diff --git a/features/mbedtls/VERSION.txt b/features/mbedtls/VERSION.txt
index 249c0cd89b..23e318506b 100644
--- a/features/mbedtls/VERSION.txt
+++ b/features/mbedtls/VERSION.txt
@@ -1 +1 @@
-mbedtls-2.15.1
+development
diff --git a/features/mbedtls/importer/Makefile b/features/mbedtls/importer/Makefile
index 046e86405e..1ba8c3c6eb 100644
--- a/features/mbedtls/importer/Makefile
+++ b/features/mbedtls/importer/Makefile
@@ -27,8 +27,8 @@
 #
 
 # Set the mbed TLS release to import (this can/should be edited before import)
-MBED_TLS_RELEASE ?= mbedtls-2.15.1
-MBED_TLS_REPO_URL ?= git@github.com:ARMmbed/mbedtls-restricted.git
+MBED_TLS_RELEASE ?= development
+MBED_TLS_REPO_URL ?= git@github.com:ARMmbed/mbedtls.git
 
 # Translate between mbed TLS namespace and mbed namespace
 TARGET_PREFIX:=../
diff --git a/features/mbedtls/importer/adjust-config.sh b/features/mbedtls/importer/adjust-config.sh
index 4d9bb1b30d..c8c3db73f5 100755
--- a/features/mbedtls/importer/adjust-config.sh
+++ b/features/mbedtls/importer/adjust-config.sh
@@ -145,9 +145,3 @@ conf unset MBEDTLS_PLATFORM_TIME_TYPE_MACRO
 # Reduce the maximal MBEDTLS_MPI_MAX_SIZE to 512 bytes,
 # which should fit RSA 4096 bit keys.
 conf set MBEDTLS_MPI_MAX_SIZE     512
-
-# The following configurations are needed for Mbed Crypto.
-# They are related to the persistent key storage feature.
-conf set MBEDTLS_PSA_CRYPTO_STORAGE_C
-conf set MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
-conf unset MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
diff --git a/features/mbedtls/inc/mbedtls/aes.h b/features/mbedtls/inc/mbedtls/aes.h
index cfb20c4fc0..94e7282d36 100644
--- a/features/mbedtls/inc/mbedtls/aes.h
+++ b/features/mbedtls/inc/mbedtls/aes.h
@@ -121,7 +121,7 @@ typedef struct mbedtls_aes_xts_context
  *                 It must be the first API called before using
  *                 the context.
  *
- * \param ctx      The AES context to initialize.
+ * \param ctx      The AES context to initialize. This must not be \c NULL.
  */
 void mbedtls_aes_init( mbedtls_aes_context *ctx );
 
@@ -129,6 +129,8 @@ void mbedtls_aes_init( mbedtls_aes_context *ctx );
  * \brief          This function releases and clears the specified AES context.
  *
  * \param ctx      The AES context to clear.
+ *                 If this is \c NULL, this function does nothing.
+ *                 Otherwise, the context must have been at least initialized.
  */
 void mbedtls_aes_free( mbedtls_aes_context *ctx );
 
@@ -139,7 +141,7 @@ void mbedtls_aes_free( mbedtls_aes_context *ctx );
  *                 It must be the first API called before using
  *                 the context.
  *
- * \param ctx      The AES XTS context to initialize.
+ * \param ctx      The AES XTS context to initialize. This must not be \c NULL.
  */
 void mbedtls_aes_xts_init( mbedtls_aes_xts_context *ctx );
 
@@ -147,6 +149,8 @@ void mbedtls_aes_xts_init( mbedtls_aes_xts_context *ctx );
  * \brief          This function releases and clears the specified AES XTS context.
  *
  * \param ctx      The AES XTS context to clear.
+ *                 If this is \c NULL, this function does nothing.
+ *                 Otherwise, the context must have been at least initialized.
  */
 void mbedtls_aes_xts_free( mbedtls_aes_xts_context *ctx );
 #endif /* MBEDTLS_CIPHER_MODE_XTS */
@@ -155,7 +159,9 @@ void mbedtls_aes_xts_free( mbedtls_aes_xts_context *ctx );
  * \brief          This function sets the encryption key.
  *
  * \param ctx      The AES context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The encryption key.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of data passed in bits. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
@@ -171,7 +177,9 @@ int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
  * \brief          This function sets the decryption key.
  *
  * \param ctx      The AES context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The decryption key.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of data passed. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
@@ -189,8 +197,10 @@ int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
  *                 sets the encryption key.
  *
  * \param ctx      The AES XTS context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The encryption key. This is comprised of the XTS key1
  *                 concatenated with the XTS key2.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of \p key passed in bits. Valid options are:
  *                 <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
  *                 <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
@@ -207,8 +217,10 @@ int mbedtls_aes_xts_setkey_enc( mbedtls_aes_xts_context *ctx,
  *                 sets the decryption key.
  *
  * \param ctx      The AES XTS context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The decryption key. This is comprised of the XTS key1
  *                 concatenated with the XTS key2.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of \p key passed in bits. Valid options are:
  *                 <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
  *                 <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
@@ -234,10 +246,13 @@ int mbedtls_aes_xts_setkey_dec( mbedtls_aes_xts_context *ctx,
  *                 call to this API with the same context.
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
- * \param input    The 16-Byte buffer holding the input data.
- * \param output   The 16-Byte buffer holding the output data.
+ * \param input    The buffer holding the input data.
+ *                 It must be readable and at least \c 16 Bytes long.
+ * \param output   The buffer where the output data will be written.
+ *                 It must be writeable and at least \c 16 Bytes long.
 
  * \return         \c 0 on success.
  */
@@ -260,8 +275,8 @@ int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
  *         mbedtls_aes_setkey_enc() or mbedtls_aes_setkey_dec() must be called
  *         before the first call to this API with the same context.
  *
- * \note   This function operates on aligned blocks, that is, the input size
- *         must be a multiple of the AES block size of 16 Bytes.
+ * \note   This function operates on full blocks, that is, the input size
+ *         must be a multiple of the AES block size of \c 16 Bytes.
  *
  * \note   Upon exit, the content of the IV is updated so that you can
  *         call the same function again on the next
@@ -272,13 +287,17 @@ int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
  * \param length   The length of the input data in Bytes. This must be a
- *                 multiple of the block size (16 Bytes).
+ *                 multiple of the block size (\c 16 Bytes).
  * \param iv       Initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
@@ -306,9 +325,10 @@ int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
  *             returns #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH.
  *
  * \param ctx          The AES XTS context to use for AES XTS operations.
+ *                     It must be initialized and bound to a key.
  * \param mode         The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                     #MBEDTLS_AES_DECRYPT.
- * \param length       The length of a data unit in bytes. This can be any
+ * \param length       The length of a data unit in Bytes. This can be any
  *                     length between 16 bytes and 2^24 bytes inclusive
  *                     (between 1 and 2^20 block cipher blocks).
  * \param data_unit    The address of the data unit encoded as an array of 16
@@ -316,15 +336,15 @@ int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
  *                     is typically the index of the block device sector that
  *                     contains the data.
  * \param input        The buffer holding the input data (which is an entire
- *                     data unit). This function reads \p length bytes from \p
+ *                     data unit). This function reads \p length Bytes from \p
  *                     input.
  * \param output       The buffer holding the output data (which is an entire
- *                     data unit). This function writes \p length bytes to \p
+ *                     data unit). This function writes \p length Bytes to \p
  *                     output.
  *
  * \return             \c 0 on success.
  * \return             #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH if \p length is
- *                     smaller than an AES block in size (16 bytes) or if \p
+ *                     smaller than an AES block in size (16 Bytes) or if \p
  *                     length is larger than 2^20 blocks (16 MiB).
  */
 int mbedtls_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
@@ -360,13 +380,18 @@ int mbedtls_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
- * \param length   The length of the input data.
+ * \param length   The length of the input data in Bytes.
  * \param iv_off   The offset in IV (updated after use).
+ *                 It must point to a valid \c size_t.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -401,12 +426,16 @@ int mbedtls_aes_crypt_cfb128( mbedtls_aes_context *ctx,
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT
  * \param length   The length of the input data.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -451,11 +480,16 @@ int mbedtls_aes_crypt_cfb8( mbedtls_aes_context *ctx,
  *              will compromise security.
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param length   The length of the input data.
  * \param iv_off   The offset in IV (updated after use).
+ *                 It must point to a valid \c size_t.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -527,15 +561,21 @@ int mbedtls_aes_crypt_ofb( mbedtls_aes_context *ctx,
  *             securely discarded as soon as it's no longer needed.
  *
  * \param ctx              The AES context to use for encryption or decryption.
+ *                         It must be initialized and bound to a key.
  * \param length           The length of the input data.
  * \param nc_off           The offset in the current \p stream_block, for
  *                         resuming within the current cipher stream. The
  *                         offset pointer should be 0 at the start of a stream.
+ *                         It must point to a valid \c size_t.
  * \param nonce_counter    The 128-bit nonce and counter.
+ *                         It must be a readable-writeable buffer of \c 16 Bytes.
  * \param stream_block     The saved stream block for resuming. This is
  *                         overwritten by the function.
+ *                         It must be a readable-writeable buffer of \c 16 Bytes.
  * \param input            The buffer holding the input data.
+ *                         It must be readable and of size \p length Bytes.
  * \param output           The buffer holding the output data.
+ *                         It must be writeable and of size \p length Bytes.
  *
  * \return                 \c 0 on success.
  */
@@ -588,7 +628,7 @@ int mbedtls_internal_aes_decrypt( mbedtls_aes_context *ctx,
  * \brief           Deprecated internal AES block encryption function
  *                  without return value.
  *
- * \deprecated      Superseded by mbedtls_aes_encrypt_ext() in 2.5.0.
+ * \deprecated      Superseded by mbedtls_internal_aes_encrypt()
  *
  * \param ctx       The AES context to use for encryption.
  * \param input     Plaintext block.
@@ -602,7 +642,7 @@ MBEDTLS_DEPRECATED void mbedtls_aes_encrypt( mbedtls_aes_context *ctx,
  * \brief           Deprecated internal AES block decryption function
  *                  without return value.
  *
- * \deprecated      Superseded by mbedtls_aes_decrypt_ext() in 2.5.0.
+ * \deprecated      Superseded by mbedtls_internal_aes_decrypt()
  *
  * \param ctx       The AES context to use for decryption.
  * \param input     Ciphertext block.
@@ -615,6 +655,8 @@ MBEDTLS_DEPRECATED void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+
+#if defined(MBEDTLS_SELF_TEST)
 /**
  * \brief          Checkup routine.
  *
@@ -623,6 +665,8 @@ MBEDTLS_DEPRECATED void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
  */
 int mbedtls_aes_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/aesni.h b/features/mbedtls/inc/mbedtls/aesni.h
index 746baa0e17..a4ca012f8a 100644
--- a/features/mbedtls/inc/mbedtls/aesni.h
+++ b/features/mbedtls/inc/mbedtls/aesni.h
@@ -2,6 +2,9 @@
  * \file aesni.h
  *
  * \brief AES-NI for hardware AES acceleration on some Intel processors
+ *
+ * \warning These functions are only for internal use by other library
+ *          functions; you must not call them directly.
  */
 /*
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
@@ -24,6 +27,12 @@
 #ifndef MBEDTLS_AESNI_H
 #define MBEDTLS_AESNI_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "aes.h"
 
 #define MBEDTLS_AESNI_AES      0x02000000u
@@ -42,7 +51,10 @@ extern "C" {
 #endif
 
 /**
- * \brief          AES-NI features detection routine
+ * \brief          Internal function to detect the AES-NI feature in CPUs.
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param what     The feature to detect
  *                 (MBEDTLS_AESNI_AES or MBEDTLS_AESNI_CLMUL)
@@ -52,7 +64,10 @@ extern "C" {
 int mbedtls_aesni_has_support( unsigned int what );
 
 /**
- * \brief          AES-NI AES-ECB block en(de)cryption
+ * \brief          Internal AES-NI AES-ECB block encryption and decryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -62,12 +77,15 @@ int mbedtls_aesni_has_support( unsigned int what );
  * \return         0 on success (cannot fail)
  */
 int mbedtls_aesni_crypt_ecb( mbedtls_aes_context *ctx,
-                     int mode,
-                     const unsigned char input[16],
-                     unsigned char output[16] );
+                             int mode,
+                             const unsigned char input[16],
+                             unsigned char output[16] );
 
 /**
- * \brief          GCM multiplication: c = a * b in GF(2^128)
+ * \brief          Internal GCM multiplication: c = a * b in GF(2^128)
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param c        Result
  * \param a        First operand
@@ -77,21 +95,29 @@ int mbedtls_aesni_crypt_ecb( mbedtls_aes_context *ctx,
  *                 elements of GF(2^128) as per the GCM spec.
  */
 void mbedtls_aesni_gcm_mult( unsigned char c[16],
-                     const unsigned char a[16],
-                     const unsigned char b[16] );
+                             const unsigned char a[16],
+                             const unsigned char b[16] );
 
 /**
- * \brief           Compute decryption round keys from encryption round keys
+ * \brief           Internal round key inversion. This function computes
+ *                  decryption round keys from the encryption round keys.
+ *
+ * \note            This function is only for internal use by other library
+ *                  functions; you must not call it directly.
  *
  * \param invkey    Round keys for the equivalent inverse cipher
  * \param fwdkey    Original round keys (for encryption)
  * \param nr        Number of rounds (that is, number of round keys minus one)
  */
 void mbedtls_aesni_inverse_key( unsigned char *invkey,
-                        const unsigned char *fwdkey, int nr );
+                                const unsigned char *fwdkey,
+                                int nr );
 
 /**
- * \brief           Perform key expansion (for encryption)
+ * \brief           Internal key expansion for encryption
+ *
+ * \note            This function is only for internal use by other library
+ *                  functions; you must not call it directly.
  *
  * \param rk        Destination buffer where the round keys are written
  * \param key       Encryption key
@@ -100,8 +126,8 @@ void mbedtls_aesni_inverse_key( unsigned char *invkey,
  * \return          0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
  */
 int mbedtls_aesni_setkey_enc( unsigned char *rk,
-                      const unsigned char *key,
-                      size_t bits );
+                              const unsigned char *key,
+                              size_t bits );
 
 #ifdef __cplusplus
 }
diff --git a/features/mbedtls/inc/mbedtls/arc4.h b/features/mbedtls/inc/mbedtls/arc4.h
index c43f4065f1..fb044d5b7f 100644
--- a/features/mbedtls/inc/mbedtls/arc4.h
+++ b/features/mbedtls/inc/mbedtls/arc4.h
@@ -123,6 +123,8 @@ void mbedtls_arc4_setup( mbedtls_arc4_context *ctx, const unsigned char *key,
 int mbedtls_arc4_crypt( mbedtls_arc4_context *ctx, size_t length, const unsigned char *input,
                 unsigned char *output );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -135,6 +137,8 @@ int mbedtls_arc4_crypt( mbedtls_arc4_context *ctx, size_t length, const unsigned
  */
 int mbedtls_arc4_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/aria.h b/features/mbedtls/inc/mbedtls/aria.h
index 483d4c2998..1e8956ed13 100644
--- a/features/mbedtls/inc/mbedtls/aria.h
+++ b/features/mbedtls/inc/mbedtls/aria.h
@@ -39,6 +39,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "platform_util.h"
+
 #define MBEDTLS_ARIA_ENCRYPT     1 /**< ARIA encryption. */
 #define MBEDTLS_ARIA_DECRYPT     0 /**< ARIA decryption. */
 
@@ -46,8 +48,12 @@
 #define MBEDTLS_ARIA_MAX_ROUNDS  16 /**< Maxiumum number of rounds in ARIA. */
 #define MBEDTLS_ARIA_MAX_KEYSIZE 32 /**< Maximum size of an ARIA key in bytes. */
 
-#define MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH   -0x005C  /**< Invalid key length. */
-#define MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH -0x005E  /**< Invalid data input length. */
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#define MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH   MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( -0x005C )
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+#define MBEDTLS_ERR_ARIA_BAD_INPUT_DATA -0x005C /**< Bad input data. */
+
+#define MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH -0x005E /**< Invalid data input length. */
 
 /* MBEDTLS_ERR_ARIA_FEATURE_UNAVAILABLE is deprecated and should not be used.
  */
@@ -85,14 +91,16 @@ mbedtls_aria_context;
  *                 It must be the first API called before using
  *                 the context.
  *
- * \param ctx      The ARIA context to initialize.
+ * \param ctx      The ARIA context to initialize. This must not be \c NULL.
  */
 void mbedtls_aria_init( mbedtls_aria_context *ctx );
 
 /**
  * \brief          This function releases and clears the specified ARIA context.
  *
- * \param ctx      The ARIA context to clear.
+ * \param ctx      The ARIA context to clear. This may be \c NULL, in which
+ *                 case this function returns immediately. If it is not \c NULL,
+ *                 it must point to an initialized ARIA context.
  */
 void mbedtls_aria_free( mbedtls_aria_context *ctx );
 
@@ -100,14 +108,16 @@ void mbedtls_aria_free( mbedtls_aria_context *ctx );
  * \brief          This function sets the encryption key.
  *
  * \param ctx      The ARIA context to which the key should be bound.
- * \param key      The encryption key.
- * \param keybits  The size of data passed in bits. Valid options are:
+ *                 This must be initialized.
+ * \param key      The encryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The size of \p key in Bits. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
  *                 <li>256 bits</li></ul>
  *
- * \return         \c 0 on success or #MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH
- *                 on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_setkey_enc( mbedtls_aria_context *ctx,
                              const unsigned char *key,
@@ -117,13 +127,16 @@ int mbedtls_aria_setkey_enc( mbedtls_aria_context *ctx,
  * \brief          This function sets the decryption key.
  *
  * \param ctx      The ARIA context to which the key should be bound.
- * \param key      The decryption key.
+ *                 This must be initialized.
+ * \param key      The decryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
  * \param keybits  The size of data passed. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
  *                 <li>256 bits</li></ul>
  *
- * \return         \c 0 on success, or #MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_setkey_dec( mbedtls_aria_context *ctx,
                              const unsigned char *key,
@@ -142,10 +155,12 @@ int mbedtls_aria_setkey_dec( mbedtls_aria_context *ctx,
  *                 call to this API with the same context.
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
+ *                 This must be initialized and bound to a key.
  * \param input    The 16-Byte buffer holding the input data.
  * \param output   The 16-Byte buffer holding the output data.
 
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_ecb( mbedtls_aria_context *ctx,
                             const unsigned char input[MBEDTLS_ARIA_BLOCKSIZE],
@@ -177,16 +192,21 @@ int mbedtls_aria_crypt_ecb( mbedtls_aria_context *ctx,
  *
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
- * \param mode     The ARIA operation: #MBEDTLS_ARIA_ENCRYPT or
- *                 #MBEDTLS_ARIA_DECRYPT.
+ *                 This must be initialized and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_ARIA_ENCRYPT for encryption, or
+ *                 #MBEDTLS_ARIA_DECRYPT for decryption.
  * \param length   The length of the input data in Bytes. This must be a
  *                 multiple of the block size (16 Bytes).
  * \param iv       Initialization vector (updated after use).
- * \param input    The buffer holding the input data.
- * \param output   The buffer holding the output data.
+ *                 This must be a readable buffer of size 16 Bytes.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must
+ *                 be a writable buffer of length \p length Bytes.
  *
- * \return         \c 0 on success, or #MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH
- *                 on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_cbc( mbedtls_aria_context *ctx,
                             int mode,
@@ -221,15 +241,22 @@ int mbedtls_aria_crypt_cbc( mbedtls_aria_context *ctx,
  *
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
- * \param mode     The ARIA operation: #MBEDTLS_ARIA_ENCRYPT or
- *                 #MBEDTLS_ARIA_DECRYPT.
- * \param length   The length of the input data.
+ *                 This must be initialized and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_ARIA_ENCRYPT for encryption, or
+ *                 #MBEDTLS_ARIA_DECRYPT for decryption.
+ * \param length   The length of the input data \p input in Bytes.
  * \param iv_off   The offset in IV (updated after use).
+ *                 This must not be larger than 15.
  * \param iv       The initialization vector (updated after use).
- * \param input    The buffer holding the input data.
- * \param output   The buffer holding the output data.
+ *                 This must be a readable buffer of size 16 Bytes.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must
+ *                 be a writable buffer of length \p length Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_cfb128( mbedtls_aria_context *ctx,
                                int mode,
@@ -299,17 +326,24 @@ int mbedtls_aria_crypt_cfb128( mbedtls_aria_context *ctx,
  *             securely discarded as soon as it's no longer needed.
  *
  * \param ctx              The ARIA context to use for encryption or decryption.
- * \param length           The length of the input data.
- * \param nc_off           The offset in the current \p stream_block, for
- *                         resuming within the current cipher stream. The
- *                         offset pointer should be 0 at the start of a stream.
- * \param nonce_counter    The 128-bit nonce and counter.
- * \param stream_block     The saved stream block for resuming. This is
- *                         overwritten by the function.
- * \param input            The buffer holding the input data.
- * \param output           The buffer holding the output data.
+ *                         This must be initialized and bound to a key.
+ * \param length           The length of the input data \p input in Bytes.
+ * \param nc_off           The offset in Bytes in the current \p stream_block,
+ *                         for resuming within the current cipher stream. The
+ *                         offset pointer should be \c 0 at the start of a
+ *                         stream. This must not be larger than \c 15 Bytes.
+ * \param nonce_counter    The 128-bit nonce and counter. This must point to
+ *                         a read/write buffer of length \c 16 bytes.
+ * \param stream_block     The saved stream block for resuming. This must
+ *                         point to a read/write buffer of length \c 16 bytes.
+ *                         This is overwritten by the function.
+ * \param input            The buffer holding the input data. This must
+ *                         be a readable buffer of length \p length Bytes.
+ * \param output           The buffer holding the output data. This must
+ *                         be a writable buffer of length \p length Bytes.
  *
- * \return     \c 0 on success.
+ * \return                 \c 0 on success.
+ * \return                 A negative error code on failure.
  */
 int mbedtls_aria_crypt_ctr( mbedtls_aria_context *ctx,
                             size_t length,
diff --git a/features/mbedtls/inc/mbedtls/asn1write.h b/features/mbedtls/inc/mbedtls/asn1write.h
index 76c1780b59..dc81782c4f 100644
--- a/features/mbedtls/inc/mbedtls/asn1write.h
+++ b/features/mbedtls/inc/mbedtls/asn1write.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_ASN1_WRITE_H
 #define MBEDTLS_ASN1_WRITE_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "asn1.h"
 
 #define MBEDTLS_ASN1_CHK_ADD(g, f)                      \
@@ -276,6 +282,28 @@ int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
 int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
                                   const unsigned char *buf, size_t bits );
 
+/**
+ * \brief           This function writes a named bitstring tag
+ *                  (#MBEDTLS_ASN1_BIT_STRING) and value in ASN.1 format.
+ *
+ *                  As stated in RFC 5280 Appendix B, trailing zeroes are
+ *                  omitted when encoding named bitstrings in DER.
+ *
+ * \note            This function works backwards within the data buffer.
+ *
+ * \param p         The reference to the current position pointer.
+ * \param start     The start of the buffer which is used for bounds-checking.
+ * \param buf       The bitstring to write.
+ * \param bits      The total number of bits in the bitstring.
+ *
+ * \return          The number of bytes written to \p p on success.
+ * \return          A negative error code on failure.
+ */
+int mbedtls_asn1_write_named_bitstring( unsigned char **p,
+                                        unsigned char *start,
+                                        const unsigned char *buf,
+                                        size_t bits );
+
 /**
  * \brief           Write an octet string tag (#MBEDTLS_ASN1_OCTET_STRING)
  *                  and value in ASN.1 format.
diff --git a/features/mbedtls/inc/mbedtls/base64.h b/features/mbedtls/inc/mbedtls/base64.h
index 7a64f52163..0d024164c5 100644
--- a/features/mbedtls/inc/mbedtls/base64.h
+++ b/features/mbedtls/inc/mbedtls/base64.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_BASE64_H
 #define MBEDTLS_BASE64_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include <stddef.h>
 
 #define MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL               -0x002A  /**< Output buffer too small. */
@@ -75,6 +81,7 @@ int mbedtls_base64_encode( unsigned char *dst, size_t dlen, size_t *olen,
 int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
                    const unsigned char *src, size_t slen );
 
+#if defined(MBEDTLS_SELF_TEST)
 /**
  * \brief          Checkup routine
  *
@@ -82,6 +89,8 @@ int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
  */
 int mbedtls_base64_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/bignum.h b/features/mbedtls/inc/mbedtls/bignum.h
index 40cfab49af..a54c18e375 100644
--- a/features/mbedtls/inc/mbedtls/bignum.h
+++ b/features/mbedtls/inc/mbedtls/bignum.h
@@ -186,96 +186,115 @@ typedef struct mbedtls_mpi
 mbedtls_mpi;
 
 /**
- * \brief           Initialize one MPI (make internal references valid)
- *                  This just makes it ready to be set or freed,
+ * \brief           Initialize an MPI context.
+ *
+ *                  This makes the MPI ready to be set or freed,
  *                  but does not define a value for the MPI.
  *
- * \param X         One MPI to initialize.
+ * \param X         The MPI context to initialize. This must not be \c NULL.
  */
 void mbedtls_mpi_init( mbedtls_mpi *X );
 
 /**
- * \brief          Unallocate one MPI
+ * \brief          This function frees the components of an MPI context.
  *
- * \param X        One MPI to unallocate.
+ * \param X        The MPI context to be cleared. This may be \c NULL,
+ *                 in which case this function is a no-op. If it is
+ *                 not \c NULL, it must point to an initialized MPI.
  */
 void mbedtls_mpi_free( mbedtls_mpi *X );
 
 /**
- * \brief          Enlarge to the specified number of limbs
+ * \brief          Enlarge an MPI to the specified number of limbs.
  *
- *                 This function does nothing if the MPI is already large enough.
+ * \note           This function does nothing if the MPI is
+ *                 already large enough.
  *
- * \param X        MPI to grow
- * \param nblimbs  The target number of limbs
+ * \param X        The MPI to grow. It must be initialized.
+ * \param nblimbs  The target number of limbs.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_grow( mbedtls_mpi *X, size_t nblimbs );
 
 /**
- * \brief          Resize down, keeping at least the specified number of limbs
+ * \brief          This function resizes an MPI downwards, keeping at least the
+ *                 specified number of limbs.
  *
  *                 If \c X is smaller than \c nblimbs, it is resized up
  *                 instead.
  *
- * \param X        MPI to shrink
- * \param nblimbs  The minimum number of limbs to keep
+ * \param X        The MPI to shrink. This must point to an initialized MPI.
+ * \param nblimbs  The minimum number of limbs to keep.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
  *                 (this can only happen when resizing up).
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_shrink( mbedtls_mpi *X, size_t nblimbs );
 
 /**
- * \brief          Copy the contents of Y into X
+ * \brief          Make a copy of an MPI.
  *
- * \param X        Destination MPI. It is enlarged if necessary.
- * \param Y        Source MPI.
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param Y        The source MPI. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \note           The limb-buffer in the destination MPI is enlarged
+ *                 if necessary to hold the value in the source MPI.
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_copy( mbedtls_mpi *X, const mbedtls_mpi *Y );
 
 /**
- * \brief          Swap the contents of X and Y
+ * \brief          Swap the contents of two MPIs.
  *
- * \param X        First MPI value
- * \param Y        Second MPI value
+ * \param X        The first MPI. It must be initialized.
+ * \param Y        The second MPI. It must be initialized.
  */
 void mbedtls_mpi_swap( mbedtls_mpi *X, mbedtls_mpi *Y );
 
 /**
- * \brief          Safe conditional assignement X = Y if assign is 1
+ * \brief          Perform a safe conditional copy of MPI which doesn't
+ *                 reveal whether the condition was true or not.
  *
- * \param X        MPI to conditionally assign to
- * \param Y        Value to be assigned
- * \param assign   1: perform the assignment, 0: keep X's original value
- *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
+ * \param X        The MPI to conditionally assign to. This must point
+ *                 to an initialized MPI.
+ * \param Y        The MPI to be assigned from. This must point to an
+ *                 initialized MPI.
+ * \param assign   The condition deciding whether to perform the
+ *                 assignment or not. Possible values:
+ *                 * \c 1: Perform the assignment `X = Y`.
+ *                 * \c 0: Keep the original value of \p X.
  *
  * \note           This function is equivalent to
- *                      if( assign ) mbedtls_mpi_copy( X, Y );
+ *                      `if( assign ) mbedtls_mpi_copy( X, Y );`
  *                 except that it avoids leaking any information about whether
  *                 the assignment was done or not (the above code may leak
  *                 information through branch prediction and/or memory access
  *                 patterns analysis).
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_safe_cond_assign( mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned char assign );
 
 /**
- * \brief          Safe conditional swap X <-> Y if swap is 1
+ * \brief          Perform a safe conditional swap which doesn't
+ *                 reveal whether the condition was true or not.
  *
- * \param X        First mbedtls_mpi value
- * \param Y        Second mbedtls_mpi value
- * \param assign   1: perform the swap, 0: keep X and Y's original values
- *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
+ * \param X        The first MPI. This must be initialized.
+ * \param Y        The second MPI. This must be initialized.
+ * \param assign   The condition deciding whether to perform
+ *                 the swap or not. Possible values:
+ *                 * \c 1: Swap the values of \p X and \p Y.
+ *                 * \c 0: Keep the original values of \p X and \p Y.
  *
  * \note           This function is equivalent to
  *                      if( assign ) mbedtls_mpi_swap( X, Y );
@@ -283,415 +302,512 @@ int mbedtls_mpi_safe_cond_assign( mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned
  *                 the assignment was done or not (the above code may leak
  *                 information through branch prediction and/or memory access
  *                 patterns analysis).
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
+ *
  */
 int mbedtls_mpi_safe_cond_swap( mbedtls_mpi *X, mbedtls_mpi *Y, unsigned char assign );
 
 /**
- * \brief          Set value from integer
+ * \brief          Store integer value in MPI.
  *
- * \param X        MPI to set
- * \param z        Value to use
+ * \param X        The MPI to set. This must be initialized.
+ * \param z        The value to use.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_lset( mbedtls_mpi *X, mbedtls_mpi_sint z );
 
 /**
- * \brief          Get a specific bit from X
+ * \brief          Get a specific bit from an MPI.
  *
- * \param X        MPI to use
- * \param pos      Zero-based index of the bit in X
+ * \param X        The MPI to query. This must be initialized.
+ * \param pos      Zero-based index of the bit to query.
  *
- * \return         Either a 0 or a 1
+ * \return         \c 0 or \c 1 on success, depending on whether bit \c pos
+ *                 of \c X is unset or set.
+ * \return         A negative error code on failure.
  */
 int mbedtls_mpi_get_bit( const mbedtls_mpi *X, size_t pos );
 
 /**
- * \brief          Set a bit of X to a specific value of 0 or 1
+ * \brief          Modify a specific bit in an MPI.
  *
- * \note           Will grow X if necessary to set a bit to 1 in a not yet
- *                 existing limb. Will not grow if bit should be set to 0
+ * \note           This function will grow the target MPI if necessary to set a
+ *                 bit to \c 1 in a not yet existing limb. It will not grow if
+ *                 the bit should be set to \c 0.
  *
- * \param X        MPI to use
- * \param pos      Zero-based index of the bit in X
- * \param val      The value to set the bit to (0 or 1)
+ * \param X        The MPI to modify. This must be initialized.
+ * \param pos      Zero-based index of the bit to modify.
+ * \param val      The desired value of bit \c pos: \c 0 or \c 1.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_BAD_INPUT_DATA if val is not 0 or 1
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_set_bit( mbedtls_mpi *X, size_t pos, unsigned char val );
 
 /**
- * \brief          Return the number of zero-bits before the least significant
- *                 '1' bit
+ * \brief          Return the number of bits of value \c 0 before the
+ *                 least significant bit of value \c 1.
  *
- * Note: Thus also the zero-based index of the least significant '1' bit
+ * \note           This is the same as the zero-based index of
+ *                 the least significant bit of value \c 1.
  *
- * \param X        MPI to use
+ * \param X        The MPI to query.
+ *
+ * \return         The number of bits of value \c 0 before the least significant
+ *                 bit of value \c 1 in \p X.
  */
 size_t mbedtls_mpi_lsb( const mbedtls_mpi *X );
 
 /**
  * \brief          Return the number of bits up to and including the most
- *                 significant '1' bit'
+ *                 significant bit of value \c 1.
  *
- * Note: Thus also the one-based index of the most significant '1' bit
+ * * \note         This is same as the one-based index of the most
+ *                 significant bit of value \c 1.
  *
- * \param X        MPI to use
+ * \param X        The MPI to query. This must point to an initialized MPI.
+ *
+ * \return         The number of bits up to and including the most
+ *                 significant bit of value \c 1.
  */
 size_t mbedtls_mpi_bitlen( const mbedtls_mpi *X );
 
 /**
- * \brief          Return the total size in bytes
+ * \brief          Return the total size of an MPI value in bytes.
  *
- * \param X        MPI to use
+ * \param X        The MPI to use. This must point to an initialized MPI.
+ *
+ * \note           The value returned by this function may be less than
+ *                 the number of bytes used to store \p X internally.
+ *                 This happens if and only if there are trailing bytes
+ *                 of value zero.
+ *
+ * \return         The least number of bytes capable of storing
+ *                 the absolute value of \p X.
  */
 size_t mbedtls_mpi_size( const mbedtls_mpi *X );
 
 /**
- * \brief          Import from an ASCII string
+ * \brief          Import an MPI from an ASCII string.
  *
- * \param X        Destination MPI
- * \param radix    Input numeric base
- * \param s        Null-terminated string buffer
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param radix    The numeric base of the input string.
+ * \param s        Null-terminated string buffer.
  *
- * \return         0 if successful, or a MBEDTLS_ERR_MPI_XXX error code
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_mpi_read_string( mbedtls_mpi *X, int radix, const char *s );
 
 /**
- * \brief          Export into an ASCII string
+ * \brief          Export an MPI to an ASCII string.
  *
- * \param X        Source MPI
- * \param radix    Output numeric base
- * \param buf      Buffer to write the string to
- * \param buflen   Length of buf
- * \param olen     Length of the string written, including final NUL byte
+ * \param X        The source MPI. This must point to an initialized MPI.
+ * \param radix    The numeric base of the output string.
+ * \param buf      The buffer to write the string to. This must be writable
+ *                 buffer of length \p buflen Bytes.
+ * \param buflen   The available size in Bytes of \p buf.
+ * \param olen     The address at which to store the length of the string
+ *                 written, including the  final \c NULL byte. This must
+ *                 not be \c NULL.
  *
- * \return         0 if successful, or a MBEDTLS_ERR_MPI_XXX error code.
- *                 *olen is always updated to reflect the amount
- *                 of data that has (or would have) been written.
+ * \note           You can call this function with `buflen == 0` to obtain the
+ *                 minimum required buffer size in `*olen`.
  *
- * \note           Call this function with buflen = 0 to obtain the
- *                 minimum required buffer size in *olen.
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if the target buffer \p buf
+ *                 is too small to hold the value of \p X in the desired base.
+ *                 In this case, `*olen` is nonetheless updated to contain the
+ *                 size of \p buf required for a successful call.
+ * \return         Another negative error code on different kinds of failure.
  */
 int mbedtls_mpi_write_string( const mbedtls_mpi *X, int radix,
                               char *buf, size_t buflen, size_t *olen );
 
 #if defined(MBEDTLS_FS_IO)
 /**
- * \brief          Read MPI from a line in an opened file
+ * \brief          Read an MPI from a line in an opened file.
  *
- * \param X        Destination MPI
- * \param radix    Input numeric base
- * \param fin      Input file handle
- *
- * \return         0 if successful, MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if
- *                 the file read buffer is too small or a
- *                 MBEDTLS_ERR_MPI_XXX error code
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param radix    The numeric base of the string representation used
+ *                 in the source line.
+ * \param fin      The input file handle to use. This must not be \c NULL.
  *
  * \note           On success, this function advances the file stream
  *                 to the end of the current line or to EOF.
  *
- *                 The function returns 0 on an empty line.
+ *                 The function returns \c 0 on an empty line.
  *
  *                 Leading whitespaces are ignored, as is a
- *                 '0x' prefix for radix 16.
+ *                 '0x' prefix for radix \c 16.
  *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if the file read buffer
+ *                 is too small.
+ * \return         Another negative error code on failure.
  */
 int mbedtls_mpi_read_file( mbedtls_mpi *X, int radix, FILE *fin );
 
 /**
- * \brief          Write X into an opened file, or stdout if fout is NULL
+ * \brief          Export an MPI into an opened file.
  *
- * \param p        Prefix, can be NULL
- * \param X        Source MPI
- * \param radix    Output numeric base
- * \param fout     Output file handle (can be NULL)
+ * \param p        A string prefix to emit prior to the MPI data.
+ *                 For example, this might be a label, or "0x" when
+ *                 printing in base \c 16. This may be \c NULL if no prefix
+ *                 is needed.
+ * \param X        The source MPI. This must point to an initialized MPI.
+ * \param radix    The numeric base to be used in the emitted string.
+ * \param fout     The output file handle. This may be \c NULL, in which case
+ *                 the output is written to \c stdout.
  *
- * \return         0 if successful, or a MBEDTLS_ERR_MPI_XXX error code
- *
- * \note           Set fout == NULL to print X on the console.
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_mpi_write_file( const char *p, const mbedtls_mpi *X, int radix, FILE *fout );
+int mbedtls_mpi_write_file( const char *p, const mbedtls_mpi *X,
+                            int radix, FILE *fout );
 #endif /* MBEDTLS_FS_IO */
 
 /**
- * \brief          Import X from unsigned binary data, big endian
+ * \brief          Import an MPI from unsigned big endian binary data.
  *
- * \param X        Destination MPI
- * \param buf      Input buffer
- * \param buflen   Input buffer size
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param buf      The input buffer. This must be a readable buffer of length
+ *                 \p buflen Bytes.
+ * \param buflen   The length of the input buffer \p p in Bytes.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf, size_t buflen );
+int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf,
+                             size_t buflen );
 
 /**
- * \brief          Export X into unsigned binary data, big endian.
- *                 Always fills the whole buffer, which will start with zeros
- *                 if the number is smaller.
+ * \brief          Export an MPI into unsigned big endian binary data
+ *                 of fixed size.
  *
- * \param X        Source MPI
- * \param buf      Output buffer
- * \param buflen   Output buffer size
+ * \param X        The source MPI. This must point to an initialized MPI.
+ * \param buf      The output buffer. This must be a writable buffer of length
+ *                 \p buflen Bytes.
+ * \param buflen   The size of the output buffer \p buf in Bytes.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if buf isn't large enough
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if \p buf isn't
+ *                 large enough to hold the value of \p X.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_write_binary( const mbedtls_mpi *X, unsigned char *buf, size_t buflen );
+int mbedtls_mpi_write_binary( const mbedtls_mpi *X, unsigned char *buf,
+                              size_t buflen );
 
 /**
- * \brief          Left-shift: X <<= count
+ * \brief          Perform a left-shift on an MPI: X <<= count
  *
- * \param X        MPI to shift
- * \param count    Amount to shift
+ * \param X        The MPI to shift. This must point to an initialized MPI.
+ * \param count    The number of bits to shift by.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
 int mbedtls_mpi_shift_l( mbedtls_mpi *X, size_t count );
 
 /**
- * \brief          Right-shift: X >>= count
+ * \brief          Perform a right-shift on an MPI: X >>= count
  *
- * \param X        MPI to shift
- * \param count    Amount to shift
+ * \param X        The MPI to shift. This must point to an initialized MPI.
+ * \param count    The number of bits to shift by.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
 int mbedtls_mpi_shift_r( mbedtls_mpi *X, size_t count );
 
 /**
- * \brief          Compare unsigned values
+ * \brief          Compare the absolute values of two MPIs.
  *
- * \param X        Left-hand MPI
- * \param Y        Right-hand MPI
+ * \param X        The left-hand MPI. This must point to an initialized MPI.
+ * \param Y        The right-hand MPI. This must point to an initialized MPI.
  *
- * \return         1 if |X| is greater than |Y|,
- *                -1 if |X| is lesser  than |Y| or
- *                 0 if |X| is equal to |Y|
+ * \return         \c 1 if `|X|` is greater than `|Y|`.
+ * \return         \c -1 if `|X|` is lesser than `|Y|`.
+ * \return         \c 0 if `|X|` is equal to `|Y|`.
  */
 int mbedtls_mpi_cmp_abs( const mbedtls_mpi *X, const mbedtls_mpi *Y );
 
 /**
- * \brief          Compare signed values
+ * \brief          Compare two MPIs.
  *
- * \param X        Left-hand MPI
- * \param Y        Right-hand MPI
+ * \param X        The left-hand MPI. This must point to an initialized MPI.
+ * \param Y        The right-hand MPI. This must point to an initialized MPI.
  *
- * \return         1 if X is greater than Y,
- *                -1 if X is lesser  than Y or
- *                 0 if X is equal to Y
+ * \return         \c 1 if \p X is greater than \p Y.
+ * \return         \c -1 if \p X is lesser than \p Y.
+ * \return         \c 0 if \p X is equal to \p Y.
  */
 int mbedtls_mpi_cmp_mpi( const mbedtls_mpi *X, const mbedtls_mpi *Y );
 
 /**
- * \brief          Compare signed values
+ * \brief          Compare an MPI with an integer.
  *
- * \param X        Left-hand MPI
- * \param z        The integer value to compare to
+ * \param X        The left-hand MPI. This must point to an initialized MPI.
+ * \param z        The integer value to compare \p X to.
  *
- * \return         1 if X is greater than z,
- *                -1 if X is lesser  than z or
- *                 0 if X is equal to z
+ * \return         \c 1 if \p X is greater than \p z.
+ * \return         \c -1 if \p X is lesser than \p z.
+ * \return         \c 0 if \p X is equal to \p z.
  */
 int mbedtls_mpi_cmp_int( const mbedtls_mpi *X, mbedtls_mpi_sint z );
 
 /**
- * \brief          Unsigned addition: X = |A| + |B|
+ * \brief          Perform an unsigned addition of MPIs: X = |A| + |B|
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first summand. This must point to an initialized MPI.
+ * \param B        The second summand. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_add_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_add_abs( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Unsigned subtraction: X = |A| - |B|
+ * \brief          Perform an unsigned subtraction of MPIs: X = |A| - |B|
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The minuend. This must point to an initialized MPI.
+ * \param B        The subtrahend. This must point to an initialized MPI.
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_NEGATIVE_VALUE if \p B is greater than \p A.
+ * \return         Another negative error code on different kinds of failure.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_NEGATIVE_VALUE if B is greater than A
  */
-int mbedtls_mpi_sub_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_sub_abs( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Signed addition: X = A + B
+ * \brief          Perform a signed addition of MPIs: X = A + B
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first summand. This must point to an initialized MPI.
+ * \param B        The second summand. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Signed subtraction: X = A - B
+ * \brief          Perform a signed subtraction of MPIs: X = A - B
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The minuend. This must point to an initialized MPI.
+ * \param B        The subtrahend. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_sub_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_sub_mpi( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Signed addition: X = A + b
+ * \brief          Perform a signed addition of an MPI and an integer: X = A + b
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param b        The integer value to add
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first summand. This must point to an initialized MPI.
+ * \param b        The second summand.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_add_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b );
+int mbedtls_mpi_add_int( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         mbedtls_mpi_sint b );
 
 /**
- * \brief          Signed subtraction: X = A - b
+ * \brief          Perform a signed subtraction of an MPI and an integer:
+ *                 X = A - b
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param b        The integer value to subtract
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The minuend. This must point to an initialized MPI.
+ * \param b        The subtrahend.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_sub_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b );
+int mbedtls_mpi_sub_int( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         mbedtls_mpi_sint b );
 
 /**
- * \brief          Baseline multiplication: X = A * B
+ * \brief          Perform a multiplication of two MPIs: X = A * B
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first factor. This must point to an initialized MPI.
+ * \param B        The second factor. This must point to an initialized MPI.
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
  */
-int mbedtls_mpi_mul_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_mul_mpi( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Baseline multiplication: X = A * b
+ * \brief          Perform a multiplication of an MPI with an unsigned integer:
+ *                 X = A * b
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param b        The unsigned integer value to multiply with
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first factor. This must point to an initialized MPI.
+ * \param b        The second factor.
  *
- * \note           b is unsigned
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
  */
-int mbedtls_mpi_mul_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint b );
+int mbedtls_mpi_mul_int( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         mbedtls_mpi_uint b );
 
 /**
- * \brief          Division by mbedtls_mpi: A = Q * B + R
+ * \brief          Perform a division with remainder of two MPIs:
+ *                 A = Q * B + R
  *
- * \param Q        Destination MPI for the quotient
- * \param R        Destination MPI for the rest value
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param Q        The destination MPI for the quotient.
+ *                 This may be \c NULL if the value of the
+ *                 quotient is not needed.
+ * \param R        The destination MPI for the remainder value.
+ *                 This may be \c NULL if the value of the
+ *                 remainder is not needed.
+ * \param A        The dividend. This must point to an initialized MPi.
+ * \param B        The divisor. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if B == 0
- *
- * \note           Either Q or R can be NULL.
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if \p B equals zero.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Division by int: A = Q * b + R
+ * \brief          Perform a division with remainder of an MPI by an integer:
+ *                 A = Q * b + R
  *
- * \param Q        Destination MPI for the quotient
- * \param R        Destination MPI for the rest value
- * \param A        Left-hand MPI
- * \param b        Integer to divide by
+ * \param Q        The destination MPI for the quotient.
+ *                 This may be \c NULL if the value of the
+ *                 quotient is not needed.
+ * \param R        The destination MPI for the remainder value.
+ *                 This may be \c NULL if the value of the
+ *                 remainder is not needed.
+ * \param A        The dividend. This must point to an initialized MPi.
+ * \param b        The divisor.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if b == 0
- *
- * \note           Either Q or R can be NULL.
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if \p b equals zero.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, mbedtls_mpi_sint b );
+int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A,
+                         mbedtls_mpi_sint b );
 
 /**
- * \brief          Modulo: R = A mod B
+ * \brief          Perform a modular reduction. R = A mod B
  *
- * \param R        Destination MPI for the rest value
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param R        The destination MPI for the residue value.
+ *                 This must point to an initialized MPI.
+ * \param A        The MPI to compute the residue of.
+ *                 This must point to an initialized MPI.
+ * \param B        The base of the modular reduction.
+ *                 This must point to an initialized MPI.
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if \p B equals zero.
+ * \return         #MBEDTLS_ERR_MPI_NEGATIVE_VALUE if \p B is negative.
+ * \return         Another negative error code on different kinds of failure.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if B == 0,
- *                 MBEDTLS_ERR_MPI_NEGATIVE_VALUE if B < 0
  */
-int mbedtls_mpi_mod_mpi( mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_mod_mpi( mbedtls_mpi *R, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B );
 
 /**
- * \brief          Modulo: r = A mod b
+ * \brief          Perform a modular reduction with respect to an integer.
+ *                 r = A mod b
  *
- * \param r        Destination mbedtls_mpi_uint
- * \param A        Left-hand MPI
- * \param b        Integer to divide by
+ * \param r        The address at which to store the residue.
+ *                 This must not be \c NULL.
+ * \param A        The MPI to compute the residue of.
+ *                 This must point to an initialized MPi.
+ * \param b        The integer base of the modular reduction.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if b == 0,
- *                 MBEDTLS_ERR_MPI_NEGATIVE_VALUE if b < 0
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if \p b equals zero.
+ * \return         #MBEDTLS_ERR_MPI_NEGATIVE_VALUE if \p b is negative.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_sint b );
+int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A,
+                         mbedtls_mpi_sint b );
 
 /**
- * \brief          Sliding-window exponentiation: X = A^E mod N
+ * \brief          Perform a sliding-window exponentiation: X = A^E mod N
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param E        Exponent MPI
- * \param N        Modular MPI
- * \param _RR      Speed-up MPI used for recalculations
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The base of the exponentiation.
+ *                 This must point to an initialized MPI.
+ * \param E        The exponent MPI. This must point to an initialized MPI.
+ * \param N        The base for the modular reduction. This must point to an
+ *                 initialized MPI.
+ * \param _RR      A helper MPI depending solely on \p N which can be used to
+ *                 speed-up multiple modular exponentiations for the same value
+ *                 of \p N. This may be \c NULL. If it is not \c NULL, it must
+ *                 point to an initialized MPI. If it hasn't been used after
+ *                 the call to mbedtls_mpi_init(), this function will compute
+ *                 the helper value and store it in \p _RR for reuse on
+ *                 subsequent calls to this function. Otherwise, the function
+ *                 will assume that \p _RR holds the helper value set by a
+ *                 previous call to mbedtls_mpi_exp_mod(), and reuse it.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_BAD_INPUT_DATA if N is negative or even or
- *                 if E is negative
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \c N is negative or
+ *                 even, or if \c E is negative.
+ * \return         Another negative error code on different kinds of failures.
  *
- * \note           _RR is used to avoid re-computing R*R mod N across
- *                 multiple calls, which speeds up things a bit. It can
- *                 be set to NULL if the extra performance is unneeded.
  */
-int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *E, const mbedtls_mpi *N, mbedtls_mpi *_RR );
+int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *E, const mbedtls_mpi *N,
+                         mbedtls_mpi *_RR );
 
 /**
- * \brief          Fill an MPI X with size bytes of random
+ * \brief          Fill an MPI with a number of random bytes.
  *
- * \param X        Destination MPI
- * \param size     Size in bytes
- * \param f_rng    RNG function
- * \param p_rng    RNG parameter
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param size     The number of random bytes to generate.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG parameter to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng doesn't need a context argument.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on failure.
  *
- * \note           The bytes obtained from the PRNG are interpreted
+ * \note           The bytes obtained from the RNG are interpreted
  *                 as a big-endian representation of an MPI; this can
  *                 be relevant in applications like deterministic ECDSA.
  */
@@ -700,30 +816,37 @@ int mbedtls_mpi_fill_random( mbedtls_mpi *X, size_t size,
                      void *p_rng );
 
 /**
- * \brief          Greatest common divisor: G = gcd(A, B)
+ * \brief          Compute the greatest common divisor: G = gcd(A, B)
  *
- * \param G        Destination MPI
- * \param A        Left-hand MPI
- * \param B        Right-hand MPI
+ * \param G        The destination MPI. This must point to an initialized MPI.
+ * \param A        The first operand. This must point to an initialized MPI.
+ * \param B        The second operand. This must point to an initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on different kinds of failure.
  */
-int mbedtls_mpi_gcd( mbedtls_mpi *G, const mbedtls_mpi *A, const mbedtls_mpi *B );
+int mbedtls_mpi_gcd( mbedtls_mpi *G, const mbedtls_mpi *A,
+                     const mbedtls_mpi *B );
 
 /**
- * \brief          Modular inverse: X = A^-1 mod N
+ * \brief          Compute the modular inverse: X = A^-1 mod N
  *
- * \param X        Destination MPI
- * \param A        Left-hand MPI
- * \param N        Right-hand MPI
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param A        The MPI to calculate the modular inverse of. This must point
+ *                 to an initialized MPI.
+ * \param N        The base of the modular inversion. This must point to an
+ *                 initialized MPI.
  *
- * \return         0 if successful,
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_BAD_INPUT_DATA if N is <= 1,
-                   MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if A has no inverse mod N.
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \p N is less than
+ *                 or equal to one.
+ * \return         #MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if \p has no modular inverse
+ *                 with respect to \p N.
  */
-int mbedtls_mpi_inv_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *N );
+int mbedtls_mpi_inv_mod( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *N );
 
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 #if defined(MBEDTLS_DEPRECATED_WARNING)
@@ -732,19 +855,23 @@ int mbedtls_mpi_inv_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
 #define MBEDTLS_DEPRECATED
 #endif
 /**
- * \brief          Miller-Rabin primality test with error probability of
- *                 2<sup>-80</sup>
+ * \brief          Perform a Miller-Rabin primality test with error
+ *                 probability of 2<sup>-80</sup>.
  *
  * \deprecated     Superseded by mbedtls_mpi_is_prime_ext() which allows
  *                 specifying the number of Miller-Rabin rounds.
  *
- * \param X        MPI to check
- * \param f_rng    RNG function
- * \param p_rng    RNG parameter
+ * \param X        The MPI to check for primality.
+ *                 This must point to an initialized MPI.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG parameter to be passed to \p f_rng.
+ *                 This may be \c NULL if \p f_rng doesn't use a
+ *                 context parameter.
  *
- * \return         0 if successful (probably prime),
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if X is not prime
+ * \return         \c 0 if successful, i.e. \p X is probably prime.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if \p X is not prime.
+ * \return         Another negative error code on other kinds of failure.
  */
 MBEDTLS_DEPRECATED int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
                           int (*f_rng)(void *, unsigned char *, size_t),
@@ -764,16 +891,20 @@ MBEDTLS_DEPRECATED int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
  *                 case when mbedtls_mpi_gen_prime calls this function), then
  *                 \p rounds can be much lower.
  *
- * \param X        MPI to check
- * \param rounds   Number of bases to perform Miller-Rabin primality test for.
- *                 The probability of returning 0 on a composite is at most
- *                 2<sup>-2*\p rounds</sup>.
- * \param f_rng    RNG function
- * \param p_rng    RNG parameter
+ * \param X        The MPI to check for primality.
+ *                 This must point to an initialized MPI.
+ * \param rounds   The number of bases to perform the Miller-Rabin primality
+ *                 test for. The probability of returning 0 on a composite is
+ *                 at most 2<sup>-2*\p rounds</sup>.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG parameter to be passed to \p f_rng.
+ *                 This may be \c NULL if \p f_rng doesn't use
+ *                 a context parameter.
  *
- * \return         0 if successful (probably prime),
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if X is not prime
+ * \return         \c 0 if successful, i.e. \p X is probably prime.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_NOT_ACCEPTABLE if \p X is not prime.
+ * \return         Another negative error code on other kinds of failure.
  */
 int mbedtls_mpi_is_prime_ext( const mbedtls_mpi *X, int rounds,
                               int (*f_rng)(void *, unsigned char *, size_t),
@@ -790,23 +921,30 @@ typedef enum {
 } mbedtls_mpi_gen_prime_flag_t;
 
 /**
- * \brief          Prime number generation
+ * \brief          Generate a prime number.
  *
- * \param X        Destination MPI
- * \param nbits    Required size of X in bits
- *                 ( 3 <= nbits <= MBEDTLS_MPI_MAX_BITS )
- * \param flags    Mask of flags of type #mbedtls_mpi_gen_prime_flag_t
- * \param f_rng    RNG function
- * \param p_rng    RNG parameter
+ * \param X        The destination MPI to store the generated prime in.
+ *                 This must point to an initialized MPi.
+ * \param nbits    The required size of the destination MPI in bits.
+ *                 This must be between \c 3 and #MBEDTLS_MPI_MAX_BITS.
+ * \param flags    A mask of flags of type #mbedtls_mpi_gen_prime_flag_t.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG parameter to be passed to \p f_rng.
+ *                 This may be \c NULL if \p f_rng doesn't use
+ *                 a context parameter.
  *
- * \return         0 if successful (probably prime),
- *                 MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed,
- *                 MBEDTLS_ERR_MPI_BAD_INPUT_DATA if nbits is < 3
+ * \return         \c 0 if successful, in which case \p X holds a
+ *                 probably prime number.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if `nbits` is not between
+ *                 \c 3 and #MBEDTLS_MPI_MAX_BITS.
  */
 int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int flags,
                    int (*f_rng)(void *, unsigned char *, size_t),
                    void *p_rng );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -814,6 +952,8 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int flags,
  */
 int mbedtls_mpi_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/blowfish.h b/features/mbedtls/inc/mbedtls/blowfish.h
index 82b772ada5..f01573dcaf 100644
--- a/features/mbedtls/inc/mbedtls/blowfish.h
+++ b/features/mbedtls/inc/mbedtls/blowfish.h
@@ -33,6 +33,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "platform_util.h"
+
 #define MBEDTLS_BLOWFISH_ENCRYPT     1
 #define MBEDTLS_BLOWFISH_DECRYPT     0
 #define MBEDTLS_BLOWFISH_MAX_KEY_BITS     448
@@ -40,14 +42,17 @@
 #define MBEDTLS_BLOWFISH_ROUNDS      16         /**< Rounds to use. When increasing this value, make sure to extend the initialisation vectors */
 #define MBEDTLS_BLOWFISH_BLOCKSIZE   8          /* Blowfish uses 64 bit blocks */
 
-#define MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH                -0x0016  /**< Invalid key length. */
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#define MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH   MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( -0x0016 )
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+#define MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA -0x0016 /**< Bad input data. */
+
+#define MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH -0x0018 /**< Invalid data input length. */
 
 /* MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED is deprecated and should not be used.
  */
 #define MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED                   -0x0017  /**< Blowfish hardware accelerator failed. */
 
-#define MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH              -0x0018  /**< Invalid data input length. */
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -71,40 +76,53 @@ mbedtls_blowfish_context;
 #endif /* MBEDTLS_BLOWFISH_ALT */
 
 /**
- * \brief          Initialize Blowfish context
+ * \brief          Initialize a Blowfish context.
  *
- * \param ctx      Blowfish context to be initialized
+ * \param ctx      The Blowfish context to be initialized.
+ *                 This must not be \c NULL.
  */
 void mbedtls_blowfish_init( mbedtls_blowfish_context *ctx );
 
 /**
- * \brief          Clear Blowfish context
+ * \brief          Clear a Blowfish context.
  *
- * \param ctx      Blowfish context to be cleared
+ * \param ctx      The Blowfish context to be cleared.
+ *                 This may be \c NULL, in which case this function
+ *                 returns immediately. If it is not \c NULL, it must
+ *                 point to an initialized Blowfish context.
  */
 void mbedtls_blowfish_free( mbedtls_blowfish_context *ctx );
 
 /**
- * \brief          Blowfish key schedule
+ * \brief          Perform a Blowfish key schedule operation.
  *
- * \param ctx      Blowfish context to be initialized
- * \param key      encryption key
- * \param keybits  must be between 32 and 448 bits
+ * \param ctx      The Blowfish context to perform the key schedule on.
+ * \param key      The encryption key. This must be a readable buffer of
+ *                 length \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be between
+ *                 \c 32 and \c 448 and a multiple of \c 8.
  *
- * \return         0 if successful, or MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx, const unsigned char *key,
                      unsigned int keybits );
 
 /**
- * \brief          Blowfish-ECB block encryption/decryption
+ * \brief          Perform a Blowfish-ECB block encryption/decryption operation.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param input    8-byte input block
- * \param output   8-byte output block
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param input    The input block. This must be a readable buffer
+ *                 of size \c 8 Bytes.
+ * \param output   The output block. This must be a writable buffer
+ *                 of size \c 8 Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_ecb( mbedtls_blowfish_context *ctx,
                         int mode,
@@ -113,9 +131,7 @@ int mbedtls_blowfish_crypt_ecb( mbedtls_blowfish_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CBC)
 /**
- * \brief          Blowfish-CBC buffer encryption/decryption
- *                 Length should be a multiple of the block
- *                 size (8 bytes)
+ * \brief          Perform a Blowfish-CBC buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -125,15 +141,22 @@ int mbedtls_blowfish_crypt_ecb( mbedtls_blowfish_context *ctx,
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param length   length of the input data
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param length   The length of the input data in Bytes. This must be
+ *                 multiple of \c 8.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 8 Bytes. It is updated by this function.
+ * \param input    The input data. This must be a readable buffer of length
+ *                 \p length Bytes.
+ * \param output   The output data. This must be a writable buffer of length
+ *                 \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_cbc( mbedtls_blowfish_context *ctx,
                         int mode,
@@ -145,7 +168,7 @@ int mbedtls_blowfish_crypt_cbc( mbedtls_blowfish_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
 /**
- * \brief          Blowfish CFB buffer encryption/decryption.
+ * \brief          Perform a Blowfish CFB buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -155,15 +178,25 @@ int mbedtls_blowfish_crypt_cbc( mbedtls_blowfish_context *ctx,
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param length   length of the input data
- * \param iv_off   offset in IV (updated after use)
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param length   The length of the input data in Bytes.
+ * \param iv_off   The offset in the initialiation vector.
+ *                 The value pointed to must be smaller than \c 8 Bytes.
+ *                 It is updated by this function to support the aforementioned
+ *                 streaming usage.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of size \c 8 Bytes. It is updated after use.
+ * \param input    The input data. This must be a readable buffer of length
+ *                 \p length Bytes.
+ * \param output   The output data. This must be a writable buffer of length
+ *                 \p length Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_cfb64( mbedtls_blowfish_context *ctx,
                           int mode,
@@ -176,7 +209,7 @@ int mbedtls_blowfish_crypt_cfb64( mbedtls_blowfish_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /**
- * \brief               Blowfish-CTR buffer encryption/decryption
+ * \brief      Perform a Blowfish-CTR buffer encryption/decryption operation.
  *
  * \warning    You must never reuse a nonce value with the same key. Doing so
  *             would void the encryption for the two messages encrypted with
@@ -219,18 +252,24 @@ int mbedtls_blowfish_crypt_cfb64( mbedtls_blowfish_context *ctx,
  *             content must not be written to insecure storage and should be
  *             securely discarded as soon as it's no longer needed.
  *
- * \param ctx           Blowfish context
- * \param length        The length of the data
+ * \param ctx           The Blowfish context to use. This must be initialized
+ *                      and bound to a key.
+ * \param length        The length of the input data in Bytes.
  * \param nc_off        The offset in the current stream_block (for resuming
- *                      within current cipher stream). The offset pointer to
- *                      should be 0 at the start of a stream.
- * \param nonce_counter The 64-bit nonce and counter.
- * \param stream_block  The saved stream-block for resuming. Is overwritten
- *                      by the function.
- * \param input         The input data stream
- * \param output        The output data stream
+ *                      within current cipher stream). The offset pointer
+ *                      should be \c 0 at the start of a stream and must be
+ *                      smaller than \c 8. It is updated by this function.
+ * \param nonce_counter The 64-bit nonce and counter. This must point to a
+ *                      read/write buffer of length \c 8 Bytes.
+ * \param stream_block  The saved stream-block for resuming. This must point to
+ *                      a read/write buffer of length \c 8 Bytes.
+ * \param input         The input data. This must be a readable buffer of
+ *                      length \p length Bytes.
+ * \param output        The output data. This must be a writable buffer of
+ *                      length \p length Bytes.
  *
- * \return         0 if successful
+ * \return              \c 0 if successful.
+ * \return              A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_ctr( mbedtls_blowfish_context *ctx,
                         size_t length,
diff --git a/features/mbedtls/inc/mbedtls/bn_mul.h b/features/mbedtls/inc/mbedtls/bn_mul.h
index 0af694c7c5..c33bd8d4ab 100644
--- a/features/mbedtls/inc/mbedtls/bn_mul.h
+++ b/features/mbedtls/inc/mbedtls/bn_mul.h
@@ -38,6 +38,12 @@
 #ifndef MBEDTLS_BN_MUL_H
 #define MBEDTLS_BN_MUL_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "bignum.h"
 
 #if defined(MBEDTLS_HAVE_ASM)
@@ -170,19 +176,19 @@
 
 #define MULADDC_INIT                        \
     asm(                                    \
-        "xorq   %%r8, %%r8          \n\t"
+        "xorq   %%r8, %%r8\n"
 
 #define MULADDC_CORE                        \
-        "movq   (%%rsi), %%rax      \n\t"   \
-        "mulq   %%rbx               \n\t"   \
-        "addq   $8,      %%rsi      \n\t"   \
-        "addq   %%rcx,   %%rax      \n\t"   \
-        "movq   %%r8,    %%rcx      \n\t"   \
-        "adcq   $0,      %%rdx      \n\t"   \
-        "nop                        \n\t"   \
-        "addq   %%rax,   (%%rdi)    \n\t"   \
-        "adcq   %%rdx,   %%rcx      \n\t"   \
-        "addq   $8,      %%rdi      \n\t"
+        "movq   (%%rsi), %%rax\n"           \
+        "mulq   %%rbx\n"                    \
+        "addq   $8, %%rsi\n"                \
+        "addq   %%rcx, %%rax\n"             \
+        "movq   %%r8, %%rcx\n"              \
+        "adcq   $0, %%rdx\n"                \
+        "nop    \n"                         \
+        "addq   %%rax, (%%rdi)\n"           \
+        "adcq   %%rdx, %%rcx\n"             \
+        "addq   $8, %%rdi\n"
 
 #define MULADDC_STOP                        \
         : "+c" (c), "+D" (d), "+S" (s)      \
@@ -750,7 +756,7 @@
         "sw     $10, %2         \n\t"   \
         : "=m" (c), "=m" (d), "=m" (s)                      \
         : "m" (s), "m" (d), "m" (c), "m" (b)                \
-        : "$9", "$10", "$11", "$12", "$13", "$14", "$15"    \
+        : "$9", "$10", "$11", "$12", "$13", "$14", "$15", "lo", "hi" \
     );
 
 #endif /* MIPS */
diff --git a/features/mbedtls/inc/mbedtls/camellia.h b/features/mbedtls/inc/mbedtls/camellia.h
index 1555867cff..3eeb66366d 100644
--- a/features/mbedtls/inc/mbedtls/camellia.h
+++ b/features/mbedtls/inc/mbedtls/camellia.h
@@ -33,11 +33,17 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "platform_util.h"
+
 #define MBEDTLS_CAMELLIA_ENCRYPT     1
 #define MBEDTLS_CAMELLIA_DECRYPT     0
 
-#define MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH           -0x0024  /**< Invalid key length. */
-#define MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH         -0x0026  /**< Invalid data input length. */
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#define MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH   MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( -0x0024 )
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+#define MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA -0x0024 /**< Bad input data. */
+
+#define MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH -0x0026 /**< Invalid data input length. */
 
 /* MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED is deprecated and should not be used.
  */
@@ -66,52 +72,68 @@ mbedtls_camellia_context;
 #endif /* MBEDTLS_CAMELLIA_ALT */
 
 /**
- * \brief          Initialize CAMELLIA context
+ * \brief          Initialize a CAMELLIA context.
  *
- * \param ctx      CAMELLIA context to be initialized
+ * \param ctx      The CAMELLIA context to be initialized.
+ *                 This must not be \c NULL.
  */
 void mbedtls_camellia_init( mbedtls_camellia_context *ctx );
 
 /**
- * \brief          Clear CAMELLIA context
+ * \brief          Clear a CAMELLIA context.
  *
- * \param ctx      CAMELLIA context to be cleared
+ * \param ctx      The CAMELLIA context to be cleared. This may be \c NULL,
+ *                 in which case this function returns immediately. If it is not
+ *                 \c NULL, it must be initialized.
  */
 void mbedtls_camellia_free( mbedtls_camellia_context *ctx );
 
 /**
- * \brief          CAMELLIA key schedule (encryption)
+ * \brief          Perform a CAMELLIA key schedule operation for encryption.
  *
- * \param ctx      CAMELLIA context to be initialized
- * \param key      encryption key
- * \param keybits  must be 128, 192 or 256
+ * \param ctx      The CAMELLIA context to use. This must be initialized.
+ * \param key      The encryption key to use. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be either \c 128,
+ *                 \c 192 or \c 256.
  *
- * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits );
+int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits );
 
 /**
- * \brief          CAMELLIA key schedule (decryption)
+ * \brief          Perform a CAMELLIA key schedule operation for decryption.
  *
- * \param ctx      CAMELLIA context to be initialized
- * \param key      decryption key
- * \param keybits  must be 128, 192 or 256
+ * \param ctx      The CAMELLIA context to use. This must be initialized.
+ * \param key      The decryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be either \c 128,
+ *                 \c 192 or \c 256.
  *
- * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits );
+int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits );
 
 /**
- * \brief          CAMELLIA-ECB block encryption/decryption
+ * \brief          Perform a CAMELLIA-ECB block encryption/decryption operation.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param input    16-byte input block
- * \param output   16-byte output block
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param input    The input block. This must be a readable buffer
+ *                 of size \c 16 Bytes.
+ * \param output   The output block. This must be a writable buffer
+ *                 of size \c 16 Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
                     int mode,
@@ -120,9 +142,7 @@ int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CBC)
 /**
- * \brief          CAMELLIA-CBC buffer encryption/decryption
- *                 Length should be a multiple of the block
- *                 size (16 bytes)
+ * \brief          Perform a CAMELLIA-CBC buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -132,15 +152,22 @@ int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param length   length of the input data
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param length   The length in Bytes of the input data \p input.
+ *                 This must be a multiple of \c 16 Bytes.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 16 Bytes. It is updated to allow streaming
+ *                 use as explained above.
+ * \param input    The buffer holding the input data. This must point to a
+ *                 readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must point to a
+ *                 writable buffer of length \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
                     int mode,
@@ -152,11 +179,14 @@ int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
 /**
- * \brief          CAMELLIA-CFB128 buffer encryption/decryption
+ * \brief          Perform a CAMELLIA-CFB128 buffer encryption/decryption
+ *                 operation.
  *
- * Note: Due to the nature of CFB you should use the same key schedule for
- * both encryption and decryption. So a context initialized with
- * mbedtls_camellia_setkey_enc() for both MBEDTLS_CAMELLIA_ENCRYPT and CAMELLIE_DECRYPT.
+ * \note           Due to the nature of CFB mode, you should use the same
+ *                 key for both encryption and decryption. In particular, calls
+ *                 to this function should be preceded by a key-schedule via
+ *                 mbedtls_camellia_setkey_enc() regardless of whether \p mode
+ *                 is #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -166,16 +196,24 @@ int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param length   length of the input data
- * \param iv_off   offset in IV (updated after use)
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param length   The length of the input data \p input. Any value is allowed.
+ * \param iv_off   The current offset in the IV. This must be smaller
+ *                 than \c 16 Bytes. It is updated after this call to allow
+ *                 the aforementioned streaming usage.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 16 Bytes. It is updated after this call to
+ *                 allow the aforementioned streaming usage.
+ * \param input    The buffer holding the input data. This must be a readable
+ *                 buffer of size \p length Bytes.
+ * \param output   The buffer to hold the output data. This must be a writable
+ *                 buffer of length \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_cfb128( mbedtls_camellia_context *ctx,
                        int mode,
@@ -188,11 +226,13 @@ int mbedtls_camellia_crypt_cfb128( mbedtls_camellia_context *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /**
- * \brief               CAMELLIA-CTR buffer encryption/decryption
+ * \brief      Perform a CAMELLIA-CTR buffer encryption/decryption operation.
  *
- * Note: Due to the nature of CTR you should use the same key schedule for
- * both encryption and decryption. So a context initialized with
- * mbedtls_camellia_setkey_enc() for both MBEDTLS_CAMELLIA_ENCRYPT and MBEDTLS_CAMELLIA_DECRYPT.
+ * *note       Due to the nature of CTR mode, you should use the same
+ *             key for both encryption and decryption. In particular, calls
+ *             to this function should be preceded by a key-schedule via
+ *             mbedtls_camellia_setkey_enc() regardless of whether \p mode
+ *             is #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
  *
  * \warning    You must never reuse a nonce value with the same key. Doing so
  *             would void the encryption for the two messages encrypted with
@@ -215,41 +255,49 @@ int mbedtls_camellia_crypt_cfb128( mbedtls_camellia_context *ctx,
  *             per-message nonce, handled by yourself, and the second one
  *             updated by this function internally.
  *
- *             For example, you might reserve the first 12 bytes for the
- *             per-message nonce, and the last 4 bytes for internal use. In that
- *             case, before calling this function on a new message you need to
- *             set the first 12 bytes of \p nonce_counter to your chosen nonce
- *             value, the last 4 to 0, and \p nc_off to 0 (which will cause \p
- *             stream_block to be ignored). That way, you can encrypt at most
- *             2**96 messages of up to 2**32 blocks each with the same key.
+ *             For example, you might reserve the first \c 12 Bytes for the
+ *             per-message nonce, and the last \c 4 Bytes for internal use.
+ *             In that case, before calling this function on a new message you
+ *             need to set the first \c 12 Bytes of \p nonce_counter to your
+ *             chosen nonce value, the last four to \c 0, and \p nc_off to \c 0
+ *             (which will cause \p stream_block to be ignored). That way, you
+ *             can encrypt at most \c 2**96 messages of up to \c 2**32 blocks
+ *             each  with the same key.
  *
  *             The per-message nonce (or information sufficient to reconstruct
- *             it) needs to be communicated with the ciphertext and must be unique.
- *             The recommended way to ensure uniqueness is to use a message
- *             counter. An alternative is to generate random nonces, but this
- *             limits the number of messages that can be securely encrypted:
- *             for example, with 96-bit random nonces, you should not encrypt
- *             more than 2**32 messages with the same key.
+ *             it) needs to be communicated with the ciphertext and must be
+ *             unique. The recommended way to ensure uniqueness is to use a
+ *             message counter. An alternative is to generate random nonces,
+ *             but this limits the number of messages that can be securely
+ *             encrypted: for example, with 96-bit random nonces, you should
+ *             not encrypt more than 2**32 messages with the same key.
  *
  *             Note that for both stategies, sizes are measured in blocks and
- *             that a CAMELLIA block is 16 bytes.
+ *             that a CAMELLIA block is \c 16 Bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
  *             content must not be written to insecure storage and should be
  *             securely discarded as soon as it's no longer needed.
  *
- * \param ctx           CAMELLIA context
- * \param length        The length of the data
- * \param nc_off        The offset in the current stream_block (for resuming
+ * \param ctx           The CAMELLIA context to use. This must be initialized
+ *                      and bound to a key.
+ * \param length        The length of the input data \p input in Bytes.
+ *                      Any value is allowed.
+ * \param nc_off        The offset in the current \p stream_block (for resuming
  *                      within current cipher stream). The offset pointer to
- *                      should be 0 at the start of a stream.
- * \param nonce_counter The 128-bit nonce and counter.
- * \param stream_block  The saved stream-block for resuming. Is overwritten
- *                      by the function.
- * \param input         The input data stream
- * \param output        The output data stream
+ *                      should be \c 0 at the start of a stream. It is updated
+ *                      at the end of this call.
+ * \param nonce_counter The 128-bit nonce and counter. This must be a read/write
+ *                      buffer of length \c 16 Bytes.
+ * \param stream_block  The saved stream-block for resuming. This must be a
+ *                      read/write buffer of length \c 16 Bytes.
+ * \param input         The input data stream. This must be a readable buffer of
+ *                      size \p length Bytes.
+ * \param output        The output data stream. This must be a writable buffer
+ *                      of size \p length Bytes.
  *
- * \return         0 if successful
+ * \return              \c 0 if successful.
+ * \return              A negative error code on failure.
  */
 int mbedtls_camellia_crypt_ctr( mbedtls_camellia_context *ctx,
                        size_t length,
@@ -260,6 +308,8 @@ int mbedtls_camellia_crypt_ctr( mbedtls_camellia_context *ctx,
                        unsigned char *output );
 #endif /* MBEDTLS_CIPHER_MODE_CTR */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -267,6 +317,8 @@ int mbedtls_camellia_crypt_ctr( mbedtls_camellia_context *ctx,
  */
 int mbedtls_camellia_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/ccm.h b/features/mbedtls/inc/mbedtls/ccm.h
index dfb1b5e566..f03e3b580e 100644
--- a/features/mbedtls/inc/mbedtls/ccm.h
+++ b/features/mbedtls/inc/mbedtls/ccm.h
@@ -49,6 +49,12 @@
 #ifndef MBEDTLS_CCM_H
 #define MBEDTLS_CCM_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "cipher.h"
 
 #define MBEDTLS_ERR_CCM_BAD_INPUT       -0x000D /**< Bad input parameters to the function. */
@@ -57,7 +63,6 @@
 /* MBEDTLS_ERR_CCM_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */
 
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -85,7 +90,7 @@ mbedtls_ccm_context;
  *                  to make references valid, and prepare the context
  *                  for mbedtls_ccm_setkey() or mbedtls_ccm_free().
  *
- * \param ctx       The CCM context to initialize.
+ * \param ctx       The CCM context to initialize. This must not be \c NULL.
  */
 void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
 
@@ -93,9 +98,10 @@ void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
  * \brief           This function initializes the CCM context set in the
  *                  \p ctx parameter and sets the encryption key.
  *
- * \param ctx       The CCM context to initialize.
+ * \param ctx       The CCM context to initialize. This must be an initialized
+ *                  context.
  * \param cipher    The 128-bit block cipher to use.
- * \param key       The encryption key.
+ * \param key       The encryption key. This must not be \c NULL.
  * \param keybits   The key size in bits. This must be acceptable by the cipher.
  *
  * \return          \c 0 on success.
@@ -110,7 +116,8 @@ int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
  * \brief   This function releases and clears the specified CCM context
  *          and underlying cipher sub-context.
  *
- * \param ctx       The CCM context to clear.
+ * \param ctx       The CCM context to clear. If this is \c NULL, the function
+ *                  has no effect. Otherwise, this must be initialized.
  */
 void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
 
@@ -123,19 +130,27 @@ void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
  *                  \p tag = \p output + \p length, and make sure that the
  *                  output buffer is at least \p length + \p tag_len wide.
  *
- * \param ctx       The CCM context to use for encryption.
+ * \param ctx       The CCM context to use for encryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. If \p add_len is greater than
+ *                  zero, \p add must be a readable buffer of at least that
+ *                  length.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than `2^16 - 2^8`.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  4, 6, 8, 10, 12, 14 or 16.
  *
@@ -161,23 +176,30 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
  *                  the tag length has to be encoded into the \p iv passed to
  *                  this function.
  *
- * \param ctx       The CCM context to use for encryption.
+ * \param ctx       The CCM context to use for encryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer of
+ *                  at least \p add_len Bytes.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  0, 4, 6, 8, 10, 12, 14 or 16.
  *
- * \warning         Passing 0 as \p tag_len means that the message is no
+ * \warning         Passing \c 0 as \p tag_len means that the message is no
  *                  longer authenticated.
  *
  * \return          \c 0 on success.
@@ -193,20 +215,27 @@ int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
  * \brief           This function performs a CCM authenticated decryption of a
  *                  buffer.
  *
- * \param ctx       The CCM context to use for decryption.
+ * \param ctx       The CCM context to use for decryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer
+ *                  of at least that \p add_len Bytes..
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
- * \param tag_len   The length of the authentication field in Bytes.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
+ * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  4, 6, 8, 10, 12, 14 or 16.
  *
  * \return          \c 0 on success. This indicates that the message is authentic.
@@ -228,23 +257,30 @@ int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
  *                  this function as \p tag_len. (\p tag needs to be adjusted
  *                  accordingly.)
  *
- * \param ctx       The CCM context to use for decryption.
+ * \param ctx       The CCM context to use for decryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer of
+ *                  at least that \p add_len Bytes.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field in Bytes.
  *                  0, 4, 6, 8, 10, 12, 14 or 16.
  *
- * \warning         Passing 0 as \p tag_len means that the message is no
+ * \warning         Passing \c 0 as \p tag_len means that the message is nos
  *                  longer authenticated.
  *
  * \return          \c 0 on success.
diff --git a/features/mbedtls/inc/mbedtls/certs.h b/features/mbedtls/inc/mbedtls/certs.h
index 8dab7b5ce8..b7c5708f85 100644
--- a/features/mbedtls/inc/mbedtls/certs.h
+++ b/features/mbedtls/inc/mbedtls/certs.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_CERTS_H
 #define MBEDTLS_CERTS_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include <stddef.h>
 
 #ifdef __cplusplus
diff --git a/features/mbedtls/inc/mbedtls/chacha20.h b/features/mbedtls/inc/mbedtls/chacha20.h
index 529f22d9c9..2ae5e6e5f4 100644
--- a/features/mbedtls/inc/mbedtls/chacha20.h
+++ b/features/mbedtls/inc/mbedtls/chacha20.h
@@ -83,13 +83,18 @@ mbedtls_chacha20_context;
  *                  \c mbedtls_chacha20_free().
  *
  * \param ctx       The ChaCha20 context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_chacha20_init( mbedtls_chacha20_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified ChaCha20 context.
+ * \brief           This function releases and clears the specified
+ *                  ChaCha20 context.
+ *
+ * \param ctx       The ChaCha20 context to clear. This may be \c NULL,
+ *                  in which case this function is a no-op. If it is not
+ *                  \c NULL, it must point to an initialized context.
  *
- * \param ctx       The ChaCha20 context to clear.
  */
 void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx );
 
@@ -102,7 +107,9 @@ void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx );
  *                  \c mbedtls_chacha_update().
  *
  * \param ctx       The ChaCha20 context to which the key should be bound.
- * \param key       The encryption/decryption key. Must be 32 bytes in length.
+ *                  It must be initialized.
+ * \param key       The encryption/decryption key. This must be \c 32 Bytes
+ *                  in length.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or key is NULL.
@@ -121,8 +128,9 @@ int mbedtls_chacha20_setkey( mbedtls_chacha20_context *ctx,
  *                  messages encrypted with the same nonce and key.
  *
  * \param ctx       The ChaCha20 context to which the nonce should be bound.
- * \param nonce     The nonce. Must be 12 bytes in size.
- * \param counter   The initial counter value. This is usually 0.
+ *                  It must be initialized and bound to a key.
+ * \param nonce     The nonce. This must be \c 12 Bytes in size.
+ * \param counter   The initial counter value. This is usually \c 0.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or nonce is
@@ -150,16 +158,16 @@ int mbedtls_chacha20_starts( mbedtls_chacha20_context* ctx,
  *                  key and nonce.
  *
  * \param ctx       The ChaCha20 context to use for encryption or decryption.
- * \param size      The length of the input data in bytes.
+ *                  It must be initialized and bound to a key and nonce.
+ * \param size      The length of the input data in Bytes.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if size == 0.
+ *                  This pointer can be \c NULL if `size == 0`.
  * \param output    The buffer holding the output data.
- *                  Must be able to hold \p size bytes.
- *                  This pointer can be NULL if size == 0.
+ *                  This must be able to hold \p size Bytes.
+ *                  This pointer can be \c NULL if `size == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if the ctx, input, or
- *                  output pointers are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx,
                              size_t size,
@@ -180,19 +188,19 @@ int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx,
  * \note            The \p input and \p output pointers must either be equal or
  *                  point to non-overlapping buffers.
  *
- * \param key       The encryption/decryption key. Must be 32 bytes in length.
- * \param nonce     The nonce. Must be 12 bytes in size.
- * \param counter   The initial counter value. This is usually 0.
- * \param size      The length of the input data in bytes.
+ * \param key       The encryption/decryption key.
+ *                  This must be \c 32 Bytes in length.
+ * \param nonce     The nonce. This must be \c 12 Bytes in size.
+ * \param counter   The initial counter value. This is usually \c 0.
+ * \param size      The length of the input data in Bytes.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if size == 0.
+ *                  This pointer can be \c NULL if `size == 0`.
  * \param output    The buffer holding the output data.
- *                  Must be able to hold \p size bytes.
- *                  This pointer can be NULL if size == 0.
+ *                  This must be able to hold \p size Bytes.
+ *                  This pointer can be \c NULL if `size == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if key, nonce, input,
- *                  or output is NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chacha20_crypt( const unsigned char key[32],
                             const unsigned char nonce[12],
diff --git a/features/mbedtls/inc/mbedtls/chachapoly.h b/features/mbedtls/inc/mbedtls/chachapoly.h
index 7de6f4e8c6..49e615d278 100644
--- a/features/mbedtls/inc/mbedtls/chachapoly.h
+++ b/features/mbedtls/inc/mbedtls/chachapoly.h
@@ -115,27 +115,29 @@ mbedtls_chachapoly_context;
  *                  all previous outputs of \c mbedtls_chachapoly_update(),
  *                  otherwise you can now safely use the plaintext.
  *
- * \param ctx       The ChachaPoly context to initialize.
+ * \param ctx       The ChachaPoly context to initialize. Must not be \c NULL.
  */
 void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified ChaCha20-Poly1305 context.
+ * \brief           This function releases and clears the specified
+ *                  ChaCha20-Poly1305 context.
  *
- * \param ctx       The ChachaPoly context to clear.
+ * \param ctx       The ChachaPoly context to clear. This may be \c NULL, in which
+ *                  case this function is a no-op.
  */
 void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx );
 
 /**
- * \brief           This function sets the ChaCha20-Poly1305 symmetric encryption key.
+ * \brief           This function sets the ChaCha20-Poly1305
+ *                  symmetric encryption key.
  *
  * \param ctx       The ChaCha20-Poly1305 context to which the key should be
- *                  bound.
- * \param key       The 256-bit (32 bytes) key.
+ *                  bound. This must be initialized.
+ * \param key       The \c 256 Bit (\c 32 Bytes) key.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p key are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
                                const unsigned char key[32] );
@@ -155,14 +157,15 @@ int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context.
- * \param nonce     The nonce/IV to use for the message. Must be 12 bytes.
+ * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
+ *                  and bound to a key.
+ * \param nonce     The nonce/IV to use for the message.
+ *                  This must be a redable buffer of length \c 12 Bytes.
  * \param mode      The operation to perform: #MBEDTLS_CHACHAPOLY_ENCRYPT or
  *                  #MBEDTLS_CHACHAPOLY_DECRYPT (discouraged, see warning).
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx,
                                const unsigned char nonce[12],
@@ -193,11 +196,12 @@ int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx,
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
- * \param aad_len   The length (in bytes) of the AAD. The length has no
+ * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
+ *                  and bound to a key.
+ * \param aad_len   The length in Bytes of the AAD. The length has no
  *                  restrictions.
  * \param aad       Buffer containing the AAD.
- *                  This pointer can be NULL if aad_len == 0.
+ *                  This pointer can be \c NULL if `aad_len == 0`.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
@@ -227,20 +231,19 @@ int mbedtls_chachapoly_update_aad( mbedtls_chachapoly_context *ctx,
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
+ * \param ctx       The ChaCha20-Poly1305 context to use. This must be initialized.
  * \param len       The length (in bytes) of the data to encrypt or decrypt.
  * \param input     The buffer containing the data to encrypt or decrypt.
- *                  This pointer can be NULL if len == 0.
- * \param output    The buffer to where the encrypted or decrypted data is written.
- *                  Must be able to hold \p len bytes.
- *                  This pointer can be NULL if len == 0.
+ *                  This pointer can be \c NULL if `len == 0`.
+ * \param output    The buffer to where the encrypted or decrypted data is
+ *                  written. This must be able to hold \p len bytes.
+ *                  This pointer can be \c NULL if `len == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx, \p input, or \p output are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
  *                  if the operation has not been started or has been
  *                  finished.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx,
                                size_t len,
@@ -251,18 +254,17 @@ int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx,
  * \brief           This function finished the ChaCha20-Poly1305 operation and
  *                  generates the MAC (authentication tag).
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
+ * \param ctx       The ChaCha20-Poly1305 context to use. This must be initialized.
  * \param mac       The buffer to where the 128-bit (16 bytes) MAC is written.
  *
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p mac are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
  *                  if the operation has not been started or has been
  *                  finished.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
                                unsigned char mac[16] );
@@ -280,20 +282,21 @@ int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
  *                  and key.
  *
  * \param ctx       The ChaCha20-Poly1305 context to use (holds the key).
+ *                  This must be initialized.
  * \param length    The length (in bytes) of the data to encrypt or decrypt.
  * \param nonce     The 96-bit (12 bytes) nonce/IV to use.
- * \param aad       The buffer containing the additional authenticated data (AAD).
- *                  This pointer can be NULL if aad_len == 0.
+ * \param aad       The buffer containing the additional authenticated
+ *                  data (AAD). This pointer can be \c NULL if `aad_len == 0`.
  * \param aad_len   The length (in bytes) of the AAD data to process.
  * \param input     The buffer containing the data to encrypt or decrypt.
- *                  This pointer can be NULL if ilen == 0.
- * \param output    The buffer to where the encrypted or decrypted data is written.
- *                  This pointer can be NULL if ilen == 0.
- * \param tag       The buffer to where the computed 128-bit (16 bytes) MAC is written.
+ *                  This pointer can be \c NULL if `ilen == 0`.
+ * \param output    The buffer to where the encrypted or decrypted data
+ *                  is written. This pointer can be \c NULL if `ilen == 0`.
+ * \param tag       The buffer to where the computed 128-bit (16 bytes) MAC
+ *                  is written. This must not be \c NULL.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if one or more of the required parameters are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx,
                                         size_t length,
@@ -312,22 +315,22 @@ int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx,
  *                  \c mbedtls_chachapoly_setkey().
  *
  * \param ctx       The ChaCha20-Poly1305 context to use (holds the key).
- * \param length    The length (in bytes) of the data to decrypt.
- * \param nonce     The 96-bit (12 bytes) nonce/IV to use.
+ * \param length    The length (in Bytes) of the data to decrypt.
+ * \param nonce     The \c 96 Bit (\c 12 bytes) nonce/IV to use.
  * \param aad       The buffer containing the additional authenticated data (AAD).
- *                  This pointer can be NULL if aad_len == 0.
+ *                  This pointer can be \c NULL if `aad_len == 0`.
  * \param aad_len   The length (in bytes) of the AAD data to process.
  * \param tag       The buffer holding the authentication tag.
+ *                  This must be a readable buffer of length \c 16 Bytes.
  * \param input     The buffer containing the data to decrypt.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  * \param output    The buffer to where the decrypted data is written.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if one or more of the required parameters are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED
  *                  if the data was not authentic.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_auth_decrypt( mbedtls_chachapoly_context *ctx,
                                      size_t length,
diff --git a/features/mbedtls/inc/mbedtls/check_config.h b/features/mbedtls/inc/mbedtls/check_config.h
index 0a6f4bf505..962d3db87e 100644
--- a/features/mbedtls/inc/mbedtls/check_config.h
+++ b/features/mbedtls/inc/mbedtls/check_config.h
@@ -50,6 +50,11 @@
     !defined(MBEDTLS_PLATFORM_SNPRINTF_MACRO)
 #define MBEDTLS_PLATFORM_SNPRINTF_ALT
 #endif
+
+#if !defined(MBEDTLS_PLATFORM_VSNPRINTF_ALT) && \
+    !defined(MBEDTLS_PLATFORM_VSNPRINTF_MACRO)
+#define MBEDTLS_PLATFORM_VSNPRINTF_ALT
+#endif
 #endif /* _WIN32 */
 
 #if defined(TARGET_LIKE_MBED) && \
@@ -109,13 +114,15 @@
 #endif
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)           && \
-    ( defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT) || \
+    ( defined(MBEDTLS_USE_PSA_CRYPTO)          || \
+      defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT) || \
       defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)     || \
       defined(MBEDTLS_ECDSA_SIGN_ALT)          || \
       defined(MBEDTLS_ECDSA_VERIFY_ALT)        || \
       defined(MBEDTLS_ECDSA_GENKEY_ALT)        || \
+      defined(MBEDTLS_ECP_INTERNAL_ALT)        || \
       defined(MBEDTLS_ECP_ALT) )
-#error "MBEDTLS_ECP_RESTARTABLE defined, but it cannot coexist with an alternative ECP implementation"
+#error "MBEDTLS_ECP_RESTARTABLE defined, but it cannot coexist with an alternative or PSA-based ECP implementation"
 #endif
 
 #if defined(MBEDTLS_ECDSA_DETERMINISTIC) && !defined(MBEDTLS_HMAC_DRBG_C)
@@ -137,6 +144,10 @@
 #error "MBEDTLS_ECP_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_PK_PARSE_C) && !defined(MBEDTLS_ASN1_PARSE_C)
+#error "MBEDTLS_PK_PARSE_C defined, but not all prerequesites"
+#endif
+
 #if defined(MBEDTLS_ENTROPY_C) && (!defined(MBEDTLS_SHA512_C) &&      \
                                     !defined(MBEDTLS_SHA256_C))
 #error "MBEDTLS_ENTROPY_C defined, but not all prerequisites"
@@ -269,6 +280,14 @@
 #error "MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) &&        \
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) &&              \
+    ( !defined(MBEDTLS_SHA256_C) &&                             \
+      !defined(MBEDTLS_SHA512_C) &&                             \
+      !defined(MBEDTLS_SHA1_C) )
+#error "!MBEDTLS_SSL_KEEP_PEER_CERTIFICATE requires MBEDTLS_SHA512_C, MBEDTLS_SHA256_C or MBEDTLS_SHA1_C"
+#endif
+
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C) &&                          \
     ( !defined(MBEDTLS_PLATFORM_C) || !defined(MBEDTLS_PLATFORM_MEMORY) )
 #error "MBEDTLS_MEMORY_BUFFER_ALLOC_C defined, but not all prerequisites"
@@ -502,6 +521,32 @@
 #error "MBEDTLS_PSA_CRYPTO_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_PSA_CRYPTO_SPM) && !defined(MBEDTLS_PSA_CRYPTO_C)
+#error "MBEDTLS_PSA_CRYPTO_SPM defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C) && defined(MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C)
+#error "Only one of MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C or MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C can be defined"
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) &&            \
+    !( defined(MBEDTLS_PSA_CRYPTO_C) &&                 \
+       ( defined(MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C) ||  \
+         defined(MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C) ) )
+#error "MBEDTLS_PSA_CRYPTO_STORAGE_C defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C) &&            \
+    !( defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) &&           \
+       defined(MBEDTLS_FS_IO) )
+#error "MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C) &&             \
+    ! defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
+#error "MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C defined, but not all prerequisites"
+#endif
+
 #if defined(MBEDTLS_RSA_C) && ( !defined(MBEDTLS_BIGNUM_C) ||         \
     !defined(MBEDTLS_OID_C) )
 #error "MBEDTLS_RSA_C defined, but not all prerequisites"
@@ -696,7 +741,7 @@
 /*
  * Avoid warning from -pedantic. This is a convenient place for this
  * workaround since this is included by every single file before the
- * #if defined(MBEDTLS_xxx_C) that results in emtpy translation units.
+ * #if defined(MBEDTLS_xxx_C) that results in empty translation units.
  */
 typedef int mbedtls_iso_c_forbids_empty_translation_units;
 
diff --git a/features/mbedtls/inc/mbedtls/cipher.h b/features/mbedtls/inc/mbedtls/cipher.h
index d6ecac6520..2d609db691 100644
--- a/features/mbedtls/inc/mbedtls/cipher.h
+++ b/features/mbedtls/inc/mbedtls/cipher.h
@@ -36,6 +36,7 @@
 #endif
 
 #include <stddef.h>
+#include "platform_util.h"
 
 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
 #define MBEDTLS_CIPHER_MODE_AEAD
@@ -354,11 +355,12 @@ const int *mbedtls_cipher_list( void );
  * \brief               This function retrieves the cipher-information
  *                      structure associated with the given cipher name.
  *
- * \param cipher_name   Name of the cipher to search for.
+ * \param cipher_name   Name of the cipher to search for. This must not be
+ *                      \c NULL.
  *
  * \return              The cipher information structure associated with the
  *                      given \p cipher_name.
- * \return              NULL if the associated cipher information is not found.
+ * \return              \c NULL if the associated cipher information is not found.
  */
 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
 
@@ -370,7 +372,7 @@ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher
  *
  * \return              The cipher information structure associated with the
  *                      given \p cipher_type.
- * \return              NULL if the associated cipher information is not found.
+ * \return              \c NULL if the associated cipher information is not found.
  */
 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
 
@@ -386,7 +388,7 @@ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher
  *
  * \return              The cipher information structure associated with the
  *                      given \p cipher_id.
- * \return              NULL if the associated cipher information is not found.
+ * \return              \c NULL if the associated cipher information is not found.
  */
 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
                                               int key_bitlen,
@@ -394,6 +396,8 @@ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_ciph
 
 /**
  * \brief               This function initializes a \p cipher_context as NONE.
+ *
+ * \param ctx           The context to be initialized. This must not be \c NULL.
  */
 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
 
@@ -401,6 +405,10 @@ void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
  * \brief               This function frees and clears the cipher-specific
  *                      context of \p ctx. Freeing \p ctx itself remains the
  *                      responsibility of the caller.
+ *
+ * \param ctx           The context to be freed. If this is \c NULL, the
+ *                      function has no effect, otherwise this must point to an
+ *                      initialized context.
  */
 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
 
@@ -409,7 +417,7 @@ void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
  * \brief               This function initializes a cipher context for
  *                      use with the given cipher primitive.
  *
- * \param ctx           The context to initialize. May not be NULL.
+ * \param ctx           The context to initialize. This must be initialized.
  * \param cipher_info   The cipher to use.
  *
  * \return              \c 0 on success.
@@ -455,15 +463,16 @@ int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
 /**
  * \brief        This function returns the block size of the given cipher.
  *
- * \param ctx    The context of the cipher. Must be initialized.
+ * \param ctx    The context of the cipher. This must be initialized.
  *
- * \return       The size of the blocks of the cipher.
- * \return       0 if \p ctx has not been initialized.
+ * \return       The block size of the underlying cipher.
+ * \return       \c 0 if \p ctx has not been initialized.
  */
 static inline unsigned int mbedtls_cipher_get_block_size(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
+    if( ctx->cipher_info == NULL )
         return 0;
 
     return ctx->cipher_info->block_size;
@@ -473,7 +482,7 @@ static inline unsigned int mbedtls_cipher_get_block_size(
  * \brief        This function returns the mode of operation for
  *               the cipher. For example, MBEDTLS_MODE_CBC.
  *
- * \param ctx    The context of the cipher. Must be initialized.
+ * \param ctx    The context of the cipher. This must be initialized.
  *
  * \return       The mode of operation.
  * \return       #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
@@ -481,7 +490,8 @@ static inline unsigned int mbedtls_cipher_get_block_size(
 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
+    if( ctx->cipher_info == NULL )
         return MBEDTLS_MODE_NONE;
 
     return ctx->cipher_info->mode;
@@ -491,7 +501,7 @@ static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
  * \brief       This function returns the size of the IV or nonce
  *              of the cipher, in Bytes.
  *
- * \param ctx   The context of the cipher. Must be initialized.
+ * \param ctx   The context of the cipher. This must be initialized.
  *
  * \return      The recommended IV size if no IV has been set.
  * \return      \c 0 for ciphers not using an IV or a nonce.
@@ -500,7 +510,8 @@ static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
 static inline int mbedtls_cipher_get_iv_size(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
+    if( ctx->cipher_info == NULL )
         return 0;
 
     if( ctx->iv_size != 0 )
@@ -512,7 +523,7 @@ static inline int mbedtls_cipher_get_iv_size(
 /**
  * \brief               This function returns the type of the given cipher.
  *
- * \param ctx           The context of the cipher. Must be initialized.
+ * \param ctx           The context of the cipher. This must be initialized.
  *
  * \return              The type of the cipher.
  * \return              #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
@@ -520,7 +531,9 @@ static inline int mbedtls_cipher_get_iv_size(
 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET(
+        ctx != NULL, MBEDTLS_CIPHER_NONE );
+    if( ctx->cipher_info == NULL )
         return MBEDTLS_CIPHER_NONE;
 
     return ctx->cipher_info->type;
@@ -530,7 +543,7 @@ static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
  * \brief               This function returns the name of the given cipher
  *                      as a string.
  *
- * \param ctx           The context of the cipher. Must be initialized.
+ * \param ctx           The context of the cipher. This must be initialized.
  *
  * \return              The name of the cipher.
  * \return              NULL if \p ctx has not been not initialized.
@@ -538,7 +551,8 @@ static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
 static inline const char *mbedtls_cipher_get_name(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
+    if( ctx->cipher_info == NULL )
         return 0;
 
     return ctx->cipher_info->name;
@@ -547,7 +561,7 @@ static inline const char *mbedtls_cipher_get_name(
 /**
  * \brief               This function returns the key length of the cipher.
  *
- * \param ctx           The context of the cipher. Must be initialized.
+ * \param ctx           The context of the cipher. This must be initialized.
  *
  * \return              The key length of the cipher in bits.
  * \return              #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
@@ -556,7 +570,9 @@ static inline const char *mbedtls_cipher_get_name(
 static inline int mbedtls_cipher_get_key_bitlen(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET(
+        ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
+    if( ctx->cipher_info == NULL )
         return MBEDTLS_KEY_LENGTH_NONE;
 
     return (int) ctx->cipher_info->key_bitlen;
@@ -565,7 +581,7 @@ static inline int mbedtls_cipher_get_key_bitlen(
 /**
  * \brief          This function returns the operation of the given cipher.
  *
- * \param ctx      The context of the cipher. Must be initialized.
+ * \param ctx      The context of the cipher. This must be initialized.
  *
  * \return         The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
  * \return         #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
@@ -573,7 +589,9 @@ static inline int mbedtls_cipher_get_key_bitlen(
 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
     const mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    MBEDTLS_INTERNAL_VALIDATE_RET(
+        ctx != NULL, MBEDTLS_OPERATION_NONE );
+    if( ctx->cipher_info == NULL )
         return MBEDTLS_OPERATION_NONE;
 
     return ctx->operation;
@@ -582,11 +600,11 @@ static inline mbedtls_operation_t mbedtls_cipher_get_operation(
 /**
  * \brief               This function sets the key to use with the given context.
  *
- * \param ctx           The generic cipher context. May not be NULL. Must have
- *                      been initialized using mbedtls_cipher_info_from_type()
- *                      or mbedtls_cipher_info_from_string().
- * \param key           The key to use.
- * \param key_bitlen    The key length to use, in bits.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      bound to a cipher information structure.
+ * \param key           The key to use. This must be a readable buffer of at
+ *                      least \p key_bitlen Bits.
+ * \param key_bitlen    The key length to use, in Bits.
  * \param operation     The operation that the key will be used for:
  *                      #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
  *
@@ -607,7 +625,8 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
  *
  *                      The default passing mode is PKCS7 padding.
  *
- * \param ctx           The generic cipher context.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      bound to a cipher information structure.
  * \param mode          The padding mode.
  *
  * \return              \c 0 on success.
@@ -627,8 +646,10 @@ int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
  * \note            Some ciphers do not use IVs nor nonce. For these
  *                  ciphers, this function has no effect.
  *
- * \param ctx       The generic cipher context.
- * \param iv        The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
+ * \param ctx       The generic cipher context. This must be initialized and
+ *                  bound to a cipher information structure.
+ * \param iv        The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
+ *                  must be a readable buffer of at least \p iv_len Bytes.
  * \param iv_len    The IV length for ciphers with variable-size IV.
  *                  This parameter is discarded by ciphers with fixed-size IV.
  *
@@ -637,12 +658,13 @@ int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
  *                  parameter-verification failure.
  */
 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
-                           const unsigned char *iv, size_t iv_len );
+                           const unsigned char *iv,
+                           size_t iv_len );
 
 /**
  * \brief         This function resets the cipher state.
  *
- * \param ctx     The generic cipher context.
+ * \param ctx     The generic cipher context. This must be initialized.
  *
  * \return        \c 0 on success.
  * \return        #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
@@ -652,16 +674,18 @@ int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
 
 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
 /**
- * \brief             This function adds additional data for AEAD ciphers.
- *                    Currently supported with GCM and ChaCha20+Poly1305.
- *                    Must be called exactly once, after mbedtls_cipher_reset().
+ * \brief               This function adds additional data for AEAD ciphers.
+ *                      Currently supported with GCM and ChaCha20+Poly1305.
+ *                      This must be called exactly once, after
+ *                      mbedtls_cipher_reset().
  *
- * \param ctx         The generic cipher context.
- * \param ad          The additional data to use.
- * \param ad_len      the Length of \p ad.
+ * \param ctx           The generic cipher context. This must be initialized.
+ * \param ad            The additional data to use. This must be a readable
+ *                      buffer of at least \p ad_len Bytes.
+ * \param ad_len        The length of \p ad in Bytes.
  *
- * \return            \c 0 on success.
- * \return            A specific error code on failure.
+ * \return              \c 0 on success.
+ * \return              A specific error code on failure.
  */
 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
                       const unsigned char *ad, size_t ad_len );
@@ -682,14 +706,17 @@ int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
  *                      mbedtls_cipher_finish(), must have \p ilen as a
  *                      multiple of the block size of the cipher.
  *
- * \param ctx           The generic cipher context.
- * \param input         The buffer holding the input data.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      bound to a key.
+ * \param input         The buffer holding the input data. This must be a
+ *                      readable buffer of at least \p ilen Bytes.
  * \param ilen          The length of the input data.
- * \param output        The buffer for the output data. Must be able to hold at
- *                      least \p ilen + block_size. Must not be the same buffer
- *                      as input.
+ * \param output        The buffer for the output data. This must be able to
+ *                      hold at least `ilen + block_size`. This must not be the
+ *                      same buffer as \p input.
  * \param olen          The length of the output data, to be updated with the
- *                      actual number of Bytes written.
+ *                      actual number of Bytes written. This must not be
+ *                      \c NULL.
  *
  * \return              \c 0 on success.
  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
@@ -709,9 +736,12 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx,
  *                      contained in it is padded to the size of
  *                      the last block, and written to the \p output buffer.
  *
- * \param ctx           The generic cipher context.
- * \param output        The buffer to write data to. Needs block_size available.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      bound to a key.
+ * \param output        The buffer to write data to. This needs to be a writable
+ *                      buffer of at least \p block_size Bytes.
  * \param olen          The length of the data written to the \p output buffer.
+ *                      This may not be \c NULL.
  *
  * \return              \c 0 on success.
  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
@@ -729,10 +759,14 @@ int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
 /**
  * \brief               This function writes a tag for AEAD ciphers.
  *                      Currently supported with GCM and ChaCha20+Poly1305.
- *                      Must be called after mbedtls_cipher_finish().
+ *                      This must be called after mbedtls_cipher_finish().
  *
- * \param ctx           The generic cipher context.
- * \param tag           The buffer to write the tag to.
+ * \param ctx           The generic cipher context. This must be initialized,
+ *                      bound to a key, and have just completed a cipher
+ *                      operation through mbedtls_cipher_finish() the tag for
+ *                      which should be written.
+ * \param tag           The buffer to write the tag to. This must be a writable
+ *                      buffer of at least \p tag_len Bytes.
  * \param tag_len       The length of the tag to write.
  *
  * \return              \c 0 on success.
@@ -744,10 +778,11 @@ int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
 /**
  * \brief               This function checks the tag for AEAD ciphers.
  *                      Currently supported with GCM and ChaCha20+Poly1305.
- *                      Must be called after mbedtls_cipher_finish().
+ *                      This must be called after mbedtls_cipher_finish().
  *
- * \param ctx           The generic cipher context.
- * \param tag           The buffer holding the tag.
+ * \param ctx           The generic cipher context. This must be initialized.
+ * \param tag           The buffer holding the tag. This must be a readable
+ *                      buffer of at least \p tag_len Bytes.
  * \param tag_len       The length of the tag to check.
  *
  * \return              \c 0 on success.
@@ -761,18 +796,22 @@ int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
  * \brief               The generic all-in-one encryption/decryption function,
  *                      for all ciphers except AEAD constructs.
  *
- * \param ctx           The generic cipher context.
+ * \param ctx           The generic cipher context. This must be initialized.
  * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
+ *                      This must be a readable buffer of at least \p iv_len
+ *                      Bytes.
  * \param iv_len        The IV length for ciphers with variable-size IV.
  *                      This parameter is discarded by ciphers with fixed-size
  *                      IV.
- * \param input         The buffer holding the input data.
- * \param ilen          The length of the input data.
- * \param output        The buffer for the output data. Must be able to hold at
- *                      least \p ilen + block_size. Must not be the same buffer
- *                      as input.
+ * \param input         The buffer holding the input data. This must be a
+ *                      readable buffer of at least \p ilen Bytes.
+ * \param ilen          The length of the input data in Bytes.
+ * \param output        The buffer for the output data. This must be able to
+ *                      hold at least `ilen + block_size`. This must not be the
+ *                      same buffer as \p input.
  * \param olen          The length of the output data, to be updated with the
- *                      actual number of Bytes written.
+ *                      actual number of Bytes written. This must not be
+ *                      \c NULL.
  *
  * \note                Some ciphers do not use IVs nor nonce. For these
  *                      ciphers, use \p iv = NULL and \p iv_len = 0.
@@ -793,27 +832,34 @@ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
 
 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
 /**
- * \brief             The generic autenticated encryption (AEAD) function.
+ * \brief               The generic autenticated encryption (AEAD) function.
  *
- * \param ctx         The generic cipher context.
- * \param iv          The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
- * \param iv_len      The IV length for ciphers with variable-size IV.
- *                    This parameter is discarded by ciphers with fixed-size IV.
- * \param ad          The additional data to authenticate.
- * \param ad_len      The length of \p ad.
- * \param input       The buffer holding the input data.
- * \param ilen        The length of the input data.
- * \param output      The buffer for the output data.
- *                    Must be able to hold at least \p ilen.
- * \param olen        The length of the output data, to be updated with the
- *                    actual number of Bytes written.
- * \param tag         The buffer for the authentication tag.
- * \param tag_len     The desired length of the authentication tag.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      bound to a key.
+ * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
+ *                      This must be a readable buffer of at least \p iv_len
+ *                      Bytes.
+ * \param iv_len        The IV length for ciphers with variable-size IV.
+ *                      This parameter is discarded by ciphers with fixed-size IV.
+ * \param ad            The additional data to authenticate. This must be a
+ *                      readable buffer of at least \p ad_len Bytes.
+ * \param ad_len        The length of \p ad.
+ * \param input         The buffer holding the input data. This must be a
+ *                      readable buffer of at least \p ilen Bytes.
+ * \param ilen          The length of the input data.
+ * \param output        The buffer for the output data. This must be able to
+ *                      hold at least \p ilen Bytes.
+ * \param olen          The length of the output data, to be updated with the
+ *                      actual number of Bytes written. This must not be
+ *                      \c NULL.
+ * \param tag           The buffer for the authentication tag. This must be a
+ *                      writable buffer of at least \p tag_len Bytes.
+ * \param tag_len       The desired length of the authentication tag.
  *
- * \return            \c 0 on success.
- * \return            #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
- *                    parameter-verification failure.
- * \return            A cipher-specific error code on failure.
+ * \return              \c 0 on success.
+ * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
+ *                      parameter-verification failure.
+ * \return              A cipher-specific error code on failure.
  */
 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
                          const unsigned char *iv, size_t iv_len,
@@ -823,32 +869,39 @@ int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
                          unsigned char *tag, size_t tag_len );
 
 /**
- * \brief             The generic autenticated decryption (AEAD) function.
+ * \brief               The generic autenticated decryption (AEAD) function.
  *
- * \note              If the data is not authentic, then the output buffer
- *                    is zeroed out to prevent the unauthentic plaintext being
- *                    used, making this interface safer.
+ * \note                If the data is not authentic, then the output buffer
+ *                      is zeroed out to prevent the unauthentic plaintext being
+ *                      used, making this interface safer.
  *
- * \param ctx         The generic cipher context.
- * \param iv          The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
- * \param iv_len      The IV length for ciphers with variable-size IV.
- *                    This parameter is discarded by ciphers with fixed-size IV.
- * \param ad          The additional data to be authenticated.
- * \param ad_len      The length of \p ad.
- * \param input       The buffer holding the input data.
- * \param ilen        The length of the input data.
- * \param output      The buffer for the output data.
- *                    Must be able to hold at least \p ilen.
- * \param olen        The length of the output data, to be updated with the
- *                    actual number of Bytes written.
- * \param tag         The buffer holding the authentication tag.
- * \param tag_len     The length of the authentication tag.
+ * \param ctx           The generic cipher context. This must be initialized and
+ *                      and bound to a key.
+ * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
+ *                      This must be a readable buffer of at least \p iv_len
+ *                      Bytes.
+ * \param iv_len        The IV length for ciphers with variable-size IV.
+ *                      This parameter is discarded by ciphers with fixed-size IV.
+ * \param ad            The additional data to be authenticated. This must be a
+ *                      readable buffer of at least \p ad_len Bytes.
+ * \param ad_len        The length of \p ad.
+ * \param input         The buffer holding the input data. This must be a
+ *                      readable buffer of at least \p ilen Bytes.
+ * \param ilen          The length of the input data.
+ * \param output        The buffer for the output data.
+ *                      This must be able to hold at least \p ilen Bytes.
+ * \param olen          The length of the output data, to be updated with the
+ *                      actual number of Bytes written. This must not be
+ *                      \c NULL.
+ * \param tag           The buffer holding the authentication tag. This must be
+ *                      a readable buffer of at least \p tag_len Bytes.
+ * \param tag_len       The length of the authentication tag.
  *
- * \return            \c 0 on success.
- * \return            #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
- *                    parameter-verification failure.
- * \return            #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
- * \return            A cipher-specific error code on failure.
+ * \return              \c 0 on success.
+ * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
+ *                      parameter-verification failure.
+ * \return              #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
+ * \return              A cipher-specific error code on failure.
  */
 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
                          const unsigned char *iv, size_t iv_len,
diff --git a/features/mbedtls/inc/mbedtls/cipher_internal.h b/features/mbedtls/inc/mbedtls/cipher_internal.h
index 6687b362de..d711339004 100644
--- a/features/mbedtls/inc/mbedtls/cipher_internal.h
+++ b/features/mbedtls/inc/mbedtls/cipher_internal.h
@@ -137,7 +137,7 @@ typedef enum
 typedef struct
 {
     psa_algorithm_t alg;
-    psa_key_slot_t slot;
+    psa_key_handle_t slot;
     mbedtls_cipher_psa_key_ownership slot_state;
 } mbedtls_cipher_context_psa;
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
diff --git a/features/mbedtls/inc/mbedtls/cmac.h b/features/mbedtls/inc/mbedtls/cmac.h
index c196793531..9d42b3f209 100644
--- a/features/mbedtls/inc/mbedtls/cmac.h
+++ b/features/mbedtls/inc/mbedtls/cmac.h
@@ -28,6 +28,12 @@
 #ifndef MBEDTLS_CMAC_H
 #define MBEDTLS_CMAC_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "cipher.h"
 
 #ifdef __cplusplus
diff --git a/features/mbedtls/inc/mbedtls/compat-1.3.h b/features/mbedtls/inc/mbedtls/compat-1.3.h
index 213b691403..a58b47243d 100644
--- a/features/mbedtls/inc/mbedtls/compat-1.3.h
+++ b/features/mbedtls/inc/mbedtls/compat-1.3.h
@@ -25,6 +25,12 @@
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
 
 #if defined(MBEDTLS_DEPRECATED_WARNING)
diff --git a/features/mbedtls/inc/mbedtls/config.h b/features/mbedtls/inc/mbedtls/config.h
index b7e6470502..143b43c004 100644
--- a/features/mbedtls/inc/mbedtls/config.h
+++ b/features/mbedtls/inc/mbedtls/config.h
@@ -155,7 +155,7 @@
  *
  * System has time.h, time(), and an implementation for
  * mbedtls_platform_gmtime_r() (see below).
- * The time needs to be correct (not necesarily very accurate, but at least
+ * The time needs to be correct (not necessarily very accurate, but at least
  * the date should be correct). This is used to verify the validity period of
  * X.509 certificates.
  *
@@ -242,6 +242,7 @@
 //#define MBEDTLS_PLATFORM_FPRINTF_ALT
 //#define MBEDTLS_PLATFORM_PRINTF_ALT
 //#define MBEDTLS_PLATFORM_SNPRINTF_ALT
+//#define MBEDTLS_PLATFORM_VSNPRINTF_ALT
 //#define MBEDTLS_PLATFORM_NV_SEED_ALT
 //#define MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT
 
@@ -272,6 +273,48 @@
  */
 //#define MBEDTLS_DEPRECATED_REMOVED
 
+/**
+ * \def MBEDTLS_CHECK_PARAMS
+ *
+ * This configuration option controls whether the library validates more of
+ * the parameters passed to it.
+ *
+ * When this flag is not defined, the library only attempts to validate an
+ * input parameter if: (1) they may come from the outside world (such as the
+ * network, the filesystem, etc.) or (2) not validating them could result in
+ * internal memory errors such as overflowing a buffer controlled by the
+ * library. On the other hand, it doesn't attempt to validate parameters whose
+ * values are fully controlled by the application (such as pointers).
+ *
+ * When this flag is defined, the library additionally attempts to validate
+ * parameters that are fully controlled by the application, and should always
+ * be valid if the application code is fully correct and trusted.
+ *
+ * For example, when a function accepts as input a pointer to a buffer that may
+ * contain untrusted data, and its documentation mentions that this pointer
+ * must not be NULL:
+ * - the pointer is checked to be non-NULL only if this option is enabled
+ * - the content of the buffer is always validated
+ *
+ * When this flag is defined, if a library function receives a parameter that
+ * is invalid, it will:
+ * - invoke the macro MBEDTLS_PARAM_FAILED() which by default expands to a
+ *   call to the function mbedtls_param_failed()
+ * - immediately return (with a specific error code unless the function
+ *   returns void and can't communicate an error).
+ *
+ * When defining this flag, you also need to:
+ * - either provide a definition of the function mbedtls_param_failed() in
+ *   your application (see platform_util.h for its prototype) as the library
+ *   calls that function, but does not provide a default definition for it,
+ * - or provide a different definition of the macro MBEDTLS_PARAM_FAILED()
+ *   below if the above mechanism is not flexible enough to suit your needs.
+ *   See the documentation of this macro later in this file.
+ *
+ * Uncomment to enable validation of application-controlled parameters.
+ */
+//#define MBEDTLS_CHECK_PARAMS
+
 /* \} name SECTION: System support */
 
 /**
@@ -375,7 +418,7 @@
  * \note Because of a signature change, the core AES encryption and decryption routines are
  *       currently named mbedtls_aes_internal_encrypt and mbedtls_aes_internal_decrypt,
  *       respectively. When setting up alternative implementations, these functions should
- *       be overriden, but the wrapper functions mbedtls_aes_decrypt and mbedtls_aes_encrypt
+ *       be overridden, but the wrapper functions mbedtls_aes_decrypt and mbedtls_aes_encrypt
  *       must stay untouched.
  *
  * \note If you use the AES_xxx_ALT macros, then is is recommended to also set
@@ -430,11 +473,11 @@
  *      unsigned char mbedtls_internal_ecp_grp_capable(
  *          const mbedtls_ecp_group *grp )
  *      int  mbedtls_internal_ecp_init( const mbedtls_ecp_group *grp )
- *      void mbedtls_internal_ecp_deinit( const mbedtls_ecp_group *grp )
+ *      void mbedtls_internal_ecp_free( const mbedtls_ecp_group *grp )
  * The mbedtls_internal_ecp_grp_capable function should return 1 if the
  * replacement functions implement arithmetic for the given group and 0
  * otherwise.
- * The functions mbedtls_internal_ecp_init and mbedtls_internal_ecp_deinit are
+ * The functions mbedtls_internal_ecp_init and mbedtls_internal_ecp_free are
  * called before and after each point operation and provide an opportunity to
  * implement optimized set up and tear down instructions.
  *
@@ -660,6 +703,26 @@
  */
 #define MBEDTLS_REMOVE_ARC4_CIPHERSUITES
 
+/**
+ * \def MBEDTLS_REMOVE_3DES_CIPHERSUITES
+ *
+ * Remove 3DES ciphersuites by default in SSL / TLS.
+ * This flag removes the ciphersuites based on 3DES from the default list as
+ * returned by mbedtls_ssl_list_ciphersuites(). However, it is still possible
+ * to enable (some of) them with mbedtls_ssl_conf_ciphersuites() by including
+ * them explicitly.
+ *
+ * A man-in-the-browser attacker can recover authentication tokens sent through
+ * a TLS connection using a 3DES based cipher suite (see "On the Practical
+ * (In-)Security of 64-bit Block Ciphers" by Karthikeyan Bhargavan and Gaëtan
+ * Leurent, see https://sweet32.info/SWEET32_CCS16.pdf). If this attack falls
+ * in your threat model or you are unsure, then you should keep this option
+ * enabled to remove 3DES based cipher suites.
+ *
+ * Comment this macro to keep 3DES in the default ciphersuite list.
+ */
+#define MBEDTLS_REMOVE_3DES_CIPHERSUITES
+
 /**
  * \def MBEDTLS_ECP_DP_SECP192R1_ENABLED
  *
@@ -1175,6 +1238,30 @@
  */
 #define MBEDTLS_PKCS1_V21
 
+/**
+ * \def MBEDTLS_PSA_CRYPTO_SPM
+ *
+ * When MBEDTLS_PSA_CRYPTO_SPM is defined, the code is built for SPM (Secure
+ * Partition Manager) integration which separates the code into two parts: a
+ * NSPE (Non-Secure Process Environment) and an SPE (Secure Process
+ * Environment).
+ *
+ * Module:  library/psa_crypto.c
+ * Requires: MBEDTLS_PSA_CRYPTO_C
+ *
+ */
+//#define MBEDTLS_PSA_CRYPTO_SPM
+
+/**
+ * \def MBEDTLS_PSA_HAS_ITS_IO
+ *
+ * Enable the non-volatile secure storage usage.
+ *
+ * This is crucial on systems that do not have a HW TRNG support.
+ *
+ */
+//#define MBEDTLS_PSA_HAS_ITS_IO
+
 /**
  * \def MBEDTLS_RSA_NO_CRT
  *
@@ -1303,6 +1390,28 @@
  */
 //#define MBEDTLS_SSL_FALLBACK_SCSV
 
+/**
+ * \def MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
+ *
+ * This option controls the availability of the API mbedtls_ssl_get_peer_cert()
+ * giving access to the peer's certificate after completion of the handshake.
+ *
+ * Unless you need mbedtls_ssl_peer_cert() in your application, it is
+ * recommended to disable this option for reduced RAM usage.
+ *
+ * \note If this option is disabled, mbedtls_ssl_get_peer_cert() is still
+ *       defined, but always returns \c NULL.
+ *
+ * \note This option has no influence on the protection against the
+ *       triple handshake attack. Even if it is disabled, Mbed TLS will
+ *       still ensure that certificates do not change during renegotiation,
+ *       for exaple by keeping a hash of the peer's certificate.
+ *
+ * Comment this macro to disable storing the peer's certificate
+ * after the handshake.
+ */
+#define MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
+
 /**
  * \def MBEDTLS_SSL_HW_RECORD_ACCEL
  *
@@ -1512,7 +1621,7 @@
  * \def MBEDTLS_SSL_SESSION_TICKETS
  *
  * Enable support for RFC 5077 session tickets in SSL.
- * Client-side, provides full support for session tickets (maintainance of a
+ * Client-side, provides full support for session tickets (maintenance of a
  * session store remains the responsibility of the application, though).
  * Server-side, you also need to provide callbacks for writing and parsing
  * tickets, including authenticated encryption and key management. Example
@@ -1696,7 +1805,7 @@
  *
  * \warning TLS-level compression MAY REDUCE SECURITY! See for example the
  * CRIME attack. Before enabling this option, you should examine with care if
- * CRIME or similar exploits may be a applicable to your use case.
+ * CRIME or similar exploits may be applicable to your use case.
  *
  * \note Currently compression can't be used with DTLS.
  *
@@ -2643,6 +2752,46 @@
  */
 //#define MBEDTLS_PSA_CRYPTO_C
 
+/**
+ * \def MBEDTLS_PSA_CRYPTO_STORAGE_C
+ *
+ * Enable the Platform Security Architecture persistent key storage.
+ *
+ * Module:  library/psa_crypto_storage.c
+ *
+ * Requires: MBEDTLS_PSA_CRYPTO_C and one of either
+ * MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C or MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
+ * (but not both)
+ *
+ */
+//#define MBEDTLS_PSA_CRYPTO_STORAGE_C
+
+/**
+ * \def MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+ *
+ * Enable persistent key storage over files for the
+ * Platform Security Architecture cryptography API.
+ *
+ * Module:  library/psa_crypto_storage_file.c
+ *
+ * Requires: MBEDTLS_PSA_CRYPTO_C, MBEDTLS_FS_IO
+ *
+ */
+//#define MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+
+/**
+ * \def MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
+ *
+ * Enable persistent key storage over PSA ITS for the
+ * Platform Security Architecture cryptography API.
+ *
+ * Module:  library/psa_crypto_storage_its.c
+ *
+ * Requires: MBEDTLS_PSA_CRYPTO_C, MBEDTLS_PSA_HAS_ITS_IO
+ *
+ */
+//#define MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
+
 /**
  * \def MBEDTLS_RIPEMD160_C
  *
@@ -2990,7 +3139,7 @@
 
 /* MPI / BIGNUM options */
 //#define MBEDTLS_MPI_WINDOW_SIZE            6 /**< Maximum windows size used. */
-//#define MBEDTLS_MPI_MAX_SIZE            1024 /**< Maximum number of bytes for usable MPIs. */
+#define MBEDTLS_MPI_MAX_SIZE 512
 
 /* CTR_DRBG options */
 //#define MBEDTLS_CTR_DRBG_ENTROPY_LEN               48 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
@@ -3027,7 +3176,7 @@
 //#define MBEDTLS_PLATFORM_STD_TIME            time /**< Default time to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 //#define MBEDTLS_PLATFORM_STD_FPRINTF      fprintf /**< Default fprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_PRINTF        printf /**< Default printf to use, can be undefined */
-/* Note: your snprintf must correclty zero-terminate the buffer! */
+/* Note: your snprintf must correctly zero-terminate the buffer! */
 //#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_SUCCESS       0 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_FAILURE       1 /**< Default exit value to use, can be undefined */
@@ -3044,11 +3193,42 @@
 //#define MBEDTLS_PLATFORM_TIME_TYPE_MACRO       time_t /**< Default time macro to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 //#define MBEDTLS_PLATFORM_FPRINTF_MACRO      fprintf /**< Default fprintf macro to use, can be undefined */
 //#define MBEDTLS_PLATFORM_PRINTF_MACRO        printf /**< Default printf macro to use, can be undefined */
-/* Note: your snprintf must correclty zero-terminate the buffer! */
+/* Note: your snprintf must correctly zero-terminate the buffer! */
 //#define MBEDTLS_PLATFORM_SNPRINTF_MACRO    snprintf /**< Default snprintf macro to use, can be undefined */
+//#define MBEDTLS_PLATFORM_VSNPRINTF_MACRO    vsnprintf /**< Default vsnprintf macro to use, can be undefined */
 //#define MBEDTLS_PLATFORM_NV_SEED_READ_MACRO   mbedtls_platform_std_nv_seed_read /**< Default nv_seed_read function to use, can be undefined */
 //#define MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO  mbedtls_platform_std_nv_seed_write /**< Default nv_seed_write function to use, can be undefined */
 
+/**
+ * \brief       This macro is invoked by the library when an invalid parameter
+ *              is detected that is only checked with MBEDTLS_CHECK_PARAMS
+ *              (see the documentation of that option for context).
+ *
+ *              When you leave this undefined here, a default definition is
+ *              provided that invokes the function mbedtls_param_failed(),
+ *              which is declared in platform_util.h for the benefit of the
+ *              library, but that you need to define in your application.
+ *
+ *              When you define this here, this replaces the default
+ *              definition in platform_util.h (which no longer declares the
+ *              function mbedtls_param_failed()) and it is your responsibility
+ *              to make sure this macro expands to something suitable (in
+ *              particular, that all the necessary declarations are visible
+ *              from within the library - you can ensure that by providing
+ *              them in this file next to the macro definition).
+ *
+ *              Note that you may define this macro to expand to nothing, in
+ *              which case you don't have to worry about declarations or
+ *              definitions. However, you will then be notified about invalid
+ *              parameters only in non-void functions, and void function will
+ *              just silently return early on invalid parameters, which
+ *              partially negates the benefits of enabling
+ *              #MBEDTLS_CHECK_PARAMS in the first place, so is discouraged.
+ *
+ * \param cond  The expression that should evaluate to true, but doesn't.
+ */
+//#define MBEDTLS_PARAM_FAILED( cond )               assert( cond )
+
 /* SSL Cache options */
 //#define MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT       86400 /**< 1 day  */
 //#define MBEDTLS_SSL_CACHE_DEFAULT_MAX_ENTRIES      50 /**< Maximum entries in cache */
@@ -3057,31 +3237,65 @@
 
 /** \def MBEDTLS_SSL_MAX_CONTENT_LEN
  *
- * Maximum fragment length in bytes.
+ * Maximum length (in bytes) of incoming and outgoing plaintext fragments.
  *
- * Determines the size of both the incoming and outgoing TLS I/O buffers.
+ * This determines the size of both the incoming and outgoing TLS I/O buffers
+ * in such a way that both are capable of holding the specified amount of
+ * plaintext data, regardless of the protection mechanism used.
  *
- * Uncommenting MBEDTLS_SSL_IN_CONTENT_LEN and/or MBEDTLS_SSL_OUT_CONTENT_LEN
- * will override this length by setting maximum incoming and/or outgoing
- * fragment length, respectively.
+ * To configure incoming and outgoing I/O buffers separately, use
+ * #MBEDTLS_SSL_IN_CONTENT_LEN and #MBEDTLS_SSL_OUT_CONTENT_LEN,
+ * which overwrite the value set by this option.
+ *
+ * \note When using a value less than the default of 16KB on the client, it is
+ *       recommended to use the Maximum Fragment Length (MFL) extension to
+ *       inform the server about this limitation. On the server, there
+ *       is no supported, standardized way of informing the client about
+ *       restriction on the maximum size of incoming messages, and unless
+ *       the limitation has been communicated by other means, it is recommended
+ *       to only change the outgoing buffer size #MBEDTLS_SSL_OUT_CONTENT_LEN
+ *       while keeping the default value of 16KB for the incoming buffer.
+ *
+ * Uncomment to set the maximum plaintext size of both
+ * incoming and outgoing I/O buffers.
  */
 //#define MBEDTLS_SSL_MAX_CONTENT_LEN             16384
 
 /** \def MBEDTLS_SSL_IN_CONTENT_LEN
  *
- * Maximum incoming fragment length in bytes.
+ * Maximum length (in bytes) of incoming plaintext fragments.
  *
- * Uncomment to set the size of the inward TLS buffer independently of the
- * outward buffer.
+ * This determines the size of the incoming TLS I/O buffer in such a way
+ * that it is capable of holding the specified amount of plaintext data,
+ * regardless of the protection mechanism used.
+ *
+ * If this option is undefined, it inherits its value from
+ * #MBEDTLS_SSL_MAX_CONTENT_LEN.
+ *
+ * \note When using a value less than the default of 16KB on the client, it is
+ *       recommended to use the Maximum Fragment Length (MFL) extension to
+ *       inform the server about this limitation. On the server, there
+ *       is no supported, standardized way of informing the client about
+ *       restriction on the maximum size of incoming messages, and unless
+ *       the limitation has been communicated by other means, it is recommended
+ *       to only change the outgoing buffer size #MBEDTLS_SSL_OUT_CONTENT_LEN
+ *       while keeping the default value of 16KB for the incoming buffer.
+ *
+ * Uncomment to set the maximum plaintext size of the incoming I/O buffer
+ * independently of the outgoing I/O buffer.
  */
 //#define MBEDTLS_SSL_IN_CONTENT_LEN              16384
 
 /** \def MBEDTLS_SSL_OUT_CONTENT_LEN
  *
- * Maximum outgoing fragment length in bytes.
+ * Maximum length (in bytes) of outgoing plaintext fragments.
  *
- * Uncomment to set the size of the outward TLS buffer independently of the
- * inward buffer.
+ * This determines the size of the outgoing TLS I/O buffer in such a way
+ * that it is capable of holding the specified amount of plaintext data,
+ * regardless of the protection mechanism used.
+ *
+ * If this option undefined, it inherits its value from
+ * #MBEDTLS_SSL_MAX_CONTENT_LEN.
  *
  * It is possible to save RAM by setting a smaller outward buffer, while keeping
  * the default inward 16384 byte buffer to conform to the TLS specification.
@@ -3091,11 +3305,8 @@
  * The specific size requirement depends on the configured ciphers and any
  * certificate data which is sent during the handshake.
  *
- * For absolute minimum RAM usage, it's best to enable
- * MBEDTLS_SSL_MAX_FRAGMENT_LENGTH and reduce MBEDTLS_SSL_MAX_CONTENT_LEN. This
- * reduces both incoming and outgoing buffer sizes. However this is only
- * guaranteed if the other end of the connection also supports the TLS
- * max_fragment_len extension. Otherwise the connection may fail.
+ * Uncomment to set the maximum plaintext size of the outgoing I/O buffer
+ * independently of the incoming I/O buffer.
  */
 //#define MBEDTLS_SSL_OUT_CONTENT_LEN             16384
 
@@ -3235,5 +3446,3 @@
 #endif
 
 #endif /* MBEDTLS_CONFIG_H */
-#define MBEDTLS_PSA_CRYPTO_STORAGE_C
-#define MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
diff --git a/features/mbedtls/inc/mbedtls/ctr_drbg.h b/features/mbedtls/inc/mbedtls/ctr_drbg.h
index c91ca58b35..cc3df7b113 100644
--- a/features/mbedtls/inc/mbedtls/ctr_drbg.h
+++ b/features/mbedtls/inc/mbedtls/ctr_drbg.h
@@ -36,6 +36,12 @@
 #ifndef MBEDTLS_CTR_DRBG_H
 #define MBEDTLS_CTR_DRBG_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "aes.h"
 
 #if defined(MBEDTLS_THREADING_C)
@@ -239,18 +245,20 @@ int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
 /**
  * \brief              This function updates the state of the CTR_DRBG context.
  *
- * \note               If \p add_len is greater than
- *                     #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT, only the first
- *                     #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT Bytes are used.
- *                     The remaining Bytes are silently discarded.
- *
  * \param ctx          The CTR_DRBG context.
  * \param additional   The data to update the state with.
- * \param add_len      Length of \p additional data.
+ * \param add_len      Length of \p additional in bytes. This must be at
+ *                     most #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT.
  *
+ * \return             \c 0 on success.
+ * \return             #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG if
+ *                     \p add_len is more than
+ *                     #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT.
+ * \return             An error from the underlying AES cipher on failure.
  */
-void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
-                      const unsigned char *additional, size_t add_len );
+int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
+                                 const unsigned char *additional,
+                                 size_t add_len );
 
 /**
  * \brief   This function updates a CTR_DRBG instance with additional
@@ -290,6 +298,35 @@ int mbedtls_ctr_drbg_random_with_add( void *p_rng,
 int mbedtls_ctr_drbg_random( void *p_rng,
                      unsigned char *output, size_t output_len );
 
+
+#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED    __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief              This function updates the state of the CTR_DRBG context.
+ *
+ * \deprecated         Superseded by mbedtls_ctr_drbg_update_ret()
+ *                     in 2.16.0.
+ *
+ * \note               If \p add_len is greater than
+ *                     #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT, only the first
+ *                     #MBEDTLS_CTR_DRBG_MAX_SEED_INPUT Bytes are used.
+ *                     The remaining Bytes are silently discarded.
+ *
+ * \param ctx          The CTR_DRBG context.
+ * \param additional   The data to update the state with.
+ * \param add_len      Length of \p additional data.
+ */
+MBEDTLS_DEPRECATED void mbedtls_ctr_drbg_update(
+    mbedtls_ctr_drbg_context *ctx,
+    const unsigned char *additional,
+    size_t add_len );
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+
 #if defined(MBEDTLS_FS_IO)
 /**
  * \brief               This function writes a seed file.
@@ -319,6 +356,8 @@ int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char
 int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );
 #endif /* MBEDTLS_FS_IO */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief               The CTR_DRBG checkup routine.
  *
@@ -327,6 +366,8 @@ int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char
  */
 int mbedtls_ctr_drbg_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 /* Internal functions (do not call directly) */
 int mbedtls_ctr_drbg_seed_entropy_len( mbedtls_ctr_drbg_context *,
                                int (*)(void *, unsigned char *, size_t), void *,
diff --git a/features/mbedtls/inc/mbedtls/debug.h b/features/mbedtls/inc/mbedtls/debug.h
index ef8db67ff1..736444bb76 100644
--- a/features/mbedtls/inc/mbedtls/debug.h
+++ b/features/mbedtls/inc/mbedtls/debug.h
@@ -65,6 +65,11 @@
     mbedtls_debug_print_crt( ssl, level, __FILE__, __LINE__, text, crt )
 #endif
 
+#if defined(MBEDTLS_ECDH_C)
+#define MBEDTLS_SSL_DEBUG_ECDH( level, ecdh, attr )               \
+    mbedtls_debug_printf_ecdh( ssl, level, __FILE__, __LINE__, ecdh, attr )
+#endif
+
 #else /* MBEDTLS_DEBUG_C */
 
 #define MBEDTLS_SSL_DEBUG_MSG( level, args )            do { } while( 0 )
@@ -73,6 +78,7 @@
 #define MBEDTLS_SSL_DEBUG_MPI( level, text, X )         do { } while( 0 )
 #define MBEDTLS_SSL_DEBUG_ECP( level, text, X )         do { } while( 0 )
 #define MBEDTLS_SSL_DEBUG_CRT( level, text, crt )       do { } while( 0 )
+#define MBEDTLS_SSL_DEBUG_ECDH( level, ecdh, attr )     do { } while( 0 )
 
 #endif /* MBEDTLS_DEBUG_C */
 
@@ -221,6 +227,36 @@ void mbedtls_debug_print_crt( const mbedtls_ssl_context *ssl, int level,
                       const char *text, const mbedtls_x509_crt *crt );
 #endif
 
+#if defined(MBEDTLS_ECDH_C)
+typedef enum
+{
+    MBEDTLS_DEBUG_ECDH_Q,
+    MBEDTLS_DEBUG_ECDH_QP,
+    MBEDTLS_DEBUG_ECDH_Z,
+} mbedtls_debug_ecdh_attr;
+
+/**
+ * \brief   Print a field of the ECDH structure in the SSL context to the debug
+ *          output. This function is always used through the
+ *          MBEDTLS_SSL_DEBUG_ECDH() macro, which supplies the ssl context, file
+ *          and line number parameters.
+ *
+ * \param ssl       SSL context
+ * \param level     error level of the debug message
+ * \param file      file the error has occurred in
+ * \param line      line number the error has occurred in
+ * \param ecdh      the ECDH context
+ * \param attr      the identifier of the attribute being output
+ *
+ * \attention       This function is intended for INTERNAL usage within the
+ *                  library only.
+ */
+void mbedtls_debug_printf_ecdh( const mbedtls_ssl_context *ssl, int level,
+                                const char *file, int line,
+                                const mbedtls_ecdh_context *ecdh,
+                                mbedtls_debug_ecdh_attr attr );
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/des.h b/features/mbedtls/inc/mbedtls/des.h
index d62042d14e..54e6b7894b 100644
--- a/features/mbedtls/inc/mbedtls/des.h
+++ b/features/mbedtls/inc/mbedtls/des.h
@@ -338,6 +338,8 @@ int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
 void mbedtls_des_setkey( uint32_t SK[32],
                          const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -345,6 +347,8 @@ void mbedtls_des_setkey( uint32_t SK[32],
  */
 int mbedtls_des_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/dhm.h b/features/mbedtls/inc/mbedtls/dhm.h
index 8e2d0208d4..2909f5fbc8 100644
--- a/features/mbedtls/inc/mbedtls/dhm.h
+++ b/features/mbedtls/inc/mbedtls/dhm.h
@@ -127,9 +127,15 @@ mbedtls_dhm_context;
 void mbedtls_dhm_init( mbedtls_dhm_context *ctx );
 
 /**
- * \brief          This function parses the ServerKeyExchange parameters.
+ * \brief          This function parses the DHM parameters in a
+ *                 TLS ServerKeyExchange handshake message
+ *                 (DHM modulus, generator, and public key).
  *
- * \param ctx      The DHM context.
+ * \note           In a TLS handshake, this is the how the client
+ *                 sets up its DHM context from the server's public
+ *                 DHM key material.
+ *
+ * \param ctx      The DHM context to use. This must be initialized.
  * \param p        On input, *p must be the start of the input buffer.
  *                 On output, *p is updated to point to the end of the data
  *                 that has been read. On success, this is the first byte
@@ -143,31 +149,37 @@ void mbedtls_dhm_init( mbedtls_dhm_context *ctx );
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
  */
 int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
-                     unsigned char **p,
-                     const unsigned char *end );
+                             unsigned char **p,
+                             const unsigned char *end );
 
 /**
- * \brief          This function sets up and writes the ServerKeyExchange
- *                 parameters.
+ * \brief          This function generates a DHM key pair and exports its
+ *                 public part together with the DHM parameters in the format
+ *                 used in a TLS ServerKeyExchange handshake message.
  *
- * \note           The destination buffer must be large enough to hold
- *                 the reduced binary presentation of the modulus, the generator
- *                 and the public key, each wrapped with a 2-byte length field.
- *                 It is the responsibility of the caller to ensure that enough
- *                 space is available. Refer to \c mbedtls_mpi_size to computing
- *                 the byte-size of an MPI.
- *
- * \note           This function assumes that \c ctx->P and \c ctx->G
- *                 have already been properly set. For that, use
+ * \note           This function assumes that the DHM parameters \c ctx->P
+ *                 and \c ctx->G have already been properly set. For that, use
  *                 mbedtls_dhm_set_group() below in conjunction with
  *                 mbedtls_mpi_read_binary() and mbedtls_mpi_read_string().
  *
- * \param ctx      The DHM context.
+ * \note           In a TLS handshake, this is the how the server generates
+ *                 and exports its DHM key material.
+ *
+ * \param ctx      The DHM context to use. This must be initialized
+ *                 and have the DHM parameters set. It may or may not
+ *                 already have imported the peer's public key.
  * \param x_size   The private key size in Bytes.
- * \param olen     The number of characters written.
- * \param output   The destination buffer.
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param olen     The address at which to store the number of Bytes
+ *                 written on success. This must not be \c NULL.
+ * \param output   The destination buffer. This must be a writable buffer of
+ *                 sufficient size to hold the reduced binary presentation of
+ *                 the modulus, the generator and the public key, each wrapped
+ *                 with a 2-byte length field. It is the responsibility of the
+ *                 caller to ensure that enough space is available. Refer to
+ *                 mbedtls_mpi_size() to computing the byte-size of an MPI.
+ * \param f_rng    The RNG function. Must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng doesn't need a context parameter.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -180,12 +192,14 @@ int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
 /**
  * \brief          This function sets the prime modulus and generator.
  *
- * \note           This function can be used to set \p P, \p G
+ * \note           This function can be used to set \c ctx->P, \c ctx->G
  *                 in preparation for mbedtls_dhm_make_params().
  *
- * \param ctx      The DHM context.
- * \param P        The MPI holding the DHM prime modulus.
- * \param G        The MPI holding the DHM generator.
+ * \param ctx      The DHM context to configure. This must be initialized.
+ * \param P        The MPI holding the DHM prime modulus. This must be
+ *                 an initialized MPI.
+ * \param G        The MPI holding the DHM generator. This must be an
+ *                 initialized MPI.
  *
  * \return         \c 0 if successful.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -195,11 +209,17 @@ int mbedtls_dhm_set_group( mbedtls_dhm_context *ctx,
                            const mbedtls_mpi *G );
 
 /**
- * \brief          This function imports the public value of the peer, G^Y.
+ * \brief          This function imports the raw public value of the peer.
  *
- * \param ctx      The DHM context.
- * \param input    The input buffer containing the G^Y value of the peer.
- * \param ilen     The size of the input buffer.
+ * \note           In a TLS handshake, this is the how the server imports
+ *                 the Client's public DHM key.
+ *
+ * \param ctx      The DHM context to use. This must be initialized and have
+ *                 its DHM parameters set, e.g. via mbedtls_dhm_set_group().
+ *                 It may or may not already have generated its own private key.
+ * \param input    The input buffer containing the \c G^Y value of the peer.
+ *                 This must be a readable buffer of size \p ilen Bytes.
+ * \param ilen     The size of the input buffer \p input in Bytes.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -208,21 +228,25 @@ int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
                      const unsigned char *input, size_t ilen );
 
 /**
- * \brief          This function creates its own private key, \c X, and
- *                 exports \c G^X.
+ * \brief          This function creates a DHM key pair and exports
+ *                 the raw public key in big-endian format.
  *
  * \note           The destination buffer is always fully written
  *                 so as to contain a big-endian representation of G^X mod P.
- *                 If it is larger than ctx->len, it is padded accordingly
+ *                 If it is larger than \c ctx->len, it is padded accordingly
  *                 with zero-bytes at the beginning.
  *
- * \param ctx      The DHM context.
+ * \param ctx      The DHM context to use. This must be initialized and
+ *                 have the DHM parameters set. It may or may not already
+ *                 have imported the peer's public key.
  * \param x_size   The private key size in Bytes.
- * \param output   The destination buffer.
- * \param olen     The length of the destination buffer. Must be at least
- *                  equal to ctx->len (the size of \c P).
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param output   The destination buffer. This must be a writable buffer of
+ *                 size \p olen Bytes.
+ * \param olen     The length of the destination buffer. This must be at least
+ *                 equal to `ctx->len` (the size of \c P).
+ * \param f_rng    The RNG function. This must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL
+ *                 if \p f_rng doesn't need a context argument.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -233,22 +257,27 @@ int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
                      void *p_rng );
 
 /**
- * \brief               This function derives and exports the shared secret
- *                      \c (G^Y)^X mod \c P.
+ * \brief          This function derives and exports the shared secret
+ *                 \c (G^Y)^X mod \c P.
  *
- * \note                If \p f_rng is not NULL, it is used to blind the input as
- *                      a countermeasure against timing attacks. Blinding is used
- *                      only if our private key \c X is re-used, and not used
- *                      otherwise. We recommend always passing a non-NULL
- *                      \p f_rng argument.
+ * \note           If \p f_rng is not \c NULL, it is used to blind the input as
+ *                 a countermeasure against timing attacks. Blinding is used
+ *                 only if our private key \c X is re-used, and not used
+ *                 otherwise. We recommend always passing a non-NULL
+ *                 \p f_rng argument.
  *
- * \param ctx           The DHM context.
- * \param output        The destination buffer.
- * \param output_size   The size of the destination buffer. Must be at least
- *                      the size of ctx->len (the size of \c P).
+ * \param ctx           The DHM context to use. This must be initialized
+ *                      and have its own private key generated and the peer's
+ *                      public key imported.
+ * \param output        The buffer to write the generated shared key to. This
+ *                      must be a writable buffer of size \p output_size Bytes.
+ * \param output_size   The size of the destination buffer. This must be at
+ *                      least the size of \c ctx->len (the size of \c P).
  * \param olen          On exit, holds the actual number of Bytes written.
- * \param f_rng         The RNG function, for blinding purposes.
- * \param p_rng         The RNG context.
+ * \param f_rng         The RNG function, for blinding purposes. This may
+ *                      b \c NULL if blinding isn't needed.
+ * \param p_rng         The RNG context. This may be \c NULL if \p f_rng
+ *                      doesn't need a context argument.
  *
  * \return              \c 0 on success.
  * \return              An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -259,9 +288,12 @@ int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
                      void *p_rng );
 
 /**
- * \brief          This function frees and clears the components of a DHM context.
+ * \brief          This function frees and clears the components
+ *                 of a DHM context.
  *
- * \param ctx      The DHM context to free and clear.
+ * \param ctx      The DHM context to free and clear. This may be \c NULL,
+ *                 in which case this function is a no-op. If it is not \c NULL,
+ *                 it must point to an initialized DHM context.
  */
 void mbedtls_dhm_free( mbedtls_dhm_context *ctx );
 
@@ -270,17 +302,19 @@ void mbedtls_dhm_free( mbedtls_dhm_context *ctx );
 /**
  * \brief             This function parses DHM parameters in PEM or DER format.
  *
- * \param dhm         The DHM context to initialize.
- * \param dhmin       The input buffer.
- * \param dhminlen    The size of the buffer, including the terminating null
- *                    Byte for PEM data.
+ * \param dhm         The DHM context to import the DHM parameters into.
+ *                    This must be initialized.
+ * \param dhmin       The input buffer. This must be a readable buffer of
+ *                    length \p dhminlen Bytes.
+ * \param dhminlen    The size of the input buffer \p dhmin, including the
+ *                    terminating \c NULL Byte for PEM data.
  *
  * \return            \c 0 on success.
- * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error code
- *                    error code on failure.
+ * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error
+ *                    code on failure.
  */
 int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
-                   size_t dhminlen );
+                           size_t dhminlen );
 
 #if defined(MBEDTLS_FS_IO)
 /** \ingroup x509_module */
@@ -288,16 +322,20 @@ int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
  * \brief          This function loads and parses DHM parameters from a file.
  *
  * \param dhm      The DHM context to load the parameters to.
+ *                 This must be initialized.
  * \param path     The filename to read the DHM parameters from.
+ *                 This must not be \c NULL.
  *
  * \return         \c 0 on success.
- * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error code
- *                    error code on failure.
+ * \return         An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX
+ *                 error code on failure.
  */
 int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path );
 #endif /* MBEDTLS_FS_IO */
 #endif /* MBEDTLS_ASN1_PARSE_C */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The DMH checkup routine.
  *
@@ -306,6 +344,7 @@ int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path );
  */
 int mbedtls_dhm_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
 #ifdef __cplusplus
 }
 #endif
@@ -353,15 +392,6 @@ int mbedtls_dhm_self_test( int verbose );
 
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 
-#if defined(MBEDTLS_DEPRECATED_WARNING)
-#define MBEDTLS_DEPRECATED __attribute__((deprecated))
-MBEDTLS_DEPRECATED typedef char const * mbedtls_deprecated_constant_t;
-#define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL )       \
-    ( (mbedtls_deprecated_constant_t) ( VAL ) )
-#else
-#define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL
-#endif /* ! MBEDTLS_DEPRECATED_WARNING */
-
 /**
  * \warning The origin of the primes in RFC 5114 is not documented and
  *          their use therefore constitutes a security risk!
diff --git a/features/mbedtls/inc/mbedtls/ecdh.h b/features/mbedtls/inc/mbedtls/ecdh.h
index 27f2ffc6aa..4479a1d46f 100644
--- a/features/mbedtls/inc/mbedtls/ecdh.h
+++ b/features/mbedtls/inc/mbedtls/ecdh.h
@@ -34,8 +34,26 @@
 #ifndef MBEDTLS_ECDH_H
 #define MBEDTLS_ECDH_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "ecp.h"
 
+/*
+ * Use a backward compatible ECDH context.
+ *
+ * This flag is always enabled for now and future versions might add a
+ * configuration option that conditionally undefines this flag.
+ * The configuration option in question may have a different name.
+ *
+ * Features undefining this flag, must have a warning in their description in
+ * config.h stating that the feature breaks backward compatibility.
+ */
+#define MBEDTLS_ECDH_LEGACY_CONTEXT
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -49,6 +67,39 @@ typedef enum
     MBEDTLS_ECDH_THEIRS, /**< The key of the peer. */
 } mbedtls_ecdh_side;
 
+#if !defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+/**
+ * Defines the ECDH implementation used.
+ *
+ * Later versions of the library may add new variants, therefore users should
+ * not make any assumptions about them.
+ */
+typedef enum
+{
+    MBEDTLS_ECDH_VARIANT_NONE = 0,   /*!< Implementation not defined. */
+    MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0,/*!< The default Mbed TLS implementation */
+} mbedtls_ecdh_variant;
+
+/**
+ * The context used by the default ECDH implementation.
+ *
+ * Later versions might change the structure of this context, therefore users
+ * should not make any assumptions about the structure of
+ * mbedtls_ecdh_context_mbed.
+ */
+typedef struct mbedtls_ecdh_context_mbed
+{
+    mbedtls_ecp_group grp;   /*!< The elliptic curve used. */
+    mbedtls_mpi d;           /*!< The private key. */
+    mbedtls_ecp_point Q;     /*!< The public key. */
+    mbedtls_ecp_point Qp;    /*!< The value of the public key of the peer. */
+    mbedtls_mpi z;           /*!< The shared secret. */
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    mbedtls_ecp_restart_ctx rs; /*!< The restart context for EC computations. */
+#endif
+} mbedtls_ecdh_context_mbed;
+#endif
+
 /**
  *
  * \warning         Performing multiple operations concurrently on the same
@@ -58,6 +109,7 @@ typedef enum
  */
 typedef struct mbedtls_ecdh_context
 {
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
     mbedtls_ecp_group grp;   /*!< The elliptic curve used. */
     mbedtls_mpi d;           /*!< The private key. */
     mbedtls_ecp_point Q;     /*!< The public key. */
@@ -70,7 +122,26 @@ typedef struct mbedtls_ecdh_context
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     int restart_enabled;        /*!< The flag for restartable mode. */
     mbedtls_ecp_restart_ctx rs; /*!< The restart context for EC computations. */
-#endif
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+#else
+    uint8_t point_format;       /*!< The format of point export in TLS messages
+                                  as defined in RFC 4492. */
+    mbedtls_ecp_group_id grp_id;/*!< The elliptic curve used. */
+    mbedtls_ecdh_variant var;   /*!< The ECDH implementation/structure used. */
+    union
+    {
+        mbedtls_ecdh_context_mbed   mbed_ecdh;
+    } ctx;                      /*!< Implementation-specific context. The
+                                  context in use is specified by the \c var
+                                  field. */
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    uint8_t restart_enabled;    /*!< The flag for restartable mode. Functions of
+                                  an alternative implementation not supporting
+                                  restartable mode must return
+                                  MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED error
+                                  if this flag is set. */
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+#endif /* MBEDTLS_ECDH_LEGACY_CONTEXT */
 }
 mbedtls_ecdh_context;
 
@@ -84,11 +155,16 @@ mbedtls_ecdh_context;
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to use. This must be initialized and have
+ *                  domain parameters loaded, for example through
+ *                  mbedtls_ecp_load() or mbedtls_ecp_tls_read_group().
  * \param d         The destination MPI (private key).
+ *                  This must be initialized.
  * \param Q         The destination point (public key).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX or
@@ -111,12 +187,22 @@ int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp
  *                  countermeasures against side-channel attacks.
  *                  For more information, see mbedtls_ecp_mul().
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to use. This must be initialized and have
+ *                  domain parameters loaded, for example through
+ *                  mbedtls_ecp_load() or mbedtls_ecp_tls_read_group().
  * \param z         The destination MPI (shared secret).
+ *                  This must be initialized.
  * \param Q         The public key from another party.
+ *                  This must be initialized.
  * \param d         Our secret exponent (private key).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results during the ECP computations is
+ *                  not needed (discouraged). See the documentation of
+ *                  mbedtls_ecp_mul() for more.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't need a
+ *                  context argument.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX or
@@ -130,36 +216,57 @@ int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
 /**
  * \brief           This function initializes an ECDH context.
  *
- * \param ctx       The ECDH context to initialize.
+ * \param ctx       The ECDH context to initialize. This must not be \c NULL.
  */
 void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx );
 
 /**
- * \brief           This function frees a context.
+ * \brief           This function sets up the ECDH context with the information
+ *                  given.
  *
- * \param ctx       The context to free.
- */
-void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx );
-
-/**
- * \brief           This function generates a public key and a TLS
- *                  ServerKeyExchange payload.
+ *                  This function should be called after mbedtls_ecdh_init() but
+ *                  before mbedtls_ecdh_make_params(). There is no need to call
+ *                  this function before mbedtls_ecdh_read_params().
  *
  *                  This is the first function used by a TLS server for ECDHE
  *                  ciphersuites.
  *
- * \note            This function assumes that the ECP group (grp) of the
- *                  \p ctx context has already been properly set,
- *                  for example, using mbedtls_ecp_group_load().
+ * \param ctx       The ECDH context to set up. This must be initialized.
+ * \param grp_id    The group id of the group to set up the context for.
+ *
+ * \return          \c 0 on success.
+ */
+int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx,
+                        mbedtls_ecp_group_id grp_id );
+
+/**
+ * \brief           This function frees a context.
+ *
+ * \param ctx       The context to free. This may be \c NULL, in which
+ *                  case this function does nothing. If it is not \c NULL,
+ *                  it must point to an initialized ECDH context.
+ */
+void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx );
+
+/**
+ * \brief           This function generates an EC key pair and exports its
+ *                  in the format used in a TLS ServerKeyExchange handshake
+ *                  message.
+ *
+ *                  This is the second function used by a TLS server for ECDHE
+ *                  ciphersuites. (It is called after mbedtls_ecdh_setup().)
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param olen      The number of characters written.
- * \param buf       The destination buffer.
- * \param blen      The length of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and bound to a group, for example via mbedtls_ecdh_setup().
+ * \param olen      The address at which to store the number of Bytes written.
+ * \param buf       The destination buffer. This must be a writable buffer of
+ *                  length \p blen Bytes.
+ * \param blen      The length of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -172,24 +279,32 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
                       void *p_rng );
 
 /**
- * \brief           This function parses and processes a TLS ServerKeyExhange
- *                  payload.
+ * \brief           This function parses the ECDHE parameters in a
+ *                  TLS ServerKeyExchange handshake message.
  *
- *                  This is the first function used by a TLS client for ECDHE
- *                  ciphersuites.
+ * \note            In a TLS handshake, this is the how the client
+ *                  sets up its ECDHE context from the server's public
+ *                  ECDHE key material.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param buf       The pointer to the start of the input buffer.
- * \param end       The address for one Byte past the end of the buffer.
+ * \param ctx       The ECDHE context to use. This must be initialized.
+ * \param buf       On input, \c *buf must be the start of the input buffer.
+ *                  On output, \c *buf is updated to point to the end of the
+ *                  data that has been read. On success, this is the first byte
+ *                  past the end of the ServerKeyExchange parameters.
+ *                  On error, this is the point at which an error has been
+ *                  detected, which is usually not useful except to debug
+ *                  failures.
+ * \param end       The end of the input buffer.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX error code on failure.
  *
  */
 int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
-                      const unsigned char **buf, const unsigned char *end );
+                              const unsigned char **buf,
+                              const unsigned char *end );
 
 /**
  * \brief           This function sets up an ECDH context from an EC key.
@@ -200,33 +315,40 @@ int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context to set up.
- * \param key       The EC key to use.
- * \param side      Defines the source of the key: 1: Our key, or
- *                  0: The key of the peer.
+ * \param ctx       The ECDH context to set up. This must be initialized.
+ * \param key       The EC key to use. This must be initialized.
+ * \param side      Defines the source of the key. Possible values are:
+ *                  - #MBEDTLS_ECDH_OURS: The key is ours.
+ *                  - #MBEDTLS_ECDH_THEIRS: The key is that of the peer.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX error code on failure.
  *
  */
-int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key,
-                     mbedtls_ecdh_side side );
+int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,
+                             const mbedtls_ecp_keypair *key,
+                             mbedtls_ecdh_side side );
 
 /**
- * \brief           This function generates a public key and a TLS
- *                  ClientKeyExchange payload.
+ * \brief           This function generates a public key and exports it
+ *                  as a TLS ClientKeyExchange payload.
  *
  *                  This is the second function used by a TLS client for ECDH(E)
  *                  ciphersuites.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param olen      The number of Bytes written.
- * \param buf       The destination buffer.
- * \param blen      The size of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and bound to a group, the latter usually by
+ *                  mbedtls_ecdh_read_params().
+ * \param olen      The address at which to store the number of Bytes written.
+ *                  This must not be \c NULL.
+ * \param buf       The destination buffer. This must be a writable buffer
+ *                  of length \p blen Bytes.
+ * \param blen      The size of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -239,23 +361,26 @@ int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
                       void *p_rng );
 
 /**
- * \brief       This function parses and processes a TLS ClientKeyExchange
- *              payload.
+ * \brief       This function parses and processes the ECDHE payload of a
+ *              TLS ClientKeyExchange message.
  *
- *              This is the second function used by a TLS server for ECDH(E)
- *              ciphersuites.
+ *              This is the third function used by a TLS server for ECDH(E)
+ *              ciphersuites. (It is called after mbedtls_ecdh_setup() and
+ *              mbedtls_ecdh_make_params().)
  *
  * \see         ecp.h
  *
- * \param ctx   The ECDH context.
- * \param buf   The start of the input buffer.
- * \param blen  The length of the input buffer.
+ * \param ctx   The ECDH context to use. This must be initialized
+ *              and bound to a group, for example via mbedtls_ecdh_setup().
+ * \param buf   The pointer to the ClientKeyExchange payload. This must
+ *              be a readable buffer of length \p blen Bytes.
+ * \param blen  The length of the input buffer \p buf in Bytes.
  *
  * \return      \c 0 on success.
  * \return      An \c MBEDTLS_ERR_ECP_XXX error code on failure.
  */
 int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
-                      const unsigned char *buf, size_t blen );
+                              const unsigned char *buf, size_t blen );
 
 /**
  * \brief           This function derives and exports the shared secret.
@@ -268,13 +393,19 @@ int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
  *                  For more information, see mbedtls_ecp_mul().
  *
  * \see             ecp.h
- *
- * \param ctx       The ECDH context.
- * \param olen      The number of Bytes written.
- * \param buf       The destination buffer.
- * \param blen      The length of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and have its own private key generated and the peer's
+ *                  public key imported.
+ * \param olen      The address at which to store the total number of
+ *                  Bytes written on success. This must not be \c NULL.
+ * \param buf       The buffer to write the generated shared key to. This
+ *                  must be a writable buffer of size \p blen Bytes.
+ * \param blen      The length of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function, for blinding purposes. This may
+ *                  b \c NULL if blinding isn't needed.
+ * \param p_rng     The RNG context. This may be \c NULL if \p f_rng
+ *                  doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -297,7 +428,7 @@ int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
  *                  computations once enabled, except by free-ing the context,
  *                  which cancels possible in-progress operations.
  *
- * \param ctx       The ECDH context.
+ * \param ctx       The ECDH context to use. This must be initialized.
  */
 void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/features/mbedtls/inc/mbedtls/ecdsa.h b/features/mbedtls/inc/mbedtls/ecdsa.h
index 5245c6ee36..2943945518 100644
--- a/features/mbedtls/inc/mbedtls/ecdsa.h
+++ b/features/mbedtls/inc/mbedtls/ecdsa.h
@@ -32,6 +32,12 @@
 #ifndef MBEDTLS_ECDSA_H
 #define MBEDTLS_ECDSA_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "ecp.h"
 #include "md.h"
 
@@ -123,7 +129,8 @@ typedef void mbedtls_ecdsa_restart_ctx;
  * \brief           This function computes the ECDSA signature of a
  *                  previously-hashed message.
  *
- * \note            The deterministic version is usually preferred.
+ * \note            The deterministic version implemented in
+ *                  mbedtls_ecdsa_sign_det() is usually preferred.
  *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated
@@ -133,14 +140,22 @@ typedef void mbedtls_ecdsa_restart_ctx;
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param r         The first output integer.
- * \param s         The second output integer.
- * \param d         The private signing key.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The context for the elliptic curve to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param r         The MPI context in which to store the first part
+ *                  the signature. This must be initialized.
+ * \param s         The MPI context in which to store the second part
+ *                  the signature. This must be initialized.
+ * \param d         The private signing key. This must be initialized.
+ * \param buf       The content to be signed. This is usually the hash of
+ *                  the original data to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng doesn't need a context parameter.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX
@@ -167,21 +182,29 @@ int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param r         The first output integer.
- * \param s         The second output integer.
- * \param d         The private signing key.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param md_alg    The MD algorithm used to hash the message.
+ * \param grp       The context for the elliptic curve to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param r         The MPI context in which to store the first part
+ *                  the signature. This must be initialized.
+ * \param s         The MPI context in which to store the second part
+ *                  the signature. This must be initialized.
+ * \param d         The private signing key. This must be initialized
+ *                  and setup, for example through mbedtls_ecp_gen_privkey().
+ * \param buf       The hashed content to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param md_alg    The hash algorithm used to hash the original data.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
  *                  error code on failure.
  */
-int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
-                    const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
-                    mbedtls_md_type_t md_alg );
+int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r,
+                            mbedtls_mpi *s, const mbedtls_mpi *d,
+                            const unsigned char *buf, size_t blen,
+                            mbedtls_md_type_t md_alg );
 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
 
 /**
@@ -196,12 +219,19 @@ int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param Q         The public key to use for verification.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param buf       The hashed content that was signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param Q         The public key to use for verification. This must be
+ *                  initialized and setup.
  * \param r         The first integer of the signature.
+ *                  This must be initialized.
  * \param s         The second integer of the signature.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the signature
@@ -210,8 +240,9 @@ int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi
  *                  error code on failure for any other reason.
  */
 int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
-                  const unsigned char *buf, size_t blen,
-                  const mbedtls_ecp_point *Q, const mbedtls_mpi *r, const mbedtls_mpi *s);
+                          const unsigned char *buf, size_t blen,
+                          const mbedtls_ecp_point *Q, const mbedtls_mpi *r,
+                          const mbedtls_mpi *s);
 
 /**
  * \brief           This function computes the ECDSA signature and writes it
@@ -228,11 +259,6 @@ int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
  *                  of the Digital Signature Algorithm (DSA) and Elliptic
  *                  Curve Digital Signature Algorithm (ECDSA)</em>.
  *
- * \note            The \p sig buffer must be at least twice as large as the
- *                  size of the curve used, plus 9. For example, 73 Bytes if
- *                  a 256-bit curve is used. A buffer length of
- *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
- *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated as
  *                  defined in <em>Standards for Efficient Cryptography Group
@@ -241,20 +267,32 @@ int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param f_rng     The RNG function. This must not be \c NULL if
+ *                  #MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
+ *                  it is unused and may be set to \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't use a context.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
  *                  \c MBEDTLS_ERR_ASN1_XXX error code on failure.
  */
-int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t md_alg,
+int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
+                                   mbedtls_md_type_t md_alg,
                            const unsigned char *hash, size_t hlen,
                            unsigned char *sig, size_t *slen,
                            int (*f_rng)(void *, unsigned char *, size_t),
@@ -270,15 +308,28 @@ int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param ctx       The ECDSA context.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
- * \param rs_ctx    The restart context (NULL disables restart).
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param f_rng     The RNG function. This must not be \c NULL if
+ *                  #MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
+ *                  it is unused and may be set to \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't use a context.
+ * \param rs_ctx    The restart context to use. This may be \c NULL to disable
+ *                  restarting. If it is not \c NULL, it must point to an
+ *                  initialized restart context.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -314,11 +365,6 @@ int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
  * \warning         It is not thread-safe to use the same context in
  *                  multiple threads.
  *
- * \note            The \p sig buffer must be at least twice as large as the
- *                  size of the curve used, plus 9. For example, 73 Bytes if a
- *                  256-bit curve is used. A buffer length of
- *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
- *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated as
  *                  defined in <em>Standards for Efficient Cryptography Group
@@ -330,12 +376,20 @@ int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
  * \deprecated      Superseded by mbedtls_ecdsa_write_signature() in
  *                  Mbed TLS version 2.0 and later.
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param md_alg    The MD algorithm used to hash the message.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param md_alg    The message digest that was used to hash the message.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
@@ -360,11 +414,14 @@ int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The size of the hash.
- * \param sig       The signature to read and verify.
- * \param slen      The size of \p sig.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and public key bound to it.
+ * \param hash      The message hash that was signed. This must be a readable
+ *                  buffer of length \p size Bytes.
+ * \param hlen      The size of the hash \p hash.
+ * \param sig       The signature to read and verify. This must be a readable
+ *                  buffer of length \p slen Bytes.
+ * \param slen      The size of \p sig in Bytes.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
@@ -387,12 +444,17 @@ int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The size of the hash.
- * \param sig       The signature to read and verify.
- * \param slen      The size of \p sig.
- * \param rs_ctx    The restart context (NULL disables restart).
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and public key bound to it.
+ * \param hash      The message hash that was signed. This must be a readable
+ *                  buffer of length \p size Bytes.
+ * \param hlen      The size of the hash \p hash.
+ * \param sig       The signature to read and verify. This must be a readable
+ *                  buffer of length \p slen Bytes.
+ * \param slen      The size of \p sig in Bytes.
+ * \param rs_ctx    The restart context to use. This may be \c NULL to disable
+ *                  restarting. If it is not \c NULL, it must point to an
+ *                  initialized restart context.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
@@ -414,10 +476,12 @@ int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
  * \see            ecp.h
  *
  * \param ctx      The ECDSA context to store the keypair in.
+ *                 This must be initialized.
  * \param gid      The elliptic curve to use. One of the various
  *                 \c MBEDTLS_ECP_DP_XXX macros depending on configuration.
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_ECP_XXX code on failure.
@@ -426,40 +490,55 @@ int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /**
- * \brief           This function sets an ECDSA context from an EC key pair.
+ * \brief           This function sets up an ECDSA context from an EC key pair.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context to set.
- * \param key       The EC key to use.
+ * \param ctx       The ECDSA context to setup. This must be initialized.
+ * \param key       The EC key to use. This must be initialized and hold
+ *                  a private-public key pair or a public key. In the former
+ *                  case, the ECDSA context may be used for signature creation
+ *                  and verification after this call. In the latter case, it
+ *                  may be used for signature verification.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX code on failure.
  */
-int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key );
+int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx,
+                                const mbedtls_ecp_keypair *key );
 
 /**
  * \brief           This function initializes an ECDSA context.
  *
  * \param ctx       The ECDSA context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx );
 
 /**
  * \brief           This function frees an ECDSA context.
  *
- * \param ctx       The ECDSA context to free.
+ * \param ctx       The ECDSA context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it
+ *                  is not \c NULL, it must be initialized.
  */
 void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 /**
- * \brief           Initialize a restart context
+ * \brief           Initialize a restart context.
+ *
+ * \param ctx       The restart context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx );
 
 /**
- * \brief           Free the components of a restart context
+ * \brief           Free the components of a restart context.
+ *
+ * \param ctx       The restart context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it
+ *                  is not \c NULL, it must be initialized.
  */
 void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/features/mbedtls/inc/mbedtls/ecjpake.h b/features/mbedtls/inc/mbedtls/ecjpake.h
index 59d12f080f..3d8d02ae64 100644
--- a/features/mbedtls/inc/mbedtls/ecjpake.h
+++ b/features/mbedtls/inc/mbedtls/ecjpake.h
@@ -40,6 +40,11 @@
  * The payloads are serialized in a way suitable for use in TLS, but could
  * also be use outside TLS.
  */
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
 
 #include "ecp.h"
 #include "md.h"
@@ -92,28 +97,33 @@ typedef struct mbedtls_ecjpake_context
 #endif /* MBEDTLS_ECJPAKE_ALT */
 
 /**
- * \brief           Initialize a context
- *                  (just makes it ready for setup() or free()).
+ * \brief           Initialize an ECJPAKE context.
  *
- * \param ctx       context to initialize
+ * \param ctx       The ECJPAKE context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx );
 
 /**
- * \brief           Set up a context for use
+ * \brief           Set up an ECJPAKE context for use.
  *
  * \note            Currently the only values for hash/curve allowed by the
- *                  standard are MBEDTLS_MD_SHA256/MBEDTLS_ECP_DP_SECP256R1.
+ *                  standard are #MBEDTLS_MD_SHA256/#MBEDTLS_ECP_DP_SECP256R1.
  *
- * \param ctx       context to set up
- * \param role      Our role: client or server
- * \param hash      hash function to use (MBEDTLS_MD_XXX)
- * \param curve     elliptic curve identifier (MBEDTLS_ECP_DP_XXX)
- * \param secret    pre-shared secret (passphrase)
- * \param len       length of the shared secret
+ * \param ctx       The ECJPAKE context to set up. This must be initialized.
+ * \param role      The role of the caller. This must be either
+ *                  #MBEDTLS_ECJPAKE_CLIENT or #MBEDTLS_ECJPAKE_SERVER.
+ * \param hash      The identifier of the hash function to use,
+ *                  for example #MBEDTLS_MD_SHA256.
+ * \param curve     The identifier of the elliptic curve to use,
+ *                  for example #MBEDTLS_ECP_DP_SECP256R1.
+ * \param secret    The pre-shared secret (passphrase). This must be
+ *                  a readable buffer of length \p len Bytes. It need
+ *                  only be valid for the duration of this call.
+ * \param len       The length of the pre-shared secret \p secret.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
                            mbedtls_ecjpake_role role,
@@ -123,29 +133,34 @@ int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
                            size_t len );
 
 /**
- * \brief           Check if a context is ready for use
+ * \brief           Check if an ECJPAKE context is ready for use.
  *
- * \param ctx       Context to check
+ * \param ctx       The ECJPAKE context to check. This must be
+ *                  initialized.
  *
- * \return          0 if the context is ready for use,
- *                  MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise
+ * \return          \c 0 if the context is ready for use.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise.
  */
 int mbedtls_ecjpake_check( const mbedtls_ecjpake_context *ctx );
 
 /**
  * \brief           Generate and write the first round message
  *                  (TLS: contents of the Client/ServerHello extension,
- *                  excluding extension type and length bytes)
+ *                  excluding extension type and length bytes).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be
+ *                  initialized and set up.
+ * \param buf       The buffer to write the contents to. This must be a
+ *                  writable buffer of length \p len Bytes.
+ * \param len       The length of \p buf in Bytes.
+ * \param olen      The address at which to store the total number
+ *                  of Bytes written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_write_round_one( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -155,14 +170,16 @@ int mbedtls_ecjpake_write_round_one( mbedtls_ecjpake_context *ctx,
 /**
  * \brief           Read and process the first round message
  *                  (TLS: contents of the Client/ServerHello extension,
- *                  excluding extension type and length bytes)
+ *                  excluding extension type and length bytes).
  *
- * \param ctx       Context to use
- * \param buf       Pointer to extension contents
- * \param len       Extension length
+ * \param ctx       The ECJPAKE context to use. This must be initialized
+ *                  and set up.
+ * \param buf       The buffer holding the first round message. This must
+ *                  be a readable buffer of length \p len Bytes.
+ * \param len       The length in Bytes of \p buf.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_read_round_one( mbedtls_ecjpake_context *ctx,
                                     const unsigned char *buf,
@@ -170,17 +187,21 @@ int mbedtls_ecjpake_read_round_one( mbedtls_ecjpake_context *ctx,
 
 /**
  * \brief           Generate and write the second round message
- *                  (TLS: contents of the Client/ServerKeyExchange)
+ *                  (TLS: contents of the Client/ServerKeyExchange).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be initialized,
+ *                  set up, and already have performed round one.
+ * \param buf       The buffer to write the round two contents to.
+ *                  This must be a writable buffer of length \p len Bytes.
+ * \param len       The size of \p buf in Bytes.
+ * \param olen      The address at which to store the total number of Bytes
+ *                  written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_write_round_two( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -189,14 +210,16 @@ int mbedtls_ecjpake_write_round_two( mbedtls_ecjpake_context *ctx,
 
 /**
  * \brief           Read and process the second round message
- *                  (TLS: contents of the Client/ServerKeyExchange)
+ *                  (TLS: contents of the Client/ServerKeyExchange).
  *
- * \param ctx       Context to use
- * \param buf       Pointer to the message
- * \param len       Message length
+ * \param ctx       The ECJPAKE context to use. This must be initialized
+ *                  and set up and already have performed round one.
+ * \param buf       The buffer holding the second round message. This must
+ *                  be a readable buffer of length \p len Bytes.
+ * \param len       The length in Bytes of \p buf.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_read_round_two( mbedtls_ecjpake_context *ctx,
                                     const unsigned char *buf,
@@ -204,17 +227,21 @@ int mbedtls_ecjpake_read_round_two( mbedtls_ecjpake_context *ctx,
 
 /**
  * \brief           Derive the shared secret
- *                  (TLS: Pre-Master Secret)
+ *                  (TLS: Pre-Master Secret).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be initialized,
+ *                  set up and have performed both round one and two.
+ * \param buf       The buffer to write the derived secret to. This must
+ *                  be a writable buffer of length \p len Bytes.
+ * \param len       The length of \p buf in Bytes.
+ * \param olen      The address at which to store the total number of Bytes
+ *                  written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_derive_secret( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -222,14 +249,15 @@ int mbedtls_ecjpake_derive_secret( mbedtls_ecjpake_context *ctx,
                             void *p_rng );
 
 /**
- * \brief           Free a context's content
+ * \brief           This clears an ECJPAKE context and frees any
+ *                  embedded data structure.
  *
- * \param ctx       context to free
+ * \param ctx       The ECJPAKE context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it is not
+ *                  \c NULL, it must point to an initialized ECJPAKE context.
  */
 void mbedtls_ecjpake_free( mbedtls_ecjpake_context *ctx );
 
-
-
 #if defined(MBEDTLS_SELF_TEST)
 
 /**
diff --git a/features/mbedtls/inc/mbedtls/ecp.h b/features/mbedtls/inc/mbedtls/ecp.h
index 2fb1af49a2..24017780d4 100644
--- a/features/mbedtls/inc/mbedtls/ecp.h
+++ b/features/mbedtls/inc/mbedtls/ecp.h
@@ -36,6 +36,12 @@
 #ifndef MBEDTLS_ECP_H
 #define MBEDTLS_ECP_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "bignum.h"
 
 /*
@@ -159,6 +165,10 @@ mbedtls_ecp_point;
  * additions or subtractions. Therefore, it is only an approximative modular
  * reduction. It must return 0 on success and non-zero on failure.
  *
+ * \note        Alternative implementations must keep the group IDs distinct. If
+ *              two group structures have the same ID, then they must be
+ *              identical.
+ *
  */
 typedef struct mbedtls_ecp_group
 {
@@ -185,6 +195,68 @@ typedef struct mbedtls_ecp_group
 }
 mbedtls_ecp_group;
 
+/**
+ * \name SECTION: Module settings
+ *
+ * The configuration options you can set for this module are in this section.
+ * Either change them in config.h, or define them using the compiler command line.
+ * \{
+ */
+
+#if !defined(MBEDTLS_ECP_MAX_BITS)
+/**
+ * The maximum size of the groups, that is, of \c N and \c P.
+ */
+#define MBEDTLS_ECP_MAX_BITS     521   /**< The maximum size of groups, in bits. */
+#endif
+
+#define MBEDTLS_ECP_MAX_BYTES    ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )
+#define MBEDTLS_ECP_MAX_PT_LEN   ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 )
+
+#if !defined(MBEDTLS_ECP_WINDOW_SIZE)
+/*
+ * Maximum "window" size used for point multiplication.
+ * Default: 6.
+ * Minimum value: 2. Maximum value: 7.
+ *
+ * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) )
+ * points used for point multiplication. This value is directly tied to EC
+ * peak memory usage, so decreasing it by one should roughly cut memory usage
+ * by two (if large curves are in use).
+ *
+ * Reduction in size may reduce speed, but larger curves are impacted first.
+ * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1):
+ *      w-size:     6       5       4       3       2
+ *      521       145     141     135     120      97
+ *      384       214     209     198     177     146
+ *      256       320     320     303     262     226
+ *      224       475     475     453     398     342
+ *      192       640     640     633     587     476
+ */
+#define MBEDTLS_ECP_WINDOW_SIZE    6   /**< The maximum window size used. */
+#endif /* MBEDTLS_ECP_WINDOW_SIZE */
+
+#if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM)
+/*
+ * Trade memory for speed on fixed-point multiplication.
+ *
+ * This speeds up repeated multiplication of the generator (that is, the
+ * multiplication in ECDSA signatures, and half of the multiplications in
+ * ECDSA verification and ECDHE) by a factor roughly 3 to 4.
+ *
+ * The cost is increasing EC peak memory usage by a factor roughly 2.
+ *
+ * Change this value to 0 to reduce peak memory usage.
+ */
+#define MBEDTLS_ECP_FIXED_POINT_OPTIM  1   /**< Enable fixed-point speed-up. */
+#endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */
+
+/* \} name SECTION: Module settings */
+
+#else  /* MBEDTLS_ECP_ALT */
+#include "ecp_alt.h"
+#endif /* MBEDTLS_ECP_ALT */
+
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 
 /**
@@ -249,68 +321,6 @@ typedef void mbedtls_ecp_restart_ctx;
 
 #endif /* MBEDTLS_ECP_RESTARTABLE */
 
-/**
- * \name SECTION: Module settings
- *
- * The configuration options you can set for this module are in this section.
- * Either change them in config.h, or define them using the compiler command line.
- * \{
- */
-
-#if !defined(MBEDTLS_ECP_MAX_BITS)
-/**
- * The maximum size of the groups, that is, of \c N and \c P.
- */
-#define MBEDTLS_ECP_MAX_BITS     521   /**< The maximum size of groups, in bits. */
-#endif
-
-#define MBEDTLS_ECP_MAX_BYTES    ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )
-#define MBEDTLS_ECP_MAX_PT_LEN   ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 )
-
-#if !defined(MBEDTLS_ECP_WINDOW_SIZE)
-/*
- * Maximum "window" size used for point multiplication.
- * Default: 6.
- * Minimum value: 2. Maximum value: 7.
- *
- * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) )
- * points used for point multiplication. This value is directly tied to EC
- * peak memory usage, so decreasing it by one should roughly cut memory usage
- * by two (if large curves are in use).
- *
- * Reduction in size may reduce speed, but larger curves are impacted first.
- * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1):
- *      w-size:     6       5       4       3       2
- *      521       145     141     135     120      97
- *      384       214     209     198     177     146
- *      256       320     320     303     262     226
- *      224       475     475     453     398     342
- *      192       640     640     633     587     476
- */
-#define MBEDTLS_ECP_WINDOW_SIZE    6   /**< The maximum window size used. */
-#endif /* MBEDTLS_ECP_WINDOW_SIZE */
-
-#if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM)
-/*
- * Trade memory for speed on fixed-point multiplication.
- *
- * This speeds up repeated multiplication of the generator (that is, the
- * multiplication in ECDSA signatures, and half of the multiplications in
- * ECDSA verification and ECDHE) by a factor roughly 3 to 4.
- *
- * The cost is increasing EC peak memory usage by a factor roughly 2.
- *
- * Change this value to 0 to reduce peak memory usage.
- */
-#define MBEDTLS_ECP_FIXED_POINT_OPTIM  1   /**< Enable fixed-point speed-up. */
-#endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */
-
-/* \} name SECTION: Module settings */
-
-#else  /* MBEDTLS_ECP_ALT */
-#include "ecp_alt.h"
-#endif /* MBEDTLS_ECP_ALT */
-
 /**
  * \brief    The ECP key-pair structure.
  *
@@ -493,24 +503,37 @@ void mbedtls_ecp_point_free( mbedtls_ecp_point *pt );
 
 /**
  * \brief           This function frees the components of an ECP group.
- * \param grp       The group to free.
+ *
+ * \param grp       The group to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized ECP group.
  */
 void mbedtls_ecp_group_free( mbedtls_ecp_group *grp );
 
 /**
  * \brief           This function frees the components of a key pair.
- * \param key       The key pair to free.
+ *
+ * \param key       The key pair to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized ECP key pair.
  */
 void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 /**
- * \brief           Initialize a restart context
+ * \brief           Initialize a restart context.
+ *
+ * \param ctx       The restart context to initialize. This must
+ *                  not be \c NULL.
  */
 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx );
 
 /**
- * \brief           Free the components of a restart context
+ * \brief           Free the components of a restart context.
+ *
+ * \param ctx       The restart context to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized restart context.
  */
 void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
@@ -519,11 +542,12 @@ void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx );
  * \brief           This function copies the contents of point \p Q into
  *                  point \p P.
  *
- * \param P         The destination point.
- * \param Q         The source point.
+ * \param P         The destination point. This must be initialized.
+ * \param Q         The source point. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code for other kinds of failure.
  */
 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
 
@@ -531,31 +555,35 @@ int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
  * \brief           This function copies the contents of group \p src into
  *                  group \p dst.
  *
- * \param dst       The destination group.
- * \param src       The source group.
+ * \param dst       The destination group. This must be initialized.
+ * \param src       The source group. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src );
+int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst,
+                            const mbedtls_ecp_group *src );
 
 /**
- * \brief           This function sets a point to zero.
+ * \brief           This function sets a point to the point at infinity.
  *
- * \param pt        The point to set.
+ * \param pt        The point to set. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt );
 
 /**
- * \brief           This function checks if a point is zero.
+ * \brief           This function checks if a point is the point at infinity.
  *
- * \param pt        The point to test.
+ * \param pt        The point to test. This must be initialized.
  *
  * \return          \c 1 if the point is zero.
  * \return          \c 0 if the point is non-zero.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt );
 
@@ -565,8 +593,8 @@ int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt );
  * \note            This assumes that the points are normalized. Otherwise,
  *                  they may compare as "not equal" even if they are.
  *
- * \param P         The first point to compare.
- * \param Q         The second point to compare.
+ * \param P         The first point to compare. This must be initialized.
+ * \param Q         The second point to compare. This must be initialized.
  *
  * \return          \c 0 if the points are equal.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the points are not equal.
@@ -578,7 +606,7 @@ int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P,
  * \brief           This function imports a non-zero point from two ASCII
  *                  strings.
  *
- * \param P         The destination point.
+ * \param P         The destination point. This must be initialized.
  * \param radix     The numeric base of the input.
  * \param x         The first affine coordinate, as a null-terminated string.
  * \param y         The second affine coordinate, as a null-terminated string.
@@ -593,15 +621,21 @@ int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix,
  * \brief           This function exports a point into unsigned binary data.
  *
  * \param grp       The group to which the point should belong.
- * \param P         The point to export.
- * \param format    The point format. Should be an \c MBEDTLS_ECP_PF_XXX macro.
- * \param olen      The length of the output.
- * \param buf       The output buffer.
- * \param buflen    The length of the output buffer.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param P         The point to export. This must be initialized.
+ * \param format    The point format. This must be either
+ *                  #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED.
+ * \param olen      The address at which to store the length of
+ *                  the output in Bytes. This must not be \c NULL.
+ * \param buf       The output buffer. This must be a writable buffer
+ *                  of length \p buflen Bytes.
+ * \param buflen    The length of the output buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA
- *                  or #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output buffer
+ *                  is too small to hold the point.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P,
                             int format, size_t *olen,
@@ -615,108 +649,158 @@ int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_
  *                  for that.
  *
  * \param grp       The group to which the point should belong.
- * \param P         The point to import.
- * \param buf       The input buffer.
- * \param ilen      The length of the input.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param P         The destination context to import the point to.
+ *                  This must be initialized.
+ * \param buf       The input buffer. This must be a readable buffer
+ *                  of length \p ilen Bytes.
+ * \param ilen      The length of the input buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format
  *                  is not implemented.
- *
  */
-int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, mbedtls_ecp_point *P,
-                           const unsigned char *buf, size_t ilen );
+int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp,
+                                   mbedtls_ecp_point *P,
+                                   const unsigned char *buf, size_t ilen );
 
 /**
  * \brief           This function imports a point from a TLS ECPoint record.
  *
- * \note            On function return, \p buf is updated to point to immediately
+ * \note            On function return, \p *buf is updated to point immediately
  *                  after the ECPoint record.
  *
- * \param grp       The ECP group used.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
  * \param pt        The destination point.
  * \param buf       The address of the pointer to the start of the input buffer.
  * \param len       The length of the buffer.
  *
  * \return          \c 0 on success.
- * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization failure.
+ * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization
+ *                  failure.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
  */
-int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                        const unsigned char **buf, size_t len );
+int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp,
+                                mbedtls_ecp_point *pt,
+                                const unsigned char **buf, size_t len );
 
 /**
- * \brief           This function exports a point as a TLS ECPoint record.
+ * \brief           This function exports a point as a TLS ECPoint record
+ *                  defined in RFC 4492, Section 5.4.
  *
- * \param grp       The ECP group used.
- * \param pt        The point format to export to. The point format is an
- *                  \c MBEDTLS_ECP_PF_XXX constant.
- * \param format    The export format.
- * \param olen      The length of the data written.
- * \param buf       The buffer to write to.
- * \param blen      The length of the buffer.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param pt        The point to be exported. This must be initialized.
+ * \param format    The point format to use. This must be either
+ *                  #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED.
+ * \param olen      The address at which to store the length in Bytes
+ *                  of the data written.
+ * \param buf       The target buffer. This must be a writable buffer of
+ *                  length \p blen Bytes.
+ * \param blen      The length of the target buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA or
- *                  #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the target buffer
+ *                  is too small to hold the exported point.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt,
-                         int format, size_t *olen,
-                         unsigned char *buf, size_t blen );
+int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp,
+                                 const mbedtls_ecp_point *pt,
+                                 int format, size_t *olen,
+                                 unsigned char *buf, size_t blen );
 
 /**
- * \brief           This function sets a group using standardized domain parameters.
+ * \brief           This function sets up an ECP group context
+ *                  from a standardized set of domain parameters.
  *
  * \note            The index should be a value of the NamedCurve enum,
  *                  as defined in <em>RFC-4492: Elliptic Curve Cryptography
  *                  (ECC) Cipher Suites for Transport Layer Security (TLS)</em>,
  *                  usually in the form of an \c MBEDTLS_ECP_DP_XXX macro.
  *
- * \param grp       The destination group.
+ * \param grp       The group context to setup. This must be initialized.
  * \param id        The identifier of the domain parameter set to load.
  *
- * \return          \c 0 on success,
- * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization failure.
- * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE for unkownn groups.
-
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p id doesn't
+ *                  correspond to a known group.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id );
 
 /**
- * \brief           This function sets a group from a TLS ECParameters record.
+ * \brief           This function sets up an ECP group context from a TLS
+ *                  ECParameters record as defined in RFC 4492, Section 5.4.
  *
- * \note            \p buf is updated to point right after the ECParameters record
- *                  on exit.
+ * \note            The read pointer \p buf is updated to point right after
+ *                  the ECParameters record on exit.
  *
- * \param grp       The destination group.
+ * \param grp       The group context to setup. This must be initialized.
  * \param buf       The address of the pointer to the start of the input buffer.
- * \param len       The length of the buffer.
+ * \param len       The length of the input buffer \c *buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization failure.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not
+ *                  recognized.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, const unsigned char **buf, size_t len );
+int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp,
+                                const unsigned char **buf, size_t len );
 
 /**
- * \brief           This function writes the TLS ECParameters record for a group.
+ * \brief           This function extracts an elliptic curve group ID from a
+ *                  TLS ECParameters record as defined in RFC 4492, Section 5.4.
  *
- * \param grp       The ECP group used.
- * \param olen      The number of Bytes written.
- * \param buf       The buffer to write to.
- * \param blen      The length of the buffer.
+ * \note            The read pointer \p buf is updated to point right after
+ *                  the ECParameters record on exit.
+ *
+ * \param grp       The address at which to store the group id.
+ *                  This must not be \c NULL.
+ * \param buf       The address of the pointer to the start of the input buffer.
+ * \param len       The length of the input buffer \c *buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not
+ *                  recognized.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
-                         unsigned char *buf, size_t blen );
+int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp,
+                                   const unsigned char **buf,
+                                   size_t len );
+/**
+ * \brief           This function exports an elliptic curve as a TLS
+ *                  ECParameters record as defined in RFC 4492, Section 5.4.
+ *
+ * \param grp       The ECP group to be exported.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param olen      The address at which to store the number of Bytes written.
+ *                  This must not be \c NULL.
+ * \param buf       The buffer to write to. This must be a writable buffer
+ *                  of length \p blen Bytes.
+ * \param blen      The length of the output buffer \p buf in Bytes.
+ *
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output
+ *                  buffer is too small to hold the exported group.
+ * \return          Another negative error code on other kinds of failure.
+ */
+int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp,
+                                 size_t *olen,
+                                 unsigned char *buf, size_t blen );
 
 /**
- * \brief           This function performs multiplication of a point by
- *                  an integer: \p R = \p m * \p P.
+ * \brief           This function performs a scalar multiplication of a point
+ *                  by an integer: \p R = \p m * \p P.
  *
  *                  It is not thread-safe to use same group in multiple threads.
  *
@@ -730,17 +814,22 @@ int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
  *                  targeting these results. We recommend always providing
  *                  a non-NULL \p f_rng. The overhead is negligible.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
- * \param m         The integer by which to multiply.
- * \param P         The point to multiply.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
+ * \param m         The integer by which to multiply. This must be initialized.
+ * \param P         The point to multiply. This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results isn't desired (discouraged).
+ * \param p_rng     The RNG context to be passed to \p p_rng.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private
  *                  key, or \p P is not a valid public key.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -756,12 +845,16 @@ int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
  *                  it can return early and restart according to the limit set
  *                  with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
- * \param m         The integer by which to multiply.
- * \param P         The point to multiply.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
+ * \param m         The integer by which to multiply. This must be initialized.
+ * \param P         The point to multiply. This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results isn't desired (discouraged).
+ * \param p_rng     The RNG context to be passed to \p p_rng.
  * \param rs_ctx    The restart context (NULL disables restart).
  *
  * \return          \c 0 on success.
@@ -770,6 +863,7 @@ int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
  *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -785,18 +879,25 @@ int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
  * \note            In contrast to mbedtls_ecp_mul(), this function does not
  *                  guarantee a constant execution flow and timing.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
  * \param m         The integer by which to multiply \p P.
- * \param P         The point to multiply by \p m.
+ *                  This must be initialized.
+ * \param P         The point to multiply by \p m. This must be initialized.
  * \param n         The integer by which to multiply \p Q.
+ *                  This must be initialized.
  * \param Q         The point to be multiplied by \p n.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not
  *                  valid private keys, or \p P or \p Q are not valid public
  *                  keys.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -813,12 +914,18 @@ int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
  * \param m         The integer by which to multiply \p P.
- * \param P         The point to multiply by \p m.
+ *                  This must be initialized.
+ * \param P         The point to multiply by \p m. This must be initialized.
  * \param n         The integer by which to multiply \p Q.
+ *                  This must be initialized.
  * \param Q         The point to be multiplied by \p n.
+ *                  This must be initialized.
  * \param rs_ctx    The restart context (NULL disables restart).
  *
  * \return          \c 0 on success.
@@ -828,6 +935,7 @@ int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
  *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_muladd_restartable(
              mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
@@ -852,38 +960,51 @@ int mbedtls_ecp_muladd_restartable(
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The curve the point should lie on.
- * \param pt        The point to check.
+ * \param grp       The ECP group the point should belong to.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param pt        The point to check. This must be initialized.
  *
  * \return          \c 0 if the point is a valid public key.
- * \return          #MBEDTLS_ERR_ECP_INVALID_KEY on failure.
+ * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not
+ *                  a valid public key for the given curve.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt );
+int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp,
+                              const mbedtls_ecp_point *pt );
 
 /**
- * \brief           This function checks that an \p mbedtls_mpi is a valid private
- *                  key for this curve.
+ * \brief           This function checks that an \p mbedtls_mpi is a
+ *                  valid private key for this curve.
  *
  * \note            This function uses bare components rather than an
  *                  ::mbedtls_ecp_keypair structure to ease use with other
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The group used.
- * \param d         The integer to check.
+ * \param grp       The ECP group the private key should belong to.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param d         The integer to check. This must be initialized.
  *
  * \return          \c 0 if the point is a valid private key.
- * \return          #MBEDTLS_ERR_ECP_INVALID_KEY on failure.
+ * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not a valid
+ *                  private key for the given curve.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, const mbedtls_mpi *d );
+int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp,
+                               const mbedtls_mpi *d );
 
 /**
  * \brief           This function generates a private key.
  *
- * \param grp       The ECP group.
- * \param d         The destination MPI (secret part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG parameter.
+ * \param grp       The ECP group to generate a private key for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param d         The destination MPI (secret part). This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
@@ -903,22 +1024,29 @@ int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp,
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The ECP group.
- * \param G         The chosen base point.
+ * \param grp       The ECP group to generate a key pair for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param G         The base point to use. This must be initialized
+ *                  and belong to \p grp. It replaces the default base
+ *                  point \c grp->G used by mbedtls_ecp_gen_keypair().
  * \param d         The destination MPI (secret part).
+ *                  This must be initialized.
  * \param Q         The destination point (public part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
 int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
-                     const mbedtls_ecp_point *G,
-                     mbedtls_mpi *d, mbedtls_ecp_point *Q,
-                     int (*f_rng)(void *, unsigned char *, size_t),
-                     void *p_rng );
+                                  const mbedtls_ecp_point *G,
+                                  mbedtls_mpi *d, mbedtls_ecp_point *Q,
+                                  int (*f_rng)(void *, unsigned char *, size_t),
+                                  void *p_rng );
 
 /**
  * \brief           This function generates an ECP keypair.
@@ -928,34 +1056,42 @@ int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to generate a key pair for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
  * \param d         The destination MPI (secret part).
+ *                  This must be initialized.
  * \param Q         The destination point (public part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
-int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q,
-                     int (*f_rng)(void *, unsigned char *, size_t),
-                     void *p_rng );
+int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d,
+                             mbedtls_ecp_point *Q,
+                             int (*f_rng)(void *, unsigned char *, size_t),
+                             void *p_rng );
 
 /**
  * \brief           This function generates an ECP key.
  *
  * \param grp_id    The ECP group identifier.
- * \param key       The destination key.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param key       The destination key. This must be initialized.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
 int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
-                int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+                         int (*f_rng)(void *, unsigned char *, size_t),
+                         void *p_rng );
 
 /**
  * \brief           This function checks that the keypair objects
@@ -963,16 +1099,19 @@ int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
  *                  same public point, and that the private key in
  *                  \p prv is consistent with the public key.
  *
- * \param pub       The keypair structure holding the public key.
- *                  If it contains a private key, that part is ignored.
+ * \param pub       The keypair structure holding the public key. This
+ *                  must be initialized. If it contains a private key, that
+ *                  part is ignored.
  * \param prv       The keypair structure holding the full keypair.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success, meaning that the keys are valid and match.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the keys are invalid or do not match.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX
  *                  error code on calculation failure.
  */
-int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv );
+int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub,
+                                const mbedtls_ecp_keypair *prv );
 
 #if defined(MBEDTLS_SELF_TEST)
 
diff --git a/features/mbedtls/inc/mbedtls/ecp_internal.h b/features/mbedtls/inc/mbedtls/ecp_internal.h
index 18040697ad..7625ed48e1 100644
--- a/features/mbedtls/inc/mbedtls/ecp_internal.h
+++ b/features/mbedtls/inc/mbedtls/ecp_internal.h
@@ -61,6 +61,12 @@
 #ifndef MBEDTLS_ECP_INTERNAL_H
 #define MBEDTLS_ECP_INTERNAL_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #if defined(MBEDTLS_ECP_INTERNAL_ALT)
 
 /**
diff --git a/features/mbedtls/inc/mbedtls/error.h b/features/mbedtls/inc/mbedtls/error.h
index 0c38889878..bee0fe485a 100644
--- a/features/mbedtls/inc/mbedtls/error.h
+++ b/features/mbedtls/inc/mbedtls/error.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_ERROR_H
 #define MBEDTLS_ERROR_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include <stddef.h>
 
 /**
@@ -74,9 +80,9 @@
  * MD4       1                  0x002D-0x002D
  * MD5       1                  0x002F-0x002F
  * RIPEMD160 1                  0x0031-0x0031
- * SHA1      1                  0x0035-0x0035
- * SHA256    1                  0x0037-0x0037
- * SHA512    1                  0x0039-0x0039
+ * SHA1      1                  0x0035-0x0035 0x0073-0x0073
+ * SHA256    1                  0x0037-0x0037 0x0074-0x0074
+ * SHA512    1                  0x0039-0x0039 0x0075-0x0075
  * CHACHA20  3                  0x0051-0x0055
  * POLY1305  3                  0x0057-0x005B
  * CHACHAPOLY 2 0x0054-0x0056
diff --git a/features/mbedtls/inc/mbedtls/gcm.h b/features/mbedtls/inc/mbedtls/gcm.h
index 93d15ee802..fd130abd7c 100644
--- a/features/mbedtls/inc/mbedtls/gcm.h
+++ b/features/mbedtls/inc/mbedtls/gcm.h
@@ -33,6 +33,12 @@
 #ifndef MBEDTLS_GCM_H
 #define MBEDTLS_GCM_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "cipher.h"
 
 #include <stdint.h>
@@ -85,7 +91,7 @@ mbedtls_gcm_context;
  *                  cipher, nor set the key. For this purpose, use
  *                  mbedtls_gcm_setkey().
  *
- * \param ctx       The GCM context to initialize.
+ * \param ctx       The GCM context to initialize. This must not be \c NULL.
  */
 void mbedtls_gcm_init( mbedtls_gcm_context *ctx );
 
@@ -93,9 +99,10 @@ void mbedtls_gcm_init( mbedtls_gcm_context *ctx );
  * \brief           This function associates a GCM context with a
  *                  cipher algorithm and a key.
  *
- * \param ctx       The GCM context to initialize.
+ * \param ctx       The GCM context. This must be initialized.
  * \param cipher    The 128-bit block cipher to use.
- * \param key       The encryption key.
+ * \param key       The encryption key. This must be a readable buffer of at
+ *                  least \p keybits bits.
  * \param keybits   The key size in bits. Valid options are:
  *                  <ul><li>128 bits</li>
  *                  <li>192 bits</li>
@@ -122,7 +129,8 @@ int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
  *                  authentic. You should use this function to perform encryption
  *                  only. For decryption, use mbedtls_gcm_auth_decrypt() instead.
  *
- * \param ctx       The GCM context to use for encryption or decryption.
+ * \param ctx       The GCM context to use for encryption or decryption. This
+ *                  must be initialized.
  * \param mode      The operation to perform:
  *                  - #MBEDTLS_GCM_ENCRYPT to perform authenticated encryption.
  *                    The ciphertext is written to \p output and the
@@ -136,21 +144,27 @@ int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
  *                    calling this function in decryption mode.
  * \param length    The length of the input data, which is equal to the length
  *                  of the output data.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer of
+ *                  at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data.
+ * \param add       The buffer holding the additional data. This must be of at
+ *                  least that size in Bytes.
  * \param add_len   The length of the additional data.
- * \param input     The buffer holding the input data. Its size is \b length.
- * \param output    The buffer for holding the output data. It must have room
- *                  for \b length bytes.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size in Bytes.
+ * \param output    The buffer for holding the output data. If \p length is greater
+ *                  than zero, this must be a writable buffer of at least that
+ *                  size in Bytes.
  * \param tag_len   The length of the tag to generate.
- * \param tag       The buffer for holding the tag.
+ * \param tag       The buffer for holding the tag. This must be a readable
+ *                  buffer of at least \p tag_len Bytes.
  *
  * \return          \c 0 if the encryption or decryption was performed
  *                  successfully. Note that in #MBEDTLS_GCM_DECRYPT mode,
  *                  this does not indicate that the data is authentic.
- * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths are not valid or
- *                  a cipher-specific error code if the encryption
+ * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths or pointers are
+ *                  not valid or a cipher-specific error code if the encryption
  *                  or decryption failed.
  */
 int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
@@ -173,23 +187,30 @@ int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
  *                  input buffer. If the buffers overlap, the output buffer
  *                  must trail at least 8 Bytes behind the input buffer.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param length    The length of the ciphertext to decrypt, which is also
  *                  the length of the decrypted plaintext.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer
+ *                  of at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data.
+ * \param add       The buffer holding the additional data. This must be of at
+ *                  least that size in Bytes.
  * \param add_len   The length of the additional data.
- * \param tag       The buffer holding the tag to verify.
+ * \param tag       The buffer holding the tag to verify. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the tag to verify.
- * \param input     The buffer holding the ciphertext. Its size is \b length.
- * \param output    The buffer for holding the decrypted plaintext. It must
- *                  have room for \b length bytes.
+ * \param input     The buffer holding the ciphertext. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size.
+ * \param output    The buffer for holding the decrypted plaintext. If \p length
+ *                  is greater than zero, this must be a writable buffer of at
+ *                  least that size.
  *
  * \return          \c 0 if successful and authenticated.
  * \return          #MBEDTLS_ERR_GCM_AUTH_FAILED if the tag does not match.
- * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths are not valid or
- *                  a cipher-specific error code if the decryption failed.
+ * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths or pointers are
+ *                  not valid or a cipher-specific error code if the decryption
+ *                  failed.
  */
 int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
                       size_t length,
@@ -206,15 +227,16 @@ int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
  * \brief           This function starts a GCM encryption or decryption
  *                  operation.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param mode      The operation to perform: #MBEDTLS_GCM_ENCRYPT or
  *                  #MBEDTLS_GCM_DECRYPT.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer of
+ *                  at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data, or NULL
- *                  if \p add_len is 0.
- * \param add_len   The length of the additional data. If 0,
- *                  \p add is NULL.
+ * \param add       The buffer holding the additional data, or \c NULL
+ *                  if \p add_len is \c 0.
+ * \param add_len   The length of the additional data. If \c 0,
+ *                  \p add may be \c NULL.
  *
  * \return          \c 0 on success.
  */
@@ -237,11 +259,15 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
  *                  input buffer. If the buffers overlap, the output buffer
  *                  must trail at least 8 Bytes behind the input buffer.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param length    The length of the input data. This must be a multiple of
  *                  16 except in the last call before mbedtls_gcm_finish().
- * \param input     The buffer holding the input data.
- * \param output    The buffer for holding the output data.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size in Bytes.
+ * \param output    The buffer for holding the output data. If \p length is
+ *                  greater than zero, this must be a writable buffer of at
+ *                  least that size in Bytes.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_GCM_BAD_INPUT on failure.
@@ -258,9 +284,11 @@ int mbedtls_gcm_update( mbedtls_gcm_context *ctx,
  *                  It wraps up the GCM stream, and generates the
  *                  tag. The tag can have a maximum length of 16 Bytes.
  *
- * \param ctx       The GCM context.
- * \param tag       The buffer for holding the tag.
- * \param tag_len   The length of the tag to generate. Must be at least four.
+ * \param ctx       The GCM context. This must be initialized.
+ * \param tag       The buffer for holding the tag. This must be a readable
+ *                  buffer of at least \p tag_len Bytes.
+ * \param tag_len   The length of the tag to generate. This must be at least
+ *                  four.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_GCM_BAD_INPUT on failure.
@@ -273,10 +301,13 @@ int mbedtls_gcm_finish( mbedtls_gcm_context *ctx,
  * \brief           This function clears a GCM context and the underlying
  *                  cipher sub-context.
  *
- * \param ctx       The GCM context to clear.
+ * \param ctx       The GCM context to clear. If this is \c NULL, the call has
+ *                  no effect. Otherwise, this must be initialized.
  */
 void mbedtls_gcm_free( mbedtls_gcm_context *ctx );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The GCM checkup routine.
  *
@@ -285,6 +316,8 @@ void mbedtls_gcm_free( mbedtls_gcm_context *ctx );
  */
 int mbedtls_gcm_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/havege.h b/features/mbedtls/inc/mbedtls/havege.h
index 57e8c40943..4c1c86087a 100644
--- a/features/mbedtls/inc/mbedtls/havege.h
+++ b/features/mbedtls/inc/mbedtls/havege.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_HAVEGE_H
 #define MBEDTLS_HAVEGE_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include <stddef.h>
 
 #define MBEDTLS_HAVEGE_COLLECT_SIZE 1024
diff --git a/features/mbedtls/inc/mbedtls/hkdf.h b/features/mbedtls/inc/mbedtls/hkdf.h
index e6ed7cde97..40ee64eb03 100644
--- a/features/mbedtls/inc/mbedtls/hkdf.h
+++ b/features/mbedtls/inc/mbedtls/hkdf.h
@@ -27,6 +27,12 @@
 #ifndef MBEDTLS_HKDF_H
 #define MBEDTLS_HKDF_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "md.h"
 
 /**
diff --git a/features/mbedtls/inc/mbedtls/hmac_drbg.h b/features/mbedtls/inc/mbedtls/hmac_drbg.h
index 3bc675ec7c..f1289cb306 100644
--- a/features/mbedtls/inc/mbedtls/hmac_drbg.h
+++ b/features/mbedtls/inc/mbedtls/hmac_drbg.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_HMAC_DRBG_H
 #define MBEDTLS_HMAC_DRBG_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "md.h"
 
 #if defined(MBEDTLS_THREADING_C)
@@ -76,7 +82,7 @@ extern "C" {
  */
 typedef struct mbedtls_hmac_drbg_context
 {
-    /* Working state: the key K is not stored explicitely,
+    /* Working state: the key K is not stored explicitly,
      * but is implied by the HMAC context */
     mbedtls_md_context_t md_ctx;                    /*!< HMAC context (inc. K)  */
     unsigned char V[MBEDTLS_MD_MAX_SIZE];  /*!< V in the spec          */
@@ -195,10 +201,13 @@ void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
  * \param additional    Additional data to update state with, or NULL
  * \param add_len       Length of additional data, or 0
  *
+ * \return              \c 0 on success, or an error from the underlying
+ *                      hash calculation.
+ *
  * \note                Additional data is optional, pass NULL and 0 as second
  *                      third argument if no additional data is being used.
  */
-void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
+int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
                        const unsigned char *additional, size_t add_len );
 
 /**
@@ -257,6 +266,31 @@ int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len
  */
 void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
 
+#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED    __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief               HMAC_DRBG update state
+ *
+ * \deprecated          Superseded by mbedtls_hmac_drbg_update_ret()
+ *                      in 2.16.0.
+ *
+ * \param ctx           HMAC_DRBG context
+ * \param additional    Additional data to update state with, or NULL
+ * \param add_len       Length of additional data, or 0
+ *
+ * \note                Additional data is optional, pass NULL and 0 as second
+ *                      third argument if no additional data is being used.
+ */
+MBEDTLS_DEPRECATED void mbedtls_hmac_drbg_update(
+    mbedtls_hmac_drbg_context *ctx,
+    const unsigned char *additional, size_t add_len );
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+
 #if defined(MBEDTLS_FS_IO)
 /**
  * \brief               Write a seed file
diff --git a/features/mbedtls/inc/mbedtls/md2.h b/features/mbedtls/inc/mbedtls/md2.h
index f9bd98f804..fe97cf08d4 100644
--- a/features/mbedtls/inc/mbedtls/md2.h
+++ b/features/mbedtls/inc/mbedtls/md2.h
@@ -283,6 +283,8 @@ MBEDTLS_DEPRECATED void mbedtls_md2( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -295,6 +297,8 @@ MBEDTLS_DEPRECATED void mbedtls_md2( const unsigned char *input,
  */
 int mbedtls_md2_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/md4.h b/features/mbedtls/inc/mbedtls/md4.h
index dc3c048949..ce703c0ba4 100644
--- a/features/mbedtls/inc/mbedtls/md4.h
+++ b/features/mbedtls/inc/mbedtls/md4.h
@@ -288,6 +288,8 @@ MBEDTLS_DEPRECATED void mbedtls_md4( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -300,6 +302,8 @@ MBEDTLS_DEPRECATED void mbedtls_md4( const unsigned char *input,
  */
 int mbedtls_md4_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/md5.h b/features/mbedtls/inc/mbedtls/md5.h
index 6c3354fd30..6eed6cc864 100644
--- a/features/mbedtls/inc/mbedtls/md5.h
+++ b/features/mbedtls/inc/mbedtls/md5.h
@@ -288,6 +288,8 @@ MBEDTLS_DEPRECATED void mbedtls_md5( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -300,6 +302,8 @@ MBEDTLS_DEPRECATED void mbedtls_md5( const unsigned char *input,
  */
 int mbedtls_md5_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/net.h b/features/mbedtls/inc/mbedtls/net.h
index 6c13b53fb9..8cead58e5d 100644
--- a/features/mbedtls/inc/mbedtls/net.h
+++ b/features/mbedtls/inc/mbedtls/net.h
@@ -23,6 +23,11 @@
  *
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
 
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 #include "net_sockets.h"
diff --git a/features/mbedtls/inc/mbedtls/nist_kw.h b/features/mbedtls/inc/mbedtls/nist_kw.h
index 5a0f656a8f..3b67b59cd2 100644
--- a/features/mbedtls/inc/mbedtls/nist_kw.h
+++ b/features/mbedtls/inc/mbedtls/nist_kw.h
@@ -37,6 +37,12 @@
 #ifndef MBEDTLS_NIST_KW_H
 #define MBEDTLS_NIST_KW_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "cipher.h"
 
 #ifdef __cplusplus
diff --git a/features/mbedtls/inc/mbedtls/padlock.h b/features/mbedtls/inc/mbedtls/padlock.h
index 677936ebf8..f05b72b077 100644
--- a/features/mbedtls/inc/mbedtls/padlock.h
+++ b/features/mbedtls/inc/mbedtls/padlock.h
@@ -3,6 +3,9 @@
  *
  * \brief VIA PadLock ACE for HW encryption/decryption supported by some
  *        processors
+ *
+ * \warning These functions are only for internal use by other library
+ *          functions; you must not call them directly.
  */
 /*
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
@@ -25,6 +28,12 @@
 #ifndef MBEDTLS_PADLOCK_H
 #define MBEDTLS_PADLOCK_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "aes.h"
 
 #define MBEDTLS_ERR_PADLOCK_DATA_MISALIGNED               -0x0030  /**< Input data should be aligned. */
@@ -57,7 +66,10 @@ extern "C" {
 #endif
 
 /**
- * \brief          PadLock detection routine
+ * \brief          Internal PadLock detection routine
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param feature  The feature to detect
  *
@@ -66,7 +78,10 @@ extern "C" {
 int mbedtls_padlock_has_support( int feature );
 
 /**
- * \brief          PadLock AES-ECB block en(de)cryption
+ * \brief          Internal PadLock AES-ECB block en(de)cryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -76,12 +91,15 @@ int mbedtls_padlock_has_support( int feature );
  * \return         0 if success, 1 if operation failed
  */
 int mbedtls_padlock_xcryptecb( mbedtls_aes_context *ctx,
-                       int mode,
-                       const unsigned char input[16],
-                       unsigned char output[16] );
+                               int mode,
+                               const unsigned char input[16],
+                               unsigned char output[16] );
 
 /**
- * \brief          PadLock AES-CBC buffer en(de)cryption
+ * \brief          Internal PadLock AES-CBC buffer en(de)cryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -93,11 +111,11 @@ int mbedtls_padlock_xcryptecb( mbedtls_aes_context *ctx,
  * \return         0 if success, 1 if operation failed
  */
 int mbedtls_padlock_xcryptcbc( mbedtls_aes_context *ctx,
-                       int mode,
-                       size_t length,
-                       unsigned char iv[16],
-                       const unsigned char *input,
-                       unsigned char *output );
+                               int mode,
+                               size_t length,
+                               unsigned char iv[16],
+                               const unsigned char *input,
+                               unsigned char *output );
 
 #ifdef __cplusplus
 }
diff --git a/features/mbedtls/inc/mbedtls/pem.h b/features/mbedtls/inc/mbedtls/pem.h
index fa82f7bdbd..a29e9ce300 100644
--- a/features/mbedtls/inc/mbedtls/pem.h
+++ b/features/mbedtls/inc/mbedtls/pem.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_PEM_H
 #define MBEDTLS_PEM_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include <stddef.h>
 
 /**
diff --git a/features/mbedtls/inc/mbedtls/pk.h b/features/mbedtls/inc/mbedtls/pk.h
index 862065eede..24951a6e1f 100644
--- a/features/mbedtls/inc/mbedtls/pk.h
+++ b/features/mbedtls/inc/mbedtls/pk.h
@@ -202,12 +202,18 @@ typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)( void *ctx );
 const mbedtls_pk_info_t *mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type );
 
 /**
- * \brief           Initialize a mbedtls_pk_context (as NONE)
+ * \brief           Initialize a #mbedtls_pk_context (as NONE).
+ *
+ * \param ctx       The context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_pk_init( mbedtls_pk_context *ctx );
 
 /**
- * \brief           Free a mbedtls_pk_context
+ * \brief           Free the components of a #mbedtls_pk_context.
+ *
+ * \param ctx       The context to clear. It must have been initialized.
+ *                  If this is \c NULL, this function does nothing.
  *
  * \note            For contexts that have been set up with
  *                  mbedtls_pk_setup_opaque(), this does not free the underlying
@@ -219,11 +225,17 @@ void mbedtls_pk_free( mbedtls_pk_context *ctx );
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
 /**
  * \brief           Initialize a restart context
+ *
+ * \param ctx       The context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx );
 
 /**
  * \brief           Free the components of a restart context
+ *
+ * \param ctx       The context to clear. It must have been initialized.
+ *                  If this is \c NULL, this function does nothing.
  */
 void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx );
 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
@@ -232,7 +244,8 @@ void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx );
  * \brief           Initialize a PK context with the information given
  *                  and allocates the type-specific PK subcontext.
  *
- * \param ctx       Context to initialize. Must be empty (type NONE).
+ * \param ctx       Context to initialize. It must not have been set
+ *                  up yet (type #MBEDTLS_PK_NONE).
  * \param info      Information to use
  *
  * \return          0 on success,
@@ -273,14 +286,15 @@ int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info );
  *                  ECC key pair.
  * \return          #MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
  */
-int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_slot_t key );
+int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_handle_t key );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 /**
  * \brief           Initialize an RSA-alt context
  *
- * \param ctx       Context to initialize. Must be empty (type NONE).
+ * \param ctx       Context to initialize. It must not have been set
+ *                  up yet (type #MBEDTLS_PK_NONE).
  * \param key       RSA key pointer
  * \param decrypt_func  Decryption function
  * \param sign_func     Signing function
@@ -300,7 +314,7 @@ int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
 /**
  * \brief           Get the size in bits of the underlying key
  *
- * \param ctx       Context to use
+ * \param ctx       The context to query. It must have been initialized.
  *
  * \return          Key size in bits, or 0 on error
  */
@@ -308,7 +322,8 @@ size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx );
 
 /**
  * \brief           Get the length in bytes of the underlying key
- * \param ctx       Context to use
+ *
+ * \param ctx       The context to query. It must have been initialized.
  *
  * \return          Key length in bytes, or 0 on error
  */
@@ -320,18 +335,21 @@ static inline size_t mbedtls_pk_get_len( const mbedtls_pk_context *ctx )
 /**
  * \brief           Tell if a context can do the operation given by type
  *
- * \param ctx       Context to test
- * \param type      Target type
+ * \param ctx       The context to query. It must have been initialized.
+ * \param type      The desired type.
  *
- * \return          0 if context can't do the operations,
- *                  1 otherwise.
+ * \return          1 if the context can do operations on the given type.
+ * \return          0 if the context cannot do the operations on the given
+ *                  type. This is always the case for a context that has
+ *                  been initialized but not set up, or that has been
+ *                  cleared with mbedtls_pk_free().
  */
 int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type );
 
 /**
  * \brief           Verify signature (including padding if relevant).
  *
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -364,7 +382,7 @@ int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
  *                  \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
  *                  operations. For RSA, same as \c mbedtls_pk_verify().
  *
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -388,7 +406,7 @@ int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx,
  *
  * \param type      Signature type (inc. possible padding type) to verify
  * \param options   Pointer to type-specific options, or NULL
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -419,7 +437,8 @@ int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options,
 /**
  * \brief           Make signature, including padding if relevant.
  *
- * \param ctx       PK context to use - must hold a private key
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -453,7 +472,8 @@ int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
  *                  \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
  *                  operations. For RSA, same as \c mbedtls_pk_sign().
  *
- * \param ctx       PK context to use - must hold a private key
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -477,7 +497,8 @@ int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
 /**
  * \brief           Decrypt message (including padding if relevant).
  *
- * \param ctx       PK context to use - must hold a private key
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
  * \param input     Input to decrypt
  * \param ilen      Input size
  * \param output    Decrypted output
@@ -498,7 +519,7 @@ int mbedtls_pk_decrypt( mbedtls_pk_context *ctx,
 /**
  * \brief           Encrypt message (including padding if relevant).
  *
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param input     Message to encrypt
  * \param ilen      Message size
  * \param output    Encrypted output
@@ -533,7 +554,7 @@ int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_conte
 /**
  * \brief           Export debug information
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  * \param items     Place to write debug items
  *
  * \return          0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
@@ -543,7 +564,7 @@ int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *item
 /**
  * \brief           Access the type name
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  *
  * \return          Type name on success, or "invalid PK"
  */
@@ -552,9 +573,10 @@ const char * mbedtls_pk_get_name( const mbedtls_pk_context *ctx );
 /**
  * \brief           Get the key type
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  *
- * \return          Type on success, or MBEDTLS_PK_NONE
+ * \return          Type on success.
+ * \return          #MBEDTLS_PK_NONE for a context that has not been set up.
  */
 mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
 
@@ -563,12 +585,22 @@ mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
 /**
  * \brief           Parse a private key in PEM or DER format
  *
- * \param ctx       key to be initialized
- * \param key       input buffer
- * \param keylen    size of the buffer
- *                  (including the terminating null byte for PEM data)
- * \param pwd       password for decryption (optional)
- * \param pwdlen    size of the password
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
+ * \param key       Input buffer to parse.
+ *                  The buffer must contain the input exactly, with no
+ *                  extra trailing material. For PEM, the buffer must
+ *                  contain a null-terminated string.
+ * \param keylen    Size of \b key in bytes.
+ *                  For PEM data, this includes the terminating null byte,
+ *                  so \p keylen must be equal to `strlen(key) + 1`.
+ * \param pwd       Optional password for decryption.
+ *                  Pass \c NULL if expecting a non-encrypted key.
+ *                  Pass a string of \p pwdlen bytes if expecting an encrypted
+ *                  key; a non-encrypted key will also be accepted.
+ *                  The empty password is not supported.
+ * \param pwdlen    Size of the password in bytes.
+ *                  Ignored if \p pwd is \c NULL.
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -586,10 +618,15 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *ctx,
 /**
  * \brief           Parse a public key in PEM or DER format
  *
- * \param ctx       key to be initialized
- * \param key       input buffer
- * \param keylen    size of the buffer
- *                  (including the terminating null byte for PEM data)
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
+ * \param key       Input buffer to parse.
+ *                  The buffer must contain the input exactly, with no
+ *                  extra trailing material. For PEM, the buffer must
+ *                  contain a null-terminated string.
+ * \param keylen    Size of \b key in bytes.
+ *                  For PEM data, this includes the terminating null byte,
+ *                  so \p keylen must be equal to `strlen(key) + 1`.
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -607,9 +644,14 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
 /**
  * \brief           Load and parse a private key
  *
- * \param ctx       key to be initialized
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
  * \param path      filename to read the private key from
- * \param password  password to decrypt the file (can be NULL)
+ * \param password  Optional password to decrypt the file.
+ *                  Pass \c NULL if expecting a non-encrypted key.
+ *                  Pass a null-terminated string if expecting an encrypted
+ *                  key; a non-encrypted key will also be accepted.
+ *                  The empty password is not supported.
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -626,7 +668,8 @@ int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
 /**
  * \brief           Load and parse a public key
  *
- * \param ctx       key to be initialized
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
  * \param path      filename to read the public key from
  *
  * \note            On entry, ctx must be empty, either freshly initialised
@@ -649,7 +692,7 @@ int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path )
  *                        return value to determine where you should start
  *                        using the buffer
  *
- * \param ctx       private to write away
+ * \param ctx       PK context which must contain a valid private key.
  * \param buf       buffer to write to
  * \param size      size of the buffer
  *
@@ -664,7 +707,7 @@ int mbedtls_pk_write_key_der( mbedtls_pk_context *ctx, unsigned char *buf, size_
  *                        return value to determine where you should start
  *                        using the buffer
  *
- * \param ctx       public key to write away
+ * \param ctx       PK context which must contain a valid public or private key.
  * \param buf       buffer to write to
  * \param size      size of the buffer
  *
@@ -677,9 +720,10 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *ctx, unsigned char *buf, si
 /**
  * \brief           Write a public key to a PEM string
  *
- * \param ctx       public key to write away
- * \param buf       buffer to write to
- * \param size      size of the buffer
+ * \param ctx       PK context which must contain a valid public or private key.
+ * \param buf       Buffer to write to. The output includes a
+ *                  terminating null byte.
+ * \param size      Size of the buffer in bytes.
  *
  * \return          0 if successful, or a specific error code
  */
@@ -688,9 +732,10 @@ int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *ctx, unsigned char *buf, si
 /**
  * \brief           Write a private key to a PKCS#1 or SEC1 PEM string
  *
- * \param ctx       private to write away
- * \param buf       buffer to write to
- * \param size      size of the buffer
+ * \param ctx       PK context which must contain a valid private key.
+ * \param buf       Buffer to write to. The output includes a
+ *                  terminating null byte.
+ * \param size      Size of the buffer in bytes.
  *
  * \return          0 if successful, or a specific error code
  */
@@ -709,7 +754,8 @@ int mbedtls_pk_write_key_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_
  *
  * \param p         the position in the ASN.1 data
  * \param end       end of the buffer
- * \param pk        the key to fill
+ * \param pk        The PK context to fill. It must have been initialized
+ *                  but not set up.
  *
  * \return          0 if successful, or a specific PK error code
  */
@@ -724,7 +770,7 @@ int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
  *
  * \param p         reference to current position pointer
  * \param start     start of the buffer (for bounds-checking)
- * \param key       public key to write away
+ * \param key       PK context which must contain a valid public or private key.
  *
  * \return          the length written or a negative error code
  */
@@ -761,7 +807,7 @@ int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n );
  * \return          An Mbed TLS error code otherwise.
  */
 int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
-                               psa_key_slot_t *slot,
+                               psa_key_handle_t *slot,
                                psa_algorithm_t hash_alg );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
diff --git a/features/mbedtls/inc/mbedtls/pkcs12.h b/features/mbedtls/inc/mbedtls/pkcs12.h
index a621ef5b15..d441357b7f 100644
--- a/features/mbedtls/inc/mbedtls/pkcs12.h
+++ b/features/mbedtls/inc/mbedtls/pkcs12.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_PKCS12_H
 #define MBEDTLS_PKCS12_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "md.h"
 #include "cipher.h"
 #include "asn1.h"
@@ -46,6 +52,8 @@
 extern "C" {
 #endif
 
+#if defined(MBEDTLS_ASN1_PARSE_C)
+
 /**
  * \brief            PKCS12 Password Based function (encryption / decryption)
  *                   for pbeWithSHAAnd128BitRC4
@@ -87,6 +95,8 @@ int mbedtls_pkcs12_pbe( mbedtls_asn1_buf *pbe_params, int mode,
                 const unsigned char *input, size_t len,
                 unsigned char *output );
 
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
 /**
  * \brief            The PKCS#12 derivation function uses a password and a salt
  *                   to produce pseudo-random bits for a particular "purpose".
diff --git a/features/mbedtls/inc/mbedtls/pkcs5.h b/features/mbedtls/inc/mbedtls/pkcs5.h
index 9a3c9fddcc..c92185f7a6 100644
--- a/features/mbedtls/inc/mbedtls/pkcs5.h
+++ b/features/mbedtls/inc/mbedtls/pkcs5.h
@@ -26,6 +26,12 @@
 #ifndef MBEDTLS_PKCS5_H
 #define MBEDTLS_PKCS5_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "asn1.h"
 #include "md.h"
 
@@ -44,6 +50,8 @@
 extern "C" {
 #endif
 
+#if defined(MBEDTLS_ASN1_PARSE_C)
+
 /**
  * \brief          PKCS#5 PBES2 function
  *
@@ -62,6 +70,8 @@ int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode,
                  const unsigned char *data, size_t datalen,
                  unsigned char *output );
 
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
 /**
  * \brief          PKCS#5 PBKDF2 using HMAC
  *
@@ -81,6 +91,8 @@ int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *p
                        unsigned int iteration_count,
                        uint32_t key_length, unsigned char *output );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -88,6 +100,8 @@ int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *p
  */
 int mbedtls_pkcs5_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/platform.h b/features/mbedtls/inc/mbedtls/platform.h
index 89fe8a7b19..801a948bc5 100644
--- a/features/mbedtls/inc/mbedtls/platform.h
+++ b/features/mbedtls/inc/mbedtls/platform.h
@@ -58,17 +58,33 @@ extern "C" {
  * \{
  */
 
+/* The older Microsoft Windows common runtime provides non-conforming
+ * implementations of some standard library functions, including snprintf
+ * and vsnprintf. This affects MSVC and MinGW builds.
+ */
+#if defined(__MINGW32__) || (defined(_MSC_VER) && _MSC_VER <= 1900)
+#define MBEDTLS_PLATFORM_HAS_NON_CONFORMING_SNPRINTF
+#define MBEDTLS_PLATFORM_HAS_NON_CONFORMING_VSNPRINTF
+#endif
+
 #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS)
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
-#if defined(_WIN32)
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_SNPRINTF)
 #define MBEDTLS_PLATFORM_STD_SNPRINTF   mbedtls_platform_win32_snprintf /**< The default \c snprintf function to use.  */
 #else
 #define MBEDTLS_PLATFORM_STD_SNPRINTF   snprintf /**< The default \c snprintf function to use.  */
 #endif
 #endif
+#if !defined(MBEDTLS_PLATFORM_STD_VSNPRINTF)
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_VSNPRINTF)
+#define MBEDTLS_PLATFORM_STD_VSNPRINTF   mbedtls_platform_win32_vsnprintf /**< The default \c vsnprintf function to use.  */
+#else
+#define MBEDTLS_PLATFORM_STD_VSNPRINTF   vsnprintf /**< The default \c vsnprintf function to use.  */
+#endif
+#endif
 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
 #define MBEDTLS_PLATFORM_STD_PRINTF   printf /**< The default \c printf function to use. */
 #endif
@@ -204,7 +220,7 @@ int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) );
  * - however it is acceptable to return -1 instead of the required length when
  *   the destination buffer is too short.
  */
-#if defined(_WIN32)
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_SNPRINTF)
 /* For Windows (inc. MSYS2), we provide our own fixed implementation */
 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... );
 #endif
@@ -230,6 +246,41 @@ int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
 #endif /* MBEDTLS_PLATFORM_SNPRINTF_MACRO */
 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
 
+/*
+ * The function pointers for vsnprintf
+ *
+ * The vsnprintf implementation should conform to C99:
+ * - it *must* always correctly zero-terminate the buffer
+ *   (except when n == 0, then it must leave the buffer untouched)
+ * - however it is acceptable to return -1 instead of the required length when
+ *   the destination buffer is too short.
+ */
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_VSNPRINTF)
+/* For Older Windows (inc. MSYS2), we provide our own fixed implementation */
+int mbedtls_platform_win32_vsnprintf( char *s, size_t n, const char *fmt, va_list arg );
+#endif
+
+#if defined(MBEDTLS_PLATFORM_VSNPRINTF_ALT)
+#include <stdarg.h>
+extern int (*mbedtls_vsnprintf)( char * s, size_t n, const char * format, va_list arg );
+
+/**
+ * \brief   Set your own snprintf function pointer
+ *
+ * \param   vsnprintf_func   The \c vsnprintf function implementation
+ *
+ * \return  \c 0
+ */
+int mbedtls_platform_set_vsnprintf( int (*vsnprintf_func)( char * s, size_t n,
+                                                 const char * format, va_list arg ) );
+#else /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
+#if defined(MBEDTLS_PLATFORM_VSNPRINTF_MACRO)
+#define mbedtls_vsnprintf   MBEDTLS_PLATFORM_VSNPRINTF_MACRO
+#else
+#define mbedtls_vsnprintf   vsnprintf
+#endif /* MBEDTLS_PLATFORM_VSNPRINTF_MACRO */
+#endif /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
+
 /*
  * The function pointers for exit
  */
diff --git a/features/mbedtls/inc/mbedtls/platform_util.h b/features/mbedtls/inc/mbedtls/platform_util.h
index 164a1a05f9..dba6d45982 100644
--- a/features/mbedtls/inc/mbedtls/platform_util.h
+++ b/features/mbedtls/inc/mbedtls/platform_util.h
@@ -26,14 +26,14 @@
 #define MBEDTLS_PLATFORM_UTIL_H
 
 #if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
+#include "config.h"
 #else
 #include MBEDTLS_CONFIG_FILE
 #endif
 
 #include <stddef.h>
 #if defined(MBEDTLS_HAVE_TIME_DATE)
-#include "mbedtls/platform_time.h"
+#include "platform_time.h"
 #include <time.h>
 #endif /* MBEDTLS_HAVE_TIME_DATE */
 
@@ -41,6 +41,88 @@
 extern "C" {
 #endif
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+
+#if defined(MBEDTLS_PARAM_FAILED)
+/** An alternative definition of MBEDTLS_PARAM_FAILED has been set in config.h.
+ *
+ * This flag can be used to check whether it is safe to assume that
+ * MBEDTLS_PARAM_FAILED() will expand to a call to mbedtls_param_failed().
+ */
+#define MBEDTLS_PARAM_FAILED_ALT
+#else /* MBEDTLS_PARAM_FAILED */
+#define MBEDTLS_PARAM_FAILED( cond ) \
+    mbedtls_param_failed( #cond, __FILE__, __LINE__ )
+
+/**
+ * \brief       User supplied callback function for parameter validation failure.
+ *              See #MBEDTLS_CHECK_PARAMS for context.
+ *
+ *              This function will be called unless an alternative treatement
+ *              is defined through the #MBEDTLS_PARAM_FAILED macro.
+ *
+ *              This function can return, and the operation will be aborted, or
+ *              alternatively, through use of setjmp()/longjmp() can resume
+ *              execution in the application code.
+ *
+ * \param failure_condition The assertion that didn't hold.
+ * \param file  The file where the assertion failed.
+ * \param line  The line in the file where the assertion failed.
+ */
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line );
+#endif /* MBEDTLS_PARAM_FAILED */
+
+/* Internal macro meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret )  \
+    do {                                            \
+        if( !(cond) )                               \
+        {                                           \
+            MBEDTLS_PARAM_FAILED( cond );           \
+            return( ret );                          \
+        }                                           \
+    } while( 0 )
+
+/* Internal macro meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE( cond )           \
+    do {                                            \
+        if( !(cond) )                               \
+        {                                           \
+            MBEDTLS_PARAM_FAILED( cond );           \
+            return;                                 \
+        }                                           \
+    } while( 0 )
+
+#else /* MBEDTLS_CHECK_PARAMS */
+
+/* Internal macros meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret )  do { } while( 0 )
+#define MBEDTLS_INTERNAL_VALIDATE( cond )           do { } while( 0 )
+
+#endif /* MBEDTLS_CHECK_PARAMS */
+
+/* Internal helper macros for deprecating API constants. */
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+/* Deliberately don't (yet) export MBEDTLS_DEPRECATED here
+ * to avoid conflict with other headers which define and use
+ * it, too. We might want to move all these definitions here at
+ * some point for uniformity. */
+#define MBEDTLS_DEPRECATED __attribute__((deprecated))
+MBEDTLS_DEPRECATED typedef char const * mbedtls_deprecated_string_constant_t;
+#define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL )       \
+    ( (mbedtls_deprecated_string_constant_t) ( VAL ) )
+MBEDTLS_DEPRECATED typedef int mbedtls_deprecated_numeric_constant_t;
+#define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL )       \
+    ( (mbedtls_deprecated_numeric_constant_t) ( VAL ) )
+#undef MBEDTLS_DEPRECATED
+#else /* MBEDTLS_DEPRECATED_WARNING */
+#define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL
+#define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) VAL
+#endif /* MBEDTLS_DEPRECATED_WARNING */
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
 /**
  * \brief       Securely zeroize a buffer
  *
diff --git a/features/mbedtls/inc/mbedtls/poly1305.h b/features/mbedtls/inc/mbedtls/poly1305.h
index b02f968b5e..f0ec44c968 100644
--- a/features/mbedtls/inc/mbedtls/poly1305.h
+++ b/features/mbedtls/inc/mbedtls/poly1305.h
@@ -34,7 +34,7 @@
 #define MBEDTLS_POLY1305_H
 
 #if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
+#include "config.h"
 #else
 #include MBEDTLS_CONFIG_FILE
 #endif
@@ -84,14 +84,18 @@ mbedtls_poly1305_context;
  *                  \c mbedtls_poly1305_finish(), then finally
  *                  \c mbedtls_poly1305_free().
  *
- * \param ctx       The Poly1305 context to initialize.
+ * \param ctx       The Poly1305 context to initialize. This must
+ *                  not be \c NULL.
  */
 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified Poly1305 context.
+ * \brief           This function releases and clears the specified
+ *                  Poly1305 context.
  *
- * \param ctx       The Poly1305 context to clear.
+ * \param ctx       The Poly1305 context to clear. This may be \c NULL, in which
+ *                  case this function is a no-op. If it is not \c NULL, it must
+ *                  point to an initialized Poly1305 context.
  */
 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx );
 
@@ -102,11 +106,11 @@ void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx );
  *                  invocation of Poly1305.
  *
  * \param ctx       The Poly1305 context to which the key should be bound.
- * \param key       The buffer containing the 256-bit key.
+ *                  This must be initialized.
+ * \param key       The buffer containing the \c 32 Byte (\c 256 Bit) key.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or key are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx,
                              const unsigned char key[32] );
@@ -120,13 +124,14 @@ int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx,
  *                  It can be called repeatedly to process a stream of data.
  *
  * \param ctx       The Poly1305 context to use for the Poly1305 operation.
- * \param ilen      The length of the input data (in bytes). Any value is accepted.
+ *                  This must be initialized and bound to a key.
+ * \param ilen      The length of the input data in Bytes.
+ *                  Any value is accepted.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or input are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
                              const unsigned char *input,
@@ -137,12 +142,12 @@ int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
  *                  Authentication Code (MAC).
  *
  * \param ctx       The Poly1305 context to use for the Poly1305 operation.
- * \param mac       The buffer to where the MAC is written. Must be big enough
- *                  to hold the 16-byte MAC.
+ *                  This must be initialized and bound to a key.
+ * \param mac       The buffer to where the MAC is written. This must
+ *                  be a writable buffer of length \c 16 Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
                              unsigned char mac[16] );
@@ -154,16 +159,16 @@ int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
  * \warning         The key must be unique and unpredictable for each
  *                  invocation of Poly1305.
  *
- * \param key       The buffer containing the 256-bit key.
- * \param ilen      The length of the input data (in bytes). Any value is accepted.
+ * \param key       The buffer containing the \c 32 Byte (\c 256 Bit) key.
+ * \param ilen      The length of the input data in Bytes.
+ *                  Any value is accepted.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if ilen == 0.
- * \param mac       The buffer to where the MAC is written. Must be big enough
- *                  to hold the 16-byte MAC.
+ *                  This pointer can be \c NULL if `ilen == 0`.
+ * \param mac       The buffer to where the MAC is written. This must be
+ *                  a writable buffer of length \c 16 Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if key, input, or mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_mac( const unsigned char key[32],
                           const unsigned char *input,
diff --git a/features/mbedtls/inc/mbedtls/psa_util.h b/features/mbedtls/inc/mbedtls/psa_util.h
index 5766133097..b0c0428270 100644
--- a/features/mbedtls/inc/mbedtls/psa_util.h
+++ b/features/mbedtls/inc/mbedtls/psa_util.h
@@ -41,21 +41,9 @@
 #include "ecp.h"
 #include "md.h"
 #include "pk.h"
+#include "oid.h"
 
-/* Slot allocation */
-
-static inline psa_status_t mbedtls_psa_get_free_key_slot( psa_key_slot_t *key )
-{
-    for( psa_key_slot_t slot = 1; slot <= 32; slot++ )
-    {
-        if( psa_get_key_information( slot, NULL, NULL ) == PSA_ERROR_EMPTY_SLOT )
-        {
-            *key = slot;
-            return( PSA_SUCCESS );
-        }
-    }
-    return( PSA_ERROR_INSUFFICIENT_MEMORY );
-}
+#include <string.h>
 
 /* Translations for symmetric crypto. */
 
@@ -105,6 +93,7 @@ static inline psa_algorithm_t mbedtls_psa_translate_cipher_mode(
             if( taglen == 0 )
                 return( PSA_ALG_CBC_NO_PADDING );
             /* Intentional fallthrough for taglen != 0 */
+            /* fallthrough */
         default:
             return( 0 );
     }
@@ -170,6 +159,162 @@ static inline psa_algorithm_t mbedtls_psa_translate_md( mbedtls_md_type_t md_alg
 
 /* Translations for ECC. */
 
+static inline int mbedtls_psa_get_ecc_oid_from_id(
+    psa_ecc_curve_t curve, char const **oid, size_t *oid_len )
+{
+    switch( curve )
+    {
+#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
+        case PSA_ECC_CURVE_SECP192R1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP192R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP192R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP192R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
+        case PSA_ECC_CURVE_SECP224R1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP224R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP224R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP224R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
+        case PSA_ECC_CURVE_SECP256R1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP256R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP256R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP256R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
+        case PSA_ECC_CURVE_SECP384R1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP384R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP384R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP384R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
+        case PSA_ECC_CURVE_SECP521R1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP521R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP521R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP521R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
+        case PSA_ECC_CURVE_SECP192K1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP192K1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP192K1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
+        case PSA_ECC_CURVE_SECP224K1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP224K1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP224K1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
+        case PSA_ECC_CURVE_SECP256K1:
+            *oid = MBEDTLS_OID_EC_GRP_SECP256K1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP256K1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
+        case PSA_ECC_CURVE_BRAINPOOL_P256R1:
+            *oid = MBEDTLS_OID_EC_GRP_BP256R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP256R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_BP256R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
+        case PSA_ECC_CURVE_BRAINPOOL_P384R1:
+            *oid = MBEDTLS_OID_EC_GRP_BP384R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP384R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_BP384R1_ENABLED */
+#if defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
+        case PSA_ECC_CURVE_BRAINPOOL_P512R1:
+            *oid = MBEDTLS_OID_EC_GRP_BP512R1;
+            *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP512R1 );
+            return( 0 );
+#endif /* MBEDTLS_ECP_DP_BP512R1_ENABLED */
+    }
+
+     return( -1 );
+}
+
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH 1
+
+#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 192 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 192 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP192R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 224 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 224 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP224R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP256R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 384 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 384 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP384R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 521 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 521 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP521R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 192 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 192 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 224 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 224 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 256 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_BP256R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 384 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 384 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_BP384R1_ENABLED */
+
+#if defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
+#if MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH < ( 2 * ( ( 512 + 7 ) / 8 ) + 1 )
+#undef MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH
+#define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH ( 2 * ( ( 512 + 7 ) / 8 ) + 1 )
+#endif
+#endif /* MBEDTLS_ECP_DP_BP512R1_ENABLED */
+
+
 static inline psa_ecc_curve_t mbedtls_psa_translate_ecc_group( mbedtls_ecp_group_id grpid )
 {
     switch( grpid )
@@ -231,6 +376,24 @@ static inline psa_ecc_curve_t mbedtls_psa_translate_ecc_group( mbedtls_ecp_group
     }
 }
 
+
+#define MBEDTLS_PSA_ECC_KEY_BITS_OF_CURVE( curve )                \
+    ( curve == PSA_ECC_CURVE_SECP192R1        ? 192 :             \
+      curve == PSA_ECC_CURVE_SECP224R1        ? 224 :             \
+      curve == PSA_ECC_CURVE_SECP256R1        ? 256 :             \
+      curve == PSA_ECC_CURVE_SECP384R1        ? 384 :             \
+      curve == PSA_ECC_CURVE_SECP521R1        ? 521 :             \
+      curve == PSA_ECC_CURVE_SECP192K1        ? 192 :             \
+      curve == PSA_ECC_CURVE_SECP224K1        ? 224 :             \
+      curve == PSA_ECC_CURVE_SECP256K1        ? 256 :             \
+      curve == PSA_ECC_CURVE_BRAINPOOL_P256R1 ? 256 :             \
+      curve == PSA_ECC_CURVE_BRAINPOOL_P384R1 ? 384 :             \
+      curve == PSA_ECC_CURVE_BRAINPOOL_P512R1 ? 512 :             \
+      0 )
+
+#define MBEDTLS_PSA_ECC_KEY_BYTES_OF_CURVE( curve )                \
+    ( ( MBEDTLS_PSA_ECC_KEY_BITS_OF_CURVE( curve ) + 7 ) / 8 )
+
 /* Translations for PK layer */
 
 static inline int mbedtls_psa_err_translate_pk( psa_status_t status )
@@ -259,6 +422,61 @@ static inline int mbedtls_psa_err_translate_pk( psa_status_t status )
     }
 }
 
+/* Translations for ECC */
+
+/* This function transforms an ECC group identifier from
+ * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8
+ * into a PSA ECC group identifier. */
+static inline psa_ecc_curve_t mbedtls_psa_parse_tls_ecc_group(
+    uint16_t tls_ecc_grp_reg_id )
+{
+    /* The PSA identifiers are currently aligned with those from
+     * the TLS Supported Groups registry, so no conversion is necessary. */
+    return( (psa_ecc_curve_t) tls_ecc_grp_reg_id );
+}
+
+/* This function takes a buffer holding an EC public key
+ * exported through psa_export_public_key(), and converts
+ * it into an ECPoint structure to be put into a ClientKeyExchange
+ * message in an ECDHE exchange.
+ *
+ * Both the present and the foreseeable future format of EC public keys
+ * used by PSA have the ECPoint structure contained in the exported key
+ * as a subbuffer, and the function merely selects this subbuffer instead
+ * of making a copy.
+ */
+static inline int mbedtls_psa_tls_psa_ec_to_ecpoint( unsigned char *src,
+                                                     size_t srclen,
+                                                     unsigned char **dst,
+                                                     size_t *dstlen )
+{
+    *dst = src;
+    *dstlen = srclen;
+    return( 0 );
+}
+
+/* This function takes a buffer holding an ECPoint structure
+ * (as contained in a TLS ServerKeyExchange message for ECDHE
+ * exchanges) and converts it into a format that the PSA key
+ * agreement API understands.
+ */
+static inline int mbedtls_psa_tls_ecpoint_to_psa_ec( psa_ecc_curve_t curve,
+                                                     unsigned char const *src,
+                                                     size_t srclen,
+                                                     unsigned char *dst,
+                                                     size_t dstlen,
+                                                     size_t *olen )
+{
+    ((void) curve);
+
+    if( srclen > dstlen )
+        return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
+
+    memcpy( dst, src, srclen );
+    *olen = srclen;
+    return( 0 );
+}
+
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
 #endif /* MBEDTLS_PSA_UTIL_H */
diff --git a/features/mbedtls/inc/mbedtls/ripemd160.h b/features/mbedtls/inc/mbedtls/ripemd160.h
index c74b7d2c6c..b42f6d2a95 100644
--- a/features/mbedtls/inc/mbedtls/ripemd160.h
+++ b/features/mbedtls/inc/mbedtls/ripemd160.h
@@ -219,6 +219,8 @@ MBEDTLS_DEPRECATED void mbedtls_ripemd160( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -226,6 +228,8 @@ MBEDTLS_DEPRECATED void mbedtls_ripemd160( const unsigned char *input,
  */
 int mbedtls_ripemd160_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/rsa.h b/features/mbedtls/inc/mbedtls/rsa.h
index 406a317d4f..489f2ed451 100644
--- a/features/mbedtls/inc/mbedtls/rsa.h
+++ b/features/mbedtls/inc/mbedtls/rsa.h
@@ -150,23 +150,24 @@ mbedtls_rsa_context;
  * \note           The choice of padding mode is strictly enforced for private key
  *                 operations, since there might be security concerns in
  *                 mixing padding modes. For public key operations it is
- *                 a default value, which can be overriden by calling specific
+ *                 a default value, which can be overridden by calling specific
  *                 \c rsa_rsaes_xxx or \c rsa_rsassa_xxx functions.
  *
  * \note           The hash selected in \p hash_id is always used for OEAP
  *                 encryption. For PSS signatures, it is always used for
- *                 making signatures, but can be overriden for verifying them.
- *                 If set to #MBEDTLS_MD_NONE, it is always overriden.
+ *                 making signatures, but can be overridden for verifying them.
+ *                 If set to #MBEDTLS_MD_NONE, it is always overridden.
  *
- * \param ctx      The RSA context to initialize.
- * \param padding  Selects padding mode: #MBEDTLS_RSA_PKCS_V15 or
- *                 #MBEDTLS_RSA_PKCS_V21.
- * \param hash_id  The hash identifier of #mbedtls_md_type_t type, if
- *                 \p padding is #MBEDTLS_RSA_PKCS_V21.
+ * \param ctx      The RSA context to initialize. This must not be \c NULL.
+ * \param padding  The padding mode to use. This must be either
+ *                 #MBEDTLS_RSA_PKCS_V15 or #MBEDTLS_RSA_PKCS_V21.
+ * \param hash_id  The hash identifier of ::mbedtls_md_type_t type, if
+ *                 \p padding is #MBEDTLS_RSA_PKCS_V21. It is unused
+ *                 otherwise.
  */
 void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
                        int padding,
-                       int hash_id);
+                       int hash_id );
 
 /**
  * \brief          This function imports a set of core parameters into an
@@ -188,11 +189,11 @@ void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
  *                 for the lifetime of the RSA context being set up.
  *
  * \param ctx      The initialized RSA context to store the parameters in.
- * \param N        The RSA modulus, or NULL.
- * \param P        The first prime factor of \p N, or NULL.
- * \param Q        The second prime factor of \p N, or NULL.
- * \param D        The private exponent, or NULL.
- * \param E        The public exponent, or NULL.
+ * \param N        The RSA modulus. This may be \c NULL.
+ * \param P        The first prime factor of \p N. This may be \c NULL.
+ * \param Q        The second prime factor of \p N. This may be \c NULL.
+ * \param D        The private exponent. This may be \c NULL.
+ * \param E        The public exponent. This may be \c NULL.
  *
  * \return         \c 0 on success.
  * \return         A non-zero error code on failure.
@@ -222,16 +223,16 @@ int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
  *                 for the lifetime of the RSA context being set up.
  *
  * \param ctx      The initialized RSA context to store the parameters in.
- * \param N        The RSA modulus, or NULL.
- * \param N_len    The Byte length of \p N, ignored if \p N == NULL.
- * \param P        The first prime factor of \p N, or NULL.
- * \param P_len    The Byte length of \p P, ignored if \p P == NULL.
- * \param Q        The second prime factor of \p N, or NULL.
- * \param Q_len    The Byte length of \p Q, ignored if \p Q == NULL.
- * \param D        The private exponent, or NULL.
- * \param D_len    The Byte length of \p D, ignored if \p D == NULL.
- * \param E        The public exponent, or NULL.
- * \param E_len    The Byte length of \p E, ignored if \p E == NULL.
+ * \param N        The RSA modulus. This may be \c NULL.
+ * \param N_len    The Byte length of \p N; it is ignored if \p N == NULL.
+ * \param P        The first prime factor of \p N. This may be \c NULL.
+ * \param P_len    The Byte length of \p P; it ns ignored if \p P == NULL.
+ * \param Q        The second prime factor of \p N. This may be \c NULL.
+ * \param Q_len    The Byte length of \p Q; it is ignored if \p Q == NULL.
+ * \param D        The private exponent. This may be \c NULL.
+ * \param D_len    The Byte length of \p D; it is ignored if \p D == NULL.
+ * \param E        The public exponent. This may be \c NULL.
+ * \param E_len    The Byte length of \p E; it is ignored if \p E == NULL.
  *
  * \return         \c 0 on success.
  * \return         A non-zero error code on failure.
@@ -299,11 +300,16 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx );
  *                 the RSA context stays intact and remains usable.
  *
  * \param ctx      The initialized RSA context.
- * \param N        The MPI to hold the RSA modulus, or NULL.
- * \param P        The MPI to hold the first prime factor of \p N, or NULL.
- * \param Q        The MPI to hold the second prime factor of \p N, or NULL.
- * \param D        The MPI to hold the private exponent, or NULL.
- * \param E        The MPI to hold the public exponent, or NULL.
+ * \param N        The MPI to hold the RSA modulus.
+ *                 This may be \c NULL if this field need not be exported.
+ * \param P        The MPI to hold the first prime factor of \p N.
+ *                 This may be \c NULL if this field need not be exported.
+ * \param Q        The MPI to hold the second prime factor of \p N.
+ *                 This may be \c NULL if this field need not be exported.
+ * \param D        The MPI to hold the private exponent.
+ *                 This may be \c NULL if this field need not be exported.
+ * \param E        The MPI to hold the public exponent.
+ *                 This may be \c NULL if this field need not be exported.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED if exporting the
@@ -341,17 +347,20 @@ int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
  *                 buffer pointers are NULL.
  *
  * \param ctx      The initialized RSA context.
- * \param N        The Byte array to store the RSA modulus, or NULL.
+ * \param N        The Byte array to store the RSA modulus,
+ *                 or \c NULL if this field need not be exported.
  * \param N_len    The size of the buffer for the modulus.
- * \param P        The Byte array to hold the first prime factor of \p N, or
- *                 NULL.
+ * \param P        The Byte array to hold the first prime factor of \p N,
+ *                 or \c NULL if this field need not be exported.
  * \param P_len    The size of the buffer for the first prime factor.
- * \param Q        The Byte array to hold the second prime factor of \p N, or
- *                 NULL.
+ * \param Q        The Byte array to hold the second prime factor of \p N,
+ *                 or \c NULL if this field need not be exported.
  * \param Q_len    The size of the buffer for the second prime factor.
- * \param D        The Byte array to hold the private exponent, or NULL.
+ * \param D        The Byte array to hold the private exponent,
+ *                 or \c NULL if this field need not be exported.
  * \param D_len    The size of the buffer for the private exponent.
- * \param E        The Byte array to hold the public exponent, or NULL.
+ * \param E        The Byte array to hold the public exponent,
+ *                 or \c NULL if this field need not be exported.
  * \param E_len    The size of the buffer for the public exponent.
  *
  * \return         \c 0 on success.
@@ -375,9 +384,12 @@ int mbedtls_rsa_export_raw( const mbedtls_rsa_context *ctx,
  *                 mbedtls_rsa_deduce_opt().
  *
  * \param ctx      The initialized RSA context.
- * \param DP       The MPI to hold D modulo P-1, or NULL.
- * \param DQ       The MPI to hold D modulo Q-1, or NULL.
- * \param QP       The MPI to hold modular inverse of Q modulo P, or NULL.
+ * \param DP       The MPI to hold \c D modulo `P-1`,
+ *                 or \c NULL if it need not be exported.
+ * \param DQ       The MPI to hold \c D modulo `Q-1`,
+ *                 or \c NULL if it need not be exported.
+ * \param QP       The MPI to hold modular inverse of \c Q modulo \c P,
+ *                 or \c NULL if it need not be exported.
  *
  * \return         \c 0 on success.
  * \return         A non-zero error code on failure.
@@ -390,13 +402,13 @@ int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
  * \brief          This function sets padding for an already initialized RSA
  *                 context. See mbedtls_rsa_init() for details.
  *
- * \param ctx      The RSA context to be set.
- * \param padding  Selects padding mode: #MBEDTLS_RSA_PKCS_V15 or
- *                 #MBEDTLS_RSA_PKCS_V21.
+ * \param ctx      The initialized RSA context to be configured.
+ * \param padding  The padding mode to use. This must be either
+ *                 #MBEDTLS_RSA_PKCS_V15 or #MBEDTLS_RSA_PKCS_V21.
  * \param hash_id  The #MBEDTLS_RSA_PKCS_V21 hash identifier.
  */
 void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding,
-                              int hash_id);
+                              int hash_id );
 
 /**
  * \brief          This function retrieves the length of RSA modulus in Bytes.
@@ -414,11 +426,14 @@ size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx );
  * \note           mbedtls_rsa_init() must be called before this function,
  *                 to set up the RSA context.
  *
- * \param ctx      The RSA context used to hold the key.
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param ctx      The initialized RSA context used to hold the key.
+ * \param f_rng    The RNG function to be used for key generation.
+ *                 This must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng.
+ *                 This may be \c NULL if \p f_rng doesn't need a context.
  * \param nbits    The size of the public key in bits.
- * \param exponent The public exponent. For example, 65537.
+ * \param exponent The public exponent to use. For example, \c 65537.
+ *                 This must be odd and greater than \c 1.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -436,7 +451,7 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
  *                 enough information is present to perform an RSA public key
  *                 operation using mbedtls_rsa_public().
  *
- * \param ctx      The RSA context to check.
+ * \param ctx      The initialized RSA context to check.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -475,7 +490,7 @@ int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx );
  *             parameters, which goes beyond what is effectively checkable
  *             by the library.</li></ul>
  *
- * \param ctx  The RSA context to check.
+ * \param ctx  The initialized RSA context to check.
  *
  * \return     \c 0 on success.
  * \return     An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -487,8 +502,8 @@ int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx );
  *
  *                 It checks each of the contexts, and makes sure they match.
  *
- * \param pub      The RSA context holding the public key.
- * \param prv      The RSA context holding the private key.
+ * \param pub      The initialized RSA context holding the public key.
+ * \param prv      The initialized RSA context holding the private key.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -499,18 +514,19 @@ int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub,
 /**
  * \brief          This function performs an RSA public key operation.
  *
+ * \param ctx      The initialized RSA context to use.
+ * \param input    The input buffer. This must be a readable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
+ * \param output   The output buffer. This must be a writable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
+ *
  * \note           This function does not handle message padding.
  *
  * \note           Make sure to set \p input[0] = 0 or ensure that
  *                 input is smaller than \p N.
  *
- * \note           The input and output buffers must be large
- *                 enough. For example, 128 Bytes if RSA-1024 is used.
- *
- * \param ctx      The RSA context.
- * \param input    The input buffer.
- * \param output   The output buffer.
- *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
  */
@@ -521,9 +537,6 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
 /**
  * \brief          This function performs an RSA private key operation.
  *
- * \note           The input and output buffers must be large
- *                 enough. For example, 128 Bytes if RSA-1024 is used.
- *
  * \note           Blinding is used if and only if a PRNG is provided.
  *
  * \note           If blinding is used, both the base of exponentation
@@ -535,11 +548,18 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
  *                 Future versions of the library may enforce the presence
  *                 of a PRNG.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Needed for blinding.
- * \param p_rng    The RNG context.
- * \param input    The input buffer.
- * \param output   The output buffer.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function, used for blinding. It is discouraged
+ *                 and deprecated to pass \c NULL here, in which case
+ *                 blinding will be omitted.
+ * \param p_rng    The RNG context to pass to \p f_rng. This may be \c NULL
+ *                 if \p f_rng is \c NULL or if \p f_rng doesn't need a context.
+ * \param input    The input buffer. This must be a readable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
+ * \param output   The output buffer. This must be a writable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -558,9 +578,6 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
  *                 It is the generic wrapper for performing a PKCS#1 encryption
  *                 operation using the \p mode from the context.
  *
- * \note           The input and output buffers must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -570,14 +587,25 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Needed for padding, PKCS#1 v2.1
- *                 encoding, and #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
- * \param ilen     The length of the plaintext.
- * \param input    The buffer holding the data to encrypt.
- * \param output   The buffer used to hold the ciphertext.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG to use. It is mandatory for PKCS#1 v2.1 padding
+ *                 encoding, and for PKCS#1 v1.5 padding encoding when used
+ *                 with \p mode set to #MBEDTLS_RSA_PUBLIC. For PKCS#1 v1.5
+ *                 padding encoding and \p mode set to #MBEDTLS_RSA_PRIVATE,
+ *                 it is used for blinding and should be provided in this
+ *                 case; see mbedtls_rsa_private() for more.
+ * \param p_rng    The RNG context to be passed to \p f_rng. May be
+ *                 \c NULL if \p f_rng is \c NULL or if \p f_rng doesn't
+ *                 need a context argument.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
+ * \param ilen     The length of the plaintext in Bytes.
+ * \param input    The input data to encrypt. This must be a readable
+ *                 buffer of size \p ilen Bytes. It may be \c NULL if
+ *                 `ilen == 0`.
+ * \param output   The output buffer. This must be a writable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -593,9 +621,6 @@ int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
  * \brief          This function performs a PKCS#1 v1.5 encryption operation
  *                 (RSAES-PKCS1-v1_5-ENCRYPT).
  *
- * \note           The output buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -605,14 +630,23 @@ int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Needed for padding and
- *                 #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
- * \param ilen     The length of the plaintext.
- * \param input    The buffer holding the data to encrypt.
- * \param output   The buffer used to hold the ciphertext.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function to use. It is needed for padding generation
+ *                 if \p mode is #MBEDTLS_RSA_PUBLIC. If \p mode is
+ *                 #MBEDTLS_RSA_PRIVATE (discouraged), it is used for
+ *                 blinding and should be provided; see mbedtls_rsa_private().
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may
+ *                 be \c NULL if \p f_rng is \c NULL or if \p f_rng
+ *                 doesn't need a context argument.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
+ * \param ilen     The length of the plaintext in Bytes.
+ * \param input    The input data to encrypt. This must be a readable
+ *                 buffer of size \p ilen Bytes. It may be \c NULL if
+ *                 `ilen == 0`.
+ * \param output   The output buffer. This must be a writable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -640,16 +674,24 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
  *                   mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                   return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx        The RSA context.
- * \param f_rng      The RNG function. Needed for padding and PKCS#1 v2.1
- *                   encoding and #MBEDTLS_RSA_PRIVATE.
- * \param p_rng      The RNG context.
- * \param mode       #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx        The initnialized RSA context to use.
+ * \param f_rng      The RNG function to use. This is needed for padding
+ *                   generation and must be provided.
+ * \param p_rng      The RNG context to be passed to \p f_rng. This may
+ *                   be \c NULL if \p f_rng doesn't need a context argument.
+ * \param mode       The mode of operation. This must be either
+ *                   #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
  * \param label      The buffer holding the custom label to use.
- * \param label_len  The length of the label.
- * \param ilen       The length of the plaintext.
- * \param input      The buffer holding the data to encrypt.
- * \param output     The buffer used to hold the ciphertext.
+ *                   This must be a readable buffer of length \p label_len
+ *                   Bytes. It may be \c NULL if \p label_len is \c 0.
+ * \param label_len  The length of the label in Bytes.
+ * \param ilen       The length of the plaintext buffer \p input in Bytes.
+ * \param input      The input data to encrypt. This must be a readable
+ *                   buffer of size \p ilen Bytes. It may be \c NULL if
+ *                   `ilen == 0`.
+ * \param output     The output buffer. This must be a writable buffer
+ *                   of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                   for an 2048-bit RSA modulus.
  *
  * \return           \c 0 on success.
  * \return           An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -677,9 +719,6 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
  *                 hold the decryption of the particular ciphertext provided,
  *                 the function returns \c MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE.
  *
- * \note           The input buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -689,14 +728,23 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
- * \param olen     The length of the plaintext.
- * \param input    The buffer holding the encrypted data.
- * \param output   The buffer used to hold the plaintext.
- * \param output_max_len    The maximum length of the output buffer.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. If \p mode is
+ *                 #MBEDTLS_RSA_PUBLIC, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
+ * \param olen     The address at which to store the length of
+ *                 the plaintext. This must not be \c NULL.
+ * \param input    The ciphertext buffer. This must be a readable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
+ * \param output   The buffer used to hold the plaintext. This must
+ *                 be a writable buffer of length \p output_max_len Bytes.
+ * \param output_max_len The length in Bytes of the output buffer \p output.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -720,9 +768,6 @@ int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
  *                 hold the decryption of the particular ciphertext provided,
  *                 the function returns #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE.
  *
- * \note           The input buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -732,14 +777,23 @@ int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
- * \param olen     The length of the plaintext.
- * \param input    The buffer holding the encrypted data.
- * \param output   The buffer to hold the plaintext.
- * \param output_max_len    The maximum length of the output buffer.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. If \p mode is
+ *                 #MBEDTLS_RSA_PUBLIC, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
+ * \param olen     The address at which to store the length of
+ *                 the plaintext. This must not be \c NULL.
+ * \param input    The ciphertext buffer. This must be a readable buffer
+ *                 of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
+ * \param output   The buffer used to hold the plaintext. This must
+ *                 be a writable buffer of length \p output_max_len Bytes.
+ * \param output_max_len The length in Bytes of the output buffer \p output.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -765,9 +819,6 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
  *                   ciphertext provided, the function returns
  *                   #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE.
  *
- * \note             The input buffer must be as large as the size
- *                   of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated       It is deprecated and discouraged to call this function
  *                   in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library
  *                   are likely to remove the \p mode argument and have it
@@ -777,16 +828,27 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
  *                   mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                   return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx        The RSA context.
- * \param f_rng      The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng      The RNG context.
- * \param mode       #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx        The initialized RSA context to use.
+ * \param f_rng      The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                   this is used for blinding and should be provided; see
+ *                   mbedtls_rsa_private() for more. If \p mode is
+ *                   #MBEDTLS_RSA_PUBLIC, it is ignored.
+ * \param p_rng      The RNG context to be passed to \p f_rng. This may be
+ *                   \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode       The mode of operation. This must be either
+ *                   #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
  * \param label      The buffer holding the custom label to use.
- * \param label_len  The length of the label.
- * \param olen       The length of the plaintext.
- * \param input      The buffer holding the encrypted data.
- * \param output     The buffer to hold the plaintext.
- * \param output_max_len    The maximum length of the output buffer.
+ *                   This must be a readable buffer of length \p label_len
+ *                   Bytes. It may be \c NULL if \p label_len is \c 0.
+ * \param label_len  The length of the label in Bytes.
+ * \param olen       The address at which to store the length of
+ *                   the plaintext. This must not be \c NULL.
+ * \param input      The ciphertext buffer. This must be a readable buffer
+ *                   of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                   for an 2048-bit RSA modulus.
+ * \param output     The buffer used to hold the plaintext. This must
+ *                   be a writable buffer of length \p output_max_len Bytes.
+ * \param output_max_len The length in Bytes of the output buffer \p output.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -824,16 +886,28 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Needed for PKCS#1 v2.1 encoding and for
- *                 #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function to use. If the padding mode is PKCS#1 v2.1,
+ *                 this must be provided. If the padding mode is PKCS#1 v1.5 and
+ *                 \p mode is #MBEDTLS_RSA_PRIVATE, it is used for blinding
+ *                 and should be provided; see mbedtls_rsa_private() for more
+ *                 more. It is ignored otherwise.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL
+ *                 if \p f_rng is \c NULL or doesn't need a context argument.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer to hold the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer to hold the signature. This must be a writable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the signing operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -851,9 +925,6 @@ int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
  * \brief          This function performs a PKCS#1 v1.5 signature
  *                 operation (RSASSA-PKCS1-v1_5-SIGN).
  *
- * \note           The \p sig buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -863,15 +934,27 @@ int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. If \p mode is
+ *                 #MBEDTLS_RSA_PUBLIC, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL
+ *                 if \p f_rng is \c NULL or doesn't need a context argument.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer to hold the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer to hold the signature. This must be a writable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the signing operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -889,9 +972,6 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
  * \brief          This function performs a PKCS#1 v2.1 PSS signature
  *                 operation (RSASSA-PSS-SIGN).
  *
- * \note           The \p sig buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \note           The \p hash_id in the RSA context is the one used for the
  *                 encoding. \p md_alg in the function call is the type of hash
  *                 that is encoded. According to <em>RFC-3447: Public-Key
@@ -918,16 +998,24 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA context.
- * \param f_rng    The RNG function. Needed for PKCS#1 v2.1 encoding and for
- *                 #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA context to use.
+ * \param f_rng    The RNG function. It must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL
+ *                 if \p f_rng doesn't need a context argument.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer to hold the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer to hold the signature. This must be a writable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the signing operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -948,9 +1036,6 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
  *                 This is the generic wrapper for performing a PKCS#1
  *                 verification using the mode from the context.
  *
- * \note           The \p sig buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \note           For PKCS#1 v2.1 encoding, see comments on
  *                 mbedtls_rsa_rsassa_pss_verify() about \p md_alg and
  *                 \p hash_id.
@@ -964,15 +1049,26 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA public key context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA public key context to use.
+ * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. Otherwise, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer holding the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer holding the signature. This must be a readable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the verify operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -990,9 +1086,6 @@ int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
  * \brief          This function performs a PKCS#1 v1.5 verification
  *                 operation (RSASSA-PKCS1-v1_5-VERIFY).
  *
- * \note           The \p sig buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \deprecated     It is deprecated and discouraged to call this function
  *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library
  *                 are likely to remove the \p mode argument and have it
@@ -1002,15 +1095,26 @@ int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA public key context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA public key context to use.
+ * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. Otherwise, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer holding the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer holding the signature. This must be a readable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the verify operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -1031,9 +1135,6 @@ int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
  *                 The hash function for the MGF mask generating function
  *                 is that specified in the RSA context.
  *
- * \note           The \p sig buffer must be as large as the size
- *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used.
- *
  * \note           The \p hash_id in the RSA context is the one used for the
  *                 verification. \p md_alg in the function call is the type of
  *                 hash that is verified. According to <em>RFC-3447: Public-Key
@@ -1051,15 +1152,26 @@ int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
  *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx      The RSA public key context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA public key context to use.
+ * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. Otherwise, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param sig      The buffer holding the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param sig      The buffer holding the signature. This must be a readable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the verify operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -1085,19 +1197,29 @@ int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx,
  *
  * \note           The \p hash_id in the RSA context is ignored.
  *
- * \param ctx      The RSA public key context.
- * \param f_rng    The RNG function. Only needed for #MBEDTLS_RSA_PRIVATE.
- * \param p_rng    The RNG context.
- * \param mode     #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
+ * \param ctx      The initialized RSA public key context to use.
+ * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE,
+ *                 this is used for blinding and should be provided; see
+ *                 mbedtls_rsa_private() for more. Otherwise, it is ignored.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng is \c NULL or doesn't need a context.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE.
  * \param md_alg   The message-digest algorithm used to hash the original data.
  *                 Use #MBEDTLS_MD_NONE for signing raw data.
- * \param hashlen  The length of the message digest. Only used if \p md_alg is
- *                 #MBEDTLS_MD_NONE.
- * \param hash     The buffer holding the message digest.
- * \param mgf1_hash_id       The message digest used for mask generation.
- * \param expected_salt_len  The length of the salt used in padding. Use
- *                           #MBEDTLS_RSA_SALT_LEN_ANY to accept any salt length.
- * \param sig      The buffer holding the ciphertext.
+ * \param hashlen  The length of the message digest.
+ *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE.
+ * \param hash     The buffer holding the message digest or raw data.
+ *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable
+ *                 buffer of length \p hashlen Bytes. If \p md_alg is not
+ *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length
+ *                 the size of the hash corresponding to \p md_alg.
+ * \param mgf1_hash_id      The message digest used for mask generation.
+ * \param expected_salt_len The length of the salt used in padding. Use
+ *                          #MBEDTLS_RSA_SALT_LEN_ANY to accept any salt length.
+ * \param sig      The buffer holding the signature. This must be a readable
+ *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes
+ *                 for an 2048-bit RSA modulus.
  *
  * \return         \c 0 if the verify operation was successful.
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
@@ -1116,8 +1238,8 @@ int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
 /**
  * \brief          This function copies the components of an RSA context.
  *
- * \param dst      The destination context.
- * \param src      The source context.
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The source context. This must be initialized.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory allocation failure.
@@ -1127,10 +1249,14 @@ int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
 /**
  * \brief          This function frees the components of an RSA key.
  *
- * \param ctx      The RSA Context to free.
+ * \param ctx      The RSA context to free. May be \c NULL, in which case
+ *                 this function is a no-op. If it is not \c NULL, it must
+ *                 point to an initialized RSA context.
  */
 void mbedtls_rsa_free( mbedtls_rsa_context *ctx );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The RSA checkup routine.
  *
@@ -1139,6 +1265,8 @@ void mbedtls_rsa_free( mbedtls_rsa_context *ctx );
  */
 int mbedtls_rsa_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/sha1.h b/features/mbedtls/inc/mbedtls/sha1.h
index bcaeab5eb9..bb6ecf05a4 100644
--- a/features/mbedtls/inc/mbedtls/sha1.h
+++ b/features/mbedtls/inc/mbedtls/sha1.h
@@ -42,6 +42,7 @@
 
 /* MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED                  -0x0035  /**< SHA-1 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA1_BAD_INPUT_DATA                   -0x0073  /**< SHA-1 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -79,6 +80,7 @@ mbedtls_sha1_context;
  *                 stronger message digests instead.
  *
  * \param ctx      The SHA-1 context to initialize.
+ *                 This must not be \c NULL.
  *
  */
 void mbedtls_sha1_init( mbedtls_sha1_context *ctx );
@@ -90,7 +92,10 @@ void mbedtls_sha1_init( mbedtls_sha1_context *ctx );
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context to clear.
+ * \param ctx      The SHA-1 context to clear. This may be \c NULL,
+ *                 in which case this function does nothing. If it is
+ *                 not \c NULL, it must point to an initialized
+ *                 SHA-1 context.
  *
  */
 void mbedtls_sha1_free( mbedtls_sha1_context *ctx );
@@ -102,8 +107,8 @@ void mbedtls_sha1_free( mbedtls_sha1_context *ctx );
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param dst      The SHA-1 context to clone to.
- * \param src      The SHA-1 context to clone from.
+ * \param dst      The SHA-1 context to clone to. This must be initialized.
+ * \param src      The SHA-1 context to clone from. This must be initialized.
  *
  */
 void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
@@ -116,9 +121,10 @@ void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context to initialize.
+ * \param ctx      The SHA-1 context to initialize. This must be initialized.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_sha1_starts_ret( mbedtls_sha1_context *ctx );
@@ -131,11 +137,14 @@ int mbedtls_sha1_starts_ret( mbedtls_sha1_context *ctx );
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized
+ *                 and have a hash operation started.
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha1_update_ret( mbedtls_sha1_context *ctx,
                              const unsigned char *input,
@@ -149,10 +158,13 @@ int mbedtls_sha1_update_ret( mbedtls_sha1_context *ctx,
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
- * \param output   The SHA-1 checksum result.
+ * \param ctx      The SHA-1 context to use. This must be initialized and
+ *                 have a hash operation started.
+ * \param output   The SHA-1 checksum result. This must be a writable
+ *                 buffer of length \c 20 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha1_finish_ret( mbedtls_sha1_context *ctx,
                              unsigned char output[20] );
@@ -164,10 +176,12 @@ int mbedtls_sha1_finish_ret( mbedtls_sha1_context *ctx,
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
- * \param data     The data block being processed.
+ * \param ctx      The SHA-1 context to use. This must be initialized.
+ * \param data     The data block being processed. This must be a
+ *                 readable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
@@ -188,7 +202,7 @@ int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha1_starts_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context to initialize.
+ * \param ctx      The SHA-1 context to initialize. This must be initialized.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_starts( mbedtls_sha1_context *ctx );
@@ -203,9 +217,11 @@ MBEDTLS_DEPRECATED void mbedtls_sha1_starts( mbedtls_sha1_context *ctx );
  *
  * \deprecated     Superseded by mbedtls_sha1_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized and
+ *                 have a hash operation started.
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_update( mbedtls_sha1_context *ctx,
@@ -222,9 +238,10 @@ MBEDTLS_DEPRECATED void mbedtls_sha1_update( mbedtls_sha1_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha1_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized and
+ *                 have a hash operation started.
  * \param output   The SHA-1 checksum result.
- *
+ *                 This must be a writable buffer of length \c 20 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_finish( mbedtls_sha1_context *ctx,
                                              unsigned char output[20] );
@@ -238,8 +255,9 @@ MBEDTLS_DEPRECATED void mbedtls_sha1_finish( mbedtls_sha1_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_internal_sha1_process() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized.
  * \param data     The data block being processed.
+ *                 This must be a readable buffer of length \c 64 bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_process( mbedtls_sha1_context *ctx,
@@ -262,10 +280,13 @@ MBEDTLS_DEPRECATED void mbedtls_sha1_process( mbedtls_sha1_context *ctx,
  *                 stronger message digests instead.
  *
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  * \param output   The SHA-1 checksum result.
+ *                 This must be a writable buffer of length \c 20 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_sha1_ret( const unsigned char *input,
@@ -294,8 +315,10 @@ int mbedtls_sha1_ret( const unsigned char *input,
  * \deprecated     Superseded by mbedtls_sha1_ret() in 2.7.0
  *
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-1 checksum result.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
+ * \param output   The SHA-1 checksum result. This must be a writable
+ *                 buffer of size \c 20 Bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1( const unsigned char *input,
@@ -305,6 +328,8 @@ MBEDTLS_DEPRECATED void mbedtls_sha1( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The SHA-1 checkup routine.
  *
@@ -318,6 +343,8 @@ MBEDTLS_DEPRECATED void mbedtls_sha1( const unsigned char *input,
  */
 int mbedtls_sha1_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/sha256.h b/features/mbedtls/inc/mbedtls/sha256.h
index 47a31e83af..d64739820c 100644
--- a/features/mbedtls/inc/mbedtls/sha256.h
+++ b/features/mbedtls/inc/mbedtls/sha256.h
@@ -38,6 +38,7 @@
 
 /* MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED                -0x0037  /**< SHA-256 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA256_BAD_INPUT_DATA                 -0x0074  /**< SHA-256 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -71,22 +72,24 @@ mbedtls_sha256_context;
 /**
  * \brief          This function initializes a SHA-256 context.
  *
- * \param ctx      The SHA-256 context to initialize.
+ * \param ctx      The SHA-256 context to initialize. This must not be \c NULL.
  */
 void mbedtls_sha256_init( mbedtls_sha256_context *ctx );
 
 /**
  * \brief          This function clears a SHA-256 context.
  *
- * \param ctx      The SHA-256 context to clear.
+ * \param ctx      The SHA-256 context to clear. This may be \c NULL, in which
+ *                 case this function returns immediately. If it is not \c NULL,
+ *                 it must point to an initialized SHA-256 context.
  */
 void mbedtls_sha256_free( mbedtls_sha256_context *ctx );
 
 /**
  * \brief          This function clones the state of a SHA-256 context.
  *
- * \param dst      The destination context.
- * \param src      The context to clone.
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The context to clone. This must be initialized.
  */
 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src );
@@ -95,11 +98,12 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
  * \brief          This function starts a SHA-224 or SHA-256 checksum
  *                 calculation.
  *
- * \param ctx      The context to initialize.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param ctx      The context to use. This must be initialized.
+ * \param is224    This determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 );
 
@@ -107,11 +111,14 @@ int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 );
  * \brief          This function feeds an input buffer into an ongoing
  *                 SHA-256 checksum calculation.
  *
- * \param ctx      The SHA-256 context.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-256 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
                                const unsigned char *input,
@@ -121,10 +128,13 @@ int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
  * \brief          This function finishes the SHA-256 operation, and writes
  *                 the result to the output buffer.
  *
- * \param ctx      The SHA-256 context.
+ * \param ctx      The SHA-256 context. This must be initialized
+ *                 and have a hash operation started.
  * \param output   The SHA-224 or SHA-256 checksum result.
+ *                 This must be a writable buffer of length \c 32 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                                unsigned char output[32] );
@@ -134,10 +144,12 @@ int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
  *                 the ongoing SHA-256 computation. This function is for
  *                 internal use only.
  *
- * \param ctx      The SHA-256 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-256 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must
+ *                 be a readable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                      const unsigned char data[64] );
@@ -152,12 +164,11 @@ int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
  * \brief          This function starts a SHA-224 or SHA-256 checksum
  *                 calculation.
  *
- *
  * \deprecated     Superseded by mbedtls_sha256_starts_ret() in 2.7.0.
  *
- * \param ctx      The context to initialize.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param ctx      The context to use. This must be initialized.
+ * \param is224    Determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
                                                int is224 );
@@ -168,9 +179,11 @@ MBEDTLS_DEPRECATED void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha256_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-256 context to initialize.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-256 context to use. This must be
+ *                 initialized and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_update( mbedtls_sha256_context *ctx,
                                                const unsigned char *input,
@@ -182,8 +195,10 @@ MBEDTLS_DEPRECATED void mbedtls_sha256_update( mbedtls_sha256_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha256_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-256 context.
- * \param output   The SHA-224 or SHA-256 checksum result.
+ * \param ctx      The SHA-256 context. This must be initialized and
+ *                 have a hash operation started.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must be
+ *                 a writable buffer of length \c 32 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_finish( mbedtls_sha256_context *ctx,
                                                unsigned char output[32] );
@@ -195,8 +210,9 @@ MBEDTLS_DEPRECATED void mbedtls_sha256_finish( mbedtls_sha256_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_internal_sha256_process() in 2.7.0.
  *
- * \param ctx      The SHA-256 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-256 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must be
+ *                 a readable buffer of size \c 64 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_process( mbedtls_sha256_context *ctx,
                                                 const unsigned char data[64] );
@@ -214,11 +230,13 @@ MBEDTLS_DEPRECATED void mbedtls_sha256_process( mbedtls_sha256_context *ctx,
  *                 The SHA-256 result is calculated as
  *                 output = SHA-256(input buffer).
  *
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-224 or SHA-256 checksum result.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must
+ *                 be a writable buffer of length \c 32 Bytes.
+ * \param is224    Determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 int mbedtls_sha256_ret( const unsigned char *input,
                         size_t ilen,
@@ -244,11 +262,13 @@ int mbedtls_sha256_ret( const unsigned char *input,
  *
  * \deprecated     Superseded by mbedtls_sha256_ret() in 2.7.0.
  *
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-224 or SHA-256 checksum result.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must be
+ *                 a writable buffer of length \c 32 Bytes.
+ * \param is224    Determines which function to use. This must be either
+ *                 \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
                                         size_t ilen,
@@ -258,6 +278,8 @@ MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The SHA-224 and SHA-256 checkup routine.
  *
@@ -266,6 +288,8 @@ MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
  */
 int mbedtls_sha256_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/inc/mbedtls/sha512.h b/features/mbedtls/inc/mbedtls/sha512.h
index 020f95de61..c06ceed1d1 100644
--- a/features/mbedtls/inc/mbedtls/sha512.h
+++ b/features/mbedtls/inc/mbedtls/sha512.h
@@ -37,6 +37,7 @@
 
 /* MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED                -0x0039  /**< SHA-512 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA512_BAD_INPUT_DATA                 -0x0075  /**< SHA-512 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -70,22 +71,26 @@ mbedtls_sha512_context;
 /**
  * \brief          This function initializes a SHA-512 context.
  *
- * \param ctx      The SHA-512 context to initialize.
+ * \param ctx      The SHA-512 context to initialize. This must
+ *                 not be \c NULL.
  */
 void mbedtls_sha512_init( mbedtls_sha512_context *ctx );
 
 /**
  * \brief          This function clears a SHA-512 context.
  *
- * \param ctx      The SHA-512 context to clear.
+ * \param ctx      The SHA-512 context to clear. This may be \c NULL,
+ *                 in which case this function does nothing. If it
+ *                 is not \c NULL, it must point to an initialized
+ *                 SHA-512 context.
  */
 void mbedtls_sha512_free( mbedtls_sha512_context *ctx );
 
 /**
  * \brief          This function clones the state of a SHA-512 context.
  *
- * \param dst      The destination context.
- * \param src      The context to clone.
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The context to clone. This must be initialized.
  */
 void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                            const mbedtls_sha512_context *src );
@@ -94,11 +99,12 @@ void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
  * \brief          This function starts a SHA-384 or SHA-512 checksum
  *                 calculation.
  *
- * \param ctx      The SHA-512 context to initialize.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param ctx      The SHA-512 context to use. This must be initialized.
+ * \param is384    Determines which function to use. This must be
+ *                 either \c for SHA-512, or \c 1 for SHA-384.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_starts_ret( mbedtls_sha512_context *ctx, int is384 );
 
@@ -106,11 +112,14 @@ int mbedtls_sha512_starts_ret( mbedtls_sha512_context *ctx, int is384 );
  * \brief          This function feeds an input buffer into an ongoing
  *                 SHA-512 checksum calculation.
  *
- * \param ctx      The SHA-512 context.
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_update_ret( mbedtls_sha512_context *ctx,
                     const unsigned char *input,
@@ -121,10 +130,13 @@ int mbedtls_sha512_update_ret( mbedtls_sha512_context *ctx,
  *                 the result to the output buffer. This function is for
  *                 internal use only.
  *
- * \param ctx      The SHA-512 context.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
  * \param output   The SHA-384 or SHA-512 checksum result.
+ *                 This must be a writable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_finish_ret( mbedtls_sha512_context *ctx,
                                unsigned char output[64] );
@@ -133,10 +145,12 @@ int mbedtls_sha512_finish_ret( mbedtls_sha512_context *ctx,
  * \brief          This function processes a single data block within
  *                 the ongoing SHA-512 computation.
  *
- * \param ctx      The SHA-512 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-512 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This
+ *                 must be a readable buffer of length \c 128 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx,
                                      const unsigned char data[128] );
@@ -152,9 +166,9 @@ int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha512_starts_ret() in 2.7.0
  *
- * \param ctx      The SHA-512 context to initialize.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param ctx      The SHA-512 context to use. This must be initialized.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512 or \c 1 for SHA-384.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_starts( mbedtls_sha512_context *ctx,
                                                int is384 );
@@ -165,9 +179,11 @@ MBEDTLS_DEPRECATED void mbedtls_sha512_starts( mbedtls_sha512_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha512_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_update( mbedtls_sha512_context *ctx,
                                                const unsigned char *input,
@@ -179,8 +195,10 @@ MBEDTLS_DEPRECATED void mbedtls_sha512_update( mbedtls_sha512_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_sha512_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param output   The SHA-384 or SHA-512 checksum result.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param output   The SHA-384 or SHA-512 checksum result. This must
+ *                 be a writable buffer of size \c 64 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_finish( mbedtls_sha512_context *ctx,
                                                unsigned char output[64] );
@@ -192,8 +210,9 @@ MBEDTLS_DEPRECATED void mbedtls_sha512_finish( mbedtls_sha512_context *ctx,
  *
  * \deprecated     Superseded by mbedtls_internal_sha512_process() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-512 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must be
+ *                 a readable buffer of length \c 128 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_process(
                                             mbedtls_sha512_context *ctx,
@@ -212,13 +231,16 @@ MBEDTLS_DEPRECATED void mbedtls_sha512_process(
  *                 The SHA-512 result is calculated as
  *                 output = SHA-512(input buffer).
  *
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ * \param input    The buffer holding the input data. This must be
+ *                 a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-384 or SHA-512 checksum result.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ *                 This must be a writable buffer of length \c 64 Bytes.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_ret( const unsigned char *input,
                         size_t ilen,
@@ -231,6 +253,7 @@ int mbedtls_sha512_ret( const unsigned char *input,
 #else
 #define MBEDTLS_DEPRECATED
 #endif
+
 /**
  * \brief          This function calculates the SHA-512 or SHA-384
  *                 checksum of a buffer.
@@ -243,11 +266,13 @@ int mbedtls_sha512_ret( const unsigned char *input,
  *
  * \deprecated     Superseded by mbedtls_sha512_ret() in 2.7.0
  *
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-384 or SHA-512 checksum result.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param input    The buffer holding the data. This must be a
+ *                 readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-384 or SHA-512 checksum result. This must
+ *                 be a writable buffer of length \c 64 Bytes.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,
                                         size_t ilen,
@@ -256,6 +281,9 @@ MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,
 
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
+
+#if defined(MBEDTLS_SELF_TEST)
+
  /**
  * \brief          The SHA-384 or SHA-512 checkup routine.
  *
@@ -263,6 +291,7 @@ MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,
  * \return         \c 1 on failure.
  */
 int mbedtls_sha512_self_test( int verbose );
+#endif /* MBEDTLS_SELF_TEST */
 
 #ifdef __cplusplus
 }
diff --git a/features/mbedtls/inc/mbedtls/ssl.h b/features/mbedtls/inc/mbedtls/ssl.h
index f7c9d936a9..b793ac04bc 100644
--- a/features/mbedtls/inc/mbedtls/ssl.h
+++ b/features/mbedtls/inc/mbedtls/ssl.h
@@ -787,6 +787,25 @@ typedef int mbedtls_ssl_async_resume_t( mbedtls_ssl_context *ssl,
 typedef void mbedtls_ssl_async_cancel_t( mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
 
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) &&        \
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN  48
+#if defined(MBEDTLS_SHA256_C)
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA256
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN  32
+#elif defined(MBEDTLS_SHA512_C)
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA384
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN  48
+#elif defined(MBEDTLS_SHA1_C)
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA1
+#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN  20
+#else
+/* This is already checked in check_config.h, but be sure. */
+#error "Bad configuration - need SHA-1, SHA-256 or SHA-512 enabled to compute digest of peer CRT."
+#endif
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED &&
+          !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
 /*
  * This structure is used for storing current session data.
  */
@@ -802,7 +821,15 @@ struct mbedtls_ssl_session
     unsigned char master[48];   /*!< the master secret  */
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
-    mbedtls_x509_crt *peer_cert;        /*!< peer X.509 cert chain */
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    mbedtls_x509_crt *peer_cert;       /*!< peer X.509 cert chain */
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    /*! The digest of the peer's end-CRT. This must be kept to detect CRT
+     *  changes during renegotiation, mitigating the triple handshake attack. */
+    unsigned char *peer_cert_digest;
+    size_t peer_cert_digest_len;
+    mbedtls_md_type_t peer_cert_digest_type;
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
     uint32_t verify_result;          /*!<  verification result     */
 
@@ -929,11 +956,11 @@ struct mbedtls_ssl_config
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    psa_key_slot_t psk_opaque; /*!< PSA key slot holding opaque PSK.
-                                *   This field should only be set via
-                                *   mbedtls_ssl_conf_psk_opaque().
-                                *   If either no PSK or a raw PSK have
-                                *   been configured, this has value \c 0. */
+    psa_key_handle_t psk_opaque; /*!< PSA key slot holding opaque PSK.
+                                  *   This field should only be set via
+                                  *   mbedtls_ssl_conf_psk_opaque().
+                                  *   If either no PSK or a raw PSK have
+                                  *   been configured, this has value \c 0. */
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
     unsigned char *psk;      /*!< The raw pre-shared key. This field should
@@ -2055,7 +2082,7 @@ void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf,
  *                 provision more than one cert/key pair (eg one ECDSA, one
  *                 RSA with SHA-256, one RSA with SHA-1). An adequate
  *                 certificate will be selected according to the client's
- *                 advertised capabilities. In case mutliple certificates are
+ *                 advertised capabilities. In case multiple certificates are
  *                 adequate, preference is given to the one set by the first
  *                 call to this function, then second, etc.
  *
@@ -2066,6 +2093,14 @@ void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf,
  *                 whether it matches those preferences - the server can then
  *                 decide what it wants to do with it.
  *
+ * \note           The provided \p pk_key needs to match the public key in the
+ *                 first certificate in \p own_cert, or all handshakes using
+ *                 that certificate will fail. It is your responsibility
+ *                 to ensure that; this function will not perform any check.
+ *                 You may use mbedtls_pk_check_pair() in order to perform
+ *                 this check yourself, but be aware that this function can
+ *                 be computationally expensive on some key types.
+ *
  * \param conf     SSL configuration
  * \param own_cert own public certificate chain
  * \param pk_key   own private key
@@ -2129,7 +2164,7 @@ int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
  * \param psk      The identifier of the key slot holding the PSK.
  *                 Until \p conf is destroyed or this function is successfully
  *                 called again, the key slot \p psk must be populated with a
- *                 key of type #PSA_ALG_CATEGORY_KEY_DERIVATION whose policy
+ *                 key of type PSA_ALG_CATEGORY_KEY_DERIVATION whose policy
  *                 allows its use for the key derivation algorithm applied
  *                 in the handshake.
  * \param psk_identity      The pointer to the pre-shared key identity.
@@ -2144,7 +2179,7 @@ int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
  * \return         An \c MBEDTLS_ERR_SSL_XXX error code on failure.
  */
 int mbedtls_ssl_conf_psk_opaque( mbedtls_ssl_config *conf,
-                                 psa_key_slot_t psk,
+                                 psa_key_handle_t psk,
                                  const unsigned char *psk_identity,
                                  size_t psk_identity_len );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
@@ -2176,7 +2211,7 @@ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
  * \param psk      The identifier of the key slot holding the PSK.
  *                 For the duration of the current handshake, the key slot
  *                 must be populated with a key of type
- *                 #PSA_ALG_CATEGORY_KEY_DERIVATION whose policy allows its
+ *                 PSA_ALG_CATEGORY_KEY_DERIVATION whose policy allows its
  *                 use for the key derivation algorithm
  *                 applied in the handshake.
   *
@@ -2184,7 +2219,7 @@ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
  * \return         An \c MBEDTLS_ERR_SSL_XXX error code on failure.
  */
 int mbedtls_ssl_set_hs_psk_opaque( mbedtls_ssl_context *ssl,
-                                   psa_key_slot_t psk );
+                                   psa_key_handle_t psk );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
 /**
@@ -2964,18 +2999,34 @@ int mbedtls_ssl_get_max_out_record_payload( const mbedtls_ssl_context *ssl );
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 /**
- * \brief          Return the peer certificate from the current connection
+ * \brief          Return the peer certificate from the current connection.
  *
- *                 Note: Can be NULL in case no certificate was sent during
- *                 the handshake. Different calls for the same connection can
- *                 return the same or different pointers for the same
- *                 certificate and even a different certificate altogether.
- *                 The peer cert CAN change in a single connection if
- *                 renegotiation is performed.
+ * \param  ssl     The SSL context to use. This must be initialized and setup.
  *
- * \param ssl      SSL context
+ * \return         The current peer certificate, if available.
+ *                 The returned certificate is owned by the SSL context and
+ *                 is valid only until the next call to the SSL API.
+ * \return         \c NULL if no peer certificate is available. This might
+ *                 be because the chosen ciphersuite doesn't use CRTs
+ *                 (PSK-based ciphersuites, for example), or because
+ *                 #MBEDTLS_SSL_KEEP_PEER_CERTIFICATE has been disabled,
+ *                 allowing the stack to free the peer's CRT to save memory.
  *
- * \return         the current peer certificate
+ * \note           For one-time inspection of the peer's certificate during
+ *                 the handshake, consider registering an X.509 CRT verification
+ *                 callback through mbedtls_ssl_conf_verify() instead of calling
+ *                 this function. Using mbedtls_ssl_conf_verify() also comes at
+ *                 the benefit of allowing you to influence the verification
+ *                 process, for example by masking expected and tolerated
+ *                 verification failures.
+ *
+ * \warning        You must not use the pointer returned by this function
+ *                 after any further call to the SSL API, including
+ *                 mbedtls_ssl_read() and mbedtls_ssl_write(); this is
+ *                 because the pointer might change during renegotiation,
+ *                 which happens transparently to the user.
+ *                 If you want to use the certificate across API calls,
+ *                 you must make a copy.
  */
 const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
@@ -3292,7 +3343,7 @@ void mbedtls_ssl_free( mbedtls_ssl_context *ssl );
  *                 mbedtls_ssl_config_defaults() or mbedtls_ssl_config_free().
  *
  * \note           You need to call mbedtls_ssl_config_defaults() unless you
- *                 manually set all of the relevent fields yourself.
+ *                 manually set all of the relevant fields yourself.
  *
  * \param conf     SSL configuration context
  */
diff --git a/features/mbedtls/inc/mbedtls/ssl_cache.h b/features/mbedtls/inc/mbedtls/ssl_cache.h
index ec081e6d24..84254d3d15 100644
--- a/features/mbedtls/inc/mbedtls/ssl_cache.h
+++ b/features/mbedtls/inc/mbedtls/ssl_cache.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_SSL_CACHE_H
 #define MBEDTLS_SSL_CACHE_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "ssl.h"
 
 #if defined(MBEDTLS_THREADING_C)
@@ -64,7 +70,8 @@ struct mbedtls_ssl_cache_entry
     mbedtls_time_t timestamp;           /*!< entry timestamp    */
 #endif
     mbedtls_ssl_session session;        /*!< entry session      */
-#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     mbedtls_x509_buf peer_cert;         /*!< entry peer_cert    */
 #endif
     mbedtls_ssl_cache_entry *next;      /*!< chain pointer      */
diff --git a/features/mbedtls/inc/mbedtls/ssl_ciphersuites.h b/features/mbedtls/inc/mbedtls/ssl_ciphersuites.h
index cda8b4835b..712678330f 100644
--- a/features/mbedtls/inc/mbedtls/ssl_ciphersuites.h
+++ b/features/mbedtls/inc/mbedtls/ssl_ciphersuites.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_SSL_CIPHERSUITES_H
 #define MBEDTLS_SSL_CIPHERSUITES_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "pk.h"
 #include "cipher.h"
 #include "md.h"
@@ -480,6 +486,24 @@ static inline int mbedtls_ssl_ciphersuite_cert_req_allowed( const mbedtls_ssl_ci
     }
 }
 
+static inline int mbedtls_ssl_ciphersuite_uses_srv_cert( const mbedtls_ssl_ciphersuite_t *info )
+{
+    switch( info->key_exchange )
+    {
+        case MBEDTLS_KEY_EXCHANGE_RSA:
+        case MBEDTLS_KEY_EXCHANGE_RSA_PSK:
+        case MBEDTLS_KEY_EXCHANGE_DHE_RSA:
+        case MBEDTLS_KEY_EXCHANGE_ECDH_RSA:
+        case MBEDTLS_KEY_EXCHANGE_ECDHE_RSA:
+        case MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA:
+        case MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA:
+            return( 1 );
+
+        default:
+            return( 0 );
+    }
+}
+
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__DHE_ENABLED)
 static inline int mbedtls_ssl_ciphersuite_uses_dhe( const mbedtls_ssl_ciphersuite_t *info )
 {
diff --git a/features/mbedtls/inc/mbedtls/ssl_cookie.h b/features/mbedtls/inc/mbedtls/ssl_cookie.h
index 6a0ad4fa96..e34760ae85 100644
--- a/features/mbedtls/inc/mbedtls/ssl_cookie.h
+++ b/features/mbedtls/inc/mbedtls/ssl_cookie.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_SSL_COOKIE_H
 #define MBEDTLS_SSL_COOKIE_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "ssl.h"
 
 #if defined(MBEDTLS_THREADING_C)
diff --git a/features/mbedtls/inc/mbedtls/ssl_internal.h b/features/mbedtls/inc/mbedtls/ssl_internal.h
index 318d13fd84..5dde239dff 100644
--- a/features/mbedtls/inc/mbedtls/ssl_internal.h
+++ b/features/mbedtls/inc/mbedtls/ssl_internal.h
@@ -24,9 +24,19 @@
 #ifndef MBEDTLS_SSL_INTERNAL_H
 #define MBEDTLS_SSL_INTERNAL_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 #include "ssl.h"
 #include "cipher.h"
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "psa/crypto.h"
+#endif
+
 #if defined(MBEDTLS_MD5_C)
 #include "md5.h"
 #endif
@@ -47,6 +57,11 @@
 #include "ecjpake.h"
 #endif
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "psa/crypto.h"
+#include "psa_util.h"
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
 #define inline __inline
@@ -270,7 +285,15 @@ struct mbedtls_ssl_handshake_params
 #endif
 #if defined(MBEDTLS_ECDH_C)
     mbedtls_ecdh_context ecdh_ctx;              /*!<  ECDH key exchange       */
-#endif
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_ecc_curve_t ecdh_psa_curve;
+    psa_key_handle_t ecdh_psa_privkey;
+    unsigned char ecdh_psa_peerkey[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
+    size_t ecdh_psa_peerkey_len;
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_ECDH_C */
+
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
     mbedtls_ecjpake_context ecjpake_ctx;        /*!< EC J-PAKE key exchange */
 #if defined(MBEDTLS_SSL_CLI_C)
@@ -284,7 +307,7 @@ struct mbedtls_ssl_handshake_params
 #endif
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    psa_key_slot_t psk_opaque;          /*!< Opaque PSK from the callback   */
+    psa_key_handle_t psk_opaque;        /*!< Opaque PSK from the callback   */
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
     unsigned char *psk;                 /*!<  PSK from the callback         */
     size_t psk_len;                     /*!<  Length of PSK from callback   */
@@ -308,8 +331,13 @@ struct mbedtls_ssl_handshake_params
         ssl_ecrs_cke_ecdh_calc_secret,  /*!< ClientKeyExchange: ECDH step 2 */
         ssl_ecrs_crt_vrfy_sign,         /*!< CertificateVerify: pk_sign()   */
     } ecrs_state;                       /*!< current (or last) operation    */
+    mbedtls_x509_crt *ecrs_peer_cert;   /*!< The peer's CRT chain.          */
     size_t ecrs_n;                      /*!< place for saving a length      */
 #endif
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    mbedtls_pk_context peer_pubkey;     /*!< The public key from the peer.  */
+#endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     unsigned int out_msg_seq;           /*!<  Outgoing handshake sequence number */
     unsigned int in_msg_seq;            /*!<  Incoming handshake sequence number */
@@ -370,11 +398,19 @@ struct mbedtls_ssl_handshake_params
 #endif
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_operation_t fin_sha256_psa;
+#else
     mbedtls_sha256_context fin_sha256;
 #endif
+#endif
 #if defined(MBEDTLS_SHA512_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_operation_t fin_sha384_psa;
+#else
     mbedtls_sha512_context fin_sha512;
 #endif
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
     void (*update_checksum)(mbedtls_ssl_context *, const unsigned char *, size_t);
@@ -735,6 +771,9 @@ int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl );
 #endif
 
+int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
+                              const mbedtls_ssl_session *src );
+
 /* constant-time buffer comparison */
 static inline int mbedtls_ssl_safer_memcmp( const void *a, const void *b, size_t n )
 {
@@ -765,6 +804,7 @@ int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl,
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
     defined(MBEDTLS_SSL_PROTO_TLS1_2)
+/* The hash buffer must have at least MBEDTLS_MD_MAX_SIZE bytes of length. */
 int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
                                             unsigned char *hash, size_t *hashlen,
                                             unsigned char *data, size_t data_len,
diff --git a/features/mbedtls/inc/mbedtls/ssl_ticket.h b/features/mbedtls/inc/mbedtls/ssl_ticket.h
index b2686df09f..774a007a9f 100644
--- a/features/mbedtls/inc/mbedtls/ssl_ticket.h
+++ b/features/mbedtls/inc/mbedtls/ssl_ticket.h
@@ -24,6 +24,12 @@
 #ifndef MBEDTLS_SSL_TICKET_H
 #define MBEDTLS_SSL_TICKET_H
 
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 /*
  * This implementation of the session ticket callbacks includes key
  * management, rotating the keys periodically in order to preserve forward
@@ -111,14 +117,14 @@ int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
 /**
  * \brief           Implementation of the ticket write callback
  *
- * \note            See \c mbedlts_ssl_ticket_write_t for description
+ * \note            See \c mbedtls_ssl_ticket_write_t for description
  */
 mbedtls_ssl_ticket_write_t mbedtls_ssl_ticket_write;
 
 /**
  * \brief           Implementation of the ticket parse callback
  *
- * \note            See \c mbedlts_ssl_ticket_parse_t for description
+ * \note            See \c mbedtls_ssl_ticket_parse_t for description
  */
 mbedtls_ssl_ticket_parse_t mbedtls_ssl_ticket_parse;
 
diff --git a/features/mbedtls/inc/mbedtls/version.h b/features/mbedtls/inc/mbedtls/version.h
index a9366bb11f..3f2e12ca52 100644
--- a/features/mbedtls/inc/mbedtls/version.h
+++ b/features/mbedtls/inc/mbedtls/version.h
@@ -38,8 +38,8 @@
  * The version number x.y.z is split into three parts.
  * Major, Minor, Patchlevel
  */
-#define MBEDTLS_VERSION_MAJOR  2
-#define MBEDTLS_VERSION_MINOR  15
+#define MBEDTLS_VERSION_MAJOR  0
+#define MBEDTLS_VERSION_MINOR  0
 #define MBEDTLS_VERSION_PATCH  0
 
 /**
@@ -47,9 +47,9 @@
  *    MMNNPP00
  *    Major version | Minor version | Patch version
  */
-#define MBEDTLS_VERSION_NUMBER         0x020F0000
-#define MBEDTLS_VERSION_STRING         "2.15.0"
-#define MBEDTLS_VERSION_STRING_FULL    "mbed TLS 2.15.0"
+#define MBEDTLS_VERSION_NUMBER         0x00000000
+#define MBEDTLS_VERSION_STRING         "0.0.0"
+#define MBEDTLS_VERSION_STRING_FULL    "mbed TLS 0.0.0"
 
 #if defined(MBEDTLS_VERSION_C)
 
diff --git a/features/mbedtls/inc/mbedtls/x509.h b/features/mbedtls/inc/mbedtls/x509.h
index d6db9c6e37..63aae32d87 100644
--- a/features/mbedtls/inc/mbedtls/x509.h
+++ b/features/mbedtls/inc/mbedtls/x509.h
@@ -77,7 +77,7 @@
 #define MBEDTLS_ERR_X509_ALLOC_FAILED                     -0x2880  /**< Allocation of memory failed. */
 #define MBEDTLS_ERR_X509_FILE_IO_ERROR                    -0x2900  /**< Read/write of file failed. */
 #define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL                 -0x2980  /**< Destination buffer is too small. */
-#define MBEDTLS_ERR_X509_FATAL_ERROR                      -0x3000  /**< A fatal error occured, eg the chain is too long or the vrfy callback failed. */
+#define MBEDTLS_ERR_X509_FATAL_ERROR                      -0x3000  /**< A fatal error occurred, eg the chain is too long or the vrfy callback failed. */
 /* \} name */
 
 /**
@@ -250,7 +250,7 @@ int mbedtls_x509_serial_gets( char *buf, size_t size, const mbedtls_x509_buf *se
  *
  * \param to       mbedtls_x509_time to check
  *
- * \return         1 if the given time is in the past or an error occured,
+ * \return         1 if the given time is in the past or an error occurred,
  *                 0 otherwise.
  */
 int mbedtls_x509_time_is_past( const mbedtls_x509_time *to );
@@ -264,11 +264,13 @@ int mbedtls_x509_time_is_past( const mbedtls_x509_time *to );
  *
  * \param from     mbedtls_x509_time to check
  *
- * \return         1 if the given time is in the future or an error occured,
+ * \return         1 if the given time is in the future or an error occurred,
  *                 0 otherwise.
  */
 int mbedtls_x509_time_is_future( const mbedtls_x509_time *from );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -276,6 +278,8 @@ int mbedtls_x509_time_is_future( const mbedtls_x509_time *from );
  */
 int mbedtls_x509_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 /*
  * Internal module functions. You probably do not want to use these unless you
  * know you do.
diff --git a/features/mbedtls/inc/mbedtls/x509_crl.h b/features/mbedtls/inc/mbedtls/x509_crl.h
index 08a4283a67..fa838d68cb 100644
--- a/features/mbedtls/inc/mbedtls/x509_crl.h
+++ b/features/mbedtls/inc/mbedtls/x509_crl.h
@@ -111,7 +111,7 @@ int mbedtls_x509_crl_parse_der( mbedtls_x509_crl *chain,
 /**
  * \brief          Parse one or more CRLs and append them to the chained list
  *
- * \note           Mutliple CRLs are accepted only if using PEM format
+ * \note           Multiple CRLs are accepted only if using PEM format
  *
  * \param chain    points to the start of the chain
  * \param buf      buffer holding the CRL data in PEM or DER format
@@ -126,7 +126,7 @@ int mbedtls_x509_crl_parse( mbedtls_x509_crl *chain, const unsigned char *buf, s
 /**
  * \brief          Load one or more CRLs and append them to the chained list
  *
- * \note           Mutliple CRLs are accepted only if using PEM format
+ * \note           Multiple CRLs are accepted only if using PEM format
  *
  * \param chain    points to the start of the chain
  * \param path     filename to read the CRLs from (in PEM or DER encoding)
diff --git a/features/mbedtls/inc/mbedtls/x509_crt.h b/features/mbedtls/inc/mbedtls/x509_crt.h
index afeefca60e..b3f27be930 100644
--- a/features/mbedtls/inc/mbedtls/x509_crt.h
+++ b/features/mbedtls/inc/mbedtls/x509_crt.h
@@ -52,6 +52,8 @@ extern "C" {
  */
 typedef struct mbedtls_x509_crt
 {
+    int own_buffer;                     /**< Indicates if \c raw is owned
+                                         *   by the structure or not.        */
     mbedtls_x509_buf raw;               /**< The raw certificate data (DER). */
     mbedtls_x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
 
@@ -68,6 +70,7 @@ typedef struct mbedtls_x509_crt
     mbedtls_x509_time valid_from;       /**< Start time of certificate validity. */
     mbedtls_x509_time valid_to;         /**< End time of certificate validity. */
 
+    mbedtls_x509_buf pk_raw;
     mbedtls_pk_context pk;              /**< Container for the public key context. */
 
     mbedtls_x509_buf issuer_id;         /**< Optional X.509 v2/v3 issuer unique identifier. */
@@ -220,31 +223,88 @@ extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
 
 /**
  * \brief          Parse a single DER formatted certificate and add it
- *                 to the chained list.
+ *                 to the end of the provided chained list.
  *
- * \param chain    points to the start of the chain
- * \param buf      buffer holding the certificate DER data
- * \param buflen   size of the buffer
+ * \param chain    The pointer to the start of the CRT chain to attach to.
+ *                 When parsing the first CRT in a chain, this should point
+ *                 to an instance of ::mbedtls_x509_crt initialized through
+ *                 mbedtls_x509_crt_init().
+ * \param buf      The buffer holding the DER encoded certificate.
+ * \param buflen   The size in Bytes of \p buf.
  *
- * \return         0 if successful, or a specific X509 or PEM error code
+ * \note           This function makes an internal copy of the CRT buffer
+ *                 \p buf. In particular, \p buf may be destroyed or reused
+ *                 after this call returns. To avoid duplicating the CRT
+ *                 buffer (at the cost of stricter lifetime constraints),
+ *                 use mbedtls_x509_crt_parse_der_nocopy() instead.
+ *
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
-                        size_t buflen );
+int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain,
+                                const unsigned char *buf,
+                                size_t buflen );
 
 /**
- * \brief          Parse one or more certificates and add them
- *                 to the chained list. Parses permissively. If some
- *                 certificates can be parsed, the result is the number
- *                 of failed certificates it encountered. If none complete
- *                 correctly, the first error is returned.
+ * \brief          Parse a single DER formatted certificate and add it
+ *                 to the end of the provided chained list. This is a
+ *                 variant of mbedtls_x509_crt_parse_der() which takes
+ *                 temporary ownership of the CRT buffer until the CRT
+ *                 is destroyed.
  *
- * \param chain    points to the start of the chain
- * \param buf      buffer holding the certificate data in PEM or DER format
- * \param buflen   size of the buffer
- *                 (including the terminating null byte for PEM data)
+ * \param chain    The pointer to the start of the CRT chain to attach to.
+ *                 When parsing the first CRT in a chain, this should point
+ *                 to an instance of ::mbedtls_x509_crt initialized through
+ *                 mbedtls_x509_crt_init().
+ * \param buf      The address of the readable buffer holding the DER encoded
+ *                 certificate to use. On success, this buffer must be
+ *                 retained and not be changed for the liftetime of the
+ *                 CRT chain \p chain, that is, until \p chain is destroyed
+ *                 through a call to mbedtls_x509_crt_free().
+ * \param buflen   The size in Bytes of \p buf.
+ *
+ * \note           This call is functionally equivalent to
+ *                 mbedtls_x509_crt_parse_der(), but it avoids creating a
+ *                 copy of the input buffer at the cost of stronger lifetime
+ *                 constraints. This is useful in constrained environments
+ *                 where duplication of the CRT cannot be tolerated.
+ *
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
+ */
+int mbedtls_x509_crt_parse_der_nocopy( mbedtls_x509_crt *chain,
+                                       const unsigned char *buf,
+                                       size_t buflen );
+
+/**
+ * \brief          Parse one DER-encoded or one or more concatenated PEM-encoded
+ *                 certificates and add them to the chained list.
+ *
+ *                 For CRTs in PEM encoding, the function parses permissively:
+ *                 if at least one certificate can be parsed, the function
+ *                 returns the number of certificates for which parsing failed
+ *                 (hence \c 0 if all certificates were parsed successfully).
+ *                 If no certificate could be parsed, the function returns
+ *                 the first (negative) error encountered during parsing.
+ *
+ *                 PEM encoded certificates may be interleaved by other data
+ *                 such as human readable descriptions of their content, as
+ *                 long as the certificates are enclosed in the PEM specific
+ *                 '-----{BEGIN/END} CERTIFICATE-----' delimiters.
+ *
+ * \param chain    The chain to which to add the parsed certificates.
+ * \param buf      The buffer holding the certificate data in PEM or DER format.
+ *                 For certificates in PEM encoding, this may be a concatenation
+ *                 of multiple certificates; for DER encoding, the buffer must
+ *                 comprise exactly one certificate.
+ * \param buflen   The size of \p buf, including the terminating \c NULL byte
+ *                 in case of PEM encoded data.
+ *
+ * \return         \c 0 if all certificates were parsed successfully.
+ * \return         The (positive) number of certificates that couldn't
+ *                 be parsed if parsing was partly successful (see above).
+ * \return         A negative X509 or PEM error code otherwise.
  *
- * \return         0 if all certificates parsed successfully, a positive number
- *                 if partly successful or a specific X509 or PEM error code
  */
 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen );
 
diff --git a/features/mbedtls/inc/mbedtls/x509_csr.h b/features/mbedtls/inc/mbedtls/x509_csr.h
index 0c6ccad78d..a3c28048e0 100644
--- a/features/mbedtls/inc/mbedtls/x509_csr.h
+++ b/features/mbedtls/inc/mbedtls/x509_csr.h
@@ -205,6 +205,14 @@ void mbedtls_x509write_csr_set_md_alg( mbedtls_x509write_csr *ctx, mbedtls_md_ty
  * \param key_usage key usage flags to set
  *
  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ *
+ * \note            The <code>decipherOnly</code> flag from the Key Usage
+ *                  extension is represented by bit 8 (i.e.
+ *                  <code>0x8000</code>), which cannot typically be represented
+ *                  in an unsigned char. Therefore, the flag
+ *                  <code>decipherOnly</code> (i.e.
+ *                  #MBEDTLS_X509_KU_DECIPHER_ONLY) cannot be set using this
+ *                  function.
  */
 int mbedtls_x509write_csr_set_key_usage( mbedtls_x509write_csr *ctx, unsigned char key_usage );
 
diff --git a/features/mbedtls/inc/mbedtls/xtea.h b/features/mbedtls/inc/mbedtls/xtea.h
index 6430c1318a..b47f553508 100644
--- a/features/mbedtls/inc/mbedtls/xtea.h
+++ b/features/mbedtls/inc/mbedtls/xtea.h
@@ -121,6 +121,8 @@ int mbedtls_xtea_crypt_cbc( mbedtls_xtea_context *ctx,
                     unsigned char *output);
 #endif /* MBEDTLS_CIPHER_MODE_CBC */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -128,6 +130,8 @@ int mbedtls_xtea_crypt_cbc( mbedtls_xtea_context *ctx,
  */
 int mbedtls_xtea_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/features/mbedtls/platform/inc/platform_mbed.h b/features/mbedtls/platform/inc/platform_mbed.h
index 267b86272d..64179268b4 100644
--- a/features/mbedtls/platform/inc/platform_mbed.h
+++ b/features/mbedtls/platform/inc/platform_mbed.h
@@ -43,6 +43,15 @@
 #include "mbedtls_device.h"
 #endif
 
+#if defined(TARGET_PSA)
+/* The following configurations are a needed for Mbed Crypto submodule.
+ * They are related to the persistent key storage feature.
+ */
+#define MBEDTLS_PSA_CRYPTO_STORAGE_C
+#define MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C
+#undef MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+#endif
+
 /*
  * MBEDTLS_ERR_PLATFORM_HW_FAILED is deprecated and should not be used.
  */
diff --git a/features/mbedtls/src/Makefile b/features/mbedtls/src/Makefile
index f01b1a1502..d10fc41f4a 100644
--- a/features/mbedtls/src/Makefile
+++ b/features/mbedtls/src/Makefile
@@ -39,7 +39,7 @@ SOEXT_TLS=so.12
 SOEXT_X509=so.0
 SOEXT_CRYPTO=so.3
 
-# Set AR_DASH= (empty string) to use an ar implentation that does not accept
+# Set AR_DASH= (empty string) to use an ar implementation that does not accept
 # the - prefix for command line options (e.g. llvm-ar)
 AR_DASH ?= -
 
diff --git a/features/mbedtls/src/aes.c b/features/mbedtls/src/aes.c
index 3de571e693..0543cd7817 100644
--- a/features/mbedtls/src/aes.c
+++ b/features/mbedtls/src/aes.c
@@ -56,6 +56,12 @@
 
 #if !defined(MBEDTLS_AES_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define AES_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_AES_BAD_INPUT_DATA )
+#define AES_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (little endian)
  */
@@ -511,6 +517,8 @@ static void aes_gen_tables( void )
 
 void mbedtls_aes_init( mbedtls_aes_context *ctx )
 {
+    AES_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_aes_context ) );
 }
 
@@ -525,12 +533,17 @@ void mbedtls_aes_free( mbedtls_aes_context *ctx )
 #if defined(MBEDTLS_CIPHER_MODE_XTS)
 void mbedtls_aes_xts_init( mbedtls_aes_xts_context *ctx )
 {
+    AES_VALIDATE( ctx != NULL );
+
     mbedtls_aes_init( &ctx->crypt );
     mbedtls_aes_init( &ctx->tweak );
 }
 
 void mbedtls_aes_xts_free( mbedtls_aes_xts_context *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_aes_free( &ctx->crypt );
     mbedtls_aes_free( &ctx->tweak );
 }
@@ -546,14 +559,8 @@ int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
     unsigned int i;
     uint32_t *RK;
 
-#if !defined(MBEDTLS_AES_ROM_TABLES)
-    if( aes_init_done == 0 )
-    {
-        aes_gen_tables();
-        aes_init_done = 1;
-
-    }
-#endif
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
 
     switch( keybits )
     {
@@ -563,6 +570,14 @@ int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
         default : return( MBEDTLS_ERR_AES_INVALID_KEY_LENGTH );
     }
 
+#if !defined(MBEDTLS_AES_ROM_TABLES)
+    if( aes_init_done == 0 )
+    {
+        aes_gen_tables();
+        aes_init_done = 1;
+    }
+#endif
+
 #if defined(MBEDTLS_PADLOCK_C) && defined(MBEDTLS_PADLOCK_ALIGN16)
     if( aes_padlock_ace == -1 )
         aes_padlock_ace = mbedtls_padlock_has_support( MBEDTLS_PADLOCK_ACE );
@@ -662,6 +677,9 @@ int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
     uint32_t *RK;
     uint32_t *SK;
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
+
     mbedtls_aes_init( &cty );
 
 #if defined(MBEDTLS_PADLOCK_C) && defined(MBEDTLS_PADLOCK_ALIGN16)
@@ -752,6 +770,9 @@ int mbedtls_aes_xts_setkey_enc( mbedtls_aes_xts_context *ctx,
     const unsigned char *key1, *key2;
     unsigned int key1bits, key2bits;
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
+
     ret = mbedtls_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
                                        &key2, &key2bits );
     if( ret != 0 )
@@ -774,6 +795,9 @@ int mbedtls_aes_xts_setkey_dec( mbedtls_aes_xts_context *ctx,
     const unsigned char *key1, *key2;
     unsigned int key1bits, key2bits;
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
+
     ret = mbedtls_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
                                        &key2, &key2bits );
     if( ret != 0 )
@@ -977,10 +1001,16 @@ void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
  * AES-ECB block encryption/decryption
  */
 int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
-                    int mode,
-                    const unsigned char input[16],
-                    unsigned char output[16] )
+                           int mode,
+                           const unsigned char input[16],
+                           unsigned char output[16] )
 {
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+
 #if defined(MBEDTLS_AESNI_C) && defined(MBEDTLS_HAVE_X86_64)
     if( mbedtls_aesni_has_support( MBEDTLS_AESNI_AES ) )
         return( mbedtls_aesni_crypt_ecb( ctx, mode, input, output ) );
@@ -1018,6 +1048,13 @@ int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
     int i;
     unsigned char temp[16];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
     if( length % 16 )
         return( MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
 
@@ -1143,6 +1180,13 @@ int mbedtls_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
     unsigned char prev_tweak[16];
     unsigned char tmp[16];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( data_unit != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
     /* Data units must be at least 16 bytes long. */
     if( length < 16 )
         return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
@@ -1242,7 +1286,20 @@ int mbedtls_aes_crypt_cfb128( mbedtls_aes_context *ctx,
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv_off != NULL );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *iv_off;
+
+    if( n > 15 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_AES_DECRYPT )
     {
@@ -1280,15 +1337,21 @@ int mbedtls_aes_crypt_cfb128( mbedtls_aes_context *ctx,
  * AES-CFB8 buffer encryption/decryption
  */
 int mbedtls_aes_crypt_cfb8( mbedtls_aes_context *ctx,
-                       int mode,
-                       size_t length,
-                       unsigned char iv[16],
-                       const unsigned char *input,
-                       unsigned char *output )
+                            int mode,
+                            size_t length,
+                            unsigned char iv[16],
+                            const unsigned char *input,
+                            unsigned char *output )
 {
     unsigned char c;
     unsigned char ov[17];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
     while( length-- )
     {
         memcpy( ov, iv, 16 );
@@ -1321,7 +1384,18 @@ int mbedtls_aes_crypt_ofb( mbedtls_aes_context *ctx,
                            unsigned char *output )
 {
     int ret = 0;
-    size_t n = *iv_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( iv_off != NULL );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *iv_off;
+
+    if( n > 15 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
 
     while( length-- )
     {
@@ -1356,7 +1430,16 @@ int mbedtls_aes_crypt_ctr( mbedtls_aes_context *ctx,
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( nc_off != NULL );
+    AES_VALIDATE_RET( nonce_counter != NULL );
+    AES_VALIDATE_RET( stream_block != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *nc_off;
 
     if ( n > 0x0F )
         return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
diff --git a/features/mbedtls/src/aria.c b/features/mbedtls/src/aria.c
index ca9e147f0d..aff66d667f 100644
--- a/features/mbedtls/src/aria.c
+++ b/features/mbedtls/src/aria.c
@@ -55,6 +55,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define ARIA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ARIA_BAD_INPUT_DATA )
+#define ARIA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (little endian)
  */
@@ -449,9 +455,11 @@ int mbedtls_aria_setkey_enc( mbedtls_aria_context *ctx,
 
     int i;
     uint32_t w[4][4], *w2;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( key != NULL );
 
     if( keybits != 128 && keybits != 192 && keybits != 256 )
-        return( MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH );
+        return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
 
     /* Copy key to W0 (and potential remainder to W1) */
     GET_UINT32_LE( w[0][0], key,  0 );
@@ -503,6 +511,8 @@ int mbedtls_aria_setkey_dec( mbedtls_aria_context *ctx,
                              const unsigned char *key, unsigned int keybits )
 {
     int i, j, k, ret;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( key != NULL );
 
     ret = mbedtls_aria_setkey_enc( ctx, key, keybits );
     if( ret != 0 )
@@ -539,6 +549,9 @@ int mbedtls_aria_crypt_ecb( mbedtls_aria_context *ctx,
     int i;
 
     uint32_t a, b, c, d;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( input != NULL );
+    ARIA_VALIDATE_RET( output != NULL );
 
     GET_UINT32_LE( a, input,  0 );
     GET_UINT32_LE( b, input,  4 );
@@ -586,6 +599,7 @@ int mbedtls_aria_crypt_ecb( mbedtls_aria_context *ctx,
 /* Initialize context */
 void mbedtls_aria_init( mbedtls_aria_context *ctx )
 {
+    ARIA_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_aria_context ) );
 }
 
@@ -612,6 +626,13 @@ int mbedtls_aria_crypt_cbc( mbedtls_aria_context *ctx,
     int i;
     unsigned char temp[MBEDTLS_ARIA_BLOCKSIZE];
 
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( mode == MBEDTLS_ARIA_ENCRYPT ||
+                       mode == MBEDTLS_ARIA_DECRYPT );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( iv != NULL );
+
     if( length % MBEDTLS_ARIA_BLOCKSIZE )
         return( MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH );
 
@@ -665,7 +686,23 @@ int mbedtls_aria_crypt_cfb128( mbedtls_aria_context *ctx,
                                unsigned char *output )
 {
     unsigned char c;
-    size_t n = *iv_off;
+    size_t n;
+
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( mode == MBEDTLS_ARIA_ENCRYPT ||
+                       mode == MBEDTLS_ARIA_DECRYPT );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( iv != NULL );
+    ARIA_VALIDATE_RET( iv_off != NULL );
+
+    n = *iv_off;
+
+    /* An overly large value of n can lead to an unlimited
+     * buffer overflow. Therefore, guard against this
+     * outside of parameter validation. */
+    if( n >= MBEDTLS_ARIA_BLOCKSIZE )
+        return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_ARIA_DECRYPT )
     {
@@ -713,7 +750,21 @@ int mbedtls_aria_crypt_ctr( mbedtls_aria_context *ctx,
                             unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( nonce_counter != NULL );
+    ARIA_VALIDATE_RET( stream_block  != NULL );
+    ARIA_VALIDATE_RET( nc_off != NULL );
+
+    n = *nc_off;
+    /* An overly large value of n can lead to an unlimited
+     * buffer overflow. Therefore, guard against this
+     * outside of parameter validation. */
+    if( n >= MBEDTLS_ARIA_BLOCKSIZE )
+        return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/features/mbedtls/src/asn1write.c b/features/mbedtls/src/asn1write.c
index d617de5b07..b54e26bd8a 100644
--- a/features/mbedtls/src/asn1write.c
+++ b/features/mbedtls/src/asn1write.c
@@ -290,26 +290,75 @@ int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
     return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len) );
 }
 
+int mbedtls_asn1_write_named_bitstring( unsigned char **p,
+                                        unsigned char *start,
+                                        const unsigned char *buf,
+                                        size_t bits )
+{
+    size_t unused_bits, byte_len;
+    const unsigned char *cur_byte;
+    unsigned char cur_byte_shifted;
+    unsigned char bit;
+
+    byte_len = ( bits + 7 ) / 8;
+    unused_bits = ( byte_len * 8 ) - bits;
+
+    /*
+     * Named bitstrings require that trailing 0s are excluded in the encoding
+     * of the bitstring. Trailing 0s are considered part of the 'unused' bits
+     * when encoding this value in the first content octet
+     */
+    if( bits != 0 )
+    {
+        cur_byte = buf + byte_len - 1;
+        cur_byte_shifted = *cur_byte >> unused_bits;
+
+        for( ; ; )
+        {
+            bit = cur_byte_shifted & 0x1;
+            cur_byte_shifted >>= 1;
+
+            if( bit != 0 )
+                break;
+
+            bits--;
+            if( bits == 0 )
+                break;
+
+            if( bits % 8 == 0 )
+                cur_byte_shifted = *--cur_byte;
+        }
+    }
+
+    return( mbedtls_asn1_write_bitstring( p, start, buf, bits ) );
+}
+
 int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
                           const unsigned char *buf, size_t bits )
 {
     int ret;
-    size_t len = 0, size;
+    size_t len = 0;
+    size_t unused_bits, byte_len;
 
-    size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 );
+    byte_len = ( bits + 7 ) / 8;
+    unused_bits = ( byte_len * 8 ) - bits;
 
-    // Calculate byte length
-    //
-    if( *p < start || (size_t)( *p - start ) < size + 1 )
+    if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
-    len = size + 1;
-    (*p) -= size;
-    memcpy( *p, buf, size );
+    len = byte_len + 1;
 
-    // Write unused bits
-    //
-    *--(*p) = (unsigned char) (size * 8 - bits);
+    /* Write the bitstring. Ensure the unused bits are zeroed */
+    if( byte_len > 0 )
+    {
+        byte_len--;
+        *--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
+        ( *p ) -= byte_len;
+        memcpy( *p, buf, byte_len );
+    }
+
+    /* Write unused bits */
+    *--( *p ) = (unsigned char)unused_bits;
 
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) );
@@ -331,14 +380,36 @@ int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start,
     return( (int) len );
 }
 
-mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data **head,
+
+/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
+ * which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
+static mbedtls_asn1_named_data *asn1_find_named_data(
+                                               mbedtls_asn1_named_data *list,
+                                               const char *oid, size_t len )
+{
+    while( list != NULL )
+    {
+        if( list->oid.len == len &&
+            memcmp( list->oid.p, oid, len ) == 0 )
+        {
+            break;
+        }
+
+        list = list->next;
+    }
+
+    return( list );
+}
+
+mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
+                                        mbedtls_asn1_named_data **head,
                                         const char *oid, size_t oid_len,
                                         const unsigned char *val,
                                         size_t val_len )
 {
     mbedtls_asn1_named_data *cur;
 
-    if( ( cur = mbedtls_asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
+    if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
     {
         // Add new entry if not present yet based on OID
         //
diff --git a/features/mbedtls/src/bignum.c b/features/mbedtls/src/bignum.c
index ae5e7cfa0c..87015af0c8 100644
--- a/features/mbedtls/src/bignum.c
+++ b/features/mbedtls/src/bignum.c
@@ -59,6 +59,11 @@
 #define mbedtls_free       free
 #endif
 
+#define MPI_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_MPI_BAD_INPUT_DATA )
+#define MPI_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define ciL    (sizeof(mbedtls_mpi_uint))         /* chars in limb  */
 #define biL    (ciL << 3)               /* bits  in limb  */
 #define biH    (ciL << 2)               /* half limb size */
@@ -83,8 +88,7 @@ static void mbedtls_mpi_zeroize( mbedtls_mpi_uint *v, size_t n )
  */
 void mbedtls_mpi_init( mbedtls_mpi *X )
 {
-    if( X == NULL )
-        return;
+    MPI_VALIDATE( X != NULL );
 
     X->s = 1;
     X->n = 0;
@@ -116,6 +120,7 @@ void mbedtls_mpi_free( mbedtls_mpi *X )
 int mbedtls_mpi_grow( mbedtls_mpi *X, size_t nblimbs )
 {
     mbedtls_mpi_uint *p;
+    MPI_VALIDATE_RET( X != NULL );
 
     if( nblimbs > MBEDTLS_MPI_MAX_LIMBS )
         return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
@@ -147,6 +152,10 @@ int mbedtls_mpi_shrink( mbedtls_mpi *X, size_t nblimbs )
 {
     mbedtls_mpi_uint *p;
     size_t i;
+    MPI_VALIDATE_RET( X != NULL );
+
+    if( nblimbs > MBEDTLS_MPI_MAX_LIMBS )
+        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
 
     /* Actually resize up in this case */
     if( X->n <= nblimbs )
@@ -183,6 +192,8 @@ int mbedtls_mpi_copy( mbedtls_mpi *X, const mbedtls_mpi *Y )
 {
     int ret = 0;
     size_t i;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( Y != NULL );
 
     if( X == Y )
         return( 0 );
@@ -222,6 +233,8 @@ cleanup:
 void mbedtls_mpi_swap( mbedtls_mpi *X, mbedtls_mpi *Y )
 {
     mbedtls_mpi T;
+    MPI_VALIDATE( X != NULL );
+    MPI_VALIDATE( Y != NULL );
 
     memcpy( &T,  X, sizeof( mbedtls_mpi ) );
     memcpy(  X,  Y, sizeof( mbedtls_mpi ) );
@@ -237,6 +250,8 @@ int mbedtls_mpi_safe_cond_assign( mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned
 {
     int ret = 0;
     size_t i;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( Y != NULL );
 
     /* make sure assign is 0 or 1 in a time-constant manner */
     assign = (assign | (unsigned char)-assign) >> 7;
@@ -266,6 +281,8 @@ int mbedtls_mpi_safe_cond_swap( mbedtls_mpi *X, mbedtls_mpi *Y, unsigned char sw
     int ret, s;
     size_t i;
     mbedtls_mpi_uint tmp;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( Y != NULL );
 
     if( X == Y )
         return( 0 );
@@ -298,6 +315,7 @@ cleanup:
 int mbedtls_mpi_lset( mbedtls_mpi *X, mbedtls_mpi_sint z )
 {
     int ret;
+    MPI_VALIDATE_RET( X != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, 1 ) );
     memset( X->p, 0, X->n * ciL );
@@ -315,12 +333,18 @@ cleanup:
  */
 int mbedtls_mpi_get_bit( const mbedtls_mpi *X, size_t pos )
 {
+    MPI_VALIDATE_RET( X != NULL );
+
     if( X->n * biL <= pos )
         return( 0 );
 
     return( ( X->p[pos / biL] >> ( pos % biL ) ) & 0x01 );
 }
 
+/* Get a specific byte, without range checks. */
+#define GET_BYTE( X, i )                                \
+    ( ( ( X )->p[( i ) / ciL] >> ( ( ( i ) % ciL ) * 8 ) ) & 0xff )
+
 /*
  * Set a bit to a specific value of 0 or 1
  */
@@ -329,6 +353,7 @@ int mbedtls_mpi_set_bit( mbedtls_mpi *X, size_t pos, unsigned char val )
     int ret = 0;
     size_t off = pos / biL;
     size_t idx = pos % biL;
+    MPI_VALIDATE_RET( X != NULL );
 
     if( val != 0 && val != 1 )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
@@ -355,6 +380,7 @@ cleanup:
 size_t mbedtls_mpi_lsb( const mbedtls_mpi *X )
 {
     size_t i, j, count = 0;
+    MBEDTLS_INTERNAL_VALIDATE_RET( X != NULL, 0 );
 
     for( i = 0; i < X->n; i++ )
         for( j = 0; j < biL; j++, count++ )
@@ -435,6 +461,8 @@ int mbedtls_mpi_read_string( mbedtls_mpi *X, int radix, const char *s )
     size_t i, j, slen, n;
     mbedtls_mpi_uint d;
     mbedtls_mpi T;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( s != NULL );
 
     if( radix < 2 || radix > 16 )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
@@ -499,26 +527,38 @@ cleanup:
 }
 
 /*
- * Helper to write the digits high-order first
+ * Helper to write the digits high-order first.
  */
-static int mpi_write_hlp( mbedtls_mpi *X, int radix, char **p )
+static int mpi_write_hlp( mbedtls_mpi *X, int radix,
+                          char **p, const size_t buflen )
 {
     int ret;
     mbedtls_mpi_uint r;
+    size_t length = 0;
+    char *p_end = *p + buflen;
 
-    if( radix < 2 || radix > 16 )
-        return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+    do
+    {
+        if( length >= buflen )
+        {
+            return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
+        }
 
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mod_int( &r, X, radix ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_div_int( X, NULL, X, radix ) );
+        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_int( &r, X, radix ) );
+        MBEDTLS_MPI_CHK( mbedtls_mpi_div_int( X, NULL, X, radix ) );
+        /*
+         * Write the residue in the current position, as an ASCII character.
+         */
+        if( r < 0xA )
+            *(--p_end) = (char)( '0' + r );
+        else
+            *(--p_end) = (char)( 'A' + ( r - 0xA ) );
 
-    if( mbedtls_mpi_cmp_int( X, 0 ) != 0 )
-        MBEDTLS_MPI_CHK( mpi_write_hlp( X, radix, p ) );
+        length++;
+    } while( mbedtls_mpi_cmp_int( X, 0 ) != 0 );
 
-    if( r < 10 )
-        *(*p)++ = (char)( r + 0x30 );
-    else
-        *(*p)++ = (char)( r + 0x37 );
+    memmove( *p, p_end, length );
+    *p += length;
 
 cleanup:
 
@@ -535,6 +575,9 @@ int mbedtls_mpi_write_string( const mbedtls_mpi *X, int radix,
     size_t n;
     char *p;
     mbedtls_mpi T;
+    MPI_VALIDATE_RET( X    != NULL );
+    MPI_VALIDATE_RET( olen != NULL );
+    MPI_VALIDATE_RET( buflen == 0 || buf != NULL );
 
     if( radix < 2 || radix > 16 )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
@@ -588,7 +631,7 @@ int mbedtls_mpi_write_string( const mbedtls_mpi *X, int radix,
         if( T.s == -1 )
             T.s = 1;
 
-        MBEDTLS_MPI_CHK( mpi_write_hlp( &T, radix, &p ) );
+        MBEDTLS_MPI_CHK( mpi_write_hlp( &T, radix, &p, buflen ) );
     }
 
     *p++ = '\0';
@@ -616,6 +659,12 @@ int mbedtls_mpi_read_file( mbedtls_mpi *X, int radix, FILE *fin )
      */
     char s[ MBEDTLS_MPI_RW_BUFFER_SIZE ];
 
+    MPI_VALIDATE_RET( X   != NULL );
+    MPI_VALIDATE_RET( fin != NULL );
+
+    if( radix < 2 || radix > 16 )
+        return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+
     memset( s, 0, sizeof( s ) );
     if( fgets( s, sizeof( s ) - 1, fin ) == NULL )
         return( MBEDTLS_ERR_MPI_FILE_IO_ERROR );
@@ -647,6 +696,10 @@ int mbedtls_mpi_write_file( const char *p, const mbedtls_mpi *X, int radix, FILE
      * newline characters and '\0'
      */
     char s[ MBEDTLS_MPI_RW_BUFFER_SIZE ];
+    MPI_VALIDATE_RET( X != NULL );
+
+    if( radix < 2 || radix > 16 )
+        return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
 
     memset( s, 0, sizeof( s ) );
 
@@ -674,14 +727,104 @@ cleanup:
 }
 #endif /* MBEDTLS_FS_IO */
 
+
+/* Convert a big-endian byte array aligned to the size of mbedtls_mpi_uint
+ * into the storage form used by mbedtls_mpi. */
+
+static mbedtls_mpi_uint mpi_uint_bigendian_to_host_c( mbedtls_mpi_uint x )
+{
+    uint8_t i;
+    mbedtls_mpi_uint tmp = 0;
+    /* This works regardless of the endianness. */
+    for( i = 0; i < ciL; i++, x >>= 8 )
+        tmp |= ( x & 0xFF ) << ( ( ciL - 1 - i ) << 3 );
+    return( tmp );
+}
+
+static mbedtls_mpi_uint mpi_uint_bigendian_to_host( mbedtls_mpi_uint x )
+{
+#if defined(__BYTE_ORDER__)
+
+/* Nothing to do on bigendian systems. */
+#if ( __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ )
+    return( x );
+#endif /* __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ */
+
+#if ( __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ )
+
+/* For GCC and Clang, have builtins for byte swapping. */
+#if defined(__GNUC__) && defined(__GNUC_PREREQ)
+#if __GNUC_PREREQ(4,3)
+#define have_bswap
+#endif
+#endif
+
+#if defined(__clang__) && defined(__has_builtin)
+#if __has_builtin(__builtin_bswap32)  &&                 \
+    __has_builtin(__builtin_bswap64)
+#define have_bswap
+#endif
+#endif
+
+#if defined(have_bswap)
+    /* The compiler is hopefully able to statically evaluate this! */
+    switch( sizeof(mbedtls_mpi_uint) )
+    {
+        case 4:
+            return( __builtin_bswap32(x) );
+        case 8:
+            return( __builtin_bswap64(x) );
+    }
+#endif
+#endif /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */
+#endif /* __BYTE_ORDER__ */
+
+    /* Fall back to C-based reordering if we don't know the byte order
+     * or we couldn't use a compiler-specific builtin. */
+    return( mpi_uint_bigendian_to_host_c( x ) );
+}
+
+static void mpi_bigendian_to_host( mbedtls_mpi_uint * const p, size_t limbs )
+{
+    mbedtls_mpi_uint *cur_limb_left;
+    mbedtls_mpi_uint *cur_limb_right;
+    if( limbs == 0 )
+        return;
+
+    /*
+     * Traverse limbs and
+     * - adapt byte-order in each limb
+     * - swap the limbs themselves.
+     * For that, simultaneously traverse the limbs from left to right
+     * and from right to left, as long as the left index is not bigger
+     * than the right index (it's not a problem if limbs is odd and the
+     * indices coincide in the last iteration).
+     */
+    for( cur_limb_left = p, cur_limb_right = p + ( limbs - 1 );
+         cur_limb_left <= cur_limb_right;
+         cur_limb_left++, cur_limb_right-- )
+    {
+        mbedtls_mpi_uint tmp;
+        /* Note that if cur_limb_left == cur_limb_right,
+         * this code effectively swaps the bytes only once. */
+        tmp             = mpi_uint_bigendian_to_host( *cur_limb_left  );
+        *cur_limb_left  = mpi_uint_bigendian_to_host( *cur_limb_right );
+        *cur_limb_right = tmp;
+    }
+}
+
 /*
  * Import X from unsigned binary data, big endian
  */
 int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf, size_t buflen )
 {
     int ret;
-    size_t i, j;
-    size_t const limbs = CHARS_TO_LIMBS( buflen );
+    size_t const limbs    = CHARS_TO_LIMBS( buflen );
+    size_t const overhead = ( limbs * ciL ) - buflen;
+    unsigned char *Xp;
+
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( buflen == 0 || buf != NULL );
 
     /* Ensure that target MPI has exactly the necessary number of limbs */
     if( X->n != limbs )
@@ -690,11 +833,17 @@ int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf, size_t bu
         mbedtls_mpi_init( X );
         MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, limbs ) );
     }
-
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
 
-    for( i = buflen, j = 0; i > 0; i--, j++ )
-        X->p[j / ciL] |= ((mbedtls_mpi_uint) buf[i - 1]) << ((j % ciL) << 3);
+    /* Avoid calling `memcpy` with NULL source argument,
+     * even if buflen is 0. */
+    if( buf != NULL )
+    {
+        Xp = (unsigned char*) X->p;
+        memcpy( Xp + overhead, buf, buflen );
+
+        mpi_bigendian_to_host( X->p, limbs );
+    }
 
 cleanup:
 
@@ -704,19 +853,45 @@ cleanup:
 /*
  * Export X into unsigned binary data, big endian
  */
-int mbedtls_mpi_write_binary( const mbedtls_mpi *X, unsigned char *buf, size_t buflen )
+int mbedtls_mpi_write_binary( const mbedtls_mpi *X,
+                              unsigned char *buf, size_t buflen )
 {
-    size_t i, j, n;
+    size_t stored_bytes;
+    size_t bytes_to_copy;
+    unsigned char *p;
+    size_t i;
 
-    n = mbedtls_mpi_size( X );
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( buflen == 0 || buf != NULL );
 
-    if( buflen < n )
-        return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
+    stored_bytes = X->n * ciL;
 
-    memset( buf, 0, buflen );
+    if( stored_bytes < buflen )
+    {
+        /* There is enough space in the output buffer. Write initial
+         * null bytes and record the position at which to start
+         * writing the significant bytes. In this case, the execution
+         * trace of this function does not depend on the value of the
+         * number. */
+        bytes_to_copy = stored_bytes;
+        p = buf + buflen - stored_bytes;
+        memset( buf, 0, buflen - stored_bytes );
+    }
+    else
+    {
+        /* The output buffer is smaller than the allocated size of X.
+         * However X may fit if its leading bytes are zero. */
+        bytes_to_copy = buflen;
+        p = buf;
+        for( i = bytes_to_copy; i < stored_bytes; i++ )
+        {
+            if( GET_BYTE( X, i ) != 0 )
+                return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
+        }
+    }
 
-    for( i = buflen - 1, j = 0; n > 0; i--, j++, n-- )
-        buf[i] = (unsigned char)( X->p[j / ciL] >> ((j % ciL) << 3) );
+    for( i = 0; i < bytes_to_copy; i++ )
+        p[bytes_to_copy - i - 1] = GET_BYTE( X, i );
 
     return( 0 );
 }
@@ -729,6 +904,7 @@ int mbedtls_mpi_shift_l( mbedtls_mpi *X, size_t count )
     int ret;
     size_t i, v0, t1;
     mbedtls_mpi_uint r0 = 0, r1;
+    MPI_VALIDATE_RET( X != NULL );
 
     v0 = count / (biL    );
     t1 = count & (biL - 1);
@@ -778,6 +954,7 @@ int mbedtls_mpi_shift_r( mbedtls_mpi *X, size_t count )
 {
     size_t i, v0, v1;
     mbedtls_mpi_uint r0 = 0, r1;
+    MPI_VALIDATE_RET( X != NULL );
 
     v0 = count /  biL;
     v1 = count & (biL - 1);
@@ -820,6 +997,8 @@ int mbedtls_mpi_shift_r( mbedtls_mpi *X, size_t count )
 int mbedtls_mpi_cmp_abs( const mbedtls_mpi *X, const mbedtls_mpi *Y )
 {
     size_t i, j;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( Y != NULL );
 
     for( i = X->n; i > 0; i-- )
         if( X->p[i - 1] != 0 )
@@ -850,6 +1029,8 @@ int mbedtls_mpi_cmp_abs( const mbedtls_mpi *X, const mbedtls_mpi *Y )
 int mbedtls_mpi_cmp_mpi( const mbedtls_mpi *X, const mbedtls_mpi *Y )
 {
     size_t i, j;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( Y != NULL );
 
     for( i = X->n; i > 0; i-- )
         if( X->p[i - 1] != 0 )
@@ -884,6 +1065,7 @@ int mbedtls_mpi_cmp_int( const mbedtls_mpi *X, mbedtls_mpi_sint z )
 {
     mbedtls_mpi Y;
     mbedtls_mpi_uint p[1];
+    MPI_VALIDATE_RET( X != NULL );
 
     *p  = ( z < 0 ) ? -z : z;
     Y.s = ( z < 0 ) ? -1 : 1;
@@ -901,6 +1083,9 @@ int mbedtls_mpi_add_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
     int ret;
     size_t i, j;
     mbedtls_mpi_uint *o, *p, c, tmp;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
     if( X == B )
     {
@@ -978,6 +1163,9 @@ int mbedtls_mpi_sub_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
     mbedtls_mpi TB;
     int ret;
     size_t n;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
     if( mbedtls_mpi_cmp_abs( A, B ) < 0 )
         return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
@@ -1018,8 +1206,12 @@ cleanup:
  */
 int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
 {
-    int ret, s = A->s;
+    int ret, s;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
+    s = A->s;
     if( A->s * B->s < 0 )
     {
         if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
@@ -1049,8 +1241,12 @@ cleanup:
  */
 int mbedtls_mpi_sub_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
 {
-    int ret, s = A->s;
+    int ret, s;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
+    s = A->s;
     if( A->s * B->s > 0 )
     {
         if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
@@ -1082,6 +1278,8 @@ int mbedtls_mpi_add_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint
 {
     mbedtls_mpi _B;
     mbedtls_mpi_uint p[1];
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
 
     p[0] = ( b < 0 ) ? -b : b;
     _B.s = ( b < 0 ) ? -1 : 1;
@@ -1098,6 +1296,8 @@ int mbedtls_mpi_sub_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint
 {
     mbedtls_mpi _B;
     mbedtls_mpi_uint p[1];
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
 
     p[0] = ( b < 0 ) ? -b : b;
     _B.s = ( b < 0 ) ? -1 : 1;
@@ -1187,6 +1387,9 @@ int mbedtls_mpi_mul_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
     int ret;
     size_t i, j;
     mbedtls_mpi TA, TB;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
     mbedtls_mpi_init( &TA ); mbedtls_mpi_init( &TB );
 
@@ -1223,6 +1426,8 @@ int mbedtls_mpi_mul_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint
 {
     mbedtls_mpi _B;
     mbedtls_mpi_uint p[1];
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
 
     _B.s = 1;
     _B.n = 1;
@@ -1331,11 +1536,14 @@ static mbedtls_mpi_uint mbedtls_int_div_int( mbedtls_mpi_uint u1,
 /*
  * Division by mbedtls_mpi: A = Q * B + R  (HAC 14.20)
  */
-int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B )
+int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A,
+                         const mbedtls_mpi *B )
 {
     int ret;
     size_t i, n, t, k;
     mbedtls_mpi X, Y, Z, T1, T2;
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
     if( mbedtls_mpi_cmp_int( B, 0 ) == 0 )
         return( MBEDTLS_ERR_MPI_DIVISION_BY_ZERO );
@@ -1446,10 +1654,13 @@ cleanup:
 /*
  * Division by int: A = Q * b + R
  */
-int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, mbedtls_mpi_sint b )
+int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R,
+                         const mbedtls_mpi *A,
+                         mbedtls_mpi_sint b )
 {
     mbedtls_mpi _B;
     mbedtls_mpi_uint p[1];
+    MPI_VALIDATE_RET( A != NULL );
 
     p[0] = ( b < 0 ) ? -b : b;
     _B.s = ( b < 0 ) ? -1 : 1;
@@ -1465,6 +1676,9 @@ int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, m
 int mbedtls_mpi_mod_mpi( mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B )
 {
     int ret;
+    MPI_VALIDATE_RET( R != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
 
     if( mbedtls_mpi_cmp_int( B, 0 ) < 0 )
         return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
@@ -1489,6 +1703,8 @@ int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_
 {
     size_t i;
     mbedtls_mpi_uint x, y, z;
+    MPI_VALIDATE_RET( r != NULL );
+    MPI_VALIDATE_RET( A != NULL );
 
     if( b == 0 )
         return( MBEDTLS_ERR_MPI_DIVISION_BY_ZERO );
@@ -1602,7 +1818,8 @@ static int mpi_montmul( mbedtls_mpi *A, const mbedtls_mpi *B, const mbedtls_mpi
 /*
  * Montgomery reduction: A = A * R^-1 mod N
  */
-static int mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint mm, const mbedtls_mpi *T )
+static int mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N,
+                        mbedtls_mpi_uint mm, const mbedtls_mpi *T )
 {
     mbedtls_mpi_uint z = 1;
     mbedtls_mpi U;
@@ -1616,7 +1833,9 @@ static int mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint m
 /*
  * Sliding-window exponentiation: X = A^E mod N  (HAC 14.85)
  */
-int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *E, const mbedtls_mpi *N, mbedtls_mpi *_RR )
+int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A,
+                         const mbedtls_mpi *E, const mbedtls_mpi *N,
+                         mbedtls_mpi *_RR )
 {
     int ret;
     size_t wbits, wsize, one = 1;
@@ -1626,6 +1845,11 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
     mbedtls_mpi RR, T, W[ 2 << MBEDTLS_MPI_WINDOW_SIZE ], Apos;
     int neg;
 
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( E != NULL );
+    MPI_VALIDATE_RET( N != NULL );
+
     if( mbedtls_mpi_cmp_int( N, 0 ) <= 0 || ( N->p[0] & 1 ) == 0 )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
 
@@ -1830,6 +2054,10 @@ int mbedtls_mpi_gcd( mbedtls_mpi *G, const mbedtls_mpi *A, const mbedtls_mpi *B
     size_t lz, lzt;
     mbedtls_mpi TG, TA, TB;
 
+    MPI_VALIDATE_RET( G != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( B != NULL );
+
     mbedtls_mpi_init( &TG ); mbedtls_mpi_init( &TA ); mbedtls_mpi_init( &TB );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TA, A ) );
@@ -1885,16 +2113,28 @@ int mbedtls_mpi_fill_random( mbedtls_mpi *X, size_t size,
                      void *p_rng )
 {
     int ret;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+    size_t const limbs = CHARS_TO_LIMBS( size );
+    size_t const overhead = ( limbs * ciL ) - size;
+    unsigned char *Xp;
 
-    if( size > MBEDTLS_MPI_MAX_SIZE )
-        return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+    MPI_VALIDATE_RET( X     != NULL );
+    MPI_VALIDATE_RET( f_rng != NULL );
 
-    MBEDTLS_MPI_CHK( f_rng( p_rng, buf, size ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( X, buf, size ) );
+    /* Ensure that target MPI has exactly the necessary number of limbs */
+    if( X->n != limbs )
+    {
+        mbedtls_mpi_free( X );
+        mbedtls_mpi_init( X );
+        MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, limbs ) );
+    }
+    MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
+
+    Xp = (unsigned char*) X->p;
+    f_rng( p_rng, Xp + overhead, size );
+
+    mpi_bigendian_to_host( X->p, limbs );
 
 cleanup:
-    mbedtls_platform_zeroize( buf, sizeof( buf ) );
     return( ret );
 }
 
@@ -1905,6 +2145,9 @@ int mbedtls_mpi_inv_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
 {
     int ret;
     mbedtls_mpi G, TA, TU, U1, U2, TB, TV, V1, V2;
+    MPI_VALIDATE_RET( X != NULL );
+    MPI_VALIDATE_RET( A != NULL );
+    MPI_VALIDATE_RET( N != NULL );
 
     if( mbedtls_mpi_cmp_int( N, 1 ) <= 0 )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
@@ -2064,7 +2307,11 @@ static int mpi_miller_rabin( const mbedtls_mpi *X, size_t rounds,
     size_t i, j, k, s;
     mbedtls_mpi W, R, T, A, RR;
 
-    mbedtls_mpi_init( &W ); mbedtls_mpi_init( &R ); mbedtls_mpi_init( &T ); mbedtls_mpi_init( &A );
+    MPI_VALIDATE_RET( X     != NULL );
+    MPI_VALIDATE_RET( f_rng != NULL );
+
+    mbedtls_mpi_init( &W ); mbedtls_mpi_init( &R );
+    mbedtls_mpi_init( &T ); mbedtls_mpi_init( &A );
     mbedtls_mpi_init( &RR );
 
     /*
@@ -2136,7 +2383,8 @@ static int mpi_miller_rabin( const mbedtls_mpi *X, size_t rounds,
     }
 
 cleanup:
-    mbedtls_mpi_free( &W ); mbedtls_mpi_free( &R ); mbedtls_mpi_free( &T ); mbedtls_mpi_free( &A );
+    mbedtls_mpi_free( &W ); mbedtls_mpi_free( &R );
+    mbedtls_mpi_free( &T ); mbedtls_mpi_free( &A );
     mbedtls_mpi_free( &RR );
 
     return( ret );
@@ -2151,6 +2399,8 @@ int mbedtls_mpi_is_prime_ext( const mbedtls_mpi *X, int rounds,
 {
     int ret;
     mbedtls_mpi XX;
+    MPI_VALIDATE_RET( X     != NULL );
+    MPI_VALIDATE_RET( f_rng != NULL );
 
     XX.s = 1;
     XX.n = X->n;
@@ -2182,12 +2432,15 @@ int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
                   int (*f_rng)(void *, unsigned char *, size_t),
                   void *p_rng )
 {
+    MPI_VALIDATE_RET( X     != NULL );
+    MPI_VALIDATE_RET( f_rng != NULL );
+
     /*
      * In the past our key generation aimed for an error rate of at most
      * 2^-80. Since this function is deprecated, aim for the same certainty
      * here as well.
      */
-    return mbedtls_mpi_is_prime_ext( X, 40, f_rng, p_rng );
+    return( mbedtls_mpi_is_prime_ext( X, 40, f_rng, p_rng ) );
 }
 #endif
 
@@ -2215,6 +2468,9 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int flags,
     mbedtls_mpi_uint r;
     mbedtls_mpi Y;
 
+    MPI_VALIDATE_RET( X     != NULL );
+    MPI_VALIDATE_RET( f_rng != NULL );
+
     if( nbits < 3 || nbits > MBEDTLS_MPI_MAX_BITS )
         return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
 
diff --git a/features/mbedtls/src/blowfish.c b/features/mbedtls/src/blowfish.c
index 5b6bb9885f..cbf9238246 100644
--- a/features/mbedtls/src/blowfish.c
+++ b/features/mbedtls/src/blowfish.c
@@ -40,6 +40,12 @@
 
 #if !defined(MBEDTLS_BLOWFISH_ALT)
 
+/* Parameter validation macros */
+#define BLOWFISH_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA )
+#define BLOWFISH_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -153,6 +159,7 @@ static void blowfish_dec( mbedtls_blowfish_context *ctx, uint32_t *xl, uint32_t
 
 void mbedtls_blowfish_init( mbedtls_blowfish_context *ctx )
 {
+    BLOWFISH_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_blowfish_context ) );
 }
 
@@ -167,16 +174,20 @@ void mbedtls_blowfish_free( mbedtls_blowfish_context *ctx )
 /*
  * Blowfish key schedule
  */
-int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx, const unsigned char *key,
-                     unsigned int keybits )
+int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx,
+                             const unsigned char *key,
+                             unsigned int keybits )
 {
     unsigned int i, j, k;
     uint32_t data, datal, datar;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( key != NULL );
 
-    if( keybits < MBEDTLS_BLOWFISH_MIN_KEY_BITS || keybits > MBEDTLS_BLOWFISH_MAX_KEY_BITS ||
-        ( keybits % 8 ) )
+    if( keybits < MBEDTLS_BLOWFISH_MIN_KEY_BITS    ||
+        keybits > MBEDTLS_BLOWFISH_MAX_KEY_BITS    ||
+        keybits % 8 != 0 )
     {
-        return( MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH );
+        return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
     }
 
     keybits >>= 3;
@@ -231,6 +242,11 @@ int mbedtls_blowfish_crypt_ecb( mbedtls_blowfish_context *ctx,
                     unsigned char output[MBEDTLS_BLOWFISH_BLOCKSIZE] )
 {
     uint32_t X0, X1;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( input  != NULL );
+    BLOWFISH_VALIDATE_RET( output != NULL );
 
     GET_UINT32_BE( X0, input,  0 );
     GET_UINT32_BE( X1, input,  4 );
@@ -263,6 +279,12 @@ int mbedtls_blowfish_crypt_cbc( mbedtls_blowfish_context *ctx,
 {
     int i;
     unsigned char temp[MBEDTLS_BLOWFISH_BLOCKSIZE];
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( iv != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
 
     if( length % MBEDTLS_BLOWFISH_BLOCKSIZE )
         return( MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH );
@@ -317,7 +339,19 @@ int mbedtls_blowfish_crypt_cfb64( mbedtls_blowfish_context *ctx,
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( iv     != NULL );
+    BLOWFISH_VALIDATE_RET( iv_off != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *iv_off;
+    if( n >= 8 )
+        return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_BLOWFISH_DECRYPT )
     {
@@ -365,7 +399,17 @@ int mbedtls_blowfish_crypt_ctr( mbedtls_blowfish_context *ctx,
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( nonce_counter != NULL );
+    BLOWFISH_VALIDATE_RET( stream_block  != NULL );
+    BLOWFISH_VALIDATE_RET( nc_off != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *nc_off;
+    if( n >= 8 )
+        return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/features/mbedtls/src/camellia.c b/features/mbedtls/src/camellia.c
index 41b7da0fae..22262b89a8 100644
--- a/features/mbedtls/src/camellia.c
+++ b/features/mbedtls/src/camellia.c
@@ -49,6 +49,12 @@
 
 #if !defined(MBEDTLS_CAMELLIA_ALT)
 
+/* Parameter validation macros */
+#define CAMELLIA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA )
+#define CAMELLIA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -321,6 +327,7 @@ static void camellia_feistel( const uint32_t x[2], const uint32_t k[2],
 
 void mbedtls_camellia_init( mbedtls_camellia_context *ctx )
 {
+    CAMELLIA_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_camellia_context ) );
 }
 
@@ -335,8 +342,9 @@ void mbedtls_camellia_free( mbedtls_camellia_context *ctx )
 /*
  * Camellia key schedule (encryption)
  */
-int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits )
+int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits )
 {
     int idx;
     size_t i;
@@ -346,6 +354,9 @@ int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned c
     uint32_t KC[16];
     uint32_t TK[20];
 
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( key != NULL );
+
     RK = ctx->rk;
 
     memset( t, 0, 64 );
@@ -356,7 +367,7 @@ int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned c
         case 128: ctx->nr = 3; idx = 0; break;
         case 192:
         case 256: ctx->nr = 4; idx = 1; break;
-        default : return( MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH );
+        default : return( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA );
     }
 
     for( i = 0; i < keybits / 8; ++i )
@@ -440,14 +451,17 @@ int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned c
 /*
  * Camellia key schedule (decryption)
  */
-int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits )
+int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits )
 {
     int idx, ret;
     size_t i;
     mbedtls_camellia_context cty;
     uint32_t *RK;
     uint32_t *SK;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( key != NULL );
 
     mbedtls_camellia_init( &cty );
 
@@ -495,6 +509,11 @@ int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
 {
     int NR;
     uint32_t *RK, X[4];
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( input  != NULL );
+    CAMELLIA_VALIDATE_RET( output != NULL );
 
     ( (void) mode );
 
@@ -552,14 +571,20 @@ int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
  * Camellia-CBC buffer encryption/decryption
  */
 int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
-                    int mode,
-                    size_t length,
-                    unsigned char iv[16],
-                    const unsigned char *input,
-                    unsigned char *output )
+                                int mode,
+                                size_t length,
+                                unsigned char iv[16],
+                                const unsigned char *input,
+                                unsigned char *output )
 {
     int i;
     unsigned char temp[16];
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( iv != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
 
     if( length % 16 )
         return( MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH );
@@ -614,7 +639,18 @@ int mbedtls_camellia_crypt_cfb128( mbedtls_camellia_context *ctx,
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( iv     != NULL );
+    CAMELLIA_VALIDATE_RET( iv_off != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *iv_off;
+    if( n >= 16 )
+        return( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_CAMELLIA_DECRYPT )
     {
@@ -662,7 +698,17 @@ int mbedtls_camellia_crypt_ctr( mbedtls_camellia_context *ctx,
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( nonce_counter != NULL );
+    CAMELLIA_VALIDATE_RET( stream_block  != NULL );
+    CAMELLIA_VALIDATE_RET( nc_off != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *nc_off;
+    if( n >= 16 )
+        return( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/features/mbedtls/src/ccm.c b/features/mbedtls/src/ccm.c
index 90cab8e147..01e58b0436 100644
--- a/features/mbedtls/src/ccm.c
+++ b/features/mbedtls/src/ccm.c
@@ -52,6 +52,11 @@
 
 #if !defined(MBEDTLS_CCM_ALT)
 
+#define CCM_VALIDATE_RET( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CCM_BAD_INPUT )
+#define CCM_VALIDATE( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define CCM_ENCRYPT 0
 #define CCM_DECRYPT 1
 
@@ -60,6 +65,7 @@
  */
 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
 {
+    CCM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
 }
 
@@ -71,6 +77,9 @@ int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
     int ret;
     const mbedtls_cipher_info_t *cipher_info;
 
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( key != NULL );
+
     cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
     if( cipher_info == NULL )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
@@ -97,6 +106,8 @@ int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
  */
 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
 {
+    if( ctx == NULL )
+        return;
     mbedtls_cipher_free( &ctx->cipher_ctx );
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
 }
@@ -310,6 +321,12 @@ int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
                          const unsigned char *input, unsigned char *output,
                          unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
     return( ccm_auth_crypt( ctx, CCM_ENCRYPT, length, iv, iv_len,
                             add, add_len, input, output, tag, tag_len ) );
 }
@@ -320,6 +337,12 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
                          const unsigned char *input, unsigned char *output,
                          unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
     if( tag_len == 0 )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
 
@@ -341,6 +364,13 @@ int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
     unsigned char i;
     int diff;
 
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
     if( ( ret = ccm_auth_crypt( ctx, CCM_DECRYPT, length,
                                 iv, iv_len, add, add_len,
                                 input, output, check_tag, tag_len ) ) != 0 )
@@ -367,6 +397,13 @@ int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
                       const unsigned char *input, unsigned char *output,
                       const unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
     if( tag_len == 0 )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
 
diff --git a/features/mbedtls/src/chacha20.c b/features/mbedtls/src/chacha20.c
index d14a51e044..0757163e2f 100644
--- a/features/mbedtls/src/chacha20.c
+++ b/features/mbedtls/src/chacha20.c
@@ -53,6 +53,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define CHACHA20_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA )
+#define CHACHA20_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define BYTES_TO_U32_LE( data, offset )                           \
     ( (uint32_t) data[offset]                                     \
           | (uint32_t) ( (uint32_t) data[( offset ) + 1] << 8 )   \
@@ -181,14 +187,13 @@ static void chacha20_block( const uint32_t initial_state[16],
 
 void mbedtls_chacha20_init( mbedtls_chacha20_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx->state, sizeof( ctx->state ) );
-        mbedtls_platform_zeroize( ctx->keystream8, sizeof( ctx->keystream8 ) );
+    CHACHA20_VALIDATE( ctx != NULL );
 
-        /* Initially, there's no keystream bytes available */
-        ctx->keystream_bytes_used = CHACHA20_BLOCK_SIZE_BYTES;
-    }
+    mbedtls_platform_zeroize( ctx->state, sizeof( ctx->state ) );
+    mbedtls_platform_zeroize( ctx->keystream8, sizeof( ctx->keystream8 ) );
+
+    /* Initially, there's no keystream bytes available */
+    ctx->keystream_bytes_used = CHACHA20_BLOCK_SIZE_BYTES;
 }
 
 void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx )
@@ -202,10 +207,8 @@ void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx )
 int mbedtls_chacha20_setkey( mbedtls_chacha20_context *ctx,
                             const unsigned char key[32] )
 {
-    if( ( ctx == NULL ) || ( key == NULL ) )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( key != NULL );
 
     /* ChaCha20 constants - the string "expand 32-byte k" */
     ctx->state[0] = 0x61707865;
@@ -230,10 +233,8 @@ int mbedtls_chacha20_starts( mbedtls_chacha20_context* ctx,
                              const unsigned char nonce[12],
                              uint32_t counter )
 {
-    if( ( ctx == NULL ) || ( nonce == NULL ) )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( nonce != NULL );
 
     /* Counter */
     ctx->state[12] = counter;
@@ -259,15 +260,9 @@ int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx,
     size_t offset = 0U;
     size_t i;
 
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
-    else if( ( size > 0U ) && ( ( input == NULL ) || ( output == NULL ) ) )
-    {
-        /* input and output pointers are allowed to be NULL only if size == 0 */
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( size == 0 || input  != NULL );
+    CHACHA20_VALIDATE_RET( size == 0 || output != NULL );
 
     /* Use leftover keystream bytes, if available */
     while( size > 0U && ctx->keystream_bytes_used < CHACHA20_BLOCK_SIZE_BYTES )
@@ -332,6 +327,11 @@ int mbedtls_chacha20_crypt( const unsigned char key[32],
     mbedtls_chacha20_context ctx;
     int ret;
 
+    CHACHA20_VALIDATE_RET( key != NULL );
+    CHACHA20_VALIDATE_RET( nonce != NULL );
+    CHACHA20_VALIDATE_RET( data_len == 0 || input  != NULL );
+    CHACHA20_VALIDATE_RET( data_len == 0 || output != NULL );
+
     mbedtls_chacha20_init( &ctx );
 
     ret = mbedtls_chacha20_setkey( &ctx, key );
diff --git a/features/mbedtls/src/chachapoly.c b/features/mbedtls/src/chachapoly.c
index 860f877653..dc643dd618 100644
--- a/features/mbedtls/src/chachapoly.c
+++ b/features/mbedtls/src/chachapoly.c
@@ -44,6 +44,12 @@
 
 #if !defined(MBEDTLS_CHACHAPOLY_ALT)
 
+/* Parameter validation macros */
+#define CHACHAPOLY_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA )
+#define CHACHAPOLY_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define CHACHAPOLY_STATE_INIT       ( 0 )
 #define CHACHAPOLY_STATE_AAD        ( 1 )
 #define CHACHAPOLY_STATE_CIPHERTEXT ( 2 ) /* Encrypting or decrypting */
@@ -90,39 +96,35 @@ static int chachapoly_pad_ciphertext( mbedtls_chachapoly_context *ctx )
 
 void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_chacha20_init( &ctx->chacha20_ctx );
-        mbedtls_poly1305_init( &ctx->poly1305_ctx );
-        ctx->aad_len        = 0U;
-        ctx->ciphertext_len = 0U;
-        ctx->state          = CHACHAPOLY_STATE_INIT;
-        ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
-    }
+    CHACHAPOLY_VALIDATE( ctx != NULL );
+
+    mbedtls_chacha20_init( &ctx->chacha20_ctx );
+    mbedtls_poly1305_init( &ctx->poly1305_ctx );
+    ctx->aad_len        = 0U;
+    ctx->ciphertext_len = 0U;
+    ctx->state          = CHACHAPOLY_STATE_INIT;
+    ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
 }
 
 void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_chacha20_free( &ctx->chacha20_ctx );
-        mbedtls_poly1305_free( &ctx->poly1305_ctx );
-        ctx->aad_len        = 0U;
-        ctx->ciphertext_len = 0U;
-        ctx->state          = CHACHAPOLY_STATE_INIT;
-        ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
-    }
+    if( ctx == NULL )
+        return;
+
+    mbedtls_chacha20_free( &ctx->chacha20_ctx );
+    mbedtls_poly1305_free( &ctx->poly1305_ctx );
+    ctx->aad_len        = 0U;
+    ctx->ciphertext_len = 0U;
+    ctx->state          = CHACHAPOLY_STATE_INIT;
+    ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
 }
 
 int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
                                const unsigned char key[32] )
 {
     int ret;
-
-    if( ( ctx == NULL ) || ( key == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( key != NULL );
 
     ret = mbedtls_chacha20_setkey( &ctx->chacha20_ctx, key );
 
@@ -135,11 +137,8 @@ int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx,
 {
     int ret;
     unsigned char poly1305_key[64];
-
-    if( ( ctx == NULL ) || ( nonce == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
 
     /* Set counter = 0, will be update to 1 when generating Poly1305 key */
     ret = mbedtls_chacha20_starts( &ctx->chacha20_ctx, nonce, 0U );
@@ -176,19 +175,11 @@ int mbedtls_chachapoly_update_aad( mbedtls_chachapoly_context *ctx,
                                    const unsigned char *aad,
                                    size_t aad_len )
 {
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( aad_len > 0U ) && ( aad == NULL ) )
-    {
-        /* aad pointer is allowed to be NULL if aad_len == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ctx->state != CHACHAPOLY_STATE_AAD )
-    {
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad != NULL );
+
+    if( ctx->state != CHACHAPOLY_STATE_AAD )
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
-    }
 
     ctx->aad_len += aad_len;
 
@@ -201,18 +192,12 @@ int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx,
                                unsigned char *output )
 {
     int ret;
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( len == 0 || input != NULL );
+    CHACHAPOLY_VALIDATE_RET( len == 0 || output != NULL );
 
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( len > 0U ) && ( ( input == NULL ) || ( output == NULL ) ) )
-    {
-        /* input and output pointers are allowed to be NULL if len == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( ctx->state != CHACHAPOLY_STATE_AAD ) &&
-              ( ctx->state != CHACHAPOLY_STATE_CIPHERTEXT ) )
+    if( ( ctx->state != CHACHAPOLY_STATE_AAD ) &&
+        ( ctx->state != CHACHAPOLY_STATE_CIPHERTEXT ) )
     {
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
     }
@@ -257,12 +242,10 @@ int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
 {
     int ret;
     unsigned char len_block[16];
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( mac != NULL );
 
-    if( ( ctx == NULL ) || ( mac == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ctx->state == CHACHAPOLY_STATE_INIT )
+    if( ctx->state == CHACHAPOLY_STATE_INIT )
     {
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
     }
@@ -350,6 +333,13 @@ int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx,
                                         unsigned char *output,
                                         unsigned char tag[16] )
 {
+    CHACHAPOLY_VALIDATE_RET( ctx   != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
+    CHACHAPOLY_VALIDATE_RET( tag   != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad    != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || input  != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || output != NULL );
+
     return( chachapoly_crypt_and_tag( ctx, MBEDTLS_CHACHAPOLY_ENCRYPT,
                                       length, nonce, aad, aad_len,
                                       input, output, tag ) );
@@ -368,9 +358,12 @@ int mbedtls_chachapoly_auth_decrypt( mbedtls_chachapoly_context *ctx,
     unsigned char check_tag[16];
     size_t i;
     int diff;
-
-    if( tag == NULL )
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    CHACHAPOLY_VALIDATE_RET( ctx   != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
+    CHACHAPOLY_VALIDATE_RET( tag   != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad    != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || input  != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || output != NULL );
 
     if( ( ret = chachapoly_crypt_and_tag( ctx,
                         MBEDTLS_CHACHAPOLY_DECRYPT, length, nonce,
diff --git a/features/mbedtls/src/cipher.c b/features/mbedtls/src/cipher.c
index 1cc0beb288..9ceea13d61 100644
--- a/features/mbedtls/src/cipher.c
+++ b/features/mbedtls/src/cipher.c
@@ -70,6 +70,11 @@
 #define mbedtls_free   free
 #endif
 
+#define CIPHER_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA )
+#define CIPHER_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
 /* Compare the contents of two buffers in constant time.
  * Returns 0 if the contents are bitwise identical, otherwise returns
@@ -87,7 +92,7 @@ static int mbedtls_constant_time_memcmp( const void *v1, const void *v2,
     for( diff = 0, i = 0; i < len; i++ )
         diff |= p1[i] ^ p2[i];
 
-    return (int)diff;
+    return( (int)diff );
 }
 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
 
@@ -159,6 +164,7 @@ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(
 
 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx )
 {
+    CIPHER_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
 }
 
@@ -208,7 +214,8 @@ void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx )
 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
                           const mbedtls_cipher_info_t *cipher_info )
 {
-    if( NULL == cipher_info || NULL == ctx )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    if( cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
@@ -269,17 +276,12 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
                            int key_bitlen,
                            const mbedtls_operation_t operation )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info ||
-        NULL == ctx->cipher_ctx )
-    {
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( key != NULL );
+    CIPHER_VALIDATE_RET( operation == MBEDTLS_ENCRYPT ||
+                         operation == MBEDTLS_DECRYPT );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
-    }
-
-    if( operation != MBEDTLS_DECRYPT &&
-        operation != MBEDTLS_ENCRYPT )
-    {
-        return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
-    }
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
@@ -302,12 +304,18 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
         if( cipher_psa->slot_state != MBEDTLS_CIPHER_PSA_KEY_UNSET )
             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
-        /* Find a fresh key slot to use. */
-        status = mbedtls_psa_get_free_key_slot( &cipher_psa->slot );
+        key_type = mbedtls_psa_translate_cipher_type(
+            ctx->cipher_info->type );
+        if( key_type == 0 )
+            return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
+
+        /* Allocate a key slot to use. */
+        status = psa_allocate_key( &cipher_psa->slot );
         if( status != PSA_SUCCESS )
             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
-         /* Indicate that we own the key slot and need to
-          * destroy it in mbedtls_cipher_free(). */
+
+        /* Indicate that we own the key slot and need to
+         * destroy it in mbedtls_cipher_free(). */
         cipher_psa->slot_state = MBEDTLS_CIPHER_PSA_KEY_OWNED;
 
         /* From that point on, the responsibility for destroying the
@@ -316,7 +324,7 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
          * mbedtls_cipher_free() needs to be called in any case. */
 
         /* Setup policy for the new key slot. */
-        psa_key_policy_init( &key_policy );
+        key_policy = psa_key_policy_init();
 
         /* Mbed TLS' cipher layer doesn't enforce the mode of operation
          * (encrypt vs. decrypt): it is possible to setup a key for encryption
@@ -330,10 +338,6 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
 
         /* Populate new key slot. */
-        key_type = mbedtls_psa_translate_cipher_type(
-            ctx->cipher_info->type );
-        if( key_type == 0 )
-            return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
         status = psa_import_key( cipher_psa->slot,
                                  key_type, key, key_bytelen );
         if( status != PSA_SUCCESS )
@@ -362,27 +366,27 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
         MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
         MBEDTLS_MODE_CTR == ctx->cipher_info->mode )
     {
-        return ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
-                                                        ctx->key_bitlen );
+        return( ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
+                                                         ctx->key_bitlen ) );
     }
 
     if( MBEDTLS_DECRYPT == operation )
-        return ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key,
-                                                        ctx->key_bitlen );
-
+        return( ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key,
+                                                         ctx->key_bitlen ) );
 
     return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 }
 
 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
-                   const unsigned char *iv, size_t iv_len )
+                           const unsigned char *iv,
+                           size_t iv_len )
 {
     size_t actual_iv_size;
-    if( NULL == ctx || NULL == ctx->cipher_info )
-        return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
-    else if( NULL == iv && iv_len != 0  )
-        return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
+    if( ctx->cipher_info == NULL )
+        return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
     {
@@ -393,9 +397,6 @@ int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
     }
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
-    if( NULL == iv && iv_len == 0 )
-        ctx->iv_size = 0;
-
     /* avoid buffer overflow in ctx->iv */
     if( iv_len > MBEDTLS_MAX_IV_LENGTH )
         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
@@ -434,7 +435,8 @@ int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
 
 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -455,7 +457,9 @@ int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
                       const unsigned char *ad, size_t ad_len )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -471,8 +475,8 @@ int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
 #if defined(MBEDTLS_GCM_C)
     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
     {
-        return mbedtls_gcm_starts( (mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
-                           ctx->iv, ctx->iv_size, ad, ad_len );
+        return( mbedtls_gcm_starts( (mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
+                                    ctx->iv, ctx->iv_size, ad, ad_len ) );
     }
 #endif
 
@@ -492,8 +496,8 @@ int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
         if ( result != 0 )
             return( result );
 
-        return mbedtls_chachapoly_update_aad( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
-                                                          ad, ad_len );
+        return( mbedtls_chachapoly_update_aad( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
+                                               ad, ad_len ) );
     }
 #endif
 
@@ -505,12 +509,14 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
                    size_t ilen, unsigned char *output, size_t *olen )
 {
     int ret;
-    size_t block_size = 0;
+    size_t block_size;
 
-    if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen )
-    {
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
+    CIPHER_VALIDATE_RET( output != NULL );
+    CIPHER_VALIDATE_RET( olen != NULL );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
-    }
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
@@ -545,8 +551,8 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
     if( ctx->cipher_info->mode == MBEDTLS_MODE_GCM )
     {
         *olen = ilen;
-        return mbedtls_gcm_update( (mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
-                           output );
+        return( mbedtls_gcm_update( (mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
+                                    output ) );
     }
 #endif
 
@@ -554,14 +560,14 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
     if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
     {
         *olen = ilen;
-        return mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
-                                                      ilen, input, output );
+        return( mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
+                                           ilen, input, output ) );
     }
 #endif
 
     if ( 0 == block_size )
     {
-        return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
+        return( MBEDTLS_ERR_CIPHER_INVALID_CONTEXT );
     }
 
     if( input == output &&
@@ -624,7 +630,7 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
         {
             if( 0 == block_size )
             {
-                return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
+                return( MBEDTLS_ERR_CIPHER_INVALID_CONTEXT );
             }
 
             /* Encryption: only cache partial blocks
@@ -925,7 +931,10 @@ static int get_no_padding( unsigned char *input, size_t input_len,
 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
                    unsigned char *output, size_t *olen )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( output != NULL );
+    CIPHER_VALIDATE_RET( olen != NULL );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -1005,8 +1014,8 @@ int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
 
         /* Set output size for decryption */
         if( MBEDTLS_DECRYPT == ctx->operation )
-            return ctx->get_padding( output, mbedtls_cipher_get_block_size( ctx ),
-                                     olen );
+            return( ctx->get_padding( output, mbedtls_cipher_get_block_size( ctx ),
+                                      olen ) );
 
         /* Set output size for encryption */
         *olen = mbedtls_cipher_get_block_size( ctx );
@@ -1023,8 +1032,9 @@ int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
                                      mbedtls_cipher_padding_t mode )
 {
-    if( NULL == ctx ||
-        MBEDTLS_MODE_CBC != ctx->cipher_info->mode )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+
+    if( NULL == ctx->cipher_info || MBEDTLS_MODE_CBC != ctx->cipher_info->mode )
     {
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     }
@@ -1085,7 +1095,9 @@ int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
                       unsigned char *tag, size_t tag_len )
 {
-    if( NULL == ctx || NULL == ctx->cipher_info || NULL == tag )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
     if( MBEDTLS_ENCRYPT != ctx->operation )
@@ -1130,8 +1142,12 @@ int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
     unsigned char check_tag[16];
     int ret;
 
-    if( NULL == ctx || NULL == ctx->cipher_info ||
-        MBEDTLS_DECRYPT != ctx->operation )
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
+        return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
+
+    if( MBEDTLS_DECRYPT != ctx->operation )
     {
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     }
@@ -1204,6 +1220,12 @@ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
     int ret;
     size_t finish_olen;
 
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
+    CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
+    CIPHER_VALIDATE_RET( output != NULL );
+    CIPHER_VALIDATE_RET( olen != NULL );
+
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
     {
@@ -1216,7 +1238,7 @@ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
 
         psa_status_t status;
-        psa_cipher_operation_t cipher_op;
+        psa_cipher_operation_t cipher_op = PSA_CIPHER_OPERATION_INIT;
         size_t part_len;
 
         if( ctx->operation == MBEDTLS_DECRYPT )
@@ -1292,6 +1314,14 @@ int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
                          unsigned char *output, size_t *olen,
                          unsigned char *tag, size_t tag_len )
 {
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( iv != NULL );
+    CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
+    CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
+    CIPHER_VALIDATE_RET( output != NULL );
+    CIPHER_VALIDATE_RET( olen != NULL );
+    CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
     {
@@ -1371,6 +1401,14 @@ int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
                          unsigned char *output, size_t *olen,
                          const unsigned char *tag, size_t tag_len )
 {
+    CIPHER_VALIDATE_RET( ctx != NULL );
+    CIPHER_VALIDATE_RET( iv != NULL );
+    CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
+    CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
+    CIPHER_VALIDATE_RET( output != NULL );
+    CIPHER_VALIDATE_RET( olen != NULL );
+    CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if( ctx->psa_enabled == 1 )
     {
diff --git a/features/mbedtls/src/ctr_drbg.c b/features/mbedtls/src/ctr_drbg.c
index fead18f723..0db7beb29d 100644
--- a/features/mbedtls/src/ctr_drbg.c
+++ b/features/mbedtls/src/ctr_drbg.c
@@ -102,7 +102,8 @@ int mbedtls_ctr_drbg_seed_entropy_len(
     /*
      * Initialize with an empty key
      */
-    if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
+    if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, key,
+                                        MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
     {
         return( ret );
     }
@@ -120,8 +121,9 @@ int mbedtls_ctr_drbg_seed( mbedtls_ctr_drbg_context *ctx,
                    const unsigned char *custom,
                    size_t len )
 {
-    return( mbedtls_ctr_drbg_seed_entropy_len( ctx, f_entropy, p_entropy, custom, len,
-                                       MBEDTLS_CTR_DRBG_ENTROPY_LEN ) );
+    return( mbedtls_ctr_drbg_seed_entropy_len( ctx, f_entropy, p_entropy,
+                                               custom, len,
+                                               MBEDTLS_CTR_DRBG_ENTROPY_LEN ) );
 }
 
 void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
@@ -136,17 +138,20 @@ void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ctr_drbg_context ) );
 }
 
-void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx, int resistance )
+void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx,
+                                                 int resistance )
 {
     ctx->prediction_resistance = resistance;
 }
 
-void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx, size_t len )
+void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx,
+                                       size_t len )
 {
     ctx->entropy_len = len;
 }
 
-void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, int interval )
+void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx,
+                                           int interval )
 {
     ctx->reseed_interval = interval;
 }
@@ -154,7 +159,8 @@ void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, int in
 static int block_cipher_df( unsigned char *output,
                             const unsigned char *data, size_t data_len )
 {
-    unsigned char buf[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16];
+    unsigned char buf[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT +
+                      MBEDTLS_CTR_DRBG_BLOCKSIZE + 16];
     unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
     unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
     unsigned char chain[MBEDTLS_CTR_DRBG_BLOCKSIZE];
@@ -168,7 +174,8 @@ static int block_cipher_df( unsigned char *output,
     if( data_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
         return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
 
-    memset( buf, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16 );
+    memset( buf, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT +
+            MBEDTLS_CTR_DRBG_BLOCKSIZE + 16 );
     mbedtls_aes_init( &aes_ctx );
 
     /*
@@ -193,7 +200,8 @@ static int block_cipher_df( unsigned char *output,
     for( i = 0; i < MBEDTLS_CTR_DRBG_KEYSIZE; i++ )
         key[i] = i;
 
-    if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
+    if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, key,
+                                        MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
     {
         goto exit;
     }
@@ -215,7 +223,8 @@ static int block_cipher_df( unsigned char *output,
             use_len -= ( use_len >= MBEDTLS_CTR_DRBG_BLOCKSIZE ) ?
                        MBEDTLS_CTR_DRBG_BLOCKSIZE : use_len;
 
-            if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, chain, chain ) ) != 0 )
+            if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                               chain, chain ) ) != 0 )
             {
                 goto exit;
             }
@@ -232,7 +241,8 @@ static int block_cipher_df( unsigned char *output,
     /*
      * Do final encryption with reduced data
      */
-    if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
+    if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, tmp,
+                                        MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
     {
         goto exit;
     }
@@ -241,7 +251,8 @@ static int block_cipher_df( unsigned char *output,
 
     for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
     {
-        if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, iv, iv ) ) != 0 )
+        if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                           iv, iv ) ) != 0 )
         {
             goto exit;
         }
@@ -277,7 +288,7 @@ exit:
  *   ctx->counter = V
  */
 static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
-                              const unsigned char data[MBEDTLS_CTR_DRBG_SEEDLEN] )
+                          const unsigned char data[MBEDTLS_CTR_DRBG_SEEDLEN] )
 {
     unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
     unsigned char *p = tmp;
@@ -298,9 +309,10 @@ static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
         /*
          * Crypt counter block
          */
-        if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, p ) ) != 0 )
+        if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                           ctx->counter, p ) ) != 0 )
         {
-            return( ret );
+            goto exit;
         }
 
         p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
@@ -312,13 +324,17 @@ static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
     /*
      * Update key and counter
      */
-    if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
+    if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, tmp,
+                                        MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
     {
-        return( ret );
+        goto exit;
     }
-    memcpy( ctx->counter, tmp + MBEDTLS_CTR_DRBG_KEYSIZE, MBEDTLS_CTR_DRBG_BLOCKSIZE );
+    memcpy( ctx->counter, tmp + MBEDTLS_CTR_DRBG_KEYSIZE,
+            MBEDTLS_CTR_DRBG_BLOCKSIZE );
 
-    return( 0 );
+exit:
+    mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
+    return( ret );
 }
 
 /* CTR_DRBG_Instantiate with derivation function (SP 800-90A &sect;10.2.1.3.2)
@@ -333,23 +349,39 @@ static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
  * and with outputs
  *   ctx = initial_working_state
  */
-void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
-                      const unsigned char *additional, size_t add_len )
+int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
+                                 const unsigned char *additional,
+                                 size_t add_len )
 {
     unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
+    int ret;
 
-    if( add_len > 0 )
-    {
-        /* MAX_INPUT would be more logical here, but we have to match
-         * block_cipher_df()'s limits since we can't propagate errors */
-        if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
-            add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
+    if( add_len == 0 )
+        return( 0 );
 
-        block_cipher_df( add_input, additional, add_len );
-        ctr_drbg_update_internal( ctx, add_input );
-    }
+    if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
+        goto exit;
+    if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
+        goto exit;
+
+exit:
+    mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
+    return( ret );
 }
 
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
+                              const unsigned char *additional,
+                              size_t add_len )
+{
+    /* MAX_INPUT would be more logical here, but we have to match
+     * block_cipher_df()'s limits since we can't propagate errors */
+    if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
+        add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
+    (void) mbedtls_ctr_drbg_update_ret( ctx, additional, add_len );
+}
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
 /* CTR_DRBG_Reseed with derivation function (SP 800-90A &sect;10.2.1.4.2)
  * mbedtls_ctr_drbg_reseed(ctx, additional, len)
  * implements
@@ -399,20 +431,18 @@ int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
      * Reduce to 384 bits
      */
     if( ( ret = block_cipher_df( seed, seed, seedlen ) ) != 0 )
-    {
-        return( ret );
-    }
+        goto exit;
 
     /*
      * Update state
      */
     if( ( ret = ctr_drbg_update_internal( ctx, seed ) ) != 0 )
-    {
-        return( ret );
-    }
+        goto exit;
     ctx->reseed_counter = 1;
 
-    return( 0 );
+exit:
+    mbedtls_platform_zeroize( seed, sizeof( seed ) );
+    return( ret );
 }
 
 /* CTR_DRBG_Generate with derivation function (SP 800-90A &sect;10.2.1.5.2)
@@ -467,13 +497,9 @@ int mbedtls_ctr_drbg_random_with_add( void *p_rng,
     if( add_len > 0 )
     {
         if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
-        {
-            return( ret );
-        }
+            goto exit;
         if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
-        {
-            return( ret );
-        }
+            goto exit;
     }
 
     while( output_len > 0 )
@@ -488,13 +514,14 @@ int mbedtls_ctr_drbg_random_with_add( void *p_rng,
         /*
          * Crypt counter block
          */
-        if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, tmp ) ) != 0 )
+        if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                           ctx->counter, tmp ) ) != 0 )
         {
-            return( ret );
+            goto exit;
         }
 
-        use_len = ( output_len > MBEDTLS_CTR_DRBG_BLOCKSIZE ) ? MBEDTLS_CTR_DRBG_BLOCKSIZE :
-                                                       output_len;
+        use_len = ( output_len > MBEDTLS_CTR_DRBG_BLOCKSIZE )
+            ? MBEDTLS_CTR_DRBG_BLOCKSIZE : output_len;
         /*
          * Copy random block to destination
          */
@@ -504,16 +531,18 @@ int mbedtls_ctr_drbg_random_with_add( void *p_rng,
     }
 
     if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
-    {
-        return( ret );
-    }
+        goto exit;
 
     ctx->reseed_counter++;
 
+exit:
+    mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
+    mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
     return( 0 );
 }
 
-int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output, size_t output_len )
+int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output,
+                             size_t output_len )
 {
     int ret;
     mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
@@ -534,7 +563,8 @@ int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output, size_t output_l
 }
 
 #if defined(MBEDTLS_FS_IO)
-int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
+int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx,
+                                      const char *path )
 {
     int ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
     FILE *f;
@@ -543,13 +573,19 @@ int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char
     if( ( f = fopen( path, "wb" ) ) == NULL )
         return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
 
-    if( ( ret = mbedtls_ctr_drbg_random( ctx, buf, MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
+    if( ( ret = mbedtls_ctr_drbg_random( ctx, buf,
+                                         MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
         goto exit;
 
-    if( fwrite( buf, 1, MBEDTLS_CTR_DRBG_MAX_INPUT, f ) != MBEDTLS_CTR_DRBG_MAX_INPUT )
+    if( fwrite( buf, 1, MBEDTLS_CTR_DRBG_MAX_INPUT, f ) !=
+        MBEDTLS_CTR_DRBG_MAX_INPUT )
+    {
         ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
+    }
     else
+    {
         ret = 0;
+    }
 
 exit:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
@@ -558,38 +594,40 @@ exit:
     return( ret );
 }
 
-int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
+int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx,
+                                       const char *path )
 {
     int ret = 0;
-    FILE *f;
+    FILE *f = NULL;
     size_t n;
     unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
+    unsigned char c;
 
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
 
-    fseek( f, 0, SEEK_END );
-    n = (size_t) ftell( f );
-    fseek( f, 0, SEEK_SET );
-
-    if( n > MBEDTLS_CTR_DRBG_MAX_INPUT )
+    n = fread( buf, 1, sizeof( buf ), f );
+    if( fread( &c, 1, 1, f ) != 0 )
     {
-        fclose( f );
-        return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
+        ret = MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG;
+        goto exit;
     }
-
-    if( fread( buf, 1, n, f ) != n )
+    if( n == 0 || ferror( f ) )
+    {
         ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
-    else
-        mbedtls_ctr_drbg_update( ctx, buf, n );
-
+        goto exit;
+    }
     fclose( f );
+    f = NULL;
 
+    ret = mbedtls_ctr_drbg_update_ret( ctx, buf, n );
+
+exit:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
-
+    if( f != NULL )
+        fclose( f );
     if( ret != 0 )
         return( ret );
-
     return( mbedtls_ctr_drbg_write_seed_file( ctx, path ) );
 }
 #endif /* MBEDTLS_FS_IO */
@@ -671,7 +709,7 @@ int mbedtls_ctr_drbg_self_test( int verbose )
 
     test_offset = 0;
     CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
-                                (void *) entropy_source_pr, nonce_pers_pr, 16, 32 ) );
+                         (void *) entropy_source_pr, nonce_pers_pr, 16, 32 ) );
     mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
     CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
     CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
@@ -692,7 +730,7 @@ int mbedtls_ctr_drbg_self_test( int verbose )
 
     test_offset = 0;
     CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
-                            (void *) entropy_source_nopr, nonce_pers_nopr, 16, 32 ) );
+                     (void *) entropy_source_nopr, nonce_pers_nopr, 16, 32 ) );
     CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
     CHK( mbedtls_ctr_drbg_reseed( &ctx, NULL, 0 ) );
     CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
diff --git a/features/mbedtls/src/debug.c b/features/mbedtls/src/debug.c
index db3924ac54..6e1efbf94b 100644
--- a/features/mbedtls/src/debug.c
+++ b/features/mbedtls/src/debug.c
@@ -35,6 +35,7 @@
 #define mbedtls_free        free
 #define mbedtls_time_t      time_t
 #define mbedtls_snprintf    snprintf
+#define mbedtls_vsnprintf   vsnprintf
 #endif
 
 #include "mbedtls/debug.h"
@@ -90,20 +91,7 @@ void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
         return;
 
     va_start( argp, format );
-#if defined(_WIN32)
-#if defined(_TRUNCATE) && !defined(__MINGW32__)
-    ret = _vsnprintf_s( str, DEBUG_BUF_SIZE, _TRUNCATE, format, argp );
-#else
-    ret = _vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
-    if( ret < 0 || (size_t) ret == DEBUG_BUF_SIZE )
-    {
-        str[DEBUG_BUF_SIZE-1] = '\0';
-        ret = -1;
-    }
-#endif
-#else
-    ret = vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
-#endif
+    ret = mbedtls_vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
     va_end( argp );
 
     if( ret >= 0 && ret < DEBUG_BUF_SIZE - 1 )
@@ -365,4 +353,54 @@ void mbedtls_debug_print_crt( const mbedtls_ssl_context *ssl, int level,
 }
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
+#if defined(MBEDTLS_ECDH_C)
+static void mbedtls_debug_printf_ecdh_internal( const mbedtls_ssl_context *ssl,
+                                                int level, const char *file,
+                                                int line,
+                                                const mbedtls_ecdh_context *ecdh,
+                                                mbedtls_debug_ecdh_attr attr )
+{
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    const mbedtls_ecdh_context* ctx = ecdh;
+#else
+    const mbedtls_ecdh_context_mbed* ctx = &ecdh->ctx.mbed_ecdh;
+#endif
+
+    switch( attr )
+    {
+        case MBEDTLS_DEBUG_ECDH_Q:
+            mbedtls_debug_print_ecp( ssl, level, file, line, "ECDH: Q",
+                                     &ctx->Q );
+            break;
+        case MBEDTLS_DEBUG_ECDH_QP:
+            mbedtls_debug_print_ecp( ssl, level, file, line, "ECDH: Qp",
+                                     &ctx->Qp );
+            break;
+        case MBEDTLS_DEBUG_ECDH_Z:
+            mbedtls_debug_print_mpi( ssl, level, file, line, "ECDH: z",
+                                     &ctx->z );
+            break;
+        default:
+            break;
+    }
+}
+
+void mbedtls_debug_printf_ecdh( const mbedtls_ssl_context *ssl, int level,
+                                const char *file, int line,
+                                const mbedtls_ecdh_context *ecdh,
+                                mbedtls_debug_ecdh_attr attr )
+{
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    mbedtls_debug_printf_ecdh_internal( ssl, level, file, line, ecdh, attr );
+#else
+    switch( ecdh->var )
+    {
+        default:
+            mbedtls_debug_printf_ecdh_internal( ssl, level, file, line, ecdh,
+                                                attr );
+    }
+#endif
+}
+#endif /* MBEDTLS_ECDH_C */
+
 #endif /* MBEDTLS_DEBUG_C */
diff --git a/features/mbedtls/src/dhm.c b/features/mbedtls/src/dhm.c
index 82cbb0ce88..fb6937e854 100644
--- a/features/mbedtls/src/dhm.c
+++ b/features/mbedtls/src/dhm.c
@@ -60,6 +60,11 @@
 
 #if !defined(MBEDTLS_DHM_ALT)
 
+#define DHM_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_DHM_BAD_INPUT_DATA )
+#define DHM_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * helper to validate the mbedtls_mpi size and import it
  */
@@ -121,6 +126,7 @@ cleanup:
 
 void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
 {
+    DHM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
 }
 
@@ -132,6 +138,9 @@ int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
                      const unsigned char *end )
 {
     int ret;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( p != NULL && *p != NULL );
+    DHM_VALIDATE_RET( end != NULL );
 
     if( ( ret = dhm_read_bignum( &ctx->P,  p, end ) ) != 0 ||
         ( ret = dhm_read_bignum( &ctx->G,  p, end ) ) != 0 ||
@@ -157,6 +166,10 @@ int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
     int ret, count = 0;
     size_t n1, n2, n3;
     unsigned char *p;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( olen != NULL );
+    DHM_VALIDATE_RET( f_rng != NULL );
 
     if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
@@ -227,9 +240,9 @@ int mbedtls_dhm_set_group( mbedtls_dhm_context *ctx,
                            const mbedtls_mpi *G )
 {
     int ret;
-
-    if( ctx == NULL || P == NULL || G == NULL )
-        return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( P != NULL );
+    DHM_VALIDATE_RET( G != NULL );
 
     if( ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ||
         ( ret = mbedtls_mpi_copy( &ctx->G, G ) ) != 0 )
@@ -248,8 +261,10 @@ int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
                      const unsigned char *input, size_t ilen )
 {
     int ret;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( input != NULL );
 
-    if( ctx == NULL || ilen < 1 || ilen > ctx->len )
+    if( ilen < 1 || ilen > ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
@@ -267,8 +282,11 @@ int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
                      void *p_rng )
 {
     int ret, count = 0;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( f_rng != NULL );
 
-    if( ctx == NULL || olen < 1 || olen > ctx->len )
+    if( olen < 1 || olen > ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
@@ -380,8 +398,11 @@ int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
 {
     int ret;
     mbedtls_mpi GYb;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( olen != NULL );
 
-    if( ctx == NULL || output_size < ctx->len )
+    if( output_size < ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
@@ -428,11 +449,19 @@ cleanup:
  */
 void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
 {
-    mbedtls_mpi_free( &ctx->pX ); mbedtls_mpi_free( &ctx->Vf );
-    mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->RP );
-    mbedtls_mpi_free( &ctx->K  ); mbedtls_mpi_free( &ctx->GY );
-    mbedtls_mpi_free( &ctx->GX ); mbedtls_mpi_free( &ctx->X  );
-    mbedtls_mpi_free( &ctx->G  ); mbedtls_mpi_free( &ctx->P  );
+    if( ctx == NULL )
+        return;
+
+    mbedtls_mpi_free( &ctx->pX );
+    mbedtls_mpi_free( &ctx->Vf );
+    mbedtls_mpi_free( &ctx->Vi );
+    mbedtls_mpi_free( &ctx->RP );
+    mbedtls_mpi_free( &ctx->K  );
+    mbedtls_mpi_free( &ctx->GY );
+    mbedtls_mpi_free( &ctx->GX );
+    mbedtls_mpi_free( &ctx->X  );
+    mbedtls_mpi_free( &ctx->G  );
+    mbedtls_mpi_free( &ctx->P  );
 
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_dhm_context ) );
 }
@@ -449,7 +478,12 @@ int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
     unsigned char *p, *end;
 #if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_context pem;
+#endif /* MBEDTLS_PEM_PARSE_C */
 
+    DHM_VALIDATE_RET( dhm != NULL );
+    DHM_VALIDATE_RET( dhmin != NULL );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_init( &pem );
 
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
@@ -596,6 +630,8 @@ int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path )
     int ret;
     size_t n;
     unsigned char *buf;
+    DHM_VALIDATE_RET( dhm != NULL );
+    DHM_VALIDATE_RET( path != NULL );
 
     if( ( ret = load_file( path, &buf, &n ) ) != 0 )
         return( ret );
diff --git a/features/mbedtls/src/ecdh.c b/features/mbedtls/src/ecdh.c
index e6ae99994e..da95c60dad 100644
--- a/features/mbedtls/src/ecdh.c
+++ b/features/mbedtls/src/ecdh.c
@@ -35,9 +35,20 @@
 #if defined(MBEDTLS_ECDH_C)
 
 #include "mbedtls/ecdh.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
+/* Parameter validation macros based on platform_util.h */
+#define ECDH_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECDH_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+typedef mbedtls_ecdh_context mbedtls_ecdh_context_mbed;
+#endif
+
 #if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)
 /*
  * Generate public key (restartable version)
@@ -74,6 +85,10 @@ int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp
                      int (*f_rng)(void *, unsigned char *, size_t),
                      void *p_rng )
 {
+    ECDH_VALIDATE_RET( grp != NULL );
+    ECDH_VALIDATE_RET( d != NULL );
+    ECDH_VALIDATE_RET( Q != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
     return( ecdh_gen_public_restartable( grp, d, Q, f_rng, p_rng, NULL ) );
 }
 #endif /* !MBEDTLS_ECDH_GEN_PUBLIC_ALT */
@@ -119,48 +134,94 @@ int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
                          int (*f_rng)(void *, unsigned char *, size_t),
                          void *p_rng )
 {
+    ECDH_VALIDATE_RET( grp != NULL );
+    ECDH_VALIDATE_RET( Q != NULL );
+    ECDH_VALIDATE_RET( d != NULL );
+    ECDH_VALIDATE_RET( z != NULL );
     return( ecdh_compute_shared_restartable( grp, z, Q, d,
                                              f_rng, p_rng, NULL ) );
 }
 #endif /* !MBEDTLS_ECDH_COMPUTE_SHARED_ALT */
 
-/*
- * Initialize context
- */
-void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
+static void ecdh_init_internal( mbedtls_ecdh_context_mbed *ctx )
 {
     mbedtls_ecp_group_init( &ctx->grp );
     mbedtls_mpi_init( &ctx->d  );
     mbedtls_ecp_point_init( &ctx->Q   );
     mbedtls_ecp_point_init( &ctx->Qp  );
     mbedtls_mpi_init( &ctx->z  );
-    ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
-    mbedtls_ecp_point_init( &ctx->Vi  );
-    mbedtls_ecp_point_init( &ctx->Vf  );
-    mbedtls_mpi_init( &ctx->_d );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
-    ctx->restart_enabled = 0;
     mbedtls_ecp_restart_init( &ctx->rs );
 #endif
 }
 
 /*
- * Free context
+ * Initialize context
  */
-void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
+void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
 {
-    if( ctx == NULL )
-        return;
+    ECDH_VALIDATE( ctx != NULL );
 
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    ecdh_init_internal( ctx );
+    mbedtls_ecp_point_init( &ctx->Vi  );
+    mbedtls_ecp_point_init( &ctx->Vf  );
+    mbedtls_mpi_init( &ctx->_d );
+#else
+    memset( ctx, 0, sizeof( mbedtls_ecdh_context ) );
+
+    ctx->var = MBEDTLS_ECDH_VARIANT_NONE;
+#endif
+    ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    ctx->restart_enabled = 0;
+#endif
+}
+
+static int ecdh_setup_internal( mbedtls_ecdh_context_mbed *ctx,
+                                mbedtls_ecp_group_id grp_id )
+{
+    int ret;
+
+    ret = mbedtls_ecp_group_load( &ctx->grp, grp_id );
+    if( ret != 0 )
+    {
+        return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
+    }
+
+    return( 0 );
+}
+
+/*
+ * Setup context
+ */
+int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
+{
+    ECDH_VALIDATE_RET( ctx != NULL );
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_setup_internal( ctx, grp_id ) );
+#else
+    switch( grp_id )
+    {
+        default:
+            ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
+            ctx->var = MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0;
+            ctx->grp_id = grp_id;
+            ecdh_init_internal( &ctx->ctx.mbed_ecdh );
+            return( ecdh_setup_internal( &ctx->ctx.mbed_ecdh, grp_id ) );
+    }
+#endif
+}
+
+static void ecdh_free_internal( mbedtls_ecdh_context_mbed *ctx )
+{
     mbedtls_ecp_group_free( &ctx->grp );
     mbedtls_mpi_free( &ctx->d  );
     mbedtls_ecp_point_free( &ctx->Q   );
     mbedtls_ecp_point_free( &ctx->Qp  );
     mbedtls_mpi_free( &ctx->z  );
-    mbedtls_ecp_point_free( &ctx->Vi  );
-    mbedtls_ecp_point_free( &ctx->Vf  );
-    mbedtls_mpi_free( &ctx->_d );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     mbedtls_ecp_restart_free( &ctx->rs );
@@ -173,21 +234,49 @@ void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
  */
 void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx )
 {
+    ECDH_VALIDATE( ctx != NULL );
+
     ctx->restart_enabled = 1;
 }
 #endif
 
 /*
- * Setup and write the ServerKeyExhange parameters (RFC 4492)
- *      struct {
- *          ECParameters    curve_params;
- *          ECPoint         public;
- *      } ServerECDHParams;
+ * Free context
  */
-int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
-                      unsigned char *buf, size_t blen,
-                      int (*f_rng)(void *, unsigned char *, size_t),
-                      void *p_rng )
+void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx )
+{
+    if( ctx == NULL )
+        return;
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    mbedtls_ecp_point_free( &ctx->Vi );
+    mbedtls_ecp_point_free( &ctx->Vf );
+    mbedtls_mpi_free( &ctx->_d );
+    ecdh_free_internal( ctx );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            ecdh_free_internal( &ctx->ctx.mbed_ecdh );
+            break;
+        default:
+            break;
+    }
+
+    ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
+    ctx->var = MBEDTLS_ECDH_VARIANT_NONE;
+    ctx->grp_id = MBEDTLS_ECP_DP_NONE;
+#endif
+}
+
+static int ecdh_make_params_internal( mbedtls_ecdh_context_mbed *ctx,
+                                      size_t *olen, int point_format,
+                                      unsigned char *buf, size_t blen,
+                                      int (*f_rng)(void *,
+                                                   unsigned char *,
+                                                   size_t),
+                                      void *p_rng,
+                                      int restart_enabled )
 {
     int ret;
     size_t grp_len, pt_len;
@@ -195,12 +284,14 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
     mbedtls_ecp_restart_ctx *rs_ctx = NULL;
 #endif
 
-    if( ctx == NULL || ctx->grp.pbits == 0 )
+    if( ctx->grp.pbits == 0 )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
-    if( ctx->restart_enabled )
+    if( restart_enabled )
         rs_ctx = &ctx->rs;
+#else
+    (void) restart_enabled;
 #endif
 
 
@@ -214,14 +305,14 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
         return( ret );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
 
-    if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf, blen ) )
-                != 0 )
+    if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf,
+                                             blen ) ) != 0 )
         return( ret );
 
     buf += grp_len;
     blen -= grp_len;
 
-    if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
+    if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format,
                                              &pt_len, buf, blen ) ) != 0 )
         return( ret );
 
@@ -229,6 +320,55 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
     return( 0 );
 }
 
+/*
+ * Setup and write the ServerKeyExhange parameters (RFC 4492)
+ *      struct {
+ *          ECParameters    curve_params;
+ *          ECPoint         public;
+ *      } ServerECDHParams;
+ */
+int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
+                              unsigned char *buf, size_t blen,
+                              int (*f_rng)(void *, unsigned char *, size_t),
+                              void *p_rng )
+{
+    int restart_enabled = 0;
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    restart_enabled = ctx->restart_enabled;
+#else
+    (void) restart_enabled;
+#endif
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_make_params_internal( ctx, olen, ctx->point_format, buf, blen,
+                                       f_rng, p_rng, restart_enabled ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_make_params_internal( &ctx->ctx.mbed_ecdh, olen,
+                                               ctx->point_format, buf, blen,
+                                               f_rng, p_rng,
+                                               restart_enabled ) );
+        default:
+            return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+#endif
+}
+
+static int ecdh_read_params_internal( mbedtls_ecdh_context_mbed *ctx,
+                                      const unsigned char **buf,
+                                      const unsigned char *end )
+{
+    return( mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf,
+                                        end - *buf ) );
+}
+
 /*
  * Read the ServerKeyExhange parameters (RFC 4492)
  *      struct {
@@ -237,31 +377,43 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
  *      } ServerECDHParams;
  */
 int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
-                      const unsigned char **buf, const unsigned char *end )
+                              const unsigned char **buf,
+                              const unsigned char *end )
 {
     int ret;
+    mbedtls_ecp_group_id grp_id;
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( *buf != NULL );
+    ECDH_VALIDATE_RET( end != NULL );
 
-    if( ( ret = mbedtls_ecp_tls_read_group( &ctx->grp, buf, end - *buf ) ) != 0 )
+    if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )
+            != 0 )
         return( ret );
 
-    if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf, end - *buf ) )
-                != 0 )
+    if( ( ret = mbedtls_ecdh_setup( ctx, grp_id ) ) != 0 )
         return( ret );
 
-    return( 0 );
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_read_params_internal( ctx, buf, end ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_read_params_internal( &ctx->ctx.mbed_ecdh,
+                                               buf, end ) );
+        default:
+            return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+#endif
 }
 
-/*
- * Get parameters from a keypair
- */
-int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key,
-                     mbedtls_ecdh_side side )
+static int ecdh_get_params_internal( mbedtls_ecdh_context_mbed *ctx,
+                                     const mbedtls_ecp_keypair *key,
+                                     mbedtls_ecdh_side side )
 {
     int ret;
 
-    if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 )
-        return( ret );
-
     /* If it's not our key, just import the public part as Qp */
     if( side == MBEDTLS_ECDH_THEIRS )
         return( mbedtls_ecp_copy( &ctx->Qp, &key->Q ) );
@@ -278,29 +430,62 @@ int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypai
 }
 
 /*
- * Setup and export the client public value
+ * Get parameters from a keypair
  */
-int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
-                      unsigned char *buf, size_t blen,
-                      int (*f_rng)(void *, unsigned char *, size_t),
-                      void *p_rng )
+int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,
+                             const mbedtls_ecp_keypair *key,
+                             mbedtls_ecdh_side side )
+{
+    int ret;
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( key != NULL );
+    ECDH_VALIDATE_RET( side == MBEDTLS_ECDH_OURS ||
+                       side == MBEDTLS_ECDH_THEIRS );
+
+    if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
+        return( ret );
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_get_params_internal( ctx, key, side ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_get_params_internal( &ctx->ctx.mbed_ecdh,
+                                              key, side ) );
+        default:
+            return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+#endif
+}
+
+static int ecdh_make_public_internal( mbedtls_ecdh_context_mbed *ctx,
+                                      size_t *olen, int point_format,
+                                      unsigned char *buf, size_t blen,
+                                      int (*f_rng)(void *,
+                                                   unsigned char *,
+                                                   size_t),
+                                      void *p_rng,
+                                      int restart_enabled )
 {
     int ret;
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     mbedtls_ecp_restart_ctx *rs_ctx = NULL;
 #endif
 
-    if( ctx == NULL || ctx->grp.pbits == 0 )
+    if( ctx->grp.pbits == 0 )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
-    if( ctx->restart_enabled )
+    if( restart_enabled )
         rs_ctx = &ctx->rs;
+#else
+    (void) restart_enabled;
 #endif
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     if( ( ret = ecdh_gen_public_restartable( &ctx->grp, &ctx->d, &ctx->Q,
-                    f_rng, p_rng, rs_ctx ) ) != 0 )
+                                             f_rng, p_rng, rs_ctx ) ) != 0 )
         return( ret );
 #else
     if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q,
@@ -308,23 +493,53 @@ int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
         return( ret );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
 
-    return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
-                                olen, buf, blen );
+    return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, point_format, olen,
+                                        buf, blen );
 }
 
 /*
- * Parse and import the client's public value
+ * Setup and export the client public value
  */
-int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
-                      const unsigned char *buf, size_t blen )
+int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
+                              unsigned char *buf, size_t blen,
+                              int (*f_rng)(void *, unsigned char *, size_t),
+                              void *p_rng )
+{
+    int restart_enabled = 0;
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    restart_enabled = ctx->restart_enabled;
+#endif
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_make_public_internal( ctx, olen, ctx->point_format, buf, blen,
+                                       f_rng, p_rng, restart_enabled ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_make_public_internal( &ctx->ctx.mbed_ecdh, olen,
+                                               ctx->point_format, buf, blen,
+                                               f_rng, p_rng,
+                                               restart_enabled ) );
+        default:
+            return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+#endif
+}
+
+static int ecdh_read_public_internal( mbedtls_ecdh_context_mbed *ctx,
+                                      const unsigned char *buf, size_t blen )
 {
     int ret;
     const unsigned char *p = buf;
 
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
-
-    if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p, blen ) ) != 0 )
+    if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p,
+                                            blen ) ) != 0 )
         return( ret );
 
     if( (size_t)( p - buf ) != blen )
@@ -334,12 +549,36 @@ int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
 }
 
 /*
- * Derive and export the shared secret
+ * Parse and import the client's public value
  */
-int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
-                      unsigned char *buf, size_t blen,
-                      int (*f_rng)(void *, unsigned char *, size_t),
-                      void *p_rng )
+int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
+                              const unsigned char *buf, size_t blen )
+{
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_read_public_internal( ctx, buf, blen ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_read_public_internal( &ctx->ctx.mbed_ecdh,
+                                                       buf, blen ) );
+        default:
+            return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+#endif
+}
+
+static int ecdh_calc_secret_internal( mbedtls_ecdh_context_mbed *ctx,
+                                      size_t *olen, unsigned char *buf,
+                                      size_t blen,
+                                      int (*f_rng)(void *,
+                                                   unsigned char *,
+                                                   size_t),
+                                      void *p_rng,
+                                      int restart_enabled )
 {
     int ret;
 #if defined(MBEDTLS_ECP_RESTARTABLE)
@@ -350,13 +589,16 @@ int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
-    if( ctx->restart_enabled )
+    if( restart_enabled )
         rs_ctx = &ctx->rs;
+#else
+    (void) restart_enabled;
 #endif
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
-    if( ( ret = ecdh_compute_shared_restartable( &ctx->grp,
-                    &ctx->z, &ctx->Qp, &ctx->d, f_rng, p_rng, rs_ctx ) ) != 0 )
+    if( ( ret = ecdh_compute_shared_restartable( &ctx->grp, &ctx->z, &ctx->Qp,
+                                                 &ctx->d, f_rng, p_rng,
+                                                 rs_ctx ) ) != 0 )
     {
         return( ret );
     }
@@ -375,4 +617,37 @@ int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
     return mbedtls_mpi_write_binary( &ctx->z, buf, *olen );
 }
 
+/*
+ * Derive and export the shared secret
+ */
+int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
+                              unsigned char *buf, size_t blen,
+                              int (*f_rng)(void *, unsigned char *, size_t),
+                              void *p_rng )
+{
+    int restart_enabled = 0;
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    restart_enabled = ctx->restart_enabled;
+#endif
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    return( ecdh_calc_secret_internal( ctx, olen, buf, blen, f_rng, p_rng,
+                                       restart_enabled ) );
+#else
+    switch( ctx->var )
+    {
+        case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+            return( ecdh_calc_secret_internal( &ctx->ctx.mbed_ecdh, olen, buf,
+                                               blen, f_rng, p_rng,
+                                               restart_enabled ) );
+        default:
+            return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    }
+#endif
+}
+
 #endif /* MBEDTLS_ECDH_C */
diff --git a/features/mbedtls/src/ecdsa.c b/features/mbedtls/src/ecdsa.c
index a62c14cbe0..dc19384d61 100644
--- a/features/mbedtls/src/ecdsa.c
+++ b/features/mbedtls/src/ecdsa.c
@@ -50,6 +50,14 @@
 #define mbedtls_free       free
 #endif
 
+#include "mbedtls/platform_util.h"
+
+/* Parameter validation macros based on platform_util.h */
+#define ECDSA_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECDSA_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 
 /*
@@ -377,6 +385,13 @@ int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
                 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
+    ECDSA_VALIDATE_RET( grp   != NULL );
+    ECDSA_VALIDATE_RET( r     != NULL );
+    ECDSA_VALIDATE_RET( s     != NULL );
+    ECDSA_VALIDATE_RET( d     != NULL );
+    ECDSA_VALIDATE_RET( f_rng != NULL );
+    ECDSA_VALIDATE_RET( buf   != NULL || blen == 0 );
+
     return( ecdsa_sign_restartable( grp, r, s, d, buf, blen,
                                     f_rng, p_rng, NULL ) );
 }
@@ -456,6 +471,12 @@ int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi
                     const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
                     mbedtls_md_type_t md_alg )
 {
+    ECDSA_VALIDATE_RET( grp   != NULL );
+    ECDSA_VALIDATE_RET( r     != NULL );
+    ECDSA_VALIDATE_RET( s     != NULL );
+    ECDSA_VALIDATE_RET( d     != NULL );
+    ECDSA_VALIDATE_RET( buf   != NULL || blen == 0 );
+
     return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, NULL ) );
 }
 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
@@ -574,9 +595,17 @@ cleanup:
  * Verify ECDSA signature of hashed message
  */
 int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
-                  const unsigned char *buf, size_t blen,
-                  const mbedtls_ecp_point *Q, const mbedtls_mpi *r, const mbedtls_mpi *s)
+                          const unsigned char *buf, size_t blen,
+                          const mbedtls_ecp_point *Q,
+                          const mbedtls_mpi *r,
+                          const mbedtls_mpi *s)
 {
+    ECDSA_VALIDATE_RET( grp != NULL );
+    ECDSA_VALIDATE_RET( Q   != NULL );
+    ECDSA_VALIDATE_RET( r   != NULL );
+    ECDSA_VALIDATE_RET( s   != NULL );
+    ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
+
     return( ecdsa_verify_restartable( grp, buf, blen, Q, r, s, NULL ) );
 }
 #endif /* !MBEDTLS_ECDSA_VERIFY_ALT */
@@ -618,6 +647,10 @@ int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
 {
     int ret;
     mbedtls_mpi r, s;
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
 
     mbedtls_mpi_init( &r );
     mbedtls_mpi_init( &s );
@@ -652,12 +685,17 @@ cleanup:
 /*
  * Compute and write signature
  */
-int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t md_alg,
-                           const unsigned char *hash, size_t hlen,
-                           unsigned char *sig, size_t *slen,
-                           int (*f_rng)(void *, unsigned char *, size_t),
-                           void *p_rng )
+int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
+                                 mbedtls_md_type_t md_alg,
+                                 const unsigned char *hash, size_t hlen,
+                                 unsigned char *sig, size_t *slen,
+                                 int (*f_rng)(void *, unsigned char *, size_t),
+                                 void *p_rng )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
     return( mbedtls_ecdsa_write_signature_restartable(
                 ctx, md_alg, hash, hlen, sig, slen, f_rng, p_rng, NULL ) );
 }
@@ -669,6 +707,10 @@ int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
                                unsigned char *sig, size_t *slen,
                                mbedtls_md_type_t md_alg )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
     return( mbedtls_ecdsa_write_signature( ctx, md_alg, hash, hlen, sig, slen,
                                    NULL, NULL ) );
 }
@@ -681,6 +723,9 @@ int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
                           const unsigned char *hash, size_t hlen,
                           const unsigned char *sig, size_t slen )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
     return( mbedtls_ecdsa_read_signature_restartable(
                 ctx, hash, hlen, sig, slen, NULL ) );
 }
@@ -698,6 +743,9 @@ int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
     const unsigned char *end = sig + slen;
     size_t len;
     mbedtls_mpi r, s;
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
 
     mbedtls_mpi_init( &r );
     mbedtls_mpi_init( &s );
@@ -752,8 +800,16 @@ cleanup:
 int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
-    return( mbedtls_ecp_group_load( &ctx->grp, gid ) ||
-            mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) );
+    int ret = 0;
+    ECDSA_VALIDATE_RET( ctx   != NULL );
+    ECDSA_VALIDATE_RET( f_rng != NULL );
+
+    ret = mbedtls_ecp_group_load( &ctx->grp, gid );
+    if( ret != 0 )
+        return( ret );
+
+   return( mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d,
+                                    &ctx->Q, f_rng, p_rng ) );
 }
 #endif /* !MBEDTLS_ECDSA_GENKEY_ALT */
 
@@ -763,6 +819,8 @@ int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
 int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key )
 {
     int ret;
+    ECDSA_VALIDATE_RET( ctx != NULL );
+    ECDSA_VALIDATE_RET( key != NULL );
 
     if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ||
         ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 ||
@@ -779,6 +837,8 @@ int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_ke
  */
 void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx )
 {
+    ECDSA_VALIDATE( ctx != NULL );
+
     mbedtls_ecp_keypair_init( ctx );
 }
 
@@ -787,6 +847,9 @@ void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx )
  */
 void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_ecp_keypair_free( ctx );
 }
 
@@ -796,6 +859,8 @@ void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx )
  */
 void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
 {
+    ECDSA_VALIDATE( ctx != NULL );
+
     mbedtls_ecp_restart_init( &ctx->ecp );
 
     ctx->ver = NULL;
@@ -810,6 +875,9 @@ void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
  */
 void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_ecp_restart_free( &ctx->ecp );
 
     ecdsa_restart_ver_free( ctx->ver );
diff --git a/features/mbedtls/src/ecjpake.c b/features/mbedtls/src/ecjpake.c
index ec5a4007db..b276514e8b 100644
--- a/features/mbedtls/src/ecjpake.c
+++ b/features/mbedtls/src/ecjpake.c
@@ -33,11 +33,18 @@
 #if defined(MBEDTLS_ECJPAKE_C)
 
 #include "mbedtls/ecjpake.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
 #if !defined(MBEDTLS_ECJPAKE_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECJPAKE_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECJPAKE_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * Convert a mbedtls_ecjpake_role to identifier string
  */
@@ -54,8 +61,7 @@ static const char * const ecjpake_id[] = {
  */
 void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx )
 {
-    if( ctx == NULL )
-        return;
+    ECJPAKE_VALIDATE( ctx != NULL );
 
     ctx->md_info = NULL;
     mbedtls_ecp_group_init( &ctx->grp );
@@ -106,6 +112,11 @@ int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
 {
     int ret;
 
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( role == MBEDTLS_ECJPAKE_CLIENT ||
+                          role == MBEDTLS_ECJPAKE_SERVER );
+    ECJPAKE_VALIDATE_RET( secret != NULL || len == 0 );
+
     ctx->role = role;
 
     if( ( ctx->md_info = mbedtls_md_info_from_type( hash ) ) == NULL )
@@ -127,6 +138,8 @@ cleanup:
  */
 int mbedtls_ecjpake_check( const mbedtls_ecjpake_context *ctx )
 {
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+
     if( ctx->md_info == NULL ||
         ctx->grp.id == MBEDTLS_ECP_DP_NONE ||
         ctx->s.p == NULL )
@@ -504,6 +517,9 @@ int mbedtls_ecjpake_read_round_one( mbedtls_ecjpake_context *ctx,
                                     const unsigned char *buf,
                                     size_t len )
 {
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( buf != NULL );
+
     return( ecjpake_kkpp_read( ctx->md_info, &ctx->grp, ctx->point_format,
                                &ctx->grp.G,
                                &ctx->Xp1, &ctx->Xp2, ID_PEER,
@@ -518,6 +534,11 @@ int mbedtls_ecjpake_write_round_one( mbedtls_ecjpake_context *ctx,
                             int (*f_rng)(void *, unsigned char *, size_t),
                             void *p_rng )
 {
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     return( ecjpake_kkpp_write( ctx->md_info, &ctx->grp, ctx->point_format,
                                 &ctx->grp.G,
                                 &ctx->xm1, &ctx->Xm1, &ctx->xm2, &ctx->Xm2,
@@ -560,6 +581,9 @@ int mbedtls_ecjpake_read_round_two( mbedtls_ecjpake_context *ctx,
     mbedtls_ecp_group grp;
     mbedtls_ecp_point G;    /* C: GB, S: GA */
 
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( buf != NULL );
+
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecp_point_init( &G );
 
@@ -652,6 +676,11 @@ int mbedtls_ecjpake_write_round_two( mbedtls_ecjpake_context *ctx,
     const unsigned char *end = buf + len;
     size_t ec_len;
 
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     mbedtls_ecp_point_init( &G );
     mbedtls_ecp_point_init( &Xm );
     mbedtls_mpi_init( &xm );
@@ -727,6 +756,11 @@ int mbedtls_ecjpake_derive_secret( mbedtls_ecjpake_context *ctx,
     unsigned char kx[MBEDTLS_ECP_MAX_BYTES];
     size_t x_bytes;
 
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     *olen = mbedtls_md_get_size( ctx->md_info );
     if( len < *olen )
         return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
@@ -917,7 +951,7 @@ static const unsigned char ecjpake_test_pms[] = {
     0xb4, 0x38, 0xf7, 0x19, 0xd3, 0xc4, 0xf3, 0x51
 };
 
-/* Load my private keys and generate the correponding public keys */
+/* Load my private keys and generate the corresponding public keys */
 static int ecjpake_test_load( mbedtls_ecjpake_context *ctx,
                               const unsigned char *xm1, size_t len1,
                               const unsigned char *xm2, size_t len2 )
diff --git a/features/mbedtls/src/ecp.c b/features/mbedtls/src/ecp.c
index e3b9106dbc..ecea5910e0 100644
--- a/features/mbedtls/src/ecp.c
+++ b/features/mbedtls/src/ecp.c
@@ -47,6 +47,35 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+/**
+ * \brief Function level alternative implementation.
+ *
+ * The MBEDTLS_ECP_INTERNAL_ALT macro enables alternative implementations to
+ * replace certain functions in this module. The alternative implementations are
+ * typically hardware accelerators and need to activate the hardware before the
+ * computation starts and deactivate it after it finishes. The
+ * mbedtls_internal_ecp_init() and mbedtls_internal_ecp_free() functions serve
+ * this purpose.
+ *
+ * To preserve the correct functionality the following conditions must hold:
+ *
+ * - The alternative implementation must be activated by
+ *   mbedtls_internal_ecp_init() before any of the replaceable functions is
+ *   called.
+ * - mbedtls_internal_ecp_free() must \b only be called when the alternative
+ *   implementation is activated.
+ * - mbedtls_internal_ecp_init() must \b not be called when the alternative
+ *   implementation is activated.
+ * - Public functions must not return while the alternative implementation is
+ *   activated.
+ * - Replaceable functions are guarded by \c MBEDTLS_ECP_XXX_ALT macros and
+ *   before calling them an \code if( mbedtls_internal_ecp_grp_capable( grp ) )
+ *   \endcode ensures that the alternative implementation supports the current
+ *   group.
+ */
+#if defined(MBEDTLS_ECP_INTERNAL_ALT)
+#endif
+
 #if defined(MBEDTLS_ECP_C)
 
 #include "mbedtls/ecp.h"
@@ -57,6 +86,12 @@
 
 #if !defined(MBEDTLS_ECP_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECP_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECP_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_PLATFORM_C)
 #include "mbedtls/platform.h"
 #else
@@ -209,6 +244,7 @@ static void ecp_restart_ma_free( mbedtls_ecp_restart_muladd_ctx *ctx )
  */
 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx )
 {
+    ECP_VALIDATE( ctx != NULL );
     ctx->ops_done = 0;
     ctx->depth = 0;
     ctx->rsm = NULL;
@@ -239,6 +275,8 @@ int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp,
                               mbedtls_ecp_restart_ctx *rs_ctx,
                               unsigned ops )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+
     if( rs_ctx != NULL && ecp_max_ops != 0 )
     {
         /* scale depending on curve size: the chosen reference is 256-bit,
@@ -467,6 +505,9 @@ const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_name( const char *name
 {
     const mbedtls_ecp_curve_info *curve_info;
 
+    if( name == NULL )
+        return( NULL );
+
     for( curve_info = mbedtls_ecp_curve_list();
          curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
          curve_info++ )
@@ -497,8 +538,7 @@ static inline ecp_curve_type ecp_get_type( const mbedtls_ecp_group *grp )
  */
 void mbedtls_ecp_point_init( mbedtls_ecp_point *pt )
 {
-    if( pt == NULL )
-        return;
+    ECP_VALIDATE( pt != NULL );
 
     mbedtls_mpi_init( &pt->X );
     mbedtls_mpi_init( &pt->Y );
@@ -510,8 +550,7 @@ void mbedtls_ecp_point_init( mbedtls_ecp_point *pt )
  */
 void mbedtls_ecp_group_init( mbedtls_ecp_group *grp )
 {
-    if( grp == NULL )
-        return;
+    ECP_VALIDATE( grp != NULL );
 
     grp->id = MBEDTLS_ECP_DP_NONE;
     mbedtls_mpi_init( &grp->P );
@@ -535,8 +574,7 @@ void mbedtls_ecp_group_init( mbedtls_ecp_group *grp )
  */
 void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key )
 {
-    if( key == NULL )
-        return;
+    ECP_VALIDATE( key != NULL );
 
     mbedtls_ecp_group_init( &key->grp );
     mbedtls_mpi_init( &key->d );
@@ -604,6 +642,8 @@ void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key )
 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q )
 {
     int ret;
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( Q != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->X, &Q->X ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->Y, &Q->Y ) );
@@ -618,7 +658,10 @@ cleanup:
  */
 int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src )
 {
-    return mbedtls_ecp_group_load( dst, src->id );
+    ECP_VALIDATE_RET( dst != NULL );
+    ECP_VALIDATE_RET( src != NULL );
+
+    return( mbedtls_ecp_group_load( dst, src->id ) );
 }
 
 /*
@@ -627,6 +670,7 @@ int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src
 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt )
 {
     int ret;
+    ECP_VALIDATE_RET( pt != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->X , 1 ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Y , 1 ) );
@@ -641,15 +685,20 @@ cleanup:
  */
 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt )
 {
+    ECP_VALIDATE_RET( pt != NULL );
+
     return( mbedtls_mpi_cmp_int( &pt->Z, 0 ) == 0 );
 }
 
 /*
- * Compare two points lazyly
+ * Compare two points lazily
  */
 int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P,
                            const mbedtls_ecp_point *Q )
 {
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( Q != NULL );
+
     if( mbedtls_mpi_cmp_mpi( &P->X, &Q->X ) == 0 &&
         mbedtls_mpi_cmp_mpi( &P->Y, &Q->Y ) == 0 &&
         mbedtls_mpi_cmp_mpi( &P->Z, &Q->Z ) == 0 )
@@ -667,6 +716,9 @@ int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix,
                            const char *x, const char *y )
 {
     int ret;
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( x != NULL );
+    ECP_VALIDATE_RET( y != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->X, radix, x ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->Y, radix, y ) );
@@ -679,16 +731,19 @@ cleanup:
 /*
  * Export a point into unsigned binary data (SEC1 2.3.3)
  */
-int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P,
-                            int format, size_t *olen,
-                            unsigned char *buf, size_t buflen )
+int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp,
+                                    const mbedtls_ecp_point *P,
+                                    int format, size_t *olen,
+                                    unsigned char *buf, size_t buflen )
 {
     int ret = 0;
     size_t plen;
-
-    if( format != MBEDTLS_ECP_PF_UNCOMPRESSED &&
-        format != MBEDTLS_ECP_PF_COMPRESSED )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( P    != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( format == MBEDTLS_ECP_PF_UNCOMPRESSED ||
+                      format == MBEDTLS_ECP_PF_COMPRESSED );
 
     /*
      * Common case: P == 0
@@ -735,11 +790,15 @@ cleanup:
 /*
  * Import a point from unsigned binary data (SEC1 2.3.4)
  */
-int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                           const unsigned char *buf, size_t ilen )
+int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp,
+                                   mbedtls_ecp_point *pt,
+                                   const unsigned char *buf, size_t ilen )
 {
     int ret;
     size_t plen;
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+    ECP_VALIDATE_RET( buf != NULL );
 
     if( ilen < 1 )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
@@ -774,11 +833,16 @@ cleanup:
  *          opaque point <1..2^8-1>;
  *      } ECPoint;
  */
-int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                        const unsigned char **buf, size_t buf_len )
+int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp,
+                                mbedtls_ecp_point *pt,
+                                const unsigned char **buf, size_t buf_len )
 {
     unsigned char data_len;
     const unsigned char *buf_start;
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+    ECP_VALIDATE_RET( buf != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
 
     /*
      * We must have at least two bytes (1 for length, at least one for data)
@@ -796,7 +860,7 @@ int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point
     buf_start = *buf;
     *buf += data_len;
 
-    return mbedtls_ecp_point_read_binary( grp, pt, buf_start, data_len );
+    return( mbedtls_ecp_point_read_binary( grp, pt, buf_start, data_len ) );
 }
 
 /*
@@ -810,6 +874,12 @@ int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, const mbedtls_ecp
                          unsigned char *buf, size_t blen )
 {
     int ret;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( pt   != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( format == MBEDTLS_ECP_PF_UNCOMPRESSED ||
+                      format == MBEDTLS_ECP_PF_COMPRESSED );
 
     /*
      * buffer length must be at least one, for our length byte
@@ -833,10 +903,33 @@ int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, const mbedtls_ecp
 /*
  * Set a group from an ECParameters record (RFC 4492)
  */
-int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, const unsigned char **buf, size_t len )
+int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp,
+                                const unsigned char **buf, size_t len )
+{
+    int ret;
+    mbedtls_ecp_group_id grp_id;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
+
+    if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, len ) ) != 0 )
+        return( ret );
+
+    return( mbedtls_ecp_group_load( grp, grp_id ) );
+}
+
+/*
+ * Read a group id from an ECParameters record (RFC 4492) and convert it to
+ * mbedtls_ecp_group_id.
+ */
+int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp,
+                                   const unsigned char **buf, size_t len )
 {
     uint16_t tls_id;
     const mbedtls_ecp_curve_info *curve_info;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
 
     /*
      * We expect at least three bytes (see below)
@@ -860,7 +953,9 @@ int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, const unsigned char **bu
     if( ( curve_info = mbedtls_ecp_curve_info_from_tls_id( tls_id ) ) == NULL )
         return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
 
-    return mbedtls_ecp_group_load( grp, curve_info->grp_id );
+    *grp = curve_info->grp_id;
+
+    return( 0 );
 }
 
 /*
@@ -870,6 +965,9 @@ int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
                          unsigned char *buf, size_t blen )
 {
     const mbedtls_ecp_curve_info *curve_info;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
 
     if( ( curve_info = mbedtls_ecp_curve_info_from_grp_id( grp->id ) ) == NULL )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
@@ -2228,6 +2326,10 @@ int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
 #if defined(MBEDTLS_ECP_INTERNAL_ALT)
     char is_grp_capable = 0;
 #endif
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     /* reset ops count for this call if top-level */
@@ -2285,6 +2387,10 @@ int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
     return( mbedtls_ecp_mul_restartable( grp, R, m, P, f_rng, p_rng, NULL ) );
 }
 
@@ -2387,6 +2493,12 @@ int mbedtls_ecp_muladd_restartable(
 #if defined(MBEDTLS_ECP_INTERNAL_ALT)
     char is_grp_capable = 0;
 #endif
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
+    ECP_VALIDATE_RET( n   != NULL );
+    ECP_VALIDATE_RET( Q   != NULL );
 
     if( ecp_get_type( grp ) != ECP_TYPE_SHORT_WEIERSTRASS )
         return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
@@ -2469,6 +2581,12 @@ int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
              const mbedtls_mpi *n, const mbedtls_ecp_point *Q )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
+    ECP_VALIDATE_RET( n   != NULL );
+    ECP_VALIDATE_RET( Q   != NULL );
     return( mbedtls_ecp_muladd_restartable( grp, R, m, P, n, Q, NULL ) );
 }
 
@@ -2491,8 +2609,12 @@ static int ecp_check_pubkey_mx( const mbedtls_ecp_group *grp, const mbedtls_ecp_
 /*
  * Check that a point is valid as a public key
  */
-int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt )
+int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp,
+                              const mbedtls_ecp_point *pt )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+
     /* Must use affine coordinates */
     if( mbedtls_mpi_cmp_int( &pt->Z, 1 ) != 0 )
         return( MBEDTLS_ERR_ECP_INVALID_KEY );
@@ -2511,8 +2633,12 @@ int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_po
 /*
  * Check that an mbedtls_mpi is valid as a private key
  */
-int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, const mbedtls_mpi *d )
+int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp,
+                               const mbedtls_mpi *d )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( d   != NULL );
+
 #if defined(ECP_MONTGOMERY)
     if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
     {
@@ -2553,7 +2679,13 @@ int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp,
                      void *p_rng )
 {
     int ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
-    size_t n_size = ( grp->nbits + 7 ) / 8;
+    size_t n_size;
+
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
+
+    n_size = ( grp->nbits + 7 ) / 8;
 
 #if defined(ECP_MONTGOMERY)
     if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
@@ -2632,6 +2764,11 @@ int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
                      void *p_rng )
 {
     int ret;
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( G     != NULL );
+    ECP_VALIDATE_RET( Q     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, d, f_rng, p_rng ) );
     MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, Q, d, G, f_rng, p_rng ) );
@@ -2648,6 +2785,11 @@ int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp,
                              int (*f_rng)(void *, unsigned char *, size_t),
                              void *p_rng )
 {
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( Q     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
+
     return( mbedtls_ecp_gen_keypair_base( grp, &grp->G, d, Q, f_rng, p_rng ) );
 }
 
@@ -2658,6 +2800,8 @@ int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     int ret;
+    ECP_VALIDATE_RET( key   != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
 
     if( ( ret = mbedtls_ecp_group_load( &key->grp, grp_id ) ) != 0 )
         return( ret );
@@ -2673,6 +2817,8 @@ int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, const mbedtls_ec
     int ret;
     mbedtls_ecp_point Q;
     mbedtls_ecp_group grp;
+    ECP_VALIDATE_RET( pub != NULL );
+    ECP_VALIDATE_RET( prv != NULL );
 
     if( pub->grp.id == MBEDTLS_ECP_DP_NONE ||
         pub->grp.id != prv->grp.id ||
diff --git a/features/mbedtls/src/ecp_curves.c b/features/mbedtls/src/ecp_curves.c
index 68e2441ae8..731621dc3c 100644
--- a/features/mbedtls/src/ecp_curves.c
+++ b/features/mbedtls/src/ecp_curves.c
@@ -28,11 +28,18 @@
 #if defined(MBEDTLS_ECP_C)
 
 #include "mbedtls/ecp.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
 #if !defined(MBEDTLS_ECP_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECP_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECP_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
 #define inline __inline
@@ -746,6 +753,7 @@ cleanup:
  */
 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id )
 {
+    ECP_VALIDATE_RET( grp != NULL );
     mbedtls_ecp_group_free( grp );
 
     grp->id = id;
diff --git a/features/mbedtls/src/entropy_poll.c b/features/mbedtls/src/entropy_poll.c
index 040aa117dc..4556f88a55 100644
--- a/features/mbedtls/src/entropy_poll.c
+++ b/features/mbedtls/src/entropy_poll.c
@@ -99,6 +99,7 @@ int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len
 #include <sys/syscall.h>
 #if defined(SYS_getrandom)
 #define HAVE_GETRANDOM
+#include <errno.h>
 
 static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
 {
@@ -108,47 +109,8 @@ static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
     memset( buf, 0, buflen );
 #endif
 #endif
-
     return( syscall( SYS_getrandom, buf, buflen, flags ) );
 }
-
-#include <sys/utsname.h>
-/* Check if version is at least 3.17.0 */
-static int check_version_3_17_plus( void )
-{
-    int minor;
-    struct utsname un;
-    const char *ver;
-
-    /* Get version information */
-    uname(&un);
-    ver = un.release;
-
-    /* Check major version; assume a single digit */
-    if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' )
-        return( -1 );
-
-    if( ver[0] - '0' > 3 )
-        return( 0 );
-
-    /* Ok, so now we know major == 3, check minor.
-     * Assume 1 or 2 digits. */
-    if( ver[2] < '0' || ver[2] > '9' )
-        return( -1 );
-
-    minor = ver[2] - '0';
-
-    if( ver[3] >= '0' && ver[3] <= '9' )
-        minor = 10 * minor + ver[3] - '0';
-    else if( ver [3] != '.' )
-        return( -1 );
-
-    if( minor < 17 )
-        return( -1 );
-
-    return( 0 );
-}
-static int has_getrandom = -1;
 #endif /* SYS_getrandom */
 #endif /* __linux__ */
 
@@ -159,22 +121,21 @@ int mbedtls_platform_entropy_poll( void *data,
 {
     FILE *file;
     size_t read_len;
+    int ret;
     ((void) data);
 
 #if defined(HAVE_GETRANDOM)
-    if( has_getrandom == -1 )
-        has_getrandom = ( check_version_3_17_plus() == 0 );
-
-    if( has_getrandom )
+    ret = getrandom_wrapper( output, len, 0 );
+    if( ret >= 0 )
     {
-        int ret;
-
-        if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
-            return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
-
         *olen = ret;
         return( 0 );
     }
+    else if( errno != ENOSYS )
+        return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
+    /* Fall through if the system call isn't known. */
+#else
+    ((void) ret);
 #endif /* HAVE_GETRANDOM */
 
     *olen = 0;
diff --git a/features/mbedtls/src/error.c b/features/mbedtls/src/error.c
index eabee9e21b..c596f0bcc5 100644
--- a/features/mbedtls/src/error.c
+++ b/features/mbedtls/src/error.c
@@ -567,7 +567,7 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen )
         if( use_ret == -(MBEDTLS_ERR_X509_BUFFER_TOO_SMALL) )
             mbedtls_snprintf( buf, buflen, "X509 - Destination buffer is too small" );
         if( use_ret == -(MBEDTLS_ERR_X509_FATAL_ERROR) )
-            mbedtls_snprintf( buf, buflen, "X509 - A fatal error occured, eg the chain is too long or the vrfy callback failed" );
+            mbedtls_snprintf( buf, buflen, "X509 - A fatal error occurred, eg the chain is too long or the vrfy callback failed" );
 #endif /* MBEDTLS_X509_USE_C || MBEDTLS_X509_CREATE_C */
         // END generated code
 
@@ -618,8 +618,8 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen )
 #endif /* MBEDTLS_ARC4_C */
 
 #if defined(MBEDTLS_ARIA_C)
-    if( use_ret == -(MBEDTLS_ERR_ARIA_INVALID_KEY_LENGTH) )
-        mbedtls_snprintf( buf, buflen, "ARIA - Invalid key length" );
+    if( use_ret == -(MBEDTLS_ERR_ARIA_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "ARIA - Bad input data" );
     if( use_ret == -(MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH) )
         mbedtls_snprintf( buf, buflen, "ARIA - Invalid data input length" );
     if( use_ret == -(MBEDTLS_ERR_ARIA_FEATURE_UNAVAILABLE) )
@@ -672,17 +672,17 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen )
 #endif /* MBEDTLS_BIGNUM_C */
 
 #if defined(MBEDTLS_BLOWFISH_C)
-    if( use_ret == -(MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH) )
-        mbedtls_snprintf( buf, buflen, "BLOWFISH - Invalid key length" );
-    if( use_ret == -(MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED) )
-        mbedtls_snprintf( buf, buflen, "BLOWFISH - Blowfish hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "BLOWFISH - Bad input data" );
     if( use_ret == -(MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH) )
         mbedtls_snprintf( buf, buflen, "BLOWFISH - Invalid data input length" );
+    if( use_ret == -(MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED) )
+        mbedtls_snprintf( buf, buflen, "BLOWFISH - Blowfish hardware accelerator failed" );
 #endif /* MBEDTLS_BLOWFISH_C */
 
 #if defined(MBEDTLS_CAMELLIA_C)
-    if( use_ret == -(MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH) )
-        mbedtls_snprintf( buf, buflen, "CAMELLIA - Invalid key length" );
+    if( use_ret == -(MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "CAMELLIA - Bad input data" );
     if( use_ret == -(MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH) )
         mbedtls_snprintf( buf, buflen, "CAMELLIA - Invalid data input length" );
     if( use_ret == -(MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED) )
@@ -855,16 +855,22 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen )
 #if defined(MBEDTLS_SHA1_C)
     if( use_ret == -(MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA1 - SHA-1 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA1_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA1 - SHA-1 input data was malformed" );
 #endif /* MBEDTLS_SHA1_C */
 
 #if defined(MBEDTLS_SHA256_C)
     if( use_ret == -(MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA256 - SHA-256 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA256_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA256 - SHA-256 input data was malformed" );
 #endif /* MBEDTLS_SHA256_C */
 
 #if defined(MBEDTLS_SHA512_C)
     if( use_ret == -(MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA512 - SHA-512 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA512_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA512 - SHA-512 input data was malformed" );
 #endif /* MBEDTLS_SHA512_C */
 
 #if defined(MBEDTLS_THREADING_C)
diff --git a/features/mbedtls/src/gcm.c b/features/mbedtls/src/gcm.c
index c486ef765d..675926a518 100644
--- a/features/mbedtls/src/gcm.c
+++ b/features/mbedtls/src/gcm.c
@@ -57,6 +57,12 @@
 
 #if !defined(MBEDTLS_GCM_ALT)
 
+/* Parameter validation macros */
+#define GCM_VALIDATE_RET( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_GCM_BAD_INPUT )
+#define GCM_VALIDATE( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -85,6 +91,7 @@
  */
 void mbedtls_gcm_init( mbedtls_gcm_context *ctx )
 {
+    GCM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_gcm_context ) );
 }
 
@@ -164,6 +171,10 @@ int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
     int ret;
     const mbedtls_cipher_info_t *cipher_info;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( key != NULL );
+    GCM_VALIDATE_RET( keybits == 128 || keybits == 192 || keybits == 256 );
+
     cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
     if( cipher_info == NULL )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
@@ -274,6 +285,10 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
     const unsigned char *p;
     size_t use_len, olen = 0;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+
     /* IV and AD are limited to 2^64 bits, so 2^61 bytes */
     /* IV is not allowed to be zero length */
     if( iv_len == 0 ||
@@ -356,6 +371,10 @@ int mbedtls_gcm_update( mbedtls_gcm_context *ctx,
     unsigned char *out_p = output;
     size_t use_len, olen = 0;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+
     if( output > input && (size_t) ( output - input ) < length )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
 
@@ -409,8 +428,14 @@ int mbedtls_gcm_finish( mbedtls_gcm_context *ctx,
 {
     unsigned char work_buf[16];
     size_t i;
-    uint64_t orig_len = ctx->len * 8;
-    uint64_t orig_add_len = ctx->add_len * 8;
+    uint64_t orig_len;
+    uint64_t orig_add_len;
+
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+
+    orig_len = ctx->len * 8;
+    orig_add_len = ctx->add_len * 8;
 
     if( tag_len > 16 || tag_len < 4 )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
@@ -452,6 +477,13 @@ int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
 {
     int ret;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+
     if( ( ret = mbedtls_gcm_starts( ctx, mode, iv, iv_len, add, add_len ) ) != 0 )
         return( ret );
 
@@ -480,6 +512,13 @@ int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
     size_t i;
     int diff;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+
     if( ( ret = mbedtls_gcm_crypt_and_tag( ctx, MBEDTLS_GCM_DECRYPT, length,
                                    iv, iv_len, add, add_len,
                                    input, output, tag_len, check_tag ) ) != 0 )
@@ -502,6 +541,8 @@ int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
 
 void mbedtls_gcm_free( mbedtls_gcm_context *ctx )
 {
+    if( ctx == NULL )
+        return;
     mbedtls_cipher_free( &ctx->cipher_ctx );
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_gcm_context ) );
 }
diff --git a/features/mbedtls/src/hmac_drbg.c b/features/mbedtls/src/hmac_drbg.c
index dad55ff861..c50330e7d8 100644
--- a/features/mbedtls/src/hmac_drbg.c
+++ b/features/mbedtls/src/hmac_drbg.c
@@ -66,31 +66,60 @@ void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
 /*
  * HMAC_DRBG update, using optional additional data (10.1.2.2)
  */
-void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
-                       const unsigned char *additional, size_t add_len )
+int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
+                                  const unsigned char *additional,
+                                  size_t add_len )
 {
     size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
     unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
     unsigned char sep[1];
     unsigned char K[MBEDTLS_MD_MAX_SIZE];
+    int ret;
 
     for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
     {
         /* Step 1 or 4 */
-        mbedtls_md_hmac_reset( &ctx->md_ctx );
-        mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
-        mbedtls_md_hmac_update( &ctx->md_ctx, sep, 1 );
+        if( ( ret = mbedtls_md_hmac_reset( &ctx->md_ctx ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
+                                            ctx->V, md_len ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
+                                            sep, 1 ) ) != 0 )
+            goto exit;
         if( rounds == 2 )
-            mbedtls_md_hmac_update( &ctx->md_ctx, additional, add_len );
-        mbedtls_md_hmac_finish( &ctx->md_ctx, K );
+        {
+            if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
+                                                additional, add_len ) ) != 0 )
+            goto exit;
+        }
+        if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, K ) ) != 0 )
+            goto exit;
 
         /* Step 2 or 5 */
-        mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len );
-        mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
-        mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
+        if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
+                                            ctx->V, md_len ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V ) ) != 0 )
+            goto exit;
     }
+
+exit:
+    mbedtls_platform_zeroize( K, sizeof( K ) );
+    return( ret );
 }
 
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
+                               const unsigned char *additional,
+                               size_t add_len )
+{
+    (void) mbedtls_hmac_drbg_update_ret( ctx, additional, add_len );
+}
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
 /*
  * Simplified HMAC_DRBG initialisation (for use with deterministic ECDSA)
  */
@@ -108,10 +137,13 @@ int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
      * Use the V memory location, which is currently all 0, to initialize the
      * MD context with an all-zero key. Then set V to its initial value.
      */
-    mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, mbedtls_md_get_size( md_info ) );
+    if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V,
+                                        mbedtls_md_get_size( md_info ) ) ) != 0 )
+        return( ret );
     memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
 
-    mbedtls_hmac_drbg_update( ctx, data, data_len );
+    if( ( ret = mbedtls_hmac_drbg_update_ret( ctx, data, data_len ) ) != 0 )
+        return( ret );
 
     return( 0 );
 }
@@ -124,6 +156,7 @@ int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
 {
     unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
     size_t seedlen;
+    int ret;
 
     /* III. Check input length */
     if( len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
@@ -135,7 +168,8 @@ int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
     memset( seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
 
     /* IV. Gather entropy_len bytes of entropy for the seed */
-    if( ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) != 0 )
+    if( ( ret = ctx->f_entropy( ctx->p_entropy,
+                                seed, ctx->entropy_len ) ) != 0 )
         return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
 
     seedlen = ctx->entropy_len;
@@ -148,13 +182,16 @@ int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
     }
 
     /* 2. Update state */
-    mbedtls_hmac_drbg_update( ctx, seed, seedlen );
+    if( ( ret = mbedtls_hmac_drbg_update_ret( ctx, seed, seedlen ) ) != 0 )
+        goto exit;
 
     /* 3. Reset reseed_counter */
     ctx->reseed_counter = 1;
 
+exit:
     /* 4. Done */
-    return( 0 );
+    mbedtls_platform_zeroize( seed, seedlen );
+    return( ret );
 }
 
 /*
@@ -180,7 +217,8 @@ int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
      * Use the V memory location, which is currently all 0, to initialize the
      * MD context with an all-zero key. Then set V to its initial value.
      */
-    mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size );
+    if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size ) ) != 0 )
+        return( ret );
     memset( ctx->V, 0x01, md_size );
 
     ctx->f_entropy = f_entropy;
@@ -273,16 +311,24 @@ int mbedtls_hmac_drbg_random_with_add( void *p_rng,
 
     /* 2. Use additional data if any */
     if( additional != NULL && add_len != 0 )
-        mbedtls_hmac_drbg_update( ctx, additional, add_len );
+    {
+        if( ( ret = mbedtls_hmac_drbg_update_ret( ctx,
+                                                  additional, add_len ) ) != 0 )
+            goto exit;
+    }
 
     /* 3, 4, 5. Generate bytes */
     while( left != 0 )
     {
         size_t use_len = left > md_len ? md_len : left;
 
-        mbedtls_md_hmac_reset( &ctx->md_ctx );
-        mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
-        mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
+        if( ( ret = mbedtls_md_hmac_reset( &ctx->md_ctx ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
+                                            ctx->V, md_len ) ) != 0 )
+            goto exit;
+        if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V ) ) != 0 )
+            goto exit;
 
         memcpy( out, ctx->V, use_len );
         out += use_len;
@@ -290,13 +336,16 @@ int mbedtls_hmac_drbg_random_with_add( void *p_rng,
     }
 
     /* 6. Update */
-    mbedtls_hmac_drbg_update( ctx, additional, add_len );
+    if( ( ret = mbedtls_hmac_drbg_update_ret( ctx,
+                                              additional, add_len ) ) != 0 )
+        goto exit;
 
     /* 7. Update reseed counter */
     ctx->reseed_counter++;
 
+exit:
     /* 8. Done */
-    return( 0 );
+    return( ret );
 }
 
 /*
@@ -368,35 +417,36 @@ exit:
 int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
 {
     int ret = 0;
-    FILE *f;
+    FILE *f = NULL;
     size_t n;
     unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
+    unsigned char c;
 
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
 
-    fseek( f, 0, SEEK_END );
-    n = (size_t) ftell( f );
-    fseek( f, 0, SEEK_SET );
-
-    if( n > MBEDTLS_HMAC_DRBG_MAX_INPUT )
+    n = fread( buf, 1, sizeof( buf ), f );
+    if( fread( &c, 1, 1, f ) != 0 )
     {
-        fclose( f );
-        return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
+        ret = MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG;
+        goto exit;
     }
-
-    if( fread( buf, 1, n, f ) != n )
+    if( n == 0 || ferror( f ) )
+    {
         ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
-    else
-        mbedtls_hmac_drbg_update( ctx, buf, n );
-
+        goto exit;
+    }
     fclose( f );
+    f = NULL;
 
+    ret = mbedtls_hmac_drbg_update_ret( ctx, buf, n );
+
+exit:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
-
+    if( f != NULL )
+        fclose( f );
     if( ret != 0 )
         return( ret );
-
     return( mbedtls_hmac_drbg_write_seed_file( ctx, path ) );
 }
 #endif /* MBEDTLS_FS_IO */
diff --git a/features/mbedtls/src/nist_kw.c b/features/mbedtls/src/nist_kw.c
index 176af9fe08..317a2426ae 100644
--- a/features/mbedtls/src/nist_kw.c
+++ b/features/mbedtls/src/nist_kw.c
@@ -311,7 +311,7 @@ cleanup:
     }
     mbedtls_platform_zeroize( inbuff, KW_SEMIBLOCK_LENGTH * 2 );
     mbedtls_platform_zeroize( outbuff, KW_SEMIBLOCK_LENGTH * 2 );
-    mbedtls_cipher_finish( &ctx->cipher_ctx, NULL, &olen );
+
     return( ret );
 }
 
@@ -528,7 +528,7 @@ cleanup:
     mbedtls_platform_zeroize( &bad_padding, sizeof( bad_padding) );
     mbedtls_platform_zeroize( &diff, sizeof( diff ) );
     mbedtls_platform_zeroize( A, sizeof( A ) );
-    mbedtls_cipher_finish( &ctx->cipher_ctx, NULL, &olen );
+
     return( ret );
 }
 
diff --git a/features/mbedtls/src/pem.c b/features/mbedtls/src/pem.c
index 6069a23dec..897c8a0d6f 100644
--- a/features/mbedtls/src/pem.c
+++ b/features/mbedtls/src/pem.c
@@ -423,9 +423,11 @@ int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const
 
 void mbedtls_pem_free( mbedtls_pem_context *ctx )
 {
-    if( ctx->buf != NULL )
+    if ( ctx->buf != NULL )
+    {
         mbedtls_platform_zeroize( ctx->buf, ctx->buflen );
-    mbedtls_free( ctx->buf );
+        mbedtls_free( ctx->buf );
+    }
     mbedtls_free( ctx->info );
 
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pem_context ) );
diff --git a/features/mbedtls/src/pk.c b/features/mbedtls/src/pk.c
index 989ed095b2..a1e278e738 100644
--- a/features/mbedtls/src/pk.c
+++ b/features/mbedtls/src/pk.c
@@ -48,13 +48,18 @@
 #include <limits.h>
 #include <stdint.h>
 
+/* Parameter validation macros based on platform_util.h */
+#define PK_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
+#define PK_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * Initialise a mbedtls_pk_context
  */
 void mbedtls_pk_init( mbedtls_pk_context *ctx )
 {
-    if( ctx == NULL )
-        return;
+    PK_VALIDATE( ctx != NULL );
 
     ctx->pk_info = NULL;
     ctx->pk_ctx = NULL;
@@ -65,10 +70,11 @@ void mbedtls_pk_init( mbedtls_pk_context *ctx )
  */
 void mbedtls_pk_free( mbedtls_pk_context *ctx )
 {
-    if( ctx == NULL || ctx->pk_info == NULL )
+    if( ctx == NULL )
         return;
 
-    ctx->pk_info->ctx_free_func( ctx->pk_ctx );
+    if ( ctx->pk_info != NULL )
+        ctx->pk_info->ctx_free_func( ctx->pk_ctx );
 
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pk_context ) );
 }
@@ -79,6 +85,7 @@ void mbedtls_pk_free( mbedtls_pk_context *ctx )
  */
 void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx )
 {
+    PK_VALIDATE( ctx != NULL );
     ctx->pk_info = NULL;
     ctx->rs_ctx = NULL;
 }
@@ -132,7 +139,8 @@ const mbedtls_pk_info_t * mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type )
  */
 int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info )
 {
-    if( ctx == NULL || info == NULL || ctx->pk_info != NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    if( info == NULL || ctx->pk_info != NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
@@ -147,10 +155,10 @@ int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info )
 /*
  * Initialise a PSA-wrapping context
  */
-int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_slot_t key )
+int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_handle_t key )
 {
     const mbedtls_pk_info_t * const info = &mbedtls_pk_opaque_info;
-    psa_key_slot_t *pk_ctx;
+    psa_key_handle_t *pk_ctx;
     psa_key_type_t type;
 
     if( ctx == NULL || ctx->pk_info != NULL )
@@ -168,7 +176,7 @@ int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_slot_t key )
 
     ctx->pk_info = info;
 
-    pk_ctx = (psa_key_slot_t *) ctx->pk_ctx;
+    pk_ctx = (psa_key_handle_t *) ctx->pk_ctx;
     *pk_ctx = key;
 
     return( 0 );
@@ -187,7 +195,8 @@ int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
     mbedtls_rsa_alt_context *rsa_alt;
     const mbedtls_pk_info_t *info = &mbedtls_rsa_alt_info;
 
-    if( ctx == NULL || ctx->pk_info != NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    if( ctx->pk_info != NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
@@ -211,7 +220,9 @@ int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
  */
 int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type )
 {
-    /* null or NONE context can't do anything */
+    /* A context with null pk_info is not set up yet and can't do anything.
+     * For backward compatibility, also accept NULL instead of a context
+     * pointer. */
     if( ctx == NULL || ctx->pk_info == NULL )
         return( 0 );
 
@@ -268,7 +279,12 @@ int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx,
                const unsigned char *sig, size_t sig_len,
                mbedtls_pk_restart_ctx *rs_ctx )
 {
-    if( ctx == NULL || ctx->pk_info == NULL ||
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
+                     hash != NULL );
+    PK_VALIDATE_RET( sig != NULL );
+
+    if( ctx->pk_info == NULL ||
         pk_hashlen_helper( md_alg, &hash_len ) != 0 )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
@@ -321,7 +337,12 @@ int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options,
                    const unsigned char *hash, size_t hash_len,
                    const unsigned char *sig, size_t sig_len )
 {
-    if( ctx == NULL || ctx->pk_info == NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
+                     hash != NULL );
+    PK_VALIDATE_RET( sig != NULL );
+
+    if( ctx->pk_info == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ! mbedtls_pk_can_do( ctx, type ) )
@@ -381,7 +402,12 @@ int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
              mbedtls_pk_restart_ctx *rs_ctx )
 {
-    if( ctx == NULL || ctx->pk_info == NULL ||
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
+                     hash != NULL );
+    PK_VALIDATE_RET( sig != NULL );
+
+    if( ctx->pk_info == NULL ||
         pk_hashlen_helper( md_alg, &hash_len ) != 0 )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
@@ -435,7 +461,12 @@ int mbedtls_pk_decrypt( mbedtls_pk_context *ctx,
                 unsigned char *output, size_t *olen, size_t osize,
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
-    if( ctx == NULL || ctx->pk_info == NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( input != NULL || ilen == 0 );
+    PK_VALIDATE_RET( output != NULL || osize == 0 );
+    PK_VALIDATE_RET( olen != NULL );
+
+    if( ctx->pk_info == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ctx->pk_info->decrypt_func == NULL )
@@ -453,7 +484,12 @@ int mbedtls_pk_encrypt( mbedtls_pk_context *ctx,
                 unsigned char *output, size_t *olen, size_t osize,
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
-    if( ctx == NULL || ctx->pk_info == NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( input != NULL || ilen == 0 );
+    PK_VALIDATE_RET( output != NULL || osize == 0 );
+    PK_VALIDATE_RET( olen != NULL );
+
+    if( ctx->pk_info == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ctx->pk_info->encrypt_func == NULL )
@@ -468,8 +504,11 @@ int mbedtls_pk_encrypt( mbedtls_pk_context *ctx,
  */
 int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_context *prv )
 {
-    if( pub == NULL || pub->pk_info == NULL ||
-        prv == NULL || prv->pk_info == NULL )
+    PK_VALIDATE_RET( pub != NULL );
+    PK_VALIDATE_RET( prv != NULL );
+
+    if( pub->pk_info == NULL ||
+        prv->pk_info == NULL )
     {
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
     }
@@ -496,6 +535,8 @@ int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_conte
  */
 size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx )
 {
+    /* For backward compatibility, accept NULL or a context that
+     * isn't set up yet, and return a fake value that should be safe. */
     if( ctx == NULL || ctx->pk_info == NULL )
         return( 0 );
 
@@ -507,7 +548,8 @@ size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx )
  */
 int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items )
 {
-    if( ctx == NULL || ctx->pk_info == NULL )
+    PK_VALIDATE_RET( ctx != NULL );
+    if( ctx->pk_info == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
     if( ctx->pk_info->debug_func == NULL )
@@ -547,13 +589,13 @@ mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx )
  * Currently only works for EC private keys.
  */
 int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
-                               psa_key_slot_t *slot,
+                               psa_key_handle_t *slot,
                                psa_algorithm_t hash_alg )
 {
 #if !defined(MBEDTLS_ECP_C)
     return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
 #else
-    psa_key_slot_t key;
+    psa_key_handle_t key;
     const mbedtls_ecp_keypair *ec;
     unsigned char d[MBEDTLS_ECP_MAX_BYTES];
     size_t d_len;
@@ -572,20 +614,21 @@ int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
         return( ret );
 
     curve_id = mbedtls_ecp_curve_info_from_grp_id( ec->grp.id )->tls_id;
+    key_type = PSA_KEY_TYPE_ECC_KEYPAIR(
+                                 mbedtls_psa_parse_tls_ecc_group ( curve_id ) );
 
-    /* find a free key slot */
-    if( PSA_SUCCESS != mbedtls_psa_get_free_key_slot( &key ) )
+    /* allocate a key slot */
+    if( PSA_SUCCESS != psa_allocate_key( &key ) )
         return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
 
     /* set policy */
-    psa_key_policy_init( &policy );
+    policy = psa_key_policy_init();
     psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_SIGN,
                                        PSA_ALG_ECDSA(hash_alg) );
     if( PSA_SUCCESS != psa_set_key_policy( key, &policy ) )
         return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
 
     /* import private key in slot */
-    key_type = PSA_KEY_TYPE_ECC_KEYPAIR(curve_id);
     if( PSA_SUCCESS != psa_import_key( key, key_type, d, d_len ) )
         return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
 
diff --git a/features/mbedtls/src/pk_wrap.c b/features/mbedtls/src/pk_wrap.c
index 6aacba856d..c7f879ab5a 100644
--- a/features/mbedtls/src/pk_wrap.c
+++ b/features/mbedtls/src/pk_wrap.c
@@ -546,14 +546,14 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *sig, size_t sig_len )
 {
     int ret;
-    psa_key_slot_t key_slot;
+    psa_key_handle_t key_slot;
     psa_key_policy_t policy;
     psa_key_type_t psa_type;
     mbedtls_pk_context key;
     int key_len;
     /* see ECP_PUB_DER_MAX_BYTES in pkwrite.c */
     unsigned char buf[30 + 2 * MBEDTLS_ECP_MAX_BYTES];
-    unsigned char *p = (unsigned char*) sig;
+    unsigned char *p;
     mbedtls_pk_info_t pk_info = mbedtls_eckey_info;
     psa_algorithm_t psa_sig_md, psa_md;
     psa_ecc_curve_t curve = mbedtls_psa_translate_ecc_group(
@@ -563,24 +563,25 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
     if( curve == 0 )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
-    /* mbedlts_pk_write_pubkey_der() expects a full PK context,
+    /* mbedtls_pk_write_pubkey() expects a full PK context;
      * re-construct one to make it happy */
     key.pk_info = &pk_info;
     key.pk_ctx = ctx;
-    key_len = mbedtls_pk_write_pubkey_der( &key, buf, sizeof( buf ) );
+    p = buf + sizeof( buf );
+    key_len = mbedtls_pk_write_pubkey( &p, buf, &key );
     if( key_len <= 0 )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
-    if( ( ret = mbedtls_psa_get_free_key_slot( &key_slot ) ) != PSA_SUCCESS )
-        return( mbedtls_psa_err_translate_pk( ret ) );
-
     psa_md = mbedtls_psa_translate_md( md_alg );
     if( psa_md == 0 )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
     psa_sig_md = PSA_ALG_ECDSA( psa_md );
     psa_type = PSA_KEY_TYPE_ECC_PUBLIC_KEY( curve );
 
-    psa_key_policy_init( &policy );
+    if( ( ret = psa_allocate_key( &key_slot ) ) != PSA_SUCCESS )
+          return( mbedtls_psa_err_translate_pk( ret ) );
+
+    policy = psa_key_policy_init();
     psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_VERIFY, psa_sig_md );
     if( ( ret = psa_set_key_policy( key_slot, &policy ) ) != PSA_SUCCESS )
     {
@@ -603,6 +604,7 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
         goto cleanup;
     }
 
+    p = (unsigned char*) sig;
     if( ( ret = extract_ecdsa_sig( &p, sig + sig_len, buf,
                                    signature_part_size ) ) != 0 )
     {
@@ -879,7 +881,7 @@ const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
 
 static void *pk_opaque_alloc_wrap( void )
 {
-    void *ctx = mbedtls_calloc( 1, sizeof( psa_key_slot_t ) );
+    void *ctx = mbedtls_calloc( 1, sizeof( psa_key_handle_t ) );
 
     /* no _init() function to call, an calloc() already zeroized */
 
@@ -888,13 +890,13 @@ static void *pk_opaque_alloc_wrap( void )
 
 static void pk_opaque_free_wrap( void *ctx )
 {
-    mbedtls_platform_zeroize( ctx, sizeof( psa_key_slot_t ) );
+    mbedtls_platform_zeroize( ctx, sizeof( psa_key_handle_t ) );
     mbedtls_free( ctx );
 }
 
 static size_t pk_opaque_get_bitlen( const void *ctx )
 {
-    const psa_key_slot_t *key = (const psa_key_slot_t *) ctx;
+    const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
     size_t bits;
 
     if( PSA_SUCCESS != psa_get_key_information( *key, NULL, &bits ) )
@@ -999,7 +1001,7 @@ static int pk_opaque_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
-    const psa_key_slot_t *key = (const psa_key_slot_t *) ctx;
+    const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
     psa_algorithm_t alg = PSA_ALG_ECDSA( mbedtls_psa_translate_md( md_alg ) );
     size_t bits, buf_len;
     psa_status_t status;
diff --git a/features/mbedtls/src/pkcs12.c b/features/mbedtls/src/pkcs12.c
index 16a15cb63e..7edf064c13 100644
--- a/features/mbedtls/src/pkcs12.c
+++ b/features/mbedtls/src/pkcs12.c
@@ -48,6 +48,8 @@
 #include "mbedtls/des.h"
 #endif
 
+#if defined(MBEDTLS_ASN1_PARSE_C)
+
 static int pkcs12_parse_pbe_params( mbedtls_asn1_buf *params,
                                     mbedtls_asn1_buf *salt, int *iterations )
 {
@@ -226,6 +228,8 @@ exit:
     return( ret );
 }
 
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
                                 const unsigned char *filler, size_t fill_len )
 {
diff --git a/features/mbedtls/src/pkcs5.c b/features/mbedtls/src/pkcs5.c
index f04f0ab25e..50133435ce 100644
--- a/features/mbedtls/src/pkcs5.c
+++ b/features/mbedtls/src/pkcs5.c
@@ -54,22 +54,7 @@
 #define mbedtls_printf printf
 #endif
 
-#if !defined(MBEDTLS_ASN1_PARSE_C)
-int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode,
-                 const unsigned char *pwd,  size_t pwdlen,
-                 const unsigned char *data, size_t datalen,
-                 unsigned char *output )
-{
-    ((void) pbe_params);
-    ((void) mode);
-    ((void) pwd);
-    ((void) pwdlen);
-    ((void) data);
-    ((void) datalen);
-    ((void) output);
-    return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
-}
-#else
+#if defined(MBEDTLS_ASN1_PARSE_C)
 static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params,
                                       mbedtls_asn1_buf *salt, int *iterations,
                                       int *keylen, mbedtls_md_type_t *md_type )
diff --git a/features/mbedtls/src/pkparse.c b/features/mbedtls/src/pkparse.c
index 86d9fb004f..ae210bca6a 100644
--- a/features/mbedtls/src/pkparse.c
+++ b/features/mbedtls/src/pkparse.c
@@ -61,6 +61,12 @@
 #define mbedtls_free       free
 #endif
 
+/* Parameter validation macros based on platform_util.h */
+#define PK_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
+#define PK_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_FS_IO)
 /*
  * Load all data from a file into a given buffer.
@@ -74,6 +80,10 @@ int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n )
     FILE *f;
     long size;
 
+    PK_VALIDATE_RET( path != NULL );
+    PK_VALIDATE_RET( buf != NULL );
+    PK_VALIDATE_RET( n != NULL );
+
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
 
@@ -124,6 +134,9 @@ int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
     size_t n;
     unsigned char *buf;
 
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( path != NULL );
+
     if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
         return( ret );
 
@@ -148,6 +161,9 @@ int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path )
     size_t n;
     unsigned char *buf;
 
+    PK_VALIDATE_RET( ctx != NULL );
+    PK_VALIDATE_RET( path != NULL );
+
     if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
         return( ret );
 
@@ -605,6 +621,11 @@ int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
     mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
     const mbedtls_pk_info_t *pk_info;
 
+    PK_VALIDATE_RET( p != NULL );
+    PK_VALIDATE_RET( *p != NULL );
+    PK_VALIDATE_RET( end != NULL );
+    PK_VALIDATE_RET( pk != NULL );
+
     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
                     MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
     {
@@ -1145,16 +1166,22 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
 {
     int ret;
     const mbedtls_pk_info_t *pk_info;
-
 #if defined(MBEDTLS_PEM_PARSE_C)
     size_t len;
     mbedtls_pem_context pem;
+#endif
 
-    mbedtls_pem_init( &pem );
+    PK_VALIDATE_RET( pk != NULL );
+    if( keylen == 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+    PK_VALIDATE_RET( key != NULL );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+   mbedtls_pem_init( &pem );
 
 #if defined(MBEDTLS_RSA_C)
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
@@ -1185,7 +1212,7 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
 
 #if defined(MBEDTLS_ECP_C)
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
@@ -1215,7 +1242,7 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
 #endif /* MBEDTLS_ECP_C */
 
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
@@ -1238,7 +1265,7 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
 
 #if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
@@ -1276,9 +1303,6 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
     {
         unsigned char *key_copy;
 
-        if( keylen == 0 )
-            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
-
         if( ( key_copy = mbedtls_calloc( 1, keylen ) ) == NULL )
             return( MBEDTLS_ERR_PK_ALLOC_FAILED );
 
@@ -1360,11 +1384,18 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
 #if defined(MBEDTLS_PEM_PARSE_C)
     size_t len;
     mbedtls_pem_context pem;
+#endif
 
+    PK_VALIDATE_RET( ctx != NULL );
+    if( keylen == 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+    PK_VALIDATE_RET( key != NULL || keylen == 0 );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_init( &pem );
 #if defined(MBEDTLS_RSA_C)
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
@@ -1395,7 +1426,7 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
 #endif /* MBEDTLS_RSA_C */
 
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( keylen == 0 || key[keylen - 1] != '\0' )
+    if( key[keylen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
diff --git a/features/mbedtls/src/pkwrite.c b/features/mbedtls/src/pkwrite.c
index d34714b342..b87f81b8b7 100644
--- a/features/mbedtls/src/pkwrite.c
+++ b/features/mbedtls/src/pkwrite.c
@@ -30,6 +30,7 @@
 #include "mbedtls/pk.h"
 #include "mbedtls/asn1write.h"
 #include "mbedtls/oid.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
@@ -48,6 +49,7 @@
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 #include "psa/crypto.h"
+#include "mbedtls/psa_util.h"
 #endif
 #if defined(MBEDTLS_PLATFORM_C)
 #include "mbedtls/platform.h"
@@ -57,6 +59,12 @@
 #define mbedtls_free       free
 #endif
 
+/* Parameter validation macros based on platform_util.h */
+#define PK_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
+#define PK_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_RSA_C)
 /*
  *  RSAPublicKey ::= SEQUENCE {
@@ -154,6 +162,11 @@ int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
     int ret;
     size_t len = 0;
 
+    PK_VALIDATE_RET( p != NULL );
+    PK_VALIDATE_RET( *p != NULL );
+    PK_VALIDATE_RET( start != NULL );
+    PK_VALIDATE_RET( key != NULL );
+
 #if defined(MBEDTLS_RSA_C)
     if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
         MBEDTLS_ASN1_CHK_ADD( len, pk_write_rsa_pubkey( p, start, mbedtls_pk_rsa( *key ) ) );
@@ -168,7 +181,7 @@ int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
     if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_OPAQUE )
     {
         size_t buffer_size;
-        psa_key_slot_t* key_slot = (psa_key_slot_t*) key->pk_ctx;
+        psa_key_handle_t* key_slot = (psa_key_handle_t*) key->pk_ctx;
 
         if ( *p < start )
             return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
@@ -181,7 +194,8 @@ int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
         }
         else
         {
-            memmove( *p - len, start, len );
+            *p -= len;
+            memmove( *p, start, len );
         }
     }
     else
@@ -196,16 +210,18 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, si
     int ret;
     unsigned char *c;
     size_t len = 0, par_len = 0, oid_len;
+    mbedtls_pk_type_t pk_type;
     const char *oid;
 
+    PK_VALIDATE_RET( key != NULL );
+    if( size == 0 )
+        return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+    PK_VALIDATE_RET( buf != NULL );
+
     c = buf + size;
 
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );
 
-    if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_OPAQUE )
-    {
-        return( (int) len );
-    }
     if( c - buf < 1 )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
@@ -220,18 +236,51 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, si
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
 
-    if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
-                                       &oid, &oid_len ) ) != 0 )
-    {
-        return( ret );
-    }
-
+    pk_type = mbedtls_pk_get_type( key );
 #if defined(MBEDTLS_ECP_C)
-    if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
+    if( pk_type == MBEDTLS_PK_ECKEY )
     {
         MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
     }
 #endif
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    if( pk_type == MBEDTLS_PK_OPAQUE )
+    {
+        psa_status_t status;
+        psa_key_type_t key_type;
+        psa_key_handle_t handle;
+        psa_ecc_curve_t curve;
+
+        handle = *((psa_key_handle_t*) key->pk_ctx );
+
+        status = psa_get_key_information( handle, &key_type,
+                                          NULL /* bitsize not needed */ );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
+
+        curve = PSA_KEY_TYPE_GET_CURVE( key_type );
+        if( curve == 0 )
+            return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+        ret = mbedtls_psa_get_ecc_oid_from_id( curve, &oid, &oid_len );
+        if( ret != 0 )
+            return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+        /* Write EC algorithm parameters; that's akin
+         * to pk_write_ec_param() above. */
+        MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_oid( &c, buf,
+                                                               oid, oid_len ) );
+
+        /* The rest of the function works as for legacy EC contexts. */
+        pk_type = MBEDTLS_PK_ECKEY;
+    }
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
+    if( ( ret = mbedtls_oid_get_oid_by_pk_alg( pk_type, &oid,
+                                               &oid_len ) ) != 0 )
+    {
+        return( ret );
+    }
 
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
                                                         par_len ) );
@@ -246,9 +295,16 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, si
 int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
 {
     int ret;
-    unsigned char *c = buf + size;
+    unsigned char *c;
     size_t len = 0;
 
+    PK_VALIDATE_RET( key != NULL );
+    if( size == 0 )
+        return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+    PK_VALIDATE_RET( buf != NULL );
+
+    c = buf + size;
+
 #if defined(MBEDTLS_RSA_C)
     if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
     {
@@ -486,6 +542,9 @@ int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, si
     unsigned char output_buf[PUB_DER_MAX_BYTES];
     size_t olen = 0;
 
+    PK_VALIDATE_RET( key != NULL );
+    PK_VALIDATE_RET( buf != NULL || size == 0 );
+
     if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
                                      sizeof(output_buf) ) ) < 0 )
     {
@@ -509,6 +568,9 @@ int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_
     const char *begin, *end;
     size_t olen = 0;
 
+    PK_VALIDATE_RET( key != NULL );
+    PK_VALIDATE_RET( buf != NULL || size == 0 );
+
     if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
         return( ret );
 
diff --git a/features/mbedtls/src/platform.c b/features/mbedtls/src/platform.c
index 73a6db9ebe..5756159543 100644
--- a/features/mbedtls/src/platform.c
+++ b/features/mbedtls/src/platform.c
@@ -82,28 +82,15 @@ int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
           !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&
              defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */
 
-#if defined(_WIN32)
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_SNPRINTF)
 #include <stdarg.h>
 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... )
 {
     int ret;
     va_list argp;
 
-    /* Avoid calling the invalid parameter handler by checking ourselves */
-    if( s == NULL || n == 0 || fmt == NULL )
-        return( -1 );
-
     va_start( argp, fmt );
-#if defined(_TRUNCATE) && !defined(__MINGW32__)
-    ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp );
-#else
-    ret = _vsnprintf( s, n, fmt, argp );
-    if( ret < 0 || (size_t) ret == n )
-    {
-        s[n-1] = '\0';
-        ret = -1;
-    }
-#endif
+    ret = mbedtls_vsnprintf( s, n, fmt, argp );
     va_end( argp );
 
     return( ret );
@@ -140,6 +127,62 @@ int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
 }
 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
 
+#if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_VSNPRINTF)
+#include <stdarg.h>
+int mbedtls_platform_win32_vsnprintf( char *s, size_t n, const char *fmt, va_list arg )
+{
+    int ret;
+
+    /* Avoid calling the invalid parameter handler by checking ourselves */
+    if( s == NULL || n == 0 || fmt == NULL )
+        return( -1 );
+
+#if defined(_TRUNCATE)
+    ret = vsnprintf_s( s, n, _TRUNCATE, fmt, arg );
+#else
+    ret = vsnprintf( s, n, fmt, arg );
+    if( ret < 0 || (size_t) ret == n )
+    {
+        s[n-1] = '\0';
+        ret = -1;
+    }
+#endif
+
+    return( ret );
+}
+#endif
+
+#if defined(MBEDTLS_PLATFORM_VSNPRINTF_ALT)
+#if !defined(MBEDTLS_PLATFORM_STD_VSNPRINTF)
+/*
+ * Make dummy function to prevent NULL pointer dereferences
+ */
+static int platform_vsnprintf_uninit( char * s, size_t n,
+                                     const char * format, va_list arg )
+{
+    ((void) s);
+    ((void) n);
+    ((void) format);
+    ((void) arg);
+    return( -1 );
+}
+
+#define MBEDTLS_PLATFORM_STD_VSNPRINTF    platform_vsnprintf_uninit
+#endif /* !MBEDTLS_PLATFORM_STD_VSNPRINTF */
+
+int (*mbedtls_vsnprintf)( char * s, size_t n,
+                          const char * format,
+                          va_list arg ) = MBEDTLS_PLATFORM_STD_VSNPRINTF;
+
+int mbedtls_platform_set_vsnprintf( int (*vsnprintf_func)( char * s, size_t n,
+                                                 const char * format,
+                                                 va_list arg ) )
+{
+    mbedtls_vsnprintf = vsnprintf_func;
+    return( 0 );
+}
+#endif /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
+
 #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
 /*
diff --git a/features/mbedtls/src/platform_util.c b/features/mbedtls/src/platform_util.c
index ca5fe4fb87..756e22679a 100644
--- a/features/mbedtls/src/platform_util.c
+++ b/features/mbedtls/src/platform_util.c
@@ -35,6 +35,7 @@
 #endif
 
 #include "mbedtls/platform_util.h"
+#include "mbedtls/platform.h"
 #include "mbedtls/threading.h"
 
 #include <stddef.h>
diff --git a/features/mbedtls/src/poly1305.c b/features/mbedtls/src/poly1305.c
index e22d3afb68..b274119181 100644
--- a/features/mbedtls/src/poly1305.c
+++ b/features/mbedtls/src/poly1305.c
@@ -49,6 +49,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define POLY1305_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA )
+#define POLY1305_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define POLY1305_BLOCK_SIZE_BYTES ( 16U )
 
 #define BYTES_TO_U32_LE( data, offset )                           \
@@ -276,27 +282,24 @@ static void poly1305_compute_mac( const mbedtls_poly1305_context *ctx,
 
 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
-    }
+    POLY1305_VALIDATE( ctx != NULL );
+
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
 }
 
 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
-    }
+    if( ctx == NULL )
+        return;
+
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
 }
 
 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx,
                              const unsigned char key[32] )
 {
-    if( ctx == NULL || key == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( key != NULL );
 
     /* r &= 0x0ffffffc0ffffffc0ffffffc0fffffff */
     ctx->r[0] = BYTES_TO_U32_LE( key, 0 )  & 0x0FFFFFFFU;
@@ -331,16 +334,8 @@ int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
     size_t remaining = ilen;
     size_t queue_free_len;
     size_t nblocks;
-
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( ilen > 0U ) && ( input == NULL ) )
-    {
-        /* input pointer is allowed to be NULL only if ilen == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( ilen == 0 || input != NULL );
 
     if( ( remaining > 0U ) && ( ctx->queue_len > 0U ) )
     {
@@ -398,10 +393,8 @@ int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
                              unsigned char mac[16] )
 {
-    if( ( ctx == NULL ) || ( mac == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( mac != NULL );
 
     /* Process any leftover data */
     if( ctx->queue_len > 0U )
@@ -431,6 +424,9 @@ int mbedtls_poly1305_mac( const unsigned char key[32],
 {
     mbedtls_poly1305_context ctx;
     int ret;
+    POLY1305_VALIDATE_RET( key != NULL );
+    POLY1305_VALIDATE_RET( mac != NULL );
+    POLY1305_VALIDATE_RET( ilen == 0 || input != NULL );
 
     mbedtls_poly1305_init( &ctx );
 
diff --git a/features/mbedtls/src/rsa.c b/features/mbedtls/src/rsa.c
index 7615e1e5c3..a35af44746 100644
--- a/features/mbedtls/src/rsa.c
+++ b/features/mbedtls/src/rsa.c
@@ -71,6 +71,12 @@
 
 #if !defined(MBEDTLS_RSA_ALT)
 
+/* Parameter validation macros */
+#define RSA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
+#define RSA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_PKCS1_V15)
 /* constant-time buffer comparison */
 static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
@@ -93,6 +99,7 @@ int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
                         const mbedtls_mpi *D, const mbedtls_mpi *E )
 {
     int ret;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) ||
         ( P != NULL && ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ) ||
@@ -117,6 +124,7 @@ int mbedtls_rsa_import_raw( mbedtls_rsa_context *ctx,
                             unsigned char const *E, size_t E_len )
 {
     int ret = 0;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     if( N != NULL )
     {
@@ -240,12 +248,16 @@ static int rsa_check_context( mbedtls_rsa_context const *ctx, int is_priv,
 int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
 {
     int ret = 0;
+    int have_N, have_P, have_Q, have_D, have_E;
+    int n_missing, pq_missing, d_missing, is_pub, is_priv;
 
-    const int have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
-    const int have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
-    const int have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
-    const int have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
-    const int have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
+    RSA_VALIDATE_RET( ctx != NULL );
+
+    have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
+    have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
+    have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
+    have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
+    have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
 
     /*
      * Check whether provided parameters are enough
@@ -257,13 +269,13 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
      *
      */
 
-    const int n_missing  =              have_P &&  have_Q &&  have_D && have_E;
-    const int pq_missing =   have_N && !have_P && !have_Q &&  have_D && have_E;
-    const int d_missing  =              have_P &&  have_Q && !have_D && have_E;
-    const int is_pub     =   have_N && !have_P && !have_Q && !have_D && have_E;
+    n_missing  =              have_P &&  have_Q &&  have_D && have_E;
+    pq_missing =   have_N && !have_P && !have_Q &&  have_D && have_E;
+    d_missing  =              have_P &&  have_Q && !have_D && have_E;
+    is_pub     =   have_N && !have_P && !have_Q && !have_D && have_E;
 
     /* These three alternatives are mutually exclusive */
-    const int is_priv = n_missing || pq_missing || d_missing;
+    is_priv = n_missing || pq_missing || d_missing;
 
     if( !is_priv && !is_pub )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -336,9 +348,11 @@ int mbedtls_rsa_export_raw( const mbedtls_rsa_context *ctx,
                             unsigned char *E, size_t E_len )
 {
     int ret = 0;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    const int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -379,9 +393,11 @@ int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
                         mbedtls_mpi *D, mbedtls_mpi *E )
 {
     int ret;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -421,9 +437,11 @@ int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
                             mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP )
 {
     int ret;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -459,6 +477,10 @@ void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
                int padding,
                int hash_id )
 {
+    RSA_VALIDATE( ctx != NULL );
+    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+                  padding == MBEDTLS_RSA_PKCS_V21 );
+
     memset( ctx, 0, sizeof( mbedtls_rsa_context ) );
 
     mbedtls_rsa_set_padding( ctx, padding, hash_id );
@@ -471,8 +493,13 @@ void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
 /*
  * Set padding for an existing RSA context
  */
-void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding, int hash_id )
+void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding,
+                              int hash_id )
 {
+    RSA_VALIDATE( ctx != NULL );
+    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+                  padding == MBEDTLS_RSA_PKCS_V21 );
+
     ctx->padding = padding;
     ctx->hash_id = hash_id;
 }
@@ -503,11 +530,10 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
     int ret;
     mbedtls_mpi H, G, L;
     int prime_quality = 0;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( f_rng != NULL );
 
-    if( f_rng == NULL || nbits < 128 || exponent < 3 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    if( nbits % 2 )
+    if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
     /*
@@ -612,6 +638,8 @@ cleanup:
  */
 int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+
     if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) != 0 )
         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
 
@@ -635,6 +663,8 @@ int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
  */
 int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+
     if( mbedtls_rsa_check_pubkey( ctx ) != 0 ||
         rsa_check_context( ctx, 1 /* private */, 1 /* blinding */ ) != 0 )
     {
@@ -664,6 +694,9 @@ int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
 int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub,
                                 const mbedtls_rsa_context *prv )
 {
+    RSA_VALIDATE_RET( pub != NULL );
+    RSA_VALIDATE_RET( prv != NULL );
+
     if( mbedtls_rsa_check_pubkey( pub )  != 0 ||
         mbedtls_rsa_check_privkey( prv ) != 0 )
     {
@@ -689,6 +722,9 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
     int ret;
     size_t olen;
     mbedtls_mpi T;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( output != NULL );
 
     if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -831,6 +867,10 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
      * checked result; should be the same in the end. */
     mbedtls_mpi I, C;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( input  != NULL );
+    RSA_VALIDATE_RET( output != NULL );
+
     if( rsa_check_context( ctx, 1             /* private key checks */,
                                 f_rng != NULL /* blinding y/n       */ ) != 0 )
     {
@@ -1091,6 +1131,13 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
+    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1124,7 +1171,8 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
     p += hlen;
     p += olen - 2 * hlen - 2 - ilen;
     *p++ = 1;
-    memcpy( p, input, ilen );
+    if( ilen != 0 )
+        memcpy( p, input, ilen );
 
     mbedtls_md_init( &md_ctx );
     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
@@ -1167,11 +1215,13 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
     int ret;
     unsigned char *p = output;
 
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
 
-    // We don't check p_rng because it won't be dereferenced here
-    if( f_rng == NULL || input == NULL || output == NULL )
+    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
     olen = ctx->len;
@@ -1185,6 +1235,9 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
     *p++ = 0;
     if( mode == MBEDTLS_RSA_PUBLIC )
     {
+        if( f_rng == NULL )
+            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
         *p++ = MBEDTLS_RSA_CRYPT;
 
         while( nb_pad-- > 0 )
@@ -1211,7 +1264,8 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
     }
 
     *p++ = 0;
-    memcpy( p, input, ilen );
+    if( ilen != 0 )
+        memcpy( p, input, ilen );
 
     return( ( mode == MBEDTLS_RSA_PUBLIC )
             ? mbedtls_rsa_public(  ctx, output, output )
@@ -1229,6 +1283,12 @@ int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
                        const unsigned char *input,
                        unsigned char *output )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1271,6 +1331,14 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
     /*
      * Parameters sanity checks
      */
@@ -1375,7 +1443,8 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
     }
 
     *olen = ilen - (p - buf);
-    memcpy( output, p, *olen );
+    if( *olen != 0 )
+        memcpy( output, p, *olen );
     ret = 0;
 
 cleanup:
@@ -1387,6 +1456,97 @@ cleanup:
 #endif /* MBEDTLS_PKCS1_V21 */
 
 #if defined(MBEDTLS_PKCS1_V15)
+/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
+ *
+ * \param value     The value to analyze.
+ * \return          Zero if \p value is zero, otherwise all-bits-one.
+ */
+static unsigned all_or_nothing_int( unsigned value )
+{
+    /* MSVC has a warning about unary minus on unsigned, but this is
+     * well-defined and precisely what we want to do here */
+#if defined(_MSC_VER)
+#pragma warning( push )
+#pragma warning( disable : 4146 )
+#endif
+    return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
+#if defined(_MSC_VER)
+#pragma warning( pop )
+#endif
+}
+
+/** Check whether a size is out of bounds, without branches.
+ *
+ * This is equivalent to `size > max`, but is likely to be compiled to
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param size      Size to check.
+ * \param max       Maximum desired value for \p size.
+ * \return          \c 0 if `size <= max`.
+ * \return          \c 1 if `size > max`.
+ */
+static unsigned size_greater_than( size_t size, size_t max )
+{
+    /* Return the sign bit (1 for negative) of (max - size). */
+    return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
+}
+
+/** Choose between two integer values, without branches.
+ *
+ * This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param cond      Condition to test.
+ * \param if1       Value to use if \p cond is nonzero.
+ * \param if0       Value to use if \p cond is zero.
+ * \return          \c if1 if \p cond is nonzero, otherwise \c if0.
+ */
+static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
+{
+    unsigned mask = all_or_nothing_int( cond );
+    return( ( mask & if1 ) | (~mask & if0 ) );
+}
+
+/** Shift some data towards the left inside a buffer without leaking
+ * the length of the data through side channels.
+ *
+ * `mem_move_to_left(start, total, offset)` is functionally equivalent to
+ * ```
+ * memmove(start, start + offset, total - offset);
+ * memset(start + offset, 0, total - offset);
+ * ```
+ * but it strives to use a memory access pattern (and thus total timing)
+ * that does not depend on \p offset. This timing independence comes at
+ * the expense of performance.
+ *
+ * \param start     Pointer to the start of the buffer.
+ * \param total     Total size of the buffer.
+ * \param offset    Offset from which to copy \p total - \p offset bytes.
+ */
+static void mem_move_to_left( void *start,
+                              size_t total,
+                              size_t offset )
+{
+    volatile unsigned char *buf = start;
+    size_t i, n;
+    if( total == 0 )
+        return;
+    for( i = 0; i < total; i++ )
+    {
+        unsigned no_op = size_greater_than( total - offset, i );
+        /* The first `total - offset` passes are a no-op. The last
+         * `offset` passes shift the data one byte to the left and
+         * zero out the last byte. */
+        for( n = 0; n < total - 1; n++ )
+        {
+            unsigned char current = buf[n];
+            unsigned char next = buf[n+1];
+            buf[n] = if_int( no_op, current, next );
+        }
+        buf[total-1] = if_int( no_op, buf[total-1], 0 );
+    }
+}
+
 /*
  * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
  */
@@ -1396,18 +1556,42 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
                                  int mode, size_t *olen,
                                  const unsigned char *input,
                                  unsigned char *output,
-                                 size_t output_max_len)
+                                 size_t output_max_len )
 {
     int ret;
-    size_t ilen, pad_count = 0, i;
-    unsigned char *p, bad, pad_done = 0;
+    size_t ilen, i, plaintext_max_size;
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+    /* The following variables take sensitive values: their value must
+     * not leak into the observable behavior of the function other than
+     * the designated outputs (output, olen, return value). Otherwise
+     * this would open the execution of the function to
+     * side-channel-based variants of the Bleichenbacher padding oracle
+     * attack. Potential side channels include overall timing, memory
+     * access patterns (especially visible to an adversary who has access
+     * to a shared memory cache), and branches (especially visible to
+     * an adversary who has access to a shared code cache or to a shared
+     * branch predictor). */
+    size_t pad_count = 0;
+    unsigned bad = 0;
+    unsigned char pad_done = 0;
+    size_t plaintext_size = 0;
+    unsigned output_too_large;
+
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
+    ilen = ctx->len;
+    plaintext_max_size = ( output_max_len > ilen - 11 ?
+                           ilen - 11 :
+                           output_max_len );
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
-    ilen = ctx->len;
-
     if( ilen < 16 || ilen > sizeof( buf ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1418,63 +1602,115 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
     if( ret != 0 )
         goto cleanup;
 
-    p = buf;
-    bad = 0;
+    /* Check and get padding length in constant time and constant
+     * memory trace. The first byte must be 0. */
+    bad |= buf[0];
 
-    /*
-     * Check and get padding len in "constant-time"
-     */
-    bad |= *p++; /* First byte must be 0 */
-
-    /* This test does not depend on secret data */
     if( mode == MBEDTLS_RSA_PRIVATE )
     {
-        bad |= *p++ ^ MBEDTLS_RSA_CRYPT;
+        /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
+         * where PS must be at least 8 nonzero bytes. */
+        bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
 
-        /* Get padding len, but always read till end of buffer
-         * (minus one, for the 00 byte) */
-        for( i = 0; i < ilen - 3; i++ )
+        /* Read the whole buffer. Set pad_done to nonzero if we find
+         * the 0x00 byte and remember the padding length in pad_count. */
+        for( i = 2; i < ilen; i++ )
         {
-            pad_done  |= ((p[i] | (unsigned char)-p[i]) >> 7) ^ 1;
+            pad_done  |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
             pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
         }
-
-        p += pad_count;
-        bad |= *p++; /* Must be zero */
     }
     else
     {
-        bad |= *p++ ^ MBEDTLS_RSA_SIGN;
+        /* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
+         * where PS must be at least 8 bytes with the value 0xFF. */
+        bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
 
-        /* Get padding len, but always read till end of buffer
-         * (minus one, for the 00 byte) */
-        for( i = 0; i < ilen - 3; i++ )
+        /* Read the whole buffer. Set pad_done to nonzero if we find
+         * the 0x00 byte and remember the padding length in pad_count.
+         * If there's a non-0xff byte in the padding, the padding is bad. */
+        for( i = 2; i < ilen; i++ )
         {
-            pad_done |= ( p[i] != 0xFF );
-            pad_count += ( pad_done == 0 );
+            pad_done |= if_int( buf[i], 0, 1 );
+            pad_count += if_int( pad_done, 0, 1 );
+            bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
         }
-
-        p += pad_count;
-        bad |= *p++; /* Must be zero */
     }
 
-    bad |= ( pad_count < 8 );
+    /* If pad_done is still zero, there's no data, only unfinished padding. */
+    bad |= if_int( pad_done, 0, 1 );
 
-    if( bad )
-    {
-        ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
-        goto cleanup;
-    }
+    /* There must be at least 8 bytes of padding. */
+    bad |= size_greater_than( 8, pad_count );
 
-    if( ilen - ( p - buf ) > output_max_len )
-    {
-        ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
-        goto cleanup;
-    }
+    /* If the padding is valid, set plaintext_size to the number of
+     * remaining bytes after stripping the padding. If the padding
+     * is invalid, avoid leaking this fact through the size of the
+     * output: use the maximum message size that fits in the output
+     * buffer. Do it without branches to avoid leaking the padding
+     * validity through timing. RSA keys are small enough that all the
+     * size_t values involved fit in unsigned int. */
+    plaintext_size = if_int( bad,
+                             (unsigned) plaintext_max_size,
+                             (unsigned) ( ilen - pad_count - 3 ) );
 
-    *olen = ilen - (p - buf);
-    memcpy( output, p, *olen );
-    ret = 0;
+    /* Set output_too_large to 0 if the plaintext fits in the output
+     * buffer and to 1 otherwise. */
+    output_too_large = size_greater_than( plaintext_size,
+                                          plaintext_max_size );
+
+    /* Set ret without branches to avoid timing attacks. Return:
+     * - INVALID_PADDING if the padding is bad (bad != 0).
+     * - OUTPUT_TOO_LARGE if the padding is good but the decrypted
+     *   plaintext does not fit in the output buffer.
+     * - 0 if the padding is correct. */
+    ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
+                  if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
+                          0 ) );
+
+    /* If the padding is bad or the plaintext is too large, zero the
+     * data that we're about to copy to the output buffer.
+     * We need to copy the same amount of data
+     * from the same buffer whether the padding is good or not to
+     * avoid leaking the padding validity through overall timing or
+     * through memory or cache access patterns. */
+    bad = all_or_nothing_int( bad | output_too_large );
+    for( i = 11; i < ilen; i++ )
+        buf[i] &= ~bad;
+
+    /* If the plaintext is too large, truncate it to the buffer size.
+     * Copy anyway to avoid revealing the length through timing, because
+     * revealing the length is as bad as revealing the padding validity
+     * for a Bleichenbacher attack. */
+    plaintext_size = if_int( output_too_large,
+                             (unsigned) plaintext_max_size,
+                             (unsigned) plaintext_size );
+
+    /* Move the plaintext to the leftmost position where it can start in
+     * the working buffer, i.e. make it start plaintext_max_size from
+     * the end of the buffer. Do this with a memory access trace that
+     * does not depend on the plaintext size. After this move, the
+     * starting location of the plaintext is no longer sensitive
+     * information. */
+    mem_move_to_left( buf + ilen - plaintext_max_size,
+                      plaintext_max_size,
+                      plaintext_max_size - plaintext_size );
+
+    /* Finally copy the decrypted plaintext plus trailing zeros into the output
+     * buffer. If output_max_len is 0, then output may be an invalid pointer
+     * and the result of memcpy() would be undefined; prevent undefined
+     * behavior making sure to depend only on output_max_len (the size of the
+     * user-provided output buffer), which is independent from plaintext
+     * length, validity of padding, success of the decryption, and other
+     * secrets. */
+    if( output_max_len != 0 )
+        memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
+
+    /* Report the amount of data we copied to the output buffer. In case
+     * of errors (bad padding or output too large), the value of *olen
+     * when this function returns is not specified. Making it equivalent
+     * to the good case limits the risks of leaking the padding validity. */
+    *olen = plaintext_size;
 
 cleanup:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
@@ -1494,6 +1730,13 @@ int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
                        unsigned char *output,
                        size_t output_max_len)
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1535,6 +1778,13 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
     size_t msb;
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -1782,6 +2032,14 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
     int ret;
     unsigned char *sig_try = NULL, *verif = NULL;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1851,6 +2109,14 @@ int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
                     const unsigned char *hash,
                     unsigned char *sig )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1897,6 +2163,14 @@ int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
     mbedtls_md_context_t md_ctx;
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -2025,7 +2299,16 @@ int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx,
                            const unsigned char *hash,
                            const unsigned char *sig )
 {
-    mbedtls_md_type_t mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
+    mbedtls_md_type_t mgf1_hash_id;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
+    mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
                              ? (mbedtls_md_type_t) ctx->hash_id
                              : md_alg;
 
@@ -2051,9 +2334,19 @@ int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
                                  const unsigned char *sig )
 {
     int ret = 0;
-    const size_t sig_len = ctx->len;
+    size_t sig_len;
     unsigned char *encoded = NULL, *encoded_expected = NULL;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
+    sig_len = ctx->len;
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -2123,6 +2416,14 @@ int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
                       const unsigned char *hash,
                       const unsigned char *sig )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -2148,6 +2449,8 @@ int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
 int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
 {
     int ret;
+    RSA_VALIDATE_RET( dst != NULL );
+    RSA_VALIDATE_RET( src != NULL );
 
     dst->ver = src->ver;
     dst->len = src->len;
@@ -2187,14 +2490,23 @@ cleanup:
  */
 void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
 {
-    mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->Vf );
-    mbedtls_mpi_free( &ctx->RN ); mbedtls_mpi_free( &ctx->D  );
-    mbedtls_mpi_free( &ctx->Q  ); mbedtls_mpi_free( &ctx->P  );
-    mbedtls_mpi_free( &ctx->E  ); mbedtls_mpi_free( &ctx->N  );
+    if( ctx == NULL )
+        return;
+
+    mbedtls_mpi_free( &ctx->Vi );
+    mbedtls_mpi_free( &ctx->Vf );
+    mbedtls_mpi_free( &ctx->RN );
+    mbedtls_mpi_free( &ctx->D  );
+    mbedtls_mpi_free( &ctx->Q  );
+    mbedtls_mpi_free( &ctx->P  );
+    mbedtls_mpi_free( &ctx->E  );
+    mbedtls_mpi_free( &ctx->N  );
 
 #if !defined(MBEDTLS_RSA_NO_CRT)
-    mbedtls_mpi_free( &ctx->RQ ); mbedtls_mpi_free( &ctx->RP );
-    mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ );
+    mbedtls_mpi_free( &ctx->RQ );
+    mbedtls_mpi_free( &ctx->RP );
+    mbedtls_mpi_free( &ctx->QP );
+    mbedtls_mpi_free( &ctx->DQ );
     mbedtls_mpi_free( &ctx->DP );
 #endif /* MBEDTLS_RSA_NO_CRT */
 
diff --git a/features/mbedtls/src/sha1.c b/features/mbedtls/src/sha1.c
index bab6087c4e..e8d4096fbb 100644
--- a/features/mbedtls/src/sha1.c
+++ b/features/mbedtls/src/sha1.c
@@ -46,6 +46,11 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA1_VALIDATE_RET(cond)                             \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA1_BAD_INPUT_DATA )
+
+#define SHA1_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA1_ALT)
 
 /*
@@ -73,6 +78,8 @@
 
 void mbedtls_sha1_init( mbedtls_sha1_context *ctx )
 {
+    SHA1_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha1_context ) );
 }
 
@@ -87,6 +94,9 @@ void mbedtls_sha1_free( mbedtls_sha1_context *ctx )
 void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
                          const mbedtls_sha1_context *src )
 {
+    SHA1_VALIDATE( dst != NULL );
+    SHA1_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -95,6 +105,8 @@ void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
  */
 int mbedtls_sha1_starts_ret( mbedtls_sha1_context *ctx )
 {
+    SHA1_VALIDATE_RET( ctx != NULL );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -120,6 +132,9 @@ int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
 {
     uint32_t temp, W[16], A, B, C, D, E;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( (const unsigned char *)data != NULL );
+
     GET_UINT32_BE( W[ 0], data,  0 );
     GET_UINT32_BE( W[ 1], data,  4 );
     GET_UINT32_BE( W[ 2], data,  8 );
@@ -294,6 +309,9 @@ int mbedtls_sha1_update_ret( mbedtls_sha1_context *ctx,
     size_t fill;
     uint32_t left;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -352,6 +370,9 @@ int mbedtls_sha1_finish_ret( mbedtls_sha1_context *ctx,
     uint32_t used;
     uint32_t high, low;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
      */
@@ -420,6 +441,9 @@ int mbedtls_sha1_ret( const unsigned char *input,
     int ret;
     mbedtls_sha1_context ctx;
 
+    SHA1_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA1_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha1_init( &ctx );
 
     if( ( ret = mbedtls_sha1_starts_ret( &ctx ) ) != 0 )
diff --git a/features/mbedtls/src/sha256.c b/features/mbedtls/src/sha256.c
index dbb4a89861..8a540adfbe 100644
--- a/features/mbedtls/src/sha256.c
+++ b/features/mbedtls/src/sha256.c
@@ -49,6 +49,10 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA256_VALIDATE_RET(cond)                           \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA )
+#define SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA256_ALT)
 
 /*
@@ -76,6 +80,8 @@ do {                                                    \
 
 void mbedtls_sha256_init( mbedtls_sha256_context *ctx )
 {
+    SHA256_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha256_context ) );
 }
 
@@ -90,6 +96,9 @@ void mbedtls_sha256_free( mbedtls_sha256_context *ctx )
 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src )
 {
+    SHA256_VALIDATE( dst != NULL );
+    SHA256_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -98,6 +107,9 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
  */
 int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
 {
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -192,6 +204,9 @@ int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
     uint32_t A[8];
     unsigned int i;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
+
     for( i = 0; i < 8; i++ )
         A[i] = ctx->state[i];
 
@@ -263,6 +278,9 @@ int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
     size_t fill;
     uint32_t left;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -321,6 +339,9 @@ int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
     uint32_t used;
     uint32_t high, low;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
      */
@@ -395,6 +416,10 @@ int mbedtls_sha256_ret( const unsigned char *input,
     int ret;
     mbedtls_sha256_context ctx;
 
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha256_init( &ctx );
 
     if( ( ret = mbedtls_sha256_starts_ret( &ctx, is224 ) ) != 0 )
diff --git a/features/mbedtls/src/sha512.c b/features/mbedtls/src/sha512.c
index a9440e8af5..941ecda762 100644
--- a/features/mbedtls/src/sha512.c
+++ b/features/mbedtls/src/sha512.c
@@ -55,6 +55,10 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA512_VALIDATE_RET(cond)                           \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA512_BAD_INPUT_DATA )
+#define SHA512_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA512_ALT)
 
 /*
@@ -90,6 +94,8 @@
 
 void mbedtls_sha512_init( mbedtls_sha512_context *ctx )
 {
+    SHA512_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha512_context ) );
 }
 
@@ -104,6 +110,9 @@ void mbedtls_sha512_free( mbedtls_sha512_context *ctx )
 void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                            const mbedtls_sha512_context *src )
 {
+    SHA512_VALIDATE( dst != NULL );
+    SHA512_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -112,6 +121,9 @@ void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
  */
 int mbedtls_sha512_starts_ret( mbedtls_sha512_context *ctx, int is384 )
 {
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( is384 == 0 || is384 == 1 );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -209,6 +221,9 @@ int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx,
     uint64_t temp1, temp2, W[80];
     uint64_t A, B, C, D, E, F, G, H;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( (const unsigned char *)data != NULL );
+
 #define  SHR(x,n) (x >> n)
 #define ROTR(x,n) (SHR(x,n) | (x << (64 - n)))
 
@@ -294,6 +309,9 @@ int mbedtls_sha512_update_ret( mbedtls_sha512_context *ctx,
     size_t fill;
     unsigned int left;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -351,6 +369,9 @@ int mbedtls_sha512_finish_ret( mbedtls_sha512_context *ctx,
     unsigned used;
     uint64_t high, low;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 16 bytes remain for the length
      */
@@ -427,6 +448,10 @@ int mbedtls_sha512_ret( const unsigned char *input,
     int ret;
     mbedtls_sha512_context ctx;
 
+    SHA512_VALIDATE_RET( is384 == 0 || is384 == 1 );
+    SHA512_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA512_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha512_init( &ctx );
 
     if( ( ret = mbedtls_sha512_starts_ret( &ctx, is384 ) ) != 0 )
diff --git a/features/mbedtls/src/ssl_cache.c b/features/mbedtls/src/ssl_cache.c
index 47867f132d..62a0a29879 100644
--- a/features/mbedtls/src/ssl_cache.c
+++ b/features/mbedtls/src/ssl_cache.c
@@ -40,6 +40,7 @@
 #endif
 
 #include "mbedtls/ssl_cache.h"
+#include "mbedtls/ssl_internal.h"
 
 #include <string.h>
 
@@ -92,16 +93,24 @@ int mbedtls_ssl_cache_get( void *data, mbedtls_ssl_session *session )
                     entry->session.id_len ) != 0 )
             continue;
 
-        memcpy( session->master, entry->session.master, 48 );
+        ret = mbedtls_ssl_session_copy( session, &entry->session );
+        if( ret != 0 )
+        {
+            ret = 1;
+            goto exit;
+        }
 
-        session->verify_result = entry->session.verify_result;
-
-#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
         /*
          * Restore peer certificate (without rest of the original chain)
          */
         if( entry->peer_cert.p != NULL )
         {
+            /* `session->peer_cert` is NULL after the call to
+             * mbedtls_ssl_session_copy(), because cache entries
+             * have the `peer_cert` field set to NULL. */
+
             if( ( session->peer_cert = mbedtls_calloc( 1,
                                  sizeof(mbedtls_x509_crt) ) ) == NULL )
             {
@@ -119,7 +128,7 @@ int mbedtls_ssl_cache_get( void *data, mbedtls_ssl_session *session )
                 goto exit;
             }
         }
-#endif /* MBEDTLS_X509_CRT_PARSE_C */
+#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
         ret = 0;
         goto exit;
@@ -239,9 +248,8 @@ int mbedtls_ssl_cache_set( void *data, const mbedtls_ssl_session *session )
 #endif
     }
 
-    memcpy( &cur->session, session, sizeof( mbedtls_ssl_session ) );
-
-#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     /*
      * If we're reusing an entry, free its certificate first
      */
@@ -250,26 +258,43 @@ int mbedtls_ssl_cache_set( void *data, const mbedtls_ssl_session *session )
         mbedtls_free( cur->peer_cert.p );
         memset( &cur->peer_cert, 0, sizeof(mbedtls_x509_buf) );
     }
+#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
-    /*
-     * Store peer certificate
-     */
-    if( session->peer_cert != NULL )
+    /* Copy the entire session; this temporarily makes a copy of the
+     * X.509 CRT structure even though we only want to store the raw CRT.
+     * This inefficiency will go away as soon as we implement on-demand
+     * parsing of CRTs, in which case there's no need for the `peer_cert`
+     * field anymore in the first place, and we're done after this call. */
+    ret = mbedtls_ssl_session_copy( &cur->session, session );
+    if( ret != 0 )
     {
-        cur->peer_cert.p = mbedtls_calloc( 1, session->peer_cert->raw.len );
+        ret = 1;
+        goto exit;
+    }
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    /* If present, free the X.509 structure and only store the raw CRT data. */
+    if( cur->session.peer_cert != NULL )
+    {
+        cur->peer_cert.p =
+            mbedtls_calloc( 1, cur->session.peer_cert->raw.len );
         if( cur->peer_cert.p == NULL )
         {
             ret = 1;
             goto exit;
         }
 
-        memcpy( cur->peer_cert.p, session->peer_cert->raw.p,
-                session->peer_cert->raw.len );
+        memcpy( cur->peer_cert.p,
+                cur->session.peer_cert->raw.p,
+                cur->session.peer_cert->raw.len );
         cur->peer_cert.len = session->peer_cert->raw.len;
 
+        mbedtls_x509_crt_free( cur->session.peer_cert );
+        mbedtls_free( cur->session.peer_cert );
         cur->session.peer_cert = NULL;
     }
-#endif /* MBEDTLS_X509_CRT_PARSE_C */
+#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
     ret = 0;
 
@@ -311,9 +336,10 @@ void mbedtls_ssl_cache_free( mbedtls_ssl_cache_context *cache )
 
         mbedtls_ssl_session_free( &prv->session );
 
-#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
         mbedtls_free( prv->peer_cert.p );
-#endif /* MBEDTLS_X509_CRT_PARSE_C */
+#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
         mbedtls_free( prv );
     }
diff --git a/features/mbedtls/src/ssl_ciphersuites.c b/features/mbedtls/src/ssl_ciphersuites.c
index 745474effe..518f7dde00 100644
--- a/features/mbedtls/src/ssl_ciphersuites.c
+++ b/features/mbedtls/src/ssl_ciphersuites.c
@@ -43,11 +43,11 @@
 /*
  * Ordered from most preferred to least preferred in terms of security.
  *
- * Current rule (except rc4, weak and null which come last):
+ * Current rule (except RC4 and 3DES, weak and null which come last):
  * 1. By key exchange:
  *    Forward-secure non-PSK > forward-secure PSK > ECJPAKE > other non-PSK > other PSK
  * 2. By key length and cipher:
- *    ChaCha > AES-256 > Camellia-256 > ARIA-256 > AES-128 > Camellia-128 > ARIA-128 > 3DES
+ *    ChaCha > AES-256 > Camellia-256 > ARIA-256 > AES-128 > Camellia-128 > ARIA-128
  * 3. By cipher mode when relevant GCM > CCM > CBC > CCM_8
  * 4. By hash function used when relevant
  * 5. By key exchange/auth again: EC > non-EC
@@ -126,11 +126,6 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256,
     MBEDTLS_TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256,
 
-    /* All remaining >= 128-bit ephemeral suites */
-    MBEDTLS_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
-    MBEDTLS_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
-    MBEDTLS_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA,
-
     /* The PSK ephemeral suites */
     MBEDTLS_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
@@ -162,9 +157,6 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256,
     MBEDTLS_TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256,
 
-    MBEDTLS_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA,
-    MBEDTLS_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA,
-
     /* The ECJPAKE suite */
     MBEDTLS_TLS_ECJPAKE_WITH_AES_128_CCM_8,
 
@@ -228,11 +220,6 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256,
     MBEDTLS_TLS_RSA_WITH_ARIA_128_CBC_SHA256,
 
-    /* All remaining >= 128-bit suites */
-    MBEDTLS_TLS_RSA_WITH_3DES_EDE_CBC_SHA,
-    MBEDTLS_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
-    MBEDTLS_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
-
     /* The RSA PSK suites */
     MBEDTLS_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384,
@@ -251,8 +238,6 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256,
     MBEDTLS_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256,
 
-    MBEDTLS_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA,
-
     /* The PSK suites */
     MBEDTLS_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_PSK_WITH_AES_256_GCM_SHA384,
@@ -275,6 +260,16 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_PSK_WITH_ARIA_128_GCM_SHA256,
     MBEDTLS_TLS_PSK_WITH_ARIA_128_CBC_SHA256,
 
+    /* 3DES suites */
+    MBEDTLS_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
+    MBEDTLS_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA,
     MBEDTLS_TLS_PSK_WITH_3DES_EDE_CBC_SHA,
 
     /* RC4 suites */
@@ -2187,6 +2182,26 @@ const int *mbedtls_ssl_list_ciphersuites( void )
 static int supported_ciphersuites[MAX_CIPHERSUITES];
 static int supported_init = 0;
 
+static int ciphersuite_is_removed( const mbedtls_ssl_ciphersuite_t *cs_info )
+{
+    (void)cs_info;
+
+#if defined(MBEDTLS_REMOVE_ARC4_CIPHERSUITES)
+    if( cs_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
+        return( 1 );
+#endif /* MBEDTLS_REMOVE_ARC4_CIPHERSUITES */
+
+#if defined(MBEDTLS_REMOVE_3DES_CIPHERSUITES)
+    if( cs_info->cipher == MBEDTLS_CIPHER_DES_EDE3_ECB ||
+        cs_info->cipher == MBEDTLS_CIPHER_DES_EDE3_CBC )
+    {
+        return( 1 );
+    }
+#endif /* MBEDTLS_REMOVE_3DES_CIPHERSUITES */
+
+    return( 0 );
+}
+
 const int *mbedtls_ssl_list_ciphersuites( void )
 {
     /*
@@ -2202,14 +2217,12 @@ const int *mbedtls_ssl_list_ciphersuites( void )
              *p != 0 && q < supported_ciphersuites + MAX_CIPHERSUITES - 1;
              p++ )
         {
-#if defined(MBEDTLS_REMOVE_ARC4_CIPHERSUITES)
             const mbedtls_ssl_ciphersuite_t *cs_info;
             if( ( cs_info = mbedtls_ssl_ciphersuite_from_id( *p ) ) != NULL &&
-                cs_info->cipher != MBEDTLS_CIPHER_ARC4_128 )
-#else
-            if( mbedtls_ssl_ciphersuite_from_id( *p ) != NULL )
-#endif
+                !ciphersuite_is_removed( cs_info ) )
+            {
                 *(q++) = *p;
+            }
         }
         *q = 0;
 
diff --git a/features/mbedtls/src/ssl_cli.c b/features/mbedtls/src/ssl_cli.c
index cd25dca91d..4e5b3a6024 100644
--- a/features/mbedtls/src/ssl_cli.c
+++ b/features/mbedtls/src/ssl_cli.c
@@ -39,6 +39,10 @@
 #include "mbedtls/ssl.h"
 #include "mbedtls/ssl_internal.h"
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "mbedtls/psa_util.h"
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 #include <string.h>
 
 #include <stdint.h>
@@ -2074,8 +2078,14 @@ static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl, unsigned char *
 static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
 {
     const mbedtls_ecp_curve_info *curve_info;
+    mbedtls_ecp_group_id grp_id;
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+    grp_id = ssl->handshake->ecdh_ctx.grp.id;
+#else
+    grp_id = ssl->handshake->ecdh_ctx.grp_id;
+#endif
 
-    curve_info = mbedtls_ecp_curve_info_from_grp_id( ssl->handshake->ecdh_ctx.grp.id );
+    curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
     if( curve_info == NULL )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
@@ -2085,14 +2095,15 @@ static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
 
 #if defined(MBEDTLS_ECP_C)
-    if( mbedtls_ssl_check_curve( ssl, ssl->handshake->ecdh_ctx.grp.id ) != 0 )
+    if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
 #else
     if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
         ssl->handshake->ecdh_ctx.grp.nbits > 521 )
 #endif
         return( -1 );
 
-    MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp );
+    MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                            MBEDTLS_DEBUG_ECDH_QP );
 
     return( 0 );
 }
@@ -2102,6 +2113,64 @@ static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
           MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
           MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO) &&                           \
+        ( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||     \
+          defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) )
+static int ssl_parse_server_ecdh_params_psa( mbedtls_ssl_context *ssl,
+                                             unsigned char **p,
+                                             unsigned char *end )
+{
+    uint16_t tls_id;
+    uint8_t ecpoint_len;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+
+    /*
+     * Parse ECC group
+     */
+
+    if( end - *p < 4 )
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+
+    /* First byte is curve_type; only named_curve is handled */
+    if( *(*p)++ != MBEDTLS_ECP_TLS_NAMED_CURVE )
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+
+    /* Next two bytes are the namedcurve value */
+    tls_id = *(*p)++;
+    tls_id <<= 8;
+    tls_id |= *(*p)++;
+
+    /* Convert EC group to PSA key type. */
+    if( ( handshake->ecdh_psa_curve =
+          mbedtls_psa_parse_tls_ecc_group( tls_id ) ) == 0 )
+    {
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+    }
+
+    /*
+     * Put peer's ECDH public key in the format understood by PSA.
+     */
+
+    ecpoint_len = *(*p)++;
+    if( (size_t)( end - *p ) < ecpoint_len )
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+
+    if( mbedtls_psa_tls_ecpoint_to_psa_ec( handshake->ecdh_psa_curve,
+                                    *p, ecpoint_len,
+                                    handshake->ecdh_psa_peerkey,
+                                    sizeof( handshake->ecdh_psa_peerkey ),
+                                    &handshake->ecdh_psa_peerkey_len ) != 0 )
+    {
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+    }
+
+    *p += ecpoint_len;
+    return( 0 );
+}
+#endif /* MBEDTLS_USE_PSA_CRYPTO &&
+            ( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
+              MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
+
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) ||                   \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
@@ -2196,6 +2265,7 @@ static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
     int ret;
     size_t len_bytes = ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
     unsigned char *p = ssl->handshake->premaster + pms_offset;
+    mbedtls_pk_context * peer_pk;
 
     if( offset + len_bytes > MBEDTLS_SSL_OUT_CONTENT_LEN )
     {
@@ -2221,23 +2291,28 @@ static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
 
     ssl->handshake->pmslen = 48;
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
     if( ssl->session_negotiate->peer_cert == NULL )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
-        return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+        /* Should never happen */
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
     }
+    peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
     /*
      * Now write it out, encrypted
      */
-    if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
-                MBEDTLS_PK_RSA ) )
+    if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_RSA ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
         return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
     }
 
-    if( ( ret = mbedtls_pk_encrypt( &ssl->session_negotiate->peer_cert->pk,
+    if( ( ret = mbedtls_pk_encrypt( peer_pk,
                             p, ssl->handshake->pmslen,
                             ssl->out_msg + offset + len_bytes, olen,
                             MBEDTLS_SSL_OUT_CONTENT_LEN - offset - len_bytes,
@@ -2257,6 +2332,10 @@ static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
     }
 #endif
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    /* We don't need the peer's public key anymore. Free it. */
+    mbedtls_pk_free( peer_pk );
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
     return( 0 );
 }
 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
@@ -2332,21 +2411,27 @@ static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
 {
     int ret;
     const mbedtls_ecp_keypair *peer_key;
+    mbedtls_pk_context * peer_pk;
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
     if( ssl->session_negotiate->peer_cert == NULL )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
-        return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+        /* Should never happen */
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
     }
+    peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
-    if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
-                     MBEDTLS_PK_ECKEY ) )
+    if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_ECKEY ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
         return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
     }
 
-    peer_key = mbedtls_pk_ec( ssl->session_negotiate->peer_cert->pk );
+    peer_key = mbedtls_pk_ec( *peer_pk );
 
     if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
                                  MBEDTLS_ECDH_THEIRS ) ) != 0 )
@@ -2361,6 +2446,13 @@ static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
     }
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    /* We don't need the peer's public key anymore. Free it,
+     * so that more RAM is available for upcoming expensive
+     * operations like ECDHE. */
+    mbedtls_pk_free( peer_pk );
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
     return( ret );
 }
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
@@ -2503,6 +2595,24 @@ start_processing:
     else
 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
           MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
+#if defined(MBEDTLS_USE_PSA_CRYPTO) &&                           \
+        ( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||     \
+          defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) )
+    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
+        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
+    {
+        if( ssl_parse_server_ecdh_params_psa( ssl, &p, end ) != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                            MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+            return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+        }
+    }
+    else
+#endif /* MBEDTLS_USE_PSA_CRYPTO &&
+            ( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
+              MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
@@ -2553,6 +2663,8 @@ start_processing:
         size_t params_len = p - params;
         void *rs_ctx = NULL;
 
+        mbedtls_pk_context * peer_pk;
+
         /*
          * Handle the digitally-signed structure
          */
@@ -2655,18 +2767,22 @@ start_processing:
 
         MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+        peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
         if( ssl->session_negotiate->peer_cert == NULL )
         {
-            MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
-            return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+            /* Should never happen */
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+            return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
         }
+        peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
         /*
          * Verify signature
          */
-        if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
+        if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
@@ -2679,8 +2795,7 @@ start_processing:
             rs_ctx = &ssl->handshake->ecrs_ctx.pk;
 #endif
 
-        if( ( ret = mbedtls_pk_verify_restartable(
-                        &ssl->session_negotiate->peer_cert->pk,
+        if( ( ret = mbedtls_pk_verify_restartable( peer_pk,
                         md_alg, hash, hashlen, p, sig_len, rs_ctx ) ) != 0 )
         {
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
@@ -2695,6 +2810,13 @@ start_processing:
 #endif
             return( ret );
         }
+
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+        /* We don't need the peer's public key anymore. Free it,
+         * so that more RAM is available for upcoming expensive
+         * operations like ECDHE. */
+        mbedtls_pk_free( peer_pk );
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
     }
 #endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
 
@@ -2931,7 +3053,9 @@ static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
 static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
 {
     int ret;
-    size_t i, n;
+
+    size_t header_len;
+    size_t content_len;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
         ssl->transform_negotiate->ciphersuite_info;
 
@@ -2943,16 +3067,16 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
         /*
          * DHM key exchange -- send G^X mod P
          */
-        n = ssl->handshake->dhm_ctx.len;
+        content_len = ssl->handshake->dhm_ctx.len;
 
-        ssl->out_msg[4] = (unsigned char)( n >> 8 );
-        ssl->out_msg[5] = (unsigned char)( n      );
-        i = 6;
+        ssl->out_msg[4] = (unsigned char)( content_len >> 8 );
+        ssl->out_msg[5] = (unsigned char)( content_len      );
+        header_len = 6;
 
         ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
-                                (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
-                               &ssl->out_msg[i], n,
-                                ssl->conf->f_rng, ssl->conf->p_rng );
+                           (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
+                           &ssl->out_msg[header_len], content_len,
+                           ssl->conf->f_rng, ssl->conf->p_rng );
         if( ret != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
@@ -2963,10 +3087,10 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
 
         if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
-                                      ssl->handshake->premaster,
-                                      MBEDTLS_PREMASTER_SIZE,
-                                     &ssl->handshake->pmslen,
-                                      ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
+                                   ssl->handshake->premaster,
+                                   MBEDTLS_PREMASTER_SIZE,
+                                   &ssl->handshake->pmslen,
+                                   ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
             return( ret );
@@ -2976,6 +3100,119 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
     }
     else
 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
+#if defined(MBEDTLS_USE_PSA_CRYPTO) &&                           \
+        ( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||     \
+          defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) )
+    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
+        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
+    {
+        psa_status_t status;
+        psa_key_policy_t policy;
+
+        mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+
+        unsigned char own_pubkey[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
+        size_t own_pubkey_len;
+        unsigned char *own_pubkey_ecpoint;
+        size_t own_pubkey_ecpoint_len;
+
+        psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
+
+        header_len = 4;
+
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based ECDH computation." ) );
+
+        /*
+         * Generate EC private key for ECDHE exchange.
+         */
+
+        /* Allocate a new key slot for the private key. */
+
+        status = psa_allocate_key( &handshake->ecdh_psa_privkey );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        /* The master secret is obtained from the shared ECDH secret by
+         * applying the TLS 1.2 PRF with a specific salt and label. While
+         * the PSA Crypto API encourages combining key agreement schemes
+         * such as ECDH with fixed KDFs such as TLS 1.2 PRF, it does not
+         * yet support the provisioning of salt + label to the KDF.
+         * For the time being, we therefore need to split the computation
+         * of the ECDH secret and the application of the TLS 1.2 PRF. */
+        policy = psa_key_policy_init();
+        psa_key_policy_set_usage( &policy,
+                                  PSA_KEY_USAGE_DERIVE,
+                                  PSA_ALG_ECDH( PSA_ALG_SELECT_RAW ) );
+        status = psa_set_key_policy( handshake->ecdh_psa_privkey, &policy );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        /* Generate ECDH private key. */
+        status = psa_generate_key( handshake->ecdh_psa_privkey,
+                          PSA_KEY_TYPE_ECC_KEYPAIR( handshake->ecdh_psa_curve ),
+                          MBEDTLS_PSA_ECC_KEY_BITS_OF_CURVE( handshake->ecdh_psa_curve ),
+                          NULL, 0 );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        /* Export the public part of the ECDH private key from PSA
+         * and convert it to ECPoint format used in ClientKeyExchange. */
+        status = psa_export_public_key( handshake->ecdh_psa_privkey,
+                                        own_pubkey, sizeof( own_pubkey ),
+                                        &own_pubkey_len );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        if( mbedtls_psa_tls_psa_ec_to_ecpoint( own_pubkey,
+                                               own_pubkey_len,
+                                               &own_pubkey_ecpoint,
+                                               &own_pubkey_ecpoint_len ) != 0 )
+        {
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+        }
+
+        /* Copy ECPoint structure to outgoing message buffer. */
+        ssl->out_msg[header_len] = own_pubkey_ecpoint_len;
+        memcpy( ssl->out_msg + header_len + 1,
+                own_pubkey_ecpoint, own_pubkey_ecpoint_len );
+        content_len = own_pubkey_ecpoint_len + 1;
+
+        /* Compute ECDH shared secret. */
+        status = psa_key_agreement( &generator,
+                                    handshake->ecdh_psa_privkey,
+                                    handshake->ecdh_psa_peerkey,
+                                    handshake->ecdh_psa_peerkey_len,
+                                    PSA_ALG_ECDH( PSA_ALG_SELECT_RAW ) );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        /* The ECDH secret is the premaster secret used for key derivation. */
+
+        ssl->handshake->pmslen =
+            MBEDTLS_PSA_ECC_KEY_BYTES_OF_CURVE( handshake->ecdh_psa_curve );
+
+        status = psa_generator_read( &generator,
+                                     ssl->handshake->premaster,
+                                     ssl->handshake->pmslen );
+        if( status != PSA_SUCCESS )
+        {
+            psa_generator_abort( &generator );
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+        }
+
+        status = psa_generator_abort( &generator );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+        status = psa_destroy_key( handshake->ecdh_psa_privkey );
+        if( status != PSA_SUCCESS )
+            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+        handshake->ecdh_psa_privkey = 0;
+    }
+    else
+#endif /* MBEDTLS_USE_PSA_CRYPTO &&
+            ( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
+              MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) ||                   \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||                      \
@@ -2988,7 +3225,7 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
         /*
          * ECDH key exchange -- send client public value
          */
-        i = 4;
+        header_len = 4;
 
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
         if( ssl->handshake->ecrs_enabled )
@@ -3001,8 +3238,8 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
 #endif
 
         ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
-                                &n,
-                                &ssl->out_msg[i], 1000,
+                                &content_len,
+                                &ssl->out_msg[header_len], 1000,
                                 ssl->conf->f_rng, ssl->conf->p_rng );
         if( ret != 0 )
         {
@@ -3014,24 +3251,25 @@ static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
             return( ret );
         }
 
-        MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_Q );
 
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
         if( ssl->handshake->ecrs_enabled )
         {
-            ssl->handshake->ecrs_n = n;
+            ssl->handshake->ecrs_n = content_len;
             ssl->handshake->ecrs_state = ssl_ecrs_cke_ecdh_calc_secret;
         }
 
 ecdh_calc_secret:
         if( ssl->handshake->ecrs_enabled )
-            n = ssl->handshake->ecrs_n;
+            content_len = ssl->handshake->ecrs_n;
 #endif
         if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
-                                      &ssl->handshake->pmslen,
-                                       ssl->handshake->premaster,
-                                       MBEDTLS_MPI_MAX_SIZE,
-                                       ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
+                                   &ssl->handshake->pmslen,
+                                   ssl->handshake->premaster,
+                                   MBEDTLS_MPI_MAX_SIZE,
+                                   ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
@@ -3041,7 +3279,8 @@ ecdh_calc_secret:
             return( ret );
         }
 
-        MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_Z );
     }
     else
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
@@ -3062,26 +3301,28 @@ ecdh_calc_secret:
             return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
         }
 
-        i = 4;
-        n = ssl->conf->psk_identity_len;
+        header_len = 4;
+        content_len = ssl->conf->psk_identity_len;
 
-        if( i + 2 + n > MBEDTLS_SSL_OUT_CONTENT_LEN )
+        if( header_len + 2 + content_len > MBEDTLS_SSL_OUT_CONTENT_LEN )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity too long or "
                                         "SSL buffer too short" ) );
             return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
         }
 
-        ssl->out_msg[i++] = (unsigned char)( n >> 8 );
-        ssl->out_msg[i++] = (unsigned char)( n      );
+        ssl->out_msg[header_len++] = (unsigned char)( content_len >> 8 );
+        ssl->out_msg[header_len++] = (unsigned char)( content_len      );
 
-        memcpy( ssl->out_msg + i, ssl->conf->psk_identity, ssl->conf->psk_identity_len );
-        i += ssl->conf->psk_identity_len;
+        memcpy( ssl->out_msg + header_len,
+                ssl->conf->psk_identity,
+                ssl->conf->psk_identity_len );
+        header_len += ssl->conf->psk_identity_len;
 
 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
         if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK )
         {
-            n = 0;
+            content_len = 0;
         }
         else
 #endif
@@ -3094,7 +3335,8 @@ ecdh_calc_secret:
                 return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 
-            if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 2 ) ) != 0 )
+            if( ( ret = ssl_write_encrypted_pms( ssl, header_len,
+                                                 &content_len, 2 ) ) != 0 )
                 return( ret );
         }
         else
@@ -3111,21 +3353,22 @@ ecdh_calc_secret:
             /*
              * ClientDiffieHellmanPublic public (DHM send G^X mod P)
              */
-            n = ssl->handshake->dhm_ctx.len;
+            content_len = ssl->handshake->dhm_ctx.len;
 
-            if( i + 2 + n > MBEDTLS_SSL_OUT_CONTENT_LEN )
+            if( header_len + 2 + content_len >
+                MBEDTLS_SSL_OUT_CONTENT_LEN )
             {
                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long"
                                             " or SSL buffer too short" ) );
                 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
             }
 
-            ssl->out_msg[i++] = (unsigned char)( n >> 8 );
-            ssl->out_msg[i++] = (unsigned char)( n      );
+            ssl->out_msg[header_len++] = (unsigned char)( content_len >> 8 );
+            ssl->out_msg[header_len++] = (unsigned char)( content_len      );
 
             ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
                     (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
-                    &ssl->out_msg[i], n,
+                    &ssl->out_msg[header_len], content_len,
                     ssl->conf->f_rng, ssl->conf->p_rng );
             if( ret != 0 )
             {
@@ -3147,8 +3390,10 @@ ecdh_calc_secret:
             /*
              * ClientECDiffieHellmanPublic public;
              */
-            ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
-                    &ssl->out_msg[i], MBEDTLS_SSL_OUT_CONTENT_LEN - i,
+            ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
+                    &content_len,
+                    &ssl->out_msg[header_len],
+                    MBEDTLS_SSL_OUT_CONTENT_LEN - header_len,
                     ssl->conf->f_rng, ssl->conf->p_rng );
             if( ret != 0 )
             {
@@ -3156,7 +3401,8 @@ ecdh_calc_secret:
                 return( ret );
             }
 
-            MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
+            MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                    MBEDTLS_DEBUG_ECDH_Q );
         }
         else
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
@@ -3188,8 +3434,9 @@ ecdh_calc_secret:
 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
     {
-        i = 4;
-        if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 0 ) ) != 0 )
+        header_len = 4;
+        if( ( ret = ssl_write_encrypted_pms( ssl, header_len,
+                                             &content_len, 0 ) ) != 0 )
             return( ret );
     }
     else
@@ -3197,10 +3444,12 @@ ecdh_calc_secret:
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
     {
-        i = 4;
+        header_len = 4;
 
         ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
-                ssl->out_msg + i, MBEDTLS_SSL_OUT_CONTENT_LEN - i, &n,
+                ssl->out_msg + header_len,
+                MBEDTLS_SSL_OUT_CONTENT_LEN - header_len,
+                &content_len,
                 ssl->conf->f_rng, ssl->conf->p_rng );
         if( ret != 0 )
         {
@@ -3225,7 +3474,7 @@ ecdh_calc_secret:
         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
     }
 
-    ssl->out_msglen  = i + n;
+    ssl->out_msglen  = header_len + content_len;
     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
     ssl->out_msg[0]  = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE;
 
@@ -3242,12 +3491,7 @@ ecdh_calc_secret:
     return( 0 );
 }
 
-#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)       && \
-    !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)   && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)  && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
@@ -3262,11 +3506,7 @@ static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
         return( ret );
     }
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
         ssl->state++;
@@ -3276,7 +3516,7 @@ static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
-#else
+#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
@@ -3305,11 +3545,7 @@ static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
         return( ret );
     }
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
         ssl->state++;
@@ -3452,12 +3688,7 @@ sign:
 
     return( ret );
 }
-#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
 static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
@@ -3531,6 +3762,15 @@ static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
     if( ticket_len == 0 )
         return( 0 );
 
+    if( ssl->session != NULL && ssl->session->ticket != NULL )
+    {
+        mbedtls_platform_zeroize( ssl->session->ticket,
+                                  ssl->session->ticket_len );
+        mbedtls_free( ssl->session->ticket );
+        ssl->session->ticket = NULL;
+        ssl->session->ticket_len = 0;
+    }
+
     mbedtls_platform_zeroize( ssl->session_negotiate->ticket,
                               ssl->session_negotiate->ticket_len );
     mbedtls_free( ssl->session_negotiate->ticket );
diff --git a/features/mbedtls/src/ssl_srv.c b/features/mbedtls/src/ssl_srv.c
index 4d99f884dd..c969089566 100644
--- a/features/mbedtls/src/ssl_srv.c
+++ b/features/mbedtls/src/ssl_srv.c
@@ -1489,7 +1489,7 @@ read_record_header:
      */
 
     /*
-     * Minimal length (with everything empty and extensions ommitted) is
+     * Minimal length (with everything empty and extensions omitted) is
      * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can
      * read at least up to session id length without worrying.
      */
@@ -2680,12 +2680,7 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
     return( ret );
 }
 
-#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)       && \
-    !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)   && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)  && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
@@ -2693,11 +2688,7 @@ static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
         ssl->state++;
@@ -2707,7 +2698,7 @@ static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
-#else
+#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
@@ -2731,11 +2722,7 @@ static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
 #endif
         authmode = ssl->conf->authmode;
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ||
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) ||
         authmode == MBEDTLS_SSL_VERIFY_NONE )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
@@ -2874,12 +2861,7 @@ static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
 
     return( ret );
 }
-#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
@@ -3088,8 +3070,8 @@ curve_matching_done:
 
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDHE curve: %s", (*curve)->name ) );
 
-        if( ( ret = mbedtls_ecp_group_load( &ssl->handshake->ecdh_ctx.grp,
-                                       (*curve)->grp_id ) ) != 0 )
+        if( ( ret = mbedtls_ecdh_setup( &ssl->handshake->ecdh_ctx,
+                                        (*curve)->grp_id ) ) != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecp_group_load", ret );
             return( ret );
@@ -3111,7 +3093,8 @@ curve_matching_done:
 
         ssl->out_msglen += len;
 
-        MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q ", &ssl->handshake->ecdh_ctx.Q );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_Q );
     }
 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED */
 
@@ -3832,7 +3815,8 @@ static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
         }
 
-        MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_QP );
 
         if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
                                       &ssl->handshake->pmslen,
@@ -3844,7 +3828,8 @@ static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS );
         }
 
-        MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z  ", &ssl->handshake->ecdh_ctx.z );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_Z );
     }
     else
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
@@ -3982,7 +3967,8 @@ static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
 #endif
 
-        MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_QP );
 
         if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
                         ciphersuite_info->key_exchange ) ) != 0 )
@@ -4044,12 +4030,7 @@ static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
     return( 0 );
 }
 
-#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)       && \
-    !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)   && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)  && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
@@ -4057,11 +4038,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
         ssl->state++;
@@ -4071,7 +4048,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
-#else
+#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
@@ -4085,21 +4062,33 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
     mbedtls_md_type_t md_alg;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
         ssl->transform_negotiate->ciphersuite_info;
+    mbedtls_pk_context * peer_pk;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ||
-        ssl->session_negotiate->peer_cert == NULL )
+    if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
         ssl->state++;
         return( 0 );
     }
 
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    if( ssl->session_negotiate->peer_cert == NULL )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+        ssl->state++;
+        return( 0 );
+    }
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    if( ssl->session_negotiate->peer_cert_digest == NULL )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+        ssl->state++;
+        return( 0 );
+    }
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
     /* Read the message without adding it to the checksum */
     ret = mbedtls_ssl_read_record( ssl, 0 /* no checksum update */ );
     if( 0 != ret )
@@ -4120,6 +4109,17 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
 
     i = mbedtls_ssl_hs_hdr_len( ssl );
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    if( ssl->session_negotiate->peer_cert == NULL )
+    {
+        /* Should never happen */
+        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+    }
+    peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
     /*
      *  struct {
      *     SignatureAndHashAlgorithm algorithm; -- TLS 1.2 only
@@ -4134,8 +4134,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
         hashlen = 36;
 
         /* For ECDSA, use SHA-1, not MD-5 + SHA-1 */
-        if( mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
-                        MBEDTLS_PK_ECDSA ) )
+        if( mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_ECDSA ) )
         {
             hash_start += 16;
             hashlen -= 16;
@@ -4190,7 +4189,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
         /*
          * Check the certificate's key type matches the signature alg
          */
-        if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
+        if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "sig_alg doesn't match cert key" ) );
             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
@@ -4223,7 +4222,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
     /* Calculate hash and verify signature */
     ssl->handshake->calc_verify( ssl, hash );
 
-    if( ( ret = mbedtls_pk_verify( &ssl->session_negotiate->peer_cert->pk,
+    if( ( ret = mbedtls_pk_verify( peer_pk,
                            md_alg, hash_start, hashlen,
                            ssl->in_msg + i, sig_len ) ) != 0 )
     {
@@ -4237,12 +4236,7 @@ static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
 
     return( ret );
 }
-#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
 static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
diff --git a/features/mbedtls/src/ssl_ticket.c b/features/mbedtls/src/ssl_ticket.c
index 9fc690f4c6..ed65bcd639 100644
--- a/features/mbedtls/src/ssl_ticket.c
+++ b/features/mbedtls/src/ssl_ticket.c
@@ -187,9 +187,16 @@ int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
 
 /*
  * Serialize a session in the following format:
- *  0   .   n-1     session structure, n = sizeof(mbedtls_ssl_session)
- *  n   .   n+2     peer_cert length = m (0 if no certificate)
- *  n+3 .   n+2+m   peer cert ASN.1
+ *
+ * - If MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is enabled:
+ *    0       .   n-1   session structure, n = sizeof(mbedtls_ssl_session)
+ *    n       .   n+2   peer_cert length = m (0 if no certificate)
+ *    n+3     .   n+2+m peer cert ASN.1
+ *
+ * - If MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled:
+ *    0       .   n-1   session structure, n = sizeof(mbedtls_ssl_session)
+ *    n       .   n     length of peer certificate digest = k (0 if no digest)
+ *    n+1     .   n+k   peer certificate digest (digest type encoded in session)
  */
 static int ssl_save_session( const mbedtls_ssl_session *session,
                              unsigned char *buf, size_t buf_len,
@@ -198,17 +205,25 @@ static int ssl_save_session( const mbedtls_ssl_session *session,
     unsigned char *p = buf;
     size_t left = buf_len;
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     size_t cert_len;
+#else
+    size_t cert_digest_len;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
     if( left < sizeof( mbedtls_ssl_session ) )
         return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
 
+    /* This also copies the values of pointer fields in the
+     * session to be serialized, but they'll be ignored when
+     * loading the session through ssl_load_session(). */
     memcpy( p, session, sizeof( mbedtls_ssl_session ) );
     p += sizeof( mbedtls_ssl_session );
     left -= sizeof( mbedtls_ssl_session );
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     if( session->peer_cert == NULL )
         cert_len = 0;
     else
@@ -217,14 +232,34 @@ static int ssl_save_session( const mbedtls_ssl_session *session,
     if( left < 3 + cert_len )
         return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
 
-    *p++ = (unsigned char)( cert_len >> 16 & 0xFF );
-    *p++ = (unsigned char)( cert_len >>  8 & 0xFF );
-    *p++ = (unsigned char)( cert_len       & 0xFF );
+    *p++ = (unsigned char)( ( cert_len >> 16 ) & 0xFF );
+    *p++ = (unsigned char)( ( cert_len >>  8 ) & 0xFF );
+    *p++ = (unsigned char)( ( cert_len       ) & 0xFF );
+    left -= 3;
 
     if( session->peer_cert != NULL )
         memcpy( p, session->peer_cert->raw.p, cert_len );
 
     p += cert_len;
+    left -= cert_len;
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    if( session->peer_cert_digest != NULL )
+        cert_digest_len = 0;
+    else
+        cert_digest_len = session->peer_cert_digest_len;
+
+    if( left < 1 + cert_digest_len )
+        return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+
+    *p++ = (unsigned char) cert_digest_len;
+    left--;
+
+    if( session->peer_cert_digest != NULL )
+        memcpy( p, session->peer_cert_digest, cert_digest_len );
+
+    p    += cert_digest_len;
+    left -= cert_digest_len;
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
     *olen = p - buf;
@@ -241,31 +276,46 @@ static int ssl_load_session( mbedtls_ssl_session *session,
     const unsigned char *p = buf;
     const unsigned char * const end = buf + len;
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     size_t cert_len;
+#else
+    size_t cert_digest_len;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
-    if( p + sizeof( mbedtls_ssl_session ) > end )
+    if( sizeof( mbedtls_ssl_session ) > (size_t)( end - p ) )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
     memcpy( session, p, sizeof( mbedtls_ssl_session ) );
     p += sizeof( mbedtls_ssl_session );
 
+    /* Non-NULL pointer fields of `session` are meaningless
+     * and potentially harmful. Zeroize them for safety. */
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
-    if( p + 3 > end )
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    session->peer_cert = NULL;
+#else
+    session->peer_cert_digest = NULL;
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+#endif /* MBEDTLS_X509_CRT_PARSE_C */
+#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
+    session->ticket = NULL;
+#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    /* Deserialize CRT from the end of the ticket. */
+    if( 3 > (size_t)( end - p ) )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
     cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
     p += 3;
 
-    if( cert_len == 0 )
-    {
-        session->peer_cert = NULL;
-    }
-    else
+    if( cert_len != 0 )
     {
         int ret;
 
-        if( p + cert_len > end )
+        if( cert_len > (size_t)( end - p ) )
             return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
         session->peer_cert = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
@@ -276,7 +326,7 @@ static int ssl_load_session( mbedtls_ssl_session *session,
         mbedtls_x509_crt_init( session->peer_cert );
 
         if( ( ret = mbedtls_x509_crt_parse_der( session->peer_cert,
-                                        p, cert_len ) ) != 0 )
+                                                p, cert_len ) ) != 0 )
         {
             mbedtls_x509_crt_free( session->peer_cert );
             mbedtls_free( session->peer_cert );
@@ -286,6 +336,30 @@ static int ssl_load_session( mbedtls_ssl_session *session,
 
         p += cert_len;
     }
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    /* Deserialize CRT digest from the end of the ticket. */
+    if( 1 > (size_t)( end - p ) )
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+    cert_digest_len = (size_t) p[0];
+    p++;
+
+    if( cert_digest_len != 0 )
+    {
+        if( cert_digest_len > (size_t)( end - p ) ||
+            cert_digest_len != session->peer_cert_digest_len )
+        {
+            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+        }
+
+        session->peer_cert_digest = mbedtls_calloc( 1, cert_digest_len );
+        if( session->peer_cert_digest == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+
+        memcpy( session->peer_cert_digest, p, cert_digest_len );
+        p += cert_digest_len;
+    }
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
     if( p != end )
diff --git a/features/mbedtls/src/ssl_tls.c b/features/mbedtls/src/ssl_tls.c
index d14434af05..660d548e45 100644
--- a/features/mbedtls/src/ssl_tls.c
+++ b/features/mbedtls/src/ssl_tls.c
@@ -50,10 +50,19 @@
 
 #include <string.h>
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "mbedtls/psa_util.h"
+#include "psa/crypto.h"
+#endif
+
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 #include "mbedtls/oid.h"
 #endif
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "mbedtls/psa_util.h"
+#endif
+
 static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl );
 static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl );
 
@@ -270,13 +279,15 @@ static unsigned int ssl_mfl_code_to_length( int mfl )
 }
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
-#if defined(MBEDTLS_SSL_CLI_C)
-static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session *src )
+int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
+                              const mbedtls_ssl_session *src )
 {
     mbedtls_ssl_session_free( dst );
     memcpy( dst, src, sizeof( mbedtls_ssl_session ) );
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
+
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     if( src->peer_cert != NULL )
     {
         int ret;
@@ -295,6 +306,21 @@ static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session
             return( ret );
         }
     }
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    if( src->peer_cert_digest != NULL )
+    {
+        dst->peer_cert_digest =
+            mbedtls_calloc( 1, src->peer_cert_digest_len );
+        if( dst->peer_cert_digest == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+
+        memcpy( dst->peer_cert_digest, src->peer_cert_digest,
+                src->peer_cert_digest_len );
+        dst->peer_cert_digest_type = src->peer_cert_digest_type;
+        dst->peer_cert_digest_len = src->peer_cert_digest_len;
+    }
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
@@ -310,7 +336,6 @@ static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session
 
     return( 0 );
 }
-#endif /* MBEDTLS_SSL_CLI_C */
 
 #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
 int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl,
@@ -490,6 +515,76 @@ static int tls1_prf( const unsigned char *secret, size_t slen,
 #endif /* MBEDTLS_SSL_PROTO_TLS1) || MBEDTLS_SSL_PROTO_TLS1_1 */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+static int tls_prf_generic( mbedtls_md_type_t md_type,
+                            const unsigned char *secret, size_t slen,
+                            const char *label,
+                            const unsigned char *random, size_t rlen,
+                            unsigned char *dstbuf, size_t dlen )
+{
+    psa_status_t status;
+    psa_algorithm_t alg;
+    psa_key_policy_t policy;
+    psa_key_handle_t master_slot;
+    psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
+
+    if( ( status = psa_allocate_key( &master_slot ) ) != PSA_SUCCESS )
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+    if( md_type == MBEDTLS_MD_SHA384 )
+        alg = PSA_ALG_TLS12_PRF(PSA_ALG_SHA_384);
+    else
+        alg = PSA_ALG_TLS12_PRF(PSA_ALG_SHA_256);
+
+    policy = psa_key_policy_init();
+    psa_key_policy_set_usage( &policy,
+                              PSA_KEY_USAGE_DERIVE,
+                              alg );
+    status = psa_set_key_policy( master_slot, &policy );
+    if( status != PSA_SUCCESS )
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+    status = psa_import_key( master_slot, PSA_KEY_TYPE_DERIVE, secret, slen );
+    if( status != PSA_SUCCESS )
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+    status = psa_key_derivation( &generator,
+                                 master_slot, alg,
+                                 random, rlen,
+                                 (unsigned char const *) label,
+                                 (size_t) strlen( label ),
+                                 dlen );
+    if( status != PSA_SUCCESS )
+    {
+        psa_generator_abort( &generator );
+        psa_destroy_key( master_slot );
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+    }
+
+    status = psa_generator_read( &generator, dstbuf, dlen );
+    if( status != PSA_SUCCESS )
+    {
+        psa_generator_abort( &generator );
+        psa_destroy_key( master_slot );
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+    }
+
+    status = psa_generator_abort( &generator );
+    if( status != PSA_SUCCESS )
+    {
+        psa_destroy_key( master_slot );
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+    }
+
+    status = psa_destroy_key( master_slot );
+    if( status != PSA_SUCCESS )
+        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+
+    return( 0 );
+}
+
+#else /* MBEDTLS_USE_PSA_CRYPTO */
+
 static int tls_prf_generic( mbedtls_md_type_t md_type,
                             const unsigned char *secret, size_t slen,
                             const char *label,
@@ -552,7 +647,7 @@ static int tls_prf_generic( mbedtls_md_type_t md_type,
 
     return( 0 );
 }
-
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
 #if defined(MBEDTLS_SHA256_C)
 static int tls_prf_sha256( const unsigned char *secret, size_t slen,
                            const char *label,
@@ -798,7 +893,7 @@ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
             psa_status_t status;
             psa_algorithm_t alg;
             psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
-            psa_key_slot_t psk;
+            psa_key_handle_t psk;
 
             MBEDTLS_SSL_DEBUG_MSG( 2, ( "perform PSA-based PSK-to-MS expansion" ) );
 
@@ -1347,7 +1442,7 @@ void ssl_calc_verify_tls( mbedtls_ssl_context *ssl, unsigned char hash[36] )
     mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
     mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
 
-     mbedtls_md5_finish_ret( &md5,  hash );
+    mbedtls_md5_finish_ret( &md5,  hash );
     mbedtls_sha1_finish_ret( &sha1, hash + 16 );
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 );
@@ -1364,6 +1459,28 @@ void ssl_calc_verify_tls( mbedtls_ssl_context *ssl, unsigned char hash[36] )
 #if defined(MBEDTLS_SHA256_C)
 void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *ssl, unsigned char hash[32] )
 {
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    size_t hash_size;
+    psa_status_t status;
+    psa_hash_operation_t sha256_psa = psa_hash_operation_init();
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> PSA calc verify sha256" ) );
+    status = psa_hash_clone( &ssl->handshake->fin_sha256_psa, &sha256_psa );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash clone failed" ) );
+        return;
+    }
+
+    status = psa_hash_finish( &sha256_psa, hash, 32, &hash_size );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash finish failed" ) );
+        return;
+    }
+    MBEDTLS_SSL_DEBUG_BUF( 3, "PSA calculated verify result", hash, 32 );
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= PSA calc verify" ) );
+#else
     mbedtls_sha256_context sha256;
 
     mbedtls_sha256_init( &sha256 );
@@ -1377,7 +1494,7 @@ void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *ssl, unsigned char hash[32
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
 
     mbedtls_sha256_free( &sha256 );
-
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
     return;
 }
 #endif /* MBEDTLS_SHA256_C */
@@ -1385,6 +1502,28 @@ void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *ssl, unsigned char hash[32
 #if defined(MBEDTLS_SHA512_C)
 void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *ssl, unsigned char hash[48] )
 {
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    size_t hash_size;
+    psa_status_t status;
+    psa_hash_operation_t sha384_psa = psa_hash_operation_init();
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> PSA calc verify sha384" ) );
+    status = psa_hash_clone( &ssl->handshake->fin_sha384_psa, &sha384_psa );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash clone failed" ) );
+        return;
+    }
+
+    status = psa_hash_finish( &sha384_psa, hash, 48, &hash_size );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash finish failed" ) );
+        return;
+    }
+    MBEDTLS_SSL_DEBUG_BUF( 3, "PSA calculated verify result", hash, 48 );
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= PSA calc verify" ) );
+#else
     mbedtls_sha512_context sha512;
 
     mbedtls_sha512_init( &sha512 );
@@ -1398,7 +1537,7 @@ void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *ssl, unsigned char hash[48
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
 
     mbedtls_sha512_free( &sha512 );
-
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
     return;
 }
 #endif /* MBEDTLS_SHA512_C */
@@ -1499,7 +1638,8 @@ int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exch
         *(p++) = (unsigned char)( zlen      );
         p += zlen;
 
-        MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
+        MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+                                MBEDTLS_DEBUG_ECDH_Z );
     }
     else
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
@@ -2771,7 +2911,7 @@ int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want )
         }
 
         /*
-         * A record can't be split accross datagrams. If we need to read but
+         * A record can't be split across datagrams. If we need to read but
          * are not at the beginning of a new record, the caller did something
          * wrong.
          */
@@ -3366,8 +3506,10 @@ int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
         }
     }
 
-    if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
-        hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST &&
+    /* Whenever we send anything different from a
+     * HelloRequest we should be in a handshake - double check. */
+    if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+            hs_type          == MBEDTLS_SSL_HS_HELLO_REQUEST ) &&
         ssl->handshake == NULL )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
@@ -3461,8 +3603,8 @@ int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
     /* Either send now, or just save to be sent (and resent) later */
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
-        ( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
-          hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) )
+        ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+            hs_type          == MBEDTLS_SSL_HS_HELLO_REQUEST ) )
     {
         if( ( ret = ssl_flight_append( ssl ) ) != 0 )
         {
@@ -5428,16 +5570,33 @@ int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
     return( 0 );
 }
 
+#if defined(MBEDTLS_X509_CRT_PARSE_C)
+static void ssl_clear_peer_cert( mbedtls_ssl_session *session )
+{
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    if( session->peer_cert != NULL )
+    {
+        mbedtls_x509_crt_free( session->peer_cert );
+        mbedtls_free( session->peer_cert );
+        session->peer_cert = NULL;
+    }
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    if( session->peer_cert_digest != NULL )
+    {
+        /* Zeroization is not necessary. */
+        mbedtls_free( session->peer_cert_digest );
+        session->peer_cert_digest      = NULL;
+        session->peer_cert_digest_type = MBEDTLS_MD_NONE;
+        session->peer_cert_digest_len  = 0;
+    }
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+}
+#endif /* MBEDTLS_X509_CRT_PARSE_C */
+
 /*
  * Handshake functions
  */
-#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)         && \
-    !defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)     && \
-    !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)     && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED)   && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)    && \
-    !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+#if !defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
 /* No certificate support -> dummy functions */
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
 {
@@ -5445,10 +5604,7 @@ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
         ssl->state++;
@@ -5465,10 +5621,7 @@ int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
         ssl->state++;
@@ -5479,7 +5632,7 @@ int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
 
-#else
+#else /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
 /* Some certificate support -> implement write and parse */
 
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
@@ -5491,10 +5644,7 @@ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
         ssl->state++;
@@ -5598,63 +5748,68 @@ write_msg:
     return( ret );
 }
 
+#if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C)
+
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+static int ssl_check_peer_crt_unchanged( mbedtls_ssl_context *ssl,
+                                         unsigned char *crt_buf,
+                                         size_t crt_buf_len )
+{
+    mbedtls_x509_crt const * const peer_crt = ssl->session->peer_cert;
+
+    if( peer_crt == NULL )
+        return( -1 );
+
+    if( peer_crt->raw.len != crt_buf_len )
+        return( -1 );
+
+    return( memcmp( peer_crt->raw.p, crt_buf, crt_buf_len ) );
+}
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+static int ssl_check_peer_crt_unchanged( mbedtls_ssl_context *ssl,
+                                         unsigned char *crt_buf,
+                                         size_t crt_buf_len )
+{
+    int ret;
+    unsigned char const * const peer_cert_digest =
+        ssl->session->peer_cert_digest;
+    mbedtls_md_type_t const peer_cert_digest_type =
+        ssl->session->peer_cert_digest_type;
+    mbedtls_md_info_t const * const digest_info =
+        mbedtls_md_info_from_type( peer_cert_digest_type );
+    unsigned char tmp_digest[MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN];
+    size_t digest_len;
+
+    if( peer_cert_digest == NULL || digest_info == NULL )
+        return( -1 );
+
+    digest_len = mbedtls_md_get_size( digest_info );
+    if( digest_len > MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN )
+        return( -1 );
+
+    ret = mbedtls_md( digest_info, crt_buf, crt_buf_len, tmp_digest );
+    if( ret != 0 )
+        return( -1 );
+
+    return( memcmp( tmp_digest, peer_cert_digest, digest_len ) );
+}
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+#endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */
+
 /*
  * Once the certificate message is read, parse it into a cert chain and
  * perform basic checks, but leave actual verification to the caller
  */
-static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl )
+static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl,
+                                        mbedtls_x509_crt *chain )
 {
     int ret;
+#if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C)
+    int crt_cnt=0;
+#endif
     size_t i, n;
     uint8_t alert;
 
-#if defined(MBEDTLS_SSL_SRV_C)
-#if defined(MBEDTLS_SSL_PROTO_SSL3)
-    /*
-     * Check if the client sent an empty certificate
-     */
-    if( ssl->conf->endpoint  == MBEDTLS_SSL_IS_SERVER &&
-        ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
-    {
-        if( ssl->in_msglen  == 2                        &&
-            ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT            &&
-            ssl->in_msg[0]  == MBEDTLS_SSL_ALERT_LEVEL_WARNING  &&
-            ssl->in_msg[1]  == MBEDTLS_SSL_ALERT_MSG_NO_CERT )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) );
-
-            /* The client was asked for a certificate but didn't send
-               one. The client should know what's going on, so we
-               don't send an alert. */
-            ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
-            return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
-        }
-    }
-#endif /* MBEDTLS_SSL_PROTO_SSL3 */
-
-#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
-    defined(MBEDTLS_SSL_PROTO_TLS1_2)
-    if( ssl->conf->endpoint  == MBEDTLS_SSL_IS_SERVER &&
-        ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
-    {
-        if( ssl->in_hslen   == 3 + mbedtls_ssl_hs_hdr_len( ssl ) &&
-            ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE    &&
-            ssl->in_msg[0]  == MBEDTLS_SSL_HS_CERTIFICATE   &&
-            memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), "\0\0\0", 3 ) == 0 )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) );
-
-            /* The client was asked for a certificate but didn't send
-               one. The client should know what's going on, so we
-               don't send an alert. */
-            ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
-            return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
-        }
-    }
-#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
-          MBEDTLS_SSL_PROTO_TLS1_2 */
-#endif /* MBEDTLS_SSL_SRV_C */
-
     if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
@@ -5688,43 +5843,32 @@ static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl )
         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
     }
 
-    /* In case we tried to reuse a session but it failed */
-    if( ssl->session_negotiate->peer_cert != NULL )
-    {
-        mbedtls_x509_crt_free( ssl->session_negotiate->peer_cert );
-        mbedtls_free( ssl->session_negotiate->peer_cert );
-    }
-
-    if( ( ssl->session_negotiate->peer_cert = mbedtls_calloc( 1,
-                    sizeof( mbedtls_x509_crt ) ) ) == NULL )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
-                       sizeof( mbedtls_x509_crt ) ) );
-        mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                        MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
-        return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
-    }
-
-    mbedtls_x509_crt_init( ssl->session_negotiate->peer_cert );
-
+    /* Make &ssl->in_msg[i] point to the beginning of the CRT chain. */
     i += 3;
 
+    /* Iterate through and parse the CRTs in the provided chain. */
     while( i < ssl->in_hslen )
     {
+        /* Check that there's room for the next CRT's length fields. */
         if ( i + 3 > ssl->in_hslen ) {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                           MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+            mbedtls_ssl_send_alert_message( ssl,
+                              MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                              MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
         }
+        /* In theory, the CRT can be up to 2**24 Bytes, but we don't support
+         * anything beyond 2**16 ~ 64K. */
         if( ssl->in_msg[i] != 0 )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+            mbedtls_ssl_send_alert_message( ssl,
+                            MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                            MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
         }
 
+        /* Read length of the next CRT in the chain. */
         n = ( (unsigned int) ssl->in_msg[i + 1] << 8 )
             | (unsigned int) ssl->in_msg[i + 2];
         i += 3;
@@ -5732,80 +5876,359 @@ static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl )
         if( n < 128 || i + n > ssl->in_hslen )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+            mbedtls_ssl_send_alert_message( ssl,
+                                 MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
         }
 
-        ret = mbedtls_x509_crt_parse_der( ssl->session_negotiate->peer_cert,
-                                  ssl->in_msg + i, n );
+        /* Check if we're handling the first CRT in the chain. */
+#if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C)
+        if( crt_cnt++ == 0 &&
+            ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
+            ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
+        {
+            /* During client-side renegotiation, check that the server's
+             * end-CRTs hasn't changed compared to the initial handshake,
+             * mitigating the triple handshake attack. On success, reuse
+             * the original end-CRT instead of parsing it again. */
+            MBEDTLS_SSL_DEBUG_MSG( 3, ( "Check that peer CRT hasn't changed during renegotiation" ) );
+            if( ssl_check_peer_crt_unchanged( ssl,
+                                              &ssl->in_msg[i],
+                                              n ) != 0 )
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) );
+                mbedtls_ssl_send_alert_message( ssl,
+                                                MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                                MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED );
+                return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
+            }
+
+            /* Now we can safely free the original chain. */
+            ssl_clear_peer_cert( ssl->session );
+        }
+#endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */
+
+        /* Parse the next certificate in the chain. */
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+        ret = mbedtls_x509_crt_parse_der( chain, ssl->in_msg + i, n );
+#else
+        /* If we don't need to store the CRT chain permanently, parse
+         * it in-place from the input buffer instead of making a copy. */
+        ret = mbedtls_x509_crt_parse_der_nocopy( chain, ssl->in_msg + i, n );
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
         switch( ret )
         {
-        case 0: /*ok*/
-        case MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND:
-            /* Ignore certificate with an unknown algorithm: maybe a
-               prior certificate was already trusted. */
-            break;
+            case 0: /*ok*/
+            case MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND:
+                /* Ignore certificate with an unknown algorithm: maybe a
+                   prior certificate was already trusted. */
+                break;
 
-        case MBEDTLS_ERR_X509_ALLOC_FAILED:
-            alert = MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR;
-            goto crt_parse_der_failed;
+            case MBEDTLS_ERR_X509_ALLOC_FAILED:
+                alert = MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR;
+                goto crt_parse_der_failed;
 
-        case MBEDTLS_ERR_X509_UNKNOWN_VERSION:
-            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            goto crt_parse_der_failed;
+            case MBEDTLS_ERR_X509_UNKNOWN_VERSION:
+                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+                goto crt_parse_der_failed;
 
-        default:
-            alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
-        crt_parse_der_failed:
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, alert );
-            MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
-            return( ret );
+            default:
+                alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
+            crt_parse_der_failed:
+                mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, alert );
+                MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
+                return( ret );
         }
 
         i += n;
     }
 
-    MBEDTLS_SSL_DEBUG_CRT( 3, "peer certificate", ssl->session_negotiate->peer_cert );
-
-    /*
-     * On client, make sure the server cert doesn't change during renego to
-     * avoid "triple handshake" attack: https://secure-resumption.com/
-     */
-#if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C)
-    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
-        ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
-    {
-        if( ssl->session->peer_cert == NULL )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED );
-            return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
-        }
-
-        if( ssl->session->peer_cert->raw.len !=
-            ssl->session_negotiate->peer_cert->raw.len ||
-            memcmp( ssl->session->peer_cert->raw.p,
-                    ssl->session_negotiate->peer_cert->raw.p,
-                    ssl->session->peer_cert->raw.len ) != 0 )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "server cert changed during renegotiation" ) );
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED );
-            return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
-        }
-    }
-#endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */
-
+    MBEDTLS_SSL_DEBUG_CRT( 3, "peer certificate", chain );
     return( 0 );
 }
 
-int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
+#if defined(MBEDTLS_SSL_SRV_C)
+static int ssl_srv_check_client_no_crt_notification( mbedtls_ssl_context *ssl )
+{
+    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
+        return( -1 );
+
+#if defined(MBEDTLS_SSL_PROTO_SSL3)
+    /*
+     * Check if the client sent an empty certificate
+     */
+    if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
+    {
+        if( ssl->in_msglen  == 2                        &&
+            ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT            &&
+            ssl->in_msg[0]  == MBEDTLS_SSL_ALERT_LEVEL_WARNING  &&
+            ssl->in_msg[1]  == MBEDTLS_SSL_ALERT_MSG_NO_CERT )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) );
+            return( 0 );
+        }
+
+        return( -1 );
+    }
+#endif /* MBEDTLS_SSL_PROTO_SSL3 */
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
+    defined(MBEDTLS_SSL_PROTO_TLS1_2)
+    if( ssl->in_hslen   == 3 + mbedtls_ssl_hs_hdr_len( ssl ) &&
+        ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE    &&
+        ssl->in_msg[0]  == MBEDTLS_SSL_HS_CERTIFICATE   &&
+        memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), "\0\0\0", 3 ) == 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) );
+        return( 0 );
+    }
+
+    return( -1 );
+#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
+          MBEDTLS_SSL_PROTO_TLS1_2 */
+}
+#endif /* MBEDTLS_SSL_SRV_C */
+
+/* Check if a certificate message is expected.
+ * Return either
+ * - SSL_CERTIFICATE_EXPECTED, or
+ * - SSL_CERTIFICATE_SKIP
+ * indicating whether a Certificate message is expected or not.
+ */
+#define SSL_CERTIFICATE_EXPECTED 0
+#define SSL_CERTIFICATE_SKIP     1
+static int ssl_parse_certificate_coordinate( mbedtls_ssl_context *ssl,
+                                             int authmode )
+{
+    const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+        ssl->transform_negotiate->ciphersuite_info;
+
+    if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) )
+        return( SSL_CERTIFICATE_SKIP );
+
+#if defined(MBEDTLS_SSL_SRV_C)
+    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
+    {
+        if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
+            return( SSL_CERTIFICATE_SKIP );
+
+        if( authmode == MBEDTLS_SSL_VERIFY_NONE )
+        {
+            ssl->session_negotiate->verify_result =
+                MBEDTLS_X509_BADCERT_SKIP_VERIFY;
+            return( SSL_CERTIFICATE_SKIP );
+        }
+    }
+#else
+    ((void) authmode);
+#endif /* MBEDTLS_SSL_SRV_C */
+
+    return( SSL_CERTIFICATE_EXPECTED );
+}
+
+static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl,
+                                         int authmode,
+                                         mbedtls_x509_crt *chain,
+                                         void *rs_ctx )
+{
+    int ret = 0;
+    const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+        ssl->transform_negotiate->ciphersuite_info;
+    mbedtls_x509_crt *ca_chain;
+    mbedtls_x509_crl *ca_crl;
+
+    if( authmode == MBEDTLS_SSL_VERIFY_NONE )
+        return( 0 );
+
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+    if( ssl->handshake->sni_ca_chain != NULL )
+    {
+        ca_chain = ssl->handshake->sni_ca_chain;
+        ca_crl   = ssl->handshake->sni_ca_crl;
+    }
+    else
+#endif
+    {
+        ca_chain = ssl->conf->ca_chain;
+        ca_crl   = ssl->conf->ca_crl;
+    }
+
+    /*
+     * Main check: verify certificate
+     */
+    ret = mbedtls_x509_crt_verify_restartable(
+        chain,
+        ca_chain, ca_crl,
+        ssl->conf->cert_profile,
+        ssl->hostname,
+        &ssl->session_negotiate->verify_result,
+        ssl->conf->f_vrfy, ssl->conf->p_vrfy, rs_ctx );
+
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
+    }
+
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+    if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
+        return( MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS );
+#endif
+
+    /*
+     * Secondary checks: always done, but change 'ret' only if it was 0
+     */
+
+#if defined(MBEDTLS_ECP_C)
+    {
+        const mbedtls_pk_context *pk = &chain->pk;
+
+        /* If certificate uses an EC key, make sure the curve is OK */
+        if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) &&
+            mbedtls_ssl_check_curve( ssl, mbedtls_pk_ec( *pk )->grp.id ) != 0 )
+        {
+            ssl->session_negotiate->verify_result |= MBEDTLS_X509_BADCERT_BAD_KEY;
+
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (EC key curve)" ) );
+            if( ret == 0 )
+                ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
+        }
+    }
+#endif /* MBEDTLS_ECP_C */
+
+    if( mbedtls_ssl_check_cert_usage( chain,
+                                      ciphersuite_info,
+                                      ! ssl->conf->endpoint,
+                                      &ssl->session_negotiate->verify_result ) != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (usage extensions)" ) );
+        if( ret == 0 )
+            ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
+    }
+
+    /* mbedtls_x509_crt_verify_with_profile is supposed to report a
+     * verification failure through MBEDTLS_ERR_X509_CERT_VERIFY_FAILED,
+     * with details encoded in the verification flags. All other kinds
+     * of error codes, including those from the user provided f_vrfy
+     * functions, are treated as fatal and lead to a failure of
+     * ssl_parse_certificate even if verification was optional. */
+    if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL &&
+        ( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED ||
+          ret == MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ) )
+    {
+        ret = 0;
+    }
+
+    if( ca_chain == NULL && authmode == MBEDTLS_SSL_VERIFY_REQUIRED )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no CA chain" ) );
+        ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED;
+    }
+
+    if( ret != 0 )
+    {
+        uint8_t alert;
+
+        /* The certificate may have been rejected for several reasons.
+           Pick one and send the corresponding alert. Which alert to send
+           may be a subject of debate in some cases. */
+        if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_OTHER )
+            alert = MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_CN_MISMATCH )
+            alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_KEY_USAGE )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXT_KEY_USAGE )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NS_CERT_TYPE )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_PK )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_KEY )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXPIRED )
+            alert = MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_REVOKED )
+            alert = MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED;
+        else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NOT_TRUSTED )
+            alert = MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA;
+        else
+            alert = MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN;
+        mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                        alert );
+    }
+
+#if defined(MBEDTLS_DEBUG_C)
+    if( ssl->session_negotiate->verify_result != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %x",
+                                    ssl->session_negotiate->verify_result ) );
+    }
+    else
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) );
+    }
+#endif /* MBEDTLS_DEBUG_C */
+
+    return( ret );
+}
+
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+static int ssl_remember_peer_crt_digest( mbedtls_ssl_context *ssl,
+                                         unsigned char *start, size_t len )
 {
     int ret;
-    const mbedtls_ssl_ciphersuite_t * const ciphersuite_info =
-          ssl->transform_negotiate->ciphersuite_info;
+    /* Remember digest of the peer's end-CRT. */
+    ssl->session_negotiate->peer_cert_digest =
+        mbedtls_calloc( 1, MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN );
+    if( ssl->session_negotiate->peer_cert_digest == NULL )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
+                                    sizeof( MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN ) ) );
+        mbedtls_ssl_send_alert_message( ssl,
+                                        MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                        MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
+
+        return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+    }
+
+    ret = mbedtls_md( mbedtls_md_info_from_type(
+                          MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE ),
+                      start, len,
+                      ssl->session_negotiate->peer_cert_digest );
+
+    ssl->session_negotiate->peer_cert_digest_type =
+        MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE;
+    ssl->session_negotiate->peer_cert_digest_len =
+        MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN;
+
+    return( ret );
+}
+
+static int ssl_remember_peer_pubkey( mbedtls_ssl_context *ssl,
+                                     unsigned char *start, size_t len )
+{
+    unsigned char *end = start + len;
+    int ret;
+
+    /* Make a copy of the peer's raw public key. */
+    mbedtls_pk_init( &ssl->handshake->peer_pubkey );
+    ret = mbedtls_pk_parse_subpubkey( &start, end,
+                                      &ssl->handshake->peer_pubkey );
+    if( ret != 0 )
+    {
+        /* We should have parsed the public key before. */
+        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+    }
+
+    return( 0 );
+}
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
+int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
+{
+    int ret = 0;
+    int crt_expected;
 #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
     const int authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET
                        ? ssl->handshake->sni_authmode
@@ -5814,43 +6237,23 @@ int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
     const int authmode = ssl->conf->authmode;
 #endif
     void *rs_ctx = NULL;
+    mbedtls_x509_crt *chain = NULL;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
 
-    if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+    crt_expected = ssl_parse_certificate_coordinate( ssl, authmode );
+    if( crt_expected == SSL_CERTIFICATE_SKIP )
     {
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
-        ssl->state++;
-        return( 0 );
+        goto exit;
     }
 
-#if defined(MBEDTLS_SSL_SRV_C)
-    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
-        ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
-        ssl->state++;
-        return( 0 );
-    }
-
-    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
-        authmode == MBEDTLS_SSL_VERIFY_NONE )
-    {
-        ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY;
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
-
-        ssl->state++;
-        return( 0 );
-    }
-#endif
-
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
     if( ssl->handshake->ecrs_enabled &&
         ssl->handshake->ecrs_state == ssl_ecrs_crt_verify )
     {
+        chain = ssl->handshake->ecrs_peer_cert;
+        ssl->handshake->ecrs_peer_cert = NULL;
         goto crt_verify;
     }
 #endif
@@ -5860,22 +6263,44 @@ int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
         /* mbedtls_ssl_read_record may have sent an alert already. We
            let it decide whether to alert. */
         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
-        return( ret );
+        goto exit;
     }
 
-    if( ( ret = ssl_parse_certificate_chain( ssl ) ) != 0 )
-    {
 #if defined(MBEDTLS_SSL_SRV_C)
-        if( ret == MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE &&
-            authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
-        {
-            ret = 0;
-        }
-#endif
+    if( ssl_srv_check_client_no_crt_notification( ssl ) == 0 )
+    {
+        ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
 
-        ssl->state++;
-        return( ret );
+        if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
+            ret = 0;
+        else
+            ret = MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE;
+
+        goto exit;
     }
+#endif /* MBEDTLS_SSL_SRV_C */
+
+    /* Clear existing peer CRT structure in case we tried to
+     * reuse a session but it failed, and allocate a new one. */
+    ssl_clear_peer_cert( ssl->session_negotiate );
+
+    chain = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
+    if( chain == NULL )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
+                                    sizeof( mbedtls_x509_crt ) ) );
+        mbedtls_ssl_send_alert_message( ssl,
+                                        MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                        MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
+
+        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        goto exit;
+    }
+    mbedtls_x509_crt_init( chain );
+
+    ret = ssl_parse_certificate_chain( ssl, chain );
+    if( ret != 0 )
+        goto exit;
 
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
     if( ssl->handshake->ecrs_enabled)
@@ -5886,154 +6311,71 @@ crt_verify:
         rs_ctx = &ssl->handshake->ecrs_ctx;
 #endif
 
-    if( authmode != MBEDTLS_SSL_VERIFY_NONE )
+    ret = ssl_parse_certificate_verify( ssl, authmode,
+                                        chain, rs_ctx );
+    if( ret != 0 )
+        goto exit;
+
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     {
-        mbedtls_x509_crt *ca_chain;
-        mbedtls_x509_crl *ca_crl;
+        unsigned char *crt_start, *pk_start;
+        size_t crt_len, pk_len;
 
-#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
-        if( ssl->handshake->sni_ca_chain != NULL )
-        {
-            ca_chain = ssl->handshake->sni_ca_chain;
-            ca_crl   = ssl->handshake->sni_ca_crl;
-        }
-        else
-#endif
-        {
-            ca_chain = ssl->conf->ca_chain;
-            ca_crl   = ssl->conf->ca_crl;
-        }
+        /* We parse the CRT chain without copying, so
+         * these pointers point into the input buffer,
+         * and are hence still valid after freeing the
+         * CRT chain. */
 
-        /*
-         * Main check: verify certificate
-         */
-        ret = mbedtls_x509_crt_verify_restartable(
-                                ssl->session_negotiate->peer_cert,
-                                ca_chain, ca_crl,
-                                ssl->conf->cert_profile,
-                                ssl->hostname,
-                               &ssl->session_negotiate->verify_result,
-                                ssl->conf->f_vrfy, ssl->conf->p_vrfy, rs_ctx );
+        crt_start = chain->raw.p;
+        crt_len   = chain->raw.len;
 
+        pk_start = chain->pk_raw.p;
+        pk_len   = chain->pk_raw.len;
+
+        /* Free the CRT structures before computing
+         * digest and copying the peer's public key. */
+        mbedtls_x509_crt_free( chain );
+        mbedtls_free( chain );
+        chain = NULL;
+
+        ret = ssl_remember_peer_crt_digest( ssl, crt_start, crt_len );
         if( ret != 0 )
-        {
-            MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
-        }
-
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
-        if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
-            return( MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS );
-#endif
-
-        /*
-         * Secondary checks: always done, but change 'ret' only if it was 0
-         */
-
-#if defined(MBEDTLS_ECP_C)
-        {
-            const mbedtls_pk_context *pk = &ssl->session_negotiate->peer_cert->pk;
-
-            /* If certificate uses an EC key, make sure the curve is OK */
-            if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) &&
-                mbedtls_ssl_check_curve( ssl, mbedtls_pk_ec( *pk )->grp.id ) != 0 )
-            {
-                ssl->session_negotiate->verify_result |= MBEDTLS_X509_BADCERT_BAD_KEY;
-
-                MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (EC key curve)" ) );
-                if( ret == 0 )
-                    ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
-            }
-        }
-#endif /* MBEDTLS_ECP_C */
-
-        if( mbedtls_ssl_check_cert_usage( ssl->session_negotiate->peer_cert,
-                                 ciphersuite_info,
-                                 ! ssl->conf->endpoint,
-                                 &ssl->session_negotiate->verify_result ) != 0 )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (usage extensions)" ) );
-            if( ret == 0 )
-                ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
-        }
-
-        /* mbedtls_x509_crt_verify_with_profile is supposed to report a
-         * verification failure through MBEDTLS_ERR_X509_CERT_VERIFY_FAILED,
-         * with details encoded in the verification flags. All other kinds
-         * of error codes, including those from the user provided f_vrfy
-         * functions, are treated as fatal and lead to a failure of
-         * ssl_parse_certificate even if verification was optional. */
-        if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL &&
-            ( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED ||
-              ret == MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ) )
-        {
-            ret = 0;
-        }
-
-        if( ca_chain == NULL && authmode == MBEDTLS_SSL_VERIFY_REQUIRED )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no CA chain" ) );
-            ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED;
-        }
+            goto exit;
 
+        ret = ssl_remember_peer_pubkey( ssl, pk_start, pk_len );
         if( ret != 0 )
-        {
-            uint8_t alert;
-
-            /* The certificate may have been rejected for several reasons.
-               Pick one and send the corresponding alert. Which alert to send
-               may be a subject of debate in some cases. */
-            if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_OTHER )
-                alert = MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_CN_MISMATCH )
-                alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_KEY_USAGE )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXT_KEY_USAGE )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NS_CERT_TYPE )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_PK )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_KEY )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXPIRED )
-                alert = MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_REVOKED )
-                alert = MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED;
-            else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NOT_TRUSTED )
-                alert = MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA;
-            else
-                alert = MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN;
-            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                            alert );
-        }
-
-#if defined(MBEDTLS_DEBUG_C)
-        if( ssl->session_negotiate->verify_result != 0 )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %x",
-                                        ssl->session_negotiate->verify_result ) );
-        }
-        else
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) );
-        }
-#endif /* MBEDTLS_DEBUG_C */
+            goto exit;
     }
-
-    ssl->state++;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+    /* Pass ownership to session structure. */
+    ssl->session_negotiate->peer_cert = chain;
+    chain = NULL;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
 
+exit:
+
+    if( ret == 0 )
+        ssl->state++;
+
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+    if( ret == MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS )
+    {
+        ssl->handshake->ecrs_peer_cert = chain;
+        chain = NULL;
+    }
+#endif
+
+    if( chain != NULL )
+    {
+        mbedtls_x509_crt_free( chain );
+        mbedtls_free( chain );
+    }
+
     return( ret );
 }
-#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED
-          !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
 
 int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl )
 {
@@ -6169,11 +6511,21 @@ void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl )
 #endif
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_abort( &ssl->handshake->fin_sha256_psa );
+    psa_hash_setup( &ssl->handshake->fin_sha256_psa, PSA_ALG_SHA_256 );
+#else
     mbedtls_sha256_starts_ret( &ssl->handshake->fin_sha256, 0 );
 #endif
+#endif
 #if defined(MBEDTLS_SHA512_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_abort( &ssl->handshake->fin_sha384_psa );
+    psa_hash_setup( &ssl->handshake->fin_sha384_psa, PSA_ALG_SHA_384 );
+#else
     mbedtls_sha512_starts_ret( &ssl->handshake->fin_sha512, 1 );
 #endif
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 }
 
@@ -6187,11 +6539,19 @@ static void ssl_update_checksum_start( mbedtls_ssl_context *ssl,
 #endif
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_update( &ssl->handshake->fin_sha256_psa, buf, len );
+#else
     mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len );
 #endif
+#endif
 #if defined(MBEDTLS_SHA512_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_update( &ssl->handshake->fin_sha384_psa, buf, len );
+#else
     mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len );
 #endif
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 }
 
@@ -6210,7 +6570,11 @@ static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *ssl,
 static void ssl_update_checksum_sha256( mbedtls_ssl_context *ssl,
                                         const unsigned char *buf, size_t len )
 {
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_update( &ssl->handshake->fin_sha256_psa, buf, len );
+#else
     mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len );
+#endif
 }
 #endif
 
@@ -6218,7 +6582,11 @@ static void ssl_update_checksum_sha256( mbedtls_ssl_context *ssl,
 static void ssl_update_checksum_sha384( mbedtls_ssl_context *ssl,
                                         const unsigned char *buf, size_t len )
 {
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_update( &ssl->handshake->fin_sha384_psa, buf, len );
+#else
     mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len );
+#endif
 }
 #endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
@@ -6374,13 +6742,44 @@ static void ssl_calc_finished_tls_sha256(
 {
     int len = 12;
     const char *sender;
-    mbedtls_sha256_context sha256;
     unsigned char padbuf[32];
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    size_t hash_size;
+    psa_hash_operation_t sha256_psa = PSA_HASH_OPERATION_INIT;
+    psa_status_t status;
+#else
+    mbedtls_sha256_context sha256;
+#endif
 
     mbedtls_ssl_session *session = ssl->session_negotiate;
     if( !session )
         session = ssl->session;
 
+    sender = ( from == MBEDTLS_SSL_IS_CLIENT )
+             ? "client finished"
+             : "server finished";
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    sha256_psa = psa_hash_operation_init();
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc PSA finished tls sha256" ) );
+
+    status = psa_hash_clone( &ssl->handshake->fin_sha256_psa, &sha256_psa );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash clone failed" ) );
+        return;
+    }
+
+    status = psa_hash_finish( &sha256_psa, padbuf, sizeof( padbuf ), &hash_size );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash finish failed" ) );
+        return;
+    }
+    MBEDTLS_SSL_DEBUG_BUF( 3, "PSA calculated padbuf", padbuf, 32 );
+#else
+
     mbedtls_sha256_init( &sha256 );
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc  finished tls sha256" ) );
@@ -6398,19 +6797,15 @@ static void ssl_calc_finished_tls_sha256(
                    sha256.state, sizeof( sha256.state ) );
 #endif
 
-    sender = ( from == MBEDTLS_SSL_IS_CLIENT )
-             ? "client finished"
-             : "server finished";
-
     mbedtls_sha256_finish_ret( &sha256, padbuf );
+    mbedtls_sha256_free( &sha256 );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
 
     ssl->handshake->tls_prf( session->master, 48, sender,
                              padbuf, 32, buf, len );
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
 
-    mbedtls_sha256_free( &sha256 );
-
     mbedtls_platform_zeroize(  padbuf, sizeof(  padbuf ) );
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc  finished" ) );
@@ -6423,13 +6818,43 @@ static void ssl_calc_finished_tls_sha384(
 {
     int len = 12;
     const char *sender;
-    mbedtls_sha512_context sha512;
     unsigned char padbuf[48];
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    size_t hash_size;
+    psa_hash_operation_t sha384_psa = PSA_HASH_OPERATION_INIT;
+    psa_status_t status;
+#else
+    mbedtls_sha512_context sha512;
+#endif
 
     mbedtls_ssl_session *session = ssl->session_negotiate;
     if( !session )
         session = ssl->session;
 
+    sender = ( from == MBEDTLS_SSL_IS_CLIENT )
+                ? "client finished"
+                : "server finished";
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    sha384_psa = psa_hash_operation_init();
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc PSA finished tls sha384" ) );
+
+    status = psa_hash_clone( &ssl->handshake->fin_sha384_psa, &sha384_psa );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash clone failed" ) );
+        return;
+    }
+
+    status = psa_hash_finish( &sha384_psa, padbuf, sizeof( padbuf ), &hash_size );
+    if( status != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "PSA hash finish failed" ) );
+        return;
+    }
+    MBEDTLS_SSL_DEBUG_BUF( 3, "PSA calculated padbuf", padbuf, 48 );
+#else
     mbedtls_sha512_init( &sha512 );
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc  finished tls sha384" ) );
@@ -6447,19 +6872,15 @@ static void ssl_calc_finished_tls_sha384(
                    sha512.state, sizeof( sha512.state ) );
 #endif
 
-    sender = ( from == MBEDTLS_SSL_IS_CLIENT )
-             ? "client finished"
-             : "server finished";
-
     mbedtls_sha512_finish_ret( &sha512, padbuf );
+    mbedtls_sha512_free( &sha512 );
+#endif
 
     ssl->handshake->tls_prf( session->master, 48, sender,
                              padbuf, 48, buf, len );
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
 
-    mbedtls_sha512_free( &sha512 );
-
     mbedtls_platform_zeroize(  padbuf, sizeof( padbuf ) );
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc  finished" ) );
@@ -6770,13 +7191,23 @@ static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake )
 #endif
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    handshake->fin_sha256_psa = psa_hash_operation_init();
+    psa_hash_setup( &handshake->fin_sha256_psa, PSA_ALG_SHA_256 );
+#else
     mbedtls_sha256_init(   &handshake->fin_sha256    );
     mbedtls_sha256_starts_ret( &handshake->fin_sha256, 0 );
 #endif
+#endif
 #if defined(MBEDTLS_SHA512_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    handshake->fin_sha384_psa = psa_hash_operation_init();
+    psa_hash_setup( &handshake->fin_sha384_psa, PSA_ALG_SHA_384 );
+#else
     mbedtls_sha512_init(   &handshake->fin_sha512    );
     mbedtls_sha512_starts_ret( &handshake->fin_sha512, 1 );
 #endif
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
     handshake->update_checksum = ssl_update_checksum_start;
@@ -6807,6 +7238,11 @@ static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake )
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
     handshake->sni_authmode = MBEDTLS_SSL_VERIFY_UNSET;
 #endif
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    mbedtls_pk_init( &handshake->peer_pubkey );
+#endif
 }
 
 static void ssl_transform_init( mbedtls_ssl_transform *transform )
@@ -7356,7 +7792,8 @@ int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
     }
 
-    if( ( ret = ssl_session_copy( ssl->session_negotiate, session ) ) != 0 )
+    if( ( ret = mbedtls_ssl_session_copy( ssl->session_negotiate,
+                                          session ) ) != 0 )
         return( ret );
 
     ssl->handshake->resume = 1;
@@ -7617,7 +8054,7 @@ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 int mbedtls_ssl_conf_psk_opaque( mbedtls_ssl_config *conf,
-                                 psa_key_slot_t psk_slot,
+                                 psa_key_handle_t psk_slot,
                                  const unsigned char *psk_identity,
                                  size_t psk_identity_len )
 {
@@ -7640,7 +8077,7 @@ int mbedtls_ssl_conf_psk_opaque( mbedtls_ssl_config *conf,
 }
 
 int mbedtls_ssl_set_hs_psk_opaque( mbedtls_ssl_context *ssl,
-                                   psa_key_slot_t psk_slot )
+                                   psa_key_handle_t psk_slot )
 {
     if( psk_slot == 0 || ssl->handshake == NULL )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
@@ -8275,12 +8712,17 @@ const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ss
     if( ssl == NULL || ssl->session == NULL )
         return( NULL );
 
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     return( ssl->session->peer_cert );
+#else
+    return( NULL );
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 }
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_SSL_CLI_C)
-int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *dst )
+int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl,
+                             mbedtls_ssl_session *dst )
 {
     if( ssl == NULL ||
         dst == NULL ||
@@ -8290,7 +8732,7 @@ int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
     }
 
-    return( ssl_session_copy( dst, ssl->session ) );
+    return( mbedtls_ssl_session_copy( dst, ssl->session ) );
 }
 #endif /* MBEDTLS_SSL_CLI_C */
 
@@ -9079,11 +9521,19 @@ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl )
 #endif
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_abort( &handshake->fin_sha256_psa );
+#else
     mbedtls_sha256_free(   &handshake->fin_sha256    );
 #endif
+#endif
 #if defined(MBEDTLS_SHA512_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_hash_abort( &handshake->fin_sha384_psa );
+#else
     mbedtls_sha512_free(   &handshake->fin_sha512    );
 #endif
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
 #if defined(MBEDTLS_DHM_C)
@@ -9136,14 +9586,29 @@ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl )
 
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
     mbedtls_x509_crt_restart_free( &handshake->ecrs_ctx );
+    if( handshake->ecrs_peer_cert != NULL )
+    {
+        mbedtls_x509_crt_free( handshake->ecrs_peer_cert );
+        mbedtls_free( handshake->ecrs_peer_cert );
+    }
 #endif
 
+#if defined(MBEDTLS_X509_CRT_PARSE_C) &&        \
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    mbedtls_pk_free( &handshake->peer_pubkey );
+#endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     mbedtls_free( handshake->verify_cookie );
     ssl_flight_free( handshake->flight );
     ssl_buffering_free( ssl );
 #endif
 
+#if defined(MBEDTLS_ECDH_C) &&                  \
+    defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_destroy_key( handshake->ecdh_psa_privkey );
+#endif /* MBEDTLS_ECDH_C && MBEDTLS_USE_PSA_CRYPTO */
+
     mbedtls_platform_zeroize( handshake,
                               sizeof( mbedtls_ssl_handshake_params ) );
 }
@@ -9154,11 +9619,7 @@ void mbedtls_ssl_session_free( mbedtls_ssl_session *session )
         return;
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
-    if( session->peer_cert != NULL )
-    {
-        mbedtls_x509_crt_free( session->peer_cert );
-        mbedtls_free( session->peer_cert );
-    }
+    ssl_clear_peer_cert( session );
 #endif
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
@@ -9972,6 +10433,70 @@ exit:
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
     defined(MBEDTLS_SSL_PROTO_TLS1_2)
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
+                                            unsigned char *hash, size_t *hashlen,
+                                            unsigned char *data, size_t data_len,
+                                            mbedtls_md_type_t md_alg )
+{
+    psa_status_t status;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
+    psa_algorithm_t hash_alg = mbedtls_psa_translate_md( md_alg );
+
+    MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based computation of digest of ServerKeyExchange" ) );
+
+    if( ( status = psa_hash_setup( &hash_operation,
+                                   hash_alg ) ) != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "psa_hash_setup", status );
+        goto exit;
+    }
+
+    if( ( status = psa_hash_update( &hash_operation, ssl->handshake->randbytes,
+                                    64 ) ) != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "psa_hash_update", status );
+        goto exit;
+    }
+
+    if( ( status = psa_hash_update( &hash_operation,
+                                    data, data_len ) ) != PSA_SUCCESS )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "psa_hash_update", status );
+        goto exit;
+    }
+
+    if( ( status = psa_hash_finish( &hash_operation, hash, MBEDTLS_MD_MAX_SIZE,
+                                    hashlen ) ) != PSA_SUCCESS )
+    {
+         MBEDTLS_SSL_DEBUG_RET( 1, "psa_hash_finish", status );
+         goto exit;
+    }
+
+exit:
+    if( status != PSA_SUCCESS )
+    {
+        mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                        MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
+        switch( status )
+        {
+            case PSA_ERROR_NOT_SUPPORTED:
+                return( MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE );
+            case PSA_ERROR_BAD_STATE: /* Intentional fallthrough */
+            case PSA_ERROR_BUFFER_TOO_SMALL:
+                return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
+            case PSA_ERROR_INSUFFICIENT_MEMORY:
+                return( MBEDTLS_ERR_MD_ALLOC_FAILED );
+            default:
+                return( MBEDTLS_ERR_MD_HW_ACCEL_FAILED );
+        }
+    }
+    return( 0 );
+}
+
+#else
+
 int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
                                             unsigned char *hash, size_t *hashlen,
                                             unsigned char *data, size_t data_len,
@@ -9982,6 +10507,8 @@ int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
     const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
     *hashlen = mbedtls_md_get_size( md_info );
 
+    MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform mbedtls-based computation of digest of ServerKeyExchange" ) );
+
     mbedtls_md_init( &ctx );
 
     /*
@@ -10026,6 +10553,8 @@ exit:
 
     return( ret );
 }
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
           MBEDTLS_SSL_PROTO_TLS1_2 */
 
diff --git a/features/mbedtls/src/version_features.c b/features/mbedtls/src/version_features.c
index e2e9949062..161788ca76 100644
--- a/features/mbedtls/src/version_features.c
+++ b/features/mbedtls/src/version_features.c
@@ -72,6 +72,9 @@ static const char *features[] = {
 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
     "MBEDTLS_PLATFORM_SNPRINTF_ALT",
 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
+#if defined(MBEDTLS_PLATFORM_VSNPRINTF_ALT)
+    "MBEDTLS_PLATFORM_VSNPRINTF_ALT",
+#endif /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
 #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
     "MBEDTLS_PLATFORM_NV_SEED_ALT",
 #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
@@ -84,6 +87,9 @@ static const char *features[] = {
 #if defined(MBEDTLS_DEPRECATED_REMOVED)
     "MBEDTLS_DEPRECATED_REMOVED",
 #endif /* MBEDTLS_DEPRECATED_REMOVED */
+#if defined(MBEDTLS_CHECK_PARAMS)
+    "MBEDTLS_CHECK_PARAMS",
+#endif /* MBEDTLS_CHECK_PARAMS */
 #if defined(MBEDTLS_TIMING_ALT)
     "MBEDTLS_TIMING_ALT",
 #endif /* MBEDTLS_TIMING_ALT */
@@ -297,6 +303,9 @@ static const char *features[] = {
 #if defined(MBEDTLS_REMOVE_ARC4_CIPHERSUITES)
     "MBEDTLS_REMOVE_ARC4_CIPHERSUITES",
 #endif /* MBEDTLS_REMOVE_ARC4_CIPHERSUITES */
+#if defined(MBEDTLS_REMOVE_3DES_CIPHERSUITES)
+    "MBEDTLS_REMOVE_3DES_CIPHERSUITES",
+#endif /* MBEDTLS_REMOVE_3DES_CIPHERSUITES */
 #if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
     "MBEDTLS_ECP_DP_SECP192R1_ENABLED",
 #endif /* MBEDTLS_ECP_DP_SECP192R1_ENABLED */
@@ -417,6 +426,12 @@ static const char *features[] = {
 #if defined(MBEDTLS_PKCS1_V21)
     "MBEDTLS_PKCS1_V21",
 #endif /* MBEDTLS_PKCS1_V21 */
+#if defined(MBEDTLS_PSA_CRYPTO_SPM)
+    "MBEDTLS_PSA_CRYPTO_SPM",
+#endif /* MBEDTLS_PSA_CRYPTO_SPM */
+#if defined(MBEDTLS_PSA_HAS_ITS_IO)
+    "MBEDTLS_PSA_HAS_ITS_IO",
+#endif /* MBEDTLS_PSA_HAS_ITS_IO */
 #if defined(MBEDTLS_RSA_NO_CRT)
     "MBEDTLS_RSA_NO_CRT",
 #endif /* MBEDTLS_RSA_NO_CRT */
@@ -444,6 +459,9 @@ static const char *features[] = {
 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
     "MBEDTLS_SSL_FALLBACK_SCSV",
 #endif /* MBEDTLS_SSL_FALLBACK_SCSV */
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+    "MBEDTLS_SSL_KEEP_PEER_CERTIFICATE",
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
     "MBEDTLS_SSL_HW_RECORD_ACCEL",
 #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
@@ -687,6 +705,15 @@ static const char *features[] = {
 #if defined(MBEDTLS_PSA_CRYPTO_C)
     "MBEDTLS_PSA_CRYPTO_C",
 #endif /* MBEDTLS_PSA_CRYPTO_C */
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
+    "MBEDTLS_PSA_CRYPTO_STORAGE_C",
+#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C */
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C)
+    "MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C",
+#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C */
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C)
+    "MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C",
+#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C */
 #if defined(MBEDTLS_RIPEMD160_C)
     "MBEDTLS_RIPEMD160_C",
 #endif /* MBEDTLS_RIPEMD160_C */
diff --git a/features/mbedtls/src/x509.c b/features/mbedtls/src/x509.c
index 52b5b649f7..6b7899fe0c 100644
--- a/features/mbedtls/src/x509.c
+++ b/features/mbedtls/src/x509.c
@@ -116,7 +116,7 @@ int mbedtls_x509_get_alg_null( unsigned char **p, const unsigned char *end,
 }
 
 /*
- * Parse an algorithm identifier with (optional) paramaters
+ * Parse an algorithm identifier with (optional) parameters
  */
 int mbedtls_x509_get_alg( unsigned char **p, const unsigned char *end,
                   mbedtls_x509_buf *alg, mbedtls_x509_buf *params )
diff --git a/features/mbedtls/src/x509_crt.c b/features/mbedtls/src/x509_crt.c
index c5b6a12489..5d82816f2b 100644
--- a/features/mbedtls/src/x509_crt.c
+++ b/features/mbedtls/src/x509_crt.c
@@ -373,7 +373,7 @@ static void x509_crt_verify_chain_reset(
     for( i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++ )
     {
         ver_chain->items[i].crt = NULL;
-        ver_chain->items[i].flags = -1;
+        ver_chain->items[i].flags = (uint32_t) -1;
     }
 
     ver_chain->len = 0;
@@ -834,8 +834,10 @@ static int x509_get_crt_ext( unsigned char **p,
 /*
  * Parse and fill a single X.509 certificate in DER format
  */
-static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf,
-                                    size_t buflen )
+static int x509_crt_parse_der_core( mbedtls_x509_crt *crt,
+                                    const unsigned char *buf,
+                                    size_t buflen,
+                                    int make_copy )
 {
     int ret;
     size_t len;
@@ -852,7 +854,7 @@ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *
     if( crt == NULL || buf == NULL )
         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
 
-    // Use the original buffer until we figure out actual length
+    /* Use the original buffer until we figure out actual length. */
     p = (unsigned char*) buf;
     len = buflen;
     end = p + len;
@@ -870,25 +872,26 @@ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *
         return( MBEDTLS_ERR_X509_INVALID_FORMAT );
     }
 
-    if( len > (size_t) ( end - p ) )
-    {
-        mbedtls_x509_crt_free( crt );
-        return( MBEDTLS_ERR_X509_INVALID_FORMAT +
-                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
-    }
-    crt_end = p + len;
-
-    // Create and populate a new buffer for the raw field
-    crt->raw.len = crt_end - buf;
-    crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
-    if( p == NULL )
-        return( MBEDTLS_ERR_X509_ALLOC_FAILED );
-
-    memcpy( p, buf, crt->raw.len );
-
-    // Direct pointers to the new buffer
-    p += crt->raw.len - len;
     end = crt_end = p + len;
+    crt->raw.len = crt_end - buf;
+    if( make_copy != 0 )
+    {
+        /* Create and populate a new buffer for the raw field. */
+        crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
+        if( crt->raw.p == NULL )
+            return( MBEDTLS_ERR_X509_ALLOC_FAILED );
+
+        memcpy( crt->raw.p, buf, crt->raw.len );
+        crt->own_buffer = 1;
+
+        p += crt->raw.len - len;
+        end = crt_end = p + len;
+    }
+    else
+    {
+        crt->raw.p = (unsigned char*) buf;
+        crt->own_buffer = 0;
+    }
 
     /*
      * TBSCertificate  ::=  SEQUENCE  {
@@ -993,11 +996,13 @@ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *
     /*
      * SubjectPublicKeyInfo
      */
+    crt->pk_raw.p = p;
     if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
     {
         mbedtls_x509_crt_free( crt );
         return( ret );
     }
+    crt->pk_raw.len = p - crt->pk_raw.p;
 
     /*
      *  issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
@@ -1091,8 +1096,10 @@ static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *
  * Parse one X.509 certificate in DER format from a buffer and add them to a
  * chained list
  */
-int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
-                        size_t buflen )
+static int mbedtls_x509_crt_parse_der_internal( mbedtls_x509_crt *chain,
+                                                const unsigned char *buf,
+                                                size_t buflen,
+                                                int make_copy )
 {
     int ret;
     mbedtls_x509_crt *crt = chain, *prev = NULL;
@@ -1124,7 +1131,7 @@ int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *bu
         crt = crt->next;
     }
 
-    if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
+    if( ( ret = x509_crt_parse_der_core( crt, buf, buflen, make_copy ) ) != 0 )
     {
         if( prev )
             prev->next = NULL;
@@ -1138,11 +1145,27 @@ int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *bu
     return( 0 );
 }
 
+int mbedtls_x509_crt_parse_der_nocopy( mbedtls_x509_crt *chain,
+                                       const unsigned char *buf,
+                                       size_t buflen )
+{
+    return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 0 ) );
+}
+
+int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain,
+                                const unsigned char *buf,
+                                size_t buflen )
+{
+    return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 1 ) );
+}
+
 /*
  * Parse one or more PEM certificates from a buffer and add them to the chained
  * list
  */
-int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen )
+int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain,
+                            const unsigned char *buf,
+                            size_t buflen )
 {
 #if defined(MBEDTLS_PEM_PARSE_C)
     int success = 0, first_error = 0, total_failed = 0;
@@ -1908,7 +1931,7 @@ static int x509_crt_check_signature( const mbedtls_x509_crt *child,
     if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
         return( -1 );
 #else
-    psa_hash_operation_t hash_operation;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( child->sig_md );
 
     if( psa_hash_setup( &hash_operation, hash_alg ) != PSA_SUCCESS )
@@ -2203,7 +2226,7 @@ static int x509_crt_find_parent(
     }
 
     /* extra precaution against mistakes in the caller */
-    if( parent == NULL )
+    if( *parent == NULL )
     {
         *parent_is_trusted = 0;
         *signature_is_good = 0;
@@ -2261,7 +2284,7 @@ static int x509_crt_check_ee_locally_trusted(
  * Tests for (aspects of) this function should include at least:
  * - trusted EE
  * - EE -> trusted root
- * - EE -> intermedate CA -> trusted root
+ * - EE -> intermediate CA -> trusted root
  * - if relevant: EE untrusted
  * - if relevant: EE -> intermediate, untrusted
  * with the aspect under test checked at each relevant level (EE, int, root).
@@ -2699,7 +2722,7 @@ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
             mbedtls_free( seq_prv );
         }
 
-        if( cert_cur->raw.p != NULL )
+        if( cert_cur->raw.p != NULL && cert_cur->own_buffer )
         {
             mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
             mbedtls_free( cert_cur->raw.p );
diff --git a/features/mbedtls/src/x509_csr.c b/features/mbedtls/src/x509_csr.c
index f84425728a..c8c08c87b2 100644
--- a/features/mbedtls/src/x509_csr.c
+++ b/features/mbedtls/src/x509_csr.c
@@ -279,15 +279,24 @@ int mbedtls_x509_csr_parse( mbedtls_x509_csr *csr, const unsigned char *buf, siz
     {
         mbedtls_pem_init( &pem );
         ret = mbedtls_pem_read_buffer( &pem,
-                               "-----BEGIN CERTIFICATE REQUEST-----",
-                               "-----END CERTIFICATE REQUEST-----",
-                               buf, NULL, 0, &use_len );
+                                       "-----BEGIN CERTIFICATE REQUEST-----",
+                                       "-----END CERTIFICATE REQUEST-----",
+                                       buf, NULL, 0, &use_len );
+        if( ret == MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+        {
+            ret = mbedtls_pem_read_buffer( &pem,
+                                           "-----BEGIN NEW CERTIFICATE REQUEST-----",
+                                           "-----END NEW CERTIFICATE REQUEST-----",
+                                           buf, NULL, 0, &use_len );
+        }
 
         if( ret == 0 )
+        {
             /*
              * Was PEM encoded, parse the result
              */
             ret = mbedtls_x509_csr_parse_der( csr, pem.buf, pem.buflen );
+        }
 
         mbedtls_pem_free( &pem );
         if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
diff --git a/features/mbedtls/src/x509write_crt.c b/features/mbedtls/src/x509write_crt.c
index b1ef216c95..b6cb745a33 100644
--- a/features/mbedtls/src/x509write_crt.c
+++ b/features/mbedtls/src/x509write_crt.c
@@ -221,23 +221,36 @@ int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *
 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
                                          unsigned int key_usage )
 {
-    unsigned char buf[4], ku;
+    unsigned char buf[5], ku[2];
     unsigned char *c;
     int ret;
+    const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
+        MBEDTLS_X509_KU_NON_REPUDIATION   |
+        MBEDTLS_X509_KU_KEY_ENCIPHERMENT  |
+        MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
+        MBEDTLS_X509_KU_KEY_AGREEMENT     |
+        MBEDTLS_X509_KU_KEY_CERT_SIGN     |
+        MBEDTLS_X509_KU_CRL_SIGN          |
+        MBEDTLS_X509_KU_ENCIPHER_ONLY     |
+        MBEDTLS_X509_KU_DECIPHER_ONLY;
 
-    /* We currently only support 7 bits, from 0x80 to 0x02 */
-    if( ( key_usage & ~0xfe ) != 0 )
+    /* Check that nothing other than the allowed flags is set */
+    if( ( key_usage & ~allowed_bits ) != 0 )
         return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
 
-    c = buf + 4;
-    ku = (unsigned char) key_usage;
+    c = buf + 5;
+    ku[0] = (unsigned char)( key_usage      );
+    ku[1] = (unsigned char)( key_usage >> 8 );
+    ret = mbedtls_asn1_write_named_bitstring( &c, buf, ku, 9 );
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ku, 7 ) ) != 4 )
+    if( ret < 0 )
         return( ret );
+    else if( ret < 3 || ret > 5 )
+        return( MBEDTLS_ERR_X509_INVALID_FORMAT );
 
     ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
-                                       1, buf, 4 );
+                                       1, c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
@@ -253,12 +266,13 @@ int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
+    ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
+    if( ret < 3 || ret > 4 )
         return( ret );
 
     ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
-                                       0, buf, 4 );
+                                       0, c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
diff --git a/features/mbedtls/src/x509write_csr.c b/features/mbedtls/src/x509write_csr.c
index f2950ad2fa..8dc39e7a5a 100644
--- a/features/mbedtls/src/x509write_csr.c
+++ b/features/mbedtls/src/x509write_csr.c
@@ -94,12 +94,13 @@ int mbedtls_x509write_csr_set_key_usage( mbedtls_x509write_csr *ctx, unsigned ch
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
+    ret = mbedtls_asn1_write_named_bitstring( &c, buf, &key_usage, 8 );
+    if( ret < 3 || ret > 4 )
         return( ret );
 
     ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
-                                       buf, 4 );
+                                       c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
@@ -115,12 +116,13 @@ int mbedtls_x509write_csr_set_ns_cert_type( mbedtls_x509write_csr *ctx,
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
+    ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
+    if( ret < 3 || ret > 4 )
         return( ret );
 
     ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
-                                       buf, 4 );
+                                       c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
@@ -142,7 +144,7 @@ int mbedtls_x509write_csr_der( mbedtls_x509write_csr *ctx, unsigned char *buf, s
     size_t len = 0;
     mbedtls_pk_type_t pk_alg;
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    psa_hash_operation_t hash_operation;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
     size_t hash_len;
     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( ctx->md_alg );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */