BLE: Add LESC crypto toolbox for Nordic.

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5XCrypto.cpp

@@ -0,0 +1,140 @@
+#include <algorithm>
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+#include <stdio.h>
+#include <string.h>
+
+
+#include "mbedtls/platform.h"
+#include "mbedtls/ecdh.h"
+#include "mbedtls/memory_buffer_alloc.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ecp.h"
+
+#include "platform/NonCopyable.h"
+#include "platform/CriticalSectionLock.h"
+#include "ble/BLETypes.h"
+#include "cmsis.h"
+#include "nRF5xCrypto.h"
+
+namespace ble {
+namespace pal {
+namespace vendor {
+namespace nordic {
+
+LescCrypto::LescCrypto() : _initialized(false) {
+    mbedtls_entropy_init(&_entropy_context);
+    mbedtls_ecp_group_init(&_group);
+    int err = mbedtls_ecp_group_load(
+        &_group,
+        MBEDTLS_ECP_DP_SECP256R1
+    );
+    _initialized = err ? false : true;
+}
+
+LescCrypto::~LescCrypto() {
+    mbedtls_ecp_group_free(&_group);
+    mbedtls_entropy_free(&_entropy_context);
+}
+
+bool LescCrypto::generate_keys(
+    ble::public_key_coord_t& X,
+    ble::public_key_coord_t& Y,
+    ble::public_key_coord_t& secret
+) {
+    mbedtls_mpi secret_key;
+    mbedtls_ecp_point public_keys;
+
+    mbedtls_mpi_init(&secret_key);
+    mbedtls_ecp_point_init(&public_keys);
+
+    int err = mbedtls_ecp_gen_keypair(
+        &_group,
+        &secret_key,
+        &public_keys,
+        mbedtls_entropy_func,
+        &_entropy_context
+    );
+
+    if (!err) {
+        store_mpi(secret, secret_key);
+        store_mpi(X, public_keys.X);
+        store_mpi(Y, public_keys.Y);
+    }
+
+    mbedtls_ecp_point_free(&public_keys);
+    mbedtls_mpi_free(&secret_key);
+
+    return err ? false : true;
+}
+
+bool LescCrypto::generate_shared_secret(
+    const ble::public_key_coord_t& peer_X,
+    const ble::public_key_coord_t& peer_Y,
+    const ble::public_key_coord_t& own_secret,
+    ble::public_key_coord_t& shared_secret
+) {
+    mbedtls_mpi result;
+    mbedtls_mpi secret_key;
+    mbedtls_ecp_point public_keys;
+
+    mbedtls_mpi_init(&result);
+    mbedtls_mpi_init(&secret_key);
+    mbedtls_ecp_point_init(&public_keys);
+
+    load_mpi(secret_key, own_secret);
+    load_mpi(public_keys.X, peer_X);
+    load_mpi(public_keys.Y, peer_Y);
+    mbedtls_mpi_lset( &public_keys.Z, 1 );
+
+    int err = mbedtls_ecdh_compute_shared(
+        &_group,
+        &result,
+        &public_keys,
+        &secret_key,
+        /* rng function; optional */ NULL,
+        /* rng param */ NULL
+    );
+
+    if (!err) {
+        store_mpi(shared_secret, result);
+    }
+
+    mbedtls_ecp_point_free(&public_keys);
+    mbedtls_mpi_free(&secret_key);
+    mbedtls_mpi_free(&result);
+
+    return err ? false : true;
+}
+
+
+void LescCrypto::load_mpi(mbedtls_mpi& dest, const ble::public_key_coord_t& src) {
+    ble::public_key_coord_t src_be = src;
+    swap_endian(src_be);
+    mbedtls_mpi_read_binary(&dest, src_be.buffer(), src_be.size());
+}
+
+void LescCrypto::store_mpi(ble::public_key_coord_t& dest, const mbedtls_mpi& src) {
+    mbedtls_mpi_write_binary(&src, dest.buffer(), dest.size());
+    swap_endian(dest);
+}
+
+void LescCrypto::swap_endian(ble::public_key_coord_t& to_swap) {
+    swap_endian(to_swap.buffer(), to_swap.size());
+}
+
+void LescCrypto::swap_endian(uint8_t* buf, size_t len) {
+    for(size_t low = 0, high = (len - 1); high > low; --high, ++low) {
+        std::swap(buf[low], buf[high]);
+    }
+}
+
+} // nordic
+} // vendor
+} // pal
+} // ble
+

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xCrypto.h

@@ -0,0 +1,71 @@
+#ifndef NRF5X_CRYPTO_
+#define NRF5X_CRYPTO_
+
+#include <algorithm>
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+#include <stdio.h>
+#include <string.h>
+
+
+#include "mbedtls/platform.h"
+#include "mbedtls/ecdh.h"
+#include "mbedtls/memory_buffer_alloc.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ecp.h"
+
+#include "platform/NonCopyable.h"
+#include "platform/CriticalSectionLock.h"
+#include "ble/BLETypes.h"
+#include "cmsis.h"
+
+namespace ble {
+namespace pal {
+namespace vendor {
+namespace nordic {
+
+class LescCrypto : mbed::NonCopyable<LescCrypto> {
+
+public:
+    LescCrypto();
+
+    ~LescCrypto();
+
+    bool generate_keys(
+        ble::public_key_coord_t& X,
+        ble::public_key_coord_t& Y,
+        ble::public_key_coord_t& secret
+    );
+
+    bool generate_shared_secret(
+        const ble::public_key_coord_t& peer_X,
+        const ble::public_key_coord_t& peer_Y,
+        const ble::public_key_coord_t& own_secret,
+        ble::public_key_coord_t& shared_secret
+    );
+
+private:
+
+    void load_mpi(mbedtls_mpi& dest, const ble::public_key_coord_t& src);
+
+    void store_mpi(ble::public_key_coord_t& dest, const mbedtls_mpi& src);
+
+    void swap_endian(ble::public_key_coord_t& to_swap);
+
+    void swap_endian(uint8_t* buf, size_t len);
+
+    bool _initialized;
+    mbedtls_entropy_context _entropy_context;
+    mbedtls_ecp_group _group;
+};
+
+} // nordic
+} // vendor
+} // pal
+} // ble
+
+#endif // NRF5X_CRYPTO_