Handle 64bytes per 64 bytes

+ remove unused includes files

features/mbedtls/targets/TARGET_STM/md5_alt.c

@@ -0,0 +1,127 @@
+/*
+ *  MD5 hw acceleration
+ *******************************************************************************
+ * Copyright (c) 2017, STMicroelectronics
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+#include "mbedtls/md5.h"
+
+#if defined(MBEDTLS_MD5_ALT)
+#include "mbedtls/platform.h"
+
+/* Implementation that should never be optimized out by the compiler */
+static void mbedtls_zeroize( void *v, size_t n ) {
+    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+void mbedtls_md5_init( mbedtls_md5_context *ctx )
+{
+    mbedtls_zeroize( ctx, sizeof( mbedtls_md5_context ) );
+
+    /* Enable HASH clock */
+    __HAL_RCC_HASH_CLK_ENABLE();
+
+}
+
+void mbedtls_md5_free( mbedtls_md5_context *ctx )
+{
+    if( ctx == NULL )
+        return;
+
+    /* Force the HASH Periheral Clock Reset */
+    __HAL_RCC_HASH_FORCE_RESET();
+
+    /* Release the HASH Periheral Clock Reset */
+    __HAL_RCC_HASH_RELEASE_RESET();
+
+    mbedtls_zeroize( ctx, sizeof( mbedtls_md5_context ) );
+}
+
+void mbedtls_md5_clone( mbedtls_md5_context *dst,
+                        const mbedtls_md5_context *src )
+{
+    *dst = *src;
+}
+
+/*
+ * MD5 context setup
+ */
+void mbedtls_md5_starts( mbedtls_md5_context *ctx )
+{
+    /* HASH IP initialization */
+    HAL_HASH_DeInit(&ctx->hhash_md5);
+
+    /* HASH Configuration */
+    ctx->hhash_md5.Init.DataType = HASH_DATATYPE_8B;
+    if (HAL_HASH_Init(&ctx->hhash_md5) == HAL_ERROR) {
+        // return error code
+        return;
+    }
+}
+
+void mbedtls_md5_process( mbedtls_md5_context *ctx, const unsigned char data[64] )
+{
+    HAL_HASH_MD5_Accumulate(&ctx->hhash_md5, (uint8_t *)data, 64);
+}
+
+/*
+ * MD5 process buffer
+ */
+void mbedtls_md5_update( mbedtls_md5_context *ctx, const unsigned char *input, size_t ilen )
+{
+    unsigned char i=0;
+    int currentlen = ilen;
+    /* store mechanism to handle 64 bytes per 64 bytes */
+    while ((currentlen+ctx->sbuf_len) >=64) {
+        if (ctx->sbuf_len ==0) { /* straight forward */
+            mbedtls_md5_process(ctx, input+(i*64));
+        } else {
+            memcpy(ctx->sbuf+ctx->sbuf_len, input+(i*64),64-ctx->sbuf_len);
+            mbedtls_md5_process(ctx, ctx->sbuf);
+            memcpy(ctx->sbuf,input+(i+1)*64-ctx->sbuf_len, ctx->sbuf_len);
+            // ctx->sbuf_len remains the same
+        }
+        currentlen -= 64;
+        i++;
+    }
+    if (currentlen <0) {
+        currentlen +=64;
+    }
+    /* Store the remaining <64 values */
+    memcpy(ctx->sbuf+ctx->sbuf_len, input+(i*64), currentlen);
+    ctx->sbuf_len += currentlen;
+
+}
+
+/*
+ * MD5 final digest
+ */
+void mbedtls_md5_finish( mbedtls_md5_context *ctx, unsigned char output[16] )
+{
+    if (ctx->sbuf_len > 0) {
+        HAL_HASH_MD5_Accumulate(&ctx->hhash_md5, ctx->sbuf, ctx->sbuf_len);
+    }
+    mbedtls_zeroize( ctx->sbuf, 64);
+    ctx->sbuf_len = 0;
+    __HAL_HASH_START_DIGEST();
+
+    if (HAL_HASH_MD5_Finish(&ctx->hhash_md5, output, 10)) {
+        // error code to be returned
+    }
+}
+
+#endif /* MBEDTLS_MD5_ALT */

features/mbedtls/targets/TARGET_STM/md5_alt.h

@@ -23,8 +23,6 @@
 #define MBEDTLS_MD5_ALT_H
 
 #if defined(MBEDTLS_MD5_ALT)
-#include "mbedtls/platform.h"
-#include "mbedtls/config.h"
 
 #include "cmsis.h"
 #include <string.h>
@@ -35,10 +33,15 @@ extern "C" {
 
 /**
  * \brief          MD5 context structure
+ * \note     HAL_HASH_MD5_Accumulate cannot handle less than 4 bytes, unless it is the last call to the  function
+ *           A 64 bytes buffer is used to save values and handle the processing 64 bytes per 64 bytes
+ *           If MD5_finish is called and sbuf_len>0, the remaining bytes are accumulated prior to the call to HAL_HASH_MD5_Finish
  */
 typedef struct
 {
-    HASH_HandleTypeDef hhash_md5;
+  HASH_HandleTypeDef hhash_md5;/*!< ST HAL HASH struct */
+  unsigned char sbuf[64]; /*!< 64 buffer to store values so that algorithm is caled once the buffer is filled */
+  unsigned char sbuf_len; /*!< number of bytes to be processed in sbuf */
 }
 mbedtls_md5_context;