From e63912ff44d18cd02ce20f8a04fd0bd04ae23325 Mon Sep 17 00:00:00 2001 From: adustm Date: Thu, 8 Jun 2017 17:00:08 +0200 Subject: [PATCH] Check that the HASH is not busy before save and restore iHW registers --- .../mbedtls/targets/TARGET_STM/sha1_alt.c | 52 +++++++++++++++---- .../mbedtls/targets/TARGET_STM/sha1_alt.h | 3 +- 2 files changed, 44 insertions(+), 11 deletions(-) diff --git a/features/mbedtls/targets/TARGET_STM/sha1_alt.c b/features/mbedtls/targets/TARGET_STM/sha1_alt.c index 58b749c7d7..98317c21fa 100644 --- a/features/mbedtls/targets/TARGET_STM/sha1_alt.c +++ b/features/mbedtls/targets/TARGET_STM/sha1_alt.c @@ -26,26 +26,44 @@ static void mbedtls_zeroize( void *v, size_t n ) { volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; } -static void st_sha1_restore_hw_context(mbedtls_sha1_context *ctx) +static int st_sha1_restore_hw_context(mbedtls_sha1_context *ctx) { uint32_t i; + uint32_t tickstart; /* allow multi-instance of HASH use: save context for HASH HW module CR */ + /* Check that there is no HASH activity on going */ + tickstart = HAL_GetTick(); + while ((HASH->SR & (HASH_FLAG_BUSY | HASH_FLAG_DMAS)) != 0) { + if ((HAL_GetTick() - tickstart) > ST_SHA1_TIMEOUT) { + return 0; // timeout: HASH processor is busy + } + } HASH->STR = ctx->ctx_save_str; - HASH->CR = (ctx->ctx_save_cr|HASH_CR_INIT); + HASH->CR = (ctx->ctx_save_cr | HASH_CR_INIT); for (i=0;i<38;i++) { HASH->CSR[i] = ctx->ctx_save_csr[i]; } + return 1; } -static void st_sha1_save_hw_context(mbedtls_sha1_context *ctx) +static int st_sha1_save_hw_context(mbedtls_sha1_context *ctx) { uint32_t i; + uint32_t tickstart; + /* Check that there is no HASH activity on going */ + tickstart = HAL_GetTick(); + while ((HASH->SR & (HASH_FLAG_BUSY | HASH_FLAG_DMAS)) != 0) { + if ((HAL_GetTick() - tickstart) > ST_SHA1_TIMEOUT) { + return 0; // timeout: HASH processor is busy + } + } /* allow multi-instance of HASH use: restore context for HASH HW module CR */ ctx->ctx_save_cr = HASH->CR; ctx->ctx_save_str = HASH->STR; for (i=0;i<38;i++) { ctx->ctx_save_csr[i] = HASH->CSR[i]; } + return 1; } void mbedtls_sha1_init( mbedtls_sha1_context *ctx ) @@ -84,23 +102,31 @@ void mbedtls_sha1_starts( mbedtls_sha1_context *ctx ) // error found to be returned return; } - st_sha1_save_hw_context(ctx); + if (st_sha1_save_hw_context(ctx) != 1) { + return; // return HASH_BUSY timeout Error here + } } void mbedtls_sha1_process( mbedtls_sha1_context *ctx, const unsigned char data[ST_SHA1_BLOCK_SIZE] ) { - st_sha1_restore_hw_context(ctx); + if (st_sha1_restore_hw_context(ctx) != 1) { + return; // Return HASH_BUSY timout error here + } if (HAL_HASH_SHA1_Accumulate(&ctx->hhash_sha1, (uint8_t *) data, ST_SHA1_BLOCK_SIZE) != 0) { return; // Return error code } - st_sha1_save_hw_context(ctx); + if (st_sha1_save_hw_context(ctx) != 1) { + return; // return HASH_BUSY timeout Error here + } } void mbedtls_sha1_update( mbedtls_sha1_context *ctx, const unsigned char *input, size_t ilen ) { size_t currentlen = ilen; - st_sha1_restore_hw_context(ctx); + if (st_sha1_restore_hw_context(ctx) != 1) { + return; // Return HASH_BUSY timout error here + } // store mechanism to accumulate ST_SHA1_BLOCK_SIZE bytes (512 bits) in the HW if (currentlen == 0){ // only change HW status is size if 0 @@ -130,12 +156,16 @@ void mbedtls_sha1_update( mbedtls_sha1_context *ctx, const unsigned char *input, memcpy(ctx->sbuf, input + ilen - ctx->sbuf_len, ctx->sbuf_len); } } - st_sha1_save_hw_context(ctx); + if (st_sha1_save_hw_context(ctx) != 1) { + return; // return HASH_BUSY timeout Error here + } } void mbedtls_sha1_finish( mbedtls_sha1_context *ctx, unsigned char output[20] ) { - st_sha1_restore_hw_context(ctx); + if (st_sha1_restore_hw_context(ctx) != 1) { + return; // Return HASH_BUSY timout error here + } if (ctx->sbuf_len > 0) { if (HAL_HASH_SHA1_Accumulate(&ctx->hhash_sha1, ctx->sbuf, ctx->sbuf_len) != 0) { @@ -149,7 +179,9 @@ void mbedtls_sha1_finish( mbedtls_sha1_context *ctx, unsigned char output[20] ) if (HAL_HASH_SHA1_Finish(&ctx->hhash_sha1, output, 10) != 0){ return; // error code to be returned } - st_sha1_save_hw_context(ctx); + if (st_sha1_save_hw_context(ctx) != 1) { + return; // return HASH_BUSY timeout Error here + } } #endif /*MBEDTLS_SHA1_ALT*/ diff --git a/features/mbedtls/targets/TARGET_STM/sha1_alt.h b/features/mbedtls/targets/TARGET_STM/sha1_alt.h index 804eccd97f..4db4880bea 100644 --- a/features/mbedtls/targets/TARGET_STM/sha1_alt.h +++ b/features/mbedtls/targets/TARGET_STM/sha1_alt.h @@ -32,7 +32,8 @@ extern "C" { #endif -#define ST_SHA1_BLOCK_SIZE (64) // HW handles 512 bits, ie 64 bytes +#define ST_SHA1_BLOCK_SIZE ((size_t) 64) // HW handles 512 bits, ie 64 bytes +#define ST_SHA1_TIMEOUT ((uint32_t) 3) /** * \brief SHA-1 context structure * \note HAL_HASH_SHA1_Accumulate will accumulate 512 bits packets, unless it is the last call to the function