2021-03-03 14:55:52 +01:00

533 lines
16 KiB
C

/*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Copyright (C) 2019-2020 STMicroelectronics, All Rights Reserved
* 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.
*
* This file implements ST GCM HW services based on API from mbed TLS
*/
/* Includes ------------------------------------------------------------------*/
#include "mbedtls/gcm.h"
#if defined(MBEDTLS_GCM_C)
#if defined(MBEDTLS_GCM_ALT)
#include <string.h>
#include "mbedtls/platform_util.h"
#include "mbedtls/platform.h"
/* 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 )
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define IV_LENGTH 12U /* implementations restrict support to 96 bits */
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
#define AAD_WORD_ALIGN 4U /* implementations restrict AAD support on a */
/* buffer multiple of 32 bits */
#endif
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/*
* Initialize a context
*/
void mbedtls_gcm_init( mbedtls_gcm_context *ctx )
{
GCM_VALIDATE( ctx != NULL );
__disable_irq();
#if defined(MBEDTLS_THREADING_C)
/* mutex cannot be initialized twice */
if ( !cryp_mutex_started )
{
mbedtls_mutex_init( &cryp_mutex );
cryp_mutex_started = 1;
}
#endif /* MBEDTLS_THREADING_C */
cryp_context_count++;
__enable_irq();
cryp_zeroize( (void*)ctx, sizeof(mbedtls_gcm_context) );
}
int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
mbedtls_cipher_id_t cipher,
const unsigned char *key,
unsigned int keybits )
{
unsigned int i;
int ret = 0;
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( key != NULL );
/* Protect context access */
/* (it may occur at a same time in a threaded environment) */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &cryp_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C */
switch (keybits)
{
case 128:
ctx->hcryp_gcm.Init.KeySize = CRYP_KEYSIZE_128B;
break;
case 192:
#if ( USE_AES_KEY192 == 1 )
ctx->hcryp_gcm.Init.KeySize = CRYP_KEYSIZE_192B;
break;
#else
ret = MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED;
goto exit;
#endif /* USE_AES_KEY192 */
case 256:
ctx->hcryp_gcm.Init.KeySize = CRYP_KEYSIZE_256B;
break;
default :
ret = MBEDTLS_ERR_GCM_BAD_INPUT;
goto exit;
}
/* Format and fill AES key */
for( i=0; i < (keybits/32); i++ )
GET_UINT32_BE( ctx->gcm_key[i], key, 4*i );
/* include the appropriate instance name */
#if defined (AES)
ctx->hcryp_gcm.Instance = AES;
ctx->hcryp_gcm.Init.Algorithm = CRYP_AES_GCM_GMAC;
#elif defined (AES1)
ctx->hcryp_gcm.Instance = AES1;
ctx->hcryp_gcm.Init.Algorithm = CRYP_AES_GCM_GMAC;
#else /* CRYP */
ctx->hcryp_gcm.Instance = CRYP;
ctx->hcryp_gcm.Init.Algorithm = CRYP_AES_GCM;
#endif /* AES */
ctx->hcryp_gcm.Init.DataType = CRYP_DATATYPE_8B;
ctx->hcryp_gcm.Init.DataWidthUnit = CRYP_DATAWIDTHUNIT_BYTE;
ctx->hcryp_gcm.Init.pKey = ctx->gcm_key;
if ( HAL_CRYP_Init( &ctx->hcryp_gcm ) != HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
/* allow multi-context of CRYP : save context */
ctx->ctx_save_cr = ctx->hcryp_gcm.Instance->CR;
exit :
/* Free context access */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cryp_mutex ) != 0 )
ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
#endif /* MBEDTLS_THREADING_C */
return( ret );
}
int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
int mode,
const unsigned char *iv,
size_t iv_len,
const unsigned char *add,
size_t add_len )
{
int ret = 0;
unsigned int i;
__ALIGN_BEGIN static uint32_t iv_32B[4] __ALIGN_END;
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( mode != MBEDTLS_GCM_ENCRYPT || mode != MBEDTLS_GCM_DECRYPT );
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 ||
( (uint64_t) iv_len ) >> 61 != 0 ||
( (uint64_t) add_len ) >> 61 != 0 )
{
return( MBEDTLS_ERR_GCM_BAD_INPUT );
}
/* implementation restrict support to the length of 96 bits */
if( IV_LENGTH != iv_len )
{
return( MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED );
}
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* implementation restrict support to a buffer multiple of 32 bits */
if ((add_len % AAD_WORD_ALIGN) != 0U)
{
return( MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED );
}
#endif
/* Protect context access */
/* (it may occur at a same time in a threaded environment) */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &cryp_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C */
if ( HAL_CRYP_Init( &ctx->hcryp_gcm ) != HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
/* allow multi-context of CRYP use: restore context */
ctx->hcryp_gcm.Instance->CR = ctx->ctx_save_cr;
ctx->mode = mode;
ctx->len = 0;
/* Set IV with invert endianness */
for( i=0; i < 3; i++ )
GET_UINT32_BE( iv_32B[i], iv, 4*i );
/* According to NIST specification, the counter value is 0x2 when
processing the first block of payload */
iv_32B[3] = 0x00000002;
ctx->hcryp_gcm.Init.pInitVect = iv_32B;
if ( add_len > 0 )
{
ctx->hcryp_gcm.Init.Header = (uint32_t *)add;
#if defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* header buffer in byte length */
ctx->hcryp_gcm.Init.HeaderSize = (uint32_t)add_len;
#else
/* header buffer in word length */
ctx->hcryp_gcm.Init.HeaderSize = (uint32_t)(add_len/AAD_WORD_ALIGN);
#endif
}
else
{
ctx->hcryp_gcm.Init.Header = NULL;
ctx->hcryp_gcm.Init.HeaderSize = 0;
}
#if defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* Additional Authentication Data in bytes unit */
ctx->hcryp_gcm.Init.HeaderWidthUnit = CRYP_HEADERWIDTHUNIT_BYTE;
#endif
/* Do not Allow IV reconfiguration at every gcm update */
ctx->hcryp_gcm.Init.KeyIVConfigSkip = CRYP_KEYIVCONFIG_ONCE;
/* reconfigure the CRYP */
if ( HAL_CRYP_SetConfig( &ctx->hcryp_gcm, &ctx->hcryp_gcm.Init ) != HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
/* allow multi-context of CRYP : save context */
ctx->ctx_save_cr = ctx->hcryp_gcm.Instance->CR;
exit:
/* Free context access */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cryp_mutex ) != 0 )
ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
#endif /* MBEDTLS_THREADING_C */
return( ret );
}
int mbedtls_gcm_update( mbedtls_gcm_context *ctx,
size_t length,
const unsigned char *input,
unsigned char *output )
{
int ret = 0;
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
size_t rest_length = 0;
#endif
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 );
/* Total length is restricted to 2^39 - 256 bits, ie 2^36 - 2^5 bytes
* Also check for possible overflow */
if( ( (ctx->len + length) < ctx->len ) ||
( (uint64_t)(ctx->len + length) > 0xFFFFFFFE0ull ) )
{
return( MBEDTLS_ERR_GCM_BAD_INPUT );
}
/* Protect context access */
/* (it may occur at a same time in a threaded environment) */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &cryp_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C */
/* allow multi-context of CRYP use: restore context */
ctx->hcryp_gcm.Instance->CR = ctx->ctx_save_cr;
ctx->len += length;
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* compute remaining data (data buffer in word) */
if ((length % AAD_WORD_ALIGN) != 0U)
rest_length = length % AAD_WORD_ALIGN;
#endif
if( ctx->mode == MBEDTLS_GCM_DECRYPT )
{
if ( HAL_CRYP_Decrypt( &ctx->hcryp_gcm,
(uint32_t *)input,
length,
(uint32_t *)output,
ST_CRYP_TIMEOUT ) != HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* manage last bytes */
if (rest_length !=0 )
{
if (HAL_CRYP_Decrypt(&ctx->hcryp_gcm,
(uint32_t *)(input + (length/AAD_WORD_ALIGN)),
rest_length,
(uint32_t *)(output + (length/AAD_WORD_ALIGN)),
ST_CRYP_TIMEOUT) != HAL_OK)
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
}
#endif
}
else
{
if ( HAL_CRYP_Encrypt( &ctx->hcryp_gcm,
(uint32_t *)input,
length,
(uint32_t *)output,
ST_CRYP_TIMEOUT ) != HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
#if !defined(STM32_AAD_ANY_LENGTH_SUPPORT)
/* manage last bytes */
if (rest_length !=0 )
{
if (HAL_CRYP_Encrypt(&ctx->hcryp_gcm,
(uint32_t *)(input + (length/AAD_WORD_ALIGN)),
rest_length,
(uint32_t *)(output + (length/AAD_WORD_ALIGN)),
ST_CRYP_TIMEOUT) != HAL_OK)
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
}
#endif
}
/* allow multi-context of CRYP : save context */
ctx->ctx_save_cr = ctx->hcryp_gcm.Instance->CR;
exit:
/* Free context access */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cryp_mutex ) != 0 )
ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
#endif /* MBEDTLS_THREADING_C */
return( ret );
}
int mbedtls_gcm_finish( mbedtls_gcm_context *ctx,
unsigned char *tag,
size_t tag_len )
{
int ret = 0;
__ALIGN_BEGIN uint8_t mac[16] __ALIGN_END; /* temporary mac */
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( tag != NULL );
if( tag_len > 16 || tag_len < 4 )
return( MBEDTLS_ERR_GCM_BAD_INPUT );
/* Protect context access */
/* (it may occur at a same time in a threaded environment) */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &cryp_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C */
/* allow multi-context of CRYP use: restore context */
ctx->hcryp_gcm.Instance->CR = ctx->ctx_save_cr;
/* Tag has a variable length */
memset(mac, 0, sizeof(mac));
/* Generate the authentication TAG */
if ( HAL_CRYPEx_AESGCM_GenerateAuthTAG( &ctx->hcryp_gcm,
(uint32_t *)mac,
ST_CRYP_TIMEOUT )!= HAL_OK )
{
ret = MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
goto exit;
}
memcpy( tag, mac, tag_len );
/* allow multi-context of CRYP : save context */
ctx->ctx_save_cr = ctx->hcryp_gcm.Instance->CR;
exit:
/* Free context access */
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cryp_mutex ) != 0 )
ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
#endif /* MBEDTLS_THREADING_C */
return( ret );
}
int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
int mode,
size_t length,
const unsigned char *iv,
size_t iv_len,
const unsigned char *add,
size_t add_len,
const unsigned char *input,
unsigned char *output,
size_t tag_len,
unsigned char *tag )
{
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 );
if( ( ret = mbedtls_gcm_update( ctx, length, input, output ) ) != 0 )
return( ret );
if( ( ret = mbedtls_gcm_finish( ctx, tag, tag_len ) ) != 0 )
return( ret );
return( 0 );
}
int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
size_t length,
const unsigned char *iv,
size_t iv_len,
const unsigned char *add,
size_t add_len,
const unsigned char *tag,
size_t tag_len,
const unsigned char *input,
unsigned char *output )
{
int ret;
unsigned char check_tag[16];
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 )
{
return( ret );
}
/* Check tag in "constant-time" */
for( diff = 0, i = 0; i < tag_len; i++ )
diff |= tag[i] ^ check_tag[i];
if( diff != 0 )
{
mbedtls_platform_zeroize( output, length );
return( MBEDTLS_ERR_GCM_AUTH_FAILED );
}
return( 0 );
}
void mbedtls_gcm_free( mbedtls_gcm_context *ctx )
{
if( ctx == NULL )
return;
__disable_irq();
if ( cryp_context_count > 0 )
cryp_context_count--;
#if defined(MBEDTLS_THREADING_C)
if ( cryp_mutex_started )
{
mbedtls_mutex_free( &cryp_mutex );
cryp_mutex_started = 0;
}
#endif /* MBEDTLS_THREADING_C */
__enable_irq();
/* Shut down CRYP on last context */
if ( cryp_context_count == 0 )
HAL_CRYP_DeInit( &ctx->hcryp_gcm );
cryp_zeroize( (void*)ctx, sizeof(mbedtls_gcm_context) );
}
#endif /*MBEDTLS_GCM_ALT*/
#endif /*MBEDTLS_GCM_C*/