mbedtls/library/psa_crypto_mac.c
Ronald Cron 0266cfed51 psa: Remove test code in the library
The current testing of the PSA configuration is
based on test code located in the library itself.

Remove this code as we are moving to using a
test library instead.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2021-12-06 07:50:27 +01:00

502 lines
16 KiB
C

/*
* PSA MAC layer on top of Mbed TLS software crypto
*/
/*
* Copyright The Mbed TLS Contributors
* 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 "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#include <psa/crypto.h>
#include "psa_crypto_core.h"
#include "psa_crypto_mac.h"
#include <mbedtls/md.h>
#include <mbedtls/error.h>
#include <string.h>
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
static psa_status_t psa_hmac_abort_internal(
mbedtls_psa_hmac_operation_t *hmac )
{
mbedtls_platform_zeroize( hmac->opad, sizeof( hmac->opad ) );
return( psa_hash_abort( &hmac->hash_ctx ) );
}
static psa_status_t psa_hmac_setup_internal(
mbedtls_psa_hmac_operation_t *hmac,
const uint8_t *key,
size_t key_length,
psa_algorithm_t hash_alg )
{
uint8_t ipad[PSA_HMAC_MAX_HASH_BLOCK_SIZE];
size_t i;
size_t hash_size = PSA_HASH_LENGTH( hash_alg );
size_t block_size = PSA_HASH_BLOCK_LENGTH( hash_alg );
psa_status_t status;
hmac->alg = hash_alg;
/* Sanity checks on block_size, to guarantee that there won't be a buffer
* overflow below. This should never trigger if the hash algorithm
* is implemented correctly. */
/* The size checks against the ipad and opad buffers cannot be written
* `block_size > sizeof( ipad ) || block_size > sizeof( hmac->opad )`
* because that triggers -Wlogical-op on GCC 7.3. */
if( block_size > sizeof( ipad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size > sizeof( hmac->opad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size < hash_size )
return( PSA_ERROR_NOT_SUPPORTED );
if( key_length > block_size )
{
status = psa_hash_compute( hash_alg, key, key_length,
ipad, sizeof( ipad ), &key_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
/* A 0-length key is not commonly used in HMAC when used as a MAC,
* but it is permitted. It is common when HMAC is used in HKDF, for
* example. Don't call `memcpy` in the 0-length because `key` could be
* an invalid pointer which would make the behavior undefined. */
else if( key_length != 0 )
memcpy( ipad, key, key_length );
/* ipad contains the key followed by garbage. Xor and fill with 0x36
* to create the ipad value. */
for( i = 0; i < key_length; i++ )
ipad[i] ^= 0x36;
memset( ipad + key_length, 0x36, block_size - key_length );
/* Copy the key material from ipad to opad, flipping the requisite bits,
* and filling the rest of opad with the requisite constant. */
for( i = 0; i < key_length; i++ )
hmac->opad[i] = ipad[i] ^ 0x36 ^ 0x5C;
memset( hmac->opad + key_length, 0x5C, block_size - key_length );
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &hmac->hash_ctx, ipad, block_size );
cleanup:
mbedtls_platform_zeroize( ipad, sizeof( ipad ) );
return( status );
}
static psa_status_t psa_hmac_update_internal(
mbedtls_psa_hmac_operation_t *hmac,
const uint8_t *data,
size_t data_length )
{
return( psa_hash_update( &hmac->hash_ctx, data, data_length ) );
}
static psa_status_t psa_hmac_finish_internal(
mbedtls_psa_hmac_operation_t *hmac,
uint8_t *mac,
size_t mac_size )
{
uint8_t tmp[PSA_HASH_MAX_SIZE];
psa_algorithm_t hash_alg = hmac->alg;
size_t hash_size = 0;
size_t block_size = PSA_HASH_BLOCK_LENGTH( hash_alg );
psa_status_t status;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
return( status );
/* From here on, tmp needs to be wiped. */
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, hmac->opad, block_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, tmp, hash_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
goto exit;
memcpy( mac, tmp, mac_size );
exit:
mbedtls_platform_zeroize( tmp, hash_size );
return( status );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
static psa_status_t cmac_setup( mbedtls_psa_mac_operation_t *operation,
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
#if defined(PSA_WANT_KEY_TYPE_DES)
/* Mbed TLS CMAC does not accept 3DES with only two keys, nor does it accept
* to do CMAC with pure DES, so return NOT_SUPPORTED here. */
if( psa_get_key_type( attributes ) == PSA_KEY_TYPE_DES &&
( psa_get_key_bits( attributes ) == 64 ||
psa_get_key_bits( attributes ) == 128 ) )
return( PSA_ERROR_NOT_SUPPORTED );
#endif
const mbedtls_cipher_info_t * cipher_info =
mbedtls_cipher_info_from_psa(
PSA_ALG_CMAC,
psa_get_key_type( attributes ),
psa_get_key_bits( attributes ),
NULL );
if( cipher_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
ret = mbedtls_cipher_setup( &operation->ctx.cmac, cipher_info );
if( ret != 0 )
goto exit;
ret = mbedtls_cipher_cmac_starts( &operation->ctx.cmac,
key_buffer,
psa_get_key_bits( attributes ) );
exit:
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
/* Implement the PSA driver MAC interface on top of mbed TLS if either the
* software driver or the test driver requires it. */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
/* Initialize this driver's MAC operation structure. Once this function has been
* called, mbedtls_psa_mac_abort can run and will do the right thing. */
static psa_status_t mac_init(
mbedtls_psa_mac_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
operation->alg = alg;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
if( PSA_ALG_FULL_LENGTH_MAC( operation->alg ) == PSA_ALG_CMAC )
{
mbedtls_cipher_init( &operation->ctx.cmac );
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
/* We'll set up the hash operation later in psa_hmac_setup_internal. */
operation->ctx.hmac.alg = 0;
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
(void) operation;
status = PSA_ERROR_NOT_SUPPORTED;
}
if( status != PSA_SUCCESS )
memset( operation, 0, sizeof( *operation ) );
return( status );
}
psa_status_t mbedtls_psa_mac_abort( mbedtls_psa_mac_operation_t *operation )
{
if( operation->alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
else
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
if( PSA_ALG_FULL_LENGTH_MAC( operation->alg ) == PSA_ALG_CMAC )
{
mbedtls_cipher_free( &operation->ctx.cmac );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
psa_hmac_abort_internal( &operation->ctx.hmac );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
goto bad_state;
}
operation->alg = 0;
return( PSA_SUCCESS );
bad_state:
/* If abort is called on an uninitialized object, we can't trust
* anything. Wipe the object in case it contains confidential data.
* This may result in a memory leak if a pointer gets overwritten,
* but it's too late to do anything about this. */
memset( operation, 0, sizeof( *operation ) );
return( PSA_ERROR_BAD_STATE );
}
static psa_status_t psa_mac_setup( mbedtls_psa_mac_operation_t *operation,
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
/* A context must be freshly initialized before it can be set up. */
if( operation->alg != 0 )
return( PSA_ERROR_BAD_STATE );
status = mac_init( operation, alg );
if( status != PSA_SUCCESS )
return( status );
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
if( PSA_ALG_FULL_LENGTH_MAC( alg ) == PSA_ALG_CMAC )
{
/* Key buffer size for CMAC is dictated by the key bits set on the
* attributes, and previously validated by the core on key import. */
(void) key_buffer_size;
status = cmac_setup( operation, attributes, key_buffer );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if( PSA_ALG_IS_HMAC( alg ) )
{
status = psa_hmac_setup_internal( &operation->ctx.hmac,
key_buffer,
key_buffer_size,
PSA_ALG_HMAC_GET_HASH( alg ) );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
(void) attributes;
(void) key_buffer;
(void) key_buffer_size;
status = PSA_ERROR_NOT_SUPPORTED;
}
if( status != PSA_SUCCESS )
mbedtls_psa_mac_abort( operation );
return( status );
}
psa_status_t mbedtls_psa_mac_sign_setup(
mbedtls_psa_mac_operation_t *operation,
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, attributes,
key_buffer, key_buffer_size, alg ) );
}
psa_status_t mbedtls_psa_mac_verify_setup(
mbedtls_psa_mac_operation_t *operation,
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, attributes,
key_buffer, key_buffer_size, alg ) );
}
psa_status_t mbedtls_psa_mac_update(
mbedtls_psa_mac_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
if( operation->alg == 0 )
return( PSA_ERROR_BAD_STATE );
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
if( PSA_ALG_FULL_LENGTH_MAC( operation->alg ) == PSA_ALG_CMAC )
{
return( mbedtls_to_psa_error(
mbedtls_cipher_cmac_update( &operation->ctx.cmac,
input, input_length ) ) );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
return( psa_hmac_update_internal( &operation->ctx.hmac,
input, input_length ) );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
(void) input;
(void) input_length;
return( PSA_ERROR_BAD_STATE );
}
}
static psa_status_t psa_mac_finish_internal(
mbedtls_psa_mac_operation_t *operation,
uint8_t *mac, size_t mac_size )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
if( PSA_ALG_FULL_LENGTH_MAC( operation->alg ) == PSA_ALG_CMAC )
{
uint8_t tmp[PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE];
int ret = mbedtls_cipher_cmac_finish( &operation->ctx.cmac, tmp );
if( ret == 0 )
memcpy( mac, tmp, mac_size );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
return( psa_hmac_finish_internal( &operation->ctx.hmac,
mac, mac_size ) );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
(void) operation;
(void) mac;
(void) mac_size;
return( PSA_ERROR_BAD_STATE );
}
}
psa_status_t mbedtls_psa_mac_sign_finish(
mbedtls_psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->alg == 0 )
return( PSA_ERROR_BAD_STATE );
status = psa_mac_finish_internal( operation, mac, mac_size );
if( status == PSA_SUCCESS )
*mac_length = mac_size;
return( status );
}
psa_status_t mbedtls_psa_mac_verify_finish(
mbedtls_psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length )
{
uint8_t actual_mac[PSA_MAC_MAX_SIZE];
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->alg == 0 )
return( PSA_ERROR_BAD_STATE );
/* Consistency check: requested MAC length fits our local buffer */
if( mac_length > sizeof( actual_mac ) )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_mac_finish_internal( operation, actual_mac, mac_length );
if( status != PSA_SUCCESS )
goto cleanup;
if( mbedtls_psa_safer_memcmp( mac, actual_mac, mac_length ) != 0 )
status = PSA_ERROR_INVALID_SIGNATURE;
cleanup:
mbedtls_platform_zeroize( actual_mac, sizeof( actual_mac ) );
return( status );
}
psa_status_t mbedtls_psa_mac_compute(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
mbedtls_psa_mac_operation_t operation = MBEDTLS_PSA_MAC_OPERATION_INIT;
status = psa_mac_setup( &operation,
attributes, key_buffer, key_buffer_size,
alg );
if( status != PSA_SUCCESS )
goto exit;
if( input_length > 0 )
{
status = mbedtls_psa_mac_update( &operation, input, input_length );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_mac_finish_internal( &operation, mac, mac_size );
if( status == PSA_SUCCESS )
*mac_length = mac_size;
exit:
mbedtls_psa_mac_abort( &operation );
return( status );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC || MBEDTLS_PSA_BUILTIN_ALG_CMAC */
#endif /* MBEDTLS_PSA_CRYPTO_C */