Migrate MAC finish calls into the software driver
Step 3/x in moving the driver. Separate commits should make for easier
review.
Additional changes on top of code movement:
* Copied the implementation of safer_memcmp from psa_crypto into
psa_cipher_mac since the mac_verify driver implementation
depends on it, and it isn't available through external linkage
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index ac772bc..4f9cf8f 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2425,59 +2425,16 @@
return( status );
}
-static psa_status_t psa_mac_finish_internal( mbedtls_psa_mac_operation_t *operation,
- uint8_t *mac,
- size_t mac_size )
-{
- if( ! operation->key_set )
- return( PSA_ERROR_BAD_STATE );
- if( operation->iv_required && ! operation->iv_set )
- return( PSA_ERROR_BAD_STATE );
-
- if( mac_size < operation->mac_size )
- return( PSA_ERROR_BUFFER_TOO_SMALL );
-
-#if defined(MBEDTLS_PSA_BUILTIN_ALG_CMAC)
- if( 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, operation->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, operation->mac_size ) );
- }
- else
-#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
- {
- /* This shouldn't happen if `operation` was initialized by
- * a setup function. */
- return( PSA_ERROR_BAD_STATE );
- }
-}
-
-psa_status_t psa_mac_sign_finish( psa_mac_operation_t *psa_operation,
+psa_status_t psa_mac_sign_finish( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
- /* Temporary recast to avoid changing a lot of lines */
- mbedtls_psa_mac_operation_t* operation = &psa_operation->ctx.mbedtls_ctx;
+ psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+ psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
- psa_status_t status;
-
- if( operation->alg == 0 )
- {
+ if( operation->id == 0 )
return( PSA_ERROR_BAD_STATE );
- }
/* Fill the output buffer with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
@@ -2488,68 +2445,32 @@
if( mac_size != 0 )
memset( mac, '!', mac_size );
- if( ! operation->is_sign )
- {
- return( PSA_ERROR_BAD_STATE );
- }
+ status = psa_driver_wrapper_mac_sign_finish( operation,
+ mac, mac_size, mac_length );
- status = psa_mac_finish_internal( operation, mac, mac_size );
+ abort_status = psa_mac_abort( operation );
- if( status == PSA_SUCCESS )
- {
- status = psa_mac_abort( psa_operation );
- if( status == PSA_SUCCESS )
- *mac_length = operation->mac_size;
- else
- memset( mac, '!', mac_size );
- }
- else
- psa_mac_abort( psa_operation );
- return( status );
+ if( status != PSA_SUCCESS && mac_size > 0 )
+ memset( mac, '!', mac_size );
+
+ return( status == PSA_SUCCESS ? abort_status : status );
}
-psa_status_t psa_mac_verify_finish( psa_mac_operation_t *psa_operation,
+psa_status_t psa_mac_verify_finish( psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length )
{
- /* Temporary recast to avoid changing a lot of lines */
- mbedtls_psa_mac_operation_t* operation = &psa_operation->ctx.mbedtls_ctx;
+ psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+ psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
- uint8_t actual_mac[PSA_MAC_MAX_SIZE];
- psa_status_t status;
-
- if( operation->alg == 0 )
- {
+ if( operation->id == 0 )
return( PSA_ERROR_BAD_STATE );
- }
- if( operation->is_sign )
- {
- return( PSA_ERROR_BAD_STATE );
- }
- if( operation->mac_size != mac_length )
- {
- status = PSA_ERROR_INVALID_SIGNATURE;
- goto cleanup;
- }
+ status = psa_driver_wrapper_mac_verify_finish( operation,
+ mac, mac_length );
+ abort_status = psa_mac_abort( operation );
- status = psa_mac_finish_internal( operation,
- actual_mac, sizeof( actual_mac ) );
- if( status != PSA_SUCCESS )
- goto cleanup;
-
- if( safer_memcmp( mac, actual_mac, mac_length ) != 0 )
- status = PSA_ERROR_INVALID_SIGNATURE;
-
-cleanup:
- if( status == PSA_SUCCESS )
- status = psa_mac_abort( psa_operation );
- else
- psa_mac_abort( psa_operation );
-
- mbedtls_platform_zeroize( actual_mac, sizeof( actual_mac ) );
-
- return( status );
+ return( status == PSA_SUCCESS ? abort_status : status );
}