mbedtls/library/psa_crypto.c
Gilles Peskine e59236fc17 Add PSA crypto module
New module psa_crypto.c (MBEDTLS_PSA_CRYPTO_C):
Platform Security Architecture compatibility layer on top of
libmedcrypto.

Implement psa_crypto_init function which sets up a RNG.

Add a mbedtls_psa_crypto_free function which deinitializes the
library.

Define a first batch of error codes.
2018-09-05 10:59:00 +03:00

98 lines
2.7 KiB
C

/*
* PSA crypto layer on top of Mbed TLS crypto
*/
/* Copyright (C) 2018, ARM Limited, 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 is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_PSA_CRYPTO_C)
#include "psa/crypto.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/entropy.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;
}
typedef struct {
int initialized;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
} psa_global_data_t;
static psa_global_data_t global_data;
static psa_status_t mbedtls_to_psa_error( int ret )
{
switch( ret )
{
case 0:
return( PSA_SUCCESS );
case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
default:
return( PSA_ERROR_UNKNOWN_ERROR );
}
}
void mbedtls_psa_crypto_free( void )
{
mbedtls_ctr_drbg_free( &global_data.ctr_drbg );
mbedtls_entropy_free( &global_data.entropy );
mbedtls_zeroize( &global_data, sizeof( global_data ) );
}
psa_status_t psa_crypto_init( void )
{
int ret;
const unsigned char drbg_seed[] = "PSA";
if( global_data.initialized != 0 )
return( PSA_SUCCESS );
mbedtls_zeroize( &global_data, sizeof( global_data ) );
mbedtls_entropy_init( &global_data.entropy );
mbedtls_ctr_drbg_init( &global_data.ctr_drbg );
ret = mbedtls_ctr_drbg_seed( &global_data.ctr_drbg,
mbedtls_entropy_func,
&global_data.entropy,
drbg_seed, sizeof( drbg_seed ) - 1 );
if( ret != 0 )
goto exit;
exit:
if( ret != 0 )
mbedtls_psa_crypto_free( );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_PSA_CRYPTO_C */