mbedtls/library/psa_crypto_se.c

87 lines
2.5 KiB
C

/*
* PSA crypto support for secure element drivers
*/
/* Copyright (C) 2019, 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_SE_C)
#include <assert.h>
#include <string.h>
#include "psa_crypto_se.h"
typedef struct
{
psa_key_lifetime_t lifetime;
const psa_drv_se_t *methods;
} method_table_entry_t;
static method_table_entry_t driver_table[PSA_MAX_SE_DRIVERS];
psa_status_t psa_register_se_driver(
psa_key_lifetime_t lifetime,
const psa_drv_se_t *methods)
{
size_t i;
if( methods->hal_version != PSA_DRV_SE_HAL_VERSION )
return( PSA_ERROR_NOT_SUPPORTED );
/* Driver table entries are 0-initialized. 0 is not a valid driver
* lifetime because it means a volatile key. */
#if defined(static_assert)
static_assert( PSA_KEY_LIFETIME_VOLATILE == 0,
"Secure element support requires 0 to mean a volatile key" );
#endif
if( lifetime == PSA_KEY_LIFETIME_VOLATILE ||
lifetime == PSA_KEY_LIFETIME_PERSISTENT )
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
for( i = 0; i < PSA_MAX_SE_DRIVERS; i++ )
{
if( driver_table[i].lifetime == 0 )
break;
/* Check that lifetime isn't already in use up to the first free
* entry. Since entries are created in order and never deleted,
* there can't be a used entry after the first free entry. */
if( driver_table[i].lifetime == lifetime )
return( PSA_ERROR_ALREADY_EXISTS );
}
if( i == PSA_MAX_SE_DRIVERS )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
driver_table[i].lifetime = lifetime;
driver_table[i].methods = methods;
return( PSA_SUCCESS );
}
void psa_unregister_all_se_drivers( void )
{
memset( driver_table, 0, sizeof( driver_table ) );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */