mbedtls/library/psa_crypto_storage.c
Gilles Peskine 088b77f39c Merge psa_crypto_storage_its into psa_crypto_storage
Since the ITS API has stabilized and we don't plan to make use of more
than ITS, we don't need an abstraction layer between key storage and
key storage over ITS. Merge the ITS code into the generic storage
module.
2019-03-15 11:15:01 +01:00

354 lines
12 KiB
C

/*
* PSA persistent key storage
*/
/* 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_FILE
#else
#include "mbedtls/config.h"
#endif
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
#include <stdlib.h>
#include <string.h>
#include "psa_crypto_service_integration.h"
#include "psa/crypto.h"
#include "psa_crypto_storage.h"
#include "psa_crypto_storage_backend.h"
#include "mbedtls/platform_util.h"
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#if defined(MBEDTLS_PSA_ITS_FILE_C)
#include "psa_crypto_its.h"
#else /* Native ITS implementation */
#include "psa/error.h"
#include "psa_crypto_service_integration.h"
#include "psa/internal_trusted_storage.h"
#endif
/* Determine a file name (ITS file identifier) for the given key file
* identifier. The file name must be distinct from any file that is used
* for a purpose other than storing a key. Currently, the only such file
* is the random seed file whose name is PSA_CRYPTO_ITS_RANDOM_SEED_UID
* and whose value is 0xFFFFFF52. */
static psa_storage_uid_t psa_its_identifier_of_slot( psa_key_file_id_t file_id )
{
#if defined(MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER) && \
defined(PSA_CRYPTO_SECURE)
/* Encode the owner in the upper 32 bits. This means that if
* owner values are nonzero (as they are on a PSA platform),
* no key file will ever have a value less than 0x100000000, so
* the whole range 0..0xffffffff is available for non-key files. */
uint32_t unsigned_owner = (uint32_t) file_id.owner;
return( (uint64_t) unsigned_owner << 32 | file_id.key_id );
#else
/* Use the key id directly as a file name.
* psa_is_key_file_id_valid() in psa_crypto_slot_management.c
* is responsible for ensuring that key identifiers do not have a
* value that is reserved for non-key files. */
return( file_id );
#endif
}
psa_status_t psa_crypto_storage_load( const psa_key_file_id_t key, uint8_t *data,
size_t data_size )
{
psa_status_t status;
psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
struct psa_storage_info_t data_identifier_info;
status = psa_its_get_info( data_identifier, &data_identifier_info );
if( status != PSA_SUCCESS )
return( status );
status = psa_its_get( data_identifier, 0, data_size, data );
return( status );
}
int psa_is_key_present_in_storage( const psa_key_file_id_t key )
{
psa_status_t ret;
psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
struct psa_storage_info_t data_identifier_info;
ret = psa_its_get_info( data_identifier, &data_identifier_info );
if( ret == PSA_ERROR_DOES_NOT_EXIST )
return( 0 );
return( 1 );
}
psa_status_t psa_crypto_storage_store( const psa_key_file_id_t key,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
struct psa_storage_info_t data_identifier_info;
if( psa_is_key_present_in_storage( key ) == 1 )
return( PSA_ERROR_ALREADY_EXISTS );
status = psa_its_set( data_identifier, data_length, data, 0 );
if( status != PSA_SUCCESS )
{
return( PSA_ERROR_STORAGE_FAILURE );
}
status = psa_its_get_info( data_identifier, &data_identifier_info );
if( status != PSA_SUCCESS )
{
goto exit;
}
if( data_identifier_info.size != data_length )
{
status = PSA_ERROR_STORAGE_FAILURE;
goto exit;
}
exit:
if( status != PSA_SUCCESS )
psa_its_remove( data_identifier );
return( status );
}
psa_status_t psa_destroy_persistent_key( const psa_key_file_id_t key )
{
psa_status_t ret;
psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
struct psa_storage_info_t data_identifier_info;
ret = psa_its_get_info( data_identifier, &data_identifier_info );
if( ret == PSA_ERROR_DOES_NOT_EXIST )
return( PSA_SUCCESS );
if( psa_its_remove( data_identifier ) != PSA_SUCCESS )
return( PSA_ERROR_STORAGE_FAILURE );
ret = psa_its_get_info( data_identifier, &data_identifier_info );
if( ret != PSA_ERROR_DOES_NOT_EXIST )
return( PSA_ERROR_STORAGE_FAILURE );
return( PSA_SUCCESS );
}
psa_status_t psa_crypto_storage_get_data_length( const psa_key_file_id_t key,
size_t *data_length )
{
psa_status_t status;
psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
struct psa_storage_info_t data_identifier_info;
status = psa_its_get_info( data_identifier, &data_identifier_info );
if( status != PSA_SUCCESS )
return( status );
*data_length = (size_t) data_identifier_info.size;
return( PSA_SUCCESS );
}
/*
* 32-bit integer manipulation macros (little endian)
*/
#ifndef GET_UINT32_LE
#define GET_UINT32_LE(n,b,i) \
{ \
(n) = ( (uint32_t) (b)[(i) ] ) \
| ( (uint32_t) (b)[(i) + 1] << 8 ) \
| ( (uint32_t) (b)[(i) + 2] << 16 ) \
| ( (uint32_t) (b)[(i) + 3] << 24 ); \
}
#endif
#ifndef PUT_UINT32_LE
#define PUT_UINT32_LE(n,b,i) \
{ \
(b)[(i) ] = (unsigned char) ( ( (n) ) & 0xFF ); \
(b)[(i) + 1] = (unsigned char) ( ( (n) >> 8 ) & 0xFF ); \
(b)[(i) + 2] = (unsigned char) ( ( (n) >> 16 ) & 0xFF ); \
(b)[(i) + 3] = (unsigned char) ( ( (n) >> 24 ) & 0xFF ); \
}
#endif
/**
* Persistent key storage magic header.
*/
#define PSA_KEY_STORAGE_MAGIC_HEADER "PSA\0KEY"
#define PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH ( sizeof( PSA_KEY_STORAGE_MAGIC_HEADER ) )
typedef struct {
uint8_t magic[PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH];
uint8_t version[4];
uint8_t type[sizeof( psa_key_type_t )];
uint8_t policy[sizeof( psa_key_policy_t )];
uint8_t data_len[4];
uint8_t key_data[];
} psa_persistent_key_storage_format;
void psa_format_key_data_for_storage( const uint8_t *data,
const size_t data_length,
const psa_key_type_t type,
const psa_key_policy_t *policy,
uint8_t *storage_data )
{
psa_persistent_key_storage_format *storage_format =
(psa_persistent_key_storage_format *) storage_data;
memcpy( storage_format->magic, PSA_KEY_STORAGE_MAGIC_HEADER, PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH );
PUT_UINT32_LE(0, storage_format->version, 0);
PUT_UINT32_LE(type, storage_format->type, 0);
PUT_UINT32_LE(policy->usage, storage_format->policy, 0);
PUT_UINT32_LE(policy->alg, storage_format->policy, sizeof( uint32_t ));
PUT_UINT32_LE(data_length, storage_format->data_len, 0);
memcpy( storage_format->key_data, data, data_length );
}
static psa_status_t check_magic_header( const uint8_t *data )
{
if( memcmp( data, PSA_KEY_STORAGE_MAGIC_HEADER,
PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH ) != 0 )
return( PSA_ERROR_STORAGE_FAILURE );
return( PSA_SUCCESS );
}
psa_status_t psa_parse_key_data_from_storage( const uint8_t *storage_data,
size_t storage_data_length,
uint8_t **key_data,
size_t *key_data_length,
psa_key_type_t *type,
psa_key_policy_t *policy )
{
psa_status_t status;
const psa_persistent_key_storage_format *storage_format =
(const psa_persistent_key_storage_format *)storage_data;
uint32_t version;
if( storage_data_length < sizeof(*storage_format) )
return( PSA_ERROR_STORAGE_FAILURE );
status = check_magic_header( storage_data );
if( status != PSA_SUCCESS )
return( status );
GET_UINT32_LE(version, storage_format->version, 0);
if( version != 0 )
return( PSA_ERROR_STORAGE_FAILURE );
GET_UINT32_LE(*key_data_length, storage_format->data_len, 0);
if( *key_data_length > ( storage_data_length - sizeof(*storage_format) ) ||
*key_data_length > PSA_CRYPTO_MAX_STORAGE_SIZE )
return( PSA_ERROR_STORAGE_FAILURE );
*key_data = mbedtls_calloc( 1, *key_data_length );
if( *key_data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
GET_UINT32_LE(*type, storage_format->type, 0);
GET_UINT32_LE(policy->usage, storage_format->policy, 0);
GET_UINT32_LE(policy->alg, storage_format->policy, sizeof( uint32_t ));
memcpy( *key_data, storage_format->key_data, *key_data_length );
return( PSA_SUCCESS );
}
psa_status_t psa_save_persistent_key( const psa_key_file_id_t key,
const psa_key_type_t type,
const psa_key_policy_t *policy,
const uint8_t *data,
const size_t data_length )
{
size_t storage_data_length;
uint8_t *storage_data;
psa_status_t status;
if( data_length > PSA_CRYPTO_MAX_STORAGE_SIZE )
return PSA_ERROR_INSUFFICIENT_STORAGE;
storage_data_length = data_length + sizeof( psa_persistent_key_storage_format );
storage_data = mbedtls_calloc( 1, storage_data_length );
if( storage_data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
psa_format_key_data_for_storage( data, data_length, type, policy,
storage_data );
status = psa_crypto_storage_store( key,
storage_data, storage_data_length );
mbedtls_free( storage_data );
return( status );
}
void psa_free_persistent_key_data( uint8_t *key_data, size_t key_data_length )
{
if( key_data != NULL )
{
mbedtls_platform_zeroize( key_data, key_data_length );
}
mbedtls_free( key_data );
}
psa_status_t psa_load_persistent_key( psa_key_file_id_t key,
psa_key_type_t *type,
psa_key_policy_t *policy,
uint8_t **data,
size_t *data_length )
{
psa_status_t status = PSA_SUCCESS;
uint8_t *loaded_data;
size_t storage_data_length = 0;
status = psa_crypto_storage_get_data_length( key, &storage_data_length );
if( status != PSA_SUCCESS )
return( status );
loaded_data = mbedtls_calloc( 1, storage_data_length );
if( loaded_data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_crypto_storage_load( key, loaded_data, storage_data_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_parse_key_data_from_storage( loaded_data, storage_data_length,
data, data_length, type, policy );
exit:
mbedtls_free( loaded_data );
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C */