313 lines
9.5 KiB
C
313 lines
9.5 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_service_integration.h"
|
|
#include "psa/crypto.h"
|
|
|
|
#include "psa_crypto_core.h"
|
|
#include "psa_crypto_slot_management.h"
|
|
#include "psa_crypto_storage.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#define mbedtls_calloc calloc
|
|
#define mbedtls_free free
|
|
#endif
|
|
|
|
#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
|
|
|
|
typedef struct
|
|
{
|
|
psa_key_slot_t key_slots[PSA_KEY_SLOT_COUNT];
|
|
unsigned key_slots_initialized : 1;
|
|
} psa_global_data_t;
|
|
|
|
static psa_global_data_t global_data;
|
|
|
|
/* Access a key slot at the given handle. The handle of a key slot is
|
|
* the index of the slot in the global slot array, plus one so that handles
|
|
* start at 1 and not 0. */
|
|
psa_status_t psa_get_key_slot( psa_key_handle_t handle,
|
|
psa_key_slot_t **p_slot )
|
|
{
|
|
psa_key_slot_t *slot = NULL;
|
|
|
|
if( ! global_data.key_slots_initialized )
|
|
return( PSA_ERROR_BAD_STATE );
|
|
|
|
/* 0 is not a valid handle under any circumstance. This
|
|
* implementation provides slots number 1 to N where N is the
|
|
* number of available slots. */
|
|
if( handle == 0 || handle > ARRAY_LENGTH( global_data.key_slots ) )
|
|
return( PSA_ERROR_INVALID_HANDLE );
|
|
slot = &global_data.key_slots[handle - 1];
|
|
|
|
/* If the slot hasn't been allocated, the handle is invalid. */
|
|
if( ! slot->allocated )
|
|
return( PSA_ERROR_INVALID_HANDLE );
|
|
|
|
*p_slot = slot;
|
|
return( PSA_SUCCESS );
|
|
}
|
|
|
|
psa_status_t psa_initialize_key_slots( void )
|
|
{
|
|
/* Nothing to do: program startup and psa_wipe_all_key_slots() both
|
|
* guarantee that the key slots are initialized to all-zero, which
|
|
* means that all the key slots are in a valid, empty state. */
|
|
global_data.key_slots_initialized = 1;
|
|
return( PSA_SUCCESS );
|
|
}
|
|
|
|
void psa_wipe_all_key_slots( void )
|
|
{
|
|
psa_key_handle_t key;
|
|
for( key = 1; key <= PSA_KEY_SLOT_COUNT; key++ )
|
|
{
|
|
psa_key_slot_t *slot = &global_data.key_slots[key - 1];
|
|
(void) psa_wipe_key_slot( slot );
|
|
}
|
|
global_data.key_slots_initialized = 0;
|
|
}
|
|
|
|
/** Find a free key slot and mark it as in use.
|
|
*
|
|
* \param[out] handle On success, a slot number that is not in use. This
|
|
* value can be used as a handle to the slot.
|
|
*
|
|
* \retval #PSA_SUCCESS
|
|
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
|
|
*/
|
|
static psa_status_t psa_internal_allocate_key_slot( psa_key_handle_t *handle )
|
|
{
|
|
for( *handle = PSA_KEY_SLOT_COUNT; *handle != 0; --( *handle ) )
|
|
{
|
|
psa_key_slot_t *slot = &global_data.key_slots[*handle - 1];
|
|
if( ! slot->allocated )
|
|
{
|
|
slot->allocated = 1;
|
|
return( PSA_SUCCESS );
|
|
}
|
|
}
|
|
return( PSA_ERROR_INSUFFICIENT_MEMORY );
|
|
}
|
|
|
|
/** Wipe a key slot and mark it as available.
|
|
*
|
|
* This does not affect persistent storage.
|
|
*
|
|
* \param handle The handle to the key slot to release.
|
|
*
|
|
* \retval #PSA_SUCCESS
|
|
* \retval #PSA_ERROR_INVALID_ARGUMENT
|
|
* \retval #PSA_ERROR_TAMPERING_DETECTED
|
|
*/
|
|
static psa_status_t psa_internal_release_key_slot( psa_key_handle_t handle )
|
|
{
|
|
psa_key_slot_t *slot;
|
|
psa_status_t status;
|
|
|
|
status = psa_get_key_slot( handle, &slot );
|
|
if( status != PSA_SUCCESS )
|
|
return( status );
|
|
|
|
return( psa_wipe_key_slot( slot ) );
|
|
}
|
|
|
|
psa_status_t psa_allocate_key( psa_key_handle_t *handle )
|
|
{
|
|
*handle = 0;
|
|
return( psa_internal_allocate_key_slot( handle ) );
|
|
}
|
|
|
|
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
|
|
static psa_status_t psa_load_persistent_key_into_slot( psa_key_slot_t *p_slot )
|
|
{
|
|
psa_status_t status = PSA_SUCCESS;
|
|
uint8_t *key_data = NULL;
|
|
size_t key_data_length = 0;
|
|
|
|
status = psa_load_persistent_key( p_slot->persistent_storage_id,
|
|
&( p_slot )->type,
|
|
&( p_slot )->policy, &key_data,
|
|
&key_data_length );
|
|
if( status != PSA_SUCCESS )
|
|
goto exit;
|
|
status = psa_import_key_into_slot( p_slot,
|
|
key_data, key_data_length );
|
|
exit:
|
|
psa_free_persistent_key_data( key_data, key_data_length );
|
|
return( status );
|
|
}
|
|
|
|
/** Check whether a key identifier is acceptable.
|
|
*
|
|
* For backward compatibility, key identifiers that were valid in a
|
|
* past released version must remain valid, unless a migration path
|
|
* is provided.
|
|
*
|
|
* \param file_id The key identifier to check.
|
|
* \param vendor_ok Nonzero to allow key ids in the vendor range.
|
|
* 0 to allow only key ids in the application range.
|
|
*
|
|
* \return 1 if \p file_id is acceptable, otherwise 0.
|
|
*/
|
|
static int psa_is_key_id_valid( psa_key_file_id_t file_id,
|
|
int vendor_ok )
|
|
{
|
|
psa_app_key_id_t key_id = PSA_KEY_FILE_GET_KEY_ID( file_id );
|
|
if( PSA_KEY_ID_USER_MIN <= key_id && key_id <= PSA_KEY_ID_USER_MAX )
|
|
return( 1 );
|
|
else if( vendor_ok &&
|
|
PSA_KEY_ID_VENDOR_MIN <= key_id &&
|
|
key_id <= PSA_KEY_ID_VENDOR_MAX )
|
|
return( 1 );
|
|
else
|
|
return( 0 );
|
|
}
|
|
|
|
/** Declare a slot as persistent and load it from storage.
|
|
*
|
|
* This function may only be called immediately after a successful call
|
|
* to psa_internal_allocate_key_slot().
|
|
*
|
|
* \param handle A handle to a key slot freshly allocated with
|
|
* psa_internal_allocate_key_slot().
|
|
*
|
|
* \retval #PSA_SUCCESS
|
|
* The slot content was loaded successfully.
|
|
* \retval #PSA_ERROR_DOES_NOT_EXIST
|
|
* There is no content for this slot in persistent storage.
|
|
* \retval #PSA_ERROR_INVALID_HANDLE
|
|
* \retval #PSA_ERROR_INVALID_ARGUMENT
|
|
* \p id is not acceptable.
|
|
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
|
|
* \retval #PSA_ERROR_STORAGE_FAILURE
|
|
*/
|
|
static psa_status_t psa_internal_make_key_persistent( psa_key_handle_t handle,
|
|
psa_key_file_id_t id )
|
|
{
|
|
psa_key_slot_t *slot;
|
|
psa_status_t status;
|
|
|
|
status = psa_get_key_slot( handle, &slot );
|
|
if( status != PSA_SUCCESS )
|
|
return( status );
|
|
|
|
slot->lifetime = PSA_KEY_LIFETIME_PERSISTENT;
|
|
slot->persistent_storage_id = id;
|
|
status = psa_load_persistent_key_into_slot( slot );
|
|
|
|
return( status );
|
|
}
|
|
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
|
|
|
|
psa_status_t psa_validate_persistent_key_parameters(
|
|
psa_key_lifetime_t lifetime,
|
|
psa_key_file_id_t id,
|
|
int creating )
|
|
{
|
|
if( lifetime != PSA_KEY_LIFETIME_PERSISTENT )
|
|
return( PSA_ERROR_INVALID_ARGUMENT );
|
|
|
|
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
|
|
if( ! psa_is_key_id_valid( id, ! creating ) )
|
|
return( PSA_ERROR_INVALID_ARGUMENT );
|
|
return( PSA_SUCCESS );
|
|
|
|
#else /* MBEDTLS_PSA_CRYPTO_STORAGE_C */
|
|
(void) id;
|
|
(void) creating;
|
|
return( PSA_ERROR_NOT_SUPPORTED );
|
|
#endif /* !MBEDTLS_PSA_CRYPTO_STORAGE_C */
|
|
}
|
|
|
|
static psa_status_t persistent_key_setup( psa_key_lifetime_t lifetime,
|
|
psa_key_file_id_t id,
|
|
psa_key_handle_t *handle,
|
|
int creating )
|
|
{
|
|
psa_status_t status;
|
|
psa_status_t wanted_load_status =
|
|
( creating ? PSA_ERROR_DOES_NOT_EXIST : PSA_SUCCESS );
|
|
|
|
*handle = 0;
|
|
|
|
status = psa_validate_persistent_key_parameters( lifetime, id, creating );
|
|
if( status != PSA_SUCCESS )
|
|
return( status );
|
|
|
|
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
|
|
status = psa_internal_allocate_key_slot( handle );
|
|
if( status != PSA_SUCCESS )
|
|
return( status );
|
|
|
|
status = psa_internal_make_key_persistent( *handle, id );
|
|
if( status != wanted_load_status )
|
|
{
|
|
psa_internal_release_key_slot( *handle );
|
|
*handle = 0;
|
|
}
|
|
return( status );
|
|
#else /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
|
|
(void) wanted_load_status;
|
|
return( PSA_ERROR_NOT_SUPPORTED );
|
|
#endif /* !defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
|
|
}
|
|
|
|
psa_status_t psa_open_key( psa_key_file_id_t id, psa_key_handle_t *handle )
|
|
{
|
|
return( persistent_key_setup( PSA_KEY_LIFETIME_PERSISTENT,
|
|
id, handle, 0 ) );
|
|
}
|
|
|
|
psa_status_t psa_create_key( psa_key_lifetime_t lifetime,
|
|
psa_key_file_id_t id,
|
|
psa_key_handle_t *handle )
|
|
{
|
|
psa_status_t status;
|
|
|
|
status = persistent_key_setup( lifetime, id, handle, 1 );
|
|
switch( status )
|
|
{
|
|
case PSA_SUCCESS: return( PSA_ERROR_ALREADY_EXISTS );
|
|
case PSA_ERROR_DOES_NOT_EXIST: return( PSA_SUCCESS );
|
|
default: return( status );
|
|
}
|
|
}
|
|
|
|
psa_status_t psa_close_key( psa_key_handle_t handle )
|
|
{
|
|
return( psa_internal_release_key_slot( handle ) );
|
|
}
|
|
|
|
#endif /* MBEDTLS_PSA_CRYPTO_C */
|