mbedtls/library/psa_crypto_storage_backend.h
Gilles Peskine 5b229a06f4 Support encoding an owner in key file IDs
Differentiate between _key identifiers_, which are always `uint32_t`,
and _key file identifiers_, which are platform-dependent. Normally,
the two are the same.

In `psa/crypto_platform.h`, define `psa_app_key_id_t` (which is always
32 bits, the standard key identifier type) and
`psa_key_file_id_t` (which will be different in some service builds).
A subsequent commit will introduce a platform where the two are different.

It would make sense for the function declarations in `psa/crypto.h` to
use `psa_key_file_id_t`. However this file is currently part of the
PSA Crypto API specification, so it must stick to the standard type
`psa_key_id_t`. Hence, as long as the specification and Mbed Crypto
are not separate, use the implementation-specific file
`psa/crypto_platform.h` to define `psa_key_id_t` as `psa_key_file_id_t`.

In the library, systematically use `psa_key_file_id_t`.

    perl -i -pe 's/psa_key_id_t/psa_key_file_id_t/g' library/*.[hc]
2019-02-20 12:52:07 +01:00

115 lines
3.6 KiB
C

/**
* \file psa_crypto_storage_backend.h
*
* \brief PSA cryptography module: Mbed TLS key storage backend
*/
/*
* 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)
*/
#ifndef PSA_CRYPTO_STORAGE_BACKEND_H
#define PSA_CRYPTO_STORAGE_BACKEND_H
#ifdef __cplusplus
extern "C" {
#endif
/* Include the Mbed TLS configuration file, the way Mbed TLS does it
* in each of its header files. */
#if defined(MBEDTLS_CONFIG_FILE)
#include MBEDTLS_CONFIG_FILE
#else
#include "mbedtls/config.h"
#endif
#include "psa/crypto.h"
#include "psa_crypto_storage.h"
#include <stdint.h>
/**
* \brief Load persistent data for the given key slot number.
*
* This function reads data from a storage backend and returns the data in a
* buffer.
*
* \param key Persistent identifier of the key to be loaded. This
* should be an occupied storage location.
* \param[out] data Buffer where the data is to be written.
* \param data_size Size of the \c data buffer in bytes.
*
* \retval PSA_SUCCESS
* \retval PSA_ERROR_STORAGE_FAILURE
* \retval PSA_ERROR_DOES_NOT_EXIST
*/
psa_status_t psa_crypto_storage_load( const psa_key_file_id_t key, uint8_t *data,
size_t data_size );
/**
* \brief Store persistent data for the given key slot number.
*
* This function stores the given data buffer to a persistent storage.
*
* \param key Persistent identifier of the key to be stored. This
* should be an unoccupied storage location.
* \param[in] data Buffer containing the data to be stored.
* \param data_length The number of bytes
* that make up the data.
*
* \retval PSA_SUCCESS
* \retval PSA_ERROR_INSUFFICIENT_STORAGE
* \retval PSA_ERROR_STORAGE_FAILURE
* \retval PSA_ERROR_ALREADY_EXISTS
*/
psa_status_t psa_crypto_storage_store( const psa_key_file_id_t key,
const uint8_t *data,
size_t data_length );
/**
* \brief Checks if persistent data is stored for the given key slot number
*
* This function checks if any key data or metadata exists for the key slot in
* the persistent storage.
*
* \param key Persistent identifier to check.
*
* \retval 0
* No persistent data present for slot number
* \retval 1
* Persistent data present for slot number
*/
int psa_is_key_present_in_storage( const psa_key_file_id_t key );
/**
* \brief Get data length for given key slot number.
*
* \param key Persistent identifier whose stored data length
* is to be obtained.
* \param[out] data_length The number of bytes that make up the data.
*
* \retval PSA_SUCCESS
* \retval PSA_ERROR_STORAGE_FAILURE
*/
psa_status_t psa_crypto_storage_get_data_length( const psa_key_file_id_t key,
size_t *data_length );
#ifdef __cplusplus
}
#endif
#endif /* PSA_CRYPTO_STORAGE_H */