db2b8db715
Add new functions, psa_load_persistent_key(), psa_free_persistent_key_data(), and psa_save_persistent_key(), for managing persistent keys. These functions load to or save from our internal representation of key slots. Serialization is a concern of the storage backend implementation and doesn't abstraction-leak into the lifetime management code. An initial implementation for files is provided. Additional storage backends can implement this interface for other storage types.
178 lines
6.9 KiB
C
178 lines
6.9 KiB
C
/**
|
|
* \file psa_crypto_storage.h
|
|
*
|
|
* \brief PSA cryptography module: Mbed TLS 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)
|
|
*/
|
|
|
|
#ifndef PSA_CRYPTO_STORAGE_H
|
|
#define PSA_CRYPTO_STORAGE_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 <stdint.h>
|
|
|
|
/* Limit the maximum key size to 30kB (just in case someone tries to
|
|
* inadvertently store an obscene amount of data) */
|
|
#define PSA_CRYPTO_MAX_STORAGE_SIZE ( 30 * 1024 )
|
|
|
|
/**
|
|
* \brief Format key data and metadata and save to a location for given key
|
|
* slot.
|
|
*
|
|
* This function formats the key data and metadata and saves it to a
|
|
* persistent storage backend. The storage location corresponding to the
|
|
* key slot must be empty, otherwise this function will fail. This function
|
|
* should be called after psa_import_key_into_slot() to ensure the
|
|
* persistent key is not saved into a storage location corresponding to an
|
|
* already occupied non-persistent key, as well as validating the key data.
|
|
*
|
|
*
|
|
* \param key Slot number of the key to be stored. This must be a
|
|
* valid slot for a key of the chosen type. This should be
|
|
* an occupied key slot with an unoccupied corresponding
|
|
* storage location.
|
|
* \param type Key type (a \c PSA_KEY_TYPE_XXX value).
|
|
* \param[in] policy The key policy to save.
|
|
* \param[in] data Buffer containing the key data.
|
|
* \param data_length The number of bytes that make up the key data.
|
|
*
|
|
* \retval PSA_SUCCESS
|
|
* \retval PSA_ERROR_INSUFFICIENT_STORAGE
|
|
* \retval PSA_ERROR_STORAGE_FAILURE
|
|
*/
|
|
psa_status_t psa_save_persistent_key( const psa_key_slot_t key,
|
|
const psa_key_type_t type,
|
|
const psa_key_policy_t *policy,
|
|
const uint8_t *data,
|
|
const size_t data_length );
|
|
|
|
/**
|
|
* \brief Parses key data and metadata and load persistent key for given
|
|
* key slot number.
|
|
*
|
|
* This function reads from a storage backend, parses the key data and
|
|
* metadata and writes them to the appropriate output parameters.
|
|
*
|
|
* Note: This function allocates a buffer and returns a pointer to it through
|
|
* the data parameter. psa_free_persistent_key_data() must be called after
|
|
* this function to zeroize and free this buffer, regardless of whether this
|
|
* function succeeds or fails.
|
|
*
|
|
* \param key Slot number whose content is to be loaded. This
|
|
* must be an unoccupied key slot with an occupied
|
|
* corresponding storage location. The key slot
|
|
* lifetime must be set to persistent.
|
|
* \param[out] type On success, the key type (a \c PSA_KEY_TYPE_XXX
|
|
* value).
|
|
* \param[out] policy On success, the key's policy.
|
|
* \param[out] data Pointer to an allocated key data buffer on return.
|
|
* \param[out] data_length The number of bytes that make up the key data.
|
|
*
|
|
* \retval PSA_SUCCESS
|
|
* \retval PSA_ERROR_INSUFFICIENT_MEMORY
|
|
* \retval PSA_ERROR_STORAGE_FAILURE
|
|
*/
|
|
psa_status_t psa_load_persistent_key( psa_key_slot_t key,
|
|
psa_key_type_t *type,
|
|
psa_key_policy_t *policy,
|
|
uint8_t **data,
|
|
size_t *data_length );
|
|
|
|
/**
|
|
* \brief Remove persistent data for the given key slot number.
|
|
*
|
|
* \param key Slot number whose content is to be removed
|
|
* from persistent storage.
|
|
*
|
|
* \retval PSA_SUCCESS
|
|
* \retval PSA_ERROR_STORAGE_FAILURE
|
|
*/
|
|
psa_status_t psa_destroy_persistent_key( const psa_key_slot_t key );
|
|
|
|
/**
|
|
* \brief Zeroizes and frees the given buffer.
|
|
*
|
|
* This function must be called at some point after psa_load_persistent_key()
|
|
* to zeroize and free the memory allocated to the buffer in that function.
|
|
*
|
|
* \param key_data Buffer for the key data.
|
|
* \param key_data_length Size of the key data buffer.
|
|
*
|
|
*/
|
|
void psa_free_persistent_key_data( uint8_t *key_data, size_t key_data_length );
|
|
|
|
/**
|
|
* \brief Formats key data and metadata for persistent storage
|
|
*
|
|
* \param[in] data Buffer for the key data.
|
|
* \param data_length Length of the key data buffer.
|
|
* \param type Key type (a \c PSA_KEY_TYPE_XXX value).
|
|
* \param policy The key policy.
|
|
* \param[out] storage_data Output buffer for the formatted data.
|
|
*
|
|
*/
|
|
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 );
|
|
|
|
/**
|
|
* \brief Parses persistent storage data into key data and metadata
|
|
*
|
|
* \param[in] storage_data Buffer for the storage data.
|
|
* \param storage_data_length Length of the storage data buffer
|
|
* \param[out] key_data On output, pointer to a newly allocated buffer
|
|
* containing the key data. This must be freed
|
|
* using psa_free_persistent_key_data()
|
|
* \param[out] key_data_length Length of the key data buffer
|
|
* \param[out] type Key type (a \c PSA_KEY_TYPE_XXX value).
|
|
* \param[out] policy The key policy.
|
|
*
|
|
* \retval PSA_SUCCESS
|
|
* \retval PSA_ERROR_INSUFFICIENT_STORAGE
|
|
* \retval PSA_ERROR_INSUFFICIENT_MEMORY
|
|
* \retval PSA_ERROR_STORAGE_FAILURE
|
|
*/
|
|
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 );
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* PSA_CRYPTO_STORAGE_H */
|