mbedtls/library/psa_crypto_se.h
Gilles Peskine 8b96cad204 SE drivers: implement persistent storage
Store the persistent data of secure element drivers.

This is fully implemented, but not at all tested.
2019-07-23 17:38:08 +02:00

174 lines
6.2 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)
*/
#ifndef PSA_CRYPTO_SE_H
#define PSA_CRYPTO_SE_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "psa/crypto.h"
#include "psa/crypto_se_driver.h"
/** The maximum lifetime value that this implementation supports
* for a secure element.
*
* This is not a characteristic that each PSA implementation has, but a
* limitation of the current implementation due to the constraints imposed
* by storage. See #PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE.
*
* The minimum lifetime value for a secure element is 2, like on any
* PSA implementation (0=volatile and 1=internal-storage are taken).
*/
#define PSA_MAX_SE_LIFETIME 255
/** The base of the range of ITS file identifiers for secure element
* driver persistent data.
*
* We use a slice of the implemenation reserved range 0xffff0000..0xffffffff,
* specifically the range 0xfffffe00..0xfffffeff. The length of this range
* drives the value of #PSA_MAX_SE_LIFETIME.
* The identifiers 0xfffffe00 and 0xfffffe01 are actually not used since
* they correspond to #PSA_KEY_LIFETIME_VOLATILE and
* #PSA_KEY_LIFETIME_PERSISTENT which don't have a driver.
*/
#define PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE ( (psa_key_id_t) 0xfffffe00 )
/** The maximum number of registered secure element driver lifetimes. */
#define PSA_MAX_SE_DRIVERS 4
/** Unregister all secure element drivers.
*
* \warning Do not call this function while the library is in the initialized
* state. This function is only intended to be called at the end
* of mbedtls_psa_crypto_free().
*/
void psa_unregister_all_se_drivers( void );
/** A structure that describes a registered secure element driver.
*
* A secure element driver table entry contains a pointer to the
* driver's method table as well as the driver context structure.
*/
typedef struct psa_se_drv_table_entry_s psa_se_drv_table_entry_t;
/** Return the secure element driver information for a lifetime value.
*
* \param lifetime The lifetime value to query.
* \param[out] p_methods On output, if there is a driver,
* \c *methods points to its method table.
* Otherwise \c *methods is \c NULL.
* \param[out] p_drv_context On output, if there is a driver,
* \c *drv_context points to its context
* structure.
* Otherwise \c *drv_context is \c NULL.
*
* \retval 1
* \p lifetime corresponds to a registered driver.
* \retval 0
* \p lifetime does not correspond to a registered driver.
*/
int psa_get_se_driver( psa_key_lifetime_t lifetime,
const psa_drv_se_t **p_methods,
psa_drv_se_context_t **p_drv_context);
/** Return the secure element driver table entry for a lifetime value.
*
* \param lifetime The lifetime value to query.
*
* \return The driver table entry for \p lifetime, or
* \p NULL if \p lifetime does not correspond to a registered driver.
*/
psa_se_drv_table_entry_t *psa_get_se_driver_entry(
psa_key_lifetime_t lifetime );
/** Return the method table for a secure element driver.
*
* \param[in] driver The driver table entry to access, or \c NULL.
*
* \return The driver's method table.
* \c NULL if \p driver is \c NULL.
*/
const psa_drv_se_t *psa_get_se_driver_methods(
const psa_se_drv_table_entry_t *driver );
/** Return the context of a secure element driver.
*
* \param[in] driver The driver table entry to access, or \c NULL.
*
* \return A pointer to the driver context.
* \c NULL if \p driver is \c NULL.
*/
psa_drv_se_context_t *psa_get_se_driver_context(
psa_se_drv_table_entry_t *driver );
/** Find a free slot for a key that is to be created.
*
* This function calls the relevant method in the driver to find a suitable
* slot for a key with the given attributes.
*
* \param[in] attributes Metadata about the key that is about to be created.
* \param[in] driver The driver table entry to query.
* \param[out] slot_number On success, a slot number that is free in this
* secure element.
*/
psa_status_t psa_find_se_slot_for_key(
const psa_key_attributes_t *attributes,
psa_se_drv_table_entry_t *driver,
psa_key_slot_number_t *slot_number );
/** Destoy a key in a secure element.
*
* This function calls the relevant driver method to destroy a key
* and updates the driver's persistent data.
*/
psa_status_t psa_destroy_se_key( psa_se_drv_table_entry_t *driver,
psa_key_slot_number_t slot_number );
/** Load the persistent data of a secure element driver.
*
* \param driver The driver table entry containing the persistent
* data to load from storage.
*/
psa_status_t psa_load_se_persistent_data(
const psa_se_drv_table_entry_t *driver );
/** Save the persistent data of a secure element driver.
*
* \param[in] driver The driver table entry containing the persistent
* data to save to storage.
*/
psa_status_t psa_save_se_persistent_data(
const psa_se_drv_table_entry_t *driver );
/** Destroy the persistent data of a secure element driver.
*
* This is currently only used for testing.
*
* \param[in] lifetime The driver lifetime whose persistent data should
* be erased.
*/
psa_status_t psa_destroy_se_persistent_data( psa_key_lifetime_t lifetime );
#endif /* PSA_CRYPTO_SE_H */