Mbed OS Reference | psa_crypto

 /*
  *  PSA crypto support for secure element drivers
  */
 /*
  *  Copyright The Mbed TLS Contributors
  *  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.
  */
 
 #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 location 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 location value for a secure element is 1, like on any
  * PSA implementation (0 means a transparent key).
  */
 #define PSA_MAX_SE_LOCATION 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_LOCATION. The identifier 0xfffffe00 is
  * actually not used since it corresponds to #PSA_KEY_LOCATION_LOCAL_STORAGE
  * which doesn'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 locations. */
 #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 );
 
 /** Initialize all secure element drivers.
  *
  * Called from psa_crypto_init().
  */
 psa_status_t psa_init_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_key_creation_method_t method,
     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] location  The location identifier for the driver whose
  *                      persistent data is to be erased.
  */
 psa_status_t psa_destroy_se_persistent_data( psa_key_location_t location );
 
 
 /** The storage representation of a key whose data is in a secure element.
  */
 typedef struct
 {
     uint8_t slot_number[sizeof( psa_key_slot_number_t )];
     uint8_t bits[sizeof( psa_key_bits_t )];
 } psa_se_key_data_storage_t;
 
 #endif /* PSA_CRYPTO_SE_H */
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