mbedtls/library/psa_crypto_core.h
Ronald Cron 19daca9b2e Prefer persistent over permanent
For consistency across the code base, prefer
persistent over permanent to qualify a key
stored in persistent storage.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2020-11-11 15:12:16 +01:00

214 lines
6.7 KiB
C

/*
* PSA crypto core internal interfaces
*/
/*
* 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_CORE_H
#define PSA_CRYPTO_CORE_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 data structure representing a key slot, containing key material
* and metadata for one key.
*/
typedef struct
{
psa_core_key_attributes_t attr;
/*
* Number of on-going accesses, read and/or write, to the key slot by the
* library.
*
* This counter is incremented by one each time a library function
* retrieves through one of the dedicated internal API a pointer to the
* key slot.
*
* This counter is decremented by one each time a library function stops
* accessing to the key slot and states it by calling the
* psa_decrement_key_slot_access_count() API.
*
* This counter is used to prevent resetting the key slot while the library
* may access it. For example, such control is needed in the following
* scenarios:
* . In case of key slot starvation, all key slots contain the description
* of a key, and the library asks for the description of a persistent
* key not present in the key slots, the key slots currently accessed by
* the library cannot be reclaimed to free a key slot to load the
* persistent key.
* . In case of a multi-threaded application where one thread asks to close
* or purge or destroy a key while it is in used by the library through
* another thread.
*/
size_t access_count;
union
{
/* Dynamically allocated key data buffer.
* Format as specified in psa_export_key(). */
struct key_data
{
uint8_t *data;
size_t bytes;
} key;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Any key type in a secure element */
struct se
{
psa_key_slot_number_t slot_number;
} se;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
} data;
} psa_key_slot_t;
/* A mask of key attribute flags used only internally.
* Currently there aren't any. */
#define PSA_KA_MASK_INTERNAL_ONLY ( \
0 )
/** Test whether a key slot is occupied.
*
* A key slot is occupied iff the key type is nonzero. This works because
* no valid key can have 0 as its key type.
*
* \param[in] slot The key slot to test.
*
* \return 1 if the slot is occupied, 0 otherwise.
*/
static inline int psa_is_key_slot_occupied( const psa_key_slot_t *slot )
{
return( slot->attr.type != 0 );
}
/** Test whether a key slot is accessed.
*
* A key slot is accessed iff its access counter is strickly greater than
* 0.
*
* \param[in] slot The key slot to test.
*
* \return 1 if the slot is accessed, 0 otherwise.
*/
static inline int psa_is_key_slot_accessed( const psa_key_slot_t *slot )
{
return( slot->access_count > 0 );
}
/** Retrieve flags from psa_key_slot_t::attr::core::flags.
*
* \param[in] slot The key slot to query.
* \param mask The mask of bits to extract.
*
* \return The key attribute flags in the given slot,
* bitwise-anded with \p mask.
*/
static inline uint16_t psa_key_slot_get_flags( const psa_key_slot_t *slot,
uint16_t mask )
{
return( slot->attr.flags & mask );
}
/** Set flags in psa_key_slot_t::attr::core::flags.
*
* \param[in,out] slot The key slot to modify.
* \param mask The mask of bits to modify.
* \param value The new value of the selected bits.
*/
static inline void psa_key_slot_set_flags( psa_key_slot_t *slot,
uint16_t mask,
uint16_t value )
{
slot->attr.flags = ( ( ~mask & slot->attr.flags ) |
( mask & value ) );
}
/** Turn on flags in psa_key_slot_t::attr::core::flags.
*
* \param[in,out] slot The key slot to modify.
* \param mask The mask of bits to set.
*/
static inline void psa_key_slot_set_bits_in_flags( psa_key_slot_t *slot,
uint16_t mask )
{
slot->attr.flags |= mask;
}
/** Turn off flags in psa_key_slot_t::attr::core::flags.
*
* \param[in,out] slot The key slot to modify.
* \param mask The mask of bits to clear.
*/
static inline void psa_key_slot_clear_bits( psa_key_slot_t *slot,
uint16_t mask )
{
slot->attr.flags &= ~mask;
}
/** Completely wipe a slot in memory, including its policy.
*
* Persistent storage is not affected.
*
* \param[in,out] slot The key slot to wipe.
*
* \retval #PSA_SUCCESS
* Success. This includes the case of a key slot that was
* already fully wiped.
* \retval #PSA_ERROR_CORRUPTION_DETECTED
*/
psa_status_t psa_wipe_key_slot( psa_key_slot_t *slot );
/** Copy key data (in export format) into an empty key slot.
*
* This function assumes that the slot does not contain
* any key material yet. On failure, the slot content is unchanged.
*
* \param[in,out] slot Key slot to copy the key into.
* \param[in] data Buffer containing the key material.
* \param data_length Size of the key buffer.
*
* \retval #PSA_SUCCESS
* The key has been copied successfully.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* Not enough memory was available for allocation of the
* copy buffer.
* \retval #PSA_ERROR_ALREADY_EXISTS
* There was other key material already present in the slot.
*/
psa_status_t psa_copy_key_material_into_slot( psa_key_slot_t *slot,
const uint8_t *data,
size_t data_length );
/** Convert an mbed TLS error code to a PSA error code
*
* \note This function is provided solely for the convenience of
* Mbed TLS and may be removed at any time without notice.
*
* \param ret An mbed TLS-thrown error code
*
* \return The corresponding PSA error code
*/
psa_status_t mbedtls_to_psa_error( int ret );
#endif /* PSA_CRYPTO_CORE_H */