/*
 *  PSA crypto core internal interfaces
 */
/*
 *  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_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;
    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 );
}

/** 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 );

/** Import key data into a slot.
 *
 * `slot->type` must have been set previously.
 * This function assumes that the slot does not contain any key material yet.
 * On failure, the slot content is unchanged.
 *
 * Persistent storage is not affected.
 *
 * \param[in,out] slot  The key slot to import data into.
 *                      Its `type` field must have previously been set to
 *                      the desired key type.
 *                      It must not contain any key material yet.
 * \param[in] data      Buffer containing the key material to parse and import.
 * \param data_length   Size of \p data in bytes.
 *
 * \retval PSA_SUCCESS
 * \retval PSA_ERROR_INVALID_ARGUMENT
 * \retval PSA_ERROR_NOT_SUPPORTED
 * \retval PSA_ERROR_INSUFFICIENT_MEMORY
 */
psa_status_t psa_import_key_into_slot( psa_key_slot_t *slot,
                                       const uint8_t *data,
                                       size_t data_length );

#endif /* PSA_CRYPTO_CORE_H */