/**
 * \file sha256.h
 *
 * \brief This file contains SHA-224 and SHA-256 definitions and functions.
 *
 * The Secure Hash Algorithms 224 and 256 (SHA-224 and SHA-256) cryptographic
 * hash functions are defined in <em>FIPS 180-4: Secure Hash Standard (SHS)</em>.
 */
/*
 *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
 *  Copyright (C) 2019, STMicroelectronics, 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 implements STMicroelectronics SHA256 API with HW services based
 *  on mbed TLS API
 */

#ifndef MBEDTLS_SHA256_ALT_H
#define MBEDTLS_SHA256_ALT_H

#if defined (MBEDTLS_SHA256_ALT)
#include "stm32u5xx_hal.h"

#define ST_SHA256_BLOCK_SIZE  ((size_t)  64)        /*!< HW handles 512 bits, ie 64 bytes */
#define ST_SHA256_EXTRA_BYTES ((size_t)  4)         /*!< One supplementary word on first block */
#define ST_SHA256_NB_HASH_REG ((uint32_t)57)        /*!< Number of HASH HW context Registers:
                                                         CR + STR + IMR + CSR[54] */

/**
 * \brief          SHA-256 context structure
 *
 *                 The structure is used both for SHA-256 and for SHA-224
 *                 checksum calculations. The choice between these two is
 *                 made in the call to mbedtls_sha256_starts_ret().
 */
typedef struct mbedtls_sha256_context
{
    int is224;                                      /*!< 0 = use SHA256, 1 = use SHA224 */
    HASH_HandleTypeDef hhash;                       /*!< Handle of HASH HAL */
    uint8_t sbuf[ST_SHA256_BLOCK_SIZE + ST_SHA256_EXTRA_BYTES];
                                                    /*!< Buffer to store input data
                                                        (first block with its extra bytes,
                                                         intermediate blocks,
                                                         or last input block) */
    uint8_t sbuf_len;                               /*!< Number of bytes stored in sbuf */
    uint8_t ctx_save_regs[ST_SHA256_NB_HASH_REG*4];
    uint8_t first;                                  /*!< Extra-bytes on first computed block */
}
mbedtls_sha256_context;


#endif /* MBEDTLS_SHA256_ALT */
#endif /* MBEDTLS_SHA256_ALT_H */