/*
* Copyright (C) 2012-2019 UCloud. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* or in the "license" file accompanying this file. This file 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 _UTILS_SHA2_H
#define _UTILS_SHA2_H

#include <stdint.h>

#define SHA256_DIGEST_LENGTH            (32)
#define SHA256_BLOCK_LENGTH             (64)
#define SHA256_SHORT_BLOCK_LENGTH       (SHA256_BLOCK_LENGTH - 8)
#define SHA256_DIGEST_STRING_LENGTH     (SHA256_DIGEST_LENGTH * 2 + 1)

/**
 * \brief          SHA-256 context structure
 */
typedef struct {
    uint32_t total[2];          /*!< number of bytes processed  */
    uint32_t state[8];          /*!< intermediate digest state  */
    unsigned char buffer[64];   /*!< data block being processed */
    int is224;                  /*!< 0 => SHA-256, else SHA-224 */
} iot_sha256_context;

typedef union {
    char sptr[8];
    uint64_t lint;
} u_retLen;

/**
 * \brief          Initialize SHA-256 context
 *
 * \param ctx      SHA-256 context to be initialized
 */
void utils_sha256_init(iot_sha256_context *ctx);

/**
 * \brief          Clear SHA-256 context
 *
 * \param ctx      SHA-256 context to be cleared
 */
void utils_sha256_free(iot_sha256_context *ctx);


/**
 * \brief          SHA-256 context setup
 *
 * \param ctx      context to be initialized
 */
void utils_sha256_starts(iot_sha256_context *ctx);

/**
 * \brief          SHA-256 process buffer
 *
 * \param ctx      SHA-256 context
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 */
void utils_sha256_update(iot_sha256_context *ctx, const unsigned char *input, uint32_t ilen);

/**
 * \brief          SHA-256 final digest
 *
 * \param ctx      SHA-256 context
 * \param output   SHA-256 checksum result
 */
void utils_sha256_finish(iot_sha256_context *ctx, uint8_t output[32]);

/* Internal use */
void utils_sha256_process(iot_sha256_context *ctx, const unsigned char data[64]);

/**
 * \brief          Output = SHA-256( input buffer )
 *
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 * \param output   SHA-256 checksum result
 */
void utils_sha256(const uint8_t *input, uint32_t ilen, uint8_t output[32]);

void utils_hmac_sha256(const uint8_t *msg, uint32_t msg_len, const uint8_t *key, uint32_t key_len, uint8_t output[32]);

#ifdef __cplusplus
}
#endif

#endif