/*
 * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Hyra nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _CRYPTO_SHA256_H
#define _CRYPTO_SHA256_H 1

#include <stddef.h>
#include <stdint.h>

#define SHA256_HEX_SIZE (64 + 1)
#define SHA256_BYTES_SIZE 32

/*
 * Compute the SHA-256 checksum of a memory region given a pointer and
 * the size of that memory region.
 * The output is a hexadecimal string of 65 characters.
 * The last character will be the null-character.
 */
void sha256_hex(const void *src, size_t n_bytes, char *dst_hex65);

void sha256_bytes(const void *src, size_t n_bytes, void *dst_bytes32);

typedef struct sha256 {
    uint32_t state[8];
    uint8_t buffer[64];
    uint64_t n_bits;
    uint8_t buffer_counter;
} sha256;

/* Functions to compute streaming SHA-256 checksums. */
void sha256_init(struct sha256 *sha);
void sha256_append(struct sha256 *sha, const void *data, size_t n_bytes);
void sha256_finalize_hex(struct sha256 *sha, char *dst_hex65);
void sha256_finalize_bytes(struct sha256 *sha, void *dst_bytes32);

#endif  /* !_CRYPTO_SHA256_H */