/* sha3.h - an implementation of Secure Hash Algorithm 3 (Keccak).
 * based on the
 * The Keccak SHA-3 submission. Submission to NIST (Round 3), 2011
 * by Guido Bertoni, Joan Daemen, Michaël Peeters and Gilles Van Assche
 *
 * Copyright: 2013 Aleksey Kravchenko <rhash.admin@gmail.com>
 *
 * Permission is hereby granted,  free of charge,  to any person  obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction,  including without limitation
 * the rights to  use, copy, modify,  merge, publish, distribute, sublicense,
 * and/or sell copies  of  the Software,  and to permit  persons  to whom the
 * Software is furnished to do so.
 *
 * This program  is  distributed  in  the  hope  that it will be useful,  but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  Use this program  at  your own risk!
 */

#ifndef RHASH_SHA3_H
#define RHASH_SHA3_H

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

#define sha3_224_hash_size  28
#define sha3_256_hash_size  32
#define sha3_384_hash_size  48
#define sha3_512_hash_size  64
#define sha3_max_permutation_size 25
#define sha3_max_rate_in_qwords 24

/**
 * SHA3 Algorithm context.
 */
typedef struct sha3_ctx
{
	/* 1600 bits algorithm hashing state */
	uint64_t hash[sha3_max_permutation_size];
	/* 1536-bit buffer for leftovers */
	uint64_t message[sha3_max_rate_in_qwords];
	/* count of bytes in the message[] buffer */
	unsigned rest;
	/* size of a message block processed at once */
	unsigned block_size;
} sha3_ctx;

/* methods for calculating the hash function */

void rhash_sha3_224_init(sha3_ctx *ctx);
void rhash_sha3_256_init(sha3_ctx *ctx);
void rhash_sha3_384_init(sha3_ctx *ctx);
void rhash_sha3_512_init(sha3_ctx *ctx);
void rhash_sha3_update(sha3_ctx *ctx, const unsigned char* msg, size_t size);
void rhash_sha3_final(sha3_ctx *ctx, unsigned char* result);

#ifdef USE_KECCAK
#define rhash_keccak_224_init rhash_sha3_224_init
#define rhash_keccak_256_init rhash_sha3_256_init
#define rhash_keccak_384_init rhash_sha3_384_init
#define rhash_keccak_512_init rhash_sha3_512_init
#define rhash_keccak_update rhash_sha3_update
void rhash_keccak_final(sha3_ctx *ctx, unsigned char* result);
#endif

#ifdef __cplusplus
} /* extern "C" */
#endif /* __cplusplus */

#endif /* RHASH_SHA3_H */