/* 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 __SHA3_H__
#define __SHA3_H__

#include <stdint.h>
#include "options.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

#define SHA3_224_BLOCK_LENGTH 144
#define SHA3_256_BLOCK_LENGTH 136
#define SHA3_384_BLOCK_LENGTH 104
#define SHA3_512_BLOCK_LENGTH 72

#define SHA3_224_DIGEST_LENGTH sha3_224_hash_size
#define SHA3_256_DIGEST_LENGTH sha3_256_hash_size
#define SHA3_384_DIGEST_LENGTH sha3_384_hash_size
#define SHA3_512_DIGEST_LENGTH sha3_512_hash_size

/**
 * 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 sha3_224_Init(SHA3_CTX* ctx);
void sha3_256_Init(SHA3_CTX* ctx);
void sha3_384_Init(SHA3_CTX* ctx);
void sha3_512_Init(SHA3_CTX* ctx);
void sha3_Update(SHA3_CTX* ctx, const unsigned char* msg, size_t size);
void sha3_Final(SHA3_CTX* ctx, unsigned char* result);

#if USE_KECCAK
#define keccak_224_Init sha3_224_Init
#define keccak_256_Init sha3_256_Init
#define keccak_384_Init sha3_384_Init
#define keccak_512_Init sha3_512_Init
#define keccak_Update sha3_Update
void keccak_Final(SHA3_CTX* ctx, unsigned char* result);
void keccak_256(const unsigned char* data, size_t len, unsigned char* digest);
void keccak_512(const unsigned char* data, size_t len, unsigned char* digest);
#endif

void sha3_256(const unsigned char* data, size_t len, unsigned char* digest);
void sha3_512(const unsigned char* data, size_t len, unsigned char* digest);

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

#endif /* __SHA3_H__ */
