/*
* Copyright (C) 2013, 2014 Giorgio Vazzana
*
* This file is part of Seren.
*
* Seren is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Seren 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TWOFISH_H
#define TWOFISH_H
#include <stddef.h>
#include <stdint.h>
struct twofish_ctx {
/* 128-bit, 192-bit or 256-bit key, max 32 bytes.
Keys of any length from 8 to 256 bits, multiple of 8 bits,
can be used. They will be padded with zeroes until the next
larger defined key length. */
uint8_t key[32];
size_t keylen; /* in bits */
/* subkeys */
uint32_t K[40];
/* s-boxes */
#if 0
uint8_t S0[256];
uint8_t S1[256];
uint8_t S2[256];
uint8_t S3[256];
#else
uint32_t SF0[256];
uint32_t SF1[256];
uint32_t SF2[256];
uint32_t SF3[256];
#endif
};
/* Init function will return -1 in case of error, 0 if key is exactly
128, 192 or 256 bits or 1 if key length is multiple of 8 and in range
from 8 to 256 bits */
int twofish_init(struct twofish_ctx *ctx, const uint8_t key[], size_t keylen);
/* For all the following functions len must be multiple of 16.
* Encryption and decryption can be performed "in place" if
* src is equal to dst.
*/
/* electronic codebook */
void twofish_encrypt_buffer_ecb(const struct twofish_ctx *ctx, uint8_t *dst, const uint8_t *src, size_t len);
void twofish_decrypt_buffer_ecb(const struct twofish_ctx *ctx, uint8_t *dst, const uint8_t *src, size_t len);
/* cipher-block chaining */
void twofish_encrypt_buffer_cbc(const struct twofish_ctx *ctx, uint8_t *dst, const uint8_t *src, size_t len, uint64_t iv[2]);
void twofish_decrypt_buffer_cbc(const struct twofish_ctx *ctx, uint8_t *dst, const uint8_t *src, size_t len, uint64_t iv[2]);
#endif