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/*
* Twofish for CryptoAPI
*
* Originaly Twofish for GPG
* By Matthew Skala <mskala@ansuz.sooke.bc.ca>, July 26, 1998
* 256-bit key length added March 20, 1999
* Some modifications to reduce the text size by Werner Koch, April, 1998
* Ported to the kerneli patch by Marc Mutz <Marc@Mutz.com>
* Ported to CryptoAPI by Colin Slater <hoho@tacomeat.net>
*
* The original author has disclaimed all copyright interest in this
* code and thus put it in the public domain. The subsequent authors
* have put this under the GNU General Public License.
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* 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. 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* This code is a "clean room" implementation, written from the paper
* _Twofish: A 128-Bit Block Cipher_ by Bruce Schneier, John Kelsey,
* Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson, available
* through http://www.counterpane.com/twofish.html
*
* For background information on multiplication in finite fields, used for
* the matrix operations in the key schedule, see the book _Contemporary
* Abstract Algebra_ by Joseph A. Gallian, especially chapter 22 in the
* Third Edition.
*/
#ifndef _TWOFISH_
#define _TWOFISH_
#include "uint.h"
#define TF_MIN_KEY_SIZE 16
#define TF_MAX_KEY_SIZE 32
#define TF_BLOCK_SIZE 16
/* Structure for an expanded Twofish key. s contains the key-dependent
* S-boxes composed with the MDS matrix; w contains the eight "whitening"
* subkeys, K[0] through K[7]. k holds the remaining, "round" subkeys. Note
* that k[i] corresponds to what the Twofish paper calls K[i+8]. */
struct twofish_ctx {
u32 s[4][256], w[8], k[32];
};
/* Perform the key setup. return -1 if unsupported key length */
int twofish_setkey(void *cx, const u8 *key, u32 key_len, u32 *flags);
/* Encrypt one block. in and out may be the same. */
void twofish_encrypt(void *cx, u8 *out, const u8 *in);
/* Decrypt one block. in and out may be the same. */
void twofish_decrypt(void *cx, u8 *out, const u8 *in);
/* memcpy */
/*
void twofish_decrypt_fake(void *cx, u8 *out, const u8 *in);
void twofish_encrypt_fake(void *cx, u8 *out, const u8 *in);
*/
#endif
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