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/* serpent.h
*
* The serpent block cipher.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2001 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
/* Serpent is a 128-bit block cipher that accepts a key size of 256
* bits, designed by Ross Anderson, Eli Biham, and Lars Knudsen. See
* http://www.cl.cam.ac.uk/~rja14/serpent.html for details.
*/
#ifndef NETTLE_SERPENT_H_INCLUDED
#define NETTLE_SERPENT_H_INCLUDED
#include <inttypes.h>
#define SERPENT_BLOCK_SIZE 16
/* Other key lengths are possible, but the design of Serpent makes
* smaller key lengths quite pointless; they cheated with the AES
* requirements, using a 256-bit key length exclusively and just
* padding it out if the desired key length was less, so there really
* is no advantage to using key lengths less than 256 bits. */
#define SERPENT_KEY_SIZE 32
/* Allow keys of size 128 <= bits <= 256 */
#define SERPENT_MIN_KEY_SIZE 16
#define SERPENT_MAX_KEY_SIZE 32
struct serpent_ctx
{
uint32_t keys[33][4]; /* key schedule */
};
void
serpent_set_key(struct serpent_ctx *ctx,
unsigned length, const uint8_t *key);
void
serpent_encrypt(struct serpent_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *src);
void
serpent_decrypt(struct serpent_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *src);
#endif /* NETTLE_SERPENT_H_INCLUDED */
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