des-compat.c

/* des-compat.h
 *
 * The des block cipher, libdes/openssl-style interface.
 */

/* 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., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02111-1301, USA.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <string.h>
#include <assert.h>

#include "des-compat.h"

#include "cbc.h"
#include "macros.h"
#include "memxor.h"

struct des_compat_des3 { const struct des_ctx *keys[3]; }; 

static void
des_compat_des3_encrypt(struct des_compat_des3 *ctx,
			uint32_t length, uint8_t *dst, const uint8_t *src)
{
  nettle_des_encrypt(ctx->keys[0], length, dst, src);
  nettle_des_decrypt(ctx->keys[1], length, dst, dst);
  nettle_des_encrypt(ctx->keys[2], length, dst, dst);
}

static void
des_compat_des3_decrypt(struct des_compat_des3 *ctx,
			uint32_t length, uint8_t *dst, const uint8_t *src)
{
  nettle_des_decrypt(ctx->keys[2], length, dst, src);
  nettle_des_encrypt(ctx->keys[1], length, dst, dst);
  nettle_des_decrypt(ctx->keys[0], length, dst, dst);
}

void
des_ecb3_encrypt(const_des_cblock *src, des_cblock *dst,
		 des_key_schedule k1,
		 des_key_schedule k2,
		 des_key_schedule k3, int enc)
{
  struct des_compat_des3 keys;
  keys.keys[0] = k1;
  keys.keys[1] = k2;
  keys.keys[2] = k3;

  ((enc == DES_ENCRYPT) ? des_compat_des3_encrypt : des_compat_des3_decrypt)