3 * Triple DES cipher. Three key encrypt-decrypt-encrypt.
6 /* nettle, low-level cryptographics library
8 * Copyright (C) 2001 Niels Möller
10 * The nettle library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published by
12 * the Free Software Foundation; either version 2.1 of the License, or (at your
13 * option) any later version.
15 * The nettle library is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
18 * License for more details.
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with the nettle library; see the file COPYING.LIB. If not, write to
22 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
32 /* It's possible to make some more general pipe construction, like the
33 * lsh/src/cascade.c, but as in practice it's never used for anything
34 * like triple DES, it's not worth the effort. */
36 /* Returns 1 for good keys and 0 for weak keys. */
38 des3_set_key(struct des3_ctx *ctx, const uint8_t *key)
43 for (i = 0; i<3; i++, key += DES_KEY_SIZE)
44 if (!des_set_key(&ctx->des[i], key))
51 des3_encrypt(const struct des3_ctx *ctx,
52 unsigned length, uint8_t *dst,
55 des_encrypt(&ctx->des[0],
57 des_decrypt(&ctx->des[1],
59 des_encrypt(&ctx->des[2],
64 des3_decrypt(const struct des3_ctx *ctx,
65 unsigned length, uint8_t *dst,
68 des_decrypt(&ctx->des[2],
70 des_encrypt(&ctx->des[1],
72 des_decrypt(&ctx->des[0],