release/src/router/nettle/serpent.h

   1 /* serpent.h
   2  *
   3  * The serpent block cipher.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2001 Niels Möller
   9  *
  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.
  14  *
  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.
  19  *
  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., 51 Franklin Street, Fifth Floor, Boston,
  23  * MA 02111-1301, USA.
  24  */
  25
  26 /* Serpent is a 128-bit block cipher that accepts a key size of 256
  27  * bits, designed by Ross Anderson, Eli Biham, and Lars Knudsen. See
  28  * http://www.cl.cam.ac.uk/~rja14/serpent.html for details.
  29  */
  30
  31 #ifndef NETTLE_SERPENT_H_INCLUDED
  32 #define NETTLE_SERPENT_H_INCLUDED
  33
  34 #include "nettle-types.h"
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /* Name mangling */
  41 #define serpent_set_key nettle_serpent_set_key
  42 #define serpent_encrypt nettle_serpent_encrypt
  43 #define serpent_decrypt nettle_serpent_decrypt
  44
  45 #define SERPENT_BLOCK_SIZE 16
  46
  47 /* Other key lengths are possible, but the design of Serpent makes
  48  * smaller key lengths quite pointless; they cheated with the AES
  49  * requirements, using a 256-bit key length exclusively and just
  50  * padding it out if the desired key length was less, so there really
  51  * is no advantage to using key lengths less than 256 bits. */
  52 #define SERPENT_KEY_SIZE 32
  53
  54 /* Allow keys of size 128 <= bits <= 256 */
  55
  56 #define SERPENT_MIN_KEY_SIZE 16
  57 #define SERPENT_MAX_KEY_SIZE 32
  58
  59 struct serpent_ctx
  60 {
  61   uint32_t keys[33][4];  /* key schedule */
  62 };
  63
  64 void
  65 serpent_set_key(struct serpent_ctx *ctx,
  66                 unsigned length, const uint8_t *key);
  67
  68 void
  69 serpent_encrypt(const struct serpent_ctx *ctx,
  70                 unsigned length, uint8_t *dst,
  71                 const uint8_t *src);
  72 void
  73 serpent_decrypt(const struct serpent_ctx *ctx,
  74                 unsigned length, uint8_t *dst,
  75                 const uint8_t *src);
  76
  77 #ifdef __cplusplus
  78 }
  79 #endif
  80
  81 #endif /* NETTLE_SERPENT_H_INCLUDED */