git.distorted.org.uk Git - u/mdw/catacomb/blob - serpent.h

   1 /* -*-c-*-
   2  *
   3  * $Id: serpent.h,v 1.3 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * The Serpent block cipher
   6  *
   7  * (c) 2000 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Notes on the Serpent block cipher ---------------------------------*
  31  *
  32  * Serpent was designed and proposed for the AES contest by Ross Anderson,
  33  * Eli Biham and Lars Knudsen.  It's not particularly quick, but is
  34  * stunningly secure.  The best differential and linear attacks are
  35  * speculated to require %$2^{256}$% texts (it's a 128-bit block cipher).
  36  * The designers originally intended to file a patent, but failed to persue
  37  * it.  Use of the algorithm is completely unencumbered.
  38  */
  39
  40 #ifndef CATACOMB_SERPENT_H
  41 #define CATACOMB_SERPENT_H
  42
  43 #ifdef __cplusplus
  44   extern "C" {
  45 #endif
  46
  47 /*----- Header files ------------------------------------------------------*/
  48
  49 #include <stddef.h>
  50
  51 #include <mLib/bits.h>
  52
  53 /*----- Magic numbers -----------------------------------------------------*/
  54
  55 #define SERPENT_BLKSZ 16
  56 #define SERPENT_KEYSZ 32
  57 #define SERPENT_CLASS (N, L, 128)
  58
  59 extern const octet serpent_keysz[];
  60
  61 /*----- Data structures ---------------------------------------------------*/
  62
  63 typedef struct serpent_ctx {
  64   uint32 k[4 * 33];
  65 } serpent_ctx;
  66
  67 /*----- Functions provided ------------------------------------------------*/
  68
  69 /* --- @serpent_init@ --- *
  70  *
  71  * Arguments:   @serpent_ctx *k@ = pointer to context block to initialize
  72  *              @const void *buf@ = pointer to input buffer
  73  *              @size_t sz@ = size of input buffer
  74  *
  75  * Returns:     ---
  76  *
  77  * Use:         Initializes a Serpent context.  The key may be any length of
  78  *              up to 32 bytes (256 bits).
  79  */
  80
  81 extern void serpent_init(serpent_ctx */*k*/,
  82                          const void */*buf*/, size_t /*sz*/);
  83
  84 /* --- @serpent_eblk@, @serpent_dblk@ --- *
  85  *
  86  * Arguments:   @const serpent_ctx *k@ = pointer to key context
  87  *              @const uint32 s[4]@ = pointer to source block
  88  *              @uint32 d[4]@ = pointer to destination block
  89  *
  90  * Returns:     ---
  91  *
  92  * Use:         Low-level block encryption.
  93  */
  94
  95 extern void serpent_eblk(const serpent_ctx */*k*/,
  96                          const uint32 */*s*/, uint32 */*d*/);
  97 extern void serpent_dblk(const serpent_ctx */*k*/,
  98                          const uint32 */*s*/, uint32 */*d*/);
  99
 100 /*----- That's all, folks -------------------------------------------------*/
 101
 102 #ifdef __cplusplus
 103   }
 104 #endif
 105
 106 #endif