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

   1 /* -*-c-*-
   2  *
   3  * The Twofish block cipher
   4  *
   5  * (c) 2000 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Notes on the Twofish block cipher ---------------------------------*
  29  *
  30  * Twofish was designed by Bruce Schneier, John Kelsey, Doug Whiting, David
  31  * Wagner, Chris Hall and Niels Ferguson.  The algorithm is unpatented and
  32  * free for anyone to use.  It was one of the five AES finalist algorithms.
  33  *
  34  * Twofish is a complex cipher offering various space and time tradeoffs.
  35  * This implementation has a heavy key schedule and fast bulk encryption.
  36  */
  37
  38 #ifndef CATACOMB_TWOFISH_H
  39 #define CATACOMB_TWOFISH_H
  40
  41 #ifdef __cplusplus
  42   extern "C" {
  43 #endif
  44
  45 /*----- Header files ------------------------------------------------------*/
  46
  47 #include <stddef.h>
  48
  49 #include <mLib/bits.h>
  50
  51 /*----- Magical numbers ---------------------------------------------------*/
  52
  53 #define TWOFISH_BLKSZ 16
  54 #define TWOFISH_KEYSZ 32
  55 #define TWOFISH_CLASS (N, L, 128)
  56
  57 extern const octet twofish_keysz[];
  58
  59 /*----- Data structures ---------------------------------------------------*/
  60
  61 typedef struct twofish_ctx {
  62   uint32 k[40];
  63   uint32 g[4][256];
  64 } twofish_ctx;
  65
  66 typedef struct twofish_fk {
  67   uint32 t0[8], t23[8], t4[2];
  68   octet t1[32];
  69 } twofish_fk;
  70
  71 /*----- Functions provided ------------------------------------------------*/
  72
  73 /* --- @twofish_initfk@ --- *
  74  *
  75  * Arguments:   @twofish_ctx *k@ = pointer to key block to fill in
  76  *              @const void *buf@ = pointer to buffer of key material
  77  *              @size_t sz@ = size of key material
  78  *              @const twofish_fk *fk@ = family-key information
  79  *
  80  * Returns:     ---
  81  *
  82  * Use:         Does the underlying Twofish key initialization with family
  83  *              key.  Pass in a family-key structure initialized to
  84  *              all-bits-zero for a standard key schedule.
  85  */
  86
  87 extern void twofish_initfk(twofish_ctx */*k*/, const void */*buf*/,
  88                            size_t /*sz*/, const twofish_fk */*fk*/);
  89
  90 /* --- @twofish_init@ --- *
  91  *
  92  * Arguments:   @twofish_ctx *k@ = pointer to key block to fill in
  93  *              @const void *buf@ = pointer to buffer of key material
  94  *              @size_t sz@ = size of key material
  95  *
  96  * Returns:     ---
  97  *
  98  * Use:         Initializes a Twofish key buffer.  Twofish accepts keys of up
  99  *              to 256 bits in length.
 100  */
 101
 102 extern void twofish_init(twofish_ctx */*k*/,
 103                          const void */*buf*/, size_t /*sz*/);
 104
 105 /* --- @twofish_fkinit@ --- *
 106  *
 107  * Arguments:   @twofish_fk *fk@ = pointer to family key block
 108  *              @const void *buf@ = pointer to buffer of key material
 109  *              @size_t sz@ = size of key material
 110  *
 111  * Returns:     ---
 112  *
 113  * Use:         Initializes a family-key buffer.  This implementation allows
 114  *              family keys of any size acceptable to the Twofish algorithm.
 115  */
 116
 117 extern void twofish_fkinit(twofish_fk */*fk*/,
 118                            const void */*buf*/, size_t /*sz*/);
 119
 120 /* --- @twofish_eblk@, @twofish_dblk@ --- *
 121  *
 122  * Arguments:   @const twofish_ctx *k@ = pointer to key block
 123  *              @const uint32 s[4]@ = pointer to source block
 124  *              @uint32 d[4]@ = pointer to destination block
 125  *
 126  * Returns:     ---
 127  *
 128  * Use:         Low-level block encryption and decryption.
 129  */
 130
 131 extern void twofish_eblk(const twofish_ctx */*k*/,
 132                          const uint32 */*s*/, uint32 */*d*/);
 133
 134 extern void twofish_dblk(const twofish_ctx */*k*/,
 135                          const uint32 */*s*/, uint32 */*d*/);
 136
 137 /*----- That's all, folks -------------------------------------------------*/
 138
 139 #ifdef __cplusplus
 140   }
 141 #endif
 142
 143 #endif