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   1 /* -*-c-*-
   2  *
   3  * $Id: twofish.h,v 1.5 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * The Twofish 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 Twofish block cipher ---------------------------------*
  31  *
  32  * Twofish was designed by Bruce Schneier, John Kelsey, Doug Whiting, David
  33  * Wagner, Chris Hall and Niels Ferguson.  The algorithm is unpatented and
  34  * free for anyone to use.  It was one of the five AES finalist algorithms.
  35  *
  36  * Twofish is a complex cipher offering various space and time tradeoffs.
  37  * This implementation has a heavy key schedule and fast bulk encryption.
  38  */
  39
  40 #ifndef CATACOMB_TWOFISH_H
  41 #define CATACOMB_TWOFISH_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 /*----- Magical numbers ---------------------------------------------------*/
  54
  55 #define TWOFISH_BLKSZ 16
  56 #define TWOFISH_KEYSZ 32
  57 #define TWOFISH_CLASS (N, L, 128)
  58
  59 extern const octet twofish_keysz[];
  60
  61 /*----- Data structures ---------------------------------------------------*/
  62
  63 typedef struct twofish_ctx {
  64   uint32 k[40];
  65   uint32 g[4][256];
  66 } twofish_ctx;
  67
  68 typedef struct twofish_fk {
  69   uint32 t0[8], t23[8], t4[2];
  70   octet t1[32];
  71 } twofish_fk;
  72
  73 /*----- Functions provided ------------------------------------------------*/
  74
  75 /* --- @twofish_initfk@ --- *
  76  *
  77  * Arguments:   @twofish_ctx *k@ = pointer to key block to fill in
  78  *              @const void *buf@ = pointer to buffer of key material
  79  *              @size_t sz@ = size of key material
  80  *              @const twofish_fk *fk@ = family-key information
  81  *
  82  * Returns:     ---
  83  *
  84  * Use:         Does the underlying Twofish key initialization with family
  85  *              key.  Pass in a family-key structure initialized to
  86  *              all-bits-zero for a standard key schedule.
  87  */
  88
  89 extern void twofish_initfk(twofish_ctx */*k*/, const void */*buf*/,
  90                            size_t /*sz*/, const twofish_fk */*fk*/);
  91
  92 /* --- @twofish_init@ --- *
  93  *
  94  * Arguments:   @twofish_ctx *k@ = pointer to key block to fill in
  95  *              @const void *buf@ = pointer to buffer of key material
  96  *              @size_t sz@ = size of key material
  97  *
  98  * Returns:     ---
  99  *
 100  * Use:         Initializes a Twofish key buffer.  Twofish accepts keys of up
 101  *              to 256 bits in length.
 102  */
 103
 104 extern void twofish_init(twofish_ctx */*k*/,
 105                          const void */*buf*/, size_t /*sz*/);
 106
 107 /* --- @twofish_fkinit@ --- *
 108  *
 109  * Arguments:   @twofish_fk *fk@ = pointer to family key block
 110  *              @const void *buf@ = pointer to buffer of key material
 111  *              @size_t sz@ = size of key material
 112  *
 113  * Returns:     ---
 114  *
 115  * Use:         Initializes a family-key buffer.  This implementation allows
 116  *              family keys of any size acceptable to the Twofish algorithm.
 117  */
 118
 119 extern void twofish_fkinit(twofish_fk */*fk*/,
 120                            const void */*buf*/, size_t /*sz*/);
 121
 122 /* --- @twofish_eblk@, @twofish_dblk@ --- *
 123  *
 124  * Arguments:   @const twofish_ctx *k@ = pointer to key block
 125  *              @const uint32 s[4]@ = pointer to source block
 126  *              @uint32 d[4]@ = pointer to destination block
 127  *
 128  * Returns:     ---
 129  *
 130  * Use:         Low-level block encryption and decryption.
 131  */
 132
 133 extern void twofish_eblk(const twofish_ctx */*k*/,
 134                          const uint32 */*s*/, uint32 */*d*/);
 135
 136 extern void twofish_dblk(const twofish_ctx */*k*/,
 137                          const uint32 */*s*/, uint32 */*d*/);
 138
 139 /*----- That's all, folks -------------------------------------------------*/
 140
 141 #ifdef __cplusplus
 142   }
 143 #endif
 144
 145 #endif