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   1 /* -*-c-*-
   2  *
   3  * $Id: twofish.h,v 1.4 2002/01/13 13:37:59 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: twofish.h,v $
  33  * Revision 1.4  2002/01/13 13:37:59  mdw
  34  * Add support for Twofish family keys.
  35  *
  36  * Revision 1.3  2001/04/29 18:12:43  mdw
  37  * Fix formatting.
  38  *
  39  * Revision 1.2  2000/10/08 15:48:58  mdw
  40  * Update comments now that AES has been chosen.
  41  *
  42  * Revision 1.1  2000/06/17 12:10:17  mdw
  43  * New cipher.
  44  *
  45  */
  46
  47 /*----- Notes on the Twofish block cipher ---------------------------------*
  48  *
  49  * Twofish was designed by Bruce Schneier, John Kelsey, Doug Whiting, David
  50  * Wagner, Chris Hall and Niels Ferguson.  The algorithm is unpatented and
  51  * free for anyone to use.  It was one of the five AES finalist algorithms.
  52  *
  53  * Twofish is a complex cipher offering various space and time tradeoffs.
  54  * This implementation has a heavy key schedule and fast bulk encryption.
  55  */
  56
  57 #ifndef CATACOMB_TWOFISH_H
  58 #define CATACOMB_TWOFISH_H
  59
  60 #ifdef __cplusplus
  61   extern "C" {
  62 #endif
  63
  64 /*----- Header files ------------------------------------------------------*/
  65
  66 #include <stddef.h>
  67
  68 #include <mLib/bits.h>
  69
  70 /*----- Magical numbers ---------------------------------------------------*/
  71
  72 #define TWOFISH_BLKSZ 16
  73 #define TWOFISH_KEYSZ 32
  74 #define TWOFISH_CLASS (N, L, 128)
  75
  76 extern const octet twofish_keysz[];
  77
  78 /*----- Data structures ---------------------------------------------------*/
  79
  80 typedef struct twofish_ctx {
  81   uint32 k[40];
  82   uint32 g[4][256];
  83 } twofish_ctx;
  84
  85 typedef struct twofish_fk {
  86   uint32 t0[8], t23[8], t4[2];
  87   octet t1[32];
  88 } twofish_fk;
  89
  90 /*----- Functions provided ------------------------------------------------*/
  91
  92 /* --- @twofish_initfk@ --- *
  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  *              @const twofish_fk *fk@ = family-key information
  98  *
  99  * Returns:     ---
 100  *
 101  * Use:         Does the underlying Twofish key initialization with family
 102  *              key.  Pass in a family-key structure initialized to
 103  *              all-bits-zero for a standard key schedule.
 104  */
 105
 106 extern void twofish_initfk(twofish_ctx */*k*/, const void */*buf*/,
 107                            size_t /*sz*/, const twofish_fk */*fk*/);
 108
 109 /* --- @twofish_init@ --- *
 110  *
 111  * Arguments:   @twofish_ctx *k@ = pointer to key block to fill in
 112  *              @const void *buf@ = pointer to buffer of key material
 113  *              @size_t sz@ = size of key material
 114  *
 115  * Returns:     ---
 116  *
 117  * Use:         Initializes a Twofish key buffer.  Twofish accepts keys of up
 118  *              to 256 bits in length.
 119  */
 120
 121 extern void twofish_init(twofish_ctx */*k*/,
 122                          const void */*buf*/, size_t /*sz*/);
 123
 124 /* --- @twofish_fkinit@ --- *
 125  *
 126  * Arguments:   @twofish_fk *fk@ = pointer to family key block
 127  *              @const void *buf@ = pointer to buffer of key material
 128  *              @size_t sz@ = size of key material
 129  *
 130  * Returns:     ---
 131  *
 132  * Use:         Initializes a family-key buffer.  This implementation allows
 133  *              family keys of any size acceptable to the Twofish algorithm.
 134  */
 135
 136 extern void twofish_fkinit(twofish_fk */*fk*/,
 137                            const void */*buf*/, size_t /*sz*/);
 138
 139 /* --- @twofish_eblk@, @twofish_dblk@ --- *
 140  *
 141  * Arguments:   @const twofish_ctx *k@ = pointer to key block
 142  *              @const uint32 s[4]@ = pointer to source block
 143  *              @uint32 d[4]@ = pointer to destination block
 144  *
 145  * Returns:     ---
 146  *
 147  * Use:         Low-level block encryption and decryption.
 148  */
 149
 150 extern void twofish_eblk(const twofish_ctx */*k*/,
 151                          const uint32 */*s*/, uint32 */*d*/);
 152
 153 extern void twofish_dblk(const twofish_ctx */*k*/,
 154                          const uint32 */*s*/, uint32 */*d*/);
 155
 156 /*----- That's all, folks -------------------------------------------------*/
 157
 158 #ifdef __cplusplus
 159   }
 160 #endif
 161
 162 #endif