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   1 /* -*-c-*-
   2  *
   3  * $Id: safer.h,v 1.2 2001/04/29 18:11:38 mdw Exp $
   4  *
   5  * The SAFER block cipher
   6  *
   7  * (c) 2001 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: safer.h,v $
  33  * Revision 1.2  2001/04/29 18:11:38  mdw
  34  * Add some notes.
  35  *
  36  * Revision 1.1  2001/04/29 17:37:35  mdw
  37  * Added SAFER block cipher.
  38  *
  39  */
  40
  41 /*----- Notes on the SAFER block cipher -----------------------------------*
  42  *
  43  * SAFER was designed by James Massey (who also worked on IDEA) for Cylink.
  44  * It's free -- patents or other silliness.  The original key schedule had
  45  * some weaknesses, and a new one (the SK version) was added.  SAFER has a
  46  * variable number of rounds.  The standard interface uses the recommended
  47  * number for the given key schedule algorithm and key size.
  48  *
  49  * SAFER got a bad press in Schneier's book `Applied Cryptography'.  I think
  50  * this is undeserved.  SAFER is a well-designed cipher which mostly looks
  51  * pretty solid.
  52  */
  53
  54 #ifndef CATACOMB_SAFER_H
  55 #define CATACOMB_SAFER_H
  56
  57 #ifdef __cplusplus
  58   extern "C" {
  59 #endif
  60
  61 /*----- Header files ------------------------------------------------------*/
  62
  63 #include <stddef.h>
  64
  65 #include <mLib/bits.h>
  66
  67 /*----- Magical numbers ---------------------------------------------------*/
  68
  69 #define SAFER_BLKSZ 8
  70 #define SAFER_KEYSZ 8
  71 #define SAFER_CLASS (N, B, 64)
  72
  73 #define SAFERSK_BLKSZ SAFER_BLKSZ
  74 #define SAFERSK_KEYSZ 16
  75 #define SAFERSK_CLASS SAFER_CLASS
  76
  77 #define SAFER_MAXROUNDS 12
  78
  79 extern const octet safer_keysz[];
  80 #define safersk_keysz safer_keysz
  81
  82 /*----- Data structures ---------------------------------------------------*/
  83
  84 typedef struct safer_ctx {
  85   octet k[8 * (2 * SAFER_MAXROUNDS + 1)];
  86   unsigned r;
  87 } safer_ctx, safersk_ctx;
  88
  89 /*----- Functions provided ------------------------------------------------*/
  90
  91 /* --- @safer_setup@ --- *
  92  *
  93  * Arguments:   @safer_ctx *k@ = pointer to context to initialize
  94  *              @unsigned r@ = number of rounds wanted
  95  *              @unsigned f@ = various other flags
  96  *              @const void *buf@ = pointer to key material
  97  *              @size_t sz@ = size of key material in bytes
  98  *
  99  * Returns:     ---
 100  *
 101  * Use:         Initializes an SAFER expanded key.  A default number of
 102  *              rounds is chosen, based on the key length.
 103  */
 104
 105 #define SAFER_SK 1u
 106
 107 extern void safer_setup(safer_ctx */*k*/, unsigned /*r*/, unsigned /*f*/,
 108                         const void */*buf*/, size_t /*sz*/);
 109
 110 /* --- @safer_init@, @safersk_init@ --- *
 111  *
 112  * Arguments:   @safer_ctx *k@ = pointer to context to initialize
 113  *              @const void *buf@ = pointer to key material
 114  *              @size_t sz@ = size of key material in bytes
 115  *
 116  * Returns:     ---
 117  *
 118  * Use:         Initializes an SAFER expanded key.  A default number of
 119  *              rounds is chosen, based on the key length.
 120  */
 121
 122 extern void safer_init(safer_ctx */*k*/,
 123                        const void */*buf*/, size_t /*sz*/);
 124 extern void safersk_init(safer_ctx */*k*/,
 125                          const void */*buf*/, size_t /*sz*/);
 126
 127 /* --- @safer_eblk@, @safer_dblk@ --- *
 128  *
 129  * Arguments:   @const safer_ctx *k@ = pointer to SAFER context
 130  *              @const uint32 s[2]@ = pointer to source block
 131  *              @const uint32 d[2]@ = pointer to destination block
 132  *
 133  * Returns:     ---
 134  *
 135  * Use:         Low-level block encryption and decryption.
 136  */
 137
 138 extern void safer_eblk(const safer_ctx */*k*/,
 139                        const uint32 */*s*/, uint32 */*dst*/);
 140 extern void safer_dblk(const safer_ctx */*k*/,
 141                        const uint32 */*s*/, uint32 */*dst*/);
 142
 143 #define safersk_eblk safer_eblk
 144 #define safersk_dblk safer_dblk
 145
 146 /*----- That's all, folks -------------------------------------------------*/
 147
 148 #ifdef __cplusplus
 149   }
 150 #endif
 151
 152 #endif