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

   1 /* -*-c-*-
   2  *
   3  * The Square 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 Square block cipher ----------------------------------*
  29  *
  30  * Invented by Joan Daemen and Vincent Rijmen, Square is a fast and
  31  * relatively simple 128-bit block cipher.  It is the predecessor to
  32  * Rijndael.  I have grave doubts about the security of Square, though: a
  33  * dedicated attack against Square's structure by Knudsen has been extended
  34  * by the Twofish team against Rijndael, and I believe that this extended
  35  * attack is also effective against Square.  This is a shame: the structure
  36  * of Square (and Rijndael) is extremely elegant, and has some extremely nice
  37  * properties.
  38  */
  39
  40 #ifndef CATACOMB_SQUARE_H
  41 #define CATACOMB_SQUARE_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 SQUARE_BLKSZ 16
  56 #define SQUARE_KEYSZ 16
  57 #define SQUARE_CLASS (N, L, 128)
  58
  59 extern const octet square_keysz[];
  60
  61 /*----- Data structures ---------------------------------------------------*/
  62
  63 #define SQUARE_MAXROUNDS 8
  64 #define SQUARE_KWORDS ((SQUARE_MAXROUNDS + 1) * (SQUARE_BLKSZ / 4))
  65
  66 typedef struct square_ctx {
  67   uint32 w[SQUARE_KWORDS];
  68   uint32 wi[SQUARE_KWORDS];
  69 } square_ctx;
  70
  71 /*----- Functions provided ------------------------------------------------*/
  72
  73 /* --- @square_init@ --- *
  74  *
  75  * Arguments:   @square_ctx *k@ = pointer to context to initialize
  76  *              @const void *buf@ = pointer to buffer of key material
  77  *              @size_t sz@ = size of the key material
  78  *
  79  * Returns:     ---
  80  *
  81  * Use:         Initializes a Square context with a particular key.  This
  82  *              implementation of Square doesn't impose any particular
  83  *              limits on the key size except that it must be multiple of 4
  84  *              bytes long.  256 bits seems sensible, though.
  85  */
  86
  87 extern void square_init(square_ctx */*k*/,
  88                           const void */*buf*/, size_t /*sz*/);
  89
  90 /* --- @square_eblk@, @square_dblk@ --- *
  91  *
  92  * Arguments:   @const square_ctx *k@ = pointer to Square context
  93  *              @const uint32 s[4]@ = pointer to source block
  94  *              @uint32 d[4]@ = pointer to destination block
  95  *
  96  * Returns:     ---
  97  *
  98  * Use:         Low-level block encryption and decryption.
  99  */
 100
 101 extern void square_eblk(const square_ctx */*k*/,
 102                           const uint32 */*s*/, uint32 */*dst*/);
 103 extern void square_dblk(const square_ctx */*k*/,
 104                           const uint32 */*s*/, uint32 */*dst*/);
 105
 106 /*----- That's all, folks -------------------------------------------------*/
 107
 108 #ifdef __cplusplus
 109   }
 110 #endif
 111
 112 #endif