git.distorted.org.uk Git - u/mdw/catacomb/blob - rijndael.c

   1 /* -*-c-*-
   2  *
   3  * $Id: rijndael.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * The Rijndael 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 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <assert.h>
  33 #include <stdio.h>
  34
  35 #include <mLib/bits.h>
  36
  37 #include "blkc.h"
  38 #include "gcipher.h"
  39 #include "rijndael.h"
  40 #include "rijndael-base.h"
  41
  42 /*----- Main code ---------------------------------------------------------*/
  43
  44 /* --- @rijndael_init@ --- *
  45  *
  46  * Arguments:   @rijndael_ctx *k@ = pointer to context to initialize
  47  *              @const void *buf@ = pointer to buffer of key material
  48  *              @size_t sz@ = size of the key material
  49  *
  50  * Returns:     ---
  51  *
  52  * Use:         Initializes a Rijndael context with a particular key.  This
  53  *              implementation of Rijndael doesn't impose any particular
  54  *              limits on the key size except that it must be multiple of 4
  55  *              bytes long.  256 bits seems sensible, though.
  56  */
  57
  58 void rijndael_init(rijndael_ctx *k, const void *buf, size_t sz)
  59 {
  60   rijndael_setup(k, RIJNDAEL_BLKSZ / 4, buf, sz);
  61 }
  62
  63 /* --- @rijndael_eblk@, @rijndael_dblk@ --- *
  64  *
  65  * Arguments:   @const rijndael_ctx *k@ = pointer to Rijndael context
  66  *              @const uint32 s[4]@ = pointer to source block
  67  *              @uint32 d[4]@ = pointer to destination block
  68  *
  69  * Returns:     ---
  70  *
  71  * Use:         Low-level block encryption and decryption.
  72  */
  73
  74 #define DO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {                 \
  75   aa = what(t, a, b, c, d) ^ *w++;                                      \
  76   bb = what(t, b, c, d, a) ^ *w++;                                      \
  77   cc = what(t, c, d, a, b) ^ *w++;                                      \
  78   dd = what(t, d, a, b, c) ^ *w++;                                      \
  79 } while (0)
  80
  81 #define UNDO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {               \
  82   aa = what(t, a, d, c, b) ^ *w++;                                      \
  83   bb = what(t, b, a, d, c) ^ *w++;                                      \
  84   cc = what(t, c, b, a, d) ^ *w++;                                      \
  85   dd = what(t, d, c, b, a) ^ *w++;                                      \
  86 } while (0)
  87
  88 void rijndael_eblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
  89 {
  90   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
  91   uint32 aa, bb, cc, dd;
  92   const uint32 *w = k->w;
  93
  94   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
  95   aa = a; bb = b; cc = c; dd = d;
  96
  97   switch (k->nr) {
  98     case 14:
  99       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 100     case 13:
 101       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 102     case 12:
 103       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 104     case 11:
 105       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 106     case 10:
 107     default:
 108       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 109       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 110       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 111       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 112       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 113       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 114       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 115       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 116       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 117   }
 118   DO(SUB, S, a, b, c, d, aa, bb, cc, dd, w);
 119
 120   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 121 }
 122
 123 void rijndael_dblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
 124 {
 125   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
 126   uint32 aa, bb, cc, dd;
 127   const uint32 *w = k->wi;
 128
 129   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
 130   aa = a; bb = b; cc = c; dd = d;
 131
 132   switch (k->nr) {
 133     case 14:
 134       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 135     case 13:
 136       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 137     case 12:
 138       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 139     case 11:
 140       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 141     case 10:
 142     default:
 143       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 144       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 145       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 146       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 147       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 148       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 149       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 150       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 151       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 152   }
 153   UNDO(SUB, SI, a, b, c, d, aa, bb, cc, dd, w);
 154
 155   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 156 }
 157
 158 BLKC_TEST(RIJNDAEL, rijndael)
 159
 160 /*----- That's all, folks -------------------------------------------------*/