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

   1 /* -*-c-*-
   2  *
   3  * The Rijndael 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 /*----- Header files ------------------------------------------------------*/
  29
  30 #include "config.h"
  31
  32 #include <assert.h>
  33 #include <stdio.h>
  34
  35 #include <mLib/bits.h>
  36
  37 #include "blkc.h"
  38 #include "dispatch.h"
  39 #include "gcipher.h"
  40 #include "rijndael.h"
  41 #include "rijndael-base.h"
  42
  43 /*----- Main code ---------------------------------------------------------*/
  44
  45 /* --- @rijndael_init@ --- *
  46  *
  47  * Arguments:   @rijndael_ctx *k@ = pointer to context to initialize
  48  *              @const void *buf@ = pointer to buffer of key material
  49  *              @size_t sz@ = size of the key material
  50  *
  51  * Returns:     ---
  52  *
  53  * Use:         Initializes a Rijndael context with a particular key.  This
  54  *              implementation of Rijndael doesn't impose any particular
  55  *              limits on the key size except that it must be multiple of 4
  56  *              bytes long.  256 bits seems sensible, though.
  57  */
  58
  59 void rijndael_init(rijndael_ctx *k, const void *buf, size_t sz)
  60 {
  61   rijndael_setup(k, RIJNDAEL_BLKSZ / 4, buf, sz);
  62 }
  63
  64 /* --- @rijndael_eblk@, @rijndael_dblk@ --- *
  65  *
  66  * Arguments:   @const rijndael_ctx *k@ = pointer to Rijndael context
  67  *              @const uint32 s[4]@ = pointer to source block
  68  *              @uint32 d[4]@ = pointer to destination block
  69  *
  70  * Returns:     ---
  71  *
  72  * Use:         Low-level block encryption and decryption.
  73  */
  74
  75 CPU_DISPATCH(EMPTY, EMPTY, void, rijndael_eblk, (const rijndael_ctx *k,
  76                                                  const uint32 s[4],
  77                                                  uint32 d[4]),
  78              (k, s, d), pick_eblk, simple_eblk)
  79
  80 CPU_DISPATCH(EMPTY, EMPTY, void, rijndael_dblk, (const rijndael_ctx *k,
  81                                                  const uint32 s[4],
  82                                                  uint32 d[4]),
  83              (k, s, d), pick_dblk, simple_dblk)
  84
  85 #if CPUFAM_X86 || CPUFAM_AMD64
  86 extern rijndael_eblk__functype rijndael_eblk_x86ish_aesni;
  87 extern rijndael_dblk__functype rijndael_dblk_x86ish_aesni;
  88 #endif
  89
  90 static rijndael_eblk__functype *pick_eblk(void)
  91 {
  92 #if CPUFAM_X86 || CPUFAM_AMD64
  93   DISPATCH_PICK_COND(rijndael_eblk, rijndael_eblk_x86ish_aesni,
  94                      cpu_feature_p(CPUFEAT_X86_AESNI));
  95 #endif
  96   DISPATCH_PICK_FALLBACK(rijndael_eblk, simple_eblk);
  97 }
  98
  99 static rijndael_dblk__functype *pick_dblk(void)
 100 {
 101 #if CPUFAM_X86 || CPUFAM_AMD64
 102   DISPATCH_PICK_COND(rijndael_dblk, rijndael_dblk_x86ish_aesni,
 103                      cpu_feature_p(CPUFEAT_X86_AESNI));
 104 #endif
 105   DISPATCH_PICK_FALLBACK(rijndael_dblk, simple_dblk);
 106 }
 107
 108 #define DO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {                 \
 109   aa = what(t, a, b, c, d) ^ *w++;                                      \
 110   bb = what(t, b, c, d, a) ^ *w++;                                      \
 111   cc = what(t, c, d, a, b) ^ *w++;                                      \
 112   dd = what(t, d, a, b, c) ^ *w++;                                      \
 113 } while (0)
 114
 115 #define UNDO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {               \
 116   aa = what(t, a, d, c, b) ^ *w++;                                      \
 117   bb = what(t, b, a, d, c) ^ *w++;                                      \
 118   cc = what(t, c, b, a, d) ^ *w++;                                      \
 119   dd = what(t, d, c, b, a) ^ *w++;                                      \
 120 } while (0)
 121
 122 static void simple_eblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
 123 {
 124   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
 125   uint32 aa, bb, cc, dd;
 126   const uint32 *w = k->w;
 127
 128   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
 129   aa = a; bb = b; cc = c; dd = d;
 130
 131   switch (k->nr) {
 132     case 14:
 133       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 134     case 13:
 135       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 136     case 12:
 137       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 138     case 11:
 139       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 140     case 10:
 141     default:
 142       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 143       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 144       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 145       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 146       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 147       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 148       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 149       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 150       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 151   }
 152   DO(SUB, S, a, b, c, d, aa, bb, cc, dd, w);
 153
 154   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 155 }
 156
 157 static void simple_dblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
 158 {
 159   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
 160   uint32 aa, bb, cc, dd;
 161   const uint32 *w = k->wi;
 162
 163   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
 164   aa = a; bb = b; cc = c; dd = d;
 165
 166   switch (k->nr) {
 167     case 14:
 168       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 169     case 13:
 170       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 171     case 12:
 172       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 173     case 11:
 174       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 175     case 10:
 176     default:
 177       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 178       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 179       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 180       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 181       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 182       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 183       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 184       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 185       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 186   }
 187   UNDO(SUB, SI, a, b, c, d, aa, bb, cc, dd, w);
 188
 189   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 190 }
 191
 192 BLKC_TEST(RIJNDAEL, rijndael)
 193
 194 /*----- That's all, folks -------------------------------------------------*/