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,
  76              (const rijndael_ctx *k, const uint32 s[4], uint32 d[4]),
  77              (k, s, d), pick_eblk, simple_eblk)
  78
  79 CPU_DISPATCH(EMPTY, EMPTY, void, rijndael_dblk,
  80              (const rijndael_ctx *k, const uint32 s[4], uint32 d[4]),
  81              (k, s, d), pick_dblk, simple_dblk)
  82
  83 #if CPUFAM_X86 || CPUFAM_AMD64
  84 extern rijndael_eblk__functype rijndael_eblk_x86ish_aesni;
  85 extern rijndael_dblk__functype rijndael_dblk_x86ish_aesni;
  86 #endif
  87
  88 static rijndael_eblk__functype *pick_eblk(void)
  89 {
  90 #if CPUFAM_X86 || CPUFAM_AMD64
  91   DISPATCH_PICK_COND(rijndael_eblk, rijndael_eblk_x86ish_aesni,
  92                      cpu_feature_p(CPUFEAT_X86_AESNI));
  93 #endif
  94   DISPATCH_PICK_FALLBACK(rijndael_eblk, simple_eblk);
  95 }
  96
  97 static rijndael_dblk__functype *pick_dblk(void)
  98 {
  99 #if CPUFAM_X86 || CPUFAM_AMD64
 100   DISPATCH_PICK_COND(rijndael_dblk, rijndael_dblk_x86ish_aesni,
 101                      cpu_feature_p(CPUFEAT_X86_AESNI));
 102 #endif
 103   DISPATCH_PICK_FALLBACK(rijndael_dblk, simple_dblk);
 104 }
 105
 106 #define DO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {                 \
 107   aa = what(t, a, b, c, d) ^ *w++;                                      \
 108   bb = what(t, b, c, d, a) ^ *w++;                                      \
 109   cc = what(t, c, d, a, b) ^ *w++;                                      \
 110   dd = what(t, d, a, b, c) ^ *w++;                                      \
 111 } while (0)
 112
 113 #define UNDO(what, t, aa, bb, cc, dd, a, b, c, d, w) do {               \
 114   aa = what(t, a, d, c, b) ^ *w++;                                      \
 115   bb = what(t, b, a, d, c) ^ *w++;                                      \
 116   cc = what(t, c, b, a, d) ^ *w++;                                      \
 117   dd = what(t, d, c, b, a) ^ *w++;                                      \
 118 } while (0)
 119
 120 static void simple_eblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
 121 {
 122   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
 123   uint32 aa, bb, cc, dd;
 124   const uint32 *w = k->w;
 125
 126   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
 127   aa = a; bb = b; cc = c; dd = d;
 128
 129   switch (k->nr) {
 130     case 14:
 131       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 132     case 13:
 133       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 134     case 12:
 135       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 136     case 11:
 137       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 138     case 10:
 139     default:
 140       DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w);
 141       DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w);
 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   }
 150   DO(SUB, S, a, b, c, d, aa, bb, cc, dd, w);
 151
 152   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 153 }
 154
 155 static void simple_dblk(const rijndael_ctx *k, const uint32 *s, uint32 *dst)
 156 {
 157   uint32 a = s[0], b = s[1], c = s[2], d = s[3];
 158   uint32 aa, bb, cc, dd;
 159   const uint32 *w = k->wi;
 160
 161   a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++;
 162   aa = a; bb = b; cc = c; dd = d;
 163
 164   switch (k->nr) {
 165     case 14:
 166       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 167     case 13:
 168       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 169     case 12:
 170       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 171     case 11:
 172       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 173     case 10:
 174     default:
 175       UNDO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w);
 176       UNDO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w);
 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   }
 185   UNDO(SUB, SI, a, b, c, d, aa, bb, cc, dd, w);
 186
 187   dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
 188 }
 189
 190 BLKC_TEST(RIJNDAEL, rijndael)
 191
 192 /*----- That's all, folks -------------------------------------------------*/