chiark - git - mdw - catacomb/blob - symm/des-base.h

   1 /* -*-c-*-
   2  *
   3  * Common features for DES implementation
   4  *
   5  * (c) 1999 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 #ifndef CATACOMB_DES_BASE_H
  29 #define CATACOMB_DES_BASE_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <mLib/bits.h>
  38
  39 /*----- External data -----------------------------------------------------*/
  40
  41 extern const uint32 des_sp[8][64];
  42
  43 /*----- Macros ------------------------------------------------------------*/
  44
  45 /* --- @DES_ROUND@ --- *
  46  *
  47  * This is the basic DES round function.  The inputs are the two subkey
  48  * halves, and the left and right block halves.  Note that the block halves
  49  * are rotated left one place at this point.  This wraps what's meant to be
  50  * the top bit around to the bottom, so I get a clear run at the S-boxes.
  51  */
  52
  53 #define DES_ROUND(ka, kb, x, y) do {                                    \
  54   uint32 _t = (y) ^ (ka);                                               \
  55   (x) ^= des_sp[7][(_t >>  0) & 0x3f] ^                                 \
  56          des_sp[5][(_t >>  8) & 0x3f] ^                                 \
  57          des_sp[3][(_t >> 16) & 0x3f] ^                                 \
  58          des_sp[1][(_t >> 24) & 0x3f];                                  \
  59   _t = ROR32((y), 4) ^ (kb);                                            \
  60   (x) ^= des_sp[6][(_t >>  0) & 0x3f] ^                                 \
  61          des_sp[4][(_t >>  8) & 0x3f] ^                                 \
  62          des_sp[2][(_t >> 16) & 0x3f] ^                                 \
  63          des_sp[0][(_t >> 24) & 0x3f];                                  \
  64 } while (0)
  65
  66 /* --- @DES_IP@, @DES_IPINV@ --- *
  67  *
  68  * The cryptographically useless initial and final permutations.  The initial
  69  * permutation also rotates the two block halves left by one place.  This is
  70  * undone by the inverse permutation at the end.
  71  */
  72
  73 #define DES_IP(x, y) do {                                               \
  74   uint32 _t;                                                            \
  75   _t = (y ^ (x >> 4)) & 0x0f0f0f0f; y ^= _t; x ^= _t << 4;              \
  76   _t = (x ^ (x >> 18)) & 0x00003333; x ^= _t; x ^= _t << 18;            \
  77   _t = (y ^ (y >> 18)) & 0x00003333; y ^= _t; y ^= _t << 18;            \
  78   _t = (x ^ (x >> 9)) & 0x00550055; x ^= _t; x ^= _t << 9;              \
  79   _t = (y ^ (y >> 9)) & 0x00550055; y ^= _t; y ^= _t << 9;              \
  80   _t = (x ^ (x >> 24)) & 0x000000ff; x ^= _t; x ^= _t << 24;            \
  81   _t = (y ^ (y >> 24)) & 0x000000ff; y ^= _t; y ^= _t << 24;            \
  82   _t = (y ^ (x >> 16)) & 0x0000ffff; y ^= _t; x ^= _t << 16;            \
  83   x = ROL32(x, 1); y = ROL32(y, 1);                                     \
  84 } while (0)
  85
  86 #define DES_IPINV(x, y) do {                                            \
  87   uint32 _t;                                                            \
  88   x = ROR32(x, 1); y = ROR32(y, 1);                                     \
  89   _t = (y ^ (x >> 16)) & 0x0000ffff; y ^= _t; x ^= _t << 16;            \
  90   _t = (x ^ (x >> 24)) & 0x000000ff; x ^= _t; x ^= _t << 24;            \
  91   _t = (y ^ (y >> 24)) & 0x000000ff; y ^= _t; y ^= _t << 24;            \
  92   _t = (y ^ (x >> 4)) & 0x0f0f0f0f; y ^= _t; x ^= _t << 4;              \
  93   _t = (x ^ (x >> 18)) & 0x00003333; x ^= _t; x ^= _t << 18;            \
  94   _t = (y ^ (y >> 18)) & 0x00003333; y ^= _t; y ^= _t << 18;            \
  95   _t = (x ^ (x >> 9)) & 0x00550055; x ^= _t; x ^= _t << 9;              \
  96   _t = (y ^ (y >> 9)) & 0x00550055; y ^= _t; y ^= _t << 9;              \
  97 } while (0)
  98
  99 /* --- @DES_EBLK@, @DES_DBLK@ --- *
 100  *
 101  * Whole block encryption and decryption.
 102  */
 103
 104 #define DES_EBLK(k, a, b, c, d) do {                                    \
 105   const uint32 *_k = (k);                                               \
 106   uint32 _x = (a), _y = (b);                                            \
 107   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 108   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 109   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 110   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 111   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 112   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 113   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 114   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 115   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 116   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 117   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 118   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 119   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 120   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 121   DES_ROUND(_k[0], _k[1], _x, _y); _k += 2;                             \
 122   DES_ROUND(_k[0], _k[1], _y, _x); _k += 2;                             \
 123   (c) = _y;                                                             \
 124   (d) = _x;                                                             \
 125 } while (0)
 126
 127 #define DES_DBLK(k, a, b, c, d) do {                                    \
 128   const uint32 *_k = (k) + 32;                                          \
 129   uint32 _x = (a), _y = (b);                                            \
 130   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 131   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 132   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 133   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 134   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 135   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 136   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 137   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 138   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 139   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 140   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 141   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 142   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 143   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 144   _k -= 2; DES_ROUND(_k[0], _k[1], _x, _y);                             \
 145   _k -= 2; DES_ROUND(_k[0], _k[1], _y, _x);                             \
 146   (c) = _y;                                                             \
 147   (d) = _x;                                                             \
 148 } while (0)
 149
 150 /*----- That's all, folks -------------------------------------------------*/
 151
 152 #ifdef __cplusplus
 153   }
 154 #endif
 155
 156 #endif