armsrc/des.c

   1 /* des.c */
   2 /*
   3     This file is part of the ARM-Crypto-Lib.
   4     Copyright (C) 2006-2010  Daniel Otte (daniel.otte@rub.de)
   5
   6     This program is free software: you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation, either version 3 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19 /**
  20  * \file     des.c
  21  * \author   Daniel Otte
  22  * \email    daniel.otte@rub.de
  23  * \date     2007-06-16
  24  * \brief    DES and EDE-DES implementation
  25  * \license      GPLv3 or later
  26  *
  27  */
  28 #include <stdint.h>
  29 #include <string.h>
  30
  31 const uint8_t sbox[256]  = {
  32   /* S-box 1 */
  33   0xE4, 0xD1, 0x2F, 0xB8, 0x3A, 0x6C, 0x59, 0x07,
  34   0x0F, 0x74, 0xE2, 0xD1, 0xA6, 0xCB, 0x95, 0x38,
  35   0x41, 0xE8, 0xD6, 0x2B, 0xFC, 0x97, 0x3A, 0x50,
  36   0xFC, 0x82, 0x49, 0x17, 0x5B, 0x3E, 0xA0, 0x6D,
  37   /* S-box 2 */
  38   0xF1, 0x8E, 0x6B, 0x34, 0x97, 0x2D, 0xC0, 0x5A,
  39   0x3D, 0x47, 0xF2, 0x8E, 0xC0, 0x1A, 0x69, 0xB5,
  40   0x0E, 0x7B, 0xA4, 0xD1, 0x58, 0xC6, 0x93, 0x2F,
  41   0xD8, 0xA1, 0x3F, 0x42, 0xB6, 0x7C, 0x05, 0xE9,
  42   /* S-box 3 */
  43   0xA0, 0x9E, 0x63, 0xF5, 0x1D, 0xC7, 0xB4, 0x28,
  44   0xD7, 0x09, 0x34, 0x6A, 0x28, 0x5E, 0xCB, 0xF1,
  45   0xD6, 0x49, 0x8F, 0x30, 0xB1, 0x2C, 0x5A, 0xE7,
  46   0x1A, 0xD0, 0x69, 0x87, 0x4F, 0xE3, 0xB5, 0x2C,
  47   /* S-box 4 */
  48   0x7D, 0xE3, 0x06, 0x9A, 0x12, 0x85, 0xBC, 0x4F,
  49   0xD8, 0xB5, 0x6F, 0x03, 0x47, 0x2C, 0x1A, 0xE9,
  50   0xA6, 0x90, 0xCB, 0x7D, 0xF1, 0x3E, 0x52, 0x84,
  51   0x3F, 0x06, 0xA1, 0xD8, 0x94, 0x5B, 0xC7, 0x2E,
  52   /* S-box 5 */
  53   0x2C, 0x41, 0x7A, 0xB6, 0x85, 0x3F, 0xD0, 0xE9,
  54   0xEB, 0x2C, 0x47, 0xD1, 0x50, 0xFA, 0x39, 0x86,
  55   0x42, 0x1B, 0xAD, 0x78, 0xF9, 0xC5, 0x63, 0x0E,
  56   0xB8, 0xC7, 0x1E, 0x2D, 0x6F, 0x09, 0xA4, 0x53,
  57   /* S-box 6 */
  58   0xC1, 0xAF, 0x92, 0x68, 0x0D, 0x34, 0xE7, 0x5B,
  59   0xAF, 0x42, 0x7C, 0x95, 0x61, 0xDE, 0x0B, 0x38,
  60   0x9E, 0xF5, 0x28, 0xC3, 0x70, 0x4A, 0x1D, 0xB6,
  61   0x43, 0x2C, 0x95, 0xFA, 0xBE, 0x17, 0x60, 0x8D,
  62   /* S-box 7 */
  63   0x4B, 0x2E, 0xF0, 0x8D, 0x3C, 0x97, 0x5A, 0x61,
  64   0xD0, 0xB7, 0x49, 0x1A, 0xE3, 0x5C, 0x2F, 0x86,
  65   0x14, 0xBD, 0xC3, 0x7E, 0xAF, 0x68, 0x05, 0x92,
  66   0x6B, 0xD8, 0x14, 0xA7, 0x95, 0x0F, 0xE2, 0x3C,
  67   /* S-box 8 */
  68   0xD2, 0x84, 0x6F, 0xB1, 0xA9, 0x3E, 0x50, 0xC7,
  69   0x1F, 0xD8, 0xA3, 0x74, 0xC5, 0x6B, 0x0E, 0x92,
  70   0x7B, 0x41, 0x9C, 0xE2, 0x06, 0xAD, 0xF3, 0x58,
  71   0x21, 0xE7, 0x4A, 0x8D, 0xFC, 0x90, 0x35, 0x6B
  72 };
  73
  74 const uint8_t e_permtab[] ={
  75          4,  6,                                         /* 4 bytes in 6 bytes out*/
  76         32,  1,  2,  3,  4,  5,
  77          4,  5,  6,  7,  8,  9,
  78          8,  9, 10, 11, 12, 13,
  79         12, 13, 14, 15, 16, 17,
  80         16, 17, 18, 19, 20, 21,
  81         20, 21, 22, 23, 24, 25,
  82         24, 25, 26, 27, 28, 29,
  83         28, 29, 30, 31, 32,  1
  84 };
  85
  86 const uint8_t p_permtab[] ={
  87          4,  4,                                         /* 32 bit -> 32 bit */
  88         16,  7, 20, 21,
  89         29, 12, 28, 17,
  90          1, 15, 23, 26,
  91          5, 18, 31, 10,
  92          2,  8, 24, 14,
  93         32, 27,  3,  9,
  94         19, 13, 30,  6,
  95         22, 11,  4, 25
  96 };
  97
  98 const uint8_t ip_permtab[] ={
  99          8,  8,                                         /* 64 bit -> 64 bit */
 100         58, 50, 42, 34, 26, 18, 10, 2,
 101         60, 52, 44, 36, 28, 20, 12, 4,
 102         62, 54, 46, 38, 30, 22, 14, 6,
 103         64, 56, 48, 40, 32, 24, 16, 8,
 104         57, 49, 41, 33, 25, 17,  9, 1,
 105         59, 51, 43, 35, 27, 19, 11, 3,
 106         61, 53, 45, 37, 29, 21, 13, 5,
 107         63, 55, 47, 39, 31, 23, 15, 7
 108 };
 109
 110 const uint8_t inv_ip_permtab[] ={
 111          8, 8,                                          /* 64 bit -> 64 bit */
 112         40, 8, 48, 16, 56, 24, 64, 32,
 113         39, 7, 47, 15, 55, 23, 63, 31,
 114         38, 6, 46, 14, 54, 22, 62, 30,
 115         37, 5, 45, 13, 53, 21, 61, 29,
 116         36, 4, 44, 12, 52, 20, 60, 28,
 117         35, 3, 43, 11, 51, 19, 59, 27,
 118         34, 2, 42, 10, 50, 18, 58, 26,
 119         33, 1, 41,  9, 49, 17, 57, 25
 120 };
 121
 122 const uint8_t pc1_permtab[] ={
 123          8,  7,                                         /* 64 bit -> 56 bit*/
 124         57, 49, 41, 33, 25, 17,  9,
 125          1, 58, 50, 42, 34, 26, 18,
 126         10,  2, 59, 51, 43, 35, 27,
 127         19, 11,  3, 60, 52, 44, 36,
 128         63, 55, 47, 39, 31, 23, 15,
 129          7, 62, 54, 46, 38, 30, 22,
 130         14,  6, 61, 53, 45, 37, 29,
 131         21, 13,  5, 28, 20, 12,  4
 132 };
 133
 134 const uint8_t pc2_permtab[] ={
 135          7,      6,                                     /* 56 bit -> 48 bit */
 136         14, 17, 11, 24,  1,  5,
 137          3, 28, 15,  6, 21, 10,
 138         23, 19, 12,  4, 26,  8,
 139         16,  7, 27, 20, 13,  2,
 140         41, 52, 31, 37, 47, 55,
 141         30, 40, 51, 45, 33, 48,
 142         44, 49, 39, 56, 34, 53,
 143         46, 42, 50, 36, 29, 32
 144 };
 145
 146 const uint8_t splitin6bitword_permtab[] = {
 147          8,  8,                                         /* 64 bit -> 64 bit */
 148         64, 64,  1,  6,  2,  3,  4,  5,
 149         64, 64,  7, 12,  8,  9, 10, 11,
 150         64, 64, 13, 18, 14, 15, 16, 17,
 151         64, 64, 19, 24, 20, 21, 22, 23,
 152         64, 64, 25, 30, 26, 27, 28, 29,
 153         64, 64, 31, 36, 32, 33, 34, 35,
 154         64, 64, 37, 42, 38, 39, 40, 41,
 155         64, 64, 43, 48, 44, 45, 46, 47
 156 };
 157
 158 const uint8_t shiftkey_permtab[] = {
 159          7,  7,                                         /* 56 bit -> 56 bit */
 160          2,  3,  4,  5,  6,  7,  8,  9,
 161         10, 11, 12, 13, 14, 15, 16, 17,
 162         18, 19, 20, 21, 22, 23, 24, 25,
 163         26, 27, 28,  1,
 164         30, 31, 32, 33, 34, 35, 36, 37,
 165         38, 39, 40, 41, 42, 43, 44, 45,
 166         46, 47, 48, 49, 50, 51, 52, 53,
 167         54, 55, 56, 29
 168 };
 169
 170 const uint8_t shiftkeyinv_permtab[] = {
 171          7,  7,
 172         28,  1,  2,  3,  4,  5,  6,  7,
 173          8,  9, 10, 11, 12, 13, 14, 15,
 174         16, 17, 18, 19, 20, 21, 22, 23,
 175         24, 25, 26, 27,
 176         56, 29, 30, 31, 32, 33, 34, 35,
 177         36, 37, 38, 39, 40, 41, 42, 43,
 178         44, 45, 46, 47, 48, 49, 50, 51,
 179         52, 53, 54, 55
 180 };
 181
 182 /*
 183 1 0
 184 1 0
 185 2 1
 186 2 1
 187 2 1
 188 2 1
 189 2 1
 190 2 1
 191 ----
 192 1 0
 193 2 1
 194 2 1
 195 2 1
 196 2 1
 197 2 1
 198 2 1
 199 1 0
 200 */
 201 #define ROTTABLE      0x7EFC
 202 #define ROTTABLE_INV  0x3F7E
 203 /******************************************************************************/
 204
 205 void permute(const uint8_t *ptable, const uint8_t *in, uint8_t *out){
 206         uint8_t ob; /* in-bytes and out-bytes */
 207         uint8_t byte, bit; /* counter for bit and byte */
 208         ob = ptable[1];
 209         ptable = &(ptable[2]);
 210         for(byte=0; byte<ob; ++byte){
 211                 uint8_t x,t=0;
 212                 for(bit=0; bit<8; ++bit){
 213                         x=*ptable++ -1 ;
 214                                 t<<=1;
 215                         if((in[x/8]) & (0x80>>(x%8)) ){
 216                                 t|=0x01;
 217                         }
 218                 }
 219                 out[byte]=t;
 220         }
 221 }
 222
 223 /******************************************************************************/
 224
 225 void changeendian32(uint32_t * a){
 226         *a = (*a & 0x000000FF) << 24 |
 227                  (*a & 0x0000FF00) <<  8 |
 228                  (*a & 0x00FF0000) >>  8 |
 229                  (*a & 0xFF000000) >> 24;
 230 }
 231
 232 /******************************************************************************/
 233 static inline
 234 void shiftkey(uint8_t *key){
 235         uint8_t k[7];
 236         memcpy(k, key, 7);
 237         permute((uint8_t*)shiftkey_permtab, k, key);
 238 }
 239
 240 /******************************************************************************/
 241 static inline
 242 void shiftkey_inv(uint8_t *key){
 243         uint8_t k[7];
 244         memcpy(k, key, 7);
 245         permute((uint8_t*)shiftkeyinv_permtab, k, key);
 246
 247 }
 248
 249 /******************************************************************************/
 250 static inline
 251 uint64_t splitin6bitwords(uint64_t a){
 252         uint64_t ret=0;
 253         a &= 0x0000ffffffffffffLL;
 254         permute((uint8_t*)splitin6bitword_permtab, (uint8_t*)&a, (uint8_t*)&ret);
 255         return ret;
 256 }
 257
 258 /******************************************************************************/
 259
 260 static inline
 261 uint8_t substitute(uint8_t a, uint8_t * sbp){
 262         uint8_t x;
 263         x = sbp[a>>1];
 264         x = (a&1)?x&0x0F:x>>4;
 265         return x;
 266
 267 }
 268
 269 /******************************************************************************/
 270
 271 uint32_t des_f(uint32_t r, uint8_t* kr){
 272         uint8_t i;
 273         uint32_t t=0,ret;
 274         uint64_t data;
 275         uint8_t *sbp; /* sboxpointer */
 276         permute((uint8_t*)e_permtab, (uint8_t*)&r, (uint8_t*)&data);
 277         for(i=0; i<7; ++i)
 278                 ((uint8_t*)&data)[i] ^= kr[i];
 279
 280         /* Sbox substitution */
 281         data = splitin6bitwords(data);
 282         sbp=(uint8_t*)sbox;
 283         for(i=0; i<8; ++i){
 284                 uint8_t x;
 285                 x = substitute(((uint8_t*)&data)[i], sbp);
 286                 t<<=4;
 287                 t |= x;
 288                 sbp += 32;
 289         }
 290         changeendian32(&t);
 291
 292         permute((uint8_t*)p_permtab,(uint8_t*)&t, (uint8_t*)&ret);
 293
 294         return ret;
 295 }
 296
 297 /******************************************************************************/
 298
 299 void des_enc(void* out, const void* in, const void* key){
 300 #define R *((uint32_t*)&(data[4]))
 301 #define L *((uint32_t*)&(data[0]))
 302
 303         uint8_t data[8],kr[6],k[7];
 304         uint8_t i;
 305
 306         permute((uint8_t*)ip_permtab, (uint8_t*)in, data);
 307         permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);
 308         for(i=0; i<8; ++i){
 309                 shiftkey(k);
 310                 if(ROTTABLE&((1<<((i<<1)+0))) )
 311                         shiftkey(k);
 312                 permute((uint8_t*)pc2_permtab, k, kr);
 313                 L ^= des_f(R, kr);
 314
 315                 shiftkey(k);
 316                 if(ROTTABLE&((1<<((i<<1)+1))) )
 317                         shiftkey(k);
 318                 permute((uint8_t*)pc2_permtab, k, kr);
 319                 R ^= des_f(L, kr);
 320
 321         }
 322         /* L <-> R*/
 323         R ^= L;
 324         L ^= R;
 325         R ^= L;
 326
 327         permute((uint8_t*)inv_ip_permtab, data, (uint8_t*)out);
 328 }
 329
 330 /******************************************************************************/
 331
 332 void des_dec(void* out, const void* in, const uint8_t* key){
 333 #define R *((uint32_t*)&(data[4]))
 334 #define L *((uint32_t*)&(data[0]))
 335
 336         uint8_t data[8],kr[6],k[7];
 337         int8_t i;
 338         permute((uint8_t*)ip_permtab, (uint8_t*)in, data);
 339         permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);
 340         for(i=7; i>=0; --i){
 341
 342                 permute((uint8_t*)pc2_permtab, k, kr);
 343                 L ^= des_f(R, kr);
 344                 shiftkey_inv(k);
 345                 if(ROTTABLE&((1<<((i<<1)+1))) ){
 346                         shiftkey_inv(k);
 347                 }
 348
 349                 permute((uint8_t*)pc2_permtab, k, kr);
 350                 R ^= des_f(L, kr);
 351                 shiftkey_inv(k);
 352                 if(ROTTABLE&((1<<((i<<1)+0))) ){
 353                         shiftkey_inv(k);
 354                 }
 355
 356         }
 357         /* L <-> R*/
 358         R ^= L;
 359         L ^= R;
 360         R ^= L;
 361
 362         permute((uint8_t*)inv_ip_permtab, data, (uint8_t*)out);
 363 }
 364
 365 /******************************************************************************/
 366
 367 void tdes_enc(void* out, void* in, const void* key){
 368         des_enc(out,  in, (uint8_t*)key + 0);
 369         des_dec(out, out, (uint8_t*)key + 8);
 370         des_enc(out, out, (uint8_t*)key +16);
 371 }
 372
 373 /******************************************************************************/
 374
 375 void tdes_dec(void* out, void* in, const uint8_t* key){
 376         des_dec(out,  in, (uint8_t*)key +16);
 377         des_enc(out, out, (uint8_t*)key + 8);
 378         des_dec(out, out, (uint8_t*)key + 0);
 379 }
 380
 381 /******************************************************************************/
 382
 383