source/libsmb/smbdes.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4
   5    a partial implementation of DES designed for use in the
   6    SMB authentication protocol
   7
   8    Copyright (C) Andrew Tridgell 1997
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25
  26 /* NOTES:
  27
  28    This code makes no attempt to be fast! In fact, it is a very
  29    slow implementation
  30
  31    This code is NOT a complete DES implementation. It implements only
  32    the minimum necessary for SMB authentication, as used by all SMB
  33    products (including every copy of Microsoft Windows95 ever sold)
  34
  35    In particular, it can only do a unchained forward DES pass. This
  36    means it is not possible to use this code for encryption/decryption
  37    of data, instead it is only useful as a "hash" algorithm.
  38
  39    There is no entry point into this code that allows normal DES operation.
  40
  41    I believe this means that this code does not come under ITAR
  42    regulations but this is NOT a legal opinion. If you are concerned
  43    about the applicability of ITAR regulations to this code then you
  44    should confirm it for yourself (and maybe let me know if you come
  45    up with a different answer to the one above)
  46 */
  47
  48
  49
  50 static int perm1[56] = {57, 49, 41, 33, 25, 17,  9,
  51                          1, 58, 50, 42, 34, 26, 18,
  52                         10,  2, 59, 51, 43, 35, 27,
  53                         19, 11,  3, 60, 52, 44, 36,
  54                         63, 55, 47, 39, 31, 23, 15,
  55                          7, 62, 54, 46, 38, 30, 22,
  56                         14,  6, 61, 53, 45, 37, 29,
  57                         21, 13,  5, 28, 20, 12,  4};
  58
  59 static int perm2[48] = {14, 17, 11, 24,  1,  5,
  60                          3, 28, 15,  6, 21, 10,
  61                         23, 19, 12,  4, 26,  8,
  62                         16,  7, 27, 20, 13,  2,
  63                         41, 52, 31, 37, 47, 55,
  64                         30, 40, 51, 45, 33, 48,
  65                         44, 49, 39, 56, 34, 53,
  66                         46, 42, 50, 36, 29, 32};
  67
  68 static int perm3[64] = {58, 50, 42, 34, 26, 18, 10,  2,
  69                         60, 52, 44, 36, 28, 20, 12,  4,
  70                         62, 54, 46, 38, 30, 22, 14,  6,
  71                         64, 56, 48, 40, 32, 24, 16,  8,
  72                         57, 49, 41, 33, 25, 17,  9,  1,
  73                         59, 51, 43, 35, 27, 19, 11,  3,
  74                         61, 53, 45, 37, 29, 21, 13,  5,
  75                         63, 55, 47, 39, 31, 23, 15,  7};
  76
  77 static int perm4[48] = {   32,  1,  2,  3,  4,  5,
  78                             4,  5,  6,  7,  8,  9,
  79                             8,  9, 10, 11, 12, 13,
  80                            12, 13, 14, 15, 16, 17,
  81                            16, 17, 18, 19, 20, 21,
  82                            20, 21, 22, 23, 24, 25,
  83                            24, 25, 26, 27, 28, 29,
  84                            28, 29, 30, 31, 32,  1};
  85
  86 static int perm5[32] = {      16,  7, 20, 21,
  87                               29, 12, 28, 17,
  88                                1, 15, 23, 26,
  89                                5, 18, 31, 10,
  90                                2,  8, 24, 14,
  91                               32, 27,  3,  9,
  92                               19, 13, 30,  6,
  93                               22, 11,  4, 25};
  94
  95
  96 static int perm6[64] ={ 40,  8, 48, 16, 56, 24, 64, 32,
  97                         39,  7, 47, 15, 55, 23, 63, 31,
  98                         38,  6, 46, 14, 54, 22, 62, 30,
  99                         37,  5, 45, 13, 53, 21, 61, 29,
 100                         36,  4, 44, 12, 52, 20, 60, 28,
 101                         35,  3, 43, 11, 51, 19, 59, 27,
 102                         34,  2, 42, 10, 50, 18, 58, 26,
 103                         33,  1, 41,  9, 49, 17, 57, 25};
 104
 105
 106 static int sc[16] = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};
 107
 108 static int sbox[8][4][16] = {
 109         {{14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7},
 110          {0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8},
 111          {4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0},
 112          {15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13}},
 113
 114         {{15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10},
 115          {3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5},
 116          {0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15},
 117          {13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9}},
 118
 119         {{10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8},
 120          {13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1},
 121          {13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7},
 122          {1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12}},
 123
 124         {{7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15},
 125          {13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9},
 126          {10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4},
 127          {3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14}},
 128
 129         {{2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9},
 130          {14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6},
 131          {4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14},
 132          {11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3}},
 133
 134         {{12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11},
 135          {10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8},
 136          {9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6},
 137          {4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13}},
 138
 139         {{4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1},
 140          {13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6},
 141          {1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2},
 142          {6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12}},
 143
 144         {{13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7},
 145          {1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2},
 146          {7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8},
 147          {2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11}}};
 148
 149 static void permute(char *out, char *in, int *p, int n)
 150 {
 151         int i;
 152         for (i=0;i<n;i++)
 153                 out[i] = in[p[i]-1];
 154 }
 155
 156 static void lshift(char *d, int count, int n)
 157 {
 158         char out[64];
 159         int i;
 160         for (i=0;i<n;i++)
 161                 out[i] = d[(i+count)%n];
 162         for (i=0;i<n;i++)
 163                 d[i] = out[i];
 164 }
 165
 166 static void concat(char *out, char *in1, char *in2, int l1, int l2)
 167 {
 168         while (l1--)
 169                 *out++ = *in1++;
 170         while (l2--)
 171                 *out++ = *in2++;
 172 }
 173
 174 static void xor(char *out, char *in1, char *in2, int n)
 175 {
 176         int i;
 177         for (i=0;i<n;i++)
 178                 out[i] = in1[i] ^ in2[i];
 179 }
 180
 181 static void dohash(char *out, char *in, char *key)
 182 {
 183         int i, j, k;
 184         char pk1[56];
 185         char c[28];
 186         char d[28];
 187         char cd[56];
 188         char ki[16][48];
 189         char pd1[64];
 190         char l[32], r[32];
 191         char rl[64];
 192
 193         permute(pk1, key, perm1, 56);
 194
 195         for (i=0;i<28;i++)
 196                 c[i] = pk1[i];
 197         for (i=0;i<28;i++)
 198                 d[i] = pk1[i+28];
 199
 200         for (i=0;i<16;i++) {
 201                 lshift(c, sc[i], 28);
 202                 lshift(d, sc[i], 28);
 203
 204                 concat(cd, c, d, 28, 28);
 205                 permute(ki[i], cd, perm2, 48);
 206         }
 207
 208         permute(pd1, in, perm3, 64);
 209
 210         for (j=0;j<32;j++) {
 211                 l[j] = pd1[j];
 212                 r[j] = pd1[j+32];
 213         }
 214
 215         for (i=0;i<16;i++) {
 216                 char er[48];
 217                 char erk[48];
 218                 char b[8][6];
 219                 char cb[32];
 220                 char pcb[32];
 221                 char r2[32];
 222
 223                 permute(er, r, perm4, 48);
 224
 225                 xor(erk, er, ki[i], 48);
 226
 227                 for (j=0;j<8;j++)
 228                         for (k=0;k<6;k++)
 229                                 b[j][k] = erk[j*6 + k];
 230
 231                 for (j=0;j<8;j++) {
 232                         int m, n;
 233                         m = (b[j][0]<<1) | b[j][5];
 234
 235                         n = (b[j][1]<<3) | (b[j][2]<<2) | (b[j][3]<<1) | b[j][4];
 236
 237                         for (k=0;k<4;k++)
 238                                 b[j][k] = (sbox[j][m][n] & (1<<(3-k)))?1:0;
 239                 }
 240
 241                 for (j=0;j<8;j++)
 242                         for (k=0;k<4;k++)
 243                                 cb[j*4+k] = b[j][k];
 244                 permute(pcb, cb, perm5, 32);
 245
 246                 xor(r2, l, pcb, 32);
 247
 248                 for (j=0;j<32;j++)
 249                         l[j] = r[j];
 250
 251                 for (j=0;j<32;j++)
 252                         r[j] = r2[j];
 253         }
 254
 255         concat(rl, r, l, 32, 32);
 256
 257         permute(out, rl, perm6, 64);
 258 }
 259
 260 static void str_to_key(unsigned char *str,unsigned char *key)
 261 {
 262         int i;
 263
 264         key[0] = str[0]>>1;
 265         key[1] = ((str[0]&0x01)<<6) | (str[1]>>2);
 266         key[2] = ((str[1]&0x03)<<5) | (str[2]>>3);
 267         key[3] = ((str[2]&0x07)<<4) | (str[3]>>4);
 268         key[4] = ((str[3]&0x0F)<<3) | (str[4]>>5);
 269         key[5] = ((str[4]&0x1F)<<2) | (str[5]>>6);
 270         key[6] = ((str[5]&0x3F)<<1) | (str[6]>>7);
 271         key[7] = str[6]&0x7F;
 272         for (i=0;i<8;i++) {
 273                 key[i] = (key[i]<<1);
 274         }
 275 }
 276
 277
 278 static void smbhash(unsigned char *out, unsigned char *in, unsigned char *key)
 279 {
 280         int i;
 281         char outb[64];
 282         char inb[64];
 283         char keyb[64];
 284         unsigned char key2[8];
 285
 286         str_to_key(key, key2);
 287
 288         for (i=0;i<64;i++) {
 289                 inb[i] = (in[i/8] & (1<<(7-(i%8)))) ? 1 : 0;
 290                 keyb[i] = (key2[i/8] & (1<<(7-(i%8)))) ? 1 : 0;
 291                 outb[i] = 0;
 292         }
 293
 294         dohash(outb, inb, keyb);
 295
 296         for (i=0;i<8;i++) {
 297                 out[i] = 0;
 298         }
 299
 300         for (i=0;i<64;i++) {
 301                 if (outb[i])
 302                         out[i/8] |= (1<<(7-(i%8)));
 303         }
 304 }
 305
 306 void E_P16(unsigned char *p14,unsigned char *p16)
 307 {
 308         unsigned char sp8[8] = {0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25};
 309         smbhash(p16, sp8, p14);
 310         smbhash(p16+8, sp8, p14+7);
 311 }
 312
 313 void E_P24(unsigned char *p21, unsigned char *c8, unsigned char *p24)
 314 {
 315         smbhash(p24, c8, p21);
 316         smbhash(p24+8, c8, p21+7);
 317         smbhash(p24+16, c8, p21+14);
 318 }
 319
 320