src/md5.c

   1 /*
   2   Copyright (C) 1999, 2000, 2002 Aladdin Enterprises.  All rights reserved.
   3
   4   This software is provided 'as-is', without any express or implied
   5   warranty.  In no event will the authors be held liable for any damages
   6   arising from the use of this software.
   7
   8   Permission is granted to anyone to use this software for any purpose,
   9   including commercial applications, and to alter it and redistribute it
  10   freely, subject to the following restrictions:
  11
  12   1. The origin of this software must not be misrepresented; you must not
  13      claim that you wrote the original software. If you use this software
  14      in a product, an acknowledgment in the product documentation would be
  15      appreciated but is not required.
  16   2. Altered source versions must be plainly marked as such, and must not be
  17      misrepresented as being the original software.
  18   3. This notice may not be removed or altered from any source distribution.
  19
  20   L. Peter Deutsch
  21   ghost@aladdin.com
  22
  23  */
  24 /* $Id: md5.c,v 1.6 2002/04/13 19:20:28 lpd Exp $ */
  25 /*
  26   Independent implementation of MD5 (RFC 1321).
  27
  28   This code implements the MD5 Algorithm defined in RFC 1321, whose
  29   text is available at
  30         http://www.ietf.org/rfc/rfc1321.txt
  31   The code is derived from the text of the RFC, including the test suite
  32   (section A.5) but excluding the rest of Appendix A.  It does not include
  33   any code or documentation that is identified in the RFC as being
  34   copyrighted.
  35
  36   The original and principal author of md5.c is L. Peter Deutsch
  37   <ghost@aladdin.com>.  Other authors are noted in the change history
  38   that follows (in reverse chronological order):
  39
  40   2002-04-13 lpd Clarified derivation from RFC 1321; now handles byte order
  41         either statically or dynamically; added missing #include <string.h>
  42         in library.
  43   2002-03-11 lpd Corrected argument list for main(), and added int return
  44         type, in test program and T value program.
  45   2002-02-21 lpd Added missing #include <stdio.h> in test program.
  46   2000-07-03 lpd Patched to eliminate warnings about "constant is
  47         unsigned in ANSI C, signed in traditional"; made test program
  48         self-checking.
  49   1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
  50   1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5).
  51   1999-05-03 lpd Original version.
  52  */
  53
  54 #include "md5.h"
  55 #include <endian.h>
  56 #include <string.h>
  57
  58 #if __BYTE_ORDER == __LITTLE_ENDIAN
  59 # define ARCH_IS_BIG_ENDIAN 0
  60 #elif __BYTE_ORDER == __BIG_ENDIAN
  61 # define ARCH_IS_BIG_ENDIAN 1
  62 #endif
  63
  64 #undef BYTE_ORDER       /* 1 = big-endian, -1 = little-endian, 0 = unknown */
  65 #ifdef ARCH_IS_BIG_ENDIAN
  66 #  define BYTE_ORDER (ARCH_IS_BIG_ENDIAN ? 1 : -1)
  67 #else
  68 #  define BYTE_ORDER 0
  69 #endif
  70
  71 #define T_MASK ((md5_word_t)~0)
  72 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
  73 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
  74 #define T3    0x242070db
  75 #define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
  76 #define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
  77 #define T6    0x4787c62a
  78 #define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
  79 #define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
  80 #define T9    0x698098d8
  81 #define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
  82 #define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
  83 #define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
  84 #define T13    0x6b901122
  85 #define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
  86 #define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
  87 #define T16    0x49b40821
  88 #define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
  89 #define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
  90 #define T19    0x265e5a51
  91 #define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
  92 #define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
  93 #define T22    0x02441453
  94 #define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
  95 #define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
  96 #define T25    0x21e1cde6
  97 #define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
  98 #define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
  99 #define T28    0x455a14ed
 100 #define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
 101 #define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
 102 #define T31    0x676f02d9
 103 #define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
 104 #define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
 105 #define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
 106 #define T35    0x6d9d6122
 107 #define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
 108 #define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
 109 #define T38    0x4bdecfa9
 110 #define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
 111 #define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
 112 #define T41    0x289b7ec6
 113 #define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
 114 #define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
 115 #define T44    0x04881d05
 116 #define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
 117 #define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
 118 #define T47    0x1fa27cf8
 119 #define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
 120 #define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
 121 #define T50    0x432aff97
 122 #define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
 123 #define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
 124 #define T53    0x655b59c3
 125 #define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
 126 #define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
 127 #define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
 128 #define T57    0x6fa87e4f
 129 #define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
 130 #define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
 131 #define T60    0x4e0811a1
 132 #define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
 133 #define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
 134 #define T63    0x2ad7d2bb
 135 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
 136
 137
 138 static void
 139 md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/)
 140 {
 141     md5_word_t
 142         a = pms->abcd[0], b = pms->abcd[1],
 143         c = pms->abcd[2], d = pms->abcd[3];
 144     md5_word_t t;
 145 #if BYTE_ORDER > 0
 146     /* Define storage only for big-endian CPUs. */
 147     md5_word_t X[16];
 148 #else
 149     /* Define storage for little-endian or both types of CPUs. */
 150     md5_word_t xbuf[16];
 151     const md5_word_t *X;
 152 #endif
 153
 154     {
 155 #if BYTE_ORDER == 0
 156         /*
 157          * Determine dynamically whether this is a big-endian or
 158          * little-endian machine, since we can use a more efficient
 159          * algorithm on the latter.
 160          */
 161         static const int w = 1;
 162
 163         if (*((const md5_byte_t *)&w)) /* dynamic little-endian */
 164 #endif
 165 #if BYTE_ORDER <= 0             /* little-endian */
 166         {
 167             /*
 168              * On little-endian machines, we can process properly aligned
 169              * data without copying it.
 170              */
 171             if (!((data - (const md5_byte_t *)0) & 3)) {
 172                 /* data are properly aligned */
 173                 X = (const md5_word_t *)data;
 174             } else {
 175                 /* not aligned */
 176                 memcpy(xbuf, data, 64);
 177                 X = xbuf;
 178             }
 179         }
 180 #endif
 181 #if BYTE_ORDER == 0
 182         else                    /* dynamic big-endian */
 183 #endif
 184 #if BYTE_ORDER >= 0             /* big-endian */
 185         {
 186             /*
 187              * On big-endian machines, we must arrange the bytes in the
 188              * right order.
 189              */
 190             const md5_byte_t *xp = data;
 191             int i;
 192
 193 #  if BYTE_ORDER == 0
 194             X = xbuf;           /* (dynamic only) */
 195 #  else
 196 #    define xbuf X              /* (static only) */
 197 #  endif
 198             for (i = 0; i < 16; ++i, xp += 4)
 199                 xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
 200         }
 201 #endif
 202     }
 203
 204 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
 205
 206     /* Round 1. */
 207     /* Let [abcd k s i] denote the operation
 208        a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
 209 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
 210 #define SET(a, b, c, d, k, s, Ti)\
 211   t = a + F(b,c,d) + X[k] + Ti;\
 212   a = ROTATE_LEFT(t, s) + b
 213     /* Do the following 16 operations. */
 214     SET(a, b, c, d,  0,  7,  T1);
 215     SET(d, a, b, c,  1, 12,  T2);
 216     SET(c, d, a, b,  2, 17,  T3);
 217     SET(b, c, d, a,  3, 22,  T4);
 218     SET(a, b, c, d,  4,  7,  T5);
 219     SET(d, a, b, c,  5, 12,  T6);
 220     SET(c, d, a, b,  6, 17,  T7);
 221     SET(b, c, d, a,  7, 22,  T8);
 222     SET(a, b, c, d,  8,  7,  T9);
 223     SET(d, a, b, c,  9, 12, T10);
 224     SET(c, d, a, b, 10, 17, T11);
 225     SET(b, c, d, a, 11, 22, T12);
 226     SET(a, b, c, d, 12,  7, T13);
 227     SET(d, a, b, c, 13, 12, T14);
 228     SET(c, d, a, b, 14, 17, T15);
 229     SET(b, c, d, a, 15, 22, T16);
 230 #undef SET
 231
 232      /* Round 2. */
 233      /* Let [abcd k s i] denote the operation
 234           a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
 235 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
 236 #define SET(a, b, c, d, k, s, Ti)\
 237   t = a + G(b,c,d) + X[k] + Ti;\
 238   a = ROTATE_LEFT(t, s) + b
 239      /* Do the following 16 operations. */
 240     SET(a, b, c, d,  1,  5, T17);
 241     SET(d, a, b, c,  6,  9, T18);
 242     SET(c, d, a, b, 11, 14, T19);
 243     SET(b, c, d, a,  0, 20, T20);
 244     SET(a, b, c, d,  5,  5, T21);
 245     SET(d, a, b, c, 10,  9, T22);
 246     SET(c, d, a, b, 15, 14, T23);
 247     SET(b, c, d, a,  4, 20, T24);
 248     SET(a, b, c, d,  9,  5, T25);
 249     SET(d, a, b, c, 14,  9, T26);
 250     SET(c, d, a, b,  3, 14, T27);
 251     SET(b, c, d, a,  8, 20, T28);
 252     SET(a, b, c, d, 13,  5, T29);
 253     SET(d, a, b, c,  2,  9, T30);
 254     SET(c, d, a, b,  7, 14, T31);
 255     SET(b, c, d, a, 12, 20, T32);
 256 #undef SET
 257
 258      /* Round 3. */
 259      /* Let [abcd k s t] denote the operation
 260           a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
 261 #define H(x, y, z) ((x) ^ (y) ^ (z))
 262 #define SET(a, b, c, d, k, s, Ti)\
 263   t = a + H(b,c,d) + X[k] + Ti;\
 264   a = ROTATE_LEFT(t, s) + b
 265      /* Do the following 16 operations. */
 266     SET(a, b, c, d,  5,  4, T33);
 267     SET(d, a, b, c,  8, 11, T34);
 268     SET(c, d, a, b, 11, 16, T35);
 269     SET(b, c, d, a, 14, 23, T36);
 270     SET(a, b, c, d,  1,  4, T37);
 271     SET(d, a, b, c,  4, 11, T38);
 272     SET(c, d, a, b,  7, 16, T39);
 273     SET(b, c, d, a, 10, 23, T40);
 274     SET(a, b, c, d, 13,  4, T41);
 275     SET(d, a, b, c,  0, 11, T42);
 276     SET(c, d, a, b,  3, 16, T43);
 277     SET(b, c, d, a,  6, 23, T44);
 278     SET(a, b, c, d,  9,  4, T45);
 279     SET(d, a, b, c, 12, 11, T46);
 280     SET(c, d, a, b, 15, 16, T47);
 281     SET(b, c, d, a,  2, 23, T48);
 282 #undef SET
 283
 284      /* Round 4. */
 285      /* Let [abcd k s t] denote the operation
 286           a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
 287 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
 288 #define SET(a, b, c, d, k, s, Ti)\
 289   t = a + I(b,c,d) + X[k] + Ti;\
 290   a = ROTATE_LEFT(t, s) + b
 291      /* Do the following 16 operations. */
 292     SET(a, b, c, d,  0,  6, T49);
 293     SET(d, a, b, c,  7, 10, T50);
 294     SET(c, d, a, b, 14, 15, T51);
 295     SET(b, c, d, a,  5, 21, T52);
 296     SET(a, b, c, d, 12,  6, T53);
 297     SET(d, a, b, c,  3, 10, T54);
 298     SET(c, d, a, b, 10, 15, T55);
 299     SET(b, c, d, a,  1, 21, T56);
 300     SET(a, b, c, d,  8,  6, T57);
 301     SET(d, a, b, c, 15, 10, T58);
 302     SET(c, d, a, b,  6, 15, T59);
 303     SET(b, c, d, a, 13, 21, T60);
 304     SET(a, b, c, d,  4,  6, T61);
 305     SET(d, a, b, c, 11, 10, T62);
 306     SET(c, d, a, b,  2, 15, T63);
 307     SET(b, c, d, a,  9, 21, T64);
 308 #undef SET
 309
 310      /* Then perform the following additions. (That is increment each
 311         of the four registers by the value it had before this block
 312         was started.) */
 313     pms->abcd[0] += a;
 314     pms->abcd[1] += b;
 315     pms->abcd[2] += c;
 316     pms->abcd[3] += d;
 317 }
 318
 319 void
 320 md5_init(md5_state_t *pms)
 321 {
 322     pms->count[0] = pms->count[1] = 0;
 323     pms->abcd[0] = 0x67452301;
 324     pms->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
 325     pms->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
 326     pms->abcd[3] = 0x10325476;
 327 }
 328
 329 void
 330 md5_append(md5_state_t *pms, const md5_byte_t *data, int nbytes)
 331 {
 332     const md5_byte_t *p = data;
 333     int left = nbytes;
 334     int offset = (pms->count[0] >> 3) & 63;
 335     md5_word_t nbits = (md5_word_t)(nbytes << 3);
 336
 337     if (nbytes <= 0)
 338         return;
 339
 340     /* Update the message length. */
 341     pms->count[1] += nbytes >> 29;
 342     pms->count[0] += nbits;
 343     if (pms->count[0] < nbits)
 344         pms->count[1]++;
 345
 346     /* Process an initial partial block. */
 347     if (offset) {
 348         int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
 349
 350         memcpy(pms->buf + offset, p, copy);
 351         if (offset + copy < 64)
 352             return;
 353         p += copy;
 354         left -= copy;
 355         md5_process(pms, pms->buf);
 356     }
 357
 358     /* Process full blocks. */
 359     for (; left >= 64; p += 64, left -= 64)
 360         md5_process(pms, p);
 361
 362     /* Process a final partial block. */
 363     if (left)
 364         memcpy(pms->buf, p, left);
 365 }
 366
 367 void
 368 md5_finish(md5_state_t *pms, md5_byte_t digest[16])
 369 {
 370     static const md5_byte_t pad[64] = {
 371         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 372         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 373         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 374         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 375     };
 376     md5_byte_t data[8];
 377     int i;
 378
 379     /* Save the length before padding. */
 380     for (i = 0; i < 8; ++i)
 381         data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
 382     /* Pad to 56 bytes mod 64. */
 383     md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
 384     /* Append the length. */
 385     md5_append(pms, data, 8);
 386     for (i = 0; i < 16; ++i)
 387         digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
 388 }