Modules/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 <string.h>
  56 #include <limits.h>
  57
  58 #undef BYTE_ORDER       /* 1 = big-endian, -1 = little-endian, 0 = unknown */
  59 #ifdef ARCH_IS_BIG_ENDIAN
  60 #  define BYTE_ORDER (ARCH_IS_BIG_ENDIAN ? 1 : -1)
  61 #else
  62 #  define BYTE_ORDER 0
  63 #endif
  64
  65 #define T_MASK ((md5_word_t)~0)
  66 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
  67 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
  68 #define T3    0x242070db
  69 #define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
  70 #define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
  71 #define T6    0x4787c62a
  72 #define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
  73 #define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
  74 #define T9    0x698098d8
  75 #define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
  76 #define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
  77 #define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
  78 #define T13    0x6b901122
  79 #define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
  80 #define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
  81 #define T16    0x49b40821
  82 #define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
  83 #define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
  84 #define T19    0x265e5a51
  85 #define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
  86 #define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
  87 #define T22    0x02441453
  88 #define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
  89 #define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
  90 #define T25    0x21e1cde6
  91 #define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
  92 #define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
  93 #define T28    0x455a14ed
  94 #define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
  95 #define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
  96 #define T31    0x676f02d9
  97 #define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
  98 #define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
  99 #define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
 100 #define T35    0x6d9d6122
 101 #define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
 102 #define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
 103 #define T38    0x4bdecfa9
 104 #define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
 105 #define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
 106 #define T41    0x289b7ec6
 107 #define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
 108 #define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
 109 #define T44    0x04881d05
 110 #define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
 111 #define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
 112 #define T47    0x1fa27cf8
 113 #define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
 114 #define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
 115 #define T50    0x432aff97
 116 #define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
 117 #define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
 118 #define T53    0x655b59c3
 119 #define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
 120 #define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
 121 #define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
 122 #define T57    0x6fa87e4f
 123 #define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
 124 #define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
 125 #define T60    0x4e0811a1
 126 #define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
 127 #define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
 128 #define T63    0x2ad7d2bb
 129 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
 130
 131
 132 static void
 133 md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/)
 134 {
 135     md5_word_t
 136         a = pms->abcd[0], b = pms->abcd[1],
 137         c = pms->abcd[2], d = pms->abcd[3];
 138     md5_word_t t;
 139 #if BYTE_ORDER > 0
 140     /* Define storage only for big-endian CPUs. */
 141     md5_word_t X[16];
 142 #else
 143     /* Define storage for little-endian or both types of CPUs. */
 144     md5_word_t xbuf[16];
 145     const md5_word_t *X;
 146 #endif
 147
 148     {
 149 #if BYTE_ORDER == 0
 150         /*
 151          * Determine dynamically whether this is a big-endian or
 152          * little-endian machine, since we can use a more efficient
 153          * algorithm on the latter.
 154          */
 155         static const int w = 1;
 156
 157         if (*((const md5_byte_t *)&w)) /* dynamic little-endian */
 158 #endif
 159 #if BYTE_ORDER <= 0             /* little-endian */
 160         {
 161             /*
 162              * On little-endian machines, we can process properly aligned
 163              * data without copying it.
 164              */
 165             if (!((data - (const md5_byte_t *)0) & 3)) {
 166                 /* data are properly aligned */
 167                 X = (const md5_word_t *)data;
 168             } else {
 169                 /* not aligned */
 170                 memcpy(xbuf, data, 64);
 171                 X = xbuf;
 172             }
 173         }
 174 #endif
 175 #if BYTE_ORDER == 0
 176         else                    /* dynamic big-endian */
 177 #endif
 178 #if BYTE_ORDER >= 0             /* big-endian */
 179         {
 180             /*
 181              * On big-endian machines, we must arrange the bytes in the
 182              * right order.
 183              */
 184             const md5_byte_t *xp = data;
 185             int i;
 186
 187 #  if BYTE_ORDER == 0
 188             X = xbuf;           /* (dynamic only) */
 189 #  else
 190 #    define xbuf X              /* (static only) */
 191 #  endif
 192             for (i = 0; i < 16; ++i, xp += 4)
 193                 xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
 194         }
 195 #endif
 196     }
 197
 198 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
 199
 200     /* Round 1. */
 201     /* Let [abcd k s i] denote the operation
 202        a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
 203 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
 204 #define SET(a, b, c, d, k, s, Ti)\
 205   t = a + F(b,c,d) + X[k] + Ti;\
 206   a = ROTATE_LEFT(t, s) + b
 207     /* Do the following 16 operations. */
 208     SET(a, b, c, d,  0,  7,  T1);
 209     SET(d, a, b, c,  1, 12,  T2);
 210     SET(c, d, a, b,  2, 17,  T3);
 211     SET(b, c, d, a,  3, 22,  T4);
 212     SET(a, b, c, d,  4,  7,  T5);
 213     SET(d, a, b, c,  5, 12,  T6);
 214     SET(c, d, a, b,  6, 17,  T7);
 215     SET(b, c, d, a,  7, 22,  T8);
 216     SET(a, b, c, d,  8,  7,  T9);
 217     SET(d, a, b, c,  9, 12, T10);
 218     SET(c, d, a, b, 10, 17, T11);
 219     SET(b, c, d, a, 11, 22, T12);
 220     SET(a, b, c, d, 12,  7, T13);
 221     SET(d, a, b, c, 13, 12, T14);
 222     SET(c, d, a, b, 14, 17, T15);
 223     SET(b, c, d, a, 15, 22, T16);
 224 #undef SET
 225
 226      /* Round 2. */
 227      /* Let [abcd k s i] denote the operation
 228           a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
 229 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
 230 #define SET(a, b, c, d, k, s, Ti)\
 231   t = a + G(b,c,d) + X[k] + Ti;\
 232   a = ROTATE_LEFT(t, s) + b
 233      /* Do the following 16 operations. */
 234     SET(a, b, c, d,  1,  5, T17);
 235     SET(d, a, b, c,  6,  9, T18);
 236     SET(c, d, a, b, 11, 14, T19);
 237     SET(b, c, d, a,  0, 20, T20);
 238     SET(a, b, c, d,  5,  5, T21);
 239     SET(d, a, b, c, 10,  9, T22);
 240     SET(c, d, a, b, 15, 14, T23);
 241     SET(b, c, d, a,  4, 20, T24);
 242     SET(a, b, c, d,  9,  5, T25);
 243     SET(d, a, b, c, 14,  9, T26);
 244     SET(c, d, a, b,  3, 14, T27);
 245     SET(b, c, d, a,  8, 20, T28);
 246     SET(a, b, c, d, 13,  5, T29);
 247     SET(d, a, b, c,  2,  9, T30);
 248     SET(c, d, a, b,  7, 14, T31);
 249     SET(b, c, d, a, 12, 20, T32);
 250 #undef SET
 251
 252      /* Round 3. */
 253      /* Let [abcd k s t] denote the operation
 254           a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
 255 #define H(x, y, z) ((x) ^ (y) ^ (z))
 256 #define SET(a, b, c, d, k, s, Ti)\
 257   t = a + H(b,c,d) + X[k] + Ti;\
 258   a = ROTATE_LEFT(t, s) + b
 259      /* Do the following 16 operations. */
 260     SET(a, b, c, d,  5,  4, T33);
 261     SET(d, a, b, c,  8, 11, T34);
 262     SET(c, d, a, b, 11, 16, T35);
 263     SET(b, c, d, a, 14, 23, T36);
 264     SET(a, b, c, d,  1,  4, T37);
 265     SET(d, a, b, c,  4, 11, T38);
 266     SET(c, d, a, b,  7, 16, T39);
 267     SET(b, c, d, a, 10, 23, T40);
 268     SET(a, b, c, d, 13,  4, T41);
 269     SET(d, a, b, c,  0, 11, T42);
 270     SET(c, d, a, b,  3, 16, T43);
 271     SET(b, c, d, a,  6, 23, T44);
 272     SET(a, b, c, d,  9,  4, T45);
 273     SET(d, a, b, c, 12, 11, T46);
 274     SET(c, d, a, b, 15, 16, T47);
 275     SET(b, c, d, a,  2, 23, T48);
 276 #undef SET
 277
 278      /* Round 4. */
 279      /* Let [abcd k s t] denote the operation
 280           a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
 281 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
 282 #define SET(a, b, c, d, k, s, Ti)\
 283   t = a + I(b,c,d) + X[k] + Ti;\
 284   a = ROTATE_LEFT(t, s) + b
 285      /* Do the following 16 operations. */
 286     SET(a, b, c, d,  0,  6, T49);
 287     SET(d, a, b, c,  7, 10, T50);
 288     SET(c, d, a, b, 14, 15, T51);
 289     SET(b, c, d, a,  5, 21, T52);
 290     SET(a, b, c, d, 12,  6, T53);
 291     SET(d, a, b, c,  3, 10, T54);
 292     SET(c, d, a, b, 10, 15, T55);
 293     SET(b, c, d, a,  1, 21, T56);
 294     SET(a, b, c, d,  8,  6, T57);
 295     SET(d, a, b, c, 15, 10, T58);
 296     SET(c, d, a, b,  6, 15, T59);
 297     SET(b, c, d, a, 13, 21, T60);
 298     SET(a, b, c, d,  4,  6, T61);
 299     SET(d, a, b, c, 11, 10, T62);
 300     SET(c, d, a, b,  2, 15, T63);
 301     SET(b, c, d, a,  9, 21, T64);
 302 #undef SET
 303
 304      /* Then perform the following additions. (That is increment each
 305         of the four registers by the value it had before this block
 306         was started.) */
 307     pms->abcd[0] += a;
 308     pms->abcd[1] += b;
 309     pms->abcd[2] += c;
 310     pms->abcd[3] += d;
 311 }
 312
 313 void
 314 md5_init(md5_state_t *pms)
 315 {
 316     pms->count[0] = pms->count[1] = 0;
 317     pms->abcd[0] = 0x67452301;
 318     pms->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
 319     pms->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
 320     pms->abcd[3] = 0x10325476;
 321 }
 322
 323 void
 324 md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes)
 325 {
 326     const md5_byte_t *p = data;
 327     unsigned int left = nbytes;
 328     unsigned int offset = (pms->count[0] >> 3) & 63;
 329     md5_word_t nbits = (md5_word_t)(nbytes << 3);
 330
 331     if (nbytes <= 0)
 332         return;
 333
 334     /* this special case is handled recursively */
 335     if (nbytes > INT_MAX - offset) {
 336         unsigned int overlap;
 337
 338         /* handle the append in two steps to prevent overflow */
 339         overlap = 64 - offset;
 340
 341         md5_append(pms, data, overlap);
 342         md5_append(pms, data + overlap, nbytes - overlap);
 343         return;
 344     }
 345
 346     /* Update the message length. */
 347     pms->count[1] += nbytes >> 29;
 348     pms->count[0] += nbits;
 349     if (pms->count[0] < nbits)
 350         pms->count[1]++;
 351
 352     /* Process an initial partial block. */
 353     if (offset) {
 354         unsigned int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
 355
 356         memcpy(pms->buf + offset, p, copy);
 357         if (offset + copy < 64)
 358             return;
 359         p += copy;
 360         left -= copy;
 361         md5_process(pms, pms->buf);
 362     }
 363
 364     /* Process full blocks. */
 365     for (; left >= 64; p += 64, left -= 64)
 366         md5_process(pms, p);
 367
 368     /* Process a final partial block. */
 369     if (left)
 370         memcpy(pms->buf, p, left);
 371 }
 372
 373 void
 374 md5_finish(md5_state_t *pms, md5_byte_t digest[16])
 375 {
 376     static const md5_byte_t pad[64] = {
 377         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 378         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 379         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 380         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 381     };
 382     md5_byte_t data[8];
 383     int i;
 384
 385     /* Save the length before padding. */
 386     for (i = 0; i < 8; ++i)
 387         data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
 388     /* Pad to 56 bytes mod 64. */
 389     md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
 390     /* Append the length. */
 391     md5_append(pms, data, 8);
 392     for (i = 0; i < 16; ++i)
 393         digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
 394 }