lib/md5.c

   1 /*
   2   arch-tag: md5 implementation
   3
   4   Copyright (C) 1999, 2000, 2002 Aladdin Enterprises.  All rights reserved.
   5
   6   This software is provided 'as-is', without any express or implied
   7   warranty.  In no event will the authors be held liable for any damages
   8   arising from the use of this software.
   9
  10   Permission is granted to anyone to use this software for any purpose,
  11   including commercial applications, and to alter it and redistribute it
  12   freely, subject to the following restrictions:
  13
  14   1. The origin of this software must not be misrepresented; you must not
  15      claim that you wrote the original software. If you use this software
  16      in a product, an acknowledgment in the product documentation would be
  17      appreciated but is not required.
  18   2. Altered source versions must be plainly marked as such, and must not be
  19      misrepresented as being the original software.
  20   3. This notice may not be removed or altered from any source distribution.
  21
  22   L. Peter Deutsch
  23   ghost@aladdin.com
  24
  25  */
  26 /* $Id: md5.c,v 1.1 2005/10/21 02:27:17 rps Exp $ */
  27 /*
  28   Independent implementation of MD5 (RFC 1321).
  29
  30   This code implements the MD5 Algorithm defined in RFC 1321, whose
  31   text is available at
  32         http://www.ietf.org/rfc/rfc1321.txt
  33   The code is derived from the text of the RFC, including the test suite
  34   (section A.5) but excluding the rest of Appendix A.  It does not include
  35   any code or documentation that is identified in the RFC as being
  36   copyrighted.
  37
  38   The original and principal author of md5.c is L. Peter Deutsch
  39   <ghost@aladdin.com>.  Other authors are noted in the change history
  40   that follows (in reverse chronological order):
  41
  42   2002-04-13 lpd Clarified derivation from RFC 1321; now handles byte order
  43         either statically or dynamically; added missing #include <string.h>
  44         in library.
  45   2002-03-11 lpd Corrected argument list for main(), and added int return
  46         type, in test program and T value program.
  47   2002-02-21 lpd Added missing #include <stdio.h> in test program.
  48   2000-07-03 lpd Patched to eliminate warnings about "constant is
  49         unsigned in ANSI C, signed in traditional"; made test program
  50         self-checking.
  51   1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
  52   1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5).
  53   1999-05-03 lpd Original version.
  54  */
  55
  56 #include "md5.h"
  57 #include <string.h>
  58
  59 #undef BYTE_ORDER       /* 1 = big-endian, -1 = little-endian, 0 = unknown */
  60 #ifdef ARCH_IS_BIG_ENDIAN
  61 #  define BYTE_ORDER (ARCH_IS_BIG_ENDIAN ? 1 : -1)
  62 #else
  63 #  define BYTE_ORDER 0
  64 #endif
  65
  66 #define T_MASK ((md5_word_t)~0)
  67 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
  68 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
  69 #define T3    0x242070db
  70 #define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
  71 #define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
  72 #define T6    0x4787c62a
  73 #define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
  74 #define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
  75 #define T9    0x698098d8
  76 #define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
  77 #define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
  78 #define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
  79 #define T13    0x6b901122
  80 #define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
  81 #define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
  82 #define T16    0x49b40821
  83 #define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
  84 #define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
  85 #define T19    0x265e5a51
  86 #define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
  87 #define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
  88 #define T22    0x02441453
  89 #define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
  90 #define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
  91 #define T25    0x21e1cde6
  92 #define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
  93 #define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
  94 #define T28    0x455a14ed
  95 #define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
  96 #define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
  97 #define T31    0x676f02d9
  98 #define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
  99 #define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
 100 #define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
 101 #define T35    0x6d9d6122
 102 #define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
 103 #define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
 104 #define T38    0x4bdecfa9
 105 #define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
 106 #define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
 107 #define T41    0x289b7ec6
 108 #define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
 109 #define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
 110 #define T44    0x04881d05
 111 #define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
 112 #define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
 113 #define T47    0x1fa27cf8
 114 #define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
 115 #define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
 116 #define T50    0x432aff97
 117 #define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
 118 #define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
 119 #define T53    0x655b59c3
 120 #define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
 121 #define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
 122 #define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
 123 #define T57    0x6fa87e4f
 124 #define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
 125 #define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
 126 #define T60    0x4e0811a1
 127 #define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
 128 #define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
 129 #define T63    0x2ad7d2bb
 130 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
 131
 132
 133 static void
 134 md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/)
 135 {
 136     md5_word_t
 137         a = pms->abcd[0], b = pms->abcd[1],
 138         c = pms->abcd[2], d = pms->abcd[3];
 139     md5_word_t t;
 140 #if BYTE_ORDER > 0
 141     /* Define storage only for big-endian CPUs. */
 142     md5_word_t X[16];
 143 #else
 144     /* Define storage for little-endian or both types of CPUs. */
 145     md5_word_t xbuf[16];
 146     const md5_word_t *X;
 147 #endif
 148
 149     {
 150 #if BYTE_ORDER == 0
 151         /*
 152          * Determine dynamically whether this is a big-endian or
 153          * little-endian machine, since we can use a more efficient
 154          * algorithm on the latter.
 155          */
 156         static const int w = 1;
 157
 158         if (*((const md5_byte_t *)&w)) /* dynamic little-endian */
 159 #endif
 160 #if BYTE_ORDER <= 0             /* little-endian */
 161         {
 162             /*
 163              * On little-endian machines, we can process properly aligned
 164              * data without copying it.
 165              */
 166             if (!((data - (const md5_byte_t *)0) & 3)) {
 167                 /* data are properly aligned */
 168                 X = (const md5_word_t *)data;
 169             } else {
 170                 /* not aligned */
 171                 memcpy(xbuf, data, 64);
 172                 X = xbuf;
 173             }
 174         }
 175 #endif
 176 #if BYTE_ORDER == 0
 177         else                    /* dynamic big-endian */
 178 #endif
 179 #if BYTE_ORDER >= 0             /* big-endian */
 180         {
 181             /*
 182              * On big-endian machines, we must arrange the bytes in the
 183              * right order.
 184              */
 185             const md5_byte_t *xp = data;
 186             int i;
 187
 188 #  if BYTE_ORDER == 0
 189             X = xbuf;           /* (dynamic only) */
 190 #  else
 191 #    define xbuf X              /* (static only) */
 192 #  endif
 193             for (i = 0; i < 16; ++i, xp += 4)
 194                 xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
 195         }
 196 #endif
 197     }
 198
 199 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
 200
 201     /* Round 1. */
 202     /* Let [abcd k s i] denote the operation
 203        a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
 204 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
 205 #define SET(a, b, c, d, k, s, Ti)\
 206   t = a + F(b,c,d) + X[k] + Ti;\
 207   a = ROTATE_LEFT(t, s) + b
 208     /* Do the following 16 operations. */
 209     SET(a, b, c, d,  0,  7,  T1);
 210     SET(d, a, b, c,  1, 12,  T2);
 211     SET(c, d, a, b,  2, 17,  T3);
 212     SET(b, c, d, a,  3, 22,  T4);
 213     SET(a, b, c, d,  4,  7,  T5);
 214     SET(d, a, b, c,  5, 12,  T6);
 215     SET(c, d, a, b,  6, 17,  T7);
 216     SET(b, c, d, a,  7, 22,  T8);
 217     SET(a, b, c, d,  8,  7,  T9);
 218     SET(d, a, b, c,  9, 12, T10);
 219     SET(c, d, a, b, 10, 17, T11);
 220     SET(b, c, d, a, 11, 22, T12);
 221     SET(a, b, c, d, 12,  7, T13);
 222     SET(d, a, b, c, 13, 12, T14);
 223     SET(c, d, a, b, 14, 17, T15);
 224     SET(b, c, d, a, 15, 22, T16);
 225 #undef SET
 226
 227      /* Round 2. */
 228      /* Let [abcd k s i] denote the operation
 229           a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
 230 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
 231 #define SET(a, b, c, d, k, s, Ti)\
 232   t = a + G(b,c,d) + X[k] + Ti;\
 233   a = ROTATE_LEFT(t, s) + b
 234      /* Do the following 16 operations. */
 235     SET(a, b, c, d,  1,  5, T17);
 236     SET(d, a, b, c,  6,  9, T18);
 237     SET(c, d, a, b, 11, 14, T19);
 238     SET(b, c, d, a,  0, 20, T20);
 239     SET(a, b, c, d,  5,  5, T21);
 240     SET(d, a, b, c, 10,  9, T22);
 241     SET(c, d, a, b, 15, 14, T23);
 242     SET(b, c, d, a,  4, 20, T24);
 243     SET(a, b, c, d,  9,  5, T25);
 244     SET(d, a, b, c, 14,  9, T26);
 245     SET(c, d, a, b,  3, 14, T27);
 246     SET(b, c, d, a,  8, 20, T28);
 247     SET(a, b, c, d, 13,  5, T29);
 248     SET(d, a, b, c,  2,  9, T30);
 249     SET(c, d, a, b,  7, 14, T31);
 250     SET(b, c, d, a, 12, 20, T32);
 251 #undef SET
 252
 253      /* Round 3. */
 254      /* Let [abcd k s t] denote the operation
 255           a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
 256 #define H(x, y, z) ((x) ^ (y) ^ (z))
 257 #define SET(a, b, c, d, k, s, Ti)\
 258   t = a + H(b,c,d) + X[k] + Ti;\
 259   a = ROTATE_LEFT(t, s) + b
 260      /* Do the following 16 operations. */
 261     SET(a, b, c, d,  5,  4, T33);
 262     SET(d, a, b, c,  8, 11, T34);
 263     SET(c, d, a, b, 11, 16, T35);
 264     SET(b, c, d, a, 14, 23, T36);
 265     SET(a, b, c, d,  1,  4, T37);
 266     SET(d, a, b, c,  4, 11, T38);
 267     SET(c, d, a, b,  7, 16, T39);
 268     SET(b, c, d, a, 10, 23, T40);
 269     SET(a, b, c, d, 13,  4, T41);
 270     SET(d, a, b, c,  0, 11, T42);
 271     SET(c, d, a, b,  3, 16, T43);
 272     SET(b, c, d, a,  6, 23, T44);
 273     SET(a, b, c, d,  9,  4, T45);
 274     SET(d, a, b, c, 12, 11, T46);
 275     SET(c, d, a, b, 15, 16, T47);
 276     SET(b, c, d, a,  2, 23, T48);
 277 #undef SET
 278
 279      /* Round 4. */
 280      /* Let [abcd k s t] denote the operation
 281           a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
 282 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
 283 #define SET(a, b, c, d, k, s, Ti)\
 284   t = a + I(b,c,d) + X[k] + Ti;\
 285   a = ROTATE_LEFT(t, s) + b
 286      /* Do the following 16 operations. */
 287     SET(a, b, c, d,  0,  6, T49);
 288     SET(d, a, b, c,  7, 10, T50);
 289     SET(c, d, a, b, 14, 15, T51);
 290     SET(b, c, d, a,  5, 21, T52);
 291     SET(a, b, c, d, 12,  6, T53);
 292     SET(d, a, b, c,  3, 10, T54);
 293     SET(c, d, a, b, 10, 15, T55);
 294     SET(b, c, d, a,  1, 21, T56);
 295     SET(a, b, c, d,  8,  6, T57);
 296     SET(d, a, b, c, 15, 10, T58);
 297     SET(c, d, a, b,  6, 15, T59);
 298     SET(b, c, d, a, 13, 21, T60);
 299     SET(a, b, c, d,  4,  6, T61);
 300     SET(d, a, b, c, 11, 10, T62);
 301     SET(c, d, a, b,  2, 15, T63);
 302     SET(b, c, d, a,  9, 21, T64);
 303 #undef SET
 304
 305      /* Then perform the following additions. (That is increment each
 306         of the four registers by the value it had before this block
 307         was started.) */
 308     pms->abcd[0] += a;
 309     pms->abcd[1] += b;
 310     pms->abcd[2] += c;
 311     pms->abcd[3] += d;
 312 }
 313
 314 void
 315 md5_init(md5_state_t *pms)
 316 {
 317     pms->count[0] = pms->count[1] = 0;
 318     pms->abcd[0] = 0x67452301;
 319     pms->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
 320     pms->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
 321     pms->abcd[3] = 0x10325476;
 322 }
 323
 324 void
 325 md5_append(md5_state_t *pms, const md5_byte_t *data, int nbytes)
 326 {
 327     const md5_byte_t *p = data;
 328     int left = nbytes;
 329     int offset = (pms->count[0] >> 3) & 63;
 330     md5_word_t nbits = (md5_word_t)(nbytes << 3);
 331
 332     if (nbytes <= 0)
 333         return;
 334
 335     /* Update the message length. */
 336     pms->count[1] += nbytes >> 29;
 337     pms->count[0] += nbits;
 338     if (pms->count[0] < nbits)
 339         pms->count[1]++;
 340
 341     /* Process an initial partial block. */
 342     if (offset) {
 343         int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
 344
 345         memcpy(pms->buf + offset, p, copy);
 346         if (offset + copy < 64)
 347             return;
 348         p += copy;
 349         left -= copy;
 350         md5_process(pms, pms->buf);
 351     }
 352
 353     /* Process full blocks. */
 354     for (; left >= 64; p += 64, left -= 64)
 355         md5_process(pms, p);
 356
 357     /* Process a final partial block. */
 358     if (left)
 359         memcpy(pms->buf, p, left);
 360 }
 361
 362 void
 363 md5_finish(md5_state_t *pms, md5_byte_t digest[16])
 364 {
 365     static const md5_byte_t pad[64] = {
 366         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 367         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 368         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 369         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 370     };
 371     md5_byte_t data[8];
 372     int i;
 373
 374     /* Save the length before padding. */
 375     for (i = 0; i < 8; ++i)
 376         data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
 377     /* Pad to 56 bytes mod 64. */
 378     md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
 379     /* Append the length. */
 380     md5_append(pms, data, 8);
 381     for (i = 0; i < 16; ++i)
 382         digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
 383 }