src/src/auths/md5.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2009 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #ifndef STAND_ALONE
   9 #include "../exim.h"
  10
  11 /* For stand-alone testing, we need to have the structure defined, and
  12 to be able to do I/O */
  13
  14 #else
  15 #include <stdio.h>
  16 #include "../mytypes.h"
  17 typedef struct md5 {
  18   unsigned int length;
  19   unsigned int abcd[4];
  20   }
  21 md5;
  22 #endif
  23
  24
  25
  26 /*************************************************
  27 *        Start off a new MD5 computation.        *
  28 *************************************************/
  29
  30 /*
  31 Argument:  pointer to md5 storage structure
  32 Returns:   nothing
  33 */
  34
  35 void
  36 md5_start(md5 *base)
  37 {
  38 base->abcd[0] = 0x67452301;
  39 base->abcd[1] = 0xefcdab89;
  40 base->abcd[2] = 0x98badcfe;
  41 base->abcd[3] = 0x10325476;
  42 base->length = 0;
  43 }
  44
  45
  46
  47 /*************************************************
  48 *       Process another 64-byte block            *
  49 *************************************************/
  50
  51 /* This function implements central part of the algorithm which is described
  52 in RFC 1321.
  53
  54 Arguments:
  55   base       pointer to md5 storage structure
  56   text       pointer to next 64 bytes of subject text
  57
  58 Returns:     nothing
  59 */
  60
  61 void
  62 md5_mid(md5 *base, const uschar *text)
  63 {
  64 register unsigned int a = base->abcd[0];
  65 register unsigned int b = base->abcd[1];
  66 register unsigned int c = base->abcd[2];
  67 register unsigned int d = base->abcd[3];
  68 int i;
  69 unsigned int X[16];
  70 base->length += 64;
  71
  72 /* Load the 64 bytes into a set of working integers, treating them as 32-bit
  73 numbers in little-endian order. */
  74
  75 for (i = 0; i < 16; i++)
  76   {
  77   X[i] = (unsigned int)(text[0]) |
  78          ((unsigned int)(text[1]) << 8) |
  79          ((unsigned int)(text[2]) << 16) |
  80          ((unsigned int)(text[3]) << 24);
  81   text += 4;
  82   }
  83
  84 /* For each round of processing there is a function to be applied. We define it
  85 as a macro each time round. */
  86
  87 /***********************************************
  88 *                    Round 1                   *
  89 *            F(X,Y,Z) = XY v not(X) Z          *
  90 * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s) *
  91 ***********************************************/
  92
  93 #define OP(a, b, c, d, k, s, ti) \
  94      a += ((b & c) | (~b & d)) + X[k] + (unsigned int)ti; \
  95      a = b + ((a << s) | (a >> (32 - s)))
  96
  97 OP(a, b, c, d,  0,  7, 0xd76aa478);
  98 OP(d, a, b, c,  1, 12, 0xe8c7b756);
  99 OP(c, d, a, b,  2, 17, 0x242070db);
 100 OP(b, c, d, a,  3, 22, 0xc1bdceee);
 101 OP(a, b, c, d,  4,  7, 0xf57c0faf);
 102 OP(d, a, b, c,  5, 12, 0x4787c62a);
 103 OP(c, d, a, b,  6, 17, 0xa8304613);
 104 OP(b, c, d, a,  7, 22, 0xfd469501);
 105 OP(a, b, c, d,  8,  7, 0x698098d8);
 106 OP(d, a, b, c,  9, 12, 0x8b44f7af);
 107 OP(c, d, a, b, 10, 17, 0xffff5bb1);
 108 OP(b, c, d, a, 11, 22, 0x895cd7be);
 109 OP(a, b, c, d, 12,  7, 0x6b901122);
 110 OP(d, a, b, c, 13, 12, 0xfd987193);
 111 OP(c, d, a, b, 14, 17, 0xa679438e);
 112 OP(b, c, d, a, 15, 22, 0x49b40821);
 113
 114 #undef OP
 115
 116 /***********************************************
 117 *                    Round 2                   *
 118 *            F(X,Y,Z) = XZ v Y not(Z)          *
 119 * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s) *
 120 ***********************************************/
 121
 122 #define OP(a, b, c, d, k, s, ti) \
 123      a += ((b & d) | (c & ~d)) + X[k] + (unsigned int)ti; \
 124      a = b + ((a << s) | (a >> (32 - s)))
 125
 126 OP(a, b, c, d,  1,  5, 0xf61e2562);
 127 OP(d, a, b, c,  6,  9, 0xc040b340);
 128 OP(c, d, a, b, 11, 14, 0x265e5a51);
 129 OP(b, c, d, a,  0, 20, 0xe9b6c7aa);
 130 OP(a, b, c, d,  5,  5, 0xd62f105d);
 131 OP(d, a, b, c, 10,  9, 0x02441453);
 132 OP(c, d, a, b, 15, 14, 0xd8a1e681);
 133 OP(b, c, d, a,  4, 20, 0xe7d3fbc8);
 134 OP(a, b, c, d,  9,  5, 0x21e1cde6);
 135 OP(d, a, b, c, 14,  9, 0xc33707d6);
 136 OP(c, d, a, b,  3, 14, 0xf4d50d87);
 137 OP(b, c, d, a,  8, 20, 0x455a14ed);
 138 OP(a, b, c, d, 13,  5, 0xa9e3e905);
 139 OP(d, a, b, c,  2,  9, 0xfcefa3f8);
 140 OP(c, d, a, b,  7, 14, 0x676f02d9);
 141 OP(b, c, d, a, 12, 20, 0x8d2a4c8a);
 142
 143 #undef OP
 144
 145 /***********************************************
 146 *                    Round 3                   *
 147 *            F(X,Y,Z) = X xor Y xor Z          *
 148 * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s) *
 149 ***********************************************/
 150
 151 #define OP(a, b, c, d, k, s, ti) \
 152      a += (b ^ c ^ d) + X[k] + (unsigned int)ti; \
 153      a = b + ((a << s) | (a >> (32 - s)))
 154
 155 OP(a, b, c, d,  5,  4, 0xfffa3942);
 156 OP(d, a, b, c,  8, 11, 0x8771f681);
 157 OP(c, d, a, b, 11, 16, 0x6d9d6122);
 158 OP(b, c, d, a, 14, 23, 0xfde5380c);
 159 OP(a, b, c, d,  1,  4, 0xa4beea44);
 160 OP(d, a, b, c,  4, 11, 0x4bdecfa9);
 161 OP(c, d, a, b,  7, 16, 0xf6bb4b60);
 162 OP(b, c, d, a, 10, 23, 0xbebfbc70);
 163 OP(a, b, c, d, 13,  4, 0x289b7ec6);
 164 OP(d, a, b, c,  0, 11, 0xeaa127fa);
 165 OP(c, d, a, b,  3, 16, 0xd4ef3085);
 166 OP(b, c, d, a,  6, 23, 0x04881d05);
 167 OP(a, b, c, d,  9,  4, 0xd9d4d039);
 168 OP(d, a, b, c, 12, 11, 0xe6db99e5);
 169 OP(c, d, a, b, 15, 16, 0x1fa27cf8);
 170 OP(b, c, d, a,  2, 23, 0xc4ac5665);
 171
 172 #undef OP
 173
 174 /***********************************************
 175 *                    Round 4                   *
 176 *          F(X,Y,Z) = Y xor (X v not(Z))       *
 177 * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s) *
 178 ***********************************************/
 179
 180 #define OP(a, b, c, d, k, s, ti) \
 181      a += (c ^ (b | ~d)) + X[k] + (unsigned int)ti; \
 182      a = b + ((a << s) | (a >> (32 - s)))
 183
 184 OP(a, b, c, d,  0,  6, 0xf4292244);
 185 OP(d, a, b, c,  7, 10, 0x432aff97);
 186 OP(c, d, a, b, 14, 15, 0xab9423a7);
 187 OP(b, c, d, a,  5, 21, 0xfc93a039);
 188 OP(a, b, c, d, 12,  6, 0x655b59c3);
 189 OP(d, a, b, c,  3, 10, 0x8f0ccc92);
 190 OP(c, d, a, b, 10, 15, 0xffeff47d);
 191 OP(b, c, d, a,  1, 21, 0x85845dd1);
 192 OP(a, b, c, d,  8,  6, 0x6fa87e4f);
 193 OP(d, a, b, c, 15, 10, 0xfe2ce6e0);
 194 OP(c, d, a, b,  6, 15, 0xa3014314);
 195 OP(b, c, d, a, 13, 21, 0x4e0811a1);
 196 OP(a, b, c, d,  4,  6, 0xf7537e82);
 197 OP(d, a, b, c, 11, 10, 0xbd3af235);
 198 OP(c, d, a, b,  2, 15, 0x2ad7d2bb);
 199 OP(b, c, d, a,  9, 21, 0xeb86d391);
 200
 201 #undef OP
 202
 203 /* Add the new values back into the accumulators. */
 204
 205 base->abcd[0] += a;
 206 base->abcd[1] += b;
 207 base->abcd[2] += c;
 208 base->abcd[3] += d;
 209 }
 210
 211
 212
 213
 214 /*************************************************
 215 *     Process the final text string              *
 216 *************************************************/
 217
 218 /* The string may be of any length. It is padded out according to the rules
 219 for computing MD5 digests. The final result is then converted to text form
 220 and returned.
 221
 222 Arguments:
 223   base      pointer to the md5 storage structure
 224   text      pointer to the final text vector
 225   length    length of the final text vector
 226   digest    points to 16 bytes in which to place the result
 227
 228 Returns:    nothing
 229 */
 230
 231 void
 232 md5_end(md5 *base, const uschar *text, int length, uschar *digest)
 233 {
 234 int i;
 235 uschar work[64];
 236
 237 /* Process in chunks of 64 until we have less than 64 bytes left. */
 238
 239 while (length >= 64)
 240   {
 241   md5_mid(base, text);
 242   text += 64;
 243   length -= 64;
 244   }
 245
 246 /* If the remaining string contains more than 55 bytes, we must pad it
 247 out to 64, process it, and then set up the final chunk as 56 bytes of
 248 padding. If it has less than 56 bytes, we pad it out to 56 bytes as the
 249 final chunk. */
 250
 251 memcpy(work, text, length);
 252 work[length] = 0x80;
 253
 254 if (length > 55)
 255   {
 256   memset(work+length+1, 0, 63-length);
 257   md5_mid(base, work);
 258   base->length -= 64;
 259   memset(work, 0, 56);
 260   }
 261 else
 262   {
 263   memset(work+length+1, 0, 55-length);
 264   }
 265
 266 /* The final 8 bytes of the final chunk are a 64-bit representation of the
 267 length of the input string *bits*, before padding, low order word first, and
 268 low order bytes first in each word. This implementation is designed for short
 269 strings, and so operates with a single int counter only. */
 270
 271 length += base->length;   /* Total length in bytes */
 272 length <<= 3;             /* Total length in bits */
 273
 274 work[56] = length         & 0xff;
 275 work[57] = (length >>  8) & 0xff;
 276 work[58] = (length >> 16) & 0xff;
 277 work[59] = (length >> 24) & 0xff;
 278
 279 memset(work+60, 0, 4);
 280
 281 /* Process the final 64-byte chunk */
 282
 283 md5_mid(base, work);
 284
 285 /* Pass back the result, low-order byte first in each word. */
 286
 287 for (i = 0; i < 4; i++)
 288   {
 289   register int x = base->abcd[i];
 290   *digest++ =  x        & 0xff;
 291   *digest++ = (x >>  8) & 0xff;
 292   *digest++ = (x >> 16) & 0xff;
 293   *digest++ = (x >> 24) & 0xff;
 294   }
 295 }
 296
 297
 298
 299 /*************************************************
 300 **************************************************
 301 *             Stand-alone test program           *
 302 **************************************************
 303 *************************************************/
 304
 305 #if defined STAND_ALONE & !defined CRAM_STAND_ALONE
 306
 307 /* Test values */
 308
 309 static uschar *tests[] = {
 310   "", "d41d8cd98f00b204e9800998ecf8427e",
 311
 312   "a", "0cc175b9c0f1b6a831c399e269772661",
 313
 314   "abc", "900150983cd24fb0d6963f7d28e17f72",
 315
 316   "message digest", "f96b697d7cb7938d525a2f31aaf161d0",
 317
 318   "abcdefghijklmnopqrstuvwxyz", "c3fcd3d76192e4007dfb496cca67e13b",
 319
 320   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
 321      "d174ab98d277d9f5a5611c2c9f419d9f",
 322
 323   "1234567890123456789012345678901234567890123456789012345678901234567890"
 324   "1234567890",
 325     "57edf4a22be3c955ac49da2e2107b67a",
 326
 327   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
 328   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
 329   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
 330     "a0842fcc02167127b0bb9a7c38e71ba8"
 331 };
 332
 333 int main(void)
 334 {
 335 md5 base;
 336 int i = 0x01020304;
 337 uschar *ctest = (uschar *)(&i);
 338 uschar buffer[256];
 339 uschar digest[16];
 340 printf("Checking md5: %s-endian\n", (ctest[0] == 0x04)? "little" : "big");
 341
 342 for (i = 0; i < sizeof(tests)/sizeof(uschar *); i += 2)
 343   {
 344   int j;
 345   uschar s[33];
 346   printf("%s\nShould be: %s\n", tests[i], tests[i+1]);
 347   md5_start(&base);
 348   md5_end(&base, tests[i], strlen(tests[i]), digest);
 349   for (j = 0; j < 16; j++) sprintf(s+2*j, "%02x", digest[j]);
 350   printf("Computed:  %s\n", s);
 351   if (strcmp(s, tests[i+1]) != 0) printf("*** No match ***\n");
 352   printf("\n");
 353   }
 354 }
 355 #endif
 356
 357 /* End of md5.c */