/Modules/md5.c

http://unladen-swallow.googlecode.com/ · C · 394 lines · 270 code · 27 blank · 97 comment · 17 complexity · cde8744da846bbcd348a5126acb9f7b0 MD5 · raw file

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