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dbus-md5.c

00001 /* -*- mode: C; c-file-style: "gnu" -*- */
00002 /* dbus-md5.c md5 implementation (based on L Peter Deutsch implementation)
00003  *
00004  * Copyright (C) 2003 Red Hat Inc.
00005  * Copyright (C) 1999, 2000 Aladdin Enterprises.  All rights reserved.
00006  *
00007  * This software is provided 'as-is', without any express or implied
00008  * warranty.  In no event will the authors be held liable for any damages
00009  * arising from the use of this software.
00010  *
00011  * Permission is granted to anyone to use this software for any purpose,
00012  * including commercial applications, and to alter it and redistribute it
00013  * freely, subject to the following restrictions:
00014  *
00015  * 1. The origin of this software must not be misrepresented; you must not
00016  *    claim that you wrote the original software. If you use this software
00017  *    in a product, an acknowledgment in the product documentation would be
00018  *    appreciated but is not required.
00019  * 2. Altered source versions must be plainly marked as such, and must not be
00020  *    misrepresented as being the original software.
00021  * 3. This notice may not be removed or altered from any source distribution.
00022  *
00023  * L. Peter Deutsch
00024  * ghost@aladdin.com
00025  */
00026 /*
00027  * Independent implementation of MD5 (RFC 1321).
00028  *
00029  * This code implements the MD5 Algorithm defined in RFC 1321.
00030  * It is derived directly from the text of the RFC and not from the
00031  * reference implementation.
00032  *
00033  * The original and principal author of md5.c is L. Peter Deutsch
00034  * <ghost@aladdin.com>.
00035  */
00036 
00037 #include "dbus-internals.h"
00038 #include "dbus-md5.h"
00039 #include <string.h>
00040 
00062 #ifndef DOXYGEN_SHOULD_SKIP_THIS
00063 /*
00064  * For reference, here is the program that computed the T values.
00065  */
00066 #ifdef COMPUTE_T_VALUES
00067 #include <math.h>
00068 int
00069 main(int argc, char **argv)
00070 {
00071   int i;
00072   for (i = 1; i <= 64; ++i)
00073     {
00074       unsigned long v = (unsigned long)(4294967296.0 * fabs(sin((double)i)));
00075 
00076       /*
00077        * The following nonsense is only to avoid compiler warnings about
00078        * "integer constant is unsigned in ANSI C, signed with -traditional".
00079        */
00080       if (v >> 31)
00081         {
00082           printf("#define T%d /* 0x%08lx */ (T_MASK ^ 0x%08lx)\n", i,
00083                  v, (unsigned long)(unsigned int)(~v));
00084         } else {
00085         printf("#define T%d    0x%08lx\n", i, v);
00086       }
00087     }
00088   return 0;
00089 }
00090 #endif /* COMPUTE_T_VALUES */
00091 /*
00092  * End of T computation program.
00093  */
00094 
00095 #define T_MASK ((dbus_uint32_t)~0)
00096 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
00097 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
00098 #define T3    0x242070db
00099 #define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
00100 #define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
00101 #define T6    0x4787c62a
00102 #define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
00103 #define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
00104 #define T9    0x698098d8
00105 #define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
00106 #define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
00107 #define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
00108 #define T13    0x6b901122
00109 #define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
00110 #define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
00111 #define T16    0x49b40821
00112 #define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
00113 #define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
00114 #define T19    0x265e5a51
00115 #define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
00116 #define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
00117 #define T22    0x02441453
00118 #define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
00119 #define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
00120 #define T25    0x21e1cde6
00121 #define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
00122 #define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
00123 #define T28    0x455a14ed
00124 #define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
00125 #define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
00126 #define T31    0x676f02d9
00127 #define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
00128 #define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
00129 #define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
00130 #define T35    0x6d9d6122
00131 #define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
00132 #define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
00133 #define T38    0x4bdecfa9
00134 #define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
00135 #define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
00136 #define T41    0x289b7ec6
00137 #define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
00138 #define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
00139 #define T44    0x04881d05
00140 #define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
00141 #define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
00142 #define T47    0x1fa27cf8
00143 #define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
00144 #define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
00145 #define T50    0x432aff97
00146 #define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
00147 #define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
00148 #define T53    0x655b59c3
00149 #define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
00150 #define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
00151 #define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
00152 #define T57    0x6fa87e4f
00153 #define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
00154 #define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
00155 #define T60    0x4e0811a1
00156 #define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
00157 #define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
00158 #define T63    0x2ad7d2bb
00159 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
00160 #endif /* DOXYGEN_SHOULD_SKIP_THIS */
00161 
00162 static void
00163 md5_process(DBusMD5Context *context, const unsigned char *data /*[64]*/)
00164 {
00165   dbus_uint32_t
00166     a = context->abcd[0], b = context->abcd[1],
00167     c = context->abcd[2], d = context->abcd[3];
00168   dbus_uint32_t t;
00169 
00170 #ifdef WORDS_BIGENDIAN
00171   /*
00172    * On big-endian machines, we must arrange the bytes in the right
00173    * order.  (This also works on machines of unknown byte order.)
00174    */
00175   dbus_uint32_t X[16];
00176   const unsigned char *xp = data;
00177   int i;
00178 
00179   for (i = 0; i < 16; ++i, xp += 4)
00180     X[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
00181 
00182 #else  /* !WORDS_BIGENDIAN */
00183   /*
00184    * On little-endian machines, we can process properly aligned data
00185    * without copying it.
00186    */
00187   dbus_uint32_t xbuf[16];
00188   const dbus_uint32_t *X;
00189 
00190   if (!((data - (const unsigned char *)0) & 3))
00191     {
00192       /* data are properly aligned */
00193       X = (const dbus_uint32_t *)data;
00194     }
00195   else
00196     {
00197       /* not aligned */
00198       memcpy(xbuf, data, 64);
00199       X = xbuf;
00200     }
00201 #endif
00202 
00203 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
00204 
00205   /* Round 1. */
00206   /* Let [abcd k s i] denote the operation
00207      a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
00208 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
00209 #define SET(a, b, c, d, k, s, Ti)               \
00210   t = a + F(b,c,d) + X[k] + Ti;                 \
00211   a = ROTATE_LEFT(t, s) + b
00212   /* Do the following 16 operations. */
00213   SET(a, b, c, d,  0,  7,  T1);
00214   SET(d, a, b, c,  1, 12,  T2);
00215   SET(c, d, a, b,  2, 17,  T3);
00216   SET(b, c, d, a,  3, 22,  T4);
00217   SET(a, b, c, d,  4,  7,  T5);
00218   SET(d, a, b, c,  5, 12,  T6);
00219   SET(c, d, a, b,  6, 17,  T7);
00220   SET(b, c, d, a,  7, 22,  T8);
00221   SET(a, b, c, d,  8,  7,  T9);
00222   SET(d, a, b, c,  9, 12, T10);
00223   SET(c, d, a, b, 10, 17, T11);
00224   SET(b, c, d, a, 11, 22, T12);
00225   SET(a, b, c, d, 12,  7, T13);
00226   SET(d, a, b, c, 13, 12, T14);
00227   SET(c, d, a, b, 14, 17, T15);
00228   SET(b, c, d, a, 15, 22, T16);
00229 #undef SET
00230 
00231   /* Round 2. */
00232   /* Let [abcd k s i] denote the operation
00233      a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
00234 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
00235 #define SET(a, b, c, d, k, s, Ti)               \
00236   t = a + G(b,c,d) + X[k] + Ti;                 \
00237   a = ROTATE_LEFT(t, s) + b
00238   /* Do the following 16 operations. */
00239   SET(a, b, c, d,  1,  5, T17);
00240   SET(d, a, b, c,  6,  9, T18);
00241   SET(c, d, a, b, 11, 14, T19);
00242   SET(b, c, d, a,  0, 20, T20);
00243   SET(a, b, c, d,  5,  5, T21);
00244   SET(d, a, b, c, 10,  9, T22);
00245   SET(c, d, a, b, 15, 14, T23);
00246   SET(b, c, d, a,  4, 20, T24);
00247   SET(a, b, c, d,  9,  5, T25);
00248   SET(d, a, b, c, 14,  9, T26);
00249   SET(c, d, a, b,  3, 14, T27);
00250   SET(b, c, d, a,  8, 20, T28);
00251   SET(a, b, c, d, 13,  5, T29);
00252   SET(d, a, b, c,  2,  9, T30);
00253   SET(c, d, a, b,  7, 14, T31);
00254   SET(b, c, d, a, 12, 20, T32);
00255 #undef SET
00256 
00257   /* Round 3. */
00258   /* Let [abcd k s t] denote the operation
00259      a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
00260 #define H(x, y, z) ((x) ^ (y) ^ (z))
00261 #define SET(a, b, c, d, k, s, Ti)               \
00262   t = a + H(b,c,d) + X[k] + Ti;                 \
00263   a = ROTATE_LEFT(t, s) + b
00264   /* Do the following 16 operations. */
00265   SET(a, b, c, d,  5,  4, T33);
00266   SET(d, a, b, c,  8, 11, T34);
00267   SET(c, d, a, b, 11, 16, T35);
00268   SET(b, c, d, a, 14, 23, T36);
00269   SET(a, b, c, d,  1,  4, T37);
00270   SET(d, a, b, c,  4, 11, T38);
00271   SET(c, d, a, b,  7, 16, T39);
00272   SET(b, c, d, a, 10, 23, T40);
00273   SET(a, b, c, d, 13,  4, T41);
00274   SET(d, a, b, c,  0, 11, T42);
00275   SET(c, d, a, b,  3, 16, T43);
00276   SET(b, c, d, a,  6, 23, T44);
00277   SET(a, b, c, d,  9,  4, T45);
00278   SET(d, a, b, c, 12, 11, T46);
00279   SET(c, d, a, b, 15, 16, T47);
00280   SET(b, c, d, a,  2, 23, T48);
00281 #undef SET
00282 
00283   /* Round 4. */
00284   /* Let [abcd k s t] denote the operation
00285      a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
00286 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
00287 #define SET(a, b, c, d, k, s, Ti)               \
00288   t = a + I(b,c,d) + X[k] + Ti;                 \
00289   a = ROTATE_LEFT(t, s) + b
00290   /* Do the following 16 operations. */
00291   SET(a, b, c, d,  0,  6, T49);
00292   SET(d, a, b, c,  7, 10, T50);
00293   SET(c, d, a, b, 14, 15, T51);
00294   SET(b, c, d, a,  5, 21, T52);
00295   SET(a, b, c, d, 12,  6, T53);
00296   SET(d, a, b, c,  3, 10, T54);
00297   SET(c, d, a, b, 10, 15, T55);
00298   SET(b, c, d, a,  1, 21, T56);
00299   SET(a, b, c, d,  8,  6, T57);
00300   SET(d, a, b, c, 15, 10, T58);
00301   SET(c, d, a, b,  6, 15, T59);
00302   SET(b, c, d, a, 13, 21, T60);
00303   SET(a, b, c, d,  4,  6, T61);
00304   SET(d, a, b, c, 11, 10, T62);
00305   SET(c, d, a, b,  2, 15, T63);
00306   SET(b, c, d, a,  9, 21, T64);
00307 #undef SET
00308 
00309   /* Then perform the following additions. (That is increment each
00310      of the four registers by the value it had before this block
00311      was started.) */
00312   context->abcd[0] += a;
00313   context->abcd[1] += b;
00314   context->abcd[2] += c;
00315   context->abcd[3] += d;
00316 }
00317 
00318 static void
00319 md5_init (DBusMD5Context *context)
00320 {
00321   context->count[0] = context->count[1] = 0;
00322   context->abcd[0] = 0x67452301;
00323   context->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
00324   context->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
00325   context->abcd[3] = 0x10325476;
00326 }
00327 
00328 static void
00329 md5_append (DBusMD5Context *context, const unsigned char *data, int nbytes)
00330 {
00331   const unsigned char *p = data;
00332   int left = nbytes;
00333   int offset = (context->count[0] >> 3) & 63;
00334   dbus_uint32_t nbits = (dbus_uint32_t)(nbytes << 3);
00335 
00336   if (nbytes <= 0)
00337     return;
00338 
00339   /* Update the message length. */
00340   context->count[1] += nbytes >> 29;
00341   context->count[0] += nbits;
00342   if (context->count[0] < nbits)
00343     context->count[1]++;
00344 
00345   /* Process an initial partial block. */
00346   if (offset)
00347     {
00348       int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
00349 
00350       memcpy(context->buf + offset, p, copy);
00351       if (offset + copy < 64)
00352         return;
00353       p += copy;
00354       left -= copy;
00355       md5_process(context, context->buf);
00356     }
00357 
00358   /* Process full blocks. */
00359   for (; left >= 64; p += 64, left -= 64)
00360     md5_process(context, p);
00361 
00362   /* Process a final partial block. */
00363   if (left)
00364     memcpy(context->buf, p, left);
00365 }
00366 
00367 static void
00368 md5_finish (DBusMD5Context *context, unsigned char digest[16])
00369 {
00370   static const unsigned char pad[64] = {
00371     0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
00372     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
00373     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
00374     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
00375   };
00376   unsigned char data[8];
00377   int i;
00378 
00379   /* Save the length before padding. */
00380   for (i = 0; i < 8; ++i)
00381     data[i] = (unsigned char)(context->count[i >> 2] >> ((i & 3) << 3));
00382   /* Pad to 56 bytes mod 64. */
00383   md5_append(context, pad, ((55 - (context->count[0] >> 3)) & 63) + 1);
00384   /* Append the length. */
00385   md5_append(context, data, 8);
00386   for (i = 0; i < 16; ++i)
00387     digest[i] = (unsigned char)(context->abcd[i >> 2] >> ((i & 3) << 3));
00388 }
00389  /* End of internals */
00391 
00403 void
00404 _dbus_md5_init (DBusMD5Context *context)
00405 {
00406   md5_init (context);
00407 }
00408 
00409 
00416 void
00417 _dbus_md5_update (DBusMD5Context   *context,
00418                   const DBusString *data)
00419 {
00420   unsigned int inputLen;
00421   unsigned char *input;
00422 
00423   _dbus_string_get_const_data (data, (const char**) &input);
00424   inputLen = _dbus_string_get_length (data);
00425 
00426   md5_append (context, input, inputLen);
00427 }
00428 
00440 dbus_bool_t
00441 _dbus_md5_final (DBusMD5Context   *context,
00442                  DBusString       *results)
00443 {
00444   unsigned char digest[16];
00445 
00446   md5_finish (context, digest);
00447 
00448   if (!_dbus_string_append_len (results, digest, 16))
00449     return FALSE;
00450 
00451   /* some kind of security paranoia, though it seems pointless
00452    * to me given the nonzeroed stuff flying around
00453    */
00454   memset ((void*)context, '\0', sizeof (DBusMD5Context));
00455 
00456   return TRUE;
00457 }
00458 
00467 dbus_bool_t
00468 _dbus_md5_compute (const DBusString *data,
00469                    DBusString       *ascii_output)
00470 {
00471   DBusMD5Context context;
00472   DBusString digest;
00473 
00474   _dbus_md5_init (&context);
00475 
00476   _dbus_md5_update (&context, data);
00477 
00478   if (!_dbus_string_init (&digest))
00479     return FALSE;
00480 
00481   if (!_dbus_md5_final (&context, &digest))
00482     goto error;
00483 
00484   if (!_dbus_string_hex_encode (&digest, 0, ascii_output,
00485                                 _dbus_string_get_length (ascii_output)))
00486     goto error;
00487 
00488   _dbus_string_free (&digest);
00489   
00490   return TRUE;
00491 
00492  error:
00493   _dbus_string_free (&digest);
00494   return FALSE;
00495 }
00496  /* end of exported functions */
00498 
00499 #ifdef DBUS_BUILD_TESTS
00500 #include "dbus-test.h"
00501 #include <stdio.h>
00502 
00503 static dbus_bool_t
00504 check_md5_binary (const unsigned char *input,
00505                   int                  input_len,
00506                   const char          *expected)
00507 {
00508   DBusString input_str;
00509   DBusString expected_str;
00510   DBusString results;
00511 
00512   _dbus_string_init_const_len (&input_str, input, input_len);
00513   _dbus_string_init_const (&expected_str, expected);
00514 
00515   if (!_dbus_string_init (&results))
00516     _dbus_assert_not_reached ("no memory for md5 results");
00517 
00518   if (!_dbus_md5_compute (&input_str, &results))
00519     _dbus_assert_not_reached ("no memory for md5 results");
00520 
00521   if (!_dbus_string_equal (&expected_str, &results))
00522     {
00523       const char *s;
00524       _dbus_string_get_const_data (&results, &s);
00525       _dbus_warn ("Expected hash %s got %s for md5 sum\n",
00526                   expected, s);
00527       _dbus_string_free (&results);
00528       return FALSE;
00529     }
00530 
00531   _dbus_string_free (&results);
00532   return TRUE;
00533 }
00534 
00535 static dbus_bool_t
00536 check_md5_str (const char *input,
00537                const char *expected)
00538 {
00539   return check_md5_binary (input, strlen (input), expected);
00540 }
00541 
00548 dbus_bool_t
00549 _dbus_md5_test (void)
00550 {
00551   unsigned char all_bytes[256];
00552   int i;
00553 
00554   i = 0;
00555   while (i < 256)
00556     {
00557       all_bytes[i] = i;
00558       ++i;
00559     }
00560 
00561   if (!check_md5_binary (all_bytes, 256,
00562                          "e2c865db4162bed963bfaa9ef6ac18f0"))
00563     return FALSE;
00564 
00565 #define CHECK(input,expected) if (!check_md5_str (input, expected)) return FALSE
00566 
00567   CHECK ("", "d41d8cd98f00b204e9800998ecf8427e");
00568   CHECK ("a", "0cc175b9c0f1b6a831c399e269772661");
00569   CHECK ("abc", "900150983cd24fb0d6963f7d28e17f72");
00570   CHECK ("message digest", "f96b697d7cb7938d525a2f31aaf161d0");
00571   CHECK ("abcdefghijklmnopqrstuvwxyz", "c3fcd3d76192e4007dfb496cca67e13b");
00572   CHECK ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
00573          "d174ab98d277d9f5a5611c2c9f419d9f");
00574   CHECK ("12345678901234567890123456789012345678901234567890123456789012345678901234567890",
00575          "57edf4a22be3c955ac49da2e2107b67a");
00576 
00577   return TRUE;
00578 }
00579 
00580 #endif /* DBUS_BUILD_TESTS */

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