src/misc/md5.c

   1 /*****************************************************************************
   2  * md5.c: not so strong MD5 hashing
   3  *****************************************************************************
   4  * Copyright (C) 1995,1996,1998,1999,2001,2002,
   5  *               2003  Free Software Foundation, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  20  *****************************************************************************/
  21
  22 /* md5.c - MD5 Message-Digest Algorithm
  23  *
  24  * According to the definition of MD5 in RFC 1321 from April 1992.
  25  * NOTE: This is *not* the same file as the one from glibc.
  26  * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
  27  * heavily modified for GnuPG by Werner Koch <wk@gnupg.org>
  28  */
  29
  30 /* Test values:
  31  * ""                  D4 1D 8C D9 8F 00 B2 04  E9 80 09 98 EC F8 42 7E
  32  * "a"                 0C C1 75 B9 C0 F1 B6 A8  31 C3 99 E2 69 77 26 61
  33  * "abc                90 01 50 98 3C D2 4F B0  D6 96 3F 7D 28 E1 7F 72
  34  * "message digest"    F9 6B 69 7D 7C B7 93 8D  52 5A 2F 31 AA F1 61 D0
  35  */
  36
  37 #ifdef HAVE_CONFIG_H
  38 # include "config.h"
  39 #endif
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43
  44 #include <vlc_common.h>
  45 #include <vlc_md5.h>
  46
  47 typedef uint32_t u32;
  48 typedef uint8_t byte;
  49 #define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
  50
  51 typedef struct md5_s MD5_CONTEXT;
  52
  53
  54 static void
  55 md5_init( void *context )
  56 {
  57   MD5_CONTEXT *ctx = context;
  58
  59   ctx->A = 0x67452301;
  60   ctx->B = 0xefcdab89;
  61   ctx->C = 0x98badcfe;
  62   ctx->D = 0x10325476;
  63
  64   ctx->nblocks = 0;
  65   ctx->count = 0;
  66 }
  67
  68
  69 /* These are the four functions used in the four steps of the MD5 algorithm
  70    and defined in the RFC 1321.  The first function is a little bit optimized
  71    (as found in Colin Plumbs public domain implementation).  */
  72 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
  73 #define FF(b, c, d) (d ^ (b & (c ^ d)))
  74 #define FG(b, c, d) FF (d, b, c)
  75 #define FH(b, c, d) (b ^ c ^ d)
  76 #define FI(b, c, d) (c ^ (b | ~d))
  77
  78
  79 /****************
  80  * transform n*64 bytes
  81  */
  82 static void
  83 transform ( MD5_CONTEXT *ctx, const unsigned char *data )
  84 {
  85   u32 correct_words[16];
  86   register u32 A = ctx->A;
  87   register u32 B = ctx->B;
  88   register u32 C = ctx->C;
  89   register u32 D = ctx->D;
  90   u32 *cwp = correct_words;
  91
  92 #ifdef WORDS_BIGENDIAN
  93   {
  94     int i;
  95     byte *p2, *p1;
  96     for(i=0, p1=data, p2=(byte*)correct_words; i < 16; i++, p2 += 4 )
  97       {
  98         p2[3] = *p1++;
  99         p2[2] = *p1++;
 100         p2[1] = *p1++;
 101         p2[0] = *p1++;
 102       }
 103   }
 104 #else
 105   memcpy( correct_words, data, 64 );
 106 #endif
 107
 108
 109 #define OP(a, b, c, d, s, T) \
 110   do                                       \
 111     {                                      \
 112       a += FF (b, c, d) + (*cwp++) + T;    \
 113       a = rol(a, s);                       \
 114       a += b;                              \
 115     }                                      \
 116   while (0)
 117
 118   /* Before we start, one word about the strange constants.
 119      They are defined in RFC 1321 as
 120
 121      T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
 122   */
 123
 124   /* Round 1.  */
 125   OP (A, B, C, D,  7, 0xd76aa478);
 126   OP (D, A, B, C, 12, 0xe8c7b756);
 127   OP (C, D, A, B, 17, 0x242070db);
 128   OP (B, C, D, A, 22, 0xc1bdceee);
 129   OP (A, B, C, D,  7, 0xf57c0faf);
 130   OP (D, A, B, C, 12, 0x4787c62a);
 131   OP (C, D, A, B, 17, 0xa8304613);
 132   OP (B, C, D, A, 22, 0xfd469501);
 133   OP (A, B, C, D,  7, 0x698098d8);
 134   OP (D, A, B, C, 12, 0x8b44f7af);
 135   OP (C, D, A, B, 17, 0xffff5bb1);
 136   OP (B, C, D, A, 22, 0x895cd7be);
 137   OP (A, B, C, D,  7, 0x6b901122);
 138   OP (D, A, B, C, 12, 0xfd987193);
 139   OP (C, D, A, B, 17, 0xa679438e);
 140   OP (B, C, D, A, 22, 0x49b40821);
 141
 142 #undef OP
 143 #define OP(f, a, b, c, d, k, s, T)  \
 144     do                                                                \
 145       {                                                               \
 146         a += f (b, c, d) + correct_words[k] + T;                      \
 147         a = rol(a, s);                                                \
 148         a += b;                                                       \
 149       }                                                               \
 150     while (0)
 151
 152   /* Round 2.  */
 153   OP (FG, A, B, C, D,  1,  5, 0xf61e2562);
 154   OP (FG, D, A, B, C,  6,  9, 0xc040b340);
 155   OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
 156   OP (FG, B, C, D, A,  0, 20, 0xe9b6c7aa);
 157   OP (FG, A, B, C, D,  5,  5, 0xd62f105d);
 158   OP (FG, D, A, B, C, 10,  9, 0x02441453);
 159   OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
 160   OP (FG, B, C, D, A,  4, 20, 0xe7d3fbc8);
 161   OP (FG, A, B, C, D,  9,  5, 0x21e1cde6);
 162   OP (FG, D, A, B, C, 14,  9, 0xc33707d6);
 163   OP (FG, C, D, A, B,  3, 14, 0xf4d50d87);
 164   OP (FG, B, C, D, A,  8, 20, 0x455a14ed);
 165   OP (FG, A, B, C, D, 13,  5, 0xa9e3e905);
 166   OP (FG, D, A, B, C,  2,  9, 0xfcefa3f8);
 167   OP (FG, C, D, A, B,  7, 14, 0x676f02d9);
 168   OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
 169
 170   /* Round 3.  */
 171   OP (FH, A, B, C, D,  5,  4, 0xfffa3942);
 172   OP (FH, D, A, B, C,  8, 11, 0x8771f681);
 173   OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
 174   OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
 175   OP (FH, A, B, C, D,  1,  4, 0xa4beea44);
 176   OP (FH, D, A, B, C,  4, 11, 0x4bdecfa9);
 177   OP (FH, C, D, A, B,  7, 16, 0xf6bb4b60);
 178   OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
 179   OP (FH, A, B, C, D, 13,  4, 0x289b7ec6);
 180   OP (FH, D, A, B, C,  0, 11, 0xeaa127fa);
 181   OP (FH, C, D, A, B,  3, 16, 0xd4ef3085);
 182   OP (FH, B, C, D, A,  6, 23, 0x04881d05);
 183   OP (FH, A, B, C, D,  9,  4, 0xd9d4d039);
 184   OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
 185   OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
 186   OP (FH, B, C, D, A,  2, 23, 0xc4ac5665);
 187
 188   /* Round 4.  */
 189   OP (FI, A, B, C, D,  0,  6, 0xf4292244);
 190   OP (FI, D, A, B, C,  7, 10, 0x432aff97);
 191   OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
 192   OP (FI, B, C, D, A,  5, 21, 0xfc93a039);
 193   OP (FI, A, B, C, D, 12,  6, 0x655b59c3);
 194   OP (FI, D, A, B, C,  3, 10, 0x8f0ccc92);
 195   OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
 196   OP (FI, B, C, D, A,  1, 21, 0x85845dd1);
 197   OP (FI, A, B, C, D,  8,  6, 0x6fa87e4f);
 198   OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
 199   OP (FI, C, D, A, B,  6, 15, 0xa3014314);
 200   OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
 201   OP (FI, A, B, C, D,  4,  6, 0xf7537e82);
 202   OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
 203   OP (FI, C, D, A, B,  2, 15, 0x2ad7d2bb);
 204   OP (FI, B, C, D, A,  9, 21, 0xeb86d391);
 205
 206   /* Put checksum in context given as argument.  */
 207   ctx->A += A;
 208   ctx->B += B;
 209   ctx->C += C;
 210   ctx->D += D;
 211 }
 212
 213
 214
 215 /* The routine updates the message-digest context to
 216  * account for the presence of each of the characters inBuf[0..inLen-1]
 217  * in the message whose digest is being computed.
 218  */
 219 static void
 220 md5_write( void *context, const void *inbuf_arg , size_t inlen)
 221 {
 222   const unsigned char *inbuf = inbuf_arg;
 223   MD5_CONTEXT *hd = context;
 224
 225   if( hd->count == 64 )  /* flush the buffer */
 226     {
 227       transform( hd, hd->buf );
 228       hd->count = 0;
 229       hd->nblocks++;
 230     }
 231   if( !inbuf )
 232     return;
 233
 234   if( hd->count )
 235     {
 236       for( ; inlen && hd->count < 64; inlen-- )
 237         hd->buf[hd->count++] = *inbuf++;
 238       md5_write( hd, NULL, 0 );
 239       if( !inlen )
 240         return;
 241     }
 242
 243   while( inlen >= 64 )
 244     {
 245       transform( hd, inbuf );
 246       hd->count = 0;
 247       hd->nblocks++;
 248       inlen -= 64;
 249       inbuf += 64;
 250     }
 251   for( ; inlen && hd->count < 64; inlen-- )
 252     hd->buf[hd->count++] = *inbuf++;
 253
 254 }
 255
 256
 257
 258 /* The routine final terminates the message-digest computation and
 259  * ends with the desired message digest in mdContext->digest[0...15].
 260  * The handle is prepared for a new MD5 cycle.
 261  * Returns 16 bytes representing the digest.
 262  */
 263
 264 static void
 265 md5_final( void *context)
 266 {
 267   MD5_CONTEXT *hd = context;
 268   u32 t, msb, lsb;
 269   byte *p;
 270
 271   md5_write(hd, NULL, 0); /* flush */;
 272
 273   t = hd->nblocks;
 274   /* multiply by 64 to make a byte count */
 275   lsb = t << 6;
 276   msb = t >> 26;
 277   /* add the count */
 278   t = lsb;
 279   if( (lsb += hd->count) < t )
 280     msb++;
 281   /* multiply by 8 to make a bit count */
 282   t = lsb;
 283   lsb <<= 3;
 284   msb <<= 3;
 285   msb |= t >> 29;
 286
 287   if( hd->count < 56 )  /* enough room */
 288     {
 289       hd->buf[hd->count++] = 0x80; /* pad */
 290       while( hd->count < 56 )
 291         hd->buf[hd->count++] = 0;  /* pad */
 292     }
 293   else  /* need one extra block */
 294     {
 295       hd->buf[hd->count++] = 0x80; /* pad character */
 296       while( hd->count < 64 )
 297         hd->buf[hd->count++] = 0;
 298       md5_write(hd, NULL, 0);  /* flush */;
 299       memset(hd->buf, 0, 56 ); /* fill next block with zeroes */
 300     }
 301   /* append the 64 bit count */
 302   hd->buf[56] = lsb        ;
 303   hd->buf[57] = lsb >>  8;
 304   hd->buf[58] = lsb >> 16;
 305   hd->buf[59] = lsb >> 24;
 306   hd->buf[60] = msb        ;
 307   hd->buf[61] = msb >>  8;
 308   hd->buf[62] = msb >> 16;
 309   hd->buf[63] = msb >> 24;
 310   transform( hd, hd->buf );
 311
 312   p = hd->buf;
 313 #ifdef WORDS_BIGENDIAN
 314 #define X(a) do { *p++ = hd->a      ; *p++ = hd->a >> 8;      \
 315                   *p++ = hd->a >> 16; *p++ = hd->a >> 24; } while(0)
 316 #else /* little endian */
 317 #define X(a) do { *(u32*)p = (*hd).a ; p += 4; } while(0)
 318 #endif
 319   X(A);
 320   X(B);
 321   X(C);
 322   X(D);
 323 #undef X
 324
 325 }
 326
 327 #if 0
 328 static byte *
 329 md5_read( void *context )
 330 {
 331   MD5_CONTEXT *hd = (MD5_CONTEXT *) context;
 332   return hd->buf;
 333 }
 334 #endif
 335
 336 void InitMD5( struct md5_s *h )
 337 {
 338     md5_init( h );
 339 }
 340
 341 void AddMD5( struct md5_s *restrict h, const void *data, size_t len )
 342 {
 343     md5_write( h, data, len );
 344 }
 345
 346 void EndMD5( struct md5_s *h )
 347 {
 348     md5_final( h );
 349 }