daapsharing/rb-daap-hash.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
   2  *
   3  *  Implementation of DAAP (iTunes Music Sharing) hashing, parsing, connection
   4  *
   5  *  Copyright (C) 2004,2005 Charles Schmidt <cschmidt2@emich.edu>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 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 General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA.
  20  *
  21  */
  22
  23 #include "config.h"
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <math.h>
  29 #ifdef HAVE_LIBZ
  30 #include <zlib.h>
  31 #endif
  32
  33 #include <glib.h>
  34
  35 #include "rb-daap-hash.h"
  36
  37 /* hashing - based on/copied from libopendaap
  38  * Copyright (c) 2004 David Hammerton
  39  */
  40
  41 typedef struct {
  42     guint32 buf[4];
  43     guint32 bits[2];
  44     unsigned char in[64];
  45     int version;
  46 } MD5_CTX;
  47
  48 /*
  49 * This code implements the MD5 message-digest algorithm.
  50 * The algorithm is due to Ron Rivest.  This code was
  51 * written by Colin Plumb in 1993, no copyright is claimed.
  52 * This code is in the public domain; do with it what you wish.
  53 *
  54 * Equivalent code is available from RSA Data Security, Inc.
  55 * This code has been tested against that, and is equivalent,
  56 * except that you don't need to include two pages of legalese
  57 * with every copy.
  58 *
  59 * To compute the message digest of a chunk of bytes, declare an MD5Context
  60 * structure, pass it to OpenDaap_MD5Init, call OpenDaap_MD5Update as needed
  61 * on buffers full of bytes, and then call OpenDaap_MD5Final, which will fill
  62 * a supplied 16-byte array with the digest.
  63 */
  64 static void
  65 MD5Transform (guint32 buf[4],
  66               guint32 const in[16],
  67               gint version);
  68 /* for some reason we still have to reverse bytes on bigendian machines
  69  * I don't really know why... but otherwise it fails..
  70  * Any MD5 gurus out there know why???
  71  */
  72 #if 0 //ndef WORDS_BIGENDIAN /* was: HIGHFIRST */
  73 #define byteReverse(buf, len)     /* Nothing */
  74 #else
  75 static void
  76 byteReverse (unsigned char *buf,
  77              unsigned longs);
  78
  79 #ifndef ASM_MD5
  80 /*
  81 * Note: this code is harmless on little-endian machines.
  82 */
  83 static void
  84 byteReverse (unsigned char *buf,
  85              unsigned longs)
  86 {
  87      guint32 t;
  88      do {
  89           t = (guint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
  90                ((unsigned) buf[1] << 8 | buf[0]);
  91           *(guint32 *) buf = t;
  92           buf += 4;
  93      } while (--longs);
  94 }
  95 #endif /* ! ASM_MD5 */
  96 #endif /* #if 0 */
  97
  98 static void
  99 OpenDaap_MD5Init (MD5_CTX *ctx,
 100                   gint version)
 101 {
 102     memset (ctx, 0, sizeof (MD5_CTX));
 103     ctx->buf[0] = 0x67452301;
 104     ctx->buf[1] = 0xefcdab89;
 105     ctx->buf[2] = 0x98badcfe;
 106     ctx->buf[3] = 0x10325476;
 107
 108     ctx->bits[0] = 0;
 109     ctx->bits[1] = 0;
 110
 111     ctx->version = version;
 112 }
 113
 114 static void
 115 OpenDaap_MD5Update (MD5_CTX *ctx,
 116                     unsigned char const *buf,
 117                     unsigned int len)
 118 {
 119     guint32 t;
 120
 121     /* Update bitcount */
 122
 123     t = ctx->bits[0];
 124     if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
 125         ctx->bits[1]++;          /* Carry from low to high */
 126     ctx->bits[1] += len >> 29;
 127
 128     t = (t >> 3) & 0x3f;     /* Bytes already in shsInfo->data */
 129
 130     /* Handle any leading odd-sized chunks */
 131
 132     if (t) {
 133         unsigned char *p = (unsigned char *) ctx->in + t;
 134
 135         t = 64 - t;
 136         if (len < t) {
 137             memcpy (p, buf, len);
 138             return;
 139         }
 140         memcpy (p, buf, t);
 141         byteReverse (ctx->in, 16);
 142         MD5Transform (ctx->buf, (guint32 *) ctx->in, ctx->version);
 143         buf += t;
 144         len -= t;
 145     }
 146     /* Process data in 64-byte chunks */
 147
 148     while (len >= 64) {
 149         memcpy (ctx->in, buf, 64);
 150         byteReverse (ctx->in, 16);
 151         MD5Transform (ctx->buf, (guint32 *) ctx->in, ctx->version);
 152         buf += 64;
 153         len -= 64;
 154     }
 155
 156     /* Handle any remaining bytes of data. */
 157
 158     memcpy (ctx->in, buf, len);
 159
 160 }
 161
 162 static void
 163 OpenDaap_MD5Final (MD5_CTX *ctx,
 164                    unsigned char digest[16])
 165 {
 166     unsigned count;
 167     unsigned char *p;
 168
 169     /* Compute number of bytes mod 64 */
 170     count = (ctx->bits[0] >> 3) & 0x3F;
 171
 172     /* Set the first char of padding to 0x80.  This is safe since there is
 173     always at least one byte free */
 174     p = ctx->in + count;
 175     *p++ = 0x80;
 176
 177     /* Bytes of padding needed to make 64 bytes */
 178     count = 64 - 1 - count;
 179
 180     /* Pad out to 56 mod 64 */
 181     if (count < 8) {
 182         /* Two lots of padding:  Pad the first block to 64 bytes */
 183         memset (p, 0, count);
 184         byteReverse (ctx->in, 16);
 185         MD5Transform (ctx->buf, (guint32 *) ctx->in, ctx->version);
 186
 187         /* Now fill the next block with 56 bytes */
 188         memset (ctx->in, 0, 56);
 189     } else {
 190         /* Pad block to 56 bytes */
 191         memset (p, 0, count - 8);
 192     }
 193     byteReverse (ctx->in, 14);
 194
 195     /* Append length in bits and transform */
 196     ((guint32 *) ctx->in)[14] = ctx->bits[0];
 197     ((guint32 *) ctx->in)[15] = ctx->bits[1];
 198
 199     MD5Transform (ctx->buf, (guint32 *) ctx->in, ctx->version);
 200     byteReverse ((unsigned char *) ctx->buf, 4);
 201     memcpy (digest, ctx->buf, 16);
 202     memset (ctx, 0, sizeof(ctx));     /* In case it's sensitive */
 203
 204     return;
 205 }
 206
 207 #ifndef ASM_MD5
 208
 209 /* The four core functions - F1 is optimized somewhat */
 210
 211 /* #define F1(x, y, z) (x & y | ~x & z) */
 212 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 213 #define F2(x, y, z) F1(z, x, y)
 214 #define F3(x, y, z) (x ^ y ^ z)
 215 #define F4(x, y, z) (y ^ (x | ~z))
 216
 217 /* This is the central step in the MD5 algorithm. */
 218 #define MD5STEP(f, w, x, y, z, data, s) \
 219 ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 220
 221 /*
 222 * The core of the MD5 algorithm, this alters an existing MD5 hash to reflect
 223 * the addition of 16 longwords of new data.  OpenDaap_MD5Update blocks the
 224 * data and converts bytes into longwords for this routine.
 225 */
 226 static void
 227 MD5Transform (guint32 buf[4],
 228               guint32 const in[16],
 229               gint version)
 230 {
 231     guint32 a, b, c, d;
 232
 233     a = buf[0];
 234     b = buf[1];
 235     c = buf[2];
 236     d = buf[3];
 237
 238     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 239     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 240     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 241     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 242     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 243     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 244     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 245     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 246     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 247     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 248     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 249     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 250     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 251     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 252     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 253     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 254
 255     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 256     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 257     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 258     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 259     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 260     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 261     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 262     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 263     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 264     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 265     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 266
 267     if (version == 1)
 268     {
 269         MD5STEP(F2, b, c, d, a, in[8] + 0x445a14ed, 20);
 270     }
 271     else
 272     {
 273         MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 274     }
 275     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 276     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 277     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 278     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 279
 280     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 281     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 282     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 283     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 284     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 285     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 286     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 287     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 288     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 289     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 290     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 291     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 292     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 293     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 294     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 295     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 296
 297     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 298     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 299     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 300     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 301     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 302     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 303     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 304     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 305     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 306     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 307     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 308     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 309     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 310     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 311     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 312     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 313
 314     buf[0] += a;
 315     buf[1] += b;
 316     buf[2] += c;
 317     buf[3] += d;
 318 }
 319
 320 #endif
 321
 322 static int staticHashDone = 0;
 323 static unsigned char staticHash_42[256*65] = {0};
 324 static unsigned char staticHash_45[256*65] = {0};
 325
 326 static const char hexchars[] = "0123456789ABCDEF";
 327 static char ac[] = "Dpqzsjhiu!3114!Bqqmf!Dpnqvufs-!Jod/"; /* +1 */
 328 static gboolean ac_unfudged = FALSE;
 329
 330 static void
 331 DigestToString (const unsigned char *digest,
 332                 char *string)
 333 {
 334     int i;
 335     for (i = 0; i < 16; i++)
 336     {
 337         unsigned char tmp = digest[i];
 338         string[i*2+1] = hexchars[tmp & 0x0f];
 339         string[i*2] = hexchars[(tmp >> 4) & 0x0f];
 340     }
 341 }
 342
 343 static void
 344 GenerateStatic_42 ()
 345 {
 346     MD5_CTX ctx;
 347     unsigned char *p = staticHash_42;
 348     int i;
 349     unsigned char buf[16];
 350
 351     for (i = 0; i < 256; i++)
 352     {
 353         OpenDaap_MD5Init (&ctx, 0);
 354
 355 #define MD5_STRUPDATE(str) OpenDaap_MD5Update(&ctx, (unsigned char const *)str, strlen(str))
 356
 357         if ((i & 0x80) != 0)
 358             MD5_STRUPDATE("Accept-Language");
 359         else
 360             MD5_STRUPDATE("user-agent");
 361
 362         if ((i & 0x40) != 0)
 363             MD5_STRUPDATE("max-age");
 364         else
 365             MD5_STRUPDATE("Authorization");
 366
 367         if ((i & 0x20) != 0)
 368             MD5_STRUPDATE("Client-DAAP-Version");
 369         else
 370             MD5_STRUPDATE("Accept-Encoding");
 371
 372         if ((i & 0x10) != 0)
 373             MD5_STRUPDATE("daap.protocolversion");
 374         else
 375             MD5_STRUPDATE("daap.songartist");
 376
 377         if ((i & 0x08) != 0)
 378             MD5_STRUPDATE("daap.songcomposer");
 379         else
 380             MD5_STRUPDATE("daap.songdatemodified");
 381
 382         if ((i & 0x04) != 0)
 383             MD5_STRUPDATE("daap.songdiscnumber");
 384         else
 385             MD5_STRUPDATE("daap.songdisabled");
 386
 387         if ((i & 0x02) != 0)
 388             MD5_STRUPDATE("playlist-item-spec");
 389         else
 390             MD5_STRUPDATE("revision-number");
 391
 392         if ((i & 0x01) != 0)
 393             MD5_STRUPDATE("session-id");
 394         else
 395             MD5_STRUPDATE("content-codes");
 396 #undef MD5_STRUPDATE
 397
 398         OpenDaap_MD5Final (&ctx, buf);
 399         DigestToString (buf, (char *)p);
 400         p += 65;
 401     }
 402 }
 403
 404 static void GenerateStatic_45()
 405 {
 406     MD5_CTX ctx;
 407     unsigned char *p = staticHash_45;
 408     int i;
 409     unsigned char buf[16];
 410
 411     for (i = 0; i < 256; i++)
 412     {
 413         OpenDaap_MD5Init (&ctx, 1);
 414
 415 #define MD5_STRUPDATE(str) OpenDaap_MD5Update(&ctx, (unsigned char const *)str, strlen(str))
 416
 417         if ((i & 0x40) != 0)
 418             MD5_STRUPDATE("eqwsdxcqwesdc");
 419         else
 420             MD5_STRUPDATE("op[;lm,piojkmn");
 421
 422         if ((i & 0x20) != 0)
 423             MD5_STRUPDATE("876trfvb 34rtgbvc");
 424         else
 425             MD5_STRUPDATE("=-0ol.,m3ewrdfv");
 426
 427         if ((i & 0x10) != 0)
 428             MD5_STRUPDATE("87654323e4rgbv ");
 429         else
 430             MD5_STRUPDATE("1535753690868867974342659792");
 431
 432         if ((i & 0x08) != 0)
 433             MD5_STRUPDATE("Song Name");
 434         else
 435             MD5_STRUPDATE("DAAP-CLIENT-ID:");
 436
 437         if ((i & 0x04) != 0)
 438             MD5_STRUPDATE("111222333444555");
 439         else
 440             MD5_STRUPDATE("4089961010");
 441
 442         if ((i & 0x02) != 0)
 443             MD5_STRUPDATE("playlist-item-spec");
 444         else
 445             MD5_STRUPDATE("revision-number");
 446
 447         if ((i & 0x01) != 0)
 448             MD5_STRUPDATE("session-id");
 449         else
 450             MD5_STRUPDATE("content-codes");
 451
 452         if ((i & 0x80) != 0)
 453             MD5_STRUPDATE("IUYHGFDCXWEDFGHN");
 454         else
 455             MD5_STRUPDATE("iuytgfdxwerfghjm");
 456
 457 #undef MD5_STRUPDATE
 458
 459         OpenDaap_MD5Final (&ctx, buf);
 460         DigestToString (buf, (char *)p);
 461         p += 65;
 462     }
 463 }
 464
 465 void
 466 rb_daap_hash_generate (short         version_major,
 467                        const guchar *url,
 468                        guchar        hash_select,
 469                        guchar       *out,
 470                        gint          request_id)
 471 {
 472     unsigned char buf[16];
 473     MD5_CTX ctx;
 474     int i;
 475
 476     unsigned char *hashTable = (version_major == 3) ?
 477                       staticHash_45 : staticHash_42;
 478
 479     if (!staticHashDone)
 480     {
 481         GenerateStatic_42 ();
 482         GenerateStatic_45 ();
 483         staticHashDone = 1;
 484     }
 485
 486     OpenDaap_MD5Init (&ctx, (version_major == 3) ? 1 : 0);
 487
 488     OpenDaap_MD5Update (&ctx, url, strlen ((const gchar*)url));
 489     if (ac_unfudged == FALSE) {
 490             for (i = 0; i < strlen (ac); i++) {
 491                 ac[i] = ac[i]-1;
 492             }
 493             ac_unfudged = TRUE;
 494     }
 495     OpenDaap_MD5Update (&ctx, (const guchar*)ac, strlen (ac));
 496
 497     OpenDaap_MD5Update (&ctx, &hashTable[hash_select * 65], 32);
 498
 499     if (request_id && version_major == 3)
 500     {
 501         char scribble[20];
 502         sprintf (scribble, "%u", request_id);
 503         OpenDaap_MD5Update (&ctx, (const guchar*)scribble, strlen (scribble));
 504     }
 505
 506     OpenDaap_MD5Final (&ctx, buf);
 507     DigestToString (buf, (char *)out);
 508
 509     return;
 510 }