src/fccache.c

   1 /*
   2  * $RCSId: xc/lib/fontconfig/src/fccache.c,v 1.12 2002/08/22 07:36:44 keithp Exp $
   3  *
   4  * Copyright © 2000 Keith Packard
   5  * Copyright © 2005 Patrick Lam
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and its
   8  * documentation for any purpose is hereby granted without fee, provided that
   9  * the above copyright notice appear in all copies and that both that
  10  * copyright notice and this permission notice appear in supporting
  11  * documentation, and that the name of Keith Packard not be used in
  12  * advertising or publicity pertaining to distribution of the software without
  13  * specific, written prior permission.  Keith Packard makes no
  14  * representations about the suitability of this software for any purpose.  It
  15  * is provided "as is" without express or implied warranty.
  16  *
  17  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  19  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  20  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  22  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  23  * PERFORMANCE OF THIS SOFTWARE.
  24  */
  25
  26 #include <fcntl.h>
  27 #include <dirent.h>
  28 #include <string.h>
  29 #include <sys/mman.h>
  30 #include <sys/utsname.h>
  31 #include <sys/types.h>
  32 #include <unistd.h>
  33 #include "fcint.h"
  34 #include <unistd.h>
  35
  36 #define ENDIAN_TEST 0x12345678
  37 #define MACHINE_SIGNATURE_SIZE 9 + 5*20 + 1
  38
  39 static int
  40 FcDirCacheOpen (const FcChar8 * dir);
  41
  42 static char *
  43 FcDirCacheHashName (char * cache_file, int collisions);
  44
  45 static off_t
  46 FcCacheSkipToArch (int fd, const char * arch);
  47
  48 static FcBool
  49 FcCacheCopyOld (int fd, int fd_orig, off_t start);
  50
  51 static void *
  52 FcDirCacheProduce (FcFontSet *set, FcCache * metadata);
  53
  54 static FcBool
  55 FcDirCacheConsume (int fd, const char * dir, FcFontSet *set, FcConfig *config);
  56
  57 static int
  58 FcCacheNextOffset(off_t w);
  59
  60 static char *
  61 FcCacheMachineSignature (void);
  62
  63 static FcBool
  64 FcCacheHaveBank (int bank);
  65
  66 static void
  67 FcCacheAddBankDir (int bank, const char * dir);
  68
  69 struct MD5Context {
  70         FcChar32 buf[4];
  71         FcChar32 bits[2];
  72         unsigned char in[64];
  73 };
  74
  75 static void MD5Init(struct MD5Context *ctx);
  76 static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len);
  77 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx);
  78 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16]);
  79
  80 #define FC_DBG_CACHE_REF    1024
  81
  82 static char *
  83 FcCacheReadString (int fd, char *dest, int len)
  84 {
  85     FcChar8     c;
  86     FcBool      escape;
  87     int         size;
  88     int         i;
  89
  90     if (len == 0)
  91         return 0;
  92
  93     size = len;
  94     i = 0;
  95     escape = FcFalse;
  96     while (read (fd, &c, 1) == 1)
  97     {
  98         if (!escape)
  99         {
 100             switch (c) {
 101             case '"':
 102                 c = '\0';
 103                 break;
 104             case '\\':
 105                 escape = FcTrue;
 106                 continue;
 107             }
 108         }
 109         if (i == size)
 110         {
 111             dest[i++] = 0;
 112             return dest;
 113         }
 114         dest[i++] = c;
 115         if (c == '\0')
 116             return dest;
 117         escape = FcFalse;
 118     }
 119     return 0;
 120 }
 121
 122 static void
 123 FcCacheSkipString (int fd)
 124 {
 125     FcChar8     c;
 126     FcBool      escape;
 127
 128     escape = FcFalse;
 129     while (read (fd, &c, 1) == 1)
 130     {
 131         if (!escape)
 132         {
 133             switch (c) {
 134             case '"':
 135                 c = '\0';
 136                 break;
 137             case '\\':
 138                 escape = FcTrue;
 139                 continue;
 140             }
 141         }
 142         if (c == '\0')
 143             return;
 144         escape = FcFalse;
 145     }
 146     return;
 147 }
 148
 149 static FcBool
 150 FcCacheWriteString (int fd, const char *chars)
 151 {
 152     if (write (fd, chars, strlen(chars)+1) != strlen(chars)+1)
 153         return FcFalse;
 154     return FcTrue;
 155 }
 156
 157 static void
 158 FcGlobalCacheDirDestroy (FcGlobalCacheDir *d)
 159 {
 160     FcStrSetDestroy (d->subdirs);
 161     FcMemFree (FC_MEM_STRING, strlen (d->name)+1);
 162     free (d->name);
 163     FcMemFree (FC_MEM_CACHE, sizeof (FcGlobalCacheDir));
 164     free (d);
 165 }
 166
 167 FcGlobalCache *
 168 FcGlobalCacheCreate (void)
 169 {
 170     FcGlobalCache   *cache;
 171
 172     cache = malloc (sizeof (FcGlobalCache));
 173     if (!cache)
 174         return 0;
 175     FcMemAlloc (FC_MEM_CACHE, sizeof (FcGlobalCache));
 176     cache->dirs = 0;
 177     cache->updated = FcFalse;
 178     cache->fd = -1;
 179     return cache;
 180 }
 181
 182 void
 183 FcGlobalCacheDestroy (FcGlobalCache *cache)
 184 {
 185     FcGlobalCacheDir    *d, *next;
 186
 187     for (d = cache->dirs; d; d = next)
 188     {
 189         next = d->next;
 190         FcGlobalCacheDirDestroy (d);
 191     }
 192     FcMemFree (FC_MEM_CACHE, sizeof (FcGlobalCache));
 193     free (cache);
 194 }
 195
 196 void
 197 FcGlobalCacheLoad (FcGlobalCache    *cache,
 198                    FcStrSet         *staleDirs,
 199                    const FcChar8    *cache_file,
 200                    FcConfig         *config)
 201 {
 202     char                name_buf[FC_MAX_FILE_LEN];
 203     FcGlobalCacheDir    *d, *next;
 204     FcFileTime          config_time = FcConfigModifiedTime (config);
 205     char                * current_arch_machine_name;
 206     char                candidate_arch_machine_name[MACHINE_SIGNATURE_SIZE + 9];
 207     off_t               current_arch_start;
 208
 209     struct stat         cache_stat, dir_stat;
 210     char                subdirName[FC_MAX_FILE_LEN + 1 + 12 + 1];
 211
 212     if (stat ((char *) cache_file, &cache_stat) < 0)
 213         return;
 214
 215     cache->fd = open ((char *) cache_file, O_RDONLY);
 216     if (cache->fd == -1)
 217         return;
 218
 219     cache->updated = FcFalse;
 220
 221     if (!FcCacheReadString (cache->fd, name_buf, sizeof (name_buf)))
 222         return;
 223     if (strcmp (name_buf, FC_GLOBAL_MAGIC_COOKIE) != 0)
 224         return;
 225
 226     current_arch_machine_name = FcCacheMachineSignature ();
 227     current_arch_start = FcCacheSkipToArch(cache->fd,
 228                                            current_arch_machine_name);
 229     if (current_arch_start < 0)
 230         goto bail_and_destroy;
 231
 232     lseek (cache->fd, current_arch_start, SEEK_SET);
 233     if (!FcCacheReadString (cache->fd, candidate_arch_machine_name,
 234                             sizeof (candidate_arch_machine_name)))
 235         goto bail_and_destroy;
 236     if (strlen(candidate_arch_machine_name) == 0)
 237         goto bail_and_destroy;
 238
 239     while (1)
 240     {
 241         off_t targ;
 242
 243         if (!FcCacheReadString (cache->fd, name_buf, sizeof (name_buf)) ||
 244             !strlen(name_buf))
 245             break;
 246
 247         /* Directory must be older than the global cache file; also
 248            cache must be newer than the config file. */
 249         if (stat ((char *) name_buf, &dir_stat) < 0 ||
 250             dir_stat.st_mtime > cache_stat.st_mtime ||
 251             (config_time.set && cache_stat.st_mtime < config_time.time))
 252         {
 253             FcCache md;
 254
 255             FcStrSetAdd (staleDirs, FcStrCopy ((FcChar8 *)name_buf));
 256             read (cache->fd, &md, sizeof (FcCache));
 257             lseek (cache->fd, FcCacheNextOffset (lseek(cache->fd, 0, SEEK_CUR)) + md.count, SEEK_SET);
 258             continue;
 259         }
 260
 261         d = malloc (sizeof (FcGlobalCacheDir));
 262         if (!d)
 263             goto bail1;
 264
 265         d->next = cache->dirs;
 266         cache->dirs = d;
 267
 268         d->name = (char *)FcStrCopy ((FcChar8 *)name_buf);
 269         d->ent = 0;
 270
 271         d->subdirs = FcStrSetCreate();
 272         do
 273         {
 274             if (!FcCacheReadString (cache->fd, subdirName,
 275                                     sizeof (subdirName)) ||
 276                 !strlen (subdirName))
 277                 break;
 278             FcStrSetAdd (d->subdirs, (FcChar8 *)subdirName);
 279         } while (1);
 280
 281         d->offset = lseek (cache->fd, 0, SEEK_CUR);
 282         if (read (cache->fd, &d->metadata, sizeof (FcCache)) != sizeof (FcCache))
 283             goto bail1;
 284         targ = FcCacheNextOffset (lseek(cache->fd, 0, SEEK_CUR)) + d->metadata.count;
 285         if (lseek (cache->fd, targ, SEEK_SET) != targ)
 286             goto bail1;
 287     }
 288     return;
 289
 290  bail1:
 291     for (d = cache->dirs; d; d = next)
 292     {
 293         next = d->next;
 294         free (d);
 295     }
 296     cache->dirs = 0;
 297
 298     close (cache->fd);
 299     cache->fd = -1;
 300     return;
 301
 302  bail_and_destroy:
 303     close (cache->fd);
 304     cache->fd = -1;
 305
 306     if (stat ((char *) cache_file, &cache_stat) == 0)
 307         unlink ((char *)cache_file);
 308
 309     return;
 310
 311 }
 312
 313 FcBool
 314 FcGlobalCacheReadDir (FcFontSet *set, FcStrSet *dirs, FcGlobalCache * cache, const char *dir, FcConfig *config)
 315 {
 316     FcGlobalCacheDir    *d;
 317     FcBool              ret = FcFalse;
 318     int                 i;
 319
 320     if (cache->fd == -1)
 321         return FcFalse;
 322
 323     if (!(dir = (char *)FcConfigNormalizeFontDir (config, (FcChar8 *)dir)))
 324         return FcFalse; /* non-existing directory */
 325
 326     for (d = cache->dirs; d; d = d->next)
 327     {
 328         if (strncmp (d->name, dir, strlen(dir)) == 0)
 329         {
 330             lseek (cache->fd, d->offset, SEEK_SET);
 331             if (!FcDirCacheConsume (cache->fd, d->name, set, config))
 332                 return FcFalse;
 333
 334             if (strcmp (d->name, dir) == 0)
 335             {
 336                 for (i = 0; i < d->subdirs->num; i++)
 337                     FcStrSetAdd (dirs, (FcChar8 *)d->subdirs->strs[i]);
 338
 339                 ret = FcTrue;
 340             }
 341         }
 342     }
 343
 344     return ret;
 345 }
 346
 347 FcBool
 348 FcGlobalCacheUpdate (FcGlobalCache  *cache,
 349                      FcStrSet       *dirs,
 350                      const char     *name,
 351                      FcFontSet      *set,
 352                      FcConfig       *config)
 353 {
 354     FcGlobalCacheDir    *d;
 355     int                 i;
 356
 357     name = (char *)FcConfigNormalizeFontDir (config, (FcChar8 *)name);
 358     for (d = cache->dirs; d; d = d->next)
 359     {
 360         if (strcmp(d->name, name) == 0)
 361             break;
 362     }
 363
 364     if (!d)
 365     {
 366         d = malloc (sizeof (FcGlobalCacheDir));
 367         if (!d)
 368             return FcFalse;
 369         d->next = cache->dirs;
 370         cache->dirs = d;
 371     }
 372
 373     cache->updated = FcTrue;
 374
 375     d->name = (char *)FcStrCopy ((FcChar8 *)name);
 376     d->ent = FcDirCacheProduce (set, &d->metadata);
 377     d->offset = 0;
 378     d->subdirs = FcStrSetCreate();
 379     for (i = 0; i < dirs->num; i++)
 380         FcStrSetAdd (d->subdirs, dirs->strs[i]);
 381     return FcTrue;
 382 }
 383
 384 FcBool
 385 FcGlobalCacheSave (FcGlobalCache    *cache,
 386                    const FcChar8    *cache_file,
 387                    FcConfig         *config)
 388 {
 389     int                 fd, fd_orig, i;
 390     FcGlobalCacheDir    *dir;
 391     FcAtomic            *atomic;
 392     off_t               current_arch_start = 0, truncate_to;
 393     char                * current_arch_machine_name, * header;
 394
 395     if (!cache->updated)
 396         return FcTrue;
 397
 398 #if defined (HAVE_GETUID) && defined (HAVE_GETEUID)
 399     /* Set-UID programs can't safely update the cache */
 400     if (getuid () != geteuid ())
 401         return FcFalse;
 402 #endif
 403
 404     atomic = FcAtomicCreate (cache_file);
 405     if (!atomic)
 406         return FcFalse;
 407
 408     if (!FcAtomicLock (atomic))
 409         goto bail1;
 410     fd = open ((char *) FcAtomicNewFile(atomic), O_RDWR | O_CREAT,
 411                S_IRUSR | S_IWUSR);
 412     if (fd == -1)
 413         goto bail2;
 414     FcCacheWriteString (fd, FC_GLOBAL_MAGIC_COOKIE);
 415
 416     fd_orig = open ((char *) FcAtomicOrigFile(atomic), O_RDONLY);
 417
 418     current_arch_machine_name = FcCacheMachineSignature ();
 419     if (fd_orig == -1)
 420         current_arch_start = 0;
 421     else
 422         current_arch_start = FcCacheSkipToArch (fd_orig,
 423                                                 current_arch_machine_name);
 424
 425     if (current_arch_start < 0)
 426     {
 427         off_t i = lseek(fd_orig, 0, SEEK_END);
 428         if (i < strlen (FC_GLOBAL_MAGIC_COOKIE)+1)
 429             i = strlen (FC_GLOBAL_MAGIC_COOKIE)+1;
 430         current_arch_start = FcCacheNextOffset (i);
 431     }
 432
 433     if (!FcCacheCopyOld(fd, fd_orig, current_arch_start))
 434         goto bail3;
 435
 436     close (fd_orig);
 437     fd_orig = -1;
 438
 439     current_arch_start = lseek(fd, 0, SEEK_CUR);
 440     if (ftruncate (fd, current_arch_start) == -1)
 441         goto bail3;
 442
 443     header = malloc (10 + strlen (current_arch_machine_name));
 444     if (!header)
 445         goto bail3;
 446
 447     truncate_to = current_arch_start + strlen(current_arch_machine_name) + 11;
 448     for (dir = cache->dirs; dir; dir = dir->next)
 449     {
 450         truncate_to += strlen(dir->name) + 1;
 451         truncate_to += sizeof (FcCache);
 452         truncate_to = FcCacheNextOffset (truncate_to);
 453         truncate_to += dir->metadata.count;
 454
 455         for (i = 0; i < dir->subdirs->size; i++)
 456             truncate_to += strlen((char *)dir->subdirs->strs[i]) + 1;
 457         truncate_to ++;
 458     }
 459     truncate_to -= current_arch_start;
 460
 461     sprintf (header, "%8x ", (int)truncate_to);
 462     strcat (header, current_arch_machine_name);
 463     if (!FcCacheWriteString (fd, header))
 464         goto bail4;
 465
 466     for (dir = cache->dirs; dir; dir = dir->next)
 467     {
 468         if (dir->name)
 469         {
 470             const char * d = (const char *)FcConfigNormalizeFontDir (config, (const FcChar8 *)dir->name);
 471
 472             FcCacheWriteString (fd, d);
 473
 474             for (i = 0; i < dir->subdirs->size; i++)
 475                 FcCacheWriteString (fd, (char *)dir->subdirs->strs[i]);
 476             FcCacheWriteString (fd, "");
 477
 478             write (fd, &dir->metadata, sizeof(FcCache));
 479             lseek (fd, FcCacheNextOffset (lseek(fd, 0, SEEK_CUR)), SEEK_SET);
 480             write (fd, dir->ent, dir->metadata.count);
 481             free (dir->ent);
 482         }
 483     }
 484     FcCacheWriteString (fd, "");
 485
 486     if (close (fd) == -1)
 487         goto bail25;
 488
 489     if (!FcAtomicReplaceOrig (atomic))
 490         goto bail25;
 491
 492     FcAtomicUnlock (atomic);
 493     FcAtomicDestroy (atomic);
 494
 495     cache->updated = FcFalse;
 496     return FcTrue;
 497
 498  bail4:
 499     free (header);
 500  bail3:
 501     if (fd_orig != -1)
 502         close (fd_orig);
 503
 504     close (fd);
 505  bail25:
 506     FcAtomicDeleteNew (atomic);
 507  bail2:
 508     FcAtomicUnlock (atomic);
 509  bail1:
 510     FcAtomicDestroy (atomic);
 511     return FcFalse;
 512 }
 513
 514 /*
 515  * Find the next presumably-mmapable offset after the supplied file
 516  * position.
 517  */
 518 static int
 519 FcCacheNextOffset(off_t w)
 520 {
 521     static long pagesize = -1;
 522     if (pagesize == -1)
 523         pagesize = sysconf(_SC_PAGESIZE);
 524     if (w % pagesize == 0)
 525         return w;
 526     else
 527         return ((w / pagesize)+1)*pagesize;
 528 }
 529
 530 /* return the address of the segment for the provided arch,
 531  * or -1 if arch not found */
 532 static off_t
 533 FcCacheSkipToArch (int fd, const char * arch)
 534 {
 535     char candidate_arch_machine_name_count[MACHINE_SIGNATURE_SIZE + 9];
 536     char * candidate_arch;
 537     off_t current_arch_start = 0;
 538
 539     lseek (fd, 0, SEEK_SET);
 540     FcCacheSkipString (fd);
 541     current_arch_start = lseek (fd, 0, SEEK_CUR);
 542
 543     /* skip arches that are not the current arch */
 544     while (1)
 545     {
 546         long bs;
 547
 548         if (lseek (fd, current_arch_start, SEEK_SET) != current_arch_start)
 549             return -1;
 550
 551         if (FcCacheReadString (fd, candidate_arch_machine_name_count,
 552                                 sizeof (candidate_arch_machine_name_count)) == 0)
 553             return -1;
 554         if (!strlen(candidate_arch_machine_name_count))
 555             return -1;
 556         bs = strtol(candidate_arch_machine_name_count, &candidate_arch, 16);
 557
 558         // count = 0 should probably be distinguished from the !bs condition
 559         if (!bs || bs < strlen (candidate_arch_machine_name_count))
 560             return -1;
 561
 562         candidate_arch++; /* skip leading space */
 563
 564         if (strcmp (candidate_arch, arch)==0)
 565             return current_arch_start;
 566         current_arch_start += bs;
 567     }
 568
 569     return -1;
 570 }
 571
 572 /* Cuts out the segment at the file pointer (moves everything else
 573  * down to cover it), and leaves the file pointer at the end of the
 574  * file. */
 575 static FcBool
 576 FcCacheCopyOld (int fd, int fd_orig, off_t start)
 577 {
 578     char * buf = malloc (8192);
 579     char candidate_arch_machine_name[MACHINE_SIGNATURE_SIZE + 9];
 580     long bs;
 581     int c, bytes_skipped;
 582     off_t loc;
 583
 584     if (!buf)
 585         return FcFalse;
 586
 587     loc = 0;
 588     lseek (fd, 0, SEEK_SET); lseek (fd_orig, 0, SEEK_SET);
 589     do
 590     {
 591         int b = 8192;
 592         if (loc + b > start)
 593             b = start - loc;
 594
 595         if ((c = read (fd_orig, buf, b)) <= 0)
 596             break;
 597         if (write (fd, buf, c) < 0)
 598             goto bail;
 599
 600         loc += c;
 601     }
 602     while (c > 0);
 603
 604     lseek (fd, start, SEEK_SET);
 605     if (FcCacheReadString (fd, candidate_arch_machine_name,
 606                            sizeof (candidate_arch_machine_name)) == 0)
 607         goto done;
 608     if (!strlen(candidate_arch_machine_name))
 609         goto done;
 610
 611     bs = strtol(candidate_arch_machine_name, 0, 16);
 612     if (bs == 0)
 613         goto done;
 614
 615     bytes_skipped = 0;
 616     do
 617     {
 618         lseek (fd, start+bs+bytes_skipped, SEEK_SET);
 619         if ((c = read (fd, buf, 8192)) <= 0)
 620             break;
 621         lseek (fd, start+bytes_skipped, SEEK_SET);
 622         if (write (fd, buf, c) < 0)
 623             goto bail;
 624         bytes_skipped += c;
 625     }
 626     while (c > 0);
 627     lseek (fd, start+bytes_skipped, SEEK_SET);
 628
 629  done:
 630     free (buf);
 631     return FcTrue;
 632
 633  bail:
 634     free (buf);
 635     return FcFalse;
 636 }
 637
 638 /* Does not check that the cache has the appropriate arch section. */
 639 /* Also, this can be fooled if the original location has a stale
 640  * cache, and the hashed location has an up-to-date cache.  Oh well,
 641  * sucks to be you in that case! */
 642 FcBool
 643 FcDirCacheValid (const FcChar8 *dir)
 644 {
 645     struct stat file_stat, dir_stat;
 646     int         fd;
 647
 648     if (stat ((char *) dir, &dir_stat) < 0)
 649         return FcFalse;
 650
 651     fd = FcDirCacheOpen (dir);
 652
 653     if (fd < 0)
 654         goto bail;
 655     if (fstat (fd, &file_stat) < 0)
 656         goto bail;
 657
 658     close (fd);
 659
 660     /*
 661      * If the directory has been modified more recently than
 662      * the cache file, the cache is not valid
 663      */
 664     if (dir_stat.st_mtime > file_stat.st_mtime)
 665         return FcFalse;
 666
 667     return FcTrue;
 668
 669  bail:
 670     close (fd);
 671     return FcFalse;
 672 }
 673
 674 /* Assumes that the cache file in 'dir' exists.
 675  * Checks that the cache has the appropriate arch section. */
 676 FcBool
 677 FcDirCacheHasCurrentArch (const FcChar8 *dir)
 678 {
 679     int         fd;
 680     off_t       current_arch_start;
 681     char        *current_arch_machine_name;
 682
 683     fd = FcDirCacheOpen (dir);
 684     if (fd < 0)
 685         goto bail;
 686
 687     current_arch_machine_name = FcCacheMachineSignature();
 688     current_arch_start = FcCacheSkipToArch(fd, current_arch_machine_name);
 689     close (fd);
 690
 691     if (current_arch_start < 0)
 692         return FcFalse;
 693
 694     return FcTrue;
 695
 696  bail:
 697     return FcFalse;
 698 }
 699
 700 FcBool
 701 FcDirCacheUnlink (const FcChar8 *dir, FcConfig *config)
 702 {
 703     char        *cache_file;
 704     char        *cache_hashed = 0;
 705     int         fd, collisions;
 706     struct stat cache_stat;
 707     char        name_buf[FC_MAX_FILE_LEN];
 708
 709     dir = FcConfigNormalizeFontDir (config, dir);
 710     cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
 711     if (!cache_file)
 712         return FcFalse;
 713
 714     /* First remove normal cache file. */
 715     if (stat ((char *) cache_file, &cache_stat) == 0 &&
 716         unlink ((char *)cache_file) != 0)
 717         goto bail;
 718
 719     /* Next remove any applicable hashed files. */
 720     fd = -1; collisions = 0;
 721     do
 722     {
 723         if (cache_hashed)
 724             FcStrFree ((FcChar8 *)cache_hashed);
 725
 726         cache_hashed = FcDirCacheHashName (cache_file, collisions++);
 727         if (!cache_hashed)
 728             goto bail;
 729
 730         if (fd > 0)
 731             close (fd);
 732         fd = open(cache_hashed, O_RDONLY);
 733         if (fd == -1)
 734         {
 735             FcStrFree ((FcChar8 *)cache_file);
 736             return FcTrue;
 737         }
 738
 739         if (!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || !strlen(name_buf))
 740         {
 741             FcStrFree ((FcChar8 *)cache_hashed);
 742             goto bail;
 743         }
 744     } while (strcmp (name_buf, cache_file) != 0);
 745
 746     FcStrFree ((FcChar8 *)cache_file);
 747     close (fd);
 748
 749     if (stat ((char *) cache_hashed, &cache_stat) == 0 &&
 750         unlink ((char *)cache_hashed) != 0)
 751     {
 752         FcStrFree ((FcChar8 *)cache_hashed);
 753         goto bail;
 754     }
 755
 756     FcStrFree ((FcChar8 *)cache_hashed);
 757     return FcTrue;
 758
 759  bail:
 760     FcStrFree ((FcChar8 *)cache_file);
 761     return FcFalse;
 762 }
 763
 764 static int
 765 FcCacheReadDirs (FcConfig * config, FcGlobalCache * cache,
 766                  FcStrList *list, FcFontSet * set)
 767 {
 768     int                 ret = 0;
 769     FcChar8             *dir;
 770     FcChar8             *file, *base;
 771     FcStrSet            *subdirs;
 772     FcStrList           *sublist;
 773     struct stat         statb;
 774
 775     /*
 776      * Read in the results from 'list'.
 777      */
 778     while ((dir = FcStrListNext (list)))
 779     {
 780         if (!FcConfigAcceptFilename (config, dir))
 781             continue;
 782
 783         /* freed below */
 784         file = (FcChar8 *) malloc (strlen ((char *) dir) + 1 + FC_MAX_FILE_LEN + 1);
 785         if (!file)
 786             return FcFalse;
 787
 788         strcpy ((char *) file, (char *) dir);
 789         strcat ((char *) file, "/");
 790         base = file + strlen ((char *) file);
 791
 792         subdirs = FcStrSetCreate ();
 793         if (!subdirs)
 794         {
 795             fprintf (stderr, "Can't create directory set\n");
 796             ret++;
 797             free (file);
 798             continue;
 799         }
 800
 801         if (access ((char *) dir, X_OK) < 0)
 802         {
 803             switch (errno) {
 804             case ENOENT:
 805             case ENOTDIR:
 806             case EACCES:
 807                 break;
 808             default:
 809                 fprintf (stderr, "\"%s\": ", dir);
 810                 perror ("");
 811                 ret++;
 812             }
 813             FcStrSetDestroy (subdirs);
 814             free (file);
 815             continue;
 816         }
 817         if (stat ((char *) dir, &statb) == -1)
 818         {
 819             fprintf (stderr, "\"%s\": ", dir);
 820             perror ("");
 821             FcStrSetDestroy (subdirs);
 822             ret++;
 823             free (file);
 824             continue;
 825         }
 826         if (!S_ISDIR (statb.st_mode))
 827         {
 828             fprintf (stderr, "\"%s\": not a directory, skipping\n", dir);
 829             FcStrSetDestroy (subdirs);
 830             free (file);
 831             continue;
 832         }
 833         if (!FcDirCacheValid (dir) || !FcDirCacheRead (set, subdirs, dir, config))
 834         {
 835             if (FcDebug () & FC_DBG_FONTSET)
 836                 printf ("cache scan dir %s\n", dir);
 837
 838             FcDirScanConfig (set, subdirs, cache,
 839                              config->blanks, dir, FcFalse, config);
 840         }
 841         sublist = FcStrListCreate (subdirs);
 842         FcStrSetDestroy (subdirs);
 843         if (!sublist)
 844         {
 845             fprintf (stderr, "Can't create subdir list in \"%s\"\n", dir);
 846             ret++;
 847             free (file);
 848             continue;
 849         }
 850         ret += FcCacheReadDirs (config, cache, sublist, set);
 851         free (file);
 852     }
 853     FcStrListDone (list);
 854     return ret;
 855 }
 856
 857 FcFontSet *
 858 FcCacheRead (FcConfig *config, FcGlobalCache * cache)
 859 {
 860     FcFontSet * s = FcFontSetCreate();
 861     if (!s)
 862         return 0;
 863
 864     if (FcCacheReadDirs (config, cache, FcConfigGetConfigDirs (config), s))
 865         goto bail;
 866
 867     return s;
 868
 869  bail:
 870     FcFontSetDestroy (s);
 871     return 0;
 872 }
 873
 874 static const char bin2hex[] = { '0', '1', '2', '3',
 875                                 '4', '5', '6', '7',
 876                                 '8', '9', 'a', 'b',
 877                                 'c', 'd', 'e', 'f' };
 878
 879 static char *
 880 FcDirCacheHashName (char * cache_file, int collisions)
 881 {
 882     unsigned char       hash[16], hex_hash[33];
 883     char                *cache_hashed;
 884     unsigned char       uscore = '_';
 885     int                 cnt, i;
 886     FcChar8             *tmp;
 887     struct MD5Context   ctx;
 888
 889     MD5Init (&ctx);
 890     MD5Update (&ctx, (unsigned char *)cache_file, strlen (cache_file));
 891
 892     for (i = 0; i < collisions; i++)
 893         MD5Update (&ctx, &uscore, 1);
 894
 895     MD5Final (hash, &ctx);
 896
 897     for (cnt = 0; cnt < 16; ++cnt)
 898     {
 899         hex_hash[2*cnt] = bin2hex[hash[cnt] >> 4];
 900         hex_hash[2*cnt+1] = bin2hex[hash[cnt] & 0xf];
 901     }
 902     hex_hash[32] = 0;
 903
 904     tmp = FcStrPlus ((FcChar8 *)hex_hash, (FcChar8 *)FC_CACHE_SUFFIX);
 905     if (!tmp)
 906         return 0;
 907
 908     cache_hashed = (char *)FcStrPlus ((FcChar8 *)PKGCACHEDIR"/", tmp);
 909     free (tmp);
 910
 911     return cache_hashed;
 912 }
 913
 914 /* Opens the hashed name for cache_file.
 915  * This would fail in the unlikely event of a collision and subsequent
 916  * removal of the file which originally caused the collision. */
 917 static int
 918 FcDirCacheOpen (const FcChar8 *dir)
 919 {
 920     FcBool      found;
 921     int         fd = -1, collisions = 0;
 922     char        *cache_file, *cache_hashed;
 923     char        name_buf[FC_MAX_FILE_LEN];
 924     struct stat dir_stat;
 925
 926     cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
 927     if (!cache_file)
 928         return -1;
 929
 930     fd = open(cache_file, O_RDONLY);
 931     if (fd != -1)
 932         return fd;
 933
 934     if (stat ((char *)dir, &dir_stat) == -1)
 935         return -1;
 936
 937     found = FcFalse;
 938     do
 939     {
 940         struct stat c;
 941         FcChar8 * name_buf_dir;
 942
 943         cache_hashed = FcDirCacheHashName (cache_file, collisions++);
 944         if (!cache_hashed)
 945         {
 946             FcStrFree ((FcChar8 *)cache_file);
 947             return -1;
 948         }
 949
 950         if (fd > 0)
 951             close (fd);
 952         fd = open(cache_hashed, O_RDONLY);
 953         FcStrFree ((FcChar8 *)cache_hashed);
 954
 955         if (fd == -1)
 956         {
 957             FcStrFree ((FcChar8 *)cache_file);
 958             return -1;
 959         }
 960         if (!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || !strlen(name_buf))
 961             goto bail;
 962
 963         name_buf_dir = FcStrDirname ((FcChar8 *)name_buf);
 964         if (stat ((char *)name_buf_dir, &c) == -1)
 965         {
 966             FcStrFree (name_buf_dir);
 967             continue;
 968         }
 969         FcStrFree (name_buf_dir);
 970         found = (c.st_ino == dir_stat.st_ino) && (c.st_dev == dir_stat.st_dev);
 971     } while (!found);
 972     FcStrFree ((FcChar8 *)cache_file);
 973     return fd;
 974
 975  bail:
 976     FcStrFree ((FcChar8 *)cache_file);
 977     close (fd);
 978     return -1;
 979 }
 980
 981 /* read serialized state from the cache file */
 982 FcBool
 983 FcDirCacheRead (FcFontSet * set, FcStrSet * dirs, const FcChar8 *dir, FcConfig *config)
 984 {
 985     int         fd;
 986     char        *current_arch_machine_name;
 987     char        candidate_arch_machine_name[9+MACHINE_SIGNATURE_SIZE];
 988     off_t       current_arch_start = 0;
 989     char        subdirName[FC_MAX_FILE_LEN + 1 + 12 + 1];
 990
 991     fd = FcDirCacheOpen (dir);
 992     if (fd < 0)
 993         goto bail;
 994
 995     current_arch_machine_name = FcCacheMachineSignature();
 996     current_arch_start = FcCacheSkipToArch(fd,
 997                                            current_arch_machine_name);
 998     if (current_arch_start < 0)
 999         goto bail1;
1000
1001     lseek (fd, current_arch_start, SEEK_SET);
1002     if (FcCacheReadString (fd, candidate_arch_machine_name,
1003                            sizeof (candidate_arch_machine_name)) == 0)
1004         goto bail1;
1005
1006     while (FcCacheReadString (fd, subdirName, sizeof (subdirName)) && strlen (subdirName) > 0)
1007         FcStrSetAdd (dirs, (FcChar8 *)subdirName);
1008
1009     if (!FcDirCacheConsume (fd, (const char *)dir, set, config))
1010         goto bail1;
1011
1012     close(fd);
1013     return FcTrue;
1014
1015  bail1:
1016     close (fd);
1017  bail:
1018     return FcFalse;
1019 }
1020
1021 static FcBool
1022 FcDirCacheConsume (int fd, const char * dir, FcFontSet *set, FcConfig *config)
1023 {
1024     FcCache metadata;
1025     void * current_dir_block;
1026     off_t pos;
1027
1028     read(fd, &metadata, sizeof(FcCache));
1029     if (metadata.magic != FC_CACHE_MAGIC)
1030         return FcFalse;
1031
1032     if (!metadata.count)
1033     {
1034         pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR));
1035         lseek (fd, pos, SEEK_SET);
1036         if (config)
1037             FcConfigAddFontDir (config, (FcChar8 *)dir);
1038         return FcTrue;
1039     }
1040
1041     pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR));
1042     current_dir_block = mmap (0, metadata.count,
1043                               PROT_READ, MAP_SHARED, fd, pos);
1044     lseek (fd, pos+metadata.count, SEEK_SET);
1045     if (current_dir_block == MAP_FAILED)
1046         return FcFalse;
1047
1048     FcCacheAddBankDir (metadata.bank, dir);
1049     if (config)
1050         FcConfigAddFontDir (config, (FcChar8 *)dir);
1051
1052     if (!FcFontSetUnserialize (&metadata, set, current_dir_block))
1053         return FcFalse;
1054
1055     return FcTrue;
1056 }
1057
1058 static void *
1059 FcDirCacheProduce (FcFontSet *set, FcCache *metadata)
1060 {
1061     void * current_dir_block, * final_dir_block;
1062     static unsigned int rand_state = 0;
1063     int bank, needed_bytes_no_align;
1064
1065     if (!rand_state)
1066         rand_state = time(0L);
1067     bank = rand_r(&rand_state);
1068
1069     while (FcCacheHaveBank(bank))
1070         bank = rand_r(&rand_state);
1071
1072     memset (metadata, 0, sizeof(FcCache));
1073     FcFontSetNewBank();
1074     needed_bytes_no_align = FcFontSetNeededBytes (set);
1075     metadata->count = needed_bytes_no_align +
1076         FcFontSetNeededBytesAlign ();
1077     metadata->magic = FC_CACHE_MAGIC;
1078     metadata->bank = bank;
1079
1080     if (!needed_bytes_no_align) /* not a failure, no fonts to write */
1081     {
1082         /* no, you don't really need to write any bytes at all. */
1083         metadata->count = 0;
1084         return 0;
1085     }
1086
1087     current_dir_block = malloc (metadata->count);
1088     if (!current_dir_block)
1089         goto bail;
1090     // shut up valgrind
1091     memset (current_dir_block, 0, metadata->count);
1092     final_dir_block = FcFontSetDistributeBytes (metadata, current_dir_block);
1093
1094     if ((void *)((char *)current_dir_block+metadata->count) < final_dir_block)
1095         goto bail;
1096
1097     if (!FcFontSetSerialize (bank, set))
1098         goto bail;
1099
1100     return current_dir_block;
1101
1102  bail:
1103     free (current_dir_block);
1104     return 0;
1105 }
1106
1107 /* write serialized state to the cache file */
1108 FcBool
1109 FcDirCacheWrite (FcFontSet *set, FcStrSet *dirs, const FcChar8 *dir)
1110 {
1111     char            *cache_file;
1112     char            *cache_hashed;
1113     int             fd, fd_orig, i, dirs_count;
1114     FcAtomic        *atomic;
1115     FcCache         metadata;
1116     off_t           current_arch_start = 0, truncate_to;
1117     char            name_buf[FC_MAX_FILE_LEN];
1118     int             collisions;
1119
1120     char            *current_arch_machine_name, * header;
1121     void            *current_dir_block = 0;
1122
1123     dir = FcConfigNormalizeFontDir (FcConfigGetCurrent(), dir);
1124     if (!dir)
1125         return FcFalse;
1126
1127     cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
1128     if (!cache_file)
1129         goto bail;
1130
1131     /* Ensure that we're not trampling a cache for some other dir. */
1132     /* This is slightly different from FcDirCacheOpen, since it
1133      * needs the filename, not the file descriptor. */
1134     fd = -1; collisions = 0;
1135     do
1136     {
1137         cache_hashed = FcDirCacheHashName (cache_file, collisions++);
1138         if (!cache_hashed)
1139             goto bail0;
1140
1141         if (fd > 0)
1142             close (fd);
1143         fd = open(cache_hashed, O_RDONLY);
1144         if (fd == -1)
1145             break;
1146         if(!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || !strlen(name_buf))
1147         {
1148             close (fd);
1149             break;
1150         }
1151         close (fd);
1152
1153         if (strcmp (name_buf, cache_file) != 0)
1154             continue;
1155     } while (0);
1156
1157     current_dir_block = FcDirCacheProduce (set, &metadata);
1158
1159     if (metadata.count && !current_dir_block)
1160         goto bail1;
1161
1162     if (FcDebug () & FC_DBG_CACHE)
1163         printf ("FcDirCacheWriteDir cache_file \"%s\"\n", cache_file);
1164
1165     atomic = FcAtomicCreate ((FcChar8 *)cache_hashed);
1166     if (!atomic)
1167         goto bail1;
1168
1169     if (!FcAtomicLock (atomic))
1170     {
1171         /* Now try rewriting the original version of the file. */
1172         FcAtomicDestroy (atomic);
1173
1174         atomic = FcAtomicCreate ((FcChar8 *)cache_file);
1175         fd_orig = open (cache_file, O_RDONLY);
1176         if (fd_orig == -1)
1177             fd_orig = open((char *)FcAtomicOrigFile (atomic), O_RDONLY);
1178
1179         fd = open((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT, 0666);
1180         if (fd == -1)
1181             goto bail2;
1182     }
1183
1184     /* In all cases, try opening the real location of the cache file first. */
1185     /* (even if that's not atomic.) */
1186     fd_orig = open (cache_file, O_RDONLY);
1187     if (fd_orig == -1)
1188         fd_orig = open((char *)FcAtomicOrigFile (atomic), O_RDONLY);
1189
1190     fd = open((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT, 0666);
1191     if (fd == -1)
1192         goto bail3;
1193
1194     FcCacheWriteString (fd, cache_file);
1195
1196     current_arch_machine_name = FcCacheMachineSignature ();
1197     current_arch_start = 0;
1198
1199     if (fd_orig != -1)
1200         current_arch_start =
1201             FcCacheSkipToArch(fd_orig, current_arch_machine_name);
1202
1203     if (current_arch_start < 0)
1204     {
1205         off_t i = lseek(fd_orig, 0, SEEK_END);
1206         if (i < strlen (FC_GLOBAL_MAGIC_COOKIE)+1)
1207             i = strlen (FC_GLOBAL_MAGIC_COOKIE)+1;
1208         current_arch_start = FcCacheNextOffset (i);
1209     }
1210
1211     if (fd_orig != -1 && !FcCacheCopyOld(fd, fd_orig, current_arch_start))
1212         goto bail4;
1213
1214     if (fd_orig != -1)
1215         close (fd_orig);
1216
1217     current_arch_start = lseek(fd, 0, SEEK_CUR);
1218     if (ftruncate (fd, current_arch_start) == -1)
1219         goto bail4;
1220
1221     /* allocate space for subdir names in this block */
1222     dirs_count = 0;
1223     for (i = 0; i < dirs->size; i++)
1224         dirs_count += strlen((char *)dirs->strs[i]) + 1;
1225     dirs_count ++;
1226
1227     /* now write the address of the next offset */
1228     truncate_to = FcCacheNextOffset (FcCacheNextOffset (current_arch_start + sizeof (FcCache) + dirs_count) + metadata.count) - current_arch_start;
1229     header = malloc (10 + strlen (current_arch_machine_name));
1230     if (!header)
1231         goto bail4;
1232     sprintf (header, "%8x ", (int)truncate_to);
1233     strcat (header, current_arch_machine_name);
1234     if (!FcCacheWriteString (fd, header))
1235         goto bail5;
1236
1237     for (i = 0; i < dirs->size; i++)
1238         FcCacheWriteString (fd, (char *)dirs->strs[i]);
1239     FcCacheWriteString (fd, "");
1240
1241     write (fd, &metadata, sizeof(FcCache));
1242     if (metadata.count)
1243     {
1244         lseek (fd, FcCacheNextOffset (lseek(fd, 0, SEEK_END)), SEEK_SET);
1245         write (fd, current_dir_block, metadata.count);
1246         free (current_dir_block);
1247     }
1248
1249     /* this actually serves to pad out the cache file, if needed */
1250     if (ftruncate (fd, current_arch_start + truncate_to) == -1)
1251         goto bail5;
1252
1253     free (header);
1254     close(fd);
1255     if (!FcAtomicReplaceOrig(atomic))
1256         goto bail5;
1257     FcStrFree ((FcChar8 *)cache_hashed);
1258     FcStrFree ((FcChar8 *)cache_file);
1259     FcAtomicUnlock (atomic);
1260     FcAtomicDestroy (atomic);
1261     return FcTrue;
1262
1263  bail5:
1264     free (header);
1265  bail4:
1266     close (fd);
1267  bail3:
1268     FcAtomicUnlock (atomic);
1269  bail2:
1270     FcAtomicDestroy (atomic);
1271  bail1:
1272     FcStrFree ((FcChar8 *)cache_hashed);
1273  bail0:
1274     unlink ((char *)cache_file);
1275     FcStrFree ((FcChar8 *)cache_file);
1276     if (current_dir_block)
1277         free (current_dir_block);
1278  bail:
1279     return FcFalse;
1280 }
1281
1282 static char *
1283 FcCacheMachineSignature ()
1284 {
1285     static char buf[MACHINE_SIGNATURE_SIZE];
1286     int32_t magic = ENDIAN_TEST;
1287     char * m = (char *)&magic;
1288
1289     sprintf (buf, "%2x%2x%2x%2x "
1290              "%4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x "
1291              "%4x %4x %4x %4x %4x %4x %4x %4x\n",
1292              m[0], m[1], m[2], m[3],
1293              (unsigned int)sizeof (char),
1294              (unsigned int)sizeof (char *),
1295              (unsigned int)sizeof (int),
1296              (unsigned int)sizeof (FcPattern),
1297              (unsigned int)sizeof (FcPatternEltPtr),
1298              (unsigned int)sizeof (struct _FcPatternElt *),
1299              (unsigned int)sizeof (FcPatternElt),
1300              (unsigned int)sizeof (FcObjectPtr),
1301              (unsigned int)sizeof (FcValueListPtr),
1302              (unsigned int)sizeof (FcValue),
1303              (unsigned int)sizeof (FcValueBinding),
1304              (unsigned int)sizeof (struct _FcValueList *),
1305              (unsigned int)sizeof (FcCharSet),
1306              (unsigned int)sizeof (FcCharLeaf **),
1307              (unsigned int)sizeof (FcChar16 *),
1308              (unsigned int)sizeof (FcChar16),
1309              (unsigned int)sizeof (FcCharLeaf),
1310              (unsigned int)sizeof (FcChar32),
1311              (unsigned int)sizeof (FcCache),
1312              (unsigned int)sysconf(_SC_PAGESIZE));
1313
1314     return buf;
1315 }
1316
1317 static int banks_ptr = 0, banks_alloc = 0;
1318 int * _fcBankId = 0, * _fcBankIdx = 0;
1319 static const char ** bankDirs = 0;
1320
1321 static FcBool
1322 FcCacheHaveBank (int bank)
1323 {
1324     int i;
1325
1326     if (bank < FC_BANK_FIRST)
1327         return FcTrue;
1328
1329     for (i = 0; i < banks_ptr; i++)
1330         if (_fcBankId[i] == bank)
1331             return FcTrue;
1332
1333     return FcFalse;
1334 }
1335
1336 int
1337 FcCacheBankToIndexMTF (int bank)
1338 {
1339     int i, j;
1340
1341     for (i = 0; i < banks_ptr; i++)
1342         if (_fcBankId[_fcBankIdx[i]] == bank)
1343         {
1344             int t = _fcBankIdx[i];
1345
1346             for (j = i; j > 0; j--)
1347                 _fcBankIdx[j] = _fcBankIdx[j-1];
1348             _fcBankIdx[0] = t;
1349             return t;
1350         }
1351
1352     if (banks_ptr >= banks_alloc)
1353     {
1354         int * b, * bidx;
1355         const char ** bds;
1356
1357         b = realloc (_fcBankId, (banks_alloc + 4) * sizeof(int));
1358         if (!b)
1359             return -1;
1360         _fcBankId = b;
1361
1362         bidx = realloc (_fcBankIdx, (banks_alloc + 4) * sizeof(int));
1363         if (!bidx)
1364             return -1;
1365         _fcBankIdx = bidx;
1366
1367         bds = realloc (bankDirs, (banks_alloc + 4) * sizeof (char *));
1368         if (!bds)
1369             return -1;
1370         bankDirs = bds;
1371
1372         banks_alloc += 4;
1373     }
1374
1375     i = banks_ptr++;
1376     _fcBankId[i] = bank;
1377     _fcBankIdx[i] = i;
1378     return i;
1379 }
1380
1381 static void
1382 FcCacheAddBankDir (int bank, const char * dir)
1383 {
1384     int bi = FcCacheBankToIndexMTF (bank);
1385
1386     if (bi < 0)
1387         return;
1388
1389     bankDirs[bi] = (const char *)FcStrCopy ((FcChar8 *)dir);
1390 }
1391
1392 const char *
1393 FcCacheFindBankDir (int bank)
1394 {
1395     int bi = FcCacheBankToIndex (bank);
1396     return bankDirs[bi];
1397 }
1398
1399 /*
1400  * This code implements the MD5 message-digest algorithm.
1401  * The algorithm is due to Ron Rivest.  This code was
1402  * written by Colin Plumb in 1993, no copyright is claimed.
1403  * This code is in the public domain; do with it what you wish.
1404  *
1405  * Equivalent code is available from RSA Data Security, Inc.
1406  * This code has been tested against that, and is equivalent,
1407  * except that you don't need to include two pages of legalese
1408  * with every copy.
1409  *
1410  * To compute the message digest of a chunk of bytes, declare an
1411  * MD5Context structure, pass it to MD5Init, call MD5Update as
1412  * needed on buffers full of bytes, and then call MD5Final, which
1413  * will fill a supplied 16-byte array with the digest.
1414  */
1415
1416 #ifndef HIGHFIRST
1417 #define byteReverse(buf, len)   /* Nothing */
1418 #else
1419 /*
1420  * Note: this code is harmless on little-endian machines.
1421  */
1422 void byteReverse(unsigned char *buf, unsigned longs)
1423 {
1424     FcChar32 t;
1425     do {
1426         t = (FcChar32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
1427             ((unsigned) buf[1] << 8 | buf[0]);
1428         *(FcChar32 *) buf = t;
1429         buf += 4;
1430     } while (--longs);
1431 }
1432 #endif
1433
1434 /*
1435  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
1436  * initialization constants.
1437  */
1438 static void MD5Init(struct MD5Context *ctx)
1439 {
1440     ctx->buf[0] = 0x67452301;
1441     ctx->buf[1] = 0xefcdab89;
1442     ctx->buf[2] = 0x98badcfe;
1443     ctx->buf[3] = 0x10325476;
1444
1445     ctx->bits[0] = 0;
1446     ctx->bits[1] = 0;
1447 }
1448
1449 /*
1450  * Update context to reflect the concatenation of another buffer full
1451  * of bytes.
1452  */
1453 static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len)
1454 {
1455     FcChar32 t;
1456
1457     /* Update bitcount */
1458
1459     t = ctx->bits[0];
1460     if ((ctx->bits[0] = t + ((FcChar32) len << 3)) < t)
1461         ctx->bits[1]++;         /* Carry from low to high */
1462     ctx->bits[1] += len >> 29;
1463
1464     t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
1465
1466     /* Handle any leading odd-sized chunks */
1467
1468     if (t) {
1469         unsigned char *p = (unsigned char *) ctx->in + t;
1470
1471         t = 64 - t;
1472         if (len < t) {
1473             memcpy(p, buf, len);
1474             return;
1475         }
1476         memcpy(p, buf, t);
1477         byteReverse(ctx->in, 16);
1478         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
1479         buf += t;
1480         len -= t;
1481     }
1482     /* Process data in 64-byte chunks */
1483
1484     while (len >= 64) {
1485         memcpy(ctx->in, buf, 64);
1486         byteReverse(ctx->in, 16);
1487         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
1488         buf += 64;
1489         len -= 64;
1490     }
1491
1492     /* Handle any remaining bytes of data. */
1493
1494     memcpy(ctx->in, buf, len);
1495 }
1496
1497 /*
1498  * Final wrapup - pad to 64-byte boundary with the bit pattern
1499  * 1 0* (64-bit count of bits processed, MSB-first)
1500  */
1501 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
1502 {
1503     unsigned count;
1504     unsigned char *p;
1505
1506     /* Compute number of bytes mod 64 */
1507     count = (ctx->bits[0] >> 3) & 0x3F;
1508
1509     /* Set the first char of padding to 0x80.  This is safe since there is
1510        always at least one byte free */
1511     p = ctx->in + count;
1512     *p++ = 0x80;
1513
1514     /* Bytes of padding needed to make 64 bytes */
1515     count = 64 - 1 - count;
1516
1517     /* Pad out to 56 mod 64 */
1518     if (count < 8) {
1519         /* Two lots of padding:  Pad the first block to 64 bytes */
1520         memset(p, 0, count);
1521         byteReverse(ctx->in, 16);
1522         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
1523
1524         /* Now fill the next block with 56 bytes */
1525         memset(ctx->in, 0, 56);
1526     } else {
1527         /* Pad block to 56 bytes */
1528         memset(p, 0, count - 8);
1529     }
1530     byteReverse(ctx->in, 14);
1531
1532     /* Append length in bits and transform */
1533     ((FcChar32 *) ctx->in)[14] = ctx->bits[0];
1534     ((FcChar32 *) ctx->in)[15] = ctx->bits[1];
1535
1536     MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
1537     byteReverse((unsigned char *) ctx->buf, 4);
1538     memcpy(digest, ctx->buf, 16);
1539     memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
1540 }
1541
1542
1543 /* The four core functions - F1 is optimized somewhat */
1544
1545 /* #define F1(x, y, z) (x & y | ~x & z) */
1546 #define F1(x, y, z) (z ^ (x & (y ^ z)))
1547 #define F2(x, y, z) F1(z, x, y)
1548 #define F3(x, y, z) (x ^ y ^ z)
1549 #define F4(x, y, z) (y ^ (x | ~z))
1550
1551 /* This is the central step in the MD5 algorithm. */
1552 #define MD5STEP(f, w, x, y, z, data, s) \
1553         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
1554
1555 /*
1556  * The core of the MD5 algorithm, this alters an existing MD5 hash to
1557  * reflect the addition of 16 longwords of new data.  MD5Update blocks
1558  * the data and converts bytes into longwords for this routine.
1559  */
1560 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16])
1561 {
1562     register FcChar32 a, b, c, d;
1563
1564     a = buf[0];
1565     b = buf[1];
1566     c = buf[2];
1567     d = buf[3];
1568
1569     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
1570     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
1571     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
1572     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
1573     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
1574     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
1575     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
1576     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
1577     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
1578     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
1579     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
1580     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
1581     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
1582     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
1583     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
1584     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
1585
1586     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
1587     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
1588     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
1589     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
1590     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
1591     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
1592     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
1593     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
1594     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
1595     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
1596     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
1597     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
1598     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
1599     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
1600     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
1601     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
1602
1603     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
1604     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
1605     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
1606     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
1607     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
1608     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
1609     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
1610     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
1611     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
1612     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
1613     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
1614     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
1615     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
1616     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
1617     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
1618     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
1619
1620     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
1621     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
1622     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
1623     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
1624     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
1625     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
1626     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
1627     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
1628     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
1629     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
1630     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
1631     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
1632     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
1633     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
1634     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
1635     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
1636
1637     buf[0] += a;
1638     buf[1] += b;
1639     buf[2] += c;
1640     buf[3] += d;
1641 }