aboutsummaryrefslogtreecommitdiff
path: root/src/or/dirserv.c
blob: d74d4d0a004373dde8f39556178ab07c4babfa5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
/* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */

#include "or.h"

/**
 * \file dirserv.c
 * \brief Directory server core implementation.
 **/

/** How far in the future do we allow a router to get? (seconds) */
#define ROUTER_ALLOW_SKEW (30*60)

extern or_options_t options; /**< command-line and config-file options */

/** Do we need to regenerate the directory when someone asks for it? */
static int the_directory_is_dirty = 1;
static int runningrouters_is_dirty = 1;

static int list_running_servers(char **nicknames_out);
static void directory_remove_unrecognized(void);

/************** Fingerprint handling code ************/

typedef struct fingerprint_entry_t {
  char *nickname;
  char *fingerprint;
} fingerprint_entry_t;

/** List of nickname-\>identity fingerprint mappings for all the routers
 * that we recognize. Used to prevent Sybil attacks. */
static smartlist_t *fingerprint_list = NULL;

/** Add the fingerprint <b>fp</b> for the nickname <b>nickname</b> to
 * the global list of recognized identity key fingerprints.
 */
void /* Should be static; exposed for testing */
add_fingerprint_to_dir(const char *nickname, const char *fp)
{
  int i;
  fingerprint_entry_t *ent;
  if (!fingerprint_list)
    fingerprint_list = smartlist_create();

  for (i = 0; i < smartlist_len(fingerprint_list); ++i) {
    ent = smartlist_get(fingerprint_list, i);
    if (!strcasecmp(ent->nickname,nickname)) {
      tor_free(ent->fingerprint);
      ent->fingerprint = tor_strdup(fp);
      return;
    }
  }
  ent = tor_malloc(sizeof(fingerprint_entry_t));
  ent->nickname = tor_strdup(nickname);
  ent->fingerprint = tor_strdup(fp);
  smartlist_add(fingerprint_list, ent);
}

/** Add the nickname and fingerprint for this OR to the recognized list.
 */
int
dirserv_add_own_fingerprint(const char *nickname, crypto_pk_env_t *pk)
{
  char fp[FINGERPRINT_LEN+1];
  if (crypto_pk_get_fingerprint(pk, fp)<0) {
    log_fn(LOG_ERR, "Error computing fingerprint");
    return -1;
  }
  add_fingerprint_to_dir(nickname, fp);
  return 0;
}

/** Parse the nickname-\>fingerprint mappings stored in the file named
 * <b>fname</b>.  The file format is line-based, with each non-blank
 * holding one nickname, some space, and a fingerprint for that
 * nickname.  On success, replace the current fingerprint list with
 * the contents of <b>fname</b> and return 0.  On failure, leave the
 * current fingerprint list untouched, and return -1. */
int
dirserv_parse_fingerprint_file(const char *fname)
{
  FILE *file;
  char line[FINGERPRINT_LEN+MAX_NICKNAME_LEN+20+1];
  char *nickname, *fingerprint;
  smartlist_t *fingerprint_list_new;
  int i, result;
  fingerprint_entry_t *ent;

  if(!(file = fopen(fname, "r"))) {
    log_fn(LOG_WARN, "Cannot open fingerprint file %s", fname);
    return -1;
  }
  fingerprint_list_new = smartlist_create();
  while( (result=parse_line_from_file(line, sizeof(line),file,&nickname,&fingerprint)) > 0) {
    if (strlen(nickname) > MAX_NICKNAME_LEN) {
      log(LOG_WARN, "Nickname %s too long in fingerprint file. Skipping.", nickname);
      continue;
    }
    if(strlen(fingerprint) != FINGERPRINT_LEN ||
       !crypto_pk_check_fingerprint_syntax(fingerprint)) {
      log_fn(LOG_WARN, "Invalid fingerprint (nickname %s, fingerprint %s). Skipping.",
             nickname, fingerprint);
      continue;
    }
    for (i = 0; i < smartlist_len(fingerprint_list_new); ++i) {
      ent = smartlist_get(fingerprint_list_new, i);
      if (0==strcasecmp(ent->nickname, nickname)) {
        log(LOG_WARN, "Duplicate nickname %s. Skipping.",nickname);
        break; /* out of the for. the 'if' below means skip to the next line. */
      }
    }
    if(i == smartlist_len(fingerprint_list_new)) { /* not a duplicate */
      ent = tor_malloc(sizeof(fingerprint_entry_t));
      ent->nickname = tor_strdup(nickname);
      ent->fingerprint = tor_strdup(fingerprint);
      smartlist_add(fingerprint_list_new, ent);
    }
  }
  fclose(file);
  if(result == 0) { /* eof; replace the global fingerprints list. */
    dirserv_free_fingerprint_list();
    fingerprint_list = fingerprint_list_new;
    /* Delete any routers whose fingerprints we no longer recognize */
    directory_remove_unrecognized();
    return 0;
  }
  /* error */
  log_fn(LOG_WARN, "Error reading from fingerprint file");
  for (i = 0; i < smartlist_len(fingerprint_list_new); ++i) {
    ent = smartlist_get(fingerprint_list_new, i);
    tor_free(ent->nickname);
    tor_free(ent->fingerprint);
    tor_free(ent);
  }
  smartlist_free(fingerprint_list_new);
  return -1;
}

/** Check whether <b>router</b> has a nickname/identity key combination that
 * we recognize from the fingerprint list.  Return 1 if router's
 * identity and nickname match, -1 if we recognize the nickname but
 * the identity key is wrong, and 0 if the nickname is not known. */
int
dirserv_router_fingerprint_is_known(const routerinfo_t *router)
{
  int i, found=0;
  fingerprint_entry_t *ent =NULL;
  char fp[FINGERPRINT_LEN+1];

  if (!fingerprint_list)
    fingerprint_list = smartlist_create();

  log_fn(LOG_DEBUG, "%d fingerprints known.", smartlist_len(fingerprint_list));
  for (i=0;i<smartlist_len(fingerprint_list);++i) {
    ent = smartlist_get(fingerprint_list, i);
    log_fn(LOG_DEBUG,"%s vs %s", router->nickname, ent->nickname);
    if (!strcasecmp(router->nickname,ent->nickname)) {
      found = 1;
      break;
    }
  }

  if (!found) { /* No such server known */
    log_fn(LOG_INFO,"no fingerprint found for %s",router->nickname);
    return 0;
  }
  if (crypto_pk_get_fingerprint(router->identity_pkey, fp)) {
    log_fn(LOG_WARN,"error computing fingerprint");
    return -1;
  }
  if (0==strcasecmp(ent->fingerprint, fp)) {
    log_fn(LOG_DEBUG,"good fingerprint for %s",router->nickname);
    return 1; /* Right fingerprint. */
  } else {
    log_fn(LOG_WARN,"mismatched fingerprint for %s",router->nickname);
    return -1; /* Wrong fingerprint. */
  }
}

/** Return true iff any router named <b>nickname</b> with <b>digest</b>
 * is in the verified fingerprint list. */
static int
router_nickname_is_approved(const char *nickname, const char *digest)
{
  int i,j;
  fingerprint_entry_t *ent;
  char fp[FINGERPRINT_LEN+1];
  char hexdigest[HEX_DIGEST_LEN+1];
  if (!fingerprint_list)
    return 0;

  base16_encode(hexdigest, sizeof(hexdigest), digest, DIGEST_LEN);
  for (i=j=0;j<HEX_DIGEST_LEN;++i,++j) {
    fp[i]=hexdigest[j];
    if ((j%4)==3 && j != 39)
      fp[++i]=' ';
  }
  fp[i]='\0';

  for (i=0;i<smartlist_len(fingerprint_list);++i) {
    ent = smartlist_get(fingerprint_list, i);
    if (!strcasecmp(nickname,ent->nickname) &&
        !strcasecmp(fp,ent->fingerprint)) {
      return 1;
    }
  }
  return 0;
}

/** Clear the current fingerprint list. */
void
dirserv_free_fingerprint_list()
{
  int i;
  fingerprint_entry_t *ent;
  if (!fingerprint_list)
    return;

  for (i = 0; i < smartlist_len(fingerprint_list); ++i) {
    ent = smartlist_get(fingerprint_list, i);
    tor_free(ent->nickname);
    tor_free(ent->fingerprint);
    tor_free(ent);
  }
  smartlist_free(fingerprint_list);
  fingerprint_list = NULL;
}

/*
 *    Descriptor list
 */

/** A directory server's view of a server descriptor.  Contains both
 * parsed and unparsed versions. */
typedef struct descriptor_entry_t {
  char *nickname;
  time_t published;
  size_t desc_len;
  char *descriptor;
  int verified;
  routerinfo_t *router;
} descriptor_entry_t;

/** List of all server descriptors that this dirserv is holding. */
static smartlist_t *descriptor_list = NULL;

/** Release the storage held by <b>desc</b> */
static void free_descriptor_entry(descriptor_entry_t *desc)
{
  tor_free(desc->descriptor);
  tor_free(desc->nickname);
  routerinfo_free(desc->router);
  free(desc);
}

/** Release all storage that the dirserv is holding for server
 * descriptors. */
void
dirserv_free_descriptors()
{
  if (!descriptor_list)
    return;
  SMARTLIST_FOREACH(descriptor_list, descriptor_entry_t *, d,
                    free_descriptor_entry(d));
  smartlist_clear(descriptor_list);
}

/** Parse the server descriptor at *desc and maybe insert it into the
 * list of service descriptors, and (if the descriptor is well-formed)
 * advance *desc immediately past the descriptor's end.
 *
 * Return 1 if descriptor is well-formed and accepted;
 * 0 if well-formed and server is unapproved;
 * -1 if not well-formed or other error.
 */
int
dirserv_add_descriptor(const char **desc)
{
  descriptor_entry_t *ent = NULL;
  routerinfo_t *ri = NULL;
  int i, r, found=-1;
  char *start, *end;
  char *desc_tmp = NULL;
  const char *cp;
  size_t desc_len;
  time_t now;
  int verified=1; /* whether we knew its fingerprint already */

  if (!descriptor_list)
    descriptor_list = smartlist_create();

  start = strstr(*desc, "router ");
  if (!start) {
    log_fn(LOG_WARN, "no 'router' line found. This is not a descriptor.");
    return -1;
  }
  if ((end = strstr(start+6, "\nrouter "))) {
    ++end; /* Include NL. */
  } else if ((end = strstr(start+6, "\ndirectory-signature"))) {
    ++end;
  } else {
    end = start+strlen(start);
  }
  desc_len = end-start;
  cp = desc_tmp = tor_strndup(start, desc_len);

  /* Check: is the descriptor syntactically valid? */
  ri = router_parse_entry_from_string(cp, NULL);
  tor_free(desc_tmp);
  if (!ri) {
    log(LOG_WARN, "Couldn't parse descriptor");
    return -1;
  }
  /* Okay.  Now check whether the fingerprint is recognized. */
  r = dirserv_router_fingerprint_is_known(ri);
  if(r==-1) {
    log_fn(LOG_WARN, "Known nickname %s, wrong fingerprint. Not adding.", ri->nickname);
    routerinfo_free(ri);
    *desc = end;
    return 0;
  }
  if(r==0) {
    char fp[FINGERPRINT_LEN+1];
    log_fn(LOG_INFO, "Unknown nickname %s (%s:%d). Adding.",
           ri->nickname, ri->address, ri->or_port);
    if (crypto_pk_get_fingerprint(ri->identity_pkey, fp) < 0) {
      log_fn(LOG_WARN, "Error computing fingerprint for %s", ri->nickname);
    } else {
      log_fn(LOG_INFO, "Fingerprint line: %s %s", ri->nickname, fp);
    }
    verified = 0;
  }
  /* Is there too much clock skew? */
  now = time(NULL);
  if (ri->published_on > now+ROUTER_ALLOW_SKEW) {
    log_fn(LOG_WARN, "Publication time for nickname %s is too far in the future; possible clock skew. Not adding.", ri->nickname);
    routerinfo_free(ri);
    *desc = end;
    return 0;
  }
  if (ri->published_on < now-ROUTER_MAX_AGE) {
    log_fn(LOG_WARN, "Publication time for router with nickname %s is too far in the past. Not adding.", ri->nickname);
    routerinfo_free(ri);
    *desc = end;
    return 0;
  }

  /* Do we already have an entry for this router? */
  for (i = 0; i < smartlist_len(descriptor_list); ++i) {
    ent = smartlist_get(descriptor_list, i);
    if (!strcasecmp(ri->nickname, ent->nickname)) {
      found = i;
      break;
    }
  }
  if (found >= 0) {
    /* if so, decide whether to update it. */
    if (ent->published > ri->published_on) {
      /* We already have a newer descriptor */
      log_fn(LOG_INFO,"We already have a newer desc for nickname %s. Not adding.",ri->nickname);
      /* This isn't really an error; return success. */
      routerinfo_free(ri);
      *desc = end;
      return 1;
    }
    /* We don't have a newer one; we'll update this one. */
    log_fn(LOG_INFO,"Dirserv updating desc for nickname %s",ri->nickname);
    free_descriptor_entry(ent);
    smartlist_del_keeporder(descriptor_list, found);
  } else {
    /* Add at the end. */
    log_fn(LOG_INFO,"Dirserv adding desc for nickname %s",ri->nickname);
  }

  ent = tor_malloc(sizeof(descriptor_entry_t));
  ent->nickname = tor_strdup(ri->nickname);
  ent->published = ri->published_on;
  ent->desc_len = desc_len;
  ent->descriptor = tor_malloc(desc_len+1);
  strncpy(ent->descriptor, start, desc_len);
  ent->descriptor[desc_len] = '\0';
  ent->router = ri;
  /* XXX008 is ent->verified useful/used for anything? */
  ent->verified = verified; /* XXXX008 support other possibilities. */
  smartlist_add(descriptor_list, ent);

  *desc = end;
  directory_set_dirty();

  return 1;
}

/** Remove all descriptors whose nicknames or fingerprints we don't
 * recognize.  (Descriptors that used to be good can become
 * unrecognized when we reload the fingerprint list.)
 */
static void
directory_remove_unrecognized(void)
{
  int i;
  descriptor_entry_t *ent;
  if (!descriptor_list)
    descriptor_list = smartlist_create();

  for (i = 0; i < smartlist_len(descriptor_list); ++i) {
    ent = smartlist_get(descriptor_list, i);
    if (dirserv_router_fingerprint_is_known(ent->router)<=0) {
      log(LOG_INFO, "Router %s is no longer recognized",
          ent->nickname);
      free_descriptor_entry(ent);
      smartlist_del(descriptor_list, i--);
    }
  }
}

/** Mark the directory as <b>dirty</b> -- when we're next asked for a
 * directory, we will rebuild it instead of reusing the most recently
 * generated one.
 */
void
directory_set_dirty()
{
  the_directory_is_dirty = 1;
  runningrouters_is_dirty = 1;
}

/** Load all descriptors from a directory stored in the string
 * <b>dir</b>.
 */
int
dirserv_load_from_directory_string(const char *dir)
{
  const char *cp = dir;
  while(1) {
    cp = strstr(cp, "\nrouter ");
    if (!cp) break;
    ++cp;
    if (dirserv_add_descriptor(&cp) < 0) {
      return -1;
    }
    --cp; /*Back up to newline.*/
  }
  return 0;
}

/** Set *<b>nicknames_out</b> to a comma-separated list of all the ORs that we
 * believe are currently running (because we have open connections to
 * them).  Return 0 on success; -1 on error.
 */
static int
list_running_servers(char **nicknames_out)
{
  connection_t **connection_array;
  int n_conns;
  connection_t *conn;
  char *cp;
  int i;
  int length;
  smartlist_t *nicknames_up, *nicknames_down;

  *nicknames_out = NULL;
  nicknames_up = smartlist_create();
  nicknames_down = smartlist_create();
  smartlist_add(nicknames_up, tor_strdup(options.Nickname));

  get_connection_array(&connection_array, &n_conns);
  for (i = 0; i<n_conns; ++i) {
    char *name;
    conn = connection_array[i];
    if (conn->type != CONN_TYPE_OR || !conn->nickname)
      continue; /* only list ORs. */
    if (router_nickname_is_approved(conn->nickname, conn->identity_digest)) {
      name = tor_strdup(conn->nickname);
    } else {
      name = tor_malloc(HEX_DIGEST_LEN+2);
      *name = '$';
      base16_encode(name+1, HEX_DIGEST_LEN+1, conn->identity_digest, DIGEST_LEN);
    }

    if(conn->state == OR_CONN_STATE_OPEN)
      smartlist_add(nicknames_up, name);
    else
      smartlist_add(nicknames_down, name);
  }
  length = smartlist_len(nicknames_up) +
           2*smartlist_len(nicknames_down) + 1;
           /* spaces + EOS + !'s + 1. */
  SMARTLIST_FOREACH(nicknames_up, char *, c, length += strlen(c));
  SMARTLIST_FOREACH(nicknames_down, char *, c, length += strlen(c));
  *nicknames_out = tor_malloc_zero(length);
  cp = *nicknames_out;
  for (i = 0; i<smartlist_len(nicknames_up); ++i) {
    if (i)
      strcat(cp, " ");
    strcat(cp, (char*)smartlist_get(nicknames_up,i)); /* can't overflow */
    while (*cp)
      ++cp;
  }
  for (i = 0; i<smartlist_len(nicknames_down); ++i) {
    strcat(cp, " !");
    strcat(cp, (char*)smartlist_get(nicknames_down,i)); /* can't overflow */
    while (*cp)
      ++cp;
  }
  SMARTLIST_FOREACH(nicknames_up, char *, victim, tor_free(victim));
  SMARTLIST_FOREACH(nicknames_down, char *, victim, tor_free(victim));
  smartlist_free(nicknames_up);
  smartlist_free(nicknames_down);
  return 0;
}

/** Remove any descriptors from the directory that are more than ROUTER_MAX_AGE
 * seconds old.
 */
void
dirserv_remove_old_servers(void)
{
  int i;
  time_t cutoff;
  descriptor_entry_t *ent;
  if (!descriptor_list)
    descriptor_list = smartlist_create();

  cutoff = time(NULL) - ROUTER_MAX_AGE;
  for (i = 0; i < smartlist_len(descriptor_list); ++i) {
    ent = smartlist_get(descriptor_list, i);
    if (ent->published < cutoff) {
      /* descriptor_list[i] is too old.  Remove it. */
      free_descriptor_entry(ent);
      smartlist_del(descriptor_list, i--);
      directory_set_dirty();
    }
  }
}

/** Dump all routers currently in the directory into the string
 * <b>s</b>, using at most <b>maxlen</b> characters, and signing the
 * directory with <b>private_key</b>.  Return 0 on success, -1 on
 * failure.
 */
int
dirserv_dump_directory_to_string(char *s, unsigned int maxlen,
                                 crypto_pk_env_t *private_key)
{
  char *cp, *eos;
  char digest[20];
  char signature[128];
  char published[33];
  time_t published_on;
  int i;
  eos = s+maxlen;

  if (!descriptor_list)
    descriptor_list = smartlist_create();

  if (list_running_servers(&cp))
    return -1;
  dirserv_remove_old_servers();
  published_on = time(NULL);
  strftime(published, 32, "%Y-%m-%d %H:%M:%S", gmtime(&published_on));
  snprintf(s, maxlen,
           "signed-directory\n"
           "published %s\n"
           "recommended-software %s\n"
           "running-routers %s\n\n",
           published, options.RecommendedVersions, cp);

  free(cp);
  i = strlen(s);
  cp = s+i;

  SMARTLIST_FOREACH(descriptor_list, descriptor_entry_t *, d,
    if (strlcat(s, d->descriptor, maxlen) >= maxlen)
      goto truncated);

  /* These multiple strlcat calls are inefficient, but dwarfed by the RSA
     signature.
  */
  if (strlcat(s, "directory-signature ", maxlen) >= maxlen)
    goto truncated;
  if (strlcat(s, options.Nickname, maxlen) >= maxlen)
    goto truncated;
  if (strlcat(s, "\n", maxlen) >= maxlen)
    goto truncated;

  if (router_get_dir_hash(s,digest)) {
    log_fn(LOG_WARN,"couldn't compute digest");
    return -1;
  }
  if (crypto_pk_private_sign(private_key, digest, 20, signature) < 0) {
    log_fn(LOG_WARN,"couldn't sign digest");
    return -1;
  }
  log(LOG_DEBUG,"generated directory digest begins with %s",hex_str(digest,4));

  if (strlcat(cp, "-----BEGIN SIGNATURE-----\n", maxlen) >= maxlen)
    goto truncated;

  i = strlen(s);
  cp = s+i;
  if (base64_encode(cp, maxlen-i, signature, 128) < 0) {
    log_fn(LOG_WARN,"couldn't base64-encode signature");
    return -1;
  }
  
  if (strlcat(s, "-----END SIGNATURE-----\n", maxlen) >= maxlen)
    goto truncated;

  return 0;
 truncated:
  log_fn(LOG_WARN,"tried to exceed string length.");
  return -1;
}

/** Most recently generated encoded signed directory. */
static char *the_directory = NULL;
static int the_directory_len = -1;
static char *cached_directory = NULL; /* used only by non-auth dirservers */
static time_t cached_directory_published = 0;
static int cached_directory_len = -1;

void dirserv_set_cached_directory(const char *directory, time_t when)
{
  time_t now;
  tor_assert(!options.AuthoritativeDir);
  now = time(NULL);
  if (when>cached_directory_published &&
      when<now+ROUTER_ALLOW_SKEW) {
    tor_free(cached_directory);
    cached_directory = tor_strdup(directory);
    cached_directory_len = strlen(cached_directory);
    cached_directory_published = when;
  }
}

/** Set *<b>directory</b> to the most recently generated encoded signed
 * directory, generating a new one as necessary. */
size_t dirserv_get_directory(const char **directory)
{
  char *new_directory;
  char filename[512];
  if (!options.AuthoritativeDir) {
    if (cached_directory) {
      *directory = cached_directory;
      return (size_t) cached_directory_len;
    } else {
      /* no directory yet retrieved */
      return 0;
    }
  }
  if (the_directory_is_dirty) {
    new_directory = tor_malloc(MAX_DIR_SIZE);
    if (dirserv_dump_directory_to_string(new_directory, MAX_DIR_SIZE,
                                         get_identity_key())) {
      log(LOG_WARN, "Error creating directory.");
      free(new_directory);
      return 0;
    }
    tor_free(the_directory);
    the_directory = new_directory;
    the_directory_len = strlen(the_directory);
    log_fn(LOG_INFO,"New directory (size %d):\n%s",the_directory_len,
           the_directory);
    the_directory_is_dirty = 0;
    /* Now read the directory we just made in order to update our own
     * router lists.  This does more signature checking than is strictly
     * necessary, but safe is better than sorry. */
    new_directory = tor_strdup(the_directory);
    /* use a new copy of the dir, since get_dir_from_string scribbles on it */
    if (router_load_routerlist_from_directory(new_directory, get_identity_key())) {
      log_fn(LOG_ERR, "We just generated a directory we can't parse. Dying.");
      tor_cleanup();
      exit(0);
    }
    free(new_directory);
    if(get_data_directory(&options)) {
      sprintf(filename,"%s/cached-directory", get_data_directory(&options));
      if(write_str_to_file(filename,the_directory) < 0) {
        log_fn(LOG_WARN, "Couldn't write cached directory to disk. Ignoring.");
      }
    }
  } else {
    log(LOG_INFO,"Directory still clean, reusing.");
  }
  *directory = the_directory;
  return the_directory_len;
}

static char *runningrouters_string=NULL;
static size_t runningrouters_len=0;

/** Replace the current running-routers list with a newly generated one. */
static int generate_runningrouters(crypto_pk_env_t *private_key)
{
  char *s, *cp;
  char digest[DIGEST_LEN];
  char signature[PK_BYTES];
  int i, len;
  char published[33];
  time_t published_on;

  len = 1024+(MAX_HEX_NICKNAME_LEN+2)*smartlist_len(descriptor_list);
  s = tor_malloc_zero(len);
  if (list_running_servers(&cp))
    return -1;
  published_on = time(NULL);
  strftime(published, 32, "%Y-%m-%d %H:%M:%S", gmtime(&published_on));
  sprintf(s, "network-status\n"
             "published %s\n"
             "running-routers %s\n"
             "directory-signature %s\n"
             "-----BEGIN SIGNATURE-----\n",
             published, cp, options.Nickname);
  tor_free(cp);
  if (router_get_runningrouters_hash(s,digest)) {
    log_fn(LOG_WARN,"couldn't compute digest");
    return -1;
  }
  if (crypto_pk_private_sign(private_key, digest, 20, signature) < 0) {
    log_fn(LOG_WARN,"couldn't sign digest");
    return -1;
  }

  i = strlen(s);
  cp = s+i;
  if (base64_encode(cp, len-i, signature, 128) < 0) {
    log_fn(LOG_WARN,"couldn't base64-encode signature");
    return -1;
  }
  if (strlcat(s, "-----END SIGNATURE-----\n", len) >= len) {
    return -1;
  }

  tor_free(runningrouters_string);
  runningrouters_string = s;
  runningrouters_len = strlen(s);
  runningrouters_is_dirty = 0;
  return 0;
}

/** Set *<b>rr</b> to the most recently generated encoded signed
 * running-routers list, generating a new one as necessary. */
size_t dirserv_get_runningrouters(const char **rr)
{
  if (runningrouters_is_dirty) {
    if(generate_runningrouters(get_identity_key())) {
      log_fn(LOG_ERR, "Couldn't generate running-routers list?");
      return -1;
    }
  }
  *rr = runningrouters_string;
  return runningrouters_len;
}

/*
  Local Variables:
  mode:c
  indent-tabs-mode:nil
  c-basic-offset:2
  End:
*/