src/or/router.c

   1 /* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
   2 /* See LICENSE for licensing information */
   3 /* $Id$ */
   4
   5 #include "or.h"
   6
   7 /**
   8  * \file router.c
   9  * \brief OR functionality, including key maintenance, generating
  10  * and uploading server descriptors, retrying OR connections.
  11  **/
  12
  13 extern or_options_t options; /* command-line and config-file options */
  14
  15 /** Exposed for test.c. */ void get_platform_str(char *platform, int len);
  16
  17 /************************************************************/
  18
  19 /*****
  20  * Key management: ORs only.
  21  *****/
  22
  23 /** Private keys for this OR.  There is also an SSL key managed by tortls.c.
  24  */
  25 static tor_mutex_t *key_lock=NULL;
  26 static time_t onionkey_set_at=0; /* When was onionkey last changed? */
  27 static crypto_pk_env_t *onionkey=NULL;
  28 static crypto_pk_env_t *lastonionkey=NULL;
  29 static crypto_pk_env_t *identitykey=NULL;
  30
  31 /** Replace the current onion key with <b>k</b>.  Does not affect lastonionkey;
  32  * to update onionkey correctly, call rotate_onion_key().
  33  */
  34 void set_onion_key(crypto_pk_env_t *k) {
  35   tor_mutex_acquire(key_lock);
  36   onionkey = k;
  37   onionkey_set_at = time(NULL);
  38   tor_mutex_release(key_lock);
  39 }
  40
  41 /** Return the current onion key.  Requires that the onion key has been
  42  * loaded or generated. */
  43 crypto_pk_env_t *get_onion_key(void) {
  44   tor_assert(onionkey);
  45   return onionkey;
  46 }
  47
  48 /** Return the onion key that was current before the most recent onion
  49  * key rotation.  If no rotation has been performed since this process
  50  * started, return NULL.
  51  */
  52 crypto_pk_env_t *get_previous_onion_key(void) {
  53   return lastonionkey;
  54 }
  55
  56 void dup_onion_keys(crypto_pk_env_t **key, crypto_pk_env_t **last)
  57 {
  58   tor_assert(key && last);
  59   tor_mutex_acquire(key_lock);
  60   *key = crypto_pk_dup_key(onionkey);
  61   if (lastonionkey)
  62         *last = crypto_pk_dup_key(lastonionkey);
  63   else
  64     *last = NULL;
  65   tor_mutex_release(key_lock);
  66 }
  67
  68 /** Return the time when the onion key was last set.  This is either the time
  69  * when the process launched, or the time of the most recent key rotation since
  70  * the process launched.
  71  */
  72 time_t get_onion_key_set_at(void) {
  73   return onionkey_set_at;
  74 }
  75
  76 /** Set the current identity key to k.
  77  */
  78 void set_identity_key(crypto_pk_env_t *k) {
  79   identitykey = k;
  80 }
  81
  82 /** Returns the current identity key; requires that the identity key has been
  83  * set.
  84  */
  85 crypto_pk_env_t *get_identity_key(void) {
  86   tor_assert(identitykey);
  87   return identitykey;
  88 }
  89
  90 /** Replace the previous onion key with the current onion key, and generate
  91  * a new previous onion key.  Immediately after calling this function,
  92  * the OR should:
  93  *   - schedule all previous cpuworkers to shut down _after_ processing
  94  *     pending work.  (This will cause fresh cpuworkers to be generated.)
  95  *   - generate and upload a fresh routerinfo.
  96  */
  97 void rotate_onion_key(void)
  98 {
  99   char fname[512];
 100   crypto_pk_env_t *prkey;
 101   sprintf(fname,"%s/keys/onion.key",options.DataDirectory);
 102   if (!(prkey = crypto_new_pk_env())) {
 103     log(LOG_ERR, "Error creating crypto environment.");
 104     goto error;
 105   }
 106   if (crypto_pk_generate_key(prkey)) {
 107     log(LOG_ERR, "Error generating onion key");
 108     goto error;
 109   }
 110   if (crypto_pk_write_private_key_to_filename(prkey, fname)) {
 111     log(LOG_ERR, "Couldn't write generated key to %s.", fname);
 112     goto error;
 113   }
 114   tor_mutex_acquire(key_lock);
 115   if (lastonionkey)
 116     crypto_free_pk_env(lastonionkey);
 117   log_fn(LOG_INFO, "Rotating onion key");
 118   lastonionkey = onionkey;
 119   set_onion_key(prkey);
 120   tor_mutex_release(key_lock);
 121   return;
 122  error:
 123   log_fn(LOG_WARN, "Couldn't rotate onion key.");
 124 }
 125
 126 /** Try to read an RSA key from <b>fname</b>.  If <b>fname</b> doesn't exist,
 127  * create a new RSA key and save it in <b>fname</b>.  Return the read/created
 128  * key, or NULL on error.
 129  */
 130 crypto_pk_env_t *init_key_from_file(const char *fname)
 131 {
 132   crypto_pk_env_t *prkey = NULL;
 133   FILE *file = NULL;
 134
 135   if (!(prkey = crypto_new_pk_env())) {
 136     log(LOG_ERR, "Error creating crypto environment.");
 137     goto error;
 138   }
 139
 140   switch(file_status(fname)) {
 141   case FN_DIR:
 142   case FN_ERROR:
 143     log(LOG_ERR, "Can't read key from %s", fname);
 144     goto error;
 145   case FN_NOENT:
 146     log(LOG_INFO, "No key found in %s; generating fresh key.", fname);
 147     if (crypto_pk_generate_key(prkey)) {
 148       log(LOG_ERR, "Error generating onion key");
 149       goto error;
 150     }
 151     if (crypto_pk_check_key(prkey) <= 0) {
 152       log(LOG_ERR, "Generated key seems invalid");
 153       goto error;
 154     }
 155     log(LOG_INFO, "Generated key seems valid");
 156     if (crypto_pk_write_private_key_to_filename(prkey, fname)) {
 157       log(LOG_ERR, "Couldn't write generated key to %s.", fname);
 158       goto error;
 159     }
 160     return prkey;
 161   case FN_FILE:
 162     if (crypto_pk_read_private_key_from_filename(prkey, fname)) {
 163       log(LOG_ERR, "Error loading private key.");
 164       goto error;
 165     }
 166     return prkey;
 167   default:
 168     tor_assert(0);
 169   }
 170
 171  error:
 172   if (prkey)
 173     crypto_free_pk_env(prkey);
 174   if (file)
 175     fclose(file);
 176   return NULL;
 177 }
 178
 179 /** Initialize all OR private keys, and the TLS context, as necessary.
 180  * On OPs, this only initializes the tls context.
 181  */
 182 int init_keys(void) {
 183   char keydir[512];
 184   char fingerprint[FINGERPRINT_LEN+MAX_NICKNAME_LEN+3];
 185   char *cp;
 186   const char *tmp, *mydesc;
 187   crypto_pk_env_t *prkey;
 188
 189   if (!key_lock)
 190         key_lock = tor_mutex_new();
 191
 192   /* OP's don't need keys.  Just initialize the TLS context.*/
 193   if (!options.ORPort) {
 194     tor_assert(!options.DirPort);
 195     if (tor_tls_context_new(NULL, 0, NULL, 0)<0) {
 196       log_fn(LOG_ERR, "Error creating TLS context for OP.");
 197       return -1;
 198     }
 199     return 0;
 200   }
 201   /* Make sure DataDirectory exists, and is private. */
 202   tor_assert(options.DataDirectory);
 203   if (strlen(options.DataDirectory) > (512-128)) {
 204     log_fn(LOG_ERR, "DataDirectory is too long.");
 205     return -1;
 206   }
 207   if (check_private_dir(options.DataDirectory, 1)) {
 208     return -1;
 209   }
 210   /* Check the key directory. */
 211   sprintf(keydir,"%s/keys",options.DataDirectory);
 212   if (check_private_dir(keydir, 1)) {
 213     return -1;
 214   }
 215   cp = keydir + strlen(keydir); /* End of string. */
 216
 217   /* 1. Read identity key. Make it if none is found. */
 218   strcpy(cp, "/identity.key");
 219   log_fn(LOG_INFO,"Reading/making identity key %s...",keydir);
 220   prkey = init_key_from_file(keydir);
 221   if (!prkey) return -1;
 222   set_identity_key(prkey);
 223   /* 2. Read onion key.  Make it if none is found. */
 224   strcpy(cp, "/onion.key");
 225   log_fn(LOG_INFO,"Reading/making onion key %s...",keydir);
 226   prkey = init_key_from_file(keydir);
 227   if (!prkey) return -1;
 228   set_onion_key(prkey);
 229
 230   /* 3. Initialize link key and TLS context. */
 231   if (tor_tls_context_new(get_identity_key(), 1, options.Nickname,
 232                           MAX_SSL_KEY_LIFETIME) < 0) {
 233     log_fn(LOG_ERR, "Error initializing TLS context");
 234     return -1;
 235   }
 236   /* 4. Dump router descriptor to 'router.desc' */
 237   /* Must be called after keys are initialized. */
 238   if (!(router_get_my_descriptor())) {
 239     log_fn(LOG_ERR, "Error initializing descriptor.");
 240     return -1;
 241   }
 242   /* We need to add our own fingerprint so it gets recognized. */
 243   if (dirserv_add_own_fingerprint(options.Nickname, get_identity_key())) {
 244     log_fn(LOG_ERR, "Error adding own fingerprint to approved set");
 245     return -1;
 246   }
 247   tmp = mydesc = router_get_my_descriptor();
 248   if (dirserv_add_descriptor(&tmp) != 1) {
 249     log(LOG_ERR, "Unable to add own descriptor to directory.");
 250     return -1;
 251   }
 252   sprintf(keydir,"%s/router.desc", options.DataDirectory);
 253   log_fn(LOG_INFO,"Dumping descriptor to %s...",keydir);
 254   if (write_str_to_file(keydir, mydesc)) {
 255     return -1;
 256   }
 257   /* 5. Dump fingerprint to 'fingerprint' */
 258   sprintf(keydir,"%s/fingerprint", options.DataDirectory);
 259   log_fn(LOG_INFO,"Dumping fingerprint to %s...",keydir);
 260   tor_assert(strlen(options.Nickname) <= MAX_NICKNAME_LEN);
 261   strcpy(fingerprint, options.Nickname);
 262   strcat(fingerprint, " ");
 263   if (crypto_pk_get_fingerprint(get_identity_key(),
 264                                 fingerprint+strlen(fingerprint))<0) {
 265     log_fn(LOG_ERR, "Error computing fingerprint");
 266     return -1;
 267   }
 268   strcat(fingerprint, "\n");
 269   if (write_str_to_file(keydir, fingerprint))
 270     return -1;
 271   if(!options.DirPort)
 272     return 0;
 273   /* 6. [dirserver only] load approved-routers file */
 274   sprintf(keydir,"%s/approved-routers", options.DataDirectory);
 275   log_fn(LOG_INFO,"Loading approved fingerprints from %s...",keydir);
 276   if(dirserv_parse_fingerprint_file(keydir) < 0) {
 277     log_fn(LOG_ERR, "Error loading fingerprints");
 278     return -1;
 279   }
 280   /* 7. [dirserver only] load old directory, if it's there */
 281   sprintf(keydir,"%s/cached-directory", options.DataDirectory);
 282   log_fn(LOG_INFO,"Loading cached directory from %s...",keydir);
 283   cp = read_file_to_str(keydir);
 284   if(!cp) {
 285     log_fn(LOG_INFO,"Cached directory %s not present. Ok.",keydir);
 286   } else {
 287     if(dirserv_init_from_directory_string(cp) < 0) {
 288       log_fn(LOG_ERR, "Cached directory %s is corrupt", keydir);
 289       free(cp);
 290       return -1;
 291     }
 292     free(cp);
 293   }
 294   /* success */
 295   return 0;
 296 }
 297
 298 /*
 299  * Clique maintenance
 300  */
 301
 302 /** OR only: try to open connections to all of the other ORs we know about.
 303  */
 304 void router_retry_connections(void) {
 305   int i;
 306   routerinfo_t *router;
 307   routerlist_t *rl;
 308
 309   router_get_routerlist(&rl);
 310   for (i=0;i < smartlist_len(rl->routers);i++) {
 311     router = smartlist_get(rl->routers, i);
 312     if(router_is_me(router))
 313       continue;
 314     if(!connection_exact_get_by_addr_port(router->addr,router->or_port)) {
 315       /* not in the list */
 316       log_fn(LOG_DEBUG,"connecting to OR %s:%u.",router->address,router->or_port);
 317       connection_or_connect(router);
 318     }
 319   }
 320 }
 321
 322 /*
 323  * OR descriptor generation.
 324  */
 325
 326 /** My routerinfo. */
 327 static routerinfo_t *desc_routerinfo = NULL;
 328 /** String representation of my descriptor, signed by me. */
 329 static char descriptor[8192];
 330
 331 /** OR only: try to upload our signed descriptor to all the directory servers
 332  * we know about.
 333  */
 334 void router_upload_dir_desc_to_dirservers(void) {
 335   const char *s;
 336
 337   s = router_get_my_descriptor();
 338   if (!s) {
 339     log_fn(LOG_WARN, "No descriptor; skipping upload");
 340     return;
 341   }
 342   directory_post_to_dirservers(DIR_PURPOSE_UPLOAD_DIR, s, strlen(s));
 343 }
 344
 345 #define DEFAULT_EXIT_POLICY "reject 0.0.0.0/8,reject 169.254.0.0/16,reject 127.0.0.0/8,reject 192.168.0.0/16,reject 10.0.0.0/8,reject 172.16.0.0/12,accept *:20-22,accept *:53,accept *:79-81,accept *:110,accept *:143,accept *:443,accept *:873,accept *:993,accept *:995,accept *:1024-65535,reject *:*"
 346
 347 /** Set the exit policy on <b>router</b> to match the exit policy in the
 348  * current configuration file.  If the exit policy doesn't have a catch-all
 349  * rule, then append the default exit policy as well.
 350  */
 351 static void router_add_exit_policy_from_config(routerinfo_t *router) {
 352   struct exit_policy_t *ep;
 353   struct config_line_t default_policy;
 354   config_parse_exit_policy(options.ExitPolicy, &router->exit_policy);
 355
 356   for (ep = router->exit_policy; ep; ep = ep->next) {
 357     if (ep->msk == 0 && ep->prt_min <= 1 && ep->prt_max >= 65535) {
 358       /* if exitpolicy includes a *:* line, then we're done. */
 359       return;
 360     }
 361   }
 362
 363   /* Else, append the default exitpolicy. */
 364   default_policy.key = NULL;
 365   default_policy.value = DEFAULT_EXIT_POLICY;
 366   default_policy.next = NULL;
 367   config_parse_exit_policy(&default_policy, &router->exit_policy);
 368 }
 369
 370 /** OR only: Return false if my exit policy says to allow connection to
 371  * conn.  Else return true.
 372  */
 373 int router_compare_to_my_exit_policy(connection_t *conn)
 374 {
 375   tor_assert(desc_routerinfo);
 376   tor_assert(conn->addr); /* make sure it's resolved to something. this
 377                              way we can't get a 'maybe' below. */
 378
 379   return router_compare_addr_to_exit_policy(conn->addr, conn->port,
 380                    desc_routerinfo->exit_policy);
 381
 382 }
 383
 384 /** Return true iff <b>router</b> has the same nickname as this OR.  (For an
 385  * OP, always returns false.)
 386  */
 387 int router_is_me(routerinfo_t *router)
 388 {
 389   tor_assert(router);
 390   return options.Nickname && !strcasecmp(router->nickname, options.Nickname);
 391 }
 392
 393 /** Return a routerinfo for this OR, rebuilding a fresh one if
 394  * necessary.  Return NULL on error, or if called on an OP. */
 395 routerinfo_t *router_get_my_routerinfo(void)
 396 {
 397   if (!options.ORPort)
 398     return NULL;
 399
 400   if (!desc_routerinfo) {
 401     if (router_rebuild_descriptor())
 402       return NULL;
 403   }
 404   return desc_routerinfo;
 405 }
 406
 407 /** OR only: Return a signed server descriptor for this OR, rebuilding a fresh
 408  * one if necessary.  Return NULL on error.
 409  */
 410 const char *router_get_my_descriptor(void) {
 411   if (!desc_routerinfo) {
 412     if (router_rebuild_descriptor())
 413       return NULL;
 414   }
 415   log_fn(LOG_DEBUG,"my desc is '%s'",descriptor);
 416   return descriptor;
 417 }
 418
 419 /** Rebuild a fresh routerinfo and signed server descriptor for this
 420  * OR.  Return 0 on success, -1 on error.
 421  */
 422 int router_rebuild_descriptor(void) {
 423   routerinfo_t *ri;
 424   struct in_addr addr;
 425   char platform[256];
 426   if (!tor_inet_aton(options.Address, &addr)) {
 427     log_fn(LOG_ERR, "options.Address didn't hold an IP.");
 428     return -1;
 429   }
 430
 431   ri = tor_malloc_zero(sizeof(routerinfo_t));
 432   ri->address = tor_strdup(options.Address);
 433   ri->nickname = tor_strdup(options.Nickname);
 434   ri->addr = (uint32_t) ntohl(addr.s_addr);
 435   ri->or_port = options.ORPort;
 436   ri->socks_port = options.SocksPort;
 437   ri->dir_port = options.DirPort;
 438   ri->published_on = time(NULL);
 439   ri->onion_pkey = crypto_pk_dup_key(get_onion_key()); /* must invoke from main thread */
 440   ri->identity_pkey = crypto_pk_dup_key(get_identity_key());
 441   get_platform_str(platform, sizeof(platform));
 442   ri->platform = tor_strdup(platform);
 443   ri->bandwidthrate = options.BandwidthRate;
 444   ri->bandwidthburst = options.BandwidthBurst;
 445   ri->exit_policy = NULL; /* zero it out first */
 446   router_add_exit_policy_from_config(ri);
 447   if (desc_routerinfo)
 448     routerinfo_free(desc_routerinfo);
 449   desc_routerinfo = ri;
 450   if (router_dump_router_to_string(descriptor, 8192, ri, get_identity_key())<0) {
 451     log_fn(LOG_WARN, "Couldn't dump router to string.");
 452     return -1;
 453   }
 454   if (ri->dir_port)
 455     ri->is_trusted_dir = 1;
 456   return 0;
 457 }
 458
 459 /** Set <b>platform</b> (max length <b>len</b>) to a NUL-terminated short
 460  * string describing the version of Tor and the operating system we're
 461  * currently running on.
 462  */
 463 void get_platform_str(char *platform, int len)
 464 {
 465   snprintf(platform, len-1, "Tor %s on %s", VERSION, get_uname());
 466   platform[len-1] = '\0';
 467   return;
 468 }
 469
 470 /* XXX need to audit this thing and count fenceposts. maybe
 471  *     refactor so we don't have to keep asking if we're
 472  *     near the end of maxlen?
 473  */
 474 #define DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
 475
 476 /** OR only: Given a routerinfo for this router, and an identity key to sign
 477  * with, encode the routerinfo as a signed server descriptor and write the
 478  * result into <b>s</b>, using at most <b>maxlen</b> bytes.  Return -1 on
 479  * failure, and the number of bytes used on success.
 480  */
 481 int router_dump_router_to_string(char *s, int maxlen, routerinfo_t *router,
 482                                  crypto_pk_env_t *ident_key) {
 483   char *onion_pkey; /* Onion key, PEM-encoded. */
 484   char *identity_pkey; /* Identity key, PEM-encoded. */
 485   char digest[20];
 486   char signature[128];
 487   char published[32];
 488   struct in_addr in;
 489   int onion_pkeylen, identity_pkeylen;
 490   int written;
 491   int result=0;
 492   struct exit_policy_t *tmpe;
 493 #ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
 494   char *s_tmp, *s_dup;
 495   const char *cp;
 496   routerinfo_t *ri_tmp;
 497 #endif
 498
 499   /* Make sure the identity key matches the one in the routerinfo. */
 500   if (crypto_pk_cmp_keys(ident_key, router->identity_pkey)) {
 501     log_fn(LOG_WARN,"Tried to sign a router with a private key that didn't match router's public key!");
 502     return -1;
 503   }
 504
 505   /* PEM-encode the onion key */
 506   if(crypto_pk_write_public_key_to_string(router->onion_pkey,
 507                                           &onion_pkey,&onion_pkeylen)<0) {
 508     log_fn(LOG_WARN,"write onion_pkey to string failed!");
 509     return -1;
 510   }
 511
 512   /* PEM-encode the identity key key */
 513   if(crypto_pk_write_public_key_to_string(router->identity_pkey,
 514                                           &identity_pkey,&identity_pkeylen)<0) {
 515     log_fn(LOG_WARN,"write identity_pkey to string failed!");
 516     tor_free(onion_pkey);
 517     return -1;
 518   }
 519
 520   /* Encode the publication time. */
 521   strftime(published, 32, "%Y-%m-%d %H:%M:%S", gmtime(&router->published_on));
 522
 523   /* Generate the easy portion of the router descriptor. */
 524   result = snprintf(s, maxlen,
 525                     "router %s %s %d %d %d\n"
 526                     "platform %s\n"
 527                     "published %s\n"
 528                     "bandwidth %d %d\n"
 529                     "onion-key\n%s"
 530                     "signing-key\n%s",
 531     router->nickname,
 532     router->address,
 533     router->or_port,
 534     router->socks_port,
 535     router->dir_port,
 536     router->platform,
 537     published,
 538     (int) router->bandwidthrate,
 539     (int) router->bandwidthburst,
 540     onion_pkey, identity_pkey);
 541
 542   tor_free(onion_pkey);
 543   tor_free(identity_pkey);
 544
 545   if(result < 0 || result >= maxlen) {
 546     /* apparently different glibcs do different things on snprintf error.. so check both */
 547     return -1;
 548   }
 549   /* From now on, we use 'written' to remember the current length of 's'. */
 550   written = result;
 551
 552   /* Write the exit policy to the end of 's'. */
 553   for(tmpe=router->exit_policy; tmpe; tmpe=tmpe->next) {
 554     in.s_addr = htonl(tmpe->addr);
 555     /* Write: "accept 1.2.3.4" */
 556     result = snprintf(s+written, maxlen-written, "%s %s",
 557         tmpe->policy_type == EXIT_POLICY_ACCEPT ? "accept" : "reject",
 558         tmpe->msk == 0 ? "*" : inet_ntoa(in));
 559     if(result < 0 || result+written > maxlen) {
 560       /* apparently different glibcs do different things on snprintf error.. so check both */
 561       return -1;
 562     }
 563     written += result;
 564     if (tmpe->msk != 0xFFFFFFFFu && tmpe->msk != 0) {
 565       /* Write "/255.255.0.0" */
 566       in.s_addr = htonl(tmpe->msk);
 567       result = snprintf(s+written, maxlen-written, "/%s", inet_ntoa(in));
 568       if (result<0 || result+written > maxlen)
 569         return -1;
 570       written += result;
 571     }
 572     if (tmpe->prt_min == 0 && tmpe->prt_max == 65535) {
 573       /* There is no port set; write ":*" */
 574       if (written > maxlen-4)
 575         return -1;
 576       strcat(s+written, ":*\n");
 577       written += 3;
 578     } else if (tmpe->prt_min == tmpe->prt_max) {
 579       /* There is only one port; write ":80". */
 580       result = snprintf(s+written, maxlen-written, ":%d\n", tmpe->prt_min);
 581       if (result<0 || result+written > maxlen)
 582         return -1;
 583       written += result;
 584     } else {
 585       /* There is a range of ports; write ":79-80". */
 586       result = snprintf(s+written, maxlen-written, ":%d-%d\n", tmpe->prt_min,
 587                         tmpe->prt_max);
 588       if (result<0 || result+written > maxlen)
 589         return -1;
 590       written += result;
 591     }
 592   } /* end for */
 593   if (written > maxlen-256) /* Not enough room for signature. */
 594     return -1;
 595
 596   /* Sign the directory */
 597   strcat(s+written, "router-signature\n");
 598   written += strlen(s+written);
 599   s[written] = '\0';
 600   if (router_get_router_hash(s, digest) < 0)
 601     return -1;
 602
 603   if (crypto_pk_private_sign(ident_key, digest, 20, signature) < 0) {
 604     log_fn(LOG_WARN, "Error signing digest");
 605     return -1;
 606   }
 607   strcat(s+written, "-----BEGIN SIGNATURE-----\n");
 608   written += strlen(s+written);
 609   if (base64_encode(s+written, maxlen-written, signature, 128) < 0) {
 610     log_fn(LOG_WARN, "Couldn't base64-encode signature");
 611     return -1;
 612   }
 613   written += strlen(s+written);
 614   strcat(s+written, "-----END SIGNATURE-----\n");
 615   written += strlen(s+written);
 616
 617   if (written > maxlen-2)
 618     return -1;
 619   /* include a last '\n' */
 620   s[written] = '\n';
 621   s[written+1] = 0;
 622
 623 #ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
 624   cp = s_tmp = s_dup = tor_strdup(s);
 625   ri_tmp = router_parse_entry_from_string(cp, NULL);
 626   if (!ri_tmp) {
 627     log_fn(LOG_ERR, "We just generated a router descriptor we can't parse: <<%s>>",
 628            s);
 629     return -1;
 630   }
 631   free(s_dup);
 632   routerinfo_free(ri_tmp);
 633 #endif
 634
 635   return written+1;
 636 }
 637
 638 /*
 639   Local Variables:
 640   mode:c
 641   indent-tabs-mode:nil
 642   c-basic-offset:2
 643   End:
 644 */