1 /* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
2 * Copyright (c) 2007-2009, The Tor Project, Inc. */
3 /* See LICENSE for licensing information */
7 * \brief Client code to access location-hidden services.
12 /** Called when we've established a circuit to an introduction point:
13 * send the introduction request. */
15 rend_client_introcirc_has_opened(origin_circuit_t
*circ
)
17 tor_assert(circ
->_base
.purpose
== CIRCUIT_PURPOSE_C_INTRODUCING
);
18 tor_assert(circ
->cpath
);
20 log_info(LD_REND
,"introcirc is open");
21 connection_ap_attach_pending();
24 /** Send the establish-rendezvous cell along a rendezvous circuit. if
25 * it fails, mark the circ for close and return -1. else return 0.
28 rend_client_send_establish_rendezvous(origin_circuit_t
*circ
)
30 tor_assert(circ
->_base
.purpose
== CIRCUIT_PURPOSE_C_ESTABLISH_REND
);
31 tor_assert(circ
->rend_data
);
32 log_info(LD_REND
, "Sending an ESTABLISH_RENDEZVOUS cell");
34 if (crypto_rand(circ
->rend_data
->rend_cookie
, REND_COOKIE_LEN
) < 0) {
35 log_warn(LD_BUG
, "Internal error: Couldn't produce random cookie.");
36 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_INTERNAL
);
39 if (relay_send_command_from_edge(0, TO_CIRCUIT(circ
),
40 RELAY_COMMAND_ESTABLISH_RENDEZVOUS
,
41 circ
->rend_data
->rend_cookie
,
43 circ
->cpath
->prev
)<0) {
44 /* circ is already marked for close */
45 log_warn(LD_GENERAL
, "Couldn't send ESTABLISH_RENDEZVOUS cell");
52 /** Called when we're trying to connect an ap conn; sends an INTRODUCE1 cell
53 * down introcirc if possible.
56 rend_client_send_introduction(origin_circuit_t
*introcirc
,
57 origin_circuit_t
*rendcirc
)
61 char payload
[RELAY_PAYLOAD_SIZE
];
62 char tmp
[RELAY_PAYLOAD_SIZE
];
63 rend_cache_entry_t
*entry
;
66 crypto_pk_env_t
*intro_key
; /* either Bob's public key or an intro key. */
68 tor_assert(introcirc
->_base
.purpose
== CIRCUIT_PURPOSE_C_INTRODUCING
);
69 tor_assert(rendcirc
->_base
.purpose
== CIRCUIT_PURPOSE_C_REND_READY
);
70 tor_assert(introcirc
->rend_data
);
71 tor_assert(rendcirc
->rend_data
);
72 tor_assert(!rend_cmp_service_ids(introcirc
->rend_data
->onion_address
,
73 rendcirc
->rend_data
->onion_address
));
75 if (rend_cache_lookup_entry(introcirc
->rend_data
->onion_address
, -1,
78 "query %s didn't have valid rend desc in cache. Failing.",
79 escaped_safe_str(introcirc
->rend_data
->onion_address
));
83 /* first 20 bytes of payload are the hash of Bob's pk */
84 if (entry
->parsed
->version
== 0) { /* un-versioned descriptor */
85 intro_key
= entry
->parsed
->pk
;
86 } else { /* versioned descriptor */
88 SMARTLIST_FOREACH(entry
->parsed
->intro_nodes
, rend_intro_point_t
*,
90 if (!memcmp(introcirc
->build_state
->chosen_exit
->identity_digest
,
91 intro
->extend_info
->identity_digest
, DIGEST_LEN
)) {
92 intro_key
= intro
->intro_key
;
97 log_warn(LD_BUG
, "Internal error: could not find intro key.");
101 if (crypto_pk_get_digest(intro_key
, payload
)<0) {
102 log_warn(LD_BUG
, "Internal error: couldn't hash public key.");
106 /* Initialize the pending_final_cpath and start the DH handshake. */
107 cpath
= rendcirc
->build_state
->pending_final_cpath
;
109 cpath
= rendcirc
->build_state
->pending_final_cpath
=
110 tor_malloc_zero(sizeof(crypt_path_t
));
111 cpath
->magic
= CRYPT_PATH_MAGIC
;
112 if (!(cpath
->dh_handshake_state
= crypto_dh_new())) {
113 log_warn(LD_BUG
, "Internal error: couldn't allocate DH.");
116 if (crypto_dh_generate_public(cpath
->dh_handshake_state
)<0) {
117 log_warn(LD_BUG
, "Internal error: couldn't generate g^x.");
122 /* If version is 3, write (optional) auth data and timestamp. */
123 if (entry
->parsed
->protocols
& (1<<3)) {
124 tmp
[0] = 3; /* version 3 of the cell format */
125 tmp
[1] = (uint8_t)introcirc
->rend_data
->auth_type
; /* auth type, if any */
127 if (introcirc
->rend_data
->auth_type
!= REND_NO_AUTH
) {
128 set_uint16(tmp
+2, htons(REND_DESC_COOKIE_LEN
));
129 memcpy(tmp
+4, introcirc
->rend_data
->descriptor_cookie
,
130 REND_DESC_COOKIE_LEN
);
131 v3_shift
+= 2+REND_DESC_COOKIE_LEN
;
133 set_uint32(tmp
+v3_shift
+1, htonl(time(NULL
)));
135 } /* if version 2 only write version number */
136 else if (entry
->parsed
->protocols
& (1<<2)) {
137 tmp
[0] = 2; /* version 2 of the cell format */
140 /* write the remaining items into tmp */
141 if (entry
->parsed
->protocols
& (1<<3) || entry
->parsed
->protocols
& (1<<2)) {
142 /* version 2 format */
143 extend_info_t
*extend_info
= rendcirc
->build_state
->chosen_exit
;
146 set_uint32(tmp
+v3_shift
+1, tor_addr_to_ipv4h(&extend_info
->addr
));
147 set_uint16(tmp
+v3_shift
+5, htons(extend_info
->port
));
148 memcpy(tmp
+v3_shift
+7, extend_info
->identity_digest
, DIGEST_LEN
);
149 klen
= crypto_pk_asn1_encode(extend_info
->onion_key
,
150 tmp
+v3_shift
+7+DIGEST_LEN
+2,
151 sizeof(tmp
)-(v3_shift
+7+DIGEST_LEN
+2));
152 set_uint16(tmp
+v3_shift
+7+DIGEST_LEN
, htons(klen
));
153 memcpy(tmp
+v3_shift
+7+DIGEST_LEN
+2+klen
, rendcirc
->rend_data
->rend_cookie
,
155 dh_offset
= v3_shift
+7+DIGEST_LEN
+2+klen
+REND_COOKIE_LEN
;
158 strncpy(tmp
, rendcirc
->build_state
->chosen_exit
->nickname
,
159 (MAX_NICKNAME_LEN
+1)); /* nul pads */
160 memcpy(tmp
+MAX_NICKNAME_LEN
+1, rendcirc
->rend_data
->rend_cookie
,
162 dh_offset
= MAX_NICKNAME_LEN
+1+REND_COOKIE_LEN
;
165 if (crypto_dh_get_public(cpath
->dh_handshake_state
, tmp
+dh_offset
,
167 log_warn(LD_BUG
, "Internal error: couldn't extract g^x.");
171 note_crypto_pk_op(REND_CLIENT
);
172 /*XXX maybe give crypto_pk_public_hybrid_encrypt a max_len arg,
173 * to avoid buffer overflows? */
174 r
= crypto_pk_public_hybrid_encrypt(intro_key
, payload
+DIGEST_LEN
,
176 (int)(dh_offset
+DH_KEY_LEN
),
177 PK_PKCS1_OAEP_PADDING
, 0);
179 log_warn(LD_BUG
,"Internal error: hybrid pk encrypt failed.");
183 payload_len
= DIGEST_LEN
+ r
;
184 tor_assert(payload_len
<= RELAY_PAYLOAD_SIZE
); /* we overran something */
186 log_info(LD_REND
, "Sending an INTRODUCE1 cell");
187 if (relay_send_command_from_edge(0, TO_CIRCUIT(introcirc
),
188 RELAY_COMMAND_INTRODUCE1
,
189 payload
, payload_len
,
190 introcirc
->cpath
->prev
)<0) {
191 /* introcirc is already marked for close. leave rendcirc alone. */
192 log_warn(LD_BUG
, "Couldn't send INTRODUCE1 cell");
196 /* Now, we wait for an ACK or NAK on this circuit. */
197 introcirc
->_base
.purpose
= CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT
;
201 circuit_mark_for_close(TO_CIRCUIT(introcirc
), END_CIRC_REASON_INTERNAL
);
202 circuit_mark_for_close(TO_CIRCUIT(rendcirc
), END_CIRC_REASON_INTERNAL
);
206 /** Called when a rendezvous circuit is open; sends a establish
207 * rendezvous circuit as appropriate. */
209 rend_client_rendcirc_has_opened(origin_circuit_t
*circ
)
211 tor_assert(circ
->_base
.purpose
== CIRCUIT_PURPOSE_C_ESTABLISH_REND
);
213 log_info(LD_REND
,"rendcirc is open");
215 /* generate a rendezvous cookie, store it in circ */
216 if (rend_client_send_establish_rendezvous(circ
) < 0) {
221 /** Called when get an ACK or a NAK for a REND_INTRODUCE1 cell.
224 rend_client_introduction_acked(origin_circuit_t
*circ
,
225 const char *request
, size_t request_len
)
227 origin_circuit_t
*rendcirc
;
228 (void) request
; // XXXX Use this.
230 if (circ
->_base
.purpose
!= CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT
) {
231 log_warn(LD_PROTOCOL
,
232 "Received REND_INTRODUCE_ACK on unexpected circuit %d.",
233 circ
->_base
.n_circ_id
);
234 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_TORPROTOCOL
);
238 tor_assert(circ
->build_state
->chosen_exit
);
239 tor_assert(circ
->rend_data
);
241 if (request_len
== 0) {
242 /* It's an ACK; the introduction point relayed our introduction request. */
243 /* Locate the rend circ which is waiting to hear about this ack,
246 log_info(LD_REND
,"Received ack. Telling rend circ...");
247 rendcirc
= circuit_get_by_rend_query_and_purpose(
248 circ
->rend_data
->onion_address
, CIRCUIT_PURPOSE_C_REND_READY
);
249 if (rendcirc
) { /* remember the ack */
250 rendcirc
->_base
.purpose
= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED
;
252 log_info(LD_REND
,"...Found no rend circ. Dropping on the floor.");
254 /* close the circuit: we won't need it anymore. */
255 circ
->_base
.purpose
= CIRCUIT_PURPOSE_C_INTRODUCE_ACKED
;
256 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_FINISHED
);
258 /* It's a NAK; the introduction point didn't relay our request. */
259 circ
->_base
.purpose
= CIRCUIT_PURPOSE_C_INTRODUCING
;
260 /* Remove this intro point from the set of viable introduction
261 * points. If any remain, extend to a new one and try again.
262 * If none remain, refetch the service descriptor.
264 if (rend_client_remove_intro_point(circ
->build_state
->chosen_exit
,
265 circ
->rend_data
) > 0) {
266 /* There are introduction points left. Re-extend the circuit to
267 * another intro point and try again. */
268 extend_info_t
*extend_info
;
270 extend_info
= rend_client_get_random_intro(circ
->rend_data
);
272 log_warn(LD_REND
, "No introduction points left for %s. Closing.",
273 escaped_safe_str(circ
->rend_data
->onion_address
));
274 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_INTERNAL
);
277 if (circ
->remaining_relay_early_cells
) {
279 "Got nack for %s from %s. Re-extending circ %d, "
281 escaped_safe_str(circ
->rend_data
->onion_address
),
282 circ
->build_state
->chosen_exit
->nickname
,
283 circ
->_base
.n_circ_id
, extend_info
->nickname
);
284 result
= circuit_extend_to_new_exit(circ
, extend_info
);
287 "Got nack for %s from %s. Building a new introduction "
288 "circuit, this time to %s.",
289 escaped_safe_str(circ
->rend_data
->onion_address
),
290 circ
->build_state
->chosen_exit
->nickname
,
291 extend_info
->nickname
);
292 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_FINISHED
);
293 if (!circuit_launch_by_extend_info(CIRCUIT_PURPOSE_C_INTRODUCING
,
295 CIRCLAUNCH_IS_INTERNAL
)) {
296 log_warn(LD_REND
, "Building introduction circuit failed.");
302 extend_info_free(extend_info
);
309 /** The period for which a hidden service directory cannot be queried for
310 * the same descriptor ID again. */
311 #define REND_HID_SERV_DIR_REQUERY_PERIOD (15 * 60)
313 /** Contains the last request times to hidden service directories for
314 * certain queries; keys are strings consisting of base32-encoded
315 * hidden service directory identities and base32-encoded descriptor IDs;
316 * values are pointers to timestamps of the last requests. */
317 static strmap_t
*last_hid_serv_requests
= NULL
;
319 /** Look up the last request time to hidden service directory <b>hs_dir</b>
320 * for descriptor ID <b>desc_id_base32</b>. If <b>set</b> is non-zero,
321 * assign the current time <b>now</b> and return that. Otherwise, return
322 * the most recent request time, or 0 if no such request has been sent
325 lookup_last_hid_serv_request(routerstatus_t
*hs_dir
,
326 const char *desc_id_base32
, time_t now
, int set
)
328 char hsdir_id_base32
[REND_DESC_ID_V2_LEN_BASE32
+ 1];
329 char hsdir_desc_comb_id
[2 * REND_DESC_ID_V2_LEN_BASE32
+ 1];
330 time_t *last_request_ptr
;
331 base32_encode(hsdir_id_base32
, sizeof(hsdir_id_base32
),
332 hs_dir
->identity_digest
, DIGEST_LEN
);
333 tor_snprintf(hsdir_desc_comb_id
, sizeof(hsdir_desc_comb_id
), "%s%s",
334 hsdir_id_base32
, desc_id_base32
);
336 last_request_ptr
= tor_malloc_zero(sizeof(time_t *));
337 *last_request_ptr
= now
;
338 strmap_set(last_hid_serv_requests
, hsdir_desc_comb_id
, last_request_ptr
);
340 last_request_ptr
= strmap_get_lc(last_hid_serv_requests
,
342 return (last_request_ptr
) ? *last_request_ptr
: 0;
345 /** Clean the history of request times to hidden service directories, so that
346 * it does not contain requests older than REND_HID_SERV_DIR_REQUERY_PERIOD
347 * seconds any more. */
349 directory_clean_last_hid_serv_requests(void)
352 time_t cutoff
= time(NULL
) - REND_HID_SERV_DIR_REQUERY_PERIOD
;
353 if (!last_hid_serv_requests
)
354 last_hid_serv_requests
= strmap_new();
355 for (iter
= strmap_iter_init(last_hid_serv_requests
);
356 !strmap_iter_done(iter
); ) {
360 strmap_iter_get(iter
, &key
, &val
);
361 ent
= (time_t *) val
;
363 iter
= strmap_iter_next_rmv(last_hid_serv_requests
, iter
);
366 iter
= strmap_iter_next(last_hid_serv_requests
, iter
);
371 /** Determine the responsible hidden service directories for <b>desc_id</b>
372 * and fetch the descriptor belonging to that ID from one of them. Only
373 * send a request to hidden service directories that we did not try within
374 * the last REND_HID_SERV_DIR_REQUERY_PERIOD seconds; on success, return 1,
375 * in the case that no hidden service directory is left to ask for the
376 * descriptor, return 0, and in case of a failure -1. <b>query</b> is only
377 * passed for pretty log statements. */
379 directory_get_from_hs_dir(const char *desc_id
, const rend_data_t
*rend_query
)
381 smartlist_t
*responsible_dirs
= smartlist_create();
382 routerstatus_t
*hs_dir
;
383 char desc_id_base32
[REND_DESC_ID_V2_LEN_BASE32
+ 1];
384 time_t now
= time(NULL
);
385 char descriptor_cookie_base64
[3*REND_DESC_COOKIE_LEN_BASE64
];
387 tor_assert(rend_query
);
388 /* Determine responsible dirs. Even if we can't get all we want,
389 * work with the ones we have. If it's empty, we'll notice below. */
390 (int) hid_serv_get_responsible_directories(responsible_dirs
, desc_id
);
392 base32_encode(desc_id_base32
, sizeof(desc_id_base32
),
393 desc_id
, DIGEST_LEN
);
395 /* Only select those hidden service directories to which we did not send
396 * a request recently and for which we have a router descriptor here. */
397 directory_clean_last_hid_serv_requests(); /* Clean request history first. */
399 SMARTLIST_FOREACH(responsible_dirs
, routerstatus_t
*, dir
, {
400 if (lookup_last_hid_serv_request(dir
, desc_id_base32
, 0, 0) +
401 REND_HID_SERV_DIR_REQUERY_PERIOD
>= now
||
402 !router_get_by_digest(dir
->identity_digest
))
403 SMARTLIST_DEL_CURRENT(responsible_dirs
, dir
);
406 hs_dir
= smartlist_choose(responsible_dirs
);
407 smartlist_free(responsible_dirs
);
409 log_info(LD_REND
, "Could not pick one of the responsible hidden "
410 "service directories, because we requested them all "
411 "recently without success.");
415 /* Remember, that we are requesting a descriptor from this hidden service
417 lookup_last_hid_serv_request(hs_dir
, desc_id_base32
, now
, 1);
419 /* Encode descriptor cookie for logging purposes. */
420 if (rend_query
->auth_type
!= REND_NO_AUTH
) {
421 if (base64_encode(descriptor_cookie_base64
,
422 sizeof(descriptor_cookie_base64
),
423 rend_query
->descriptor_cookie
, REND_DESC_COOKIE_LEN
)<0) {
424 log_warn(LD_BUG
, "Could not base64-encode descriptor cookie.");
427 /* Remove == signs and newline. */
428 descriptor_cookie_base64
[strlen(descriptor_cookie_base64
)-3] = '\0';
430 strlcpy(descriptor_cookie_base64
, "(none)",
431 sizeof(descriptor_cookie_base64
));
434 /* Send fetch request. (Pass query and possibly descriptor cookie so that
435 * they can be written to the directory connection and be referred to when
436 * the response arrives. */
437 directory_initiate_command_routerstatus_rend(hs_dir
,
438 DIR_PURPOSE_FETCH_RENDDESC_V2
,
439 ROUTER_PURPOSE_GENERAL
,
440 1, desc_id_base32
, NULL
, 0, 0,
442 log_info(LD_REND
, "Sending fetch request for v2 descriptor for "
443 "service '%s' with descriptor ID '%s', auth type %d, "
444 "and descriptor cookie '%s' to hidden service "
445 "directory '%s' on port %d.",
446 rend_query
->onion_address
, desc_id_base32
,
447 rend_query
->auth_type
,
448 (rend_query
->auth_type
== REND_NO_AUTH
? "[none]" :
449 escaped_safe_str(descriptor_cookie_base64
)),
450 hs_dir
->nickname
, hs_dir
->dir_port
);
454 /** If we are not currently fetching a rendezvous service descriptor
455 * for the service ID <b>query</b>, start a directory connection to fetch a
459 rend_client_refetch_renddesc(const char *query
)
461 if (!get_options()->FetchHidServDescriptors
)
463 log_info(LD_REND
, "Fetching rendezvous descriptor for service %s",
464 escaped_safe_str(query
));
465 if (connection_get_by_type_state_rendquery(CONN_TYPE_DIR
, 0, query
, 0)) {
466 log_info(LD_REND
,"Would fetch a new renddesc here (for %s), but one is "
467 "already in progress.", escaped_safe_str(query
));
469 /* not one already; initiate a dir rend desc lookup */
470 directory_get_from_dirserver(DIR_PURPOSE_FETCH_RENDDESC
,
471 ROUTER_PURPOSE_GENERAL
, query
,
472 PDS_RETRY_IF_NO_SERVERS
);
476 /** Start a connection to a hidden service directory to fetch a v2
477 * rendezvous service descriptor for the base32-encoded service ID
481 rend_client_refetch_v2_renddesc(const rend_data_t
*rend_query
)
483 char descriptor_id
[DIGEST_LEN
];
484 int replicas_left_to_try
[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS
];
486 rend_cache_entry_t
*e
= NULL
;
487 tor_assert(rend_query
);
488 /* Are we configured to fetch descriptors? */
489 if (!get_options()->FetchHidServDescriptors
) {
490 log_warn(LD_REND
, "We received an onion address for a v2 rendezvous "
491 "service descriptor, but are not fetching service descriptors.");
494 /* Before fetching, check if we already have the descriptor here. */
495 if (rend_cache_lookup_entry(rend_query
->onion_address
, -1, &e
) > 0) {
496 log_info(LD_REND
, "We would fetch a v2 rendezvous descriptor, but we "
497 "already have that descriptor here. Not fetching.");
500 log_debug(LD_REND
, "Fetching v2 rendezvous descriptor for service %s",
501 safe_str(rend_query
->onion_address
));
502 /* Randomly iterate over the replicas until a descriptor can be fetched
503 * from one of the consecutive nodes, or no options are left. */
504 tries_left
= REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS
;
505 for (i
= 0; i
< REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS
; i
++)
506 replicas_left_to_try
[i
] = i
;
507 while (tries_left
> 0) {
508 int rand
= crypto_rand_int(tries_left
);
509 int chosen_replica
= replicas_left_to_try
[rand
];
510 replicas_left_to_try
[rand
] = replicas_left_to_try
[--tries_left
];
512 if (rend_compute_v2_desc_id(descriptor_id
, rend_query
->onion_address
,
513 rend_query
->auth_type
== REND_STEALTH_AUTH
?
514 rend_query
->descriptor_cookie
: NULL
,
515 time(NULL
), chosen_replica
) < 0) {
516 log_warn(LD_REND
, "Internal error: Computing v2 rendezvous "
517 "descriptor ID did not succeed.");
520 if (directory_get_from_hs_dir(descriptor_id
, rend_query
) != 0)
521 return; /* either success or failure, but we're done */
523 /* If we come here, there are no hidden service directories left. */
524 log_info(LD_REND
, "Could not pick one of the responsible hidden "
525 "service directories to fetch descriptors, because "
526 "we already tried them all unsuccessfully.");
527 /* Close pending connections (unless a v0 request is still going on). */
528 rend_client_desc_trynow(rend_query
->onion_address
, 2);
532 /** Remove failed_intro from ent. If ent now has no intro points, or
533 * service is unrecognized, then launch a new renddesc fetch.
535 * Return -1 if error, 0 if no intro points remain or service
536 * unrecognized, 1 if recognized and some intro points remain.
539 rend_client_remove_intro_point(extend_info_t
*failed_intro
,
540 const rend_data_t
*rend_query
)
543 rend_cache_entry_t
*ent
;
546 r
= rend_cache_lookup_entry(rend_query
->onion_address
, -1, &ent
);
548 log_warn(LD_BUG
, "Malformed service ID %s.",
549 escaped_safe_str(rend_query
->onion_address
));
553 log_info(LD_REND
, "Unknown service %s. Re-fetching descriptor.",
554 escaped_safe_str(rend_query
->onion_address
));
555 /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever
556 * arrives first. Exception: When using client authorization, only
557 * fetch v2 descriptors.*/
558 rend_client_refetch_v2_renddesc(rend_query
);
559 if (rend_query
->auth_type
== REND_NO_AUTH
)
560 rend_client_refetch_renddesc(rend_query
->onion_address
);
564 for (i
= 0; i
< smartlist_len(ent
->parsed
->intro_nodes
); i
++) {
565 rend_intro_point_t
*intro
= smartlist_get(ent
->parsed
->intro_nodes
, i
);
566 if (!memcmp(failed_intro
->identity_digest
,
567 intro
->extend_info
->identity_digest
, DIGEST_LEN
)) {
568 rend_intro_point_free(intro
);
569 smartlist_del(ent
->parsed
->intro_nodes
, i
);
574 if (smartlist_len(ent
->parsed
->intro_nodes
) == 0) {
576 "No more intro points remain for %s. Re-fetching descriptor.",
577 escaped_safe_str(rend_query
->onion_address
));
578 /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever
579 * arrives first. Exception: When using client authorization, only
580 * fetch v2 descriptors.*/
581 rend_client_refetch_v2_renddesc(rend_query
);
582 if (rend_query
->auth_type
== REND_NO_AUTH
)
583 rend_client_refetch_renddesc(rend_query
->onion_address
);
585 /* move all pending streams back to renddesc_wait */
586 while ((conn
= connection_get_by_type_state_rendquery(CONN_TYPE_AP
,
587 AP_CONN_STATE_CIRCUIT_WAIT
,
588 rend_query
->onion_address
, -1))) {
589 conn
->state
= AP_CONN_STATE_RENDDESC_WAIT
;
594 log_info(LD_REND
,"%d options left for %s.",
595 smartlist_len(ent
->parsed
->intro_nodes
),
596 escaped_safe_str(rend_query
->onion_address
));
600 /** Called when we receive a RENDEZVOUS_ESTABLISHED cell; changes the state of
601 * the circuit to C_REND_READY.
604 rend_client_rendezvous_acked(origin_circuit_t
*circ
, const char *request
,
609 /* we just got an ack for our establish-rendezvous. switch purposes. */
610 if (circ
->_base
.purpose
!= CIRCUIT_PURPOSE_C_ESTABLISH_REND
) {
611 log_warn(LD_PROTOCOL
,"Got a rendezvous ack when we weren't expecting one. "
613 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_TORPROTOCOL
);
616 log_info(LD_REND
,"Got rendezvous ack. This circuit is now ready for "
618 circ
->_base
.purpose
= CIRCUIT_PURPOSE_C_REND_READY
;
619 /* XXXX022 This is a pretty brute-force approach. It'd be better to
620 * attach only the connections that are waiting on this circuit, rather
621 * than trying to attach them all. See comments bug 743. */
622 /* If we already have the introduction circuit built, make sure we send
623 * the INTRODUCE cell _now_ */
624 connection_ap_attach_pending();
628 /** Bob sent us a rendezvous cell; join the circuits. */
630 rend_client_receive_rendezvous(origin_circuit_t
*circ
, const char *request
,
634 char keys
[DIGEST_LEN
+CPATH_KEY_MATERIAL_LEN
];
636 if ((circ
->_base
.purpose
!= CIRCUIT_PURPOSE_C_REND_READY
&&
637 circ
->_base
.purpose
!= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED
)
638 || !circ
->build_state
->pending_final_cpath
) {
639 log_warn(LD_PROTOCOL
,"Got rendezvous2 cell from hidden service, but not "
640 "expecting it. Closing.");
641 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_TORPROTOCOL
);
645 if (request_len
!= DH_KEY_LEN
+DIGEST_LEN
) {
646 log_warn(LD_PROTOCOL
,"Incorrect length (%d) on RENDEZVOUS2 cell.",
651 log_info(LD_REND
,"Got RENDEZVOUS2 cell from hidden service.");
653 /* first DH_KEY_LEN bytes are g^y from bob. Finish the dh handshake...*/
654 tor_assert(circ
->build_state
);
655 tor_assert(circ
->build_state
->pending_final_cpath
);
656 hop
= circ
->build_state
->pending_final_cpath
;
657 tor_assert(hop
->dh_handshake_state
);
658 if (crypto_dh_compute_secret(hop
->dh_handshake_state
, request
, DH_KEY_LEN
,
659 keys
, DIGEST_LEN
+CPATH_KEY_MATERIAL_LEN
)<0) {
660 log_warn(LD_GENERAL
, "Couldn't complete DH handshake.");
663 /* ... and set up cpath. */
664 if (circuit_init_cpath_crypto(hop
, keys
+DIGEST_LEN
, 0)<0)
667 /* Check whether the digest is right... */
668 if (memcmp(keys
, request
+DH_KEY_LEN
, DIGEST_LEN
)) {
669 log_warn(LD_PROTOCOL
, "Incorrect digest of key material.");
673 crypto_dh_free(hop
->dh_handshake_state
);
674 hop
->dh_handshake_state
= NULL
;
676 /* All is well. Extend the circuit. */
677 circ
->_base
.purpose
= CIRCUIT_PURPOSE_C_REND_JOINED
;
678 hop
->state
= CPATH_STATE_OPEN
;
679 /* set the windows to default. these are the windows
680 * that alice thinks bob has.
682 hop
->package_window
= CIRCWINDOW_START
;
683 hop
->deliver_window
= CIRCWINDOW_START
;
685 onion_append_to_cpath(&circ
->cpath
, hop
);
686 circ
->build_state
->pending_final_cpath
= NULL
; /* prevent double-free */
687 /* XXXX022 This is a pretty brute-force approach. It'd be better to
688 * attach only the connections that are waiting on this circuit, rather
689 * than trying to attach them all. See comments bug 743. */
690 connection_ap_attach_pending();
693 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_TORPROTOCOL
);
697 /** Find all the apconns in state AP_CONN_STATE_RENDDESC_WAIT that
698 * are waiting on query. If there's a working cache entry here
699 * with at least one intro point, move them to the next state. If
700 * <b>rend_version</b> is non-negative, fail connections that have
701 * requested <b>query</b> unless there are still descriptor fetch
702 * requests in progress for other descriptor versions than
703 * <b>rend_version</b>.
706 rend_client_desc_trynow(const char *query
, int rend_version
)
708 edge_connection_t
*conn
;
709 rend_cache_entry_t
*entry
;
710 time_t now
= time(NULL
);
712 smartlist_t
*conns
= get_connection_array();
713 SMARTLIST_FOREACH(conns
, connection_t
*, _conn
,
715 if (_conn
->type
!= CONN_TYPE_AP
||
716 _conn
->state
!= AP_CONN_STATE_RENDDESC_WAIT
||
717 _conn
->marked_for_close
)
719 conn
= TO_EDGE_CONN(_conn
);
720 if (!conn
->rend_data
)
722 if (rend_cmp_service_ids(query
, conn
->rend_data
->onion_address
))
724 assert_connection_ok(TO_CONN(conn
), now
);
725 if (rend_cache_lookup_entry(conn
->rend_data
->onion_address
, -1,
727 smartlist_len(entry
->parsed
->intro_nodes
) > 0) {
728 /* either this fetch worked, or it failed but there was a
729 * valid entry from before which we should reuse */
730 log_info(LD_REND
,"Rend desc is usable. Launching circuits.");
731 conn
->_base
.state
= AP_CONN_STATE_CIRCUIT_WAIT
;
733 /* restart their timeout values, so they get a fair shake at
734 * connecting to the hidden service. */
735 conn
->_base
.timestamp_created
= now
;
736 conn
->_base
.timestamp_lastread
= now
;
737 conn
->_base
.timestamp_lastwritten
= now
;
739 if (connection_ap_handshake_attach_circuit(conn
) < 0) {
740 /* it will never work */
741 log_warn(LD_REND
,"Rendezvous attempt failed. Closing.");
742 if (!conn
->_base
.marked_for_close
)
743 connection_mark_unattached_ap(conn
, END_STREAM_REASON_CANT_ATTACH
);
745 } else { /* 404, or fetch didn't get that far */
746 /* Unless there are requests for another descriptor version pending,
747 * close the connection. */
748 if (rend_version
>= 0 &&
749 !connection_get_by_type_state_rendquery(CONN_TYPE_DIR
, 0, query
,
750 rend_version
== 0 ? 2 : 0)) {
751 log_notice(LD_REND
,"Closing stream for '%s.onion': hidden service is "
752 "unavailable (try again later).", safe_str(query
));
753 connection_mark_unattached_ap(conn
, END_STREAM_REASON_RESOLVEFAILED
);
759 /** Return a newly allocated extend_info_t* for a randomly chosen introduction
760 * point for the named hidden service. Return NULL if all introduction points
761 * have been tried and failed.
764 rend_client_get_random_intro(const rend_data_t
*rend_query
)
767 rend_cache_entry_t
*entry
;
768 rend_intro_point_t
*intro
;
769 routerinfo_t
*router
;
771 if (rend_cache_lookup_entry(rend_query
->onion_address
, -1, &entry
) < 1) {
773 "Query '%s' didn't have valid rend desc in cache. Failing.",
774 safe_str(rend_query
->onion_address
));
779 if (smartlist_len(entry
->parsed
->intro_nodes
) == 0)
782 i
= crypto_rand_int(smartlist_len(entry
->parsed
->intro_nodes
));
783 intro
= smartlist_get(entry
->parsed
->intro_nodes
, i
);
784 /* Do we need to look up the router or is the extend info complete? */
785 if (!intro
->extend_info
->onion_key
) {
786 router
= router_get_by_nickname(intro
->extend_info
->nickname
, 0);
788 log_info(LD_REND
, "Unknown router with nickname '%s'; trying another.",
789 intro
->extend_info
->nickname
);
790 rend_intro_point_free(intro
);
791 smartlist_del(entry
->parsed
->intro_nodes
, i
);
794 extend_info_free(intro
->extend_info
);
795 intro
->extend_info
= extend_info_from_router(router
);
797 return extend_info_dup(intro
->extend_info
);
800 /** Client-side authorizations for hidden services; map of onion address to
801 * rend_service_authorization_t*. */
802 static strmap_t
*auth_hid_servs
= NULL
;
804 /** Look up the client-side authorization for the hidden service with
805 * <b>onion_address</b>. Return NULL if no authorization is available for
807 rend_service_authorization_t
*
808 rend_client_lookup_service_authorization(const char *onion_address
)
810 tor_assert(onion_address
);
811 if (!auth_hid_servs
) return NULL
;
812 return strmap_get(auth_hid_servs
, onion_address
);
815 /** Helper: Free storage held by rend_service_authorization_t. */
817 rend_service_authorization_free(rend_service_authorization_t
*auth
)
822 /** Helper for strmap_free. */
824 rend_service_authorization_strmap_item_free(void *service_auth
)
826 rend_service_authorization_free(service_auth
);
829 /** Release all the storage held in auth_hid_servs.
832 rend_service_authorization_free_all(void)
834 if (!auth_hid_servs
) {
837 strmap_free(auth_hid_servs
, rend_service_authorization_strmap_item_free
);
838 auth_hid_servs
= NULL
;
841 /** Parse <b>config_line</b> as a client-side authorization for a hidden
842 * service and add it to the local map of hidden service authorizations.
843 * Return 0 for success and -1 for failure. */
845 rend_parse_service_authorization(or_options_t
*options
, int validate_only
)
849 strmap_t
*parsed
= strmap_new();
850 smartlist_t
*sl
= smartlist_create();
851 rend_service_authorization_t
*auth
= NULL
;
853 for (line
= options
->HidServAuth
; line
; line
= line
->next
) {
854 char *onion_address
, *descriptor_cookie
;
855 char descriptor_cookie_tmp
[REND_DESC_COOKIE_LEN
+2];
856 char descriptor_cookie_base64ext
[REND_DESC_COOKIE_LEN_BASE64
+2+1];
857 int auth_type_val
= 0;
859 SMARTLIST_FOREACH(sl
, char *, c
, tor_free(c
););
861 smartlist_split_string(sl
, line
->value
, " ",
862 SPLIT_SKIP_SPACE
|SPLIT_IGNORE_BLANK
, 3);
863 if (smartlist_len(sl
) < 2) {
864 log_warn(LD_CONFIG
, "Configuration line does not consist of "
865 "\"onion-address authorization-cookie [service-name]\": "
866 "'%s'", line
->value
);
869 auth
= tor_malloc_zero(sizeof(rend_service_authorization_t
));
870 /* Parse onion address. */
871 onion_address
= smartlist_get(sl
, 0);
872 if (strlen(onion_address
) != REND_SERVICE_ADDRESS_LEN
||
873 strcmpend(onion_address
, ".onion")) {
874 log_warn(LD_CONFIG
, "Onion address has wrong format: '%s'",
878 strlcpy(auth
->onion_address
, onion_address
, REND_SERVICE_ID_LEN_BASE32
+1);
879 if (!rend_valid_service_id(auth
->onion_address
)) {
880 log_warn(LD_CONFIG
, "Onion address has wrong format: '%s'",
884 /* Parse descriptor cookie. */
885 descriptor_cookie
= smartlist_get(sl
, 1);
886 if (strlen(descriptor_cookie
) != REND_DESC_COOKIE_LEN_BASE64
) {
887 log_warn(LD_CONFIG
, "Authorization cookie has wrong length: '%s'",
891 /* Add trailing zero bytes (AA) to make base64-decoding happy. */
892 tor_snprintf(descriptor_cookie_base64ext
,
893 REND_DESC_COOKIE_LEN_BASE64
+2+1,
894 "%sAA", descriptor_cookie
);
895 if (base64_decode(descriptor_cookie_tmp
, sizeof(descriptor_cookie_tmp
),
896 descriptor_cookie_base64ext
,
897 strlen(descriptor_cookie_base64ext
)) < 0) {
898 log_warn(LD_CONFIG
, "Decoding authorization cookie failed: '%s'",
902 auth_type_val
= (descriptor_cookie_tmp
[16] >> 4) + 1;
903 if (auth_type_val
< 1 || auth_type_val
> 2) {
904 log_warn(LD_CONFIG
, "Authorization cookie has unknown authorization "
908 auth
->auth_type
= auth_type_val
== 1 ? REND_BASIC_AUTH
: REND_STEALTH_AUTH
;
909 memcpy(auth
->descriptor_cookie
, descriptor_cookie_tmp
,
910 REND_DESC_COOKIE_LEN
);
911 if (strmap_get(parsed
, auth
->onion_address
)) {
912 log_warn(LD_CONFIG
, "Duplicate authorization for the same hidden "
916 strmap_set(parsed
, auth
->onion_address
, auth
);
925 rend_service_authorization_free(auth
);
926 SMARTLIST_FOREACH(sl
, char *, c
, tor_free(c
););
928 if (!validate_only
&& res
== 0) {
929 rend_service_authorization_free_all();
930 auth_hid_servs
= parsed
;
932 strmap_free(parsed
, rend_service_authorization_strmap_item_free
);