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
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
|
/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file rendclient.c
* \brief Client code to access location-hidden services.
**/
#include "or.h"
#include "circpathbias.h"
#include "circuitbuild.h"
#include "circuitlist.h"
#include "circuituse.h"
#include "config.h"
#include "connection.h"
#include "connection_edge.h"
#include "directory.h"
#include "main.h"
#include "networkstatus.h"
#include "nodelist.h"
#include "relay.h"
#include "rendclient.h"
#include "rendcommon.h"
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
#include "routerset.h"
#include "control.h"
static extend_info_t *rend_client_get_random_intro_impl(
const rend_cache_entry_t *rend_query,
const int strict, const int warnings);
/** Purge all potentially remotely-detectable state held in the hidden
* service client code. Called on SIGNAL NEWNYM. */
void
rend_client_purge_state(void)
{
rend_cache_purge();
rend_client_cancel_descriptor_fetches();
rend_client_purge_last_hid_serv_requests();
}
/** Called when we've established a circuit to an introduction point:
* send the introduction request. */
void
rend_client_introcirc_has_opened(origin_circuit_t *circ)
{
tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
tor_assert(circ->cpath);
log_info(LD_REND,"introcirc is open");
connection_ap_attach_pending();
}
/** Send the establish-rendezvous cell along a rendezvous circuit. if
* it fails, mark the circ for close and return -1. else return 0.
*/
static int
rend_client_send_establish_rendezvous(origin_circuit_t *circ)
{
tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
tor_assert(circ->rend_data);
log_info(LD_REND, "Sending an ESTABLISH_RENDEZVOUS cell");
if (crypto_rand(circ->rend_data->rend_cookie, REND_COOKIE_LEN) < 0) {
log_warn(LD_BUG, "Internal error: Couldn't produce random cookie.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return -1;
}
/* Set timestamp_dirty, because circuit_expire_building expects it,
* and the rend cookie also means we've used the circ. */
circ->base_.timestamp_dirty = time(NULL);
/* We've attempted to use this circuit. Probe it if we fail */
pathbias_count_use_attempt(circ);
if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
RELAY_COMMAND_ESTABLISH_RENDEZVOUS,
circ->rend_data->rend_cookie,
REND_COOKIE_LEN,
circ->cpath->prev)<0) {
/* circ is already marked for close */
log_warn(LD_GENERAL, "Couldn't send ESTABLISH_RENDEZVOUS cell");
return -1;
}
return 0;
}
/** Extend the introduction circuit <b>circ</b> to another valid
* introduction point for the hidden service it is trying to connect
* to, or mark it and launch a new circuit if we can't extend it.
* Return 0 on success or possible success. Return -1 and mark the
* introduction circuit for close on permanent failure.
*
* On failure, the caller is responsible for marking the associated
* rendezvous circuit for close. */
static int
rend_client_reextend_intro_circuit(origin_circuit_t *circ)
{
extend_info_t *extend_info;
int result;
extend_info = rend_client_get_random_intro(circ->rend_data);
if (!extend_info) {
log_warn(LD_REND,
"No usable introduction points left for %s. Closing.",
safe_str_client(circ->rend_data->onion_address));
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return -1;
}
// XXX: should we not re-extend if hs_circ_has_timed_out?
if (circ->remaining_relay_early_cells) {
log_info(LD_REND,
"Re-extending circ %u, this time to %s.",
(unsigned)circ->base_.n_circ_id,
safe_str_client(extend_info_describe(extend_info)));
result = circuit_extend_to_new_exit(circ, extend_info);
} else {
log_info(LD_REND,
"Closing intro circ %u (out of RELAY_EARLY cells).",
(unsigned)circ->base_.n_circ_id);
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
/* connection_ap_handshake_attach_circuit will launch a new intro circ. */
result = 0;
}
extend_info_free(extend_info);
return result;
}
/** Return true iff we should send timestamps in our INTRODUCE1 cells */
static int
rend_client_should_send_timestamp(void)
{
if (get_options()->Support022HiddenServices >= 0)
return get_options()->Support022HiddenServices;
return networkstatus_get_param(NULL, "Support022HiddenServices", 1, 0, 1);
}
/** Called when we're trying to connect an ap conn; sends an INTRODUCE1 cell
* down introcirc if possible.
*/
int
rend_client_send_introduction(origin_circuit_t *introcirc,
origin_circuit_t *rendcirc)
{
size_t payload_len;
int r, v3_shift = 0;
char payload[RELAY_PAYLOAD_SIZE];
char tmp[RELAY_PAYLOAD_SIZE];
rend_cache_entry_t *entry;
crypt_path_t *cpath;
off_t dh_offset;
crypto_pk_t *intro_key = NULL;
int status = 0;
tor_assert(introcirc->base_.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
tor_assert(rendcirc->base_.purpose == CIRCUIT_PURPOSE_C_REND_READY);
tor_assert(introcirc->rend_data);
tor_assert(rendcirc->rend_data);
tor_assert(!rend_cmp_service_ids(introcirc->rend_data->onion_address,
rendcirc->rend_data->onion_address));
#ifndef NON_ANONYMOUS_MODE_ENABLED
tor_assert(!(introcirc->build_state->onehop_tunnel));
tor_assert(!(rendcirc->build_state->onehop_tunnel));
#endif
if (rend_cache_lookup_entry(introcirc->rend_data->onion_address, -1,
&entry) < 1) {
log_info(LD_REND,
"query %s didn't have valid rend desc in cache. "
"Refetching descriptor.",
safe_str_client(introcirc->rend_data->onion_address));
rend_client_refetch_v2_renddesc(introcirc->rend_data);
{
connection_t *conn;
while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP,
AP_CONN_STATE_CIRCUIT_WAIT,
introcirc->rend_data->onion_address))) {
conn->state = AP_CONN_STATE_RENDDESC_WAIT;
}
}
status = -1;
goto cleanup;
}
/* first 20 bytes of payload are the hash of Bob's pk */
intro_key = NULL;
SMARTLIST_FOREACH(entry->parsed->intro_nodes, rend_intro_point_t *,
intro, {
if (tor_memeq(introcirc->build_state->chosen_exit->identity_digest,
intro->extend_info->identity_digest, DIGEST_LEN)) {
intro_key = intro->intro_key;
break;
}
});
if (!intro_key) {
log_info(LD_REND, "Could not find intro key for %s at %s; we "
"have a v2 rend desc with %d intro points. "
"Trying a different intro point...",
safe_str_client(introcirc->rend_data->onion_address),
safe_str_client(extend_info_describe(
introcirc->build_state->chosen_exit)),
smartlist_len(entry->parsed->intro_nodes));
if (rend_client_reextend_intro_circuit(introcirc)) {
status = -2;
goto perm_err;
} else {
status = -1;
goto cleanup;
}
}
if (crypto_pk_get_digest(intro_key, payload)<0) {
log_warn(LD_BUG, "Internal error: couldn't hash public key.");
status = -2;
goto perm_err;
}
/* Initialize the pending_final_cpath and start the DH handshake. */
cpath = rendcirc->build_state->pending_final_cpath;
if (!cpath) {
cpath = rendcirc->build_state->pending_final_cpath =
tor_malloc_zero(sizeof(crypt_path_t));
cpath->magic = CRYPT_PATH_MAGIC;
if (!(cpath->rend_dh_handshake_state = crypto_dh_new(DH_TYPE_REND))) {
log_warn(LD_BUG, "Internal error: couldn't allocate DH.");
status = -2;
goto perm_err;
}
if (crypto_dh_generate_public(cpath->rend_dh_handshake_state)<0) {
log_warn(LD_BUG, "Internal error: couldn't generate g^x.");
status = -2;
goto perm_err;
}
}
/* If version is 3, write (optional) auth data and timestamp. */
if (entry->parsed->protocols & (1<<3)) {
tmp[0] = 3; /* version 3 of the cell format */
tmp[1] = (uint8_t)introcirc->rend_data->auth_type; /* auth type, if any */
v3_shift = 1;
if (introcirc->rend_data->auth_type != REND_NO_AUTH) {
set_uint16(tmp+2, htons(REND_DESC_COOKIE_LEN));
memcpy(tmp+4, introcirc->rend_data->descriptor_cookie,
REND_DESC_COOKIE_LEN);
v3_shift += 2+REND_DESC_COOKIE_LEN;
}
if (rend_client_should_send_timestamp()) {
uint32_t now = (uint32_t)time(NULL);
now += 300;
now -= now % 600;
set_uint32(tmp+v3_shift+1, htonl(now));
} else {
set_uint32(tmp+v3_shift+1, 0);
}
v3_shift += 4;
} /* if version 2 only write version number */
else if (entry->parsed->protocols & (1<<2)) {
tmp[0] = 2; /* version 2 of the cell format */
}
/* write the remaining items into tmp */
if (entry->parsed->protocols & (1<<3) || entry->parsed->protocols & (1<<2)) {
/* version 2 format */
extend_info_t *extend_info = rendcirc->build_state->chosen_exit;
int klen;
/* nul pads */
set_uint32(tmp+v3_shift+1, tor_addr_to_ipv4h(&extend_info->addr));
set_uint16(tmp+v3_shift+5, htons(extend_info->port));
memcpy(tmp+v3_shift+7, extend_info->identity_digest, DIGEST_LEN);
klen = crypto_pk_asn1_encode(extend_info->onion_key,
tmp+v3_shift+7+DIGEST_LEN+2,
sizeof(tmp)-(v3_shift+7+DIGEST_LEN+2));
set_uint16(tmp+v3_shift+7+DIGEST_LEN, htons(klen));
memcpy(tmp+v3_shift+7+DIGEST_LEN+2+klen, rendcirc->rend_data->rend_cookie,
REND_COOKIE_LEN);
dh_offset = v3_shift+7+DIGEST_LEN+2+klen+REND_COOKIE_LEN;
} else {
/* Version 0. */
strncpy(tmp, rendcirc->build_state->chosen_exit->nickname,
(MAX_NICKNAME_LEN+1)); /* nul pads */
memcpy(tmp+MAX_NICKNAME_LEN+1, rendcirc->rend_data->rend_cookie,
REND_COOKIE_LEN);
dh_offset = MAX_NICKNAME_LEN+1+REND_COOKIE_LEN;
}
if (crypto_dh_get_public(cpath->rend_dh_handshake_state, tmp+dh_offset,
DH_KEY_LEN)<0) {
log_warn(LD_BUG, "Internal error: couldn't extract g^x.");
status = -2;
goto perm_err;
}
note_crypto_pk_op(REND_CLIENT);
/*XXX maybe give crypto_pk_public_hybrid_encrypt a max_len arg,
* to avoid buffer overflows? */
r = crypto_pk_public_hybrid_encrypt(intro_key, payload+DIGEST_LEN,
sizeof(payload)-DIGEST_LEN,
tmp,
(int)(dh_offset+DH_KEY_LEN),
PK_PKCS1_OAEP_PADDING, 0);
if (r<0) {
log_warn(LD_BUG,"Internal error: hybrid pk encrypt failed.");
status = -2;
goto perm_err;
}
payload_len = DIGEST_LEN + r;
tor_assert(payload_len <= RELAY_PAYLOAD_SIZE); /* we overran something */
/* Copy the rendezvous cookie from rendcirc to introcirc, so that
* when introcirc gets an ack, we can change the state of the right
* rendezvous circuit. */
memcpy(introcirc->rend_data->rend_cookie, rendcirc->rend_data->rend_cookie,
REND_COOKIE_LEN);
log_info(LD_REND, "Sending an INTRODUCE1 cell");
if (relay_send_command_from_edge(0, TO_CIRCUIT(introcirc),
RELAY_COMMAND_INTRODUCE1,
payload, payload_len,
introcirc->cpath->prev)<0) {
/* introcirc is already marked for close. leave rendcirc alone. */
log_warn(LD_BUG, "Couldn't send INTRODUCE1 cell");
status = -2;
goto cleanup;
}
/* Now, we wait for an ACK or NAK on this circuit. */
circuit_change_purpose(TO_CIRCUIT(introcirc),
CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT);
/* Set timestamp_dirty, because circuit_expire_building expects it
* to specify when a circuit entered the _C_INTRODUCE_ACK_WAIT
* state. */
introcirc->base_.timestamp_dirty = time(NULL);
pathbias_count_use_attempt(introcirc);
goto cleanup;
perm_err:
if (!introcirc->base_.marked_for_close)
circuit_mark_for_close(TO_CIRCUIT(introcirc), END_CIRC_REASON_INTERNAL);
circuit_mark_for_close(TO_CIRCUIT(rendcirc), END_CIRC_REASON_INTERNAL);
cleanup:
memwipe(payload, 0, sizeof(payload));
memwipe(tmp, 0, sizeof(tmp));
return status;
}
/** Called when a rendezvous circuit is open; sends a establish
* rendezvous circuit as appropriate. */
void
rend_client_rendcirc_has_opened(origin_circuit_t *circ)
{
tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
log_info(LD_REND,"rendcirc is open");
/* generate a rendezvous cookie, store it in circ */
if (rend_client_send_establish_rendezvous(circ) < 0) {
return;
}
}
/**
* Called to close other intro circuits we launched in parallel
* due to timeout.
*/
static void
rend_client_close_other_intros(const char *onion_address)
{
circuit_t *c;
/* abort parallel intro circs, if any */
TOR_LIST_FOREACH(c, circuit_get_global_list(), head) {
if ((c->purpose == CIRCUIT_PURPOSE_C_INTRODUCING ||
c->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) &&
!c->marked_for_close && CIRCUIT_IS_ORIGIN(c)) {
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(c);
if (oc->rend_data &&
!rend_cmp_service_ids(onion_address,
oc->rend_data->onion_address)) {
log_info(LD_REND|LD_CIRC, "Closing introduction circuit %d that we "
"built in parallel (Purpose %d).", oc->global_identifier,
c->purpose);
circuit_mark_for_close(c, END_CIRC_REASON_TIMEOUT);
}
}
}
}
/** Called when get an ACK or a NAK for a REND_INTRODUCE1 cell.
*/
int
rend_client_introduction_acked(origin_circuit_t *circ,
const uint8_t *request, size_t request_len)
{
origin_circuit_t *rendcirc;
(void) request; // XXXX Use this.
if (circ->base_.purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
log_warn(LD_PROTOCOL,
"Received REND_INTRODUCE_ACK on unexpected circuit %u.",
(unsigned)circ->base_.n_circ_id);
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
tor_assert(circ->build_state->chosen_exit);
#ifndef NON_ANONYMOUS_MODE_ENABLED
tor_assert(!(circ->build_state->onehop_tunnel));
#endif
tor_assert(circ->rend_data);
/* For path bias: This circuit was used successfully. Valid
* nacks and acks count. */
pathbias_mark_use_success(circ);
if (request_len == 0) {
/* It's an ACK; the introduction point relayed our introduction request. */
/* Locate the rend circ which is waiting to hear about this ack,
* and tell it.
*/
log_info(LD_REND,"Received ack. Telling rend circ...");
rendcirc = circuit_get_ready_rend_circ_by_rend_data(circ->rend_data);
if (rendcirc) { /* remember the ack */
#ifndef NON_ANONYMOUS_MODE_ENABLED
tor_assert(!(rendcirc->build_state->onehop_tunnel));
#endif
circuit_change_purpose(TO_CIRCUIT(rendcirc),
CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED);
/* Set timestamp_dirty, because circuit_expire_building expects
* it to specify when a circuit entered the
* _C_REND_READY_INTRO_ACKED state. */
rendcirc->base_.timestamp_dirty = time(NULL);
} else {
log_info(LD_REND,"...Found no rend circ. Dropping on the floor.");
}
/* close the circuit: we won't need it anymore. */
circuit_change_purpose(TO_CIRCUIT(circ),
CIRCUIT_PURPOSE_C_INTRODUCE_ACKED);
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
/* close any other intros launched in parallel */
rend_client_close_other_intros(circ->rend_data->onion_address);
} else {
/* It's a NAK; the introduction point didn't relay our request. */
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_INTRODUCING);
/* Remove this intro point from the set of viable introduction
* points. If any remain, extend to a new one and try again.
* If none remain, refetch the service descriptor.
*/
log_info(LD_REND, "Got nack for %s from %s...",
safe_str_client(circ->rend_data->onion_address),
safe_str_client(extend_info_describe(circ->build_state->chosen_exit)));
if (rend_client_report_intro_point_failure(circ->build_state->chosen_exit,
circ->rend_data,
INTRO_POINT_FAILURE_GENERIC)>0) {
/* There are introduction points left. Re-extend the circuit to
* another intro point and try again. */
int result = rend_client_reextend_intro_circuit(circ);
/* XXXX If that call failed, should we close the rend circuit,
* too? */
return result;
}
}
return 0;
}
/** The period for which a hidden service directory cannot be queried for
* the same descriptor ID again. */
#define REND_HID_SERV_DIR_REQUERY_PERIOD (15 * 60)
/** Contains the last request times to hidden service directories for
* certain queries; each key is a string consisting of the
* concatenation of a base32-encoded HS directory identity digest, a
* base32-encoded HS descriptor ID, and a hidden service address
* (without the ".onion" part); each value is a pointer to a time_t
* holding the time of the last request for that descriptor ID to that
* HS directory. */
static strmap_t *last_hid_serv_requests_ = NULL;
/** Returns last_hid_serv_requests_, initializing it to a new strmap if
* necessary. */
static strmap_t *
get_last_hid_serv_requests(void)
{
if (!last_hid_serv_requests_)
last_hid_serv_requests_ = strmap_new();
return last_hid_serv_requests_;
}
#define LAST_HID_SERV_REQUEST_KEY_LEN (REND_DESC_ID_V2_LEN_BASE32 + \
REND_DESC_ID_V2_LEN_BASE32 + \
REND_SERVICE_ID_LEN_BASE32)
/** Look up the last request time to hidden service directory <b>hs_dir</b>
* for descriptor ID <b>desc_id_base32</b> for the service specified in
* <b>rend_query</b>. If <b>set</b> is non-zero,
* assign the current time <b>now</b> and return that. Otherwise, return
* the most recent request time, or 0 if no such request has been sent
* before. */
static time_t
lookup_last_hid_serv_request(routerstatus_t *hs_dir,
const char *desc_id_base32,
const rend_data_t *rend_query,
time_t now, int set)
{
char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
char hsdir_desc_comb_id[LAST_HID_SERV_REQUEST_KEY_LEN + 1];
time_t *last_request_ptr;
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32),
hs_dir->identity_digest, DIGEST_LEN);
tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s%s",
hsdir_id_base32,
desc_id_base32,
rend_query->onion_address);
/* XXX023 tor_assert(strlen(hsdir_desc_comb_id) ==
LAST_HID_SERV_REQUEST_KEY_LEN); */
if (set) {
time_t *oldptr;
last_request_ptr = tor_malloc_zero(sizeof(time_t));
*last_request_ptr = now;
oldptr = strmap_set(last_hid_serv_requests, hsdir_desc_comb_id,
last_request_ptr);
tor_free(oldptr);
} else
last_request_ptr = strmap_get_lc(last_hid_serv_requests,
hsdir_desc_comb_id);
return (last_request_ptr) ? *last_request_ptr : 0;
}
/** Clean the history of request times to hidden service directories, so that
* it does not contain requests older than REND_HID_SERV_DIR_REQUERY_PERIOD
* seconds any more. */
static void
directory_clean_last_hid_serv_requests(time_t now)
{
strmap_iter_t *iter;
time_t cutoff = now - REND_HID_SERV_DIR_REQUERY_PERIOD;
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
for (iter = strmap_iter_init(last_hid_serv_requests);
!strmap_iter_done(iter); ) {
const char *key;
void *val;
time_t *ent;
strmap_iter_get(iter, &key, &val);
ent = (time_t *) val;
if (*ent < cutoff) {
iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
tor_free(ent);
} else {
iter = strmap_iter_next(last_hid_serv_requests, iter);
}
}
}
/** Remove all requests related to the hidden service named
* <b>onion_address</b> from the history of times of requests to
* hidden service directories. */
static void
purge_hid_serv_from_last_hid_serv_requests(const char *onion_address)
{
strmap_iter_t *iter;
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
/* XXX023 tor_assert(strlen(onion_address) == REND_SERVICE_ID_LEN_BASE32); */
for (iter = strmap_iter_init(last_hid_serv_requests);
!strmap_iter_done(iter); ) {
const char *key;
void *val;
strmap_iter_get(iter, &key, &val);
/* XXX023 tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */
if (tor_memeq(key + LAST_HID_SERV_REQUEST_KEY_LEN -
REND_SERVICE_ID_LEN_BASE32,
onion_address,
REND_SERVICE_ID_LEN_BASE32)) {
iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
tor_free(val);
} else {
iter = strmap_iter_next(last_hid_serv_requests, iter);
}
}
}
/** Purge the history of request times to hidden service directories,
* so that future lookups of an HS descriptor will not fail because we
* accessed all of the HSDir relays responsible for the descriptor
* recently. */
void
rend_client_purge_last_hid_serv_requests(void)
{
/* Don't create the table if it doesn't exist yet (and it may very
* well not exist if the user hasn't accessed any HSes)... */
strmap_t *old_last_hid_serv_requests = last_hid_serv_requests_;
/* ... and let get_last_hid_serv_requests re-create it for us if
* necessary. */
last_hid_serv_requests_ = NULL;
if (old_last_hid_serv_requests != NULL) {
log_info(LD_REND, "Purging client last-HS-desc-request-time table");
strmap_free(old_last_hid_serv_requests, tor_free_);
}
}
/** Determine the responsible hidden service directories for <b>desc_id</b>
* and fetch the descriptor with that ID from one of them. Only
* send a request to a hidden service directory that we have not yet tried
* during this attempt to connect to this hidden service; on success, return 1,
* in the case that no hidden service directory is left to ask for the
* descriptor, return 0, and in case of a failure -1. */
static int
directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query)
{
smartlist_t *responsible_dirs = smartlist_new();
smartlist_t *usable_responsible_dirs = smartlist_new();
const or_options_t *options = get_options();
routerstatus_t *hs_dir;
char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
time_t now = time(NULL);
char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64];
const int tor2web_mode = options->Tor2webMode;
int excluded_some;
tor_assert(desc_id);
tor_assert(rend_query);
/* Determine responsible dirs. Even if we can't get all we want,
* work with the ones we have. If it's empty, we'll notice below. */
hid_serv_get_responsible_directories(responsible_dirs, desc_id);
base32_encode(desc_id_base32, sizeof(desc_id_base32),
desc_id, DIGEST_LEN);
/* Only select those hidden service directories to which we did not send
* a request recently and for which we have a router descriptor here. */
/* Clean request history first. */
directory_clean_last_hid_serv_requests(now);
SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, {
time_t last = lookup_last_hid_serv_request(
dir, desc_id_base32, rend_query, 0, 0);
const node_t *node = node_get_by_id(dir->identity_digest);
if (last + REND_HID_SERV_DIR_REQUERY_PERIOD >= now ||
!node || !node_has_descriptor(node)) {
SMARTLIST_DEL_CURRENT(responsible_dirs, dir);
continue;
}
if (! routerset_contains_node(options->ExcludeNodes, node)) {
smartlist_add(usable_responsible_dirs, dir);
}
});
excluded_some =
smartlist_len(usable_responsible_dirs) < smartlist_len(responsible_dirs);
hs_dir = smartlist_choose(usable_responsible_dirs);
if (! hs_dir && ! options->StrictNodes)
hs_dir = smartlist_choose(responsible_dirs);
smartlist_free(responsible_dirs);
smartlist_free(usable_responsible_dirs);
if (!hs_dir) {
log_info(LD_REND, "Could not pick one of the responsible hidden "
"service directories, because we requested them all "
"recently without success.");
if (options->StrictNodes && excluded_some) {
log_info(LD_REND, "There are others that we could have tried, but "
"they are all excluded, and StrictNodes is set.");
}
return 0;
}
/* Remember that we are requesting a descriptor from this hidden service
* directory now. */
lookup_last_hid_serv_request(hs_dir, desc_id_base32, rend_query, now, 1);
/* Encode descriptor cookie for logging purposes. */
if (rend_query->auth_type != REND_NO_AUTH) {
if (base64_encode(descriptor_cookie_base64,
sizeof(descriptor_cookie_base64),
rend_query->descriptor_cookie, REND_DESC_COOKIE_LEN)<0) {
log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
return 0;
}
/* Remove == signs and newline. */
descriptor_cookie_base64[strlen(descriptor_cookie_base64)-3] = '\0';
} else {
strlcpy(descriptor_cookie_base64, "(none)",
sizeof(descriptor_cookie_base64));
}
/* Send fetch request. (Pass query and possibly descriptor cookie so that
* they can be written to the directory connection and be referred to when
* the response arrives. */
directory_initiate_command_routerstatus_rend(hs_dir,
DIR_PURPOSE_FETCH_RENDDESC_V2,
ROUTER_PURPOSE_GENERAL,
tor2web_mode?DIRIND_ONEHOP:DIRIND_ANONYMOUS,
desc_id_base32,
NULL, 0, 0,
rend_query);
log_info(LD_REND, "Sending fetch request for v2 descriptor for "
"service '%s' with descriptor ID '%s', auth type %d, "
"and descriptor cookie '%s' to hidden service "
"directory %s",
rend_query->onion_address, desc_id_base32,
rend_query->auth_type,
(rend_query->auth_type == REND_NO_AUTH ? "[none]" :
escaped_safe_str_client(descriptor_cookie_base64)),
routerstatus_describe(hs_dir));
control_event_hs_descriptor_requested(rend_query,
hs_dir->identity_digest,
desc_id_base32);
return 1;
}
/** Unless we already have a descriptor for <b>rend_query</b> with at least
* one (possibly) working introduction point in it, start a connection to a
* hidden service directory to fetch a v2 rendezvous service descriptor. */
void
rend_client_refetch_v2_renddesc(const rend_data_t *rend_query)
{
char descriptor_id[DIGEST_LEN];
int replicas_left_to_try[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS];
int i, tries_left;
rend_cache_entry_t *e = NULL;
tor_assert(rend_query);
/* Are we configured to fetch descriptors? */
if (!get_options()->FetchHidServDescriptors) {
log_warn(LD_REND, "We received an onion address for a v2 rendezvous "
"service descriptor, but are not fetching service descriptors.");
return;
}
/* Before fetching, check if we already have a usable descriptor here. */
if (rend_cache_lookup_entry(rend_query->onion_address, -1, &e) > 0 &&
rend_client_any_intro_points_usable(e)) {
log_info(LD_REND, "We would fetch a v2 rendezvous descriptor, but we "
"already have a usable descriptor here. Not fetching.");
return;
}
log_debug(LD_REND, "Fetching v2 rendezvous descriptor for service %s",
safe_str_client(rend_query->onion_address));
/* Randomly iterate over the replicas until a descriptor can be fetched
* from one of the consecutive nodes, or no options are left. */
tries_left = REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS;
for (i = 0; i < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; i++)
replicas_left_to_try[i] = i;
while (tries_left > 0) {
int rand = crypto_rand_int(tries_left);
int chosen_replica = replicas_left_to_try[rand];
replicas_left_to_try[rand] = replicas_left_to_try[--tries_left];
if (rend_compute_v2_desc_id(descriptor_id, rend_query->onion_address,
rend_query->auth_type == REND_STEALTH_AUTH ?
rend_query->descriptor_cookie : NULL,
time(NULL), chosen_replica) < 0) {
log_warn(LD_REND, "Internal error: Computing v2 rendezvous "
"descriptor ID did not succeed.");
/*
* Hmm, can this write anything to descriptor_id and still fail?
* Let's clear it just to be safe.
*
* From here on, any returns should goto done which clears
* descriptor_id so we don't leave key-derived material on the stack.
*/
goto done;
}
if (directory_get_from_hs_dir(descriptor_id, rend_query) != 0)
goto done; /* either success or failure, but we're done */
}
/* If we come here, there are no hidden service directories left. */
log_info(LD_REND, "Could not pick one of the responsible hidden "
"service directories to fetch descriptors, because "
"we already tried them all unsuccessfully.");
/* Close pending connections. */
rend_client_desc_trynow(rend_query->onion_address);
done:
memwipe(descriptor_id, 0, sizeof(descriptor_id));
return;
}
/** Cancel all rendezvous descriptor fetches currently in progress.
*/
void
rend_client_cancel_descriptor_fetches(void)
{
smartlist_t *connection_array = get_connection_array();
SMARTLIST_FOREACH_BEGIN(connection_array, connection_t *, conn) {
if (conn->type == CONN_TYPE_DIR &&
conn->purpose == DIR_PURPOSE_FETCH_RENDDESC_V2) {
/* It's a rendezvous descriptor fetch in progress -- cancel it
* by marking the connection for close.
*
* Even if this connection has already reached EOF, this is
* enough to make sure that if the descriptor hasn't been
* processed yet, it won't be. See the end of
* connection_handle_read; connection_reached_eof (indirectly)
* processes whatever response the connection received. */
const rend_data_t *rd = (TO_DIR_CONN(conn))->rend_data;
if (!rd) {
log_warn(LD_BUG | LD_REND,
"Marking for close dir conn fetching rendezvous "
"descriptor for unknown service!");
} else {
log_debug(LD_REND, "Marking for close dir conn fetching "
"rendezvous descriptor for service %s",
safe_str(rd->onion_address));
}
connection_mark_for_close(conn);
}
} SMARTLIST_FOREACH_END(conn);
}
/** Mark <b>failed_intro</b> as a failed introduction point for the
* hidden service specified by <b>rend_query</b>. If the HS now has no
* usable intro points, or we do not have an HS descriptor for it,
* then launch a new renddesc fetch.
*
* If <b>failure_type</b> is INTRO_POINT_FAILURE_GENERIC, remove the
* intro point from (our parsed copy of) the HS descriptor.
*
* If <b>failure_type</b> is INTRO_POINT_FAILURE_TIMEOUT, mark the
* intro point as 'timed out'; it will not be retried until the
* current hidden service connection attempt has ended or it has
* appeared in a newly fetched rendezvous descriptor.
*
* If <b>failure_type</b> is INTRO_POINT_FAILURE_UNREACHABLE,
* increment the intro point's reachability-failure count; if it has
* now failed MAX_INTRO_POINT_REACHABILITY_FAILURES or more times,
* remove the intro point from (our parsed copy of) the HS descriptor.
*
* Return -1 if error, 0 if no usable intro points remain or service
* unrecognized, 1 if recognized and some intro points remain.
*/
int
rend_client_report_intro_point_failure(extend_info_t *failed_intro,
const rend_data_t *rend_query,
unsigned int failure_type)
{
int i, r;
rend_cache_entry_t *ent;
connection_t *conn;
r = rend_cache_lookup_entry(rend_query->onion_address, -1, &ent);
if (r<0) {
log_warn(LD_BUG, "Malformed service ID %s.",
escaped_safe_str_client(rend_query->onion_address));
return -1;
}
if (r==0) {
log_info(LD_REND, "Unknown service %s. Re-fetching descriptor.",
escaped_safe_str_client(rend_query->onion_address));
rend_client_refetch_v2_renddesc(rend_query);
return 0;
}
for (i = 0; i < smartlist_len(ent->parsed->intro_nodes); i++) {
rend_intro_point_t *intro = smartlist_get(ent->parsed->intro_nodes, i);
if (tor_memeq(failed_intro->identity_digest,
intro->extend_info->identity_digest, DIGEST_LEN)) {
switch (failure_type) {
default:
log_warn(LD_BUG, "Unknown failure type %u. Removing intro point.",
failure_type);
tor_fragile_assert();
/* fall through */
case INTRO_POINT_FAILURE_GENERIC:
rend_intro_point_free(intro);
smartlist_del(ent->parsed->intro_nodes, i);
break;
case INTRO_POINT_FAILURE_TIMEOUT:
intro->timed_out = 1;
break;
case INTRO_POINT_FAILURE_UNREACHABLE:
++(intro->unreachable_count);
{
int zap_intro_point =
intro->unreachable_count >= MAX_INTRO_POINT_REACHABILITY_FAILURES;
log_info(LD_REND, "Failed to reach this intro point %u times.%s",
intro->unreachable_count,
zap_intro_point ? " Removing from descriptor.": "");
if (zap_intro_point) {
rend_intro_point_free(intro);
smartlist_del(ent->parsed->intro_nodes, i);
}
}
break;
}
break;
}
}
if (! rend_client_any_intro_points_usable(ent)) {
log_info(LD_REND,
"No more intro points remain for %s. Re-fetching descriptor.",
escaped_safe_str_client(rend_query->onion_address));
rend_client_refetch_v2_renddesc(rend_query);
/* move all pending streams back to renddesc_wait */
while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP,
AP_CONN_STATE_CIRCUIT_WAIT,
rend_query->onion_address))) {
conn->state = AP_CONN_STATE_RENDDESC_WAIT;
}
return 0;
}
log_info(LD_REND,"%d options left for %s.",
smartlist_len(ent->parsed->intro_nodes),
escaped_safe_str_client(rend_query->onion_address));
return 1;
}
/** Called when we receive a RENDEZVOUS_ESTABLISHED cell; changes the state of
* the circuit to C_REND_READY.
*/
int
rend_client_rendezvous_acked(origin_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
(void) request;
(void) request_len;
/* we just got an ack for our establish-rendezvous. switch purposes. */
if (circ->base_.purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND) {
log_warn(LD_PROTOCOL,"Got a rendezvous ack when we weren't expecting one. "
"Closing circ.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
log_info(LD_REND,"Got rendezvous ack. This circuit is now ready for "
"rendezvous.");
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_REND_READY);
/* Set timestamp_dirty, because circuit_expire_building expects it
* to specify when a circuit entered the _C_REND_READY state. */
circ->base_.timestamp_dirty = time(NULL);
/* From a path bias point of view, this circuit is now successfully used.
* Waiting any longer opens us up to attacks from Bob. He could induce
* Alice to attempt to connect to his hidden service and never reply
* to her rend requests */
pathbias_mark_use_success(circ);
/* XXXX This is a pretty brute-force approach. It'd be better to
* attach only the connections that are waiting on this circuit, rather
* than trying to attach them all. See comments bug 743. */
/* If we already have the introduction circuit built, make sure we send
* the INTRODUCE cell _now_ */
connection_ap_attach_pending();
return 0;
}
/** Bob sent us a rendezvous cell; join the circuits. */
int
rend_client_receive_rendezvous(origin_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
crypt_path_t *hop;
char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN];
if ((circ->base_.purpose != CIRCUIT_PURPOSE_C_REND_READY &&
circ->base_.purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)
|| !circ->build_state->pending_final_cpath) {
log_warn(LD_PROTOCOL,"Got rendezvous2 cell from hidden service, but not "
"expecting it. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
if (request_len != DH_KEY_LEN+DIGEST_LEN) {
log_warn(LD_PROTOCOL,"Incorrect length (%d) on RENDEZVOUS2 cell.",
(int)request_len);
goto err;
}
log_info(LD_REND,"Got RENDEZVOUS2 cell from hidden service.");
/* first DH_KEY_LEN bytes are g^y from bob. Finish the dh handshake...*/
tor_assert(circ->build_state);
tor_assert(circ->build_state->pending_final_cpath);
hop = circ->build_state->pending_final_cpath;
tor_assert(hop->rend_dh_handshake_state);
if (crypto_dh_compute_secret(LOG_PROTOCOL_WARN,
hop->rend_dh_handshake_state, (char*)request,
DH_KEY_LEN,
keys, DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
log_warn(LD_GENERAL, "Couldn't complete DH handshake.");
goto err;
}
/* ... and set up cpath. */
if (circuit_init_cpath_crypto(hop, keys+DIGEST_LEN, 0)<0)
goto err;
/* Check whether the digest is right... */
if (tor_memneq(keys, request+DH_KEY_LEN, DIGEST_LEN)) {
log_warn(LD_PROTOCOL, "Incorrect digest of key material.");
goto err;
}
crypto_dh_free(hop->rend_dh_handshake_state);
hop->rend_dh_handshake_state = NULL;
/* All is well. Extend the circuit. */
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_REND_JOINED);
hop->state = CPATH_STATE_OPEN;
/* set the windows to default. these are the windows
* that alice thinks bob has.
*/
hop->package_window = circuit_initial_package_window();
hop->deliver_window = CIRCWINDOW_START;
/* Now that this circuit has finished connecting to its destination,
* make sure circuit_get_open_circ_or_launch is willing to return it
* so we can actually use it. */
circ->hs_circ_has_timed_out = 0;
onion_append_to_cpath(&circ->cpath, hop);
circ->build_state->pending_final_cpath = NULL; /* prevent double-free */
circuit_try_attaching_streams(circ);
memwipe(keys, 0, sizeof(keys));
return 0;
err:
memwipe(keys, 0, sizeof(keys));
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
/** Find all the apconns in state AP_CONN_STATE_RENDDESC_WAIT that are
* waiting on <b>query</b>. If there's a working cache entry here with at
* least one intro point, move them to the next state. */
void
rend_client_desc_trynow(const char *query)
{
entry_connection_t *conn;
rend_cache_entry_t *entry;
const rend_data_t *rend_data;
time_t now = time(NULL);
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
if (base_conn->type != CONN_TYPE_AP ||
base_conn->state != AP_CONN_STATE_RENDDESC_WAIT ||
base_conn->marked_for_close)
continue;
conn = TO_ENTRY_CONN(base_conn);
rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data;
if (!rend_data)
continue;
if (rend_cmp_service_ids(query, rend_data->onion_address))
continue;
assert_connection_ok(base_conn, now);
if (rend_cache_lookup_entry(rend_data->onion_address, -1,
&entry) == 1 &&
rend_client_any_intro_points_usable(entry)) {
/* either this fetch worked, or it failed but there was a
* valid entry from before which we should reuse */
log_info(LD_REND,"Rend desc is usable. Launching circuits.");
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
/* restart their timeout values, so they get a fair shake at
* connecting to the hidden service. */
base_conn->timestamp_created = now;
base_conn->timestamp_lastread = now;
base_conn->timestamp_lastwritten = now;
if (connection_ap_handshake_attach_circuit(conn) < 0) {
/* it will never work */
log_warn(LD_REND,"Rendezvous attempt failed. Closing.");
if (!base_conn->marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
}
} else { /* 404, or fetch didn't get that far */
log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
"unavailable (try again later).",
safe_str_client(query));
connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED);
rend_client_note_connection_attempt_ended(query);
}
} SMARTLIST_FOREACH_END(base_conn);
}
/** Clear temporary state used only during an attempt to connect to
* the hidden service named <b>onion_address</b>. Called when a
* connection attempt has ended; may be called occasionally at other
* times, and should be reasonably harmless. */
void
rend_client_note_connection_attempt_ended(const char *onion_address)
{
rend_cache_entry_t *cache_entry = NULL;
rend_cache_lookup_entry(onion_address, -1, &cache_entry);
log_info(LD_REND, "Connection attempt for %s has ended; "
"cleaning up temporary state.",
safe_str_client(onion_address));
/* Clear the timed_out flag on all remaining intro points for this HS. */
if (cache_entry != NULL) {
SMARTLIST_FOREACH(cache_entry->parsed->intro_nodes,
rend_intro_point_t *, ip,
ip->timed_out = 0; );
}
/* Remove the HS's entries in last_hid_serv_requests. */
purge_hid_serv_from_last_hid_serv_requests(onion_address);
}
/** Return a newly allocated extend_info_t* for a randomly chosen introduction
* point for the named hidden service. Return NULL if all introduction points
* have been tried and failed.
*/
extend_info_t *
rend_client_get_random_intro(const rend_data_t *rend_query)
{
extend_info_t *result;
rend_cache_entry_t *entry;
if (rend_cache_lookup_entry(rend_query->onion_address, -1, &entry) < 1) {
log_warn(LD_REND,
"Query '%s' didn't have valid rend desc in cache. Failing.",
safe_str_client(rend_query->onion_address));
return NULL;
}
/* See if we can get a node that complies with ExcludeNodes */
if ((result = rend_client_get_random_intro_impl(entry, 1, 1)))
return result;
/* If not, and StrictNodes is not set, see if we can return any old node
*/
if (!get_options()->StrictNodes)
return rend_client_get_random_intro_impl(entry, 0, 1);
return NULL;
}
/** As rend_client_get_random_intro, except assume that StrictNodes is set
* iff <b>strict</b> is true. If <b>warnings</b> is false, don't complain
* to the user when we're out of nodes, even if StrictNodes is true.
*/
static extend_info_t *
rend_client_get_random_intro_impl(const rend_cache_entry_t *entry,
const int strict,
const int warnings)
{
int i;
rend_intro_point_t *intro;
const or_options_t *options = get_options();
smartlist_t *usable_nodes;
int n_excluded = 0;
/* We'll keep a separate list of the usable nodes. If this becomes empty,
* no nodes are usable. */
usable_nodes = smartlist_new();
smartlist_add_all(usable_nodes, entry->parsed->intro_nodes);
/* Remove the intro points that have timed out during this HS
* connection attempt from our list of usable nodes. */
SMARTLIST_FOREACH(usable_nodes, rend_intro_point_t *, ip,
if (ip->timed_out) {
SMARTLIST_DEL_CURRENT(usable_nodes, ip);
});
again:
if (smartlist_len(usable_nodes) == 0) {
if (n_excluded && get_options()->StrictNodes && warnings) {
/* We only want to warn if StrictNodes is really set. Otherwise
* we're just about to retry anyways.
*/
log_warn(LD_REND, "All introduction points for hidden service are "
"at excluded relays, and StrictNodes is set. Skipping.");
}
smartlist_free(usable_nodes);
return NULL;
}
i = crypto_rand_int(smartlist_len(usable_nodes));
intro = smartlist_get(usable_nodes, i);
/* Do we need to look up the router or is the extend info complete? */
if (!intro->extend_info->onion_key) {
const node_t *node;
extend_info_t *new_extend_info;
if (tor_digest_is_zero(intro->extend_info->identity_digest))
node = node_get_by_hex_id(intro->extend_info->nickname);
else
node = node_get_by_id(intro->extend_info->identity_digest);
if (!node) {
log_info(LD_REND, "Unknown router with nickname '%s'; trying another.",
intro->extend_info->nickname);
smartlist_del(usable_nodes, i);
goto again;
}
new_extend_info = extend_info_from_node(node, 0);
if (!new_extend_info) {
log_info(LD_REND, "We don't have a descriptor for the intro-point relay "
"'%s'; trying another.",
extend_info_describe(intro->extend_info));
smartlist_del(usable_nodes, i);
goto again;
} else {
extend_info_free(intro->extend_info);
intro->extend_info = new_extend_info;
}
tor_assert(intro->extend_info != NULL);
}
/* Check if we should refuse to talk to this router. */
if (strict &&
routerset_contains_extendinfo(options->ExcludeNodes,
intro->extend_info)) {
n_excluded++;
smartlist_del(usable_nodes, i);
goto again;
}
smartlist_free(usable_nodes);
return extend_info_dup(intro->extend_info);
}
/** Return true iff any introduction points still listed in <b>entry</b> are
* usable. */
int
rend_client_any_intro_points_usable(const rend_cache_entry_t *entry)
{
extend_info_t *extend_info =
rend_client_get_random_intro_impl(entry, get_options()->StrictNodes, 0);
int rv = (extend_info != NULL);
extend_info_free(extend_info);
return rv;
}
/** Client-side authorizations for hidden services; map of onion address to
* rend_service_authorization_t*. */
static strmap_t *auth_hid_servs = NULL;
/** Look up the client-side authorization for the hidden service with
* <b>onion_address</b>. Return NULL if no authorization is available for
* that address. */
rend_service_authorization_t*
rend_client_lookup_service_authorization(const char *onion_address)
{
tor_assert(onion_address);
if (!auth_hid_servs) return NULL;
return strmap_get(auth_hid_servs, onion_address);
}
/** Helper: Free storage held by rend_service_authorization_t. */
static void
rend_service_authorization_free(rend_service_authorization_t *auth)
{
tor_free(auth);
}
/** Helper for strmap_free. */
static void
rend_service_authorization_strmap_item_free(void *service_auth)
{
rend_service_authorization_free(service_auth);
}
/** Release all the storage held in auth_hid_servs.
*/
void
rend_service_authorization_free_all(void)
{
if (!auth_hid_servs) {
return;
}
strmap_free(auth_hid_servs, rend_service_authorization_strmap_item_free);
auth_hid_servs = NULL;
}
/** Parse <b>config_line</b> as a client-side authorization for a hidden
* service and add it to the local map of hidden service authorizations.
* Return 0 for success and -1 for failure. */
int
rend_parse_service_authorization(const or_options_t *options,
int validate_only)
{
config_line_t *line;
int res = -1;
strmap_t *parsed = strmap_new();
smartlist_t *sl = smartlist_new();
rend_service_authorization_t *auth = NULL;
char descriptor_cookie_tmp[REND_DESC_COOKIE_LEN+2];
char descriptor_cookie_base64ext[REND_DESC_COOKIE_LEN_BASE64+2+1];
for (line = options->HidServAuth; line; line = line->next) {
char *onion_address, *descriptor_cookie;
int auth_type_val = 0;
auth = NULL;
SMARTLIST_FOREACH(sl, char *, c, tor_free(c););
smartlist_clear(sl);
smartlist_split_string(sl, line->value, " ",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
if (smartlist_len(sl) < 2) {
log_warn(LD_CONFIG, "Configuration line does not consist of "
"\"onion-address authorization-cookie [service-name]\": "
"'%s'", line->value);
goto err;
}
auth = tor_malloc_zero(sizeof(rend_service_authorization_t));
/* Parse onion address. */
onion_address = smartlist_get(sl, 0);
if (strlen(onion_address) != REND_SERVICE_ADDRESS_LEN ||
strcmpend(onion_address, ".onion")) {
log_warn(LD_CONFIG, "Onion address has wrong format: '%s'",
onion_address);
goto err;
}
strlcpy(auth->onion_address, onion_address, REND_SERVICE_ID_LEN_BASE32+1);
if (!rend_valid_service_id(auth->onion_address)) {
log_warn(LD_CONFIG, "Onion address has wrong format: '%s'",
onion_address);
goto err;
}
/* Parse descriptor cookie. */
descriptor_cookie = smartlist_get(sl, 1);
if (strlen(descriptor_cookie) != REND_DESC_COOKIE_LEN_BASE64) {
log_warn(LD_CONFIG, "Authorization cookie has wrong length: '%s'",
descriptor_cookie);
goto err;
}
/* Add trailing zero bytes (AA) to make base64-decoding happy. */
tor_snprintf(descriptor_cookie_base64ext,
REND_DESC_COOKIE_LEN_BASE64+2+1,
"%sAA", descriptor_cookie);
if (base64_decode(descriptor_cookie_tmp, sizeof(descriptor_cookie_tmp),
descriptor_cookie_base64ext,
strlen(descriptor_cookie_base64ext)) < 0) {
log_warn(LD_CONFIG, "Decoding authorization cookie failed: '%s'",
descriptor_cookie);
goto err;
}
auth_type_val = (((uint8_t)descriptor_cookie_tmp[16]) >> 4) + 1;
if (auth_type_val < 1 || auth_type_val > 2) {
log_warn(LD_CONFIG, "Authorization cookie has unknown authorization "
"type encoded.");
goto err;
}
auth->auth_type = auth_type_val == 1 ? REND_BASIC_AUTH : REND_STEALTH_AUTH;
memcpy(auth->descriptor_cookie, descriptor_cookie_tmp,
REND_DESC_COOKIE_LEN);
if (strmap_get(parsed, auth->onion_address)) {
log_warn(LD_CONFIG, "Duplicate authorization for the same hidden "
"service.");
goto err;
}
strmap_set(parsed, auth->onion_address, auth);
auth = NULL;
}
res = 0;
goto done;
err:
res = -1;
done:
rend_service_authorization_free(auth);
SMARTLIST_FOREACH(sl, char *, c, tor_free(c););
smartlist_free(sl);
if (!validate_only && res == 0) {
rend_service_authorization_free_all();
auth_hid_servs = parsed;
} else {
strmap_free(parsed, rend_service_authorization_strmap_item_free);
}
memwipe(descriptor_cookie_tmp, 0, sizeof(descriptor_cookie_tmp));
memwipe(descriptor_cookie_base64ext, 0, sizeof(descriptor_cookie_base64ext));
return res;
}
|