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
|
/*
* onion_client.c -- Implementation of the client part of docs/Prevent_Tracking.txt
* (The part that uses the onion stuff to connect to the friend)
*
* Copyright (C) 2013 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "onion_client.h"
#include "util.h"
#include "LAN_discovery.h"
/* defines for the array size and
timeout for onion announce packets. */
#define ANNOUNCE_ARRAY_SIZE 256
#define ANNOUNCE_TIMEOUT 10
/*
* return -1 if nodes are suitable for creating a new path.
* return path number of already existing similar path if one already exists.
*/
static int is_path_used(Onion_Client_Paths *onion_paths, Node_format *nodes)
{
uint32_t i;
for (i = 0; i < NUMBER_ONION_PATHS; ++i) {
if (is_timeout(onion_paths->last_path_success[i], ONION_PATH_TIMEOUT)) {
continue;
}
if (is_timeout(onion_paths->path_creation_time[i], ONION_PATH_MAX_LIFETIME)) {
continue;
}
if (ipport_equal(&onion_paths->paths[i].ip_port1, &nodes[0].ip_port)) {
return i;
}
}
return -1;
}
/* Create a new path or use an old suitable one (if pathnum is valid)
* or a rondom one from onion_paths.
*
* return -1 on failure
* return 0 on success
*
* TODO: Make this function better, it currently probably is vulnerable to some attacks that
* could de anonimize us.
*/
static int random_path(DHT *dht, Onion_Client_Paths *onion_paths, uint32_t pathnum, Onion_Path *path)
{
if (pathnum >= NUMBER_ONION_PATHS)
pathnum = rand() % NUMBER_ONION_PATHS;
if (is_timeout(onion_paths->last_path_success[pathnum], ONION_PATH_TIMEOUT)
|| is_timeout(onion_paths->path_creation_time[pathnum], ONION_PATH_MAX_LIFETIME)) {
Node_format nodes[3];
if (random_nodes_path(dht, nodes, 3) != 3)
return -1;
int n = is_path_used(onion_paths, nodes);
if (n == -1) {
if (create_onion_path(dht, &onion_paths->paths[pathnum], nodes) == -1)
return -1;
onion_paths->last_path_success[pathnum] = unix_time() + ONION_PATH_FIRST_TIMEOUT - ONION_PATH_TIMEOUT;
onion_paths->path_creation_time[pathnum] = unix_time();
} else {
pathnum = n;
}
}
memcpy(path, &onion_paths->paths[pathnum], sizeof(Onion_Path));
return 0;
}
/* Set path timeouts, return the path number.
*
*/
static uint32_t set_path_timeouts(Onion_Client *onion_c, uint32_t num, IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
Onion_Client_Paths *onion_paths;
if (num == 0) {
onion_paths = &onion_c->onion_paths;
} else {
onion_paths = &onion_c->friends_list[num - 1].onion_paths;
}
uint32_t i;
for (i = 0; i < NUMBER_ONION_PATHS; ++i) {
if (ipport_equal(&onion_paths->paths[i].ip_port1, &source)) {
onion_paths->last_path_success[i] = unix_time();
return i;
}
}
return ~0;
}
/* Creates a sendback for use in an announce request.
*
* num is 0 if we used our secret public key for the announce
* num is 1 + friendnum if we use a temporary one.
*
* Public key is the key we will be sending it to.
* ip_port is the ip_port of the node we will be sending
* it to.
*
* sendback must be at least ONION_ANNOUNCE_SENDBACK_DATA_LENGTH big
*
* return -1 on failure
* return 0 on success
*
*/
static int new_sendback(Onion_Client *onion_c, uint32_t num, uint8_t *public_key, IP_Port ip_port, uint64_t *sendback)
{
uint8_t data[sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES + sizeof(IP_Port)];
memcpy(data, &num, sizeof(uint32_t));
memcpy(data + sizeof(uint32_t), public_key, crypto_box_PUBLICKEYBYTES);
memcpy(data + sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES, &ip_port, sizeof(IP_Port));
*sendback = ping_array_add(&onion_c->announce_ping_array, data, sizeof(data));
if (*sendback == 0)
return -1;
return 0;
}
/* Checks if the sendback is valid and returns the public key contained in it in ret_pubkey and the
* ip contained in it in ret_ip_port
*
* sendback is the sendback ONION_ANNOUNCE_SENDBACK_DATA_LENGTH big
* ret_pubkey must be at least crypto_box_PUBLICKEYBYTES big
* ret_ip_port must be at least 1 big
*
* return ~0 on failure
* return num (see new_sendback(...)) on success
*/
static uint32_t check_sendback(Onion_Client *onion_c, uint8_t *sendback, uint8_t *ret_pubkey, IP_Port *ret_ip_port)
{
uint64_t sback;
memcpy(&sback, sendback, sizeof(uint64_t));
uint8_t data[sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES + sizeof(IP_Port)];
if (ping_array_check(data, sizeof(data), &onion_c->announce_ping_array, sback) != sizeof(data))
return ~0;
memcpy(ret_pubkey, data + sizeof(uint32_t), crypto_box_PUBLICKEYBYTES);
memcpy(ret_ip_port, data + sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES, sizeof(IP_Port));
uint32_t num;
memcpy(&num, data, sizeof(uint32_t));
return num;
}
static int client_send_announce_request(Onion_Client *onion_c, uint32_t num, IP_Port dest, uint8_t *dest_pubkey,
uint8_t *ping_id, uint32_t pathnum)
{
if (num > onion_c->num_friends)
return -1;
uint64_t sendback;
if (new_sendback(onion_c, num, dest_pubkey, dest, &sendback) == -1)
return -1;
uint8_t zero_ping_id[ONION_PING_ID_SIZE] = {0};
if (ping_id == NULL)
ping_id = zero_ping_id;
Onion_Path path;
Node_format dest_node;
dest_node.ip_port = dest;
memcpy(dest_node.client_id, dest_pubkey, crypto_box_PUBLICKEYBYTES);
if (num == 0) {
if (random_path(onion_c->dht, &onion_c->onion_paths, pathnum, &path) == -1)
return -1;
return send_announce_request(onion_c->net, &path, dest_node, onion_c->c->self_public_key,
onion_c->c->self_secret_key, ping_id,
onion_c->c->self_public_key, onion_c->temp_public_key, sendback);
} else {
if (random_path(onion_c->dht, &onion_c->friends_list[num - 1].onion_paths, pathnum, &path) == -1)
return -1;
return send_announce_request(onion_c->net, &path, dest_node, onion_c->friends_list[num - 1].temp_public_key,
onion_c->friends_list[num - 1].temp_secret_key, ping_id,
onion_c->friends_list[num - 1].real_client_id, zero_ping_id, sendback);
}
}
static uint8_t cmp_public_key[crypto_box_PUBLICKEYBYTES];
static int cmp_entry(const void *a, const void *b)
{
Onion_Node entry1, entry2;
memcpy(&entry1, a, sizeof(Onion_Node));
memcpy(&entry2, b, sizeof(Onion_Node));
int t1 = is_timeout(entry1.timestamp, ONION_NODE_TIMEOUT);
int t2 = is_timeout(entry2.timestamp, ONION_NODE_TIMEOUT);
if (t1 && t2)
return 0;
if (t1)
return -1;
if (t2)
return 1;
int close = id_closest(cmp_public_key, entry1.client_id, entry2.client_id);
if (close == 1)
return 1;
if (close == 2)
return -1;
return 0;
}
static int client_add_to_list(Onion_Client *onion_c, uint32_t num, uint8_t *public_key, IP_Port ip_port,
uint8_t is_stored, uint8_t *pingid_or_key, IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
Onion_Node *list_nodes = NULL;
uint8_t *reference_id = NULL;
if (num == 0) {
list_nodes = onion_c->clients_announce_list;
reference_id = onion_c->c->self_public_key;
if (is_stored && memcmp(pingid_or_key, onion_c->temp_public_key, crypto_box_PUBLICKEYBYTES) != 0) {
is_stored = 0;
}
} else {
list_nodes = onion_c->friends_list[num - 1].clients_list;
reference_id = onion_c->friends_list[num - 1].real_client_id;
}
memcpy(cmp_public_key, reference_id, crypto_box_PUBLICKEYBYTES);
qsort(list_nodes, MAX_ONION_CLIENTS, sizeof(Onion_Node), cmp_entry);
int index = -1;
uint32_t i;
if (is_timeout(list_nodes[0].timestamp, ONION_NODE_TIMEOUT)
|| id_closest(reference_id, list_nodes[0].client_id, public_key) == 2) {
index = 0;
}
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (memcmp(list_nodes[i].client_id, public_key, crypto_box_PUBLICKEYBYTES) == 0) {
index = i;
break;
}
}
if (index == -1)
return 0;
memcpy(list_nodes[index].client_id, public_key, CLIENT_ID_SIZE);
list_nodes[index].ip_port = ip_port;
if (is_stored) {
memcpy(list_nodes[index].data_public_key, pingid_or_key, crypto_box_PUBLICKEYBYTES);
} else {
memcpy(list_nodes[index].ping_id, pingid_or_key, ONION_PING_ID_SIZE);
}
list_nodes[index].is_stored = is_stored;
list_nodes[index].timestamp = unix_time();
list_nodes[index].last_pinged = 0;
list_nodes[index].path_used = set_path_timeouts(onion_c, num, source);
return 0;
}
static int good_to_ping(Last_Pinged *last_pinged, uint8_t *last_pinged_index, uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < MAX_STORED_PINGED_NODES; ++i) {
if (!is_timeout(last_pinged[i].timestamp, MIN_NODE_PING_TIME))
if (memcmp(last_pinged[i].client_id, client_id, crypto_box_PUBLICKEYBYTES) == 0)
return 0;
}
memcpy(last_pinged[*last_pinged_index % MAX_STORED_PINGED_NODES].client_id, client_id, crypto_box_PUBLICKEYBYTES);
last_pinged[*last_pinged_index % MAX_STORED_PINGED_NODES].timestamp = unix_time();
++*last_pinged_index;
return 1;
}
static int client_ping_nodes(Onion_Client *onion_c, uint32_t num, Node_format *nodes, uint16_t num_nodes,
IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
if (num_nodes == 0)
return 0;
Onion_Node *list_nodes = NULL;
uint8_t *reference_id = NULL;
uint32_t *ping_nodes_sent_second = NULL;
Last_Pinged *last_pinged = NULL;
uint8_t *last_pinged_index = NULL;
if (num == 0) {
list_nodes = onion_c->clients_announce_list;
reference_id = onion_c->c->self_public_key;
ping_nodes_sent_second = &onion_c->ping_nodes_sent_second;
last_pinged = onion_c->last_pinged;
last_pinged_index = &onion_c->last_pinged_index;
} else {
list_nodes = onion_c->friends_list[num - 1].clients_list;
reference_id = onion_c->friends_list[num - 1].real_client_id;
ping_nodes_sent_second = &onion_c->friends_list[num - 1].ping_nodes_sent_second;
last_pinged = onion_c->friends_list[num - 1].last_pinged;
last_pinged_index = &onion_c->friends_list[num - 1].last_pinged_index;
}
uint32_t i, j;
int lan_ips_accepted = (LAN_ip(source.ip) == 0);
for (i = 0; i < num_nodes; ++i) {
if (*ping_nodes_sent_second > MAX_PING_NODES_SECOND_PEER)
return 0;
if (!lan_ips_accepted)
if (LAN_ip(nodes[i].ip_port.ip) == 0)
continue;
if (is_timeout(list_nodes[0].timestamp, ONION_NODE_TIMEOUT)
|| id_closest(reference_id, list_nodes[0].client_id, nodes[i].client_id) == 2) {
/* check if node is already in list. */
for (j = 0; j < MAX_ONION_CLIENTS; ++j) {
if (memcmp(list_nodes[j].client_id, nodes[i].client_id, crypto_box_PUBLICKEYBYTES) == 0) {
break;
}
}
if (j == MAX_ONION_CLIENTS && good_to_ping(last_pinged, last_pinged_index, nodes[i].client_id)) {
if (client_send_announce_request(onion_c, num, nodes[i].ip_port, nodes[i].client_id, NULL, ~0) == 0)
++*ping_nodes_sent_second;
}
}
}
return 0;
}
static int handle_announce_response(void *object, IP_Port source, uint8_t *packet, uint32_t length)
{
Onion_Client *onion_c = object;
if (length < ONION_ANNOUNCE_RESPONSE_MIN_SIZE || length > ONION_ANNOUNCE_RESPONSE_MAX_SIZE)
return 1;
uint16_t len_nodes = length - ONION_ANNOUNCE_RESPONSE_MIN_SIZE;
uint8_t public_key[crypto_box_PUBLICKEYBYTES];
IP_Port ip_port;
uint32_t num = check_sendback(onion_c, packet + 1, public_key, &ip_port);
if (num > onion_c->num_friends)
return 1;
uint8_t plain[1 + ONION_PING_ID_SIZE + len_nodes];
int len = -1;
if (num == 0) {
len = decrypt_data(public_key, onion_c->c->self_secret_key, packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES,
length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES), plain);
} else {
if (onion_c->friends_list[num - 1].status == 0)
return 1;
len = decrypt_data(public_key, onion_c->friends_list[num - 1].temp_secret_key,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES,
length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES), plain);
}
if ((uint32_t)len != sizeof(plain))
return 1;
if (client_add_to_list(onion_c, num, public_key, ip_port, plain[0], plain + 1, source) == -1)
return 1;
if (len_nodes != 0) {
Node_format nodes[MAX_SENT_NODES];
int num_nodes = unpack_nodes(nodes, MAX_SENT_NODES, 0, plain + 1 + ONION_PING_ID_SIZE, len_nodes, 0);
if (num_nodes <= 0)
return 1;
if (client_ping_nodes(onion_c, num, nodes, num_nodes, source) == -1)
return 1;
}
return 0;
}
#define DATA_IN_RESPONSE_MIN_SIZE ONION_DATA_IN_RESPONSE_MIN_SIZE
static int handle_data_response(void *object, IP_Port source, uint8_t *packet, uint32_t length)
{
Onion_Client *onion_c = object;
if (length <= (ONION_DATA_RESPONSE_MIN_SIZE + DATA_IN_RESPONSE_MIN_SIZE))
return 1;
if (length > MAX_DATA_REQUEST_SIZE)
return 1;
uint8_t temp_plain[length - ONION_DATA_RESPONSE_MIN_SIZE];
int len = decrypt_data(packet + 1 + crypto_box_NONCEBYTES, onion_c->temp_secret_key, packet + 1,
packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES,
length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES), temp_plain);
if ((uint32_t)len != sizeof(temp_plain))
return 1;
uint8_t plain[sizeof(temp_plain) - DATA_IN_RESPONSE_MIN_SIZE];
len = decrypt_data(temp_plain, onion_c->c->self_secret_key, packet + 1, temp_plain + crypto_box_PUBLICKEYBYTES,
sizeof(temp_plain) - crypto_box_PUBLICKEYBYTES, plain);
if ((uint32_t)len != sizeof(plain))
return 1;
if (!onion_c->Onion_Data_Handlers[plain[0]].function)
return 1;
return onion_c->Onion_Data_Handlers[plain[0]].function(onion_c->Onion_Data_Handlers[plain[0]].object, temp_plain, plain,
sizeof(plain));
}
#define FAKEID_DATA_ID 156
#define FAKEID_DATA_MIN_LENGTH (1 + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES)
#define FAKEID_DATA_MAX_LENGTH (FAKEID_DATA_MIN_LENGTH + sizeof(Node_format)*MAX_SENT_NODES)
static int handle_fakeid_announce(void *object, uint8_t *source_pubkey, uint8_t *data, uint32_t length)
{
Onion_Client *onion_c = object;
if (length < FAKEID_DATA_MIN_LENGTH)
return 1;
if (length > FAKEID_DATA_MAX_LENGTH)
return 1;
int friend_num = onion_friend_num(onion_c, source_pubkey);
if (friend_num == -1)
return 1;
uint64_t no_replay;
net_to_host(data + 1, sizeof(no_replay));
memcpy(&no_replay, data + 1, sizeof(uint64_t));
if (no_replay <= onion_c->friends_list[friend_num].last_noreplay)
return 1;
onion_c->friends_list[friend_num].last_noreplay = no_replay;
if (memcmp(data + 1 + sizeof(uint64_t), onion_c->friends_list[friend_num].fake_client_id,
crypto_box_PUBLICKEYBYTES) != 0) {
DHT_delfriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id);
onion_c->friends_list[friend_num].last_seen = unix_time();
if (DHT_addfriend(onion_c->dht, data + 1 + sizeof(uint64_t)) == 1) {
return 1;
}
onion_c->friends_list[friend_num].is_fake_clientid = 1;
memcpy(onion_c->friends_list[friend_num].fake_client_id, data + 1 + sizeof(uint64_t), crypto_box_PUBLICKEYBYTES);
}
uint16_t len_nodes = length - FAKEID_DATA_MIN_LENGTH;
if (len_nodes != 0) {
Node_format nodes[MAX_SENT_NODES];
int num_nodes = unpack_nodes(nodes, MAX_SENT_NODES, 0, data + 1 + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES,
len_nodes, 0);
if (num_nodes <= 0)
return 1;
int i;
for (i = 0; i < num_nodes; ++i) {
DHT_getnodes(onion_c->dht, &nodes[i].ip_port, nodes[i].client_id, onion_c->friends_list[friend_num].fake_client_id);
}
}
return 0;
}
/* Send data of length length to friendnum.
* This data will be received by the friend using the Onion_Data_Handlers callbacks.
*
* Even if this function succeeds, the friend might not receive any data.
*
* return the number of packets sent on success
* return -1 on failure.
*/
int send_onion_data(Onion_Client *onion_c, int friend_num, uint8_t *data, uint32_t length)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (length + DATA_IN_RESPONSE_MIN_SIZE > MAX_DATA_REQUEST_SIZE)
return -1;
if (length == 0)
return -1;
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
uint8_t packet[DATA_IN_RESPONSE_MIN_SIZE + length];
memcpy(packet, onion_c->c->self_public_key, crypto_box_PUBLICKEYBYTES);
int len = encrypt_data(onion_c->friends_list[friend_num].real_client_id, onion_c->c->self_secret_key, nonce, data,
length, packet + crypto_box_PUBLICKEYBYTES);
if ((uint32_t)len + crypto_box_PUBLICKEYBYTES != sizeof(packet))
return -1;
uint32_t i, good_nodes[MAX_ONION_CLIENTS], num_good = 0, num_nodes = 0;
Onion_Path path[MAX_ONION_CLIENTS];
Onion_Node *list_nodes = onion_c->friends_list[friend_num].clients_list;
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++num_nodes;
if (list_nodes[i].is_stored) {
if (random_path(onion_c->dht, &onion_c->friends_list[friend_num].onion_paths, ~0, &path[num_good]) == -1)
continue;
good_nodes[num_good] = i;
++num_good;
}
}
if (num_good < (num_nodes / 4) + 1)
return -1;
uint32_t good = 0;
for (i = 0; i < num_good; ++i) {
if (send_data_request(onion_c->net, &path[i], list_nodes[good_nodes[i]].ip_port,
onion_c->friends_list[friend_num].real_client_id, list_nodes[good_nodes[i]].data_public_key, nonce, packet,
sizeof(packet)) == 0)
++good;
}
return good;
}
/* Try to send the fakeid via the DHT instead of onion
*
* Even if this function succeeds, the friend might not receive any data.
*
* return the number of packets sent on success
* return -1 on failure.
*/
static int send_dht_fakeid(Onion_Client *onion_c, int friend_num, uint8_t *data, uint32_t length)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (!onion_c->friends_list[friend_num].is_fake_clientid)
return -1;
uint8_t nonce[crypto_box_NONCEBYTES];
new_nonce(nonce);
uint8_t temp[DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES + length];
memcpy(temp, onion_c->c->self_public_key, crypto_box_PUBLICKEYBYTES);
memcpy(temp + crypto_box_PUBLICKEYBYTES, nonce, crypto_box_NONCEBYTES);
int len = encrypt_data(onion_c->friends_list[friend_num].real_client_id, onion_c->c->self_secret_key, nonce, data,
length, temp + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES);
if ((uint32_t)len + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES != sizeof(temp))
return -1;
uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
len = create_request(onion_c->dht->self_public_key, onion_c->dht->self_secret_key, packet,
onion_c->friends_list[friend_num].fake_client_id, temp, sizeof(temp), FAKEID_DATA_ID);
if (len == -1)
return -1;
return route_tofriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id, packet, len);
}
static int handle_dht_fakeid(void *object, IP_Port source, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
{
Onion_Client *onion_c = object;
if (length < FAKEID_DATA_MIN_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES)
return 1;
if (length > FAKEID_DATA_MAX_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES)
return 1;
uint8_t plain[FAKEID_DATA_MAX_LENGTH];
int len = decrypt_data(packet, onion_c->c->self_secret_key, packet + crypto_box_PUBLICKEYBYTES,
packet + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES,
length - (crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES), plain);
if ((uint32_t)len != length - (DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES))
return 1;
if (memcmp(source_pubkey, plain + 1 + sizeof(uint64_t), crypto_box_PUBLICKEYBYTES) != 0)
return 1;
return handle_fakeid_announce(onion_c, packet, plain, len);
}
/* Send the packets to tell our friends what our DHT public key is.
*
* if onion_dht_both is 0, use only the onion to send the packet.
* if it is 1, use only the dht.
* if it is something else, use both.
*
* return the number of packets sent on success
* return -1 on failure.
*/
static int send_fakeid_announce(Onion_Client *onion_c, uint16_t friend_num, uint8_t onion_dht_both)
{
if (friend_num >= onion_c->num_friends)
return -1;
uint8_t data[FAKEID_DATA_MAX_LENGTH];
data[0] = FAKEID_DATA_ID;
uint64_t no_replay = unix_time();
host_to_net((uint8_t *)&no_replay, sizeof(no_replay));
memcpy(data + 1, &no_replay, sizeof(no_replay));
memcpy(data + 1 + sizeof(uint64_t), onion_c->dht->self_public_key, crypto_box_PUBLICKEYBYTES);
Node_format nodes[MAX_SENT_NODES];
uint16_t num_nodes = closelist_nodes(onion_c->dht, nodes, MAX_SENT_NODES);
int nodes_len = 0;
if (num_nodes != 0) {
nodes_len = pack_nodes(data + FAKEID_DATA_MIN_LENGTH, FAKEID_DATA_MAX_LENGTH - FAKEID_DATA_MIN_LENGTH, nodes,
num_nodes);
if (nodes_len <= 0)
return -1;
}
int num1 = -1, num2 = -1;
if (onion_dht_both != 1)
num1 = send_onion_data(onion_c, friend_num, data, FAKEID_DATA_MIN_LENGTH + nodes_len);
if (onion_dht_both != 0)
num2 = send_dht_fakeid(onion_c, friend_num, data, FAKEID_DATA_MIN_LENGTH + nodes_len);
if (num1 == -1)
return num2;
if (num2 == -1)
return num1;
return num1 + num2;
}
/* Get the friend_num of a friend.
*
* return -1 on failure.
* return friend number on success.
*/
int onion_friend_num(Onion_Client *onion_c, uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < onion_c->num_friends; ++i) {
if (onion_c->friends_list[i].status == 0)
continue;
if (memcmp(client_id, onion_c->friends_list[i].real_client_id, crypto_box_PUBLICKEYBYTES) == 0)
return i;
}
return -1;
}
/* Set the size of the friend list to num.
*
* return -1 if realloc fails.
* return 0 if it succeeds.
*/
static int realloc_onion_friends(Onion_Client *onion_c, uint32_t num)
{
if (num == 0) {
free(onion_c->friends_list);
onion_c->friends_list = NULL;
return 0;
}
Onion_Friend *newonion_friends = realloc(onion_c->friends_list, num * sizeof(Onion_Friend));
if (newonion_friends == NULL)
return -1;
onion_c->friends_list = newonion_friends;
return 0;
}
/* Add a friend who we want to connect to.
*
* return -1 on failure.
* return the friend number on success or if the friend was already added.
*/
int onion_addfriend(Onion_Client *onion_c, uint8_t *client_id)
{
int num = onion_friend_num(onion_c, client_id);
if (num != -1)
return num;
uint32_t i, index = ~0;
for (i = 0; i < onion_c->num_friends; ++i) {
if (onion_c->friends_list[i].status == 0) {
index = i;
break;
}
}
if (index == (uint32_t)~0) {
if (realloc_onion_friends(onion_c, onion_c->num_friends + 1) == -1)
return -1;
index = onion_c->num_friends;
memset(&(onion_c->friends_list[onion_c->num_friends]), 0, sizeof(Onion_Friend));
++onion_c->num_friends;
}
onion_c->friends_list[index].status = 1;
memcpy(onion_c->friends_list[index].real_client_id, client_id, crypto_box_PUBLICKEYBYTES);
crypto_box_keypair(onion_c->friends_list[index].temp_public_key, onion_c->friends_list[index].temp_secret_key);
return index;
}
/* Delete a friend.
*
* return -1 on failure.
* return the deleted friend number on success.
*/
int onion_delfriend(Onion_Client *onion_c, int friend_num)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (onion_c->friends_list[friend_num].is_fake_clientid)
DHT_delfriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id);
memset(&(onion_c->friends_list[friend_num]), 0, sizeof(Onion_Friend));
uint32_t i;
for (i = onion_c->num_friends; i != 0; --i) {
if (onion_c->friends_list[i].status != 0)
break;
}
if (onion_c->num_friends != i) {
onion_c->num_friends = i;
realloc_onion_friends(onion_c, onion_c->num_friends);
}
return friend_num;
}
/* Copy friends DHT public key into dht_key.
*
* return -1 on failure (no key copied).
* return 0 on success (key copied).
*/
int onion_getfriend_DHT_pubkey(Onion_Client *onion_c, int friend_num, uint8_t *dht_key)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (onion_c->friends_list[friend_num].status == 0)
return -1;
if (!onion_c->friends_list[friend_num].is_fake_clientid)
return -1;
memcpy(dht_key, onion_c->friends_list[friend_num].fake_client_id, crypto_box_PUBLICKEYBYTES);
return 0;
}
/* Get the ip of friend friendnum and put it in ip_port
*
* return -1, -- if client_id does NOT refer to a friend
* return 0, -- if client_id refers to a friend and we failed to find the friend (yet)
* return 1, ip if client_id refers to a friend and we found him
*
*/
int onion_getfriendip(Onion_Client *onion_c, int friend_num, IP_Port *ip_port)
{
uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES];
if (onion_getfriend_DHT_pubkey(onion_c, friend_num, dht_public_key) != 0)
return -1;
return DHT_getfriendip(onion_c->dht, dht_public_key, ip_port);
}
/* Set if friend is online or not.
* NOTE: This function is there and should be used so that we don't send useless packets to the friend if he is online.
*
* is_online 1 means friend is online.
* is_online 0 means friend is offline
*
* return -1 on failure.
* return 0 on success.
*/
int onion_set_friend_online(Onion_Client *onion_c, int friend_num, uint8_t is_online)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (is_online == 0 && onion_c->friends_list[friend_num].is_online == 1)
onion_c->friends_list[friend_num].last_seen = unix_time();
onion_c->friends_list[friend_num].is_online = is_online;
/* This should prevent some clock related issues */
if (!is_online)
onion_c->friends_list[friend_num].last_noreplay = 0;
return 0;
}
#define ANNOUNCE_FRIEND ONION_NODE_PING_INTERVAL
static void do_friend(Onion_Client *onion_c, uint16_t friendnum)
{
if (friendnum >= onion_c->num_friends)
return;
if (onion_c->friends_list[friendnum].status == 0)
return;
uint32_t i, count = 0;
Onion_Node *list_nodes = onion_c->friends_list[friendnum].clients_list;
if (!onion_c->friends_list[friendnum].is_online) {
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++count;
if (list_nodes[i].last_pinged == 0) {
list_nodes[i].last_pinged = unix_time();
continue;
}
if (is_timeout(list_nodes[i].last_pinged, ANNOUNCE_FRIEND)) {
if (client_send_announce_request(onion_c, friendnum + 1, list_nodes[i].ip_port, list_nodes[i].client_id, 0, ~0) == 0) {
list_nodes[i].last_pinged = unix_time();
}
}
}
if (count != MAX_ONION_CLIENTS) {
if (count < (uint32_t)rand() % MAX_ONION_CLIENTS) {
Node_format nodes_list[MAX_SENT_NODES];
uint32_t num_nodes = get_close_nodes(onion_c->dht, onion_c->friends_list[friendnum].real_client_id, nodes_list,
rand() % 2 ? AF_INET : AF_INET6, 1, 0);
for (i = 0; i < num_nodes; ++i)
client_send_announce_request(onion_c, friendnum + 1, nodes_list[i].ip_port, nodes_list[i].client_id, 0, ~0);
}
}
/* send packets to friend telling them our fake DHT id. */
if (is_timeout(onion_c->friends_list[friendnum].last_fakeid_onion_sent, ONION_FAKEID_INTERVAL))
if (send_fakeid_announce(onion_c, friendnum, 0) >= 1)
onion_c->friends_list[friendnum].last_fakeid_onion_sent = unix_time();
if (is_timeout(onion_c->friends_list[friendnum].last_fakeid_dht_sent, DHT_FAKEID_INTERVAL))
if (send_fakeid_announce(onion_c, friendnum, 1) >= 1)
onion_c->friends_list[friendnum].last_fakeid_dht_sent = unix_time();
}
}
/* Timeout before which a peer is considered dead and removed from the DHT search. */
#define DEAD_ONION_TIMEOUT (10 * 60)
static void cleanup_friend(Onion_Client *onion_c, uint16_t friendnum)
{
if (friendnum >= onion_c->num_friends)
return;
if (onion_c->friends_list[friendnum].status == 0)
return;
if (onion_c->friends_list[friendnum].is_fake_clientid && !onion_c->friends_list[friendnum].is_online
&& is_timeout(onion_c->friends_list[friendnum].last_seen, DEAD_ONION_TIMEOUT)) {
onion_c->friends_list[friendnum].is_fake_clientid = 0;
DHT_delfriend(onion_c->dht, onion_c->friends_list[friendnum].fake_client_id);
}
}
/* Function to call when onion data packet with contents beginning with byte is received. */
void oniondata_registerhandler(Onion_Client *onion_c, uint8_t byte, oniondata_handler_callback cb, void *object)
{
onion_c->Onion_Data_Handlers[byte].function = cb;
onion_c->Onion_Data_Handlers[byte].object = object;
}
#define ANNOUNCE_INTERVAL_NOT_ANNOUNCED 10
#define ANNOUNCE_INTERVAL_ANNOUNCED ONION_NODE_PING_INTERVAL
static void do_announce(Onion_Client *onion_c)
{
uint32_t i, count = 0;
Onion_Node *list_nodes = onion_c->clients_announce_list;
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++count;
/* Don't announce ourselves the first time this is run to new peers */
if (list_nodes[i].last_pinged == 0) {
list_nodes[i].last_pinged = 1;
continue;
}
uint32_t interval = ANNOUNCE_INTERVAL_NOT_ANNOUNCED;
if (list_nodes[i].is_stored) {
interval = ANNOUNCE_INTERVAL_ANNOUNCED;
}
if (is_timeout(list_nodes[i].last_pinged, interval)) {
if (client_send_announce_request(onion_c, 0, list_nodes[i].ip_port, list_nodes[i].client_id,
list_nodes[i].ping_id, list_nodes[i].path_used) == 0) {
list_nodes[i].last_pinged = unix_time();
}
}
}
if (count != MAX_ONION_CLIENTS) {
if (count < (uint32_t)rand() % MAX_ONION_CLIENTS) {
Node_format nodes_list[MAX_SENT_NODES];
uint32_t num_nodes = get_close_nodes(onion_c->dht, onion_c->c->self_public_key, nodes_list,
rand() % 2 ? AF_INET : AF_INET6, 1, 0);
for (i = 0; i < num_nodes; ++i) {
client_send_announce_request(onion_c, 0, nodes_list[i].ip_port, nodes_list[i].client_id, 0, ~0);
}
}
}
}
void do_onion_client(Onion_Client *onion_c)
{
uint32_t i;
if (onion_c->last_run == unix_time())
return;
do_announce(onion_c);
for (i = 0; i < onion_c->num_friends; ++i) {
do_friend(onion_c, i);
cleanup_friend(onion_c, i);
onion_c->friends_list[i].ping_nodes_sent_second = 0;
}
onion_c->ping_nodes_sent_second = 0;
onion_c->last_run = unix_time();
}
Onion_Client *new_onion_client(Net_Crypto *c)
{
if (c == NULL)
return NULL;
Onion_Client *onion_c = calloc(1, sizeof(Onion_Client));
if (onion_c == NULL)
return NULL;
if (ping_array_init(&onion_c->announce_ping_array, ANNOUNCE_ARRAY_SIZE, ANNOUNCE_TIMEOUT) != 0) {
free(onion_c);
return NULL;
}
onion_c->dht = c->dht;
onion_c->net = c->dht->net;
onion_c->c = c;
new_symmetric_key(onion_c->secret_symmetric_key);
crypto_box_keypair(onion_c->temp_public_key, onion_c->temp_secret_key);
networking_registerhandler(onion_c->net, NET_PACKET_ANNOUNCE_RESPONSE, &handle_announce_response, onion_c);
networking_registerhandler(onion_c->net, NET_PACKET_ONION_DATA_RESPONSE, &handle_data_response, onion_c);
oniondata_registerhandler(onion_c, FAKEID_DATA_ID, &handle_fakeid_announce, onion_c);
cryptopacket_registerhandler(onion_c->dht, FAKEID_DATA_ID, &handle_dht_fakeid, onion_c);
return onion_c;
}
void kill_onion_client(Onion_Client *onion_c)
{
if (onion_c == NULL)
return;
ping_array_free_all(&onion_c->announce_ping_array);
realloc_onion_friends(onion_c, 0);
networking_registerhandler(onion_c->net, NET_PACKET_ANNOUNCE_RESPONSE, NULL, NULL);
networking_registerhandler(onion_c->net, NET_PACKET_ONION_DATA_RESPONSE, NULL, NULL);
oniondata_registerhandler(onion_c, FAKEID_DATA_ID, NULL, NULL);
cryptopacket_registerhandler(onion_c->dht, FAKEID_DATA_ID, NULL, NULL);
memset(onion_c, 0, sizeof(Onion_Client));
free(onion_c);
}
|