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
|
/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */
#include "or.h"
extern or_options_t options; /* command-line and config-file options */
#ifndef USE_TLS
static int or_handshake_op_send_keys(connection_t *conn);
static int or_handshake_op_finished_sending_keys(connection_t *conn);
static int or_handshake_client_process_auth(connection_t *conn);
static int or_handshake_client_send_auth(connection_t *conn);
static int or_handshake_server_process_auth(connection_t *conn);
static int or_handshake_server_process_nonce(connection_t *conn);
static void conn_or_init_crypto(connection_t *conn);
static void connection_or_set_open(connection_t *conn);
#endif
/*
*
* these two functions are the main ways 'in' to connection_or
*
*/
int connection_or_process_inbuf(connection_t *conn) {
assert(conn && conn->type == CONN_TYPE_OR);
if(conn->inbuf_reached_eof) {
log_fn(LOG_DEBUG,"conn reached eof. Closing.");
return -1;
}
#ifdef USE_TLS
assert(conn->state == OR_CONN_STATE_OPEN);
return connection_process_cell_from_inbuf(conn);
#else
// log(LOG_DEBUG,"connection_or_process_inbuf(): state %d.",conn->state);
switch(conn->state) {
case OR_CONN_STATE_CLIENT_AUTH_WAIT:
return or_handshake_client_process_auth(conn);
case OR_CONN_STATE_SERVER_AUTH_WAIT:
return or_handshake_server_process_auth(conn);
case OR_CONN_STATE_SERVER_NONCE_WAIT:
return or_handshake_server_process_nonce(conn);
case OR_CONN_STATE_OPEN:
return connection_process_cell_from_inbuf(conn);
default:
log_fn(LOG_DEBUG,"called in state where I'm writing. Ignoring buf for now.");
}
return 0;
#endif
}
int connection_or_finished_flushing(connection_t *conn) {
int e, len=sizeof(e);
assert(conn && conn->type == CONN_TYPE_OR);
switch(conn->state) {
#ifndef USE_TLS
case OR_CONN_STATE_OP_SENDING_KEYS:
return or_handshake_op_finished_sending_keys(conn);
case OR_CONN_STATE_CLIENT_CONNECTING:
#else
case OR_CONN_STATE_CONNECTING:
#endif
if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0) { /* not yet */
if(!ERRNO_CONN_EINPROGRESS(errno)){
/* yuck. kill it. */
log_fn(LOG_DEBUG,"in-progress connect failed. Removing.");
return -1;
} else {
return 0; /* no change, see if next time is better */
}
}
/* the connect has finished. */
log_fn(LOG_DEBUG,"OR connection to router %s:%u established.",
conn->address,conn->port);
#ifdef USE_TLS
if(connection_tls_start_handshake(conn) < 0)
return -1;
#else
if(options.OnionRouter)
return or_handshake_client_send_auth(conn);
else
return or_handshake_op_send_keys(conn);
case OR_CONN_STATE_CLIENT_SENDING_AUTH:
log_fn(LOG_DEBUG,"client finished sending auth.");
conn->state = OR_CONN_STATE_CLIENT_AUTH_WAIT;
connection_watch_events(conn, POLLIN);
return 0;
case OR_CONN_STATE_CLIENT_SENDING_NONCE:
log_fn(LOG_DEBUG,"client finished sending nonce.");
conn_or_init_crypto(conn);
connection_or_set_open(conn);
return connection_process_inbuf(conn); /* in case there's anything waiting on it */
case OR_CONN_STATE_SERVER_SENDING_AUTH:
log_fn(LOG_DEBUG,"server finished sending auth.");
conn->state = OR_CONN_STATE_SERVER_NONCE_WAIT;
connection_watch_events(conn, POLLIN);
return 0;
#endif
case OR_CONN_STATE_OPEN:
connection_stop_writing(conn);
return 0;
default:
log_fn(LOG_ERR,"BUG: called in unexpected state.");
return 0;
}
}
/*********************/
connection_t *connection_or_connect(routerinfo_t *router) {
connection_t *conn;
struct sockaddr_in router_addr;
int s;
assert(router);
if(router_is_me(router->addr, router->or_port)) {
/* this is me! don't connect to me. */
log(LOG_DEBUG,"connection_or_connect(): This is me. Skipping.");
return NULL;
}
/* this function should never be called if we're already connected to router, but */
/* check first to be sure */
conn = connection_exact_get_by_addr_port(router->addr,router->or_port);
if(conn)
return conn;
conn = connection_new(CONN_TYPE_OR);
if(!conn) {
return NULL;
}
/* set up conn so it's got all the data we need to remember */
conn->addr = router->addr;
conn->port = router->or_port;
conn->bandwidth = router->bandwidth;
conn->pkey = crypto_pk_dup_key(router->pkey);
conn->address = strdup(router->address);
s=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
if (s < 0) {
log(LOG_ERR,"Error creating network socket.");
connection_free(conn);
return NULL;
}
set_socket_nonblocking(s);
memset((void *)&router_addr,0,sizeof(router_addr));
router_addr.sin_family = AF_INET;
router_addr.sin_port = htons(router->or_port);
router_addr.sin_addr.s_addr = htonl(router->addr);
log(LOG_DEBUG,"connection_or_connect() : Trying to connect to %s:%u.",router->address,router->or_port);
if(connect(s,(struct sockaddr *)&router_addr,sizeof(router_addr)) < 0){
if(!ERRNO_CONN_EINPROGRESS(errno)) {
/* yuck. kill it. */
connection_free(conn);
return NULL;
} else {
/* it's in progress. set state appropriately and return. */
conn->s = s;
if(connection_add(conn) < 0) { /* no space, forget it */
connection_free(conn);
return NULL;
}
log(LOG_DEBUG,"connection_or_connect() : connect in progress.");
connection_watch_events(conn, POLLIN | POLLOUT | POLLERR);
/* writable indicates finish, readable indicates broken link,
error indicates broken link on windows */
#ifdef USE_TLS
conn->state = OR_CONN_STATE_CONNECTING;
#else
conn->state = OR_CONN_STATE_CLIENT_CONNECTING;
#endif
return conn;
}
}
/* it succeeded. we're connected. */
conn->s = s;
if(connection_add(conn) < 0) { /* no space, forget it */
connection_free(conn);
return NULL;
}
log(LOG_DEBUG,"connection_or_connect() : Connection to router %s:%u established.",
router->address, router->or_port);
#ifdef USE_TLS
if(connection_tls_start_handshake(conn) >= 0)
return conn;
#else
if((options.OnionRouter && or_handshake_client_send_auth(conn) >= 0) ||
(!options.OnionRouter && or_handshake_op_send_keys(conn) >= 0))
return conn; /* success! */
#endif
/* failure */
connection_remove(conn);
connection_free(conn);
return NULL;
}
/* ********************************** */
#ifndef USE_TLS
/* Helper functions to implement handshaking */
#define FLAGS_LEN 2
#define KEY_LEN 16
#define ADDR_LEN 4
#define PORT_LEN 2
#define PKEY_LEN 128
static int
or_handshake_op_send_keys(connection_t *conn) {
unsigned char message[FLAGS_LEN + KEY_LEN + KEY_LEN];
unsigned char cipher[PKEY_LEN];
int retval;
assert(conn && conn->type == CONN_TYPE_OR);
conn->bandwidth = DEFAULT_BANDWIDTH_OP; /* XXX USE_TLS */
/* generate random keys */
if(crypto_cipher_generate_key(conn->f_crypto) ||
crypto_cipher_generate_key(conn->b_crypto)) {
log(LOG_ERR,"Cannot generate a secure symmetric key.");
return -1;
}
log(LOG_DEBUG,"or_handshake_op_send_keys() : Generated symmetric keys.");
/* compose the message */
*(uint16_t *)(message) = htons(HANDSHAKE_AS_OP);
memcpy((void *)(message+FLAGS_LEN),
(void *)crypto_cipher_get_key(conn->f_crypto), 16);
memcpy((void *)(message+FLAGS_LEN+KEY_LEN),
(void *)crypto_cipher_get_key(conn->b_crypto), 16);
/* encrypt with RSA */
if(crypto_pk_public_encrypt(conn->pkey, message, sizeof(message), cipher, RSA_PKCS1_PADDING) < 0) {
log(LOG_ERR,"or_handshake_op_send_keys(): Public key encryption failed.");
return -1;
}
log(LOG_DEBUG,"or_handshake_op_send_keys() : Encrypted authentication message.");
/* send message */
if(connection_write_to_buf(cipher, PKEY_LEN, conn) < 0) {
log(LOG_DEBUG,"or_handshake_op_send_keys(): my outbuf is full. Oops.");
return -1;
}
retval = connection_flush_buf(conn);
if(retval < 0) {
log(LOG_DEBUG,"or_handshake_op_send_keys(): bad socket while flushing.");
return -1;
}
if(retval > 0) {
/* still stuff on the buffer. */
conn->state = OR_CONN_STATE_OP_SENDING_KEYS;
connection_watch_events(conn, POLLOUT | POLLIN);
return 0;
}
/* it finished sending */
log(LOG_DEBUG,"or_handshake_op_send_keys(): Finished sending authentication message.");
return or_handshake_op_finished_sending_keys(conn);
}
static int
or_handshake_op_finished_sending_keys(connection_t *conn) {
/* do crypto initialization, etc */
conn_or_init_crypto(conn);
connection_or_set_open(conn);
circuit_n_conn_open(conn); /* send the pending onion(s) */
return 0;
}
static int
or_handshake_client_send_auth(connection_t *conn) {
int retval;
char buf[FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+
PORT_LEN+KEY_LEN+KEY_LEN];
char cipher[PKEY_LEN];
struct sockaddr_in me; /* my router identity */
assert(conn);
if(learn_my_address(&me) < 0)
return -1;
/* generate random keys */
if(crypto_cipher_generate_key(conn->f_crypto) ||
crypto_cipher_generate_key(conn->b_crypto)) {
log(LOG_ERR,"Cannot generate a secure symmetric key.");
return -1;
}
log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated symmetric keys.");
/* generate first message */
*(uint16_t*)buf = htons(HANDSHAKE_AS_OR);
*(uint32_t*)(buf+FLAGS_LEN) = me.sin_addr.s_addr; /* local address, network order */
*(uint16_t*)(buf+FLAGS_LEN+ADDR_LEN) = me.sin_port; /* local port, network order */
*(uint32_t*)(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN) = htonl(conn->addr); /* remote address */
*(uint16_t*)(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN) = htons(conn->port); /* remote port */
memcpy(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+PORT_LEN,
crypto_cipher_get_key(conn->f_crypto),16); /* keys */
memcpy(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+PORT_LEN+KEY_LEN,
crypto_cipher_get_key(conn->b_crypto),16);
log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated first authentication message.");
/* encrypt message */
retval = crypto_pk_public_encrypt(conn->pkey, buf, sizeof(buf), cipher,RSA_PKCS1_PADDING);
if (retval == -1) /* error */
{
log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port);
log(LOG_DEBUG,"or_handshake_client_send_auth() : Reason : %s.",crypto_perror());
return -1;
}
log(LOG_DEBUG,"or_handshake_client_send_auth() : Encrypted authentication message.");
/* send message */
if(connection_write_to_buf(cipher, PKEY_LEN, conn) < 0) {
log(LOG_DEBUG,"or_handshake_client_send_auth(): my outbuf is full. Oops.");
return -1;
}
retval = connection_flush_buf(conn);
if(retval < 0) {
log(LOG_DEBUG,"or_handshake_client_send_auth(): bad socket while flushing.");
return -1;
}
if(retval > 0) {
/* still stuff on the buffer. */
conn->state = OR_CONN_STATE_CLIENT_SENDING_AUTH;
connection_watch_events(conn, POLLOUT | POLLIN);
return 0;
}
/* it finished sending */
log(LOG_DEBUG,"or_handshake_client_send_auth(): Finished sending authentication message.");
conn->state = OR_CONN_STATE_CLIENT_AUTH_WAIT;
connection_watch_events(conn, POLLIN);
return 0;
}
static int
or_handshake_client_process_auth(connection_t *conn) {
char buf[128]; /* only 52 of this is expected to be used */
char cipher[128];
int retval;
struct sockaddr_in me; /* my router identity */
assert(conn);
if(learn_my_address(&me) < 0)
return -1;
if(conn->inbuf_datalen < 128) /* entire response available? */
return 0; /* not yet */
connection_fetch_from_buf(cipher,128,conn);
log(LOG_DEBUG,"or_handshake_client_process_auth() : Received auth.");
/* decrypt response */
retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf, RSA_PKCS1_PADDING);
if (retval == -1)
{
log(LOG_ERR,"Public-key decryption failed during authentication to %s:%u.",
conn->address,conn->port);
log(LOG_DEBUG,"or_handshake_client_process_auth() : Reason : %s.",
crypto_perror());
return -1;
}
else if (retval != 52)
{
log(LOG_ERR,"client_process_auth: incorrect response from router %s:%u.",
conn->address,conn->port);
return -1;
}
log(LOG_DEBUG,"or_handshake_client_process_auth() : Decrypted response.");
/* check validity */
if ( (*(uint32_t*)buf != me.sin_addr.s_addr) || /* local address, network order */
(*(uint16_t*)(buf+4) != me.sin_port) || /* local port, network order */
(ntohl(*(uint32_t*)(buf+6)) != conn->addr) || /* remote address */
(ntohs(*(uint16_t*)(buf+10)) != conn->port) ) { /* remote port */
log(LOG_ERR,"client_process_auth: Router %s:%u: bad address info.", conn->address,conn->port);
return -1;
}
if ( (memcmp(crypto_cipher_get_key(conn->f_crypto), buf+12, 16)) ||/* keys */
(memcmp(crypto_cipher_get_key(conn->b_crypto), buf+28, 16)) ) {
log(LOG_ERR,"client_process_auth: Router %s:%u: bad key info.",conn->address,conn->port);
return -1;
}
log(LOG_DEBUG,"or_handshake_client_process_auth() : Response valid.");
/* reply is just local addr/port, remote addr/port, nonce */
memcpy(buf+12, buf+44, 8);
/* encrypt reply */
retval = crypto_pk_public_encrypt(conn->pkey, buf, 20, cipher,RSA_PKCS1_PADDING);
if (retval == -1) /* error */
{
log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port);
log(LOG_DEBUG,"or_handshake_client_process_auth() : Reason : %s.",crypto_perror());
return -1;
}
/* send the message */
if(connection_write_to_buf(cipher, 128, conn) < 0) {
log(LOG_DEBUG,"or_handshake_client_process_auth(): my outbuf is full. Oops.");
return -1;
}
retval = connection_flush_buf(conn);
if(retval < 0) {
log(LOG_DEBUG,"or_handshake_client_process_auth(): bad socket while flushing.");
return -1;
}
if(retval > 0) {
/* still stuff on the buffer. */
conn->state = OR_CONN_STATE_CLIENT_SENDING_NONCE;
connection_watch_events(conn, POLLOUT | POLLIN);
/* return(connection_process_inbuf(conn)); process the rest of the inbuf */
return 0;
}
/* it finished sending */
log(LOG_DEBUG,"or_handshake_client_process_auth(): Finished sending nonce.");
conn_or_init_crypto(conn);
connection_or_set_open(conn);
return connection_process_inbuf(conn); /* process the rest of the inbuf */
}
/*
*
* auth handshake, as performed by OR *receiving* the connection
*
*/
static int
or_handshake_server_process_auth(connection_t *conn) {
int retval;
char buf[128]; /* 50 of this is expected to be used for OR, 38 for OP */
char cipher[128];
unsigned char iv[16];
uint32_t addr;
uint16_t port;
routerinfo_t *router;
assert(conn);
log(LOG_DEBUG,"or_handshake_server_process_auth() entered.");
if(conn->inbuf_datalen < 128) /* entire response available? */
return 0; /* not yet */
connection_fetch_from_buf(cipher,128,conn);
log(LOG_DEBUG,"or_handshake_server_process_auth() : Received auth.");
/* decrypt response */
retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf, RSA_PKCS1_PADDING);
if (retval == -1) {
log(LOG_ERR,"or_handshake_server_process_auth: Public-key decryption failed.");
log(LOG_DEBUG,"or_handshake_server_process_auth() : Reason : %s.",
crypto_perror());
return -1;
}
if (retval == 46) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): Decrypted OR-style auth message.");
if(ntohs(*(uint16_t*)buf) != HANDSHAKE_AS_OR) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): ...but wasn't labelled OR. Dropping.");
return -1;
}
/* identify the router */
addr = ntohl(*(uint32_t*)(buf+2)); /* save the IP address */
port = ntohs(*(uint16_t*)(buf+6)); /* save the port */
router = router_get_by_addr_port(addr,port);
if (!router) {
log(LOG_DEBUG,"or_handshake_server_process_auth() : unknown router '%s:%d'. Will drop.", conn->address, port);
return -1;
}
log(LOG_DEBUG,"or_handshake_server_process_auth() : Router identified as %s:%u.",
router->address,router->or_port);
if(connection_exact_get_by_addr_port(addr,port)) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): That router is already connected. Dropping.");
return -1;
}
/* save keys */
crypto_cipher_set_key(conn->b_crypto,buf+14);
crypto_cipher_set_key(conn->f_crypto,buf+30);
conn->bandwidth = router->bandwidth; /* XXX USE_TLS and below */
/* copy all relevant info to conn */
conn->addr = router->addr, conn->port = router->or_port;
conn->pkey = crypto_pk_dup_key(router->pkey);
if(conn->address)
free(conn->address);
conn->address = strdup(router->address);
/* generate a nonce */
retval = crypto_rand(8, conn->nonce);
if (retval) { /* error */
log(LOG_ERR,"Cannot generate a nonce.");
return -1;
}
log(LOG_DEBUG,"or_handshake_server_process_auth(): Nonce generated.");
memmove(buf, buf+2, 44);
memcpy(buf+44,conn->nonce,8); /* append the nonce to the end of the message */
/* encrypt message */
retval = crypto_pk_public_encrypt(conn->pkey, buf, 52, cipher,RSA_PKCS1_PADDING);
if (retval == -1) { /* error */
log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port);
log(LOG_DEBUG,"or_handshake_server_process_auth() : Reason : %s.",crypto_perror());
return -1;
}
log(LOG_DEBUG,"or_handshake_server_process_auth() : Reply encrypted.");
/* send message */
if(connection_write_to_buf(cipher, 128, conn) < 0) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): my outbuf is full. Oops.");
return -1;
}
retval = connection_flush_buf(conn);
if(retval < 0) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): bad socket while flushing.");
return -1;
}
if(retval > 0) {
/* still stuff on the buffer. */
conn->state = OR_CONN_STATE_SERVER_SENDING_AUTH;
connection_watch_events(conn, POLLOUT | POLLIN);
return 0;
}
/* it finished sending */
log(LOG_DEBUG,"or_handshake_server_process_auth(): Finished sending auth.");
conn->state = OR_CONN_STATE_SERVER_NONCE_WAIT;
connection_watch_events(conn, POLLIN);
return 0;
}
if(retval == 34) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): Decrypted OP-style auth message.");
if(ntohs(*(uint16_t*)buf) != HANDSHAKE_AS_OP) {
log(LOG_DEBUG,"or_handshake_server_process_auth(): ...but wasn't labelled OP. Dropping.");
return -1;
}
crypto_cipher_set_key(conn->b_crypto, buf+2);
crypto_cipher_set_key(conn->f_crypto, buf+18);
memset(iv, 0, 16);
crypto_cipher_set_iv(conn->b_crypto, iv);
crypto_cipher_set_iv(conn->f_crypto, iv);
crypto_cipher_encrypt_init_cipher(conn->b_crypto);
crypto_cipher_decrypt_init_cipher(conn->f_crypto);
conn->state = OR_CONN_STATE_OPEN;
connection_watch_events(conn, POLLIN);
return connection_process_inbuf(conn); /* in case they sent some cells along with the keys */
}
log(LOG_ERR,"or_handshake_server_process_auth(): received an incorrect authentication request.");
return -1;
}
static int
or_handshake_server_process_nonce(connection_t *conn) {
char buf[128];
char cipher[128];
int retval;
struct sockaddr_in me; /* my router identity */
assert(conn);
if(learn_my_address(&me) < 0)
return -1;
if(conn->inbuf_datalen < 128) /* entire response available? */
return 0; /* not yet */
connection_fetch_from_buf(cipher,128,conn);
log(LOG_DEBUG,"or_handshake_server_process_nonce() : Received auth.");
/* decrypt response */
retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf,RSA_PKCS1_PADDING);
if (retval == -1)
{
log(LOG_ERR,"Public-key decryption failed during authentication to %s:%u.",
conn->address,conn->port);
log(LOG_DEBUG,"or_handshake_server_process_nonce() : Reason : %s.",
crypto_perror());
return -1;
}
else if (retval != 20)
{
log(LOG_ERR,"server_process_nonce: incorrect response from router %s:%u.",
conn->address,conn->port);
return -1;
}
log(LOG_DEBUG,"or_handshake_server_process_nonce() : Response decrypted.");
/* check validity */
if ((ntohl(*(uint32_t*)buf) != conn->addr) || /* remote address */
(ntohs(*(uint16_t*)(buf+4)) != conn->port) || /* remote port */
(*(uint32_t*)(buf+6) != me.sin_addr.s_addr) || /* local address, network order */
(*(uint16_t*)(buf+10) != me.sin_port) || /* local port, network order */
(memcmp(conn->nonce,buf+12,8))) /* nonce */
{
log(LOG_ERR,"server_process_nonce: Router %s:%u gave bad response.",conn->address,conn->port);
return -1;
}
log(LOG_DEBUG,"or_handshake_server_process_nonce() : Response valid. Authentication complete.");
conn_or_init_crypto(conn);
connection_or_set_open(conn);
return connection_process_inbuf(conn); /* process the rest of the inbuf */
}
/*********************/
static void
connection_or_set_open(connection_t *conn) {
conn->state = OR_CONN_STATE_OPEN;
directory_set_dirty();
connection_watch_events(conn, POLLIN);
}
static void
conn_or_init_crypto(connection_t *conn) {
//int x;
unsigned char iv[16];
assert(conn);
memset((void *)iv, 0, 16);
crypto_cipher_set_iv(conn->f_crypto, iv);
crypto_cipher_set_iv(conn->b_crypto, iv);
crypto_cipher_encrypt_init_cipher(conn->f_crypto);
crypto_cipher_decrypt_init_cipher(conn->b_crypto);
/* always encrypt with f, always decrypt with b */
}
#endif
/*
Local Variables:
mode:c
indent-tabs-mode:nil
c-basic-offset:2
End:
*/
|