Nonce: Let get_nonce, allocate_nonce return boolean
[strongswan.git] / src / libcharon / sa / ikev2 / tasks / ike_init.c
1 /*
2 * Copyright (C) 2008-2009 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 */
17
18 #include "ike_init.h"
19
20 #include <string.h>
21
22 #include <daemon.h>
23 #include <sa/ikev2/keymat_v2.h>
24 #include <crypto/diffie_hellman.h>
25 #include <encoding/payloads/sa_payload.h>
26 #include <encoding/payloads/ke_payload.h>
27 #include <encoding/payloads/nonce_payload.h>
28
29 /** maximum retries to do with cookies/other dh groups */
30 #define MAX_RETRIES 5
31
32 typedef struct private_ike_init_t private_ike_init_t;
33
34 /**
35 * Private members of a ike_init_t task.
36 */
37 struct private_ike_init_t {
38
39 /**
40 * Public methods and task_t interface.
41 */
42 ike_init_t public;
43
44 /**
45 * Assigned IKE_SA.
46 */
47 ike_sa_t *ike_sa;
48
49 /**
50 * Are we the initiator?
51 */
52 bool initiator;
53
54 /**
55 * IKE config to establish
56 */
57 ike_cfg_t *config;
58
59 /**
60 * diffie hellman group to use
61 */
62 diffie_hellman_group_t dh_group;
63
64 /**
65 * diffie hellman key exchange
66 */
67 diffie_hellman_t *dh;
68
69 /**
70 * Keymat derivation (from IKE_SA)
71 */
72 keymat_v2_t *keymat;
73
74 /**
75 * nonce chosen by us
76 */
77 chunk_t my_nonce;
78
79 /**
80 * nonce chosen by peer
81 */
82 chunk_t other_nonce;
83
84 /**
85 * Negotiated proposal used for IKE_SA
86 */
87 proposal_t *proposal;
88
89 /**
90 * Old IKE_SA which gets rekeyed
91 */
92 ike_sa_t *old_sa;
93
94 /**
95 * cookie received from responder
96 */
97 chunk_t cookie;
98
99 /**
100 * retries done so far after failure (cookie or bad dh group)
101 */
102 u_int retry;
103 };
104
105 /**
106 * build the payloads for the message
107 */
108 static void build_payloads(private_ike_init_t *this, message_t *message)
109 {
110 sa_payload_t *sa_payload;
111 ke_payload_t *ke_payload;
112 nonce_payload_t *nonce_payload;
113 linked_list_t *proposal_list;
114 ike_sa_id_t *id;
115 proposal_t *proposal;
116 enumerator_t *enumerator;
117
118 id = this->ike_sa->get_id(this->ike_sa);
119
120 this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
121
122 if (this->initiator)
123 {
124 proposal_list = this->config->get_proposals(this->config);
125 if (this->old_sa)
126 {
127 /* include SPI of new IKE_SA when we are rekeying */
128 enumerator = proposal_list->create_enumerator(proposal_list);
129 while (enumerator->enumerate(enumerator, (void**)&proposal))
130 {
131 proposal->set_spi(proposal, id->get_initiator_spi(id));
132 }
133 enumerator->destroy(enumerator);
134 }
135
136 sa_payload = sa_payload_create_from_proposals_v2(proposal_list);
137 proposal_list->destroy_offset(proposal_list, offsetof(proposal_t, destroy));
138 }
139 else
140 {
141 if (this->old_sa)
142 {
143 /* include SPI of new IKE_SA when we are rekeying */
144 this->proposal->set_spi(this->proposal, id->get_responder_spi(id));
145 }
146 sa_payload = sa_payload_create_from_proposal_v2(this->proposal);
147 }
148 message->add_payload(message, (payload_t*)sa_payload);
149
150 nonce_payload = nonce_payload_create(NONCE);
151 nonce_payload->set_nonce(nonce_payload, this->my_nonce);
152 ke_payload = ke_payload_create_from_diffie_hellman(KEY_EXCHANGE, this->dh);
153
154 if (this->old_sa)
155 { /* payload order differs if we are rekeying */
156 message->add_payload(message, (payload_t*)nonce_payload);
157 message->add_payload(message, (payload_t*)ke_payload);
158 }
159 else
160 {
161 message->add_payload(message, (payload_t*)ke_payload);
162 message->add_payload(message, (payload_t*)nonce_payload);
163 }
164 }
165
166 /**
167 * Read payloads from message
168 */
169 static void process_payloads(private_ike_init_t *this, message_t *message)
170 {
171 enumerator_t *enumerator;
172 payload_t *payload;
173
174 enumerator = message->create_payload_enumerator(message);
175 while (enumerator->enumerate(enumerator, &payload))
176 {
177 switch (payload->get_type(payload))
178 {
179 case SECURITY_ASSOCIATION:
180 {
181 sa_payload_t *sa_payload = (sa_payload_t*)payload;
182 linked_list_t *proposal_list;
183 bool private;
184
185 proposal_list = sa_payload->get_proposals(sa_payload);
186 private = this->ike_sa->supports_extension(this->ike_sa,
187 EXT_STRONGSWAN);
188 this->proposal = this->config->select_proposal(this->config,
189 proposal_list, private);
190 proposal_list->destroy_offset(proposal_list,
191 offsetof(proposal_t, destroy));
192 break;
193 }
194 case KEY_EXCHANGE:
195 {
196 ke_payload_t *ke_payload = (ke_payload_t*)payload;
197
198 this->dh_group = ke_payload->get_dh_group_number(ke_payload);
199 if (!this->initiator)
200 {
201 this->dh = this->keymat->keymat.create_dh(
202 &this->keymat->keymat, this->dh_group);
203 }
204 if (this->dh)
205 {
206 this->dh->set_other_public_value(this->dh,
207 ke_payload->get_key_exchange_data(ke_payload));
208 }
209 break;
210 }
211 case NONCE:
212 {
213 nonce_payload_t *nonce_payload = (nonce_payload_t*)payload;
214
215 this->other_nonce = nonce_payload->get_nonce(nonce_payload);
216 break;
217 }
218 default:
219 break;
220 }
221 }
222 enumerator->destroy(enumerator);
223 }
224
225 METHOD(task_t, build_i, status_t,
226 private_ike_init_t *this, message_t *message)
227 {
228 this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
229 DBG0(DBG_IKE, "initiating IKE_SA %s[%d] to %H",
230 this->ike_sa->get_name(this->ike_sa),
231 this->ike_sa->get_unique_id(this->ike_sa),
232 this->ike_sa->get_other_host(this->ike_sa));
233 this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
234
235 if (this->retry >= MAX_RETRIES)
236 {
237 DBG1(DBG_IKE, "giving up after %d retries", MAX_RETRIES);
238 return FAILED;
239 }
240
241 /* if the DH group is set via use_dh_group(), we already have a DH object */
242 if (!this->dh)
243 {
244 this->dh_group = this->config->get_dh_group(this->config);
245 this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
246 this->dh_group);
247 if (!this->dh)
248 {
249 DBG1(DBG_IKE, "configured DH group %N not supported",
250 diffie_hellman_group_names, this->dh_group);
251 return FAILED;
252 }
253 }
254
255 /* generate nonce only when we are trying the first time */
256 if (this->my_nonce.ptr == NULL)
257 {
258 nonce_gen_t *nonceg;
259
260 nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat);
261 if (!nonceg)
262 {
263 DBG1(DBG_IKE, "no nonce generator found to create nonce");
264 return FAILED;
265 }
266 if (!nonceg->allocate_nonce(nonceg, NONCE_SIZE, &this->my_nonce))
267 {
268 DBG1(DBG_IKE, "nonce allocation failed");
269 nonceg->destroy(nonceg);
270 return FAILED;
271 }
272 nonceg->destroy(nonceg);
273 }
274
275 if (this->cookie.ptr)
276 {
277 message->add_notify(message, FALSE, COOKIE, this->cookie);
278 }
279
280 build_payloads(this, message);
281
282 #ifdef ME
283 {
284 chunk_t connect_id = this->ike_sa->get_connect_id(this->ike_sa);
285 if (connect_id.ptr)
286 {
287 message->add_notify(message, FALSE, ME_CONNECTID, connect_id);
288 }
289 }
290 #endif /* ME */
291
292 return NEED_MORE;
293 }
294
295 METHOD(task_t, process_r, status_t,
296 private_ike_init_t *this, message_t *message)
297 {
298 nonce_gen_t *nonceg;
299
300 this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
301 DBG0(DBG_IKE, "%H is initiating an IKE_SA", message->get_source(message));
302 this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
303
304 nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat);
305 if (!nonceg)
306 {
307 DBG1(DBG_IKE, "no nonce generator found to create nonce");
308 return FAILED;
309 }
310 if (!nonceg->allocate_nonce(nonceg, NONCE_SIZE, &this->my_nonce))
311 {
312 DBG1(DBG_IKE, "nonce allocation failed");
313 nonceg->destroy(nonceg);
314 return FAILED;
315 }
316 nonceg->destroy(nonceg);
317
318 #ifdef ME
319 {
320 notify_payload_t *notify = message->get_notify(message, ME_CONNECTID);
321 if (notify)
322 {
323 chunk_t connect_id = notify->get_notification_data(notify);
324 DBG2(DBG_IKE, "received ME_CONNECTID %#B", &connect_id);
325 charon->connect_manager->stop_checks(charon->connect_manager,
326 connect_id);
327 }
328 }
329 #endif /* ME */
330
331 process_payloads(this, message);
332
333 return NEED_MORE;
334 }
335
336 /**
337 * Derive the keymat for the IKE_SA
338 */
339 static bool derive_keys(private_ike_init_t *this,
340 chunk_t nonce_i, chunk_t nonce_r)
341 {
342 keymat_v2_t *old_keymat;
343 pseudo_random_function_t prf_alg = PRF_UNDEFINED;
344 chunk_t skd = chunk_empty;
345 ike_sa_id_t *id;
346
347 id = this->ike_sa->get_id(this->ike_sa);
348 if (this->old_sa)
349 {
350 /* rekeying: Include old SKd, use old PRF, apply SPI */
351 old_keymat = (keymat_v2_t*)this->old_sa->get_keymat(this->old_sa);
352 prf_alg = old_keymat->get_skd(old_keymat, &skd);
353 if (this->initiator)
354 {
355 id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
356 }
357 else
358 {
359 id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
360 }
361 }
362 if (!this->keymat->derive_ike_keys(this->keymat, this->proposal, this->dh,
363 nonce_i, nonce_r, id, prf_alg, skd))
364 {
365 return FALSE;
366 }
367 charon->bus->ike_keys(charon->bus, this->ike_sa, this->dh, chunk_empty,
368 nonce_i, nonce_r, this->old_sa, NULL);
369 return TRUE;
370 }
371
372 METHOD(task_t, build_r, status_t,
373 private_ike_init_t *this, message_t *message)
374 {
375 /* check if we have everything we need */
376 if (this->proposal == NULL ||
377 this->other_nonce.len == 0 || this->my_nonce.len == 0)
378 {
379 DBG1(DBG_IKE, "received proposals inacceptable");
380 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
381 return FAILED;
382 }
383 this->ike_sa->set_proposal(this->ike_sa, this->proposal);
384
385 if (this->dh == NULL ||
386 !this->proposal->has_dh_group(this->proposal, this->dh_group))
387 {
388 u_int16_t group;
389
390 if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
391 &group, NULL))
392 {
393 DBG1(DBG_IKE, "DH group %N inacceptable, requesting %N",
394 diffie_hellman_group_names, this->dh_group,
395 diffie_hellman_group_names, group);
396 this->dh_group = group;
397 group = htons(group);
398 message->add_notify(message, FALSE, INVALID_KE_PAYLOAD,
399 chunk_from_thing(group));
400 }
401 else
402 {
403 DBG1(DBG_IKE, "no acceptable proposal found");
404 }
405 return FAILED;
406 }
407
408 if (!derive_keys(this, this->other_nonce, this->my_nonce))
409 {
410 DBG1(DBG_IKE, "key derivation failed");
411 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
412 return FAILED;
413 }
414 build_payloads(this, message);
415 return SUCCESS;
416 }
417
418 METHOD(task_t, process_i, status_t,
419 private_ike_init_t *this, message_t *message)
420 {
421 enumerator_t *enumerator;
422 payload_t *payload;
423
424 /* check for erronous notifies */
425 enumerator = message->create_payload_enumerator(message);
426 while (enumerator->enumerate(enumerator, &payload))
427 {
428 if (payload->get_type(payload) == NOTIFY)
429 {
430 notify_payload_t *notify = (notify_payload_t*)payload;
431 notify_type_t type = notify->get_notify_type(notify);
432
433 switch (type)
434 {
435 case INVALID_KE_PAYLOAD:
436 {
437 chunk_t data;
438 diffie_hellman_group_t bad_group;
439
440 bad_group = this->dh_group;
441 data = notify->get_notification_data(notify);
442 this->dh_group = ntohs(*((u_int16_t*)data.ptr));
443 DBG1(DBG_IKE, "peer didn't accept DH group %N, "
444 "it requested %N", diffie_hellman_group_names,
445 bad_group, diffie_hellman_group_names, this->dh_group);
446
447 if (this->old_sa == NULL)
448 { /* reset the IKE_SA if we are not rekeying */
449 this->ike_sa->reset(this->ike_sa);
450 }
451
452 enumerator->destroy(enumerator);
453 this->retry++;
454 return NEED_MORE;
455 }
456 case NAT_DETECTION_SOURCE_IP:
457 case NAT_DETECTION_DESTINATION_IP:
458 /* skip, handled in ike_natd_t */
459 break;
460 case MULTIPLE_AUTH_SUPPORTED:
461 /* handled in ike_auth_t */
462 break;
463 case COOKIE:
464 {
465 chunk_free(&this->cookie);
466 this->cookie = chunk_clone(notify->get_notification_data(notify));
467 this->ike_sa->reset(this->ike_sa);
468 enumerator->destroy(enumerator);
469 DBG2(DBG_IKE, "received %N notify", notify_type_names, type);
470 this->retry++;
471 return NEED_MORE;
472 }
473 default:
474 {
475 if (type <= 16383)
476 {
477 DBG1(DBG_IKE, "received %N notify error",
478 notify_type_names, type);
479 enumerator->destroy(enumerator);
480 return FAILED;
481 }
482 DBG2(DBG_IKE, "received %N notify",
483 notify_type_names, type);
484 break;
485 }
486 }
487 }
488 }
489 enumerator->destroy(enumerator);
490
491 process_payloads(this, message);
492
493 /* check if we have everything */
494 if (this->proposal == NULL ||
495 this->other_nonce.len == 0 || this->my_nonce.len == 0)
496 {
497 DBG1(DBG_IKE, "peers proposal selection invalid");
498 return FAILED;
499 }
500 this->ike_sa->set_proposal(this->ike_sa, this->proposal);
501
502 if (this->dh == NULL ||
503 !this->proposal->has_dh_group(this->proposal, this->dh_group))
504 {
505 DBG1(DBG_IKE, "peer DH group selection invalid");
506 return FAILED;
507 }
508
509 if (!derive_keys(this, this->my_nonce, this->other_nonce))
510 {
511 DBG1(DBG_IKE, "key derivation failed");
512 return FAILED;
513 }
514 return SUCCESS;
515 }
516
517 METHOD(task_t, get_type, task_type_t,
518 private_ike_init_t *this)
519 {
520 return TASK_IKE_INIT;
521 }
522
523 METHOD(task_t, migrate, void,
524 private_ike_init_t *this, ike_sa_t *ike_sa)
525 {
526 DESTROY_IF(this->proposal);
527 chunk_free(&this->other_nonce);
528
529 this->ike_sa = ike_sa;
530 this->keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa);
531 this->proposal = NULL;
532 if (this->dh && this->dh->get_dh_group(this->dh) != this->dh_group)
533 { /* reset DH value only if group changed (INVALID_KE_PAYLOAD) */
534 this->dh->destroy(this->dh);
535 this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
536 this->dh_group);
537 }
538 }
539
540 METHOD(task_t, destroy, void,
541 private_ike_init_t *this)
542 {
543 DESTROY_IF(this->dh);
544 DESTROY_IF(this->proposal);
545 chunk_free(&this->my_nonce);
546 chunk_free(&this->other_nonce);
547 chunk_free(&this->cookie);
548 free(this);
549 }
550
551 METHOD(ike_init_t, get_lower_nonce, chunk_t,
552 private_ike_init_t *this)
553 {
554 if (memcmp(this->my_nonce.ptr, this->other_nonce.ptr,
555 min(this->my_nonce.len, this->other_nonce.len)) < 0)
556 {
557 return this->my_nonce;
558 }
559 else
560 {
561 return this->other_nonce;
562 }
563 }
564
565 /*
566 * Described in header.
567 */
568 ike_init_t *ike_init_create(ike_sa_t *ike_sa, bool initiator, ike_sa_t *old_sa)
569 {
570 private_ike_init_t *this;
571
572 INIT(this,
573 .public = {
574 .task = {
575 .get_type = _get_type,
576 .migrate = _migrate,
577 .destroy = _destroy,
578 },
579 .get_lower_nonce = _get_lower_nonce,
580 },
581 .ike_sa = ike_sa,
582 .initiator = initiator,
583 .dh_group = MODP_NONE,
584 .keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa),
585 .old_sa = old_sa,
586 );
587
588 if (initiator)
589 {
590 this->public.task.build = _build_i;
591 this->public.task.process = _process_i;
592 }
593 else
594 {
595 this->public.task.build = _build_r;
596 this->public.task.process = _process_r;
597 }
598
599 return &this->public;
600 }