868680bb653dfb6509ae5b2a0bc536dabdd76aa8
[strongswan.git] / src / libcharon / sa / 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/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_proposal_list(SECURITY_ASSOCIATION,
137 proposal_list);
138 proposal_list->destroy_offset(proposal_list, offsetof(proposal_t, destroy));
139 }
140 else
141 {
142 if (this->old_sa)
143 {
144 /* include SPI of new IKE_SA when we are rekeying */
145 this->proposal->set_spi(this->proposal, id->get_responder_spi(id));
146 }
147 sa_payload = sa_payload_create_from_proposal(SECURITY_ASSOCIATION,
148 this->proposal);
149 }
150 message->add_payload(message, (payload_t*)sa_payload);
151
152 nonce_payload = nonce_payload_create(NONCE);
153 nonce_payload->set_nonce(nonce_payload, this->my_nonce);
154 ke_payload = ke_payload_create_from_diffie_hellman(KEY_EXCHANGE, this->dh);
155
156 if (this->old_sa)
157 { /* payload order differs if we are rekeying */
158 message->add_payload(message, (payload_t*)nonce_payload);
159 message->add_payload(message, (payload_t*)ke_payload);
160 }
161 else
162 {
163 message->add_payload(message, (payload_t*)ke_payload);
164 message->add_payload(message, (payload_t*)nonce_payload);
165 }
166 }
167
168 /**
169 * Read payloads from message
170 */
171 static void process_payloads(private_ike_init_t *this, message_t *message)
172 {
173 enumerator_t *enumerator;
174 payload_t *payload;
175
176 enumerator = message->create_payload_enumerator(message);
177 while (enumerator->enumerate(enumerator, &payload))
178 {
179 switch (payload->get_type(payload))
180 {
181 case SECURITY_ASSOCIATION:
182 {
183 sa_payload_t *sa_payload = (sa_payload_t*)payload;
184 linked_list_t *proposal_list;
185 bool private;
186
187 proposal_list = sa_payload->get_proposals(sa_payload);
188 private = this->ike_sa->supports_extension(this->ike_sa,
189 EXT_STRONGSWAN);
190 this->proposal = this->config->select_proposal(this->config,
191 proposal_list, private);
192 proposal_list->destroy_offset(proposal_list,
193 offsetof(proposal_t, destroy));
194 break;
195 }
196 case KEY_EXCHANGE:
197 {
198 ke_payload_t *ke_payload = (ke_payload_t*)payload;
199
200 this->dh_group = ke_payload->get_dh_group_number(ke_payload);
201 if (!this->initiator)
202 {
203 this->dh = this->keymat->keymat.create_dh(
204 &this->keymat->keymat, this->dh_group);
205 }
206 if (this->dh)
207 {
208 this->dh->set_other_public_value(this->dh,
209 ke_payload->get_key_exchange_data(ke_payload));
210 }
211 break;
212 }
213 case NONCE:
214 {
215 nonce_payload_t *nonce_payload = (nonce_payload_t*)payload;
216
217 this->other_nonce = nonce_payload->get_nonce(nonce_payload);
218 break;
219 }
220 default:
221 break;
222 }
223 }
224 enumerator->destroy(enumerator);
225 }
226
227 METHOD(task_t, build_i, status_t,
228 private_ike_init_t *this, message_t *message)
229 {
230 rng_t *rng;
231
232 this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
233 DBG0(DBG_IKE, "initiating IKE_SA %s[%d] to %H",
234 this->ike_sa->get_name(this->ike_sa),
235 this->ike_sa->get_unique_id(this->ike_sa),
236 this->ike_sa->get_other_host(this->ike_sa));
237 this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
238
239 if (this->retry >= MAX_RETRIES)
240 {
241 DBG1(DBG_IKE, "giving up after %d retries", MAX_RETRIES);
242 return FAILED;
243 }
244
245 /* if the DH group is set via use_dh_group(), we already have a DH object */
246 if (!this->dh)
247 {
248 this->dh_group = this->config->get_dh_group(this->config);
249 this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
250 this->dh_group);
251 if (!this->dh)
252 {
253 DBG1(DBG_IKE, "configured DH group %N not supported",
254 diffie_hellman_group_names, this->dh_group);
255 return FAILED;
256 }
257 }
258
259 /* generate nonce only when we are trying the first time */
260 if (this->my_nonce.ptr == NULL)
261 {
262 rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
263 if (!rng)
264 {
265 DBG1(DBG_IKE, "error generating nonce");
266 return FAILED;
267 }
268 rng->allocate_bytes(rng, NONCE_SIZE, &this->my_nonce);
269 rng->destroy(rng);
270 }
271
272 if (this->cookie.ptr)
273 {
274 message->add_notify(message, FALSE, COOKIE, this->cookie);
275 }
276
277 build_payloads(this, message);
278
279 #ifdef ME
280 {
281 chunk_t connect_id = this->ike_sa->get_connect_id(this->ike_sa);
282 if (connect_id.ptr)
283 {
284 message->add_notify(message, FALSE, ME_CONNECTID, connect_id);
285 }
286 }
287 #endif /* ME */
288
289 return NEED_MORE;
290 }
291
292 METHOD(task_t, process_r, status_t,
293 private_ike_init_t *this, message_t *message)
294 {
295 rng_t *rng;
296
297 this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
298 DBG0(DBG_IKE, "%H is initiating an IKE_SA", message->get_source(message));
299 this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
300
301 rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
302 if (!rng)
303 {
304 DBG1(DBG_IKE, "error generating nonce");
305 return FAILED;
306 }
307 rng->allocate_bytes(rng, NONCE_SIZE, &this->my_nonce);
308 rng->destroy(rng);
309
310 #ifdef ME
311 {
312 notify_payload_t *notify = message->get_notify(message, ME_CONNECTID);
313 if (notify)
314 {
315 chunk_t connect_id = notify->get_notification_data(notify);
316 DBG2(DBG_IKE, "received ME_CONNECTID %#B", &connect_id);
317 charon->connect_manager->stop_checks(charon->connect_manager,
318 connect_id);
319 }
320 }
321 #endif /* ME */
322
323 process_payloads(this, message);
324
325 return NEED_MORE;
326 }
327
328 /**
329 * Derive the keymat for the IKE_SA
330 */
331 static bool derive_keys(private_ike_init_t *this,
332 chunk_t nonce_i, chunk_t nonce_r)
333 {
334 keymat_v2_t *old_keymat;
335 pseudo_random_function_t prf_alg = PRF_UNDEFINED;
336 chunk_t skd = chunk_empty;
337 ike_sa_id_t *id;
338
339 id = this->ike_sa->get_id(this->ike_sa);
340 if (this->old_sa)
341 {
342 /* rekeying: Include old SKd, use old PRF, apply SPI */
343 old_keymat = (keymat_v2_t*)this->old_sa->get_keymat(this->old_sa);
344 prf_alg = old_keymat->get_skd(old_keymat, &skd);
345 if (this->initiator)
346 {
347 id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
348 }
349 else
350 {
351 id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
352 }
353 }
354 if (!this->keymat->derive_ike_keys(this->keymat, this->proposal, this->dh,
355 nonce_i, nonce_r, id, prf_alg, skd))
356 {
357 return FALSE;
358 }
359 charon->bus->ike_keys(charon->bus, this->ike_sa, this->dh,
360 nonce_i, nonce_r, this->old_sa);
361 return TRUE;
362 }
363
364 METHOD(task_t, build_r, status_t,
365 private_ike_init_t *this, message_t *message)
366 {
367 /* check if we have everything we need */
368 if (this->proposal == NULL ||
369 this->other_nonce.len == 0 || this->my_nonce.len == 0)
370 {
371 DBG1(DBG_IKE, "received proposals inacceptable");
372 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
373 return FAILED;
374 }
375 this->ike_sa->set_proposal(this->ike_sa, this->proposal);
376
377 if (this->dh == NULL ||
378 !this->proposal->has_dh_group(this->proposal, this->dh_group))
379 {
380 u_int16_t group;
381
382 if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
383 &group, NULL))
384 {
385 DBG1(DBG_IKE, "DH group %N inacceptable, requesting %N",
386 diffie_hellman_group_names, this->dh_group,
387 diffie_hellman_group_names, group);
388 this->dh_group = group;
389 group = htons(group);
390 message->add_notify(message, FALSE, INVALID_KE_PAYLOAD,
391 chunk_from_thing(group));
392 }
393 else
394 {
395 DBG1(DBG_IKE, "no acceptable proposal found");
396 }
397 return FAILED;
398 }
399
400 if (!derive_keys(this, this->other_nonce, this->my_nonce))
401 {
402 DBG1(DBG_IKE, "key derivation failed");
403 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
404 return FAILED;
405 }
406 build_payloads(this, message);
407 return SUCCESS;
408 }
409
410 METHOD(task_t, process_i, status_t,
411 private_ike_init_t *this, message_t *message)
412 {
413 enumerator_t *enumerator;
414 payload_t *payload;
415
416 /* check for erronous notifies */
417 enumerator = message->create_payload_enumerator(message);
418 while (enumerator->enumerate(enumerator, &payload))
419 {
420 if (payload->get_type(payload) == NOTIFY)
421 {
422 notify_payload_t *notify = (notify_payload_t*)payload;
423 notify_type_t type = notify->get_notify_type(notify);
424
425 switch (type)
426 {
427 case INVALID_KE_PAYLOAD:
428 {
429 chunk_t data;
430 diffie_hellman_group_t bad_group;
431
432 bad_group = this->dh_group;
433 data = notify->get_notification_data(notify);
434 this->dh_group = ntohs(*((u_int16_t*)data.ptr));
435 DBG1(DBG_IKE, "peer didn't accept DH group %N, "
436 "it requested %N", diffie_hellman_group_names,
437 bad_group, diffie_hellman_group_names, this->dh_group);
438
439 if (this->old_sa == NULL)
440 { /* reset the IKE_SA if we are not rekeying */
441 this->ike_sa->reset(this->ike_sa);
442 }
443
444 enumerator->destroy(enumerator);
445 this->retry++;
446 return NEED_MORE;
447 }
448 case NAT_DETECTION_SOURCE_IP:
449 case NAT_DETECTION_DESTINATION_IP:
450 /* skip, handled in ike_natd_t */
451 break;
452 case MULTIPLE_AUTH_SUPPORTED:
453 /* handled in ike_auth_t */
454 break;
455 case COOKIE:
456 {
457 chunk_free(&this->cookie);
458 this->cookie = chunk_clone(notify->get_notification_data(notify));
459 this->ike_sa->reset(this->ike_sa);
460 enumerator->destroy(enumerator);
461 DBG2(DBG_IKE, "received %N notify", notify_type_names, type);
462 this->retry++;
463 return NEED_MORE;
464 }
465 default:
466 {
467 if (type <= 16383)
468 {
469 DBG1(DBG_IKE, "received %N notify error",
470 notify_type_names, type);
471 enumerator->destroy(enumerator);
472 return FAILED;
473 }
474 DBG2(DBG_IKE, "received %N notify",
475 notify_type_names, type);
476 break;
477 }
478 }
479 }
480 }
481 enumerator->destroy(enumerator);
482
483 process_payloads(this, message);
484
485 /* check if we have everything */
486 if (this->proposal == NULL ||
487 this->other_nonce.len == 0 || this->my_nonce.len == 0)
488 {
489 DBG1(DBG_IKE, "peers proposal selection invalid");
490 return FAILED;
491 }
492 this->ike_sa->set_proposal(this->ike_sa, this->proposal);
493
494 if (this->dh == NULL ||
495 !this->proposal->has_dh_group(this->proposal, this->dh_group))
496 {
497 DBG1(DBG_IKE, "peer DH group selection invalid");
498 return FAILED;
499 }
500
501 if (!derive_keys(this, this->my_nonce, this->other_nonce))
502 {
503 DBG1(DBG_IKE, "key derivation failed");
504 return FAILED;
505 }
506 return SUCCESS;
507 }
508
509 METHOD(task_t, get_type, task_type_t,
510 private_ike_init_t *this)
511 {
512 return TASK_IKE_INIT;
513 }
514
515 METHOD(task_t, migrate, void,
516 private_ike_init_t *this, ike_sa_t *ike_sa)
517 {
518 DESTROY_IF(this->proposal);
519 chunk_free(&this->other_nonce);
520
521 this->ike_sa = ike_sa;
522 this->keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa);
523 this->proposal = NULL;
524 DESTROY_IF(this->dh);
525 this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
526 this->dh_group);
527 }
528
529 METHOD(task_t, destroy, void,
530 private_ike_init_t *this)
531 {
532 DESTROY_IF(this->dh);
533 DESTROY_IF(this->proposal);
534 chunk_free(&this->my_nonce);
535 chunk_free(&this->other_nonce);
536 chunk_free(&this->cookie);
537 free(this);
538 }
539
540 METHOD(ike_init_t, get_lower_nonce, chunk_t,
541 private_ike_init_t *this)
542 {
543 if (memcmp(this->my_nonce.ptr, this->other_nonce.ptr,
544 min(this->my_nonce.len, this->other_nonce.len)) < 0)
545 {
546 return this->my_nonce;
547 }
548 else
549 {
550 return this->other_nonce;
551 }
552 }
553
554 /*
555 * Described in header.
556 */
557 ike_init_t *ike_init_create(ike_sa_t *ike_sa, bool initiator, ike_sa_t *old_sa)
558 {
559 private_ike_init_t *this;
560
561 INIT(this,
562 .public = {
563 .task = {
564 .get_type = _get_type,
565 .migrate = _migrate,
566 .destroy = _destroy,
567 },
568 .get_lower_nonce = _get_lower_nonce,
569 },
570 .ike_sa = ike_sa,
571 .initiator = initiator,
572 .dh_group = MODP_NONE,
573 .keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa),
574 .old_sa = old_sa,
575 );
576
577 if (initiator)
578 {
579 this->public.task.build = _build_i;
580 this->public.task.process = _process_i;
581 }
582 else
583 {
584 this->public.task.build = _build_r;
585 this->public.task.process = _process_r;
586 }
587
588 return &this->public;
589 }