2 * Copyright (C) 2008-2015 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * Hochschule fuer Technik Rapperswil
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>.
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
23 #include <bio/bio_reader.h>
24 #include <bio/bio_writer.h>
25 #include <sa/ikev2/keymat_v2.h>
26 #include <crypto/diffie_hellman.h>
27 #include <crypto/hashers/hash_algorithm_set.h>
28 #include <encoding/payloads/sa_payload.h>
29 #include <encoding/payloads/ke_payload.h>
30 #include <encoding/payloads/nonce_payload.h>
32 /** maximum retries to do with cookies/other dh groups */
35 typedef struct private_ike_init_t private_ike_init_t
;
38 * Private members of a ike_init_t task.
40 struct private_ike_init_t
{
43 * Public methods and task_t interface.
53 * Are we the initiator?
58 * IKE config to establish
63 * diffie hellman group to use
65 diffie_hellman_group_t dh_group
;
68 * diffie hellman key exchange
73 * Applying DH public value failed?
78 * Keymat derivation (from IKE_SA)
88 * nonce chosen by peer
98 * Negotiated proposal used for IKE_SA
100 proposal_t
*proposal
;
103 * Old IKE_SA which gets rekeyed
108 * cookie received from responder
113 * retries done so far after failure (cookie or bad dh group)
118 * Whether to use Signature Authentication as per RFC 7427
120 bool signature_authentication
;
123 * Whether to follow IKEv2 redirects as per RFC 5685
125 bool follow_redirects
;
129 * Allocate our own nonce value
131 static bool generate_nonce(private_ike_init_t
*this)
135 DBG1(DBG_IKE
, "no nonce generator found to create nonce");
138 if (!this->nonceg
->allocate_nonce(this->nonceg
, NONCE_SIZE
,
141 DBG1(DBG_IKE
, "nonce allocation failed");
148 * Notify the peer about the hash algorithms we support or expect,
151 static void send_supported_hash_algorithms(private_ike_init_t
*this,
154 hash_algorithm_set_t
*algos
;
155 enumerator_t
*enumerator
, *rounds
;
156 bio_writer_t
*writer
;
157 hash_algorithm_t hash
;
164 algos
= hash_algorithm_set_create();
165 peer
= this->ike_sa
->get_peer_cfg(this->ike_sa
);
168 rounds
= peer
->create_auth_cfg_enumerator(peer
, FALSE
);
169 while (rounds
->enumerate(rounds
, &auth
))
171 enumerator
= auth
->create_enumerator(auth
);
172 while (enumerator
->enumerate(enumerator
, &rule
, &config
))
174 if (rule
== AUTH_RULE_SIGNATURE_SCHEME
)
176 hash
= hasher_from_signature_scheme(config
);
177 if (hasher_algorithm_for_ikev2(hash
))
179 algos
->add(algos
, hash
);
183 enumerator
->destroy(enumerator
);
185 rounds
->destroy(rounds
);
188 if (!algos
->count(algos
))
190 enumerator
= lib
->crypto
->create_hasher_enumerator(lib
->crypto
);
191 while (enumerator
->enumerate(enumerator
, &hash
, &plugin_name
))
193 if (hasher_algorithm_for_ikev2(hash
))
195 algos
->add(algos
, hash
);
198 enumerator
->destroy(enumerator
);
201 if (algos
->count(algos
))
203 writer
= bio_writer_create(0);
204 enumerator
= algos
->create_enumerator(algos
);
205 while (enumerator
->enumerate(enumerator
, &hash
))
207 writer
->write_uint16(writer
, hash
);
209 enumerator
->destroy(enumerator
);
210 message
->add_notify(message
, FALSE
, SIGNATURE_HASH_ALGORITHMS
,
211 writer
->get_buf(writer
));
212 writer
->destroy(writer
);
214 algos
->destroy(algos
);
218 * Store algorithms supported by other peer
220 static void handle_supported_hash_algorithms(private_ike_init_t
*this,
221 notify_payload_t
*notify
)
223 bio_reader_t
*reader
;
227 reader
= bio_reader_create(notify
->get_notification_data(notify
));
228 while (reader
->remaining(reader
) >= 2 && reader
->read_uint16(reader
, &algo
))
230 if (hasher_algorithm_for_ikev2(algo
))
232 this->keymat
->add_hash_algorithm(this->keymat
, algo
);
236 reader
->destroy(reader
);
240 this->ike_sa
->enable_extension(this->ike_sa
, EXT_SIGNATURE_AUTH
);
245 * build the payloads for the message
247 static bool build_payloads(private_ike_init_t
*this, message_t
*message
)
249 sa_payload_t
*sa_payload
;
250 ke_payload_t
*ke_payload
;
251 nonce_payload_t
*nonce_payload
;
252 linked_list_t
*proposal_list
;
254 proposal_t
*proposal
;
255 enumerator_t
*enumerator
;
257 id
= this->ike_sa
->get_id(this->ike_sa
);
259 this->config
= this->ike_sa
->get_ike_cfg(this->ike_sa
);
263 proposal_list
= this->config
->get_proposals(this->config
);
266 /* include SPI of new IKE_SA when we are rekeying */
267 enumerator
= proposal_list
->create_enumerator(proposal_list
);
268 while (enumerator
->enumerate(enumerator
, (void**)&proposal
))
270 proposal
->set_spi(proposal
, id
->get_initiator_spi(id
));
272 enumerator
->destroy(enumerator
);
275 sa_payload
= sa_payload_create_from_proposals_v2(proposal_list
);
276 proposal_list
->destroy_offset(proposal_list
, offsetof(proposal_t
, destroy
));
282 /* include SPI of new IKE_SA when we are rekeying */
283 this->proposal
->set_spi(this->proposal
, id
->get_responder_spi(id
));
285 sa_payload
= sa_payload_create_from_proposal_v2(this->proposal
);
287 message
->add_payload(message
, (payload_t
*)sa_payload
);
289 nonce_payload
= nonce_payload_create(PLV2_NONCE
);
290 nonce_payload
->set_nonce(nonce_payload
, this->my_nonce
);
291 ke_payload
= ke_payload_create_from_diffie_hellman(PLV2_KEY_EXCHANGE
,
295 DBG1(DBG_IKE
, "creating KE payload failed");
300 { /* payload order differs if we are rekeying */
301 message
->add_payload(message
, (payload_t
*)nonce_payload
);
302 message
->add_payload(message
, (payload_t
*)ke_payload
);
306 message
->add_payload(message
, (payload_t
*)ke_payload
);
307 message
->add_payload(message
, (payload_t
*)nonce_payload
);
310 /* negotiate fragmentation if we are not rekeying */
312 this->config
->fragmentation(this->config
) != FRAGMENTATION_NO
)
314 if (this->initiator
||
315 this->ike_sa
->supports_extension(this->ike_sa
,
316 EXT_IKE_FRAGMENTATION
))
318 message
->add_notify(message
, FALSE
, FRAGMENTATION_SUPPORTED
,
322 /* submit supported hash algorithms for signature authentication */
323 if (!this->old_sa
&& this->signature_authentication
)
325 if (this->initiator
||
326 this->ike_sa
->supports_extension(this->ike_sa
,
329 send_supported_hash_algorithms(this, message
);
332 /* notify other peer if we support redirection */
333 if (!this->old_sa
&& this->initiator
&& this->follow_redirects
)
335 identification_t
*gateway
;
339 from
= this->ike_sa
->get_redirected_from(this->ike_sa
);
342 gateway
= identification_create_from_sockaddr(
343 from
->get_sockaddr(from
));
344 data
= redirect_data_create(gateway
, chunk_empty
);
345 message
->add_notify(message
, FALSE
, REDIRECTED_FROM
, data
);
347 gateway
->destroy(gateway
);
351 message
->add_notify(message
, FALSE
, REDIRECT_SUPPORTED
,
359 * Read payloads from message
361 static void process_payloads(private_ike_init_t
*this, message_t
*message
)
363 enumerator_t
*enumerator
;
365 ke_payload_t
*ke_payload
= NULL
;
367 enumerator
= message
->create_payload_enumerator(message
);
368 while (enumerator
->enumerate(enumerator
, &payload
))
370 switch (payload
->get_type(payload
))
372 case PLV2_SECURITY_ASSOCIATION
:
374 sa_payload_t
*sa_payload
= (sa_payload_t
*)payload
;
375 linked_list_t
*proposal_list
;
378 proposal_list
= sa_payload
->get_proposals(sa_payload
);
379 private = this->ike_sa
->supports_extension(this->ike_sa
,
381 this->proposal
= this->config
->select_proposal(this->config
,
382 proposal_list
, private);
385 charon
->bus
->alert(charon
->bus
, ALERT_PROPOSAL_MISMATCH_IKE
,
388 proposal_list
->destroy_offset(proposal_list
,
389 offsetof(proposal_t
, destroy
));
392 case PLV2_KEY_EXCHANGE
:
394 ke_payload
= (ke_payload_t
*)payload
;
396 this->dh_group
= ke_payload
->get_dh_group_number(ke_payload
);
401 nonce_payload_t
*nonce_payload
= (nonce_payload_t
*)payload
;
403 this->other_nonce
= nonce_payload
->get_nonce(nonce_payload
);
408 notify_payload_t
*notify
= (notify_payload_t
*)payload
;
410 switch (notify
->get_notify_type(notify
))
412 case FRAGMENTATION_SUPPORTED
:
413 this->ike_sa
->enable_extension(this->ike_sa
,
414 EXT_IKE_FRAGMENTATION
);
416 case SIGNATURE_HASH_ALGORITHMS
:
417 if (this->signature_authentication
)
419 handle_supported_hash_algorithms(this, notify
);
422 case REDIRECT_SUPPORTED
:
423 this->ike_sa
->enable_extension(this->ike_sa
,
424 EXT_IKE_REDIRECTION
);
427 /* other notifies are handled elsewhere */
436 enumerator
->destroy(enumerator
);
438 if (ke_payload
&& this->proposal
&&
439 this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
441 if (!this->initiator
)
443 this->dh
= this->keymat
->keymat
.create_dh(
444 &this->keymat
->keymat
, this->dh_group
);
448 this->dh_failed
= !this->dh
->set_other_public_value(this->dh
,
449 ke_payload
->get_key_exchange_data(ke_payload
));
454 METHOD(task_t
, build_i
, status_t
,
455 private_ike_init_t
*this, message_t
*message
)
457 this->config
= this->ike_sa
->get_ike_cfg(this->ike_sa
);
458 DBG0(DBG_IKE
, "initiating IKE_SA %s[%d] to %H",
459 this->ike_sa
->get_name(this->ike_sa
),
460 this->ike_sa
->get_unique_id(this->ike_sa
),
461 this->ike_sa
->get_other_host(this->ike_sa
));
462 this->ike_sa
->set_state(this->ike_sa
, IKE_CONNECTING
);
464 if (this->retry
>= MAX_RETRIES
)
466 DBG1(DBG_IKE
, "giving up after %d retries", MAX_RETRIES
);
470 /* if the DH group is set via use_dh_group(), we already have a DH object */
473 this->dh_group
= this->config
->get_dh_group(this->config
);
474 this->dh
= this->keymat
->keymat
.create_dh(&this->keymat
->keymat
,
478 DBG1(DBG_IKE
, "configured DH group %N not supported",
479 diffie_hellman_group_names
, this->dh_group
);
484 /* generate nonce only when we are trying the first time */
485 if (this->my_nonce
.ptr
== NULL
)
487 if (!generate_nonce(this))
493 if (this->cookie
.ptr
)
495 message
->add_notify(message
, FALSE
, COOKIE
, this->cookie
);
498 if (!build_payloads(this, message
))
505 chunk_t connect_id
= this->ike_sa
->get_connect_id(this->ike_sa
);
508 message
->add_notify(message
, FALSE
, ME_CONNECTID
, connect_id
);
516 METHOD(task_t
, process_r
, status_t
,
517 private_ike_init_t
*this, message_t
*message
)
519 this->config
= this->ike_sa
->get_ike_cfg(this->ike_sa
);
520 DBG0(DBG_IKE
, "%H is initiating an IKE_SA", message
->get_source(message
));
521 this->ike_sa
->set_state(this->ike_sa
, IKE_CONNECTING
);
523 if (!generate_nonce(this))
530 notify_payload_t
*notify
= message
->get_notify(message
, ME_CONNECTID
);
533 chunk_t connect_id
= notify
->get_notification_data(notify
);
534 DBG2(DBG_IKE
, "received ME_CONNECTID %#B", &connect_id
);
535 charon
->connect_manager
->stop_checks(charon
->connect_manager
,
541 process_payloads(this, message
);
547 * Derive the keymat for the IKE_SA
549 static bool derive_keys(private_ike_init_t
*this,
550 chunk_t nonce_i
, chunk_t nonce_r
)
552 keymat_v2_t
*old_keymat
;
553 pseudo_random_function_t prf_alg
= PRF_UNDEFINED
;
554 chunk_t skd
= chunk_empty
;
557 id
= this->ike_sa
->get_id(this->ike_sa
);
560 /* rekeying: Include old SKd, use old PRF, apply SPI */
561 old_keymat
= (keymat_v2_t
*)this->old_sa
->get_keymat(this->old_sa
);
562 prf_alg
= old_keymat
->get_skd(old_keymat
, &skd
);
565 id
->set_responder_spi(id
, this->proposal
->get_spi(this->proposal
));
569 id
->set_initiator_spi(id
, this->proposal
->get_spi(this->proposal
));
572 if (!this->keymat
->derive_ike_keys(this->keymat
, this->proposal
, this->dh
,
573 nonce_i
, nonce_r
, id
, prf_alg
, skd
))
577 charon
->bus
->ike_keys(charon
->bus
, this->ike_sa
, this->dh
, chunk_empty
,
578 nonce_i
, nonce_r
, this->old_sa
, NULL
);
582 METHOD(task_t
, build_r
, status_t
,
583 private_ike_init_t
*this, message_t
*message
)
585 identification_t
*gateway
;
587 /* check if we have everything we need */
588 if (this->proposal
== NULL
||
589 this->other_nonce
.len
== 0 || this->my_nonce
.len
== 0)
591 DBG1(DBG_IKE
, "received proposals inacceptable");
592 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
595 this->ike_sa
->set_proposal(this->ike_sa
, this->proposal
);
597 /* check if we'd have to redirect the client */
598 if (this->ike_sa
->supports_extension(this->ike_sa
, EXT_IKE_REDIRECTION
) &&
599 charon
->redirect
->redirect_on_init(charon
->redirect
, this->ike_sa
,
604 DBG1(DBG_IKE
, "redirecting peer to %Y", gateway
);
605 data
= redirect_data_create(gateway
, this->other_nonce
);
606 message
->add_notify(message
, TRUE
, REDIRECT
, data
);
607 gateway
->destroy(gateway
);
612 if (this->dh
== NULL
||
613 !this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
617 if (this->proposal
->get_algorithm(this->proposal
, DIFFIE_HELLMAN_GROUP
,
620 DBG1(DBG_IKE
, "DH group %N inacceptable, requesting %N",
621 diffie_hellman_group_names
, this->dh_group
,
622 diffie_hellman_group_names
, group
);
623 this->dh_group
= group
;
624 group
= htons(group
);
625 message
->add_notify(message
, FALSE
, INVALID_KE_PAYLOAD
,
626 chunk_from_thing(group
));
630 DBG1(DBG_IKE
, "no acceptable proposal found");
637 DBG1(DBG_IKE
, "applying DH public value failed");
638 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
642 if (!derive_keys(this, this->other_nonce
, this->my_nonce
))
644 DBG1(DBG_IKE
, "key derivation failed");
645 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
648 if (!build_payloads(this, message
))
650 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
657 * Raise alerts for received notify errors
659 static void raise_alerts(private_ike_init_t
*this, notify_type_t type
)
665 case NO_PROPOSAL_CHOSEN
:
666 list
= this->config
->get_proposals(this->config
);
667 charon
->bus
->alert(charon
->bus
, ALERT_PROPOSAL_MISMATCH_IKE
, list
);
668 list
->destroy_offset(list
, offsetof(proposal_t
, destroy
));
675 METHOD(task_t
, process_i
, status_t
,
676 private_ike_init_t
*this, message_t
*message
)
678 enumerator_t
*enumerator
;
681 /* check for erroneous notifies */
682 enumerator
= message
->create_payload_enumerator(message
);
683 while (enumerator
->enumerate(enumerator
, &payload
))
685 if (payload
->get_type(payload
) == PLV2_NOTIFY
)
687 notify_payload_t
*notify
= (notify_payload_t
*)payload
;
688 notify_type_t type
= notify
->get_notify_type(notify
);
692 case INVALID_KE_PAYLOAD
:
695 diffie_hellman_group_t bad_group
;
697 bad_group
= this->dh_group
;
698 data
= notify
->get_notification_data(notify
);
699 this->dh_group
= ntohs(*((u_int16_t
*)data
.ptr
));
700 DBG1(DBG_IKE
, "peer didn't accept DH group %N, "
701 "it requested %N", diffie_hellman_group_names
,
702 bad_group
, diffie_hellman_group_names
, this->dh_group
);
704 if (this->old_sa
== NULL
)
705 { /* reset the IKE_SA if we are not rekeying */
706 this->ike_sa
->reset(this->ike_sa
);
709 enumerator
->destroy(enumerator
);
713 case NAT_DETECTION_SOURCE_IP
:
714 case NAT_DETECTION_DESTINATION_IP
:
715 /* skip, handled in ike_natd_t */
717 case MULTIPLE_AUTH_SUPPORTED
:
718 /* handled in ike_auth_t */
722 chunk_free(&this->cookie
);
723 this->cookie
= chunk_clone(notify
->get_notification_data(notify
));
724 this->ike_sa
->reset(this->ike_sa
);
725 enumerator
->destroy(enumerator
);
726 DBG2(DBG_IKE
, "received %N notify", notify_type_names
, type
);
732 identification_t
*gateway
;
733 chunk_t data
, nonce
= chunk_empty
;
734 status_t status
= FAILED
;
736 data
= notify
->get_notification_data(notify
);
737 gateway
= redirect_data_parse(data
, &nonce
);
738 enumerator
->destroy(enumerator
);
739 if (!gateway
|| !chunk_equals(nonce
, this->my_nonce
))
741 DBG1(DBG_IKE
, "received invalid REDIRECT notify");
743 else if (this->ike_sa
->handle_redirect(this->ike_sa
,
756 DBG1(DBG_IKE
, "received %N notify error",
757 notify_type_names
, type
);
758 enumerator
->destroy(enumerator
);
759 raise_alerts(this, type
);
762 DBG2(DBG_IKE
, "received %N notify",
763 notify_type_names
, type
);
769 enumerator
->destroy(enumerator
);
771 process_payloads(this, message
);
773 /* check if we have everything */
774 if (this->proposal
== NULL
||
775 this->other_nonce
.len
== 0 || this->my_nonce
.len
== 0)
777 DBG1(DBG_IKE
, "peers proposal selection invalid");
780 this->ike_sa
->set_proposal(this->ike_sa
, this->proposal
);
782 if (this->dh
== NULL
||
783 !this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
785 DBG1(DBG_IKE
, "peer DH group selection invalid");
791 DBG1(DBG_IKE
, "applying DH public value failed");
795 if (!derive_keys(this, this->my_nonce
, this->other_nonce
))
797 DBG1(DBG_IKE
, "key derivation failed");
803 METHOD(task_t
, get_type
, task_type_t
,
804 private_ike_init_t
*this)
806 return TASK_IKE_INIT
;
809 METHOD(task_t
, migrate
, void,
810 private_ike_init_t
*this, ike_sa_t
*ike_sa
)
812 DESTROY_IF(this->proposal
);
813 chunk_free(&this->other_nonce
);
815 this->ike_sa
= ike_sa
;
816 this->keymat
= (keymat_v2_t
*)ike_sa
->get_keymat(ike_sa
);
817 this->proposal
= NULL
;
818 this->dh_failed
= FALSE
;
819 if (this->dh
&& this->dh
->get_dh_group(this->dh
) != this->dh_group
)
820 { /* reset DH value only if group changed (INVALID_KE_PAYLOAD) */
821 this->dh
->destroy(this->dh
);
822 this->dh
= this->keymat
->keymat
.create_dh(&this->keymat
->keymat
,
827 METHOD(task_t
, destroy
, void,
828 private_ike_init_t
*this)
830 DESTROY_IF(this->dh
);
831 DESTROY_IF(this->proposal
);
832 DESTROY_IF(this->nonceg
);
833 chunk_free(&this->my_nonce
);
834 chunk_free(&this->other_nonce
);
835 chunk_free(&this->cookie
);
839 METHOD(ike_init_t
, get_lower_nonce
, chunk_t
,
840 private_ike_init_t
*this)
842 if (memcmp(this->my_nonce
.ptr
, this->other_nonce
.ptr
,
843 min(this->my_nonce
.len
, this->other_nonce
.len
)) < 0)
845 return this->my_nonce
;
849 return this->other_nonce
;
854 * Described in header.
856 ike_init_t
*ike_init_create(ike_sa_t
*ike_sa
, bool initiator
, ike_sa_t
*old_sa
)
858 private_ike_init_t
*this;
863 .get_type
= _get_type
,
867 .get_lower_nonce
= _get_lower_nonce
,
870 .initiator
= initiator
,
871 .dh_group
= MODP_NONE
,
872 .keymat
= (keymat_v2_t
*)ike_sa
->get_keymat(ike_sa
),
874 .signature_authentication
= lib
->settings
->get_bool(lib
->settings
,
875 "%s.signature_authentication", TRUE
, lib
->ns
),
876 .follow_redirects
= lib
->settings
->get_bool(lib
->settings
,
877 "%s.follow_redirects", TRUE
, lib
->ns
),
879 this->nonceg
= this->keymat
->keymat
.create_nonce_gen(&this->keymat
->keymat
);
883 this->public.task
.build
= _build_i
;
884 this->public.task
.process
= _process_i
;
888 this->public.task
.build
= _build_r
;
889 this->public.task
.process
= _process_r
;
891 return &this->public;