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 REDIRECTED_FROM
:
424 identification_t
*gateway
;
427 data
= notify
->get_notification_data(notify
);
428 gateway
= redirect_data_parse(data
, NULL
);
431 DBG1(DBG_IKE
, "received invalid REDIRECTED_FROM "
435 DBG1(DBG_IKE
, "client got redirected from %Y", gateway
);
436 gateway
->destroy(gateway
);
439 case REDIRECT_SUPPORTED
:
440 this->ike_sa
->enable_extension(this->ike_sa
,
441 EXT_IKE_REDIRECTION
);
444 /* other notifies are handled elsewhere */
453 enumerator
->destroy(enumerator
);
455 if (ke_payload
&& this->proposal
&&
456 this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
458 if (!this->initiator
)
460 this->dh
= this->keymat
->keymat
.create_dh(
461 &this->keymat
->keymat
, this->dh_group
);
465 this->dh_failed
= !this->dh
->set_other_public_value(this->dh
,
466 ke_payload
->get_key_exchange_data(ke_payload
));
471 METHOD(task_t
, build_i
, status_t
,
472 private_ike_init_t
*this, message_t
*message
)
474 this->config
= this->ike_sa
->get_ike_cfg(this->ike_sa
);
475 DBG0(DBG_IKE
, "initiating IKE_SA %s[%d] to %H",
476 this->ike_sa
->get_name(this->ike_sa
),
477 this->ike_sa
->get_unique_id(this->ike_sa
),
478 this->ike_sa
->get_other_host(this->ike_sa
));
479 this->ike_sa
->set_state(this->ike_sa
, IKE_CONNECTING
);
481 if (this->retry
>= MAX_RETRIES
)
483 DBG1(DBG_IKE
, "giving up after %d retries", MAX_RETRIES
);
487 /* if the DH group is set via use_dh_group(), we already have a DH object */
490 this->dh_group
= this->config
->get_dh_group(this->config
);
491 this->dh
= this->keymat
->keymat
.create_dh(&this->keymat
->keymat
,
495 DBG1(DBG_IKE
, "configured DH group %N not supported",
496 diffie_hellman_group_names
, this->dh_group
);
501 /* generate nonce only when we are trying the first time */
502 if (this->my_nonce
.ptr
== NULL
)
504 if (!generate_nonce(this))
510 if (this->cookie
.ptr
)
512 message
->add_notify(message
, FALSE
, COOKIE
, this->cookie
);
515 if (!build_payloads(this, message
))
522 chunk_t connect_id
= this->ike_sa
->get_connect_id(this->ike_sa
);
525 message
->add_notify(message
, FALSE
, ME_CONNECTID
, connect_id
);
533 METHOD(task_t
, process_r
, status_t
,
534 private_ike_init_t
*this, message_t
*message
)
536 this->config
= this->ike_sa
->get_ike_cfg(this->ike_sa
);
537 DBG0(DBG_IKE
, "%H is initiating an IKE_SA", message
->get_source(message
));
538 this->ike_sa
->set_state(this->ike_sa
, IKE_CONNECTING
);
540 if (!generate_nonce(this))
547 notify_payload_t
*notify
= message
->get_notify(message
, ME_CONNECTID
);
550 chunk_t connect_id
= notify
->get_notification_data(notify
);
551 DBG2(DBG_IKE
, "received ME_CONNECTID %#B", &connect_id
);
552 charon
->connect_manager
->stop_checks(charon
->connect_manager
,
558 process_payloads(this, message
);
564 * Derive the keymat for the IKE_SA
566 static bool derive_keys(private_ike_init_t
*this,
567 chunk_t nonce_i
, chunk_t nonce_r
)
569 keymat_v2_t
*old_keymat
;
570 pseudo_random_function_t prf_alg
= PRF_UNDEFINED
;
571 chunk_t skd
= chunk_empty
;
574 id
= this->ike_sa
->get_id(this->ike_sa
);
577 /* rekeying: Include old SKd, use old PRF, apply SPI */
578 old_keymat
= (keymat_v2_t
*)this->old_sa
->get_keymat(this->old_sa
);
579 prf_alg
= old_keymat
->get_skd(old_keymat
, &skd
);
582 id
->set_responder_spi(id
, this->proposal
->get_spi(this->proposal
));
586 id
->set_initiator_spi(id
, this->proposal
->get_spi(this->proposal
));
589 if (!this->keymat
->derive_ike_keys(this->keymat
, this->proposal
, this->dh
,
590 nonce_i
, nonce_r
, id
, prf_alg
, skd
))
594 charon
->bus
->ike_keys(charon
->bus
, this->ike_sa
, this->dh
, chunk_empty
,
595 nonce_i
, nonce_r
, this->old_sa
, NULL
);
599 METHOD(task_t
, build_r
, status_t
,
600 private_ike_init_t
*this, message_t
*message
)
602 identification_t
*gateway
;
604 /* check if we have everything we need */
605 if (this->proposal
== NULL
||
606 this->other_nonce
.len
== 0 || this->my_nonce
.len
== 0)
608 DBG1(DBG_IKE
, "received proposals inacceptable");
609 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
612 this->ike_sa
->set_proposal(this->ike_sa
, this->proposal
);
614 /* check if we'd have to redirect the client */
615 if (this->ike_sa
->supports_extension(this->ike_sa
, EXT_IKE_REDIRECTION
) &&
616 charon
->redirect
->redirect_on_init(charon
->redirect
, this->ike_sa
,
621 DBG1(DBG_IKE
, "redirecting peer to %Y", gateway
);
622 data
= redirect_data_create(gateway
, this->other_nonce
);
623 message
->add_notify(message
, TRUE
, REDIRECT
, data
);
624 gateway
->destroy(gateway
);
629 if (this->dh
== NULL
||
630 !this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
634 if (this->proposal
->get_algorithm(this->proposal
, DIFFIE_HELLMAN_GROUP
,
637 DBG1(DBG_IKE
, "DH group %N inacceptable, requesting %N",
638 diffie_hellman_group_names
, this->dh_group
,
639 diffie_hellman_group_names
, group
);
640 this->dh_group
= group
;
641 group
= htons(group
);
642 message
->add_notify(message
, FALSE
, INVALID_KE_PAYLOAD
,
643 chunk_from_thing(group
));
647 DBG1(DBG_IKE
, "no acceptable proposal found");
654 DBG1(DBG_IKE
, "applying DH public value failed");
655 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
659 if (!derive_keys(this, this->other_nonce
, this->my_nonce
))
661 DBG1(DBG_IKE
, "key derivation failed");
662 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
665 if (!build_payloads(this, message
))
667 message
->add_notify(message
, TRUE
, NO_PROPOSAL_CHOSEN
, chunk_empty
);
674 * Raise alerts for received notify errors
676 static void raise_alerts(private_ike_init_t
*this, notify_type_t type
)
682 case NO_PROPOSAL_CHOSEN
:
683 list
= this->config
->get_proposals(this->config
);
684 charon
->bus
->alert(charon
->bus
, ALERT_PROPOSAL_MISMATCH_IKE
, list
);
685 list
->destroy_offset(list
, offsetof(proposal_t
, destroy
));
692 METHOD(task_t
, process_i
, status_t
,
693 private_ike_init_t
*this, message_t
*message
)
695 enumerator_t
*enumerator
;
698 /* check for erroneous notifies */
699 enumerator
= message
->create_payload_enumerator(message
);
700 while (enumerator
->enumerate(enumerator
, &payload
))
702 if (payload
->get_type(payload
) == PLV2_NOTIFY
)
704 notify_payload_t
*notify
= (notify_payload_t
*)payload
;
705 notify_type_t type
= notify
->get_notify_type(notify
);
709 case INVALID_KE_PAYLOAD
:
712 diffie_hellman_group_t bad_group
;
714 bad_group
= this->dh_group
;
715 data
= notify
->get_notification_data(notify
);
716 this->dh_group
= ntohs(*((u_int16_t
*)data
.ptr
));
717 DBG1(DBG_IKE
, "peer didn't accept DH group %N, "
718 "it requested %N", diffie_hellman_group_names
,
719 bad_group
, diffie_hellman_group_names
, this->dh_group
);
721 if (this->old_sa
== NULL
)
722 { /* reset the IKE_SA if we are not rekeying */
723 this->ike_sa
->reset(this->ike_sa
);
726 enumerator
->destroy(enumerator
);
730 case NAT_DETECTION_SOURCE_IP
:
731 case NAT_DETECTION_DESTINATION_IP
:
732 /* skip, handled in ike_natd_t */
734 case MULTIPLE_AUTH_SUPPORTED
:
735 /* handled in ike_auth_t */
739 chunk_free(&this->cookie
);
740 this->cookie
= chunk_clone(notify
->get_notification_data(notify
));
741 this->ike_sa
->reset(this->ike_sa
);
742 enumerator
->destroy(enumerator
);
743 DBG2(DBG_IKE
, "received %N notify", notify_type_names
, type
);
749 identification_t
*gateway
;
750 chunk_t data
, nonce
= chunk_empty
;
751 status_t status
= FAILED
;
753 data
= notify
->get_notification_data(notify
);
754 gateway
= redirect_data_parse(data
, &nonce
);
755 enumerator
->destroy(enumerator
);
756 if (!gateway
|| !chunk_equals(nonce
, this->my_nonce
))
758 DBG1(DBG_IKE
, "received invalid REDIRECT notify");
760 else if (this->ike_sa
->handle_redirect(this->ike_sa
,
773 DBG1(DBG_IKE
, "received %N notify error",
774 notify_type_names
, type
);
775 enumerator
->destroy(enumerator
);
776 raise_alerts(this, type
);
779 DBG2(DBG_IKE
, "received %N notify",
780 notify_type_names
, type
);
786 enumerator
->destroy(enumerator
);
788 process_payloads(this, message
);
790 /* check if we have everything */
791 if (this->proposal
== NULL
||
792 this->other_nonce
.len
== 0 || this->my_nonce
.len
== 0)
794 DBG1(DBG_IKE
, "peers proposal selection invalid");
797 this->ike_sa
->set_proposal(this->ike_sa
, this->proposal
);
799 if (this->dh
== NULL
||
800 !this->proposal
->has_dh_group(this->proposal
, this->dh_group
))
802 DBG1(DBG_IKE
, "peer DH group selection invalid");
808 DBG1(DBG_IKE
, "applying DH public value failed");
812 if (!derive_keys(this, this->my_nonce
, this->other_nonce
))
814 DBG1(DBG_IKE
, "key derivation failed");
820 METHOD(task_t
, get_type
, task_type_t
,
821 private_ike_init_t
*this)
823 return TASK_IKE_INIT
;
826 METHOD(task_t
, migrate
, void,
827 private_ike_init_t
*this, ike_sa_t
*ike_sa
)
829 DESTROY_IF(this->proposal
);
830 chunk_free(&this->other_nonce
);
832 this->ike_sa
= ike_sa
;
833 this->keymat
= (keymat_v2_t
*)ike_sa
->get_keymat(ike_sa
);
834 this->proposal
= NULL
;
835 this->dh_failed
= FALSE
;
836 if (this->dh
&& this->dh
->get_dh_group(this->dh
) != this->dh_group
)
837 { /* reset DH value only if group changed (INVALID_KE_PAYLOAD) */
838 this->dh
->destroy(this->dh
);
839 this->dh
= this->keymat
->keymat
.create_dh(&this->keymat
->keymat
,
844 METHOD(task_t
, destroy
, void,
845 private_ike_init_t
*this)
847 DESTROY_IF(this->dh
);
848 DESTROY_IF(this->proposal
);
849 DESTROY_IF(this->nonceg
);
850 chunk_free(&this->my_nonce
);
851 chunk_free(&this->other_nonce
);
852 chunk_free(&this->cookie
);
856 METHOD(ike_init_t
, get_lower_nonce
, chunk_t
,
857 private_ike_init_t
*this)
859 if (memcmp(this->my_nonce
.ptr
, this->other_nonce
.ptr
,
860 min(this->my_nonce
.len
, this->other_nonce
.len
)) < 0)
862 return this->my_nonce
;
866 return this->other_nonce
;
871 * Described in header.
873 ike_init_t
*ike_init_create(ike_sa_t
*ike_sa
, bool initiator
, ike_sa_t
*old_sa
)
875 private_ike_init_t
*this;
880 .get_type
= _get_type
,
884 .get_lower_nonce
= _get_lower_nonce
,
887 .initiator
= initiator
,
888 .dh_group
= MODP_NONE
,
889 .keymat
= (keymat_v2_t
*)ike_sa
->get_keymat(ike_sa
),
891 .signature_authentication
= lib
->settings
->get_bool(lib
->settings
,
892 "%s.signature_authentication", TRUE
, lib
->ns
),
893 .follow_redirects
= lib
->settings
->get_bool(lib
->settings
,
894 "%s.follow_redirects", TRUE
, lib
->ns
),
896 this->nonceg
= this->keymat
->keymat
.create_nonce_gen(&this->keymat
->keymat
);
900 this->public.task
.build
= _build_i
;
901 this->public.task
.process
= _process_i
;
905 this->public.task
.build
= _build_r
;
906 this->public.task
.process
= _process_r
;
908 return &this->public;