src/libcharon/sa/ikev2/tasks/ike_init.c

   1 /*
   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
   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 <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>
  31
  32 /** maximum retries to do with cookies/other dh groups */
  33 #define MAX_RETRIES 5
  34
  35 typedef struct private_ike_init_t private_ike_init_t;
  36
  37 /**
  38  * Private members of a ike_init_t task.
  39  */
  40 struct private_ike_init_t {
  41
  42         /**
  43          * Public methods and task_t interface.
  44          */
  45         ike_init_t public;
  46
  47         /**
  48          * Assigned IKE_SA.
  49          */
  50         ike_sa_t *ike_sa;
  51
  52         /**
  53          * Are we the initiator?
  54          */
  55         bool initiator;
  56
  57         /**
  58          * IKE config to establish
  59          */
  60         ike_cfg_t *config;
  61
  62         /**
  63          * diffie hellman group to use
  64          */
  65         diffie_hellman_group_t dh_group;
  66
  67         /**
  68          * diffie hellman key exchange
  69          */
  70         diffie_hellman_t *dh;
  71
  72         /**
  73          * Applying DH public value failed?
  74          */
  75         bool dh_failed;
  76
  77         /**
  78          * Keymat derivation (from IKE_SA)
  79          */
  80         keymat_v2_t *keymat;
  81
  82         /**
  83          * nonce chosen by us
  84          */
  85         chunk_t my_nonce;
  86
  87         /**
  88          * nonce chosen by peer
  89          */
  90         chunk_t other_nonce;
  91
  92         /**
  93          * nonce generator
  94          */
  95         nonce_gen_t *nonceg;
  96
  97         /**
  98          * Negotiated proposal used for IKE_SA
  99          */
 100         proposal_t *proposal;
 101
 102         /**
 103          * Old IKE_SA which gets rekeyed
 104          */
 105         ike_sa_t *old_sa;
 106
 107         /**
 108          * cookie received from responder
 109          */
 110         chunk_t cookie;
 111
 112         /**
 113          * retries done so far after failure (cookie or bad dh group)
 114          */
 115         u_int retry;
 116
 117         /**
 118          * Whether to use Signature Authentication as per RFC 7427
 119          */
 120         bool signature_authentication;
 121
 122         /**
 123          * Whether to follow IKEv2 redirects as per RFC 5685
 124          */
 125         bool follow_redirects;
 126 };
 127
 128 /**
 129  * Allocate our own nonce value
 130  */
 131 static bool generate_nonce(private_ike_init_t *this)
 132 {
 133         if (!this->nonceg)
 134         {
 135                 DBG1(DBG_IKE, "no nonce generator found to create nonce");
 136                 return FALSE;
 137         }
 138         if (!this->nonceg->allocate_nonce(this->nonceg, NONCE_SIZE,
 139                                                                           &this->my_nonce))
 140         {
 141                 DBG1(DBG_IKE, "nonce allocation failed");
 142                 return FALSE;
 143         }
 144         return TRUE;
 145 }
 146
 147 /**
 148  * Notify the peer about the hash algorithms we support or expect,
 149  * as per RFC 7427
 150  */
 151 static void send_supported_hash_algorithms(private_ike_init_t *this,
 152                                                                                    message_t *message)
 153 {
 154         hash_algorithm_set_t *algos;
 155         enumerator_t *enumerator, *rounds;
 156         bio_writer_t *writer;
 157         hash_algorithm_t hash;
 158         peer_cfg_t *peer;
 159         auth_cfg_t *auth;
 160         auth_rule_t rule;
 161         uintptr_t config;
 162         char *plugin_name;
 163
 164         algos = hash_algorithm_set_create();
 165         peer = this->ike_sa->get_peer_cfg(this->ike_sa);
 166         if (peer)
 167         {
 168                 rounds = peer->create_auth_cfg_enumerator(peer, FALSE);
 169                 while (rounds->enumerate(rounds, &auth))
 170                 {
 171                         enumerator = auth->create_enumerator(auth);
 172                         while (enumerator->enumerate(enumerator, &rule, &config))
 173                         {
 174                                 if (rule == AUTH_RULE_SIGNATURE_SCHEME)
 175                                 {
 176                                         hash = hasher_from_signature_scheme(config);
 177                                         if (hasher_algorithm_for_ikev2(hash))
 178                                         {
 179                                                 algos->add(algos, hash);
 180                                         }
 181                                 }
 182                         }
 183                         enumerator->destroy(enumerator);
 184                 }
 185                 rounds->destroy(rounds);
 186         }
 187
 188         if (!algos->count(algos))
 189         {
 190                 enumerator = lib->crypto->create_hasher_enumerator(lib->crypto);
 191                 while (enumerator->enumerate(enumerator, &hash, &plugin_name))
 192                 {
 193                         if (hasher_algorithm_for_ikev2(hash))
 194                         {
 195                                 algos->add(algos, hash);
 196                         }
 197                 }
 198                 enumerator->destroy(enumerator);
 199         }
 200
 201         if (algos->count(algos))
 202         {
 203                 writer = bio_writer_create(0);
 204                 enumerator = algos->create_enumerator(algos);
 205                 while (enumerator->enumerate(enumerator, &hash))
 206                 {
 207                         writer->write_uint16(writer, hash);
 208                 }
 209                 enumerator->destroy(enumerator);
 210                 message->add_notify(message, FALSE, SIGNATURE_HASH_ALGORITHMS,
 211                                                         writer->get_buf(writer));
 212                 writer->destroy(writer);
 213         }
 214         algos->destroy(algos);
 215 }
 216
 217 /**
 218  * Store algorithms supported by other peer
 219  */
 220 static void handle_supported_hash_algorithms(private_ike_init_t *this,
 221                                                                                          notify_payload_t *notify)
 222 {
 223         bio_reader_t *reader;
 224         u_int16_t algo;
 225         bool added = FALSE;
 226
 227         reader = bio_reader_create(notify->get_notification_data(notify));
 228         while (reader->remaining(reader) >= 2 && reader->read_uint16(reader, &algo))
 229         {
 230                 if (hasher_algorithm_for_ikev2(algo))
 231                 {
 232                         this->keymat->add_hash_algorithm(this->keymat, algo);
 233                         added = TRUE;
 234                 }
 235         }
 236         reader->destroy(reader);
 237
 238         if (added)
 239         {
 240                 this->ike_sa->enable_extension(this->ike_sa, EXT_SIGNATURE_AUTH);
 241         }
 242 }
 243
 244 /**
 245  * build the payloads for the message
 246  */
 247 static bool build_payloads(private_ike_init_t *this, message_t *message)
 248 {
 249         sa_payload_t *sa_payload;
 250         ke_payload_t *ke_payload;
 251         nonce_payload_t *nonce_payload;
 252         linked_list_t *proposal_list;
 253         ike_sa_id_t *id;
 254         proposal_t *proposal;
 255         enumerator_t *enumerator;
 256
 257         id = this->ike_sa->get_id(this->ike_sa);
 258
 259         this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
 260
 261         if (this->initiator)
 262         {
 263                 proposal_list = this->config->get_proposals(this->config);
 264                 if (this->old_sa)
 265                 {
 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))
 269                         {
 270                                 proposal->set_spi(proposal, id->get_initiator_spi(id));
 271                         }
 272                         enumerator->destroy(enumerator);
 273                 }
 274
 275                 sa_payload = sa_payload_create_from_proposals_v2(proposal_list);
 276                 proposal_list->destroy_offset(proposal_list, offsetof(proposal_t, destroy));
 277         }
 278         else
 279         {
 280                 if (this->old_sa)
 281                 {
 282                         /* include SPI of new IKE_SA when we are rekeying */
 283                         this->proposal->set_spi(this->proposal, id->get_responder_spi(id));
 284                 }
 285                 sa_payload = sa_payload_create_from_proposal_v2(this->proposal);
 286         }
 287         message->add_payload(message, (payload_t*)sa_payload);
 288
 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,
 292                                                                                                            this->dh);
 293         if (!ke_payload)
 294         {
 295                 DBG1(DBG_IKE, "creating KE payload failed");
 296                 return FALSE;
 297         }
 298
 299         if (this->old_sa)
 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);
 303         }
 304         else
 305         {
 306                 message->add_payload(message, (payload_t*)ke_payload);
 307                 message->add_payload(message, (payload_t*)nonce_payload);
 308         }
 309
 310         /* negotiate fragmentation if we are not rekeying */
 311         if (!this->old_sa &&
 312                  this->config->fragmentation(this->config) != FRAGMENTATION_NO)
 313         {
 314                 if (this->initiator ||
 315                         this->ike_sa->supports_extension(this->ike_sa,
 316                                                                                          EXT_IKE_FRAGMENTATION))
 317                 {
 318                         message->add_notify(message, FALSE, FRAGMENTATION_SUPPORTED,
 319                                                                 chunk_empty);
 320                 }
 321         }
 322         /* submit supported hash algorithms for signature authentication */
 323         if (!this->old_sa && this->signature_authentication)
 324         {
 325                 if (this->initiator ||
 326                         this->ike_sa->supports_extension(this->ike_sa,
 327                                                                                          EXT_SIGNATURE_AUTH))
 328                 {
 329                         send_supported_hash_algorithms(this, message);
 330                 }
 331         }
 332         /* notify other peer if we support redirection */
 333         if (!this->old_sa && this->initiator && this->follow_redirects)
 334         {
 335                 identification_t *gateway;
 336                 host_t *from;
 337                 chunk_t data;
 338
 339                 from = this->ike_sa->get_redirected_from(this->ike_sa);
 340                 if (from)
 341                 {
 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);
 346                         chunk_free(&data);
 347                         gateway->destroy(gateway);
 348                 }
 349                 else
 350                 {
 351                         message->add_notify(message, FALSE, REDIRECT_SUPPORTED,
 352                                                                 chunk_empty);
 353                 }
 354         }
 355         return TRUE;
 356 }
 357
 358 /**
 359  * Read payloads from message
 360  */
 361 static void process_payloads(private_ike_init_t *this, message_t *message)
 362 {
 363         enumerator_t *enumerator;
 364         payload_t *payload;
 365         ke_payload_t *ke_payload = NULL;
 366
 367         enumerator = message->create_payload_enumerator(message);
 368         while (enumerator->enumerate(enumerator, &payload))
 369         {
 370                 switch (payload->get_type(payload))
 371                 {
 372                         case PLV2_SECURITY_ASSOCIATION:
 373                         {
 374                                 sa_payload_t *sa_payload = (sa_payload_t*)payload;
 375                                 linked_list_t *proposal_list;
 376                                 bool private;
 377
 378                                 proposal_list = sa_payload->get_proposals(sa_payload);
 379                                 private = this->ike_sa->supports_extension(this->ike_sa,
 380                                                                                                                    EXT_STRONGSWAN);
 381                                 this->proposal = this->config->select_proposal(this->config,
 382                                                                                                                 proposal_list, private);
 383                                 if (!this->proposal)
 384                                 {
 385                                         charon->bus->alert(charon->bus, ALERT_PROPOSAL_MISMATCH_IKE,
 386                                                                            proposal_list);
 387                                 }
 388                                 proposal_list->destroy_offset(proposal_list,
 389                                                                                           offsetof(proposal_t, destroy));
 390                                 break;
 391                         }
 392                         case PLV2_KEY_EXCHANGE:
 393                         {
 394                                 ke_payload = (ke_payload_t*)payload;
 395
 396                                 this->dh_group = ke_payload->get_dh_group_number(ke_payload);
 397                                 break;
 398                         }
 399                         case PLV2_NONCE:
 400                         {
 401                                 nonce_payload_t *nonce_payload = (nonce_payload_t*)payload;
 402
 403                                 this->other_nonce = nonce_payload->get_nonce(nonce_payload);
 404                                 break;
 405                         }
 406                         case PLV2_NOTIFY:
 407                         {
 408                                 notify_payload_t *notify = (notify_payload_t*)payload;
 409
 410                                 switch (notify->get_notify_type(notify))
 411                                 {
 412                                         case FRAGMENTATION_SUPPORTED:
 413                                                 this->ike_sa->enable_extension(this->ike_sa,
 414                                                                                                            EXT_IKE_FRAGMENTATION);
 415                                                 break;
 416                                         case SIGNATURE_HASH_ALGORITHMS:
 417                                                 if (this->signature_authentication)
 418                                                 {
 419                                                         handle_supported_hash_algorithms(this, notify);
 420                                                 }
 421                                                 break;
 422                                         case REDIRECT_SUPPORTED:
 423                                                 this->ike_sa->enable_extension(this->ike_sa,
 424                                                                                                            EXT_IKE_REDIRECTION);
 425                                                 break;
 426                                         default:
 427                                                 /* other notifies are handled elsewhere */
 428                                                 break;
 429                                 }
 430
 431                         }
 432                         default:
 433                                 break;
 434                 }
 435         }
 436         enumerator->destroy(enumerator);
 437
 438         if (ke_payload && this->proposal &&
 439                 this->proposal->has_dh_group(this->proposal, this->dh_group))
 440         {
 441                 if (!this->initiator)
 442                 {
 443                         this->dh = this->keymat->keymat.create_dh(
 444                                                                 &this->keymat->keymat, this->dh_group);
 445                 }
 446                 if (this->dh)
 447                 {
 448                         this->dh_failed = !this->dh->set_other_public_value(this->dh,
 449                                                                 ke_payload->get_key_exchange_data(ke_payload));
 450                 }
 451         }
 452 }
 453
 454 METHOD(task_t, build_i, status_t,
 455         private_ike_init_t *this, message_t *message)
 456 {
 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);
 463
 464         if (this->retry >= MAX_RETRIES)
 465         {
 466                 DBG1(DBG_IKE, "giving up after %d retries", MAX_RETRIES);
 467                 return FAILED;
 468         }
 469
 470         /* if the DH group is set via use_dh_group(), we already have a DH object */
 471         if (!this->dh)
 472         {
 473                 this->dh_group = this->config->get_dh_group(this->config);
 474                 this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
 475                                                                                                   this->dh_group);
 476                 if (!this->dh)
 477                 {
 478                         DBG1(DBG_IKE, "configured DH group %N not supported",
 479                                 diffie_hellman_group_names, this->dh_group);
 480                         return FAILED;
 481                 }
 482         }
 483
 484         /* generate nonce only when we are trying the first time */
 485         if (this->my_nonce.ptr == NULL)
 486         {
 487                 if (!generate_nonce(this))
 488                 {
 489                         return FAILED;
 490                 }
 491         }
 492
 493         if (this->cookie.ptr)
 494         {
 495                 message->add_notify(message, FALSE, COOKIE, this->cookie);
 496         }
 497
 498         if (!build_payloads(this, message))
 499         {
 500                 return FAILED;
 501         }
 502
 503 #ifdef ME
 504         {
 505                 chunk_t connect_id = this->ike_sa->get_connect_id(this->ike_sa);
 506                 if (connect_id.ptr)
 507                 {
 508                         message->add_notify(message, FALSE, ME_CONNECTID, connect_id);
 509                 }
 510         }
 511 #endif /* ME */
 512
 513         return NEED_MORE;
 514 }
 515
 516 METHOD(task_t, process_r,  status_t,
 517         private_ike_init_t *this, message_t *message)
 518 {
 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);
 522
 523         if (!generate_nonce(this))
 524         {
 525                 return FAILED;
 526         }
 527
 528 #ifdef ME
 529         {
 530                 notify_payload_t *notify = message->get_notify(message, ME_CONNECTID);
 531                 if (notify)
 532                 {
 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,
 536                                                                                                  connect_id);
 537                 }
 538         }
 539 #endif /* ME */
 540
 541         process_payloads(this, message);
 542
 543         return NEED_MORE;
 544 }
 545
 546 /**
 547  * Derive the keymat for the IKE_SA
 548  */
 549 static bool derive_keys(private_ike_init_t *this,
 550                                                 chunk_t nonce_i, chunk_t nonce_r)
 551 {
 552         keymat_v2_t *old_keymat;
 553         pseudo_random_function_t prf_alg = PRF_UNDEFINED;
 554         chunk_t skd = chunk_empty;
 555         ike_sa_id_t *id;
 556
 557         id = this->ike_sa->get_id(this->ike_sa);
 558         if (this->old_sa)
 559         {
 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);
 563                 if (this->initiator)
 564                 {
 565                         id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
 566                 }
 567                 else
 568                 {
 569                         id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
 570                 }
 571         }
 572         if (!this->keymat->derive_ike_keys(this->keymat, this->proposal, this->dh,
 573                                                                            nonce_i, nonce_r, id, prf_alg, skd))
 574         {
 575                 return FALSE;
 576         }
 577         charon->bus->ike_keys(charon->bus, this->ike_sa, this->dh, chunk_empty,
 578                                                   nonce_i, nonce_r, this->old_sa, NULL);
 579         return TRUE;
 580 }
 581
 582 METHOD(task_t, build_r, status_t,
 583         private_ike_init_t *this, message_t *message)
 584 {
 585         identification_t *gateway;
 586
 587         /* check if we have everything we need */
 588         if (this->proposal == NULL ||
 589                 this->other_nonce.len == 0 || this->my_nonce.len == 0)
 590         {
 591                 DBG1(DBG_IKE, "received proposals inacceptable");
 592                 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
 593                 return FAILED;
 594         }
 595         this->ike_sa->set_proposal(this->ike_sa, this->proposal);
 596
 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,
 600                                                                                    &gateway))
 601         {
 602                 chunk_t data;
 603
 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);
 608                 chunk_free(&data);
 609                 return FAILED;
 610         }
 611
 612         if (this->dh == NULL ||
 613                 !this->proposal->has_dh_group(this->proposal, this->dh_group))
 614         {
 615                 u_int16_t group;
 616
 617                 if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
 618                                                                                   &group, NULL))
 619                 {
 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));
 627                 }
 628                 else
 629                 {
 630                         DBG1(DBG_IKE, "no acceptable proposal found");
 631                 }
 632                 return FAILED;
 633         }
 634
 635         if (this->dh_failed)
 636         {
 637                 DBG1(DBG_IKE, "applying DH public value failed");
 638                 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
 639                 return FAILED;
 640         }
 641
 642         if (!derive_keys(this, this->other_nonce, this->my_nonce))
 643         {
 644                 DBG1(DBG_IKE, "key derivation failed");
 645                 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
 646                 return FAILED;
 647         }
 648         if (!build_payloads(this, message))
 649         {
 650                 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
 651                 return FAILED;
 652         }
 653         return SUCCESS;
 654 }
 655
 656 /**
 657  * Raise alerts for received notify errors
 658  */
 659 static void raise_alerts(private_ike_init_t *this, notify_type_t type)
 660 {
 661         linked_list_t *list;
 662
 663         switch (type)
 664         {
 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));
 669                         break;
 670                 default:
 671                         break;
 672         }
 673 }
 674
 675 METHOD(task_t, process_i, status_t,
 676         private_ike_init_t *this, message_t *message)
 677 {
 678         enumerator_t *enumerator;
 679         payload_t *payload;
 680
 681         /* check for erroneous notifies */
 682         enumerator = message->create_payload_enumerator(message);
 683         while (enumerator->enumerate(enumerator, &payload))
 684         {
 685                 if (payload->get_type(payload) == PLV2_NOTIFY)
 686                 {
 687                         notify_payload_t *notify = (notify_payload_t*)payload;
 688                         notify_type_t type = notify->get_notify_type(notify);
 689
 690                         switch (type)
 691                         {
 692                                 case INVALID_KE_PAYLOAD:
 693                                 {
 694                                         chunk_t data;
 695                                         diffie_hellman_group_t bad_group;
 696
 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);
 703
 704                                         if (this->old_sa == NULL)
 705                                         {       /* reset the IKE_SA if we are not rekeying */
 706                                                 this->ike_sa->reset(this->ike_sa);
 707                                         }
 708
 709                                         enumerator->destroy(enumerator);
 710                                         this->retry++;
 711                                         return NEED_MORE;
 712                                 }
 713                                 case NAT_DETECTION_SOURCE_IP:
 714                                 case NAT_DETECTION_DESTINATION_IP:
 715                                         /* skip, handled in ike_natd_t */
 716                                         break;
 717                                 case MULTIPLE_AUTH_SUPPORTED:
 718                                         /* handled in ike_auth_t */
 719                                         break;
 720                                 case COOKIE:
 721                                 {
 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);
 727                                         this->retry++;
 728                                         return NEED_MORE;
 729                                 }
 730                                 case REDIRECT:
 731                                 {
 732                                         identification_t *gateway;
 733                                         chunk_t data, nonce = chunk_empty;
 734                                         status_t status = FAILED;
 735
 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))
 740                                         {
 741                                                 DBG1(DBG_IKE, "received invalid REDIRECT notify");
 742                                         }
 743                                         else if (this->ike_sa->handle_redirect(this->ike_sa,
 744                                                                                                                         gateway))
 745                                         {
 746                                                 status = NEED_MORE;
 747                                         }
 748                                         DESTROY_IF(gateway);
 749                                         chunk_free(&nonce);
 750                                         return status;
 751                                 }
 752                                 default:
 753                                 {
 754                                         if (type <= 16383)
 755                                         {
 756                                                 DBG1(DBG_IKE, "received %N notify error",
 757                                                          notify_type_names, type);
 758                                                 enumerator->destroy(enumerator);
 759                                                 raise_alerts(this, type);
 760                                                 return FAILED;
 761                                         }
 762                                         DBG2(DBG_IKE, "received %N notify",
 763                                                 notify_type_names, type);
 764                                         break;
 765                                 }
 766                         }
 767                 }
 768         }
 769         enumerator->destroy(enumerator);
 770
 771         process_payloads(this, message);
 772
 773         /* check if we have everything */
 774         if (this->proposal == NULL ||
 775                 this->other_nonce.len == 0 || this->my_nonce.len == 0)
 776         {
 777                 DBG1(DBG_IKE, "peers proposal selection invalid");
 778                 return FAILED;
 779         }
 780         this->ike_sa->set_proposal(this->ike_sa, this->proposal);
 781
 782         if (this->dh == NULL ||
 783                 !this->proposal->has_dh_group(this->proposal, this->dh_group))
 784         {
 785                 DBG1(DBG_IKE, "peer DH group selection invalid");
 786                 return FAILED;
 787         }
 788
 789         if (this->dh_failed)
 790         {
 791                 DBG1(DBG_IKE, "applying DH public value failed");
 792                 return FAILED;
 793         }
 794
 795         if (!derive_keys(this, this->my_nonce, this->other_nonce))
 796         {
 797                 DBG1(DBG_IKE, "key derivation failed");
 798                 return FAILED;
 799         }
 800         return SUCCESS;
 801 }
 802
 803 METHOD(task_t, get_type, task_type_t,
 804         private_ike_init_t *this)
 805 {
 806         return TASK_IKE_INIT;
 807 }
 808
 809 METHOD(task_t, migrate, void,
 810         private_ike_init_t *this, ike_sa_t *ike_sa)
 811 {
 812         DESTROY_IF(this->proposal);
 813         chunk_free(&this->other_nonce);
 814
 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,
 823                                                                                                   this->dh_group);
 824         }
 825 }
 826
 827 METHOD(task_t, destroy, void,
 828         private_ike_init_t *this)
 829 {
 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);
 836         free(this);
 837 }
 838
 839 METHOD(ike_init_t, get_lower_nonce, chunk_t,
 840         private_ike_init_t *this)
 841 {
 842         if (memcmp(this->my_nonce.ptr, this->other_nonce.ptr,
 843                            min(this->my_nonce.len, this->other_nonce.len)) < 0)
 844         {
 845                 return this->my_nonce;
 846         }
 847         else
 848         {
 849                 return this->other_nonce;
 850         }
 851 }
 852
 853 /*
 854  * Described in header.
 855  */
 856 ike_init_t *ike_init_create(ike_sa_t *ike_sa, bool initiator, ike_sa_t *old_sa)
 857 {
 858         private_ike_init_t *this;
 859
 860         INIT(this,
 861                 .public = {
 862                         .task = {
 863                                 .get_type = _get_type,
 864                                 .migrate = _migrate,
 865                                 .destroy = _destroy,
 866                         },
 867                         .get_lower_nonce = _get_lower_nonce,
 868                 },
 869                 .ike_sa = ike_sa,
 870                 .initiator = initiator,
 871                 .dh_group = MODP_NONE,
 872                 .keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa),
 873                 .old_sa = old_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),
 878         );
 879         this->nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat);
 880
 881         if (initiator)
 882         {
 883                 this->public.task.build = _build_i;
 884                 this->public.task.process = _process_i;
 885         }
 886         else
 887         {
 888                 this->public.task.build = _build_r;
 889                 this->public.task.process = _process_r;
 890         }
 891         return &this->public;
 892 }