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

   1 /*
   2  * Copyright (C) 2005-2008 Martin Willi
   3  * Copyright (C) 2005 Jan Hutter
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #include "ike_rekey.h"
  18
  19 #include <daemon.h>
  20 #include <encoding/payloads/notify_payload.h>
  21 #include <sa/ikev2/tasks/ike_init.h>
  22 #include <sa/ikev2/tasks/ike_delete.h>
  23 #include <processing/jobs/delete_ike_sa_job.h>
  24 #include <processing/jobs/rekey_ike_sa_job.h>
  25
  26
  27 typedef struct private_ike_rekey_t private_ike_rekey_t;
  28
  29 /**
  30  * Private members of a ike_rekey_t task.
  31  */
  32 struct private_ike_rekey_t {
  33
  34         /**
  35          * Public methods and task_t interface.
  36          */
  37         ike_rekey_t public;
  38
  39         /**
  40          * Assigned IKE_SA.
  41          */
  42         ike_sa_t *ike_sa;
  43
  44         /**
  45          * New IKE_SA which replaces the current one
  46          */
  47         ike_sa_t *new_sa;
  48
  49         /**
  50          * Are we the initiator?
  51          */
  52         bool initiator;
  53
  54         /**
  55          * the TASK_IKE_INIT task which is reused to simplify rekeying
  56          */
  57         ike_init_t *ike_init;
  58
  59         /**
  60          * IKE_DELETE task to delete the old IKE_SA after rekeying was successful
  61          */
  62         ike_delete_t *ike_delete;
  63
  64         /**
  65          * colliding task detected by the task manager
  66          */
  67         task_t *collision;
  68 };
  69
  70 /**
  71  * Establish the new replacement IKE_SA
  72  */
  73 static void establish_new(private_ike_rekey_t *this)
  74 {
  75         if (this->new_sa)
  76         {
  77                 this->new_sa->set_state(this->new_sa, IKE_ESTABLISHED);
  78                 DBG0(DBG_IKE, "IKE_SA %s[%d] rekeyed between %H[%Y]...%H[%Y]",
  79                          this->new_sa->get_name(this->new_sa),
  80                          this->new_sa->get_unique_id(this->new_sa),
  81                          this->ike_sa->get_my_host(this->ike_sa),
  82                          this->ike_sa->get_my_id(this->ike_sa),
  83                          this->ike_sa->get_other_host(this->ike_sa),
  84                          this->ike_sa->get_other_id(this->ike_sa));
  85
  86                 this->new_sa->inherit(this->new_sa, this->ike_sa);
  87                 charon->bus->ike_rekey(charon->bus, this->ike_sa, this->new_sa);
  88                 charon->ike_sa_manager->checkin(charon->ike_sa_manager, this->new_sa);
  89                 this->new_sa = NULL;
  90                 /* set threads active IKE_SA after checkin */
  91                 charon->bus->set_sa(charon->bus, this->ike_sa);
  92         }
  93 }
  94
  95 METHOD(task_t, process_r_delete, status_t,
  96         private_ike_rekey_t *this, message_t *message)
  97 {
  98         establish_new(this);
  99         return this->ike_delete->task.process(&this->ike_delete->task, message);
 100 }
 101
 102 METHOD(task_t, build_r_delete, status_t,
 103         private_ike_rekey_t *this, message_t *message)
 104 {
 105         return this->ike_delete->task.build(&this->ike_delete->task, message);
 106 }
 107
 108 METHOD(task_t, build_i_delete, status_t,
 109         private_ike_rekey_t *this, message_t *message)
 110 {
 111         /* update exchange type to INFORMATIONAL for the delete */
 112         message->set_exchange_type(message, INFORMATIONAL);
 113
 114         return this->ike_delete->task.build(&this->ike_delete->task, message);
 115 }
 116
 117 METHOD(task_t, process_i_delete, status_t,
 118         private_ike_rekey_t *this, message_t *message)
 119 {
 120         return this->ike_delete->task.process(&this->ike_delete->task, message);
 121 }
 122
 123 METHOD(task_t, build_i, status_t,
 124         private_ike_rekey_t *this, message_t *message)
 125 {
 126         ike_version_t version;
 127         peer_cfg_t *peer_cfg;
 128         host_t *other_host;
 129
 130         /* create new SA only on first try */
 131         if (this->new_sa == NULL)
 132         {
 133                 version = this->ike_sa->get_version(this->ike_sa);
 134                 this->new_sa = charon->ike_sa_manager->checkout_new(
 135                                                                                 charon->ike_sa_manager, version, TRUE);
 136                 if (!this->new_sa)
 137                 {       /* shouldn't happen */
 138                         return FAILED;
 139                 }
 140                 peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
 141                 other_host = this->ike_sa->get_other_host(this->ike_sa);
 142                 this->new_sa->set_peer_cfg(this->new_sa, peer_cfg);
 143                 this->new_sa->set_other_host(this->new_sa, other_host->clone(other_host));
 144                 this->ike_init = ike_init_create(this->new_sa, TRUE, this->ike_sa);
 145                 this->ike_sa->set_state(this->ike_sa, IKE_REKEYING);
 146         }
 147         this->ike_init->task.build(&this->ike_init->task, message);
 148
 149         return NEED_MORE;
 150 }
 151
 152 METHOD(task_t, process_r, status_t,
 153         private_ike_rekey_t *this, message_t *message)
 154 {
 155         enumerator_t *enumerator;
 156         peer_cfg_t *peer_cfg;
 157         child_sa_t *child_sa;
 158
 159         if (this->ike_sa->get_state(this->ike_sa) == IKE_DELETING)
 160         {
 161                 DBG1(DBG_IKE, "peer initiated rekeying, but we are deleting");
 162                 return NEED_MORE;
 163         }
 164
 165         enumerator = this->ike_sa->create_child_sa_enumerator(this->ike_sa);
 166         while (enumerator->enumerate(enumerator, (void**)&child_sa))
 167         {
 168                 switch (child_sa->get_state(child_sa))
 169                 {
 170                         case CHILD_CREATED:
 171                         case CHILD_REKEYING:
 172                         case CHILD_DELETING:
 173                                 /* we do not allow rekeying while we have children in-progress */
 174                                 DBG1(DBG_IKE, "peer initiated rekeying, but a child is half-open");
 175                                 enumerator->destroy(enumerator);
 176                                 return NEED_MORE;
 177                         default:
 178                                 break;
 179                 }
 180         }
 181         enumerator->destroy(enumerator);
 182
 183         this->new_sa = charon->ike_sa_manager->checkout_new(charon->ike_sa_manager,
 184                                                         this->ike_sa->get_version(this->ike_sa), FALSE);
 185         if (!this->new_sa)
 186         {       /* shouldn't happen */
 187                 return FAILED;
 188         }
 189
 190         peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
 191         this->new_sa->set_peer_cfg(this->new_sa, peer_cfg);
 192         this->ike_init = ike_init_create(this->new_sa, FALSE, this->ike_sa);
 193         this->ike_init->task.process(&this->ike_init->task, message);
 194
 195         return NEED_MORE;
 196 }
 197
 198 METHOD(task_t, build_r, status_t,
 199         private_ike_rekey_t *this, message_t *message)
 200 {
 201         if (this->new_sa == NULL)
 202         {
 203                 /* IKE_SA/a CHILD_SA is in an inacceptable state, deny rekeying */
 204                 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
 205                 return SUCCESS;
 206         }
 207
 208         if (this->ike_init->task.build(&this->ike_init->task, message) == FAILED)
 209         {
 210                 return SUCCESS;
 211         }
 212
 213         this->ike_sa->set_state(this->ike_sa, IKE_REKEYING);
 214
 215         /* rekeying successful, delete the IKE_SA using a subtask */
 216         this->ike_delete = ike_delete_create(this->ike_sa, FALSE);
 217         this->public.task.build = _build_r_delete;
 218         this->public.task.process = _process_r_delete;
 219
 220         return NEED_MORE;
 221 }
 222
 223 METHOD(task_t, process_i, status_t,
 224         private_ike_rekey_t *this, message_t *message)
 225 {
 226         if (message->get_notify(message, NO_ADDITIONAL_SAS))
 227         {
 228                 DBG1(DBG_IKE, "peer seems to not support IKE rekeying, "
 229                          "starting reauthentication");
 230                 this->ike_sa->set_state(this->ike_sa, IKE_ESTABLISHED);
 231                 lib->processor->queue_job(lib->processor,
 232                                 (job_t*)rekey_ike_sa_job_create(
 233                                                         this->ike_sa->get_id(this->ike_sa), TRUE));
 234                 return SUCCESS;
 235         }
 236
 237         switch (this->ike_init->task.process(&this->ike_init->task, message))
 238         {
 239                 case FAILED:
 240                         /* rekeying failed, fallback to old SA */
 241                         if (!(this->collision && (
 242                                 this->collision->get_type(this->collision) == TASK_IKE_DELETE ||
 243                                 this->collision->get_type(this->collision) == TASK_IKE_REAUTH)))
 244                         {
 245                                 job_t *job;
 246                                 u_int32_t retry = RETRY_INTERVAL - (random() % RETRY_JITTER);
 247                                 job = (job_t*)rekey_ike_sa_job_create(
 248                                                                                 this->ike_sa->get_id(this->ike_sa), FALSE);
 249                                 DBG1(DBG_IKE, "IKE_SA rekeying failed, "
 250                                                                                 "trying again in %d seconds", retry);
 251                                 this->ike_sa->set_state(this->ike_sa, IKE_ESTABLISHED);
 252                                 lib->scheduler->schedule_job(lib->scheduler, job, retry);
 253                         }
 254                         return SUCCESS;
 255                 case NEED_MORE:
 256                         /* bad dh group, try again */
 257                         this->ike_init->task.migrate(&this->ike_init->task, this->new_sa);
 258                         return NEED_MORE;
 259                 default:
 260                         break;
 261         }
 262
 263         /* check for collisions */
 264         if (this->collision &&
 265                 this->collision->get_type(this->collision) == TASK_IKE_REKEY)
 266         {
 267                 private_ike_rekey_t *other = (private_ike_rekey_t*)this->collision;
 268
 269                 /* ike_init can be NULL, if child_sa is half-open */
 270                 if (other->ike_init)
 271                 {
 272                         host_t *host;
 273                         chunk_t this_nonce, other_nonce;
 274
 275                         this_nonce = this->ike_init->get_lower_nonce(this->ike_init);
 276                         other_nonce = other->ike_init->get_lower_nonce(other->ike_init);
 277
 278                         /* if we have the lower nonce, delete rekeyed SA. If not, delete
 279                          * the redundant. */
 280                         if (memcmp(this_nonce.ptr, other_nonce.ptr,
 281                                                 min(this_nonce.len, other_nonce.len)) > 0)
 282                         {
 283                                 /* peer should delete this SA. Add a timeout just in case. */
 284                                 job_t *job = (job_t*)delete_ike_sa_job_create(
 285                                                 other->new_sa->get_id(other->new_sa), TRUE);
 286                                 lib->scheduler->schedule_job(lib->scheduler, job, 10);
 287                                 DBG1(DBG_IKE, "IKE_SA rekey collision won, waiting for delete");
 288                                 charon->ike_sa_manager->checkin(charon->ike_sa_manager, other->new_sa);
 289                                 other->new_sa = NULL;
 290                         }
 291                         else
 292                         {
 293                                 DBG1(DBG_IKE, "IKE_SA rekey collision lost, "
 294                                          "deleting redundant IKE_SA");
 295                                 /* apply host for a proper delete */
 296                                 host = this->ike_sa->get_my_host(this->ike_sa);
 297                                 this->new_sa->set_my_host(this->new_sa, host->clone(host));
 298                                 host = this->ike_sa->get_other_host(this->ike_sa);
 299                                 this->new_sa->set_other_host(this->new_sa, host->clone(host));
 300                                 this->ike_sa->set_state(this->ike_sa, IKE_ESTABLISHED);
 301                                 this->new_sa->set_state(this->new_sa, IKE_REKEYING);
 302                                 if (this->new_sa->delete(this->new_sa) == DESTROY_ME)
 303                                 {
 304                                         this->new_sa->destroy(this->new_sa);
 305                                 }
 306                                 else
 307                                 {
 308                                         charon->ike_sa_manager->checkin(
 309                                                                 charon->ike_sa_manager, this->new_sa);
 310                                         /* set threads active IKE_SA after checkin */
 311                                         charon->bus->set_sa(charon->bus, this->ike_sa);
 312                                 }
 313                                 this->new_sa = NULL;
 314                                 establish_new(other);
 315                                 return SUCCESS;
 316                         }
 317                 }
 318                 /* set threads active IKE_SA after checkin */
 319                 charon->bus->set_sa(charon->bus, this->ike_sa);
 320         }
 321
 322         establish_new(this);
 323
 324         /* rekeying successful, delete the IKE_SA using a subtask */
 325         this->ike_delete = ike_delete_create(this->ike_sa, TRUE);
 326         this->public.task.build = _build_i_delete;
 327         this->public.task.process = _process_i_delete;
 328
 329         return NEED_MORE;
 330 }
 331
 332 METHOD(task_t, get_type, task_type_t,
 333         private_ike_rekey_t *this)
 334 {
 335         return TASK_IKE_REKEY;
 336 }
 337
 338 METHOD(ike_rekey_t, collide, void,
 339         private_ike_rekey_t* this, task_t *other)
 340 {
 341         DBG1(DBG_IKE, "detected %N collision with %N", task_type_names,
 342                  TASK_IKE_REKEY, task_type_names, other->get_type(other));
 343         DESTROY_IF(this->collision);
 344         this->collision = other;
 345 }
 346
 347 METHOD(task_t, migrate, void,
 348         private_ike_rekey_t *this, ike_sa_t *ike_sa)
 349 {
 350         if (this->ike_init)
 351         {
 352                 this->ike_init->task.destroy(&this->ike_init->task);
 353         }
 354         if (this->ike_delete)
 355         {
 356                 this->ike_delete->task.destroy(&this->ike_delete->task);
 357         }
 358         DESTROY_IF(this->new_sa);
 359         DESTROY_IF(this->collision);
 360
 361         this->collision = NULL;
 362         this->ike_sa = ike_sa;
 363         this->new_sa = NULL;
 364         this->ike_init = NULL;
 365         this->ike_delete = NULL;
 366 }
 367
 368 METHOD(task_t, destroy, void,
 369         private_ike_rekey_t *this)
 370 {
 371         if (this->ike_init)
 372         {
 373                 this->ike_init->task.destroy(&this->ike_init->task);
 374         }
 375         if (this->ike_delete)
 376         {
 377                 this->ike_delete->task.destroy(&this->ike_delete->task);
 378         }
 379         DESTROY_IF(this->new_sa);
 380         DESTROY_IF(this->collision);
 381         free(this);
 382 }
 383
 384 /*
 385  * Described in header.
 386  */
 387 ike_rekey_t *ike_rekey_create(ike_sa_t *ike_sa, bool initiator)
 388 {
 389         private_ike_rekey_t *this;
 390
 391         INIT(this,
 392                 .public = {
 393                         .task = {
 394                                 .get_type = _get_type,
 395                                 .build = _build_r,
 396                                 .process = _process_r,
 397                                 .migrate = _migrate,
 398                                 .destroy = _destroy,
 399                         },
 400                         .collide = _collide,
 401                 },
 402                 .ike_sa = ike_sa,
 403                 .initiator = initiator,
 404         );
 405         if (initiator)
 406         {
 407                 this->public.task.build = _build_i;
 408                 this->public.task.process = _process_i;
 409         }
 410
 411         return &this->public;
 412 }