Task added for IKEv1 NAT detection.
authorTobias Brunner <tobias@strongswan.org>
Wed, 30 Nov 2011 16:09:42 +0000 (17:09 +0100)
committerTobias Brunner <tobias@strongswan.org>
Tue, 20 Mar 2012 16:31:10 +0000 (17:31 +0100)
There is already support for both Main and Aggressive Mode.

src/libcharon/Makefile.am
src/libcharon/sa/ike_sa.c
src/libcharon/sa/task_manager_v1.c
src/libcharon/sa/tasks/ike_natd_v1.c [new file with mode: 0644]
src/libcharon/sa/tasks/ike_natd_v1.h [new file with mode: 0644]
src/libcharon/sa/tasks/task.c
src/libcharon/sa/tasks/task.h

index 5387749..aab293d 100644 (file)
@@ -85,6 +85,7 @@ sa/tasks/ike_delete.c sa/tasks/ike_delete.h \
 sa/tasks/ike_dpd.c sa/tasks/ike_dpd.h \
 sa/tasks/ike_init.c sa/tasks/ike_init.h \
 sa/tasks/ike_natd.c sa/tasks/ike_natd.h \
+sa/tasks/ike_natd_v1.c sa/tasks/ike_natd_v1.h \
 sa/tasks/ike_mobike.c sa/tasks/ike_mobike.h \
 sa/tasks/ike_rekey.c sa/tasks/ike_rekey.h \
 sa/tasks/ike_reauth.c sa/tasks/ike_reauth.h \
@@ -93,8 +94,9 @@ sa/tasks/ike_vendor.c sa/tasks/ike_vendor.h \
 sa/tasks/ike_vendor_v1.c sa/tasks/ike_vendor_v1.h \
 sa/tasks/main_mode.c sa/tasks/main_mode.h \
 sa/tasks/quick_mode.c sa/tasks/quick_mode.h \
-sa/tasks/task.c sa/tasks/task.h \
-sa/tasks/xauth_request.c sa/tasks/xauth_request.h
+sa/tasks/xauth_request.c sa/tasks/xauth_request.h \
+sa/tasks/task.c sa/tasks/task.h
+
 
 daemon.lo :            $(top_builddir)/config.status
 
index 0990111..5a21a88 100644 (file)
@@ -46,6 +46,7 @@
 #include <sa/tasks/child_rekey.h>
 #include <sa/tasks/main_mode.h>
 #include <sa/tasks/quick_mode.h>
+#include <sa/tasks/ike_natd_v1.h>
 #include <sa/tasks/ike_vendor_v1.h>
 #include <sa/tasks/xauth_request.h>
 #include <processing/jobs/retransmit_job.h>
@@ -1123,6 +1124,8 @@ METHOD(ike_sa_t, initiate, status_t,
                        this->task_manager->queue_task(this->task_manager, task);
                        task = (task_t*)main_mode_create(&this->public, TRUE);
                        this->task_manager->queue_task(this->task_manager, task);
+                       task = (task_t*)ike_natd_v1_create(&this->public, TRUE);
+                       this->task_manager->queue_task(this->task_manager, task);
                }
                else
                {
index 9008b60..18decb6 100644 (file)
 #include <math.h>
 
 #include <daemon.h>
-#include <sa/tasks/ike_vendor.h>
 #include <sa/tasks/main_mode.h>
 #include <sa/tasks/quick_mode.h>
 #include <sa/tasks/xauth_request.h>
+#include <sa/tasks/ike_natd_v1.h>
 #include <sa/tasks/ike_vendor_v1.h>
 #include <processing/jobs/retransmit_job.h>
 #include <processing/jobs/delete_ike_sa_job.h>
@@ -267,6 +267,7 @@ METHOD(task_manager_t, initiate, status_t,
                                if (activate_task(this, TASK_MAIN_MODE))
                                {
                                        exchange = ID_PROT;
+                                       activate_task(this, TASK_IKE_NATD_V1);
                                }
                                break;
                        case IKE_CONNECTING:
@@ -497,6 +498,8 @@ static status_t process_request(private_task_manager_t *this,
                                this->passive_tasks->insert_last(this->passive_tasks, task);
                                task = (task_t *)main_mode_create(this->ike_sa, FALSE);
                                this->passive_tasks->insert_last(this->passive_tasks, task);
+                               task = (task_t *)ike_natd_v1_create(this->ike_sa, FALSE);
+                               this->passive_tasks->insert_last(this->passive_tasks, task);
                                break;
                        case AGGRESSIVE:
                                /* TODO-IKEv1: agressive mode */
diff --git a/src/libcharon/sa/tasks/ike_natd_v1.c b/src/libcharon/sa/tasks/ike_natd_v1.c
new file mode 100644 (file)
index 0000000..d7f957d
--- /dev/null
@@ -0,0 +1,440 @@
+/*
+ * Copyright (C) 2006-2011 Tobias Brunner,
+ * Copyright (C) 2006-2007 Martin Willi
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "ike_natd_v1.h"
+
+#include <string.h>
+
+#include <hydra.h>
+#include <daemon.h>
+#include <sa/keymat_v1.h>
+#include <config/peer_cfg.h>
+#include <crypto/hashers/hasher.h>
+#include <encoding/payloads/hash_payload.h>
+
+typedef struct private_ike_natd_v1_t private_ike_natd_v1_t;
+
+/**
+ * Private members of a ike_natt_t task.
+ */
+struct private_ike_natd_v1_t {
+
+       /**
+        * Public interface.
+        */
+       ike_natd_v1_t public;
+
+       /**
+        * Assigned IKE_SA.
+        */
+       ike_sa_t *ike_sa;
+
+       /**
+        * Are we the initiator?
+        */
+       bool initiator;
+
+       /**
+        * Keymat derivation (from SA)
+        */
+       keymat_v1_t *keymat;
+
+       /**
+        * Did we process any NAT detection payloads for a source address?
+        */
+       bool src_seen;
+
+       /**
+        * Did we process any NAT detection payloads for a destination address?
+        */
+       bool dst_seen;
+
+       /**
+        * Have we found a matching source address NAT hash?
+        */
+       bool src_matched;
+
+       /**
+        * Have we found a matching destination address NAT hash?
+        */
+       bool dst_matched;
+};
+
+/**
+ * Build NAT detection hash for a host.
+ */
+static chunk_t generate_natd_hash(private_ike_natd_v1_t *this,
+                                                                 ike_sa_id_t *ike_sa_id, host_t *host)
+{
+       hasher_t *hasher;
+       chunk_t natd_chunk, natd_hash;
+       u_int64_t spi_i, spi_r;
+       u_int16_t port;
+
+       hasher = this->keymat->get_hasher(this->keymat);
+       if (!hasher)
+       {
+               DBG1(DBG_IKE, "no hasher available to build NAT-D payload");
+               return chunk_empty;
+       }
+
+       spi_i = ike_sa_id->get_initiator_spi(ike_sa_id);
+       spi_r = ike_sa_id->get_responder_spi(ike_sa_id);
+       port = htons(host->get_port(host));
+
+       /*  natd_hash = HASH(CKY-I | CKY-R | IP | Port) */
+       natd_chunk = chunk_cata("cccc", chunk_from_thing(spi_i),
+                                                   chunk_from_thing(spi_r), host->get_address(host),
+                                                   chunk_from_thing(port));
+       hasher->allocate_hash(hasher, natd_chunk, &natd_hash);
+       DBG3(DBG_IKE, "natd_chunk %B", &natd_chunk);
+       DBG3(DBG_IKE, "natd_hash %B", &natd_hash);
+
+       return natd_hash;
+}
+
+/**
+ * Build a faked NAT-D payload to enforce UDP encapsulation.
+ */
+static chunk_t generate_natd_hash_faked(private_ike_natd_v1_t *this)
+{
+       hasher_t *hasher;
+       chunk_t chunk;
+       rng_t *rng;
+
+       hasher = this->keymat->get_hasher(this->keymat);
+       if (!hasher)
+       {
+               DBG1(DBG_IKE, "no hasher available to build NAT-D payload");
+               return chunk_empty;
+       }
+       rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
+       if (!rng)
+       {
+               DBG1(DBG_IKE, "unable to get random bytes for NAT-D fake");
+               return chunk_empty;
+       }
+       rng->allocate_bytes(rng, hasher->get_hash_size(hasher), &chunk);
+       rng->destroy(rng);
+       return chunk;
+}
+
+/**
+ * Build a NAT-D payload.
+ */
+static hash_payload_t *build_natd_payload(private_ike_natd_v1_t *this, bool src,
+                                                                                 host_t *host)
+{
+       hash_payload_t *payload;
+       ike_cfg_t *config;
+       chunk_t hash;
+
+       config = this->ike_sa->get_ike_cfg(this->ike_sa);
+       if (src && config->force_encap(config))
+       {
+               hash = generate_natd_hash_faked(this);
+       }
+       else
+       {
+               ike_sa_id_t *ike_sa_id = this->ike_sa->get_id(this->ike_sa);
+               hash = generate_natd_hash(this, ike_sa_id, host);
+       }
+       payload = hash_payload_create(NAT_D_V1);
+       payload->set_hash(payload, hash);
+       chunk_free(&hash);
+       return payload;
+}
+
+/**
+ * Add NAT-D payloads to the message.
+ */
+static void add_natd_payloads(private_ike_natd_v1_t *this, message_t *message)
+{
+       hash_payload_t *payload;
+       host_t *host;
+
+       /* destination has to be added first */
+       host = message->get_destination(message);
+       payload = build_natd_payload(this, FALSE, host);
+       message->add_payload(message, (payload_t*)payload);
+
+       /* source is added second, compared with IKEv2 we always know the source,
+        * as these payloads are added in the second Phase 1 exchange or the
+        * response to the first */
+       host = message->get_source(message);
+       payload = build_natd_payload(this, TRUE, host);
+       message->add_payload(message, (payload_t*)payload);
+}
+
+/**
+ * Read NAT-D payloads from message and evaluate them.
+ */
+static void process_payloads(private_ike_natd_v1_t *this, message_t *message)
+{
+       enumerator_t *enumerator;
+       payload_t *payload;
+       hash_payload_t *hash_payload;
+       chunk_t hash, src_hash, dst_hash;
+       ike_sa_id_t *ike_sa_id;
+       host_t *me, *other;
+       ike_cfg_t *config;
+
+       /* precompute hashes for incoming NAT-D comparison */
+       ike_sa_id = message->get_ike_sa_id(message);
+       me = message->get_destination(message);
+       other = message->get_source(message);
+       dst_hash = generate_natd_hash(this, ike_sa_id, me);
+       src_hash = generate_natd_hash(this, ike_sa_id, other);
+
+       DBG3(DBG_IKE, "precalculated src_hash %B", &src_hash);
+       DBG3(DBG_IKE, "precalculated dst_hash %B", &dst_hash);
+
+       enumerator = message->create_payload_enumerator(message);
+       while (enumerator->enumerate(enumerator, &payload))
+       {
+               if (payload->get_type(payload) != NAT_D_V1)
+               {
+                       continue;
+               }
+               hash_payload = (hash_payload_t*)payload;
+               if (!this->dst_seen)
+               {       /* the first NAT-D payload contains the destination hash */
+                       this->dst_seen = TRUE;
+                       hash = hash_payload->get_hash(hash_payload);
+                       DBG3(DBG_IKE, "received dst_hash %B", &hash);
+                       if (chunk_equals(hash, dst_hash))
+                       {
+                               this->dst_matched = TRUE;
+                       }
+                       continue;
+               }
+               /* the other NAT-D payloads contain source hashes */
+               this->src_seen = TRUE;
+               if (!this->src_matched)
+               {
+                       hash = hash_payload->get_hash(hash_payload);
+                       DBG3(DBG_IKE, "received src_hash %B", &hash);
+                       if (chunk_equals(hash, src_hash))
+                       {
+                               this->src_matched = TRUE;
+                       }
+               }
+       }
+       enumerator->destroy(enumerator);
+
+       chunk_free(&src_hash);
+       chunk_free(&dst_hash);
+
+       if (this->src_seen && this->dst_seen)
+       {
+               this->ike_sa->set_condition(this->ike_sa, COND_NAT_HERE,
+                                                                       !this->dst_matched);
+               this->ike_sa->set_condition(this->ike_sa, COND_NAT_THERE,
+                                                                       !this->src_matched);
+               config = this->ike_sa->get_ike_cfg(this->ike_sa);
+               if (this->dst_matched && this->src_matched &&
+                       config->force_encap(config))
+               {
+                       this->ike_sa->set_condition(this->ike_sa, COND_NAT_FAKE, TRUE);
+               }
+       }
+}
+
+METHOD(task_t, build_i, status_t,
+       private_ike_natd_v1_t *this, message_t *message)
+{
+       status_t result = NEED_MORE;
+
+       switch (message->get_exchange_type(message))
+       {
+               case AGGRESSIVE:
+               {       /* add NAT-D payloads to the second request, already processed
+                        * those by the responder contained in the first response */
+                       result = SUCCESS;
+                       /* fall */
+               }
+               case ID_PROT:
+               {       /* add NAT-D payloads to the second request, need to process
+                        * those by the responder contained in the second response */
+                       if (message->get_payload(message, SECURITY_ASSOCIATION_V1))
+                       {       /* wait for the second exchange */
+                               return NEED_MORE;
+                       }
+                       add_natd_payloads(this, message);
+                       return result;
+               }
+               default:
+                       break;
+       }
+       return SUCCESS;
+}
+
+METHOD(task_t, process_i, status_t,
+       private_ike_natd_v1_t *this, message_t *message)
+{
+       status_t result = NEED_MORE;
+
+       if (!this->ike_sa->supports_extension(this->ike_sa, EXT_NATT))
+       {       /* we didn't receive VIDs inidcating support for NAT-T */
+               return SUCCESS;
+       }
+
+       switch (message->get_exchange_type(message))
+       {
+               case ID_PROT:
+               {       /* process NAT-D payloads in the second response, added them in the
+                        * second request already, so we're done afterwards */
+                       if (message->get_payload(message, SECURITY_ASSOCIATION_V1))
+                       {       /* wait for the second exchange */
+                               return NEED_MORE;
+                       }
+                       result = SUCCESS;
+                       /* fall */
+               }
+               case AGGRESSIVE:
+               {       /* process NAT-D payloads in the first response, add them in the
+                        * following second request */
+                       process_payloads(this, message);
+
+                       if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY))
+                       {
+                               this->ike_sa->float_ports(this->ike_sa);
+                       }
+                       return result;
+               }
+               default:
+                       break;
+       }
+       return SUCCESS;
+}
+
+METHOD(task_t, process_r, status_t,
+       private_ike_natd_v1_t *this, message_t *message)
+{
+       status_t result = NEED_MORE;
+
+       if (!this->ike_sa->supports_extension(this->ike_sa, EXT_NATT))
+       {       /* we didn't receive VIDs indicating NAT-T support */
+               return SUCCESS;
+       }
+
+       switch (message->get_exchange_type(message))
+       {
+               case AGGRESSIVE:
+               {       /* proccess NAT-D payloads in the second request, already added ours
+                        * in the first response */
+                       result = SUCCESS;
+                       /* fall */
+               }
+               case ID_PROT:
+               {       /* process NAT-D payloads in the second request, need to add ours
+                        * to the second response */
+                       if (message->get_payload(message, SECURITY_ASSOCIATION_V1))
+                       {       /* wait for the second exchange */
+                               return NEED_MORE;
+                       }
+                       process_payloads(this, message);
+                       return result;
+               }
+               default:
+                       break;
+       }
+       return SUCCESS;
+}
+
+METHOD(task_t, build_r, status_t,
+       private_ike_natd_v1_t *this, message_t *message)
+{
+       switch (message->get_exchange_type(message))
+       {
+               case ID_PROT:
+               {       /* add NAT-D payloads to second response, already processed those
+                        * contained in the second request */
+                       if (message->get_payload(message, SECURITY_ASSOCIATION_V1))
+                       {       /* wait for the second exchange */
+                               return NEED_MORE;
+                       }
+                       add_natd_payloads(this, message);
+                       return SUCCESS;
+               }
+               case AGGRESSIVE:
+               {       /* add NAT-D payloads to the first response, process those contained
+                        * in the following second request */
+                       add_natd_payloads(this, message);
+                       return NEED_MORE;
+               }
+               default:
+                       break;
+       }
+       return SUCCESS;
+}
+
+METHOD(task_t, get_type, task_type_t,
+       private_ike_natd_v1_t *this)
+{
+       return TASK_IKE_NATD_V1;
+}
+
+METHOD(task_t, migrate, void,
+       private_ike_natd_v1_t *this, ike_sa_t *ike_sa)
+{
+       this->ike_sa = ike_sa;
+       this->src_seen = FALSE;
+       this->dst_seen = FALSE;
+       this->src_matched = FALSE;
+       this->dst_matched = FALSE;
+}
+
+METHOD(task_t, destroy, void,
+       private_ike_natd_v1_t *this)
+{
+       free(this);
+}
+
+/*
+ * Described in header.
+ */
+ike_natd_v1_t *ike_natd_v1_create(ike_sa_t *ike_sa, bool initiator)
+{
+       private_ike_natd_v1_t *this;
+
+       INIT(this,
+               .public = {
+                       .task = {
+                               .get_type = _get_type,
+                               .migrate = _migrate,
+                               .destroy = _destroy,
+                       },
+               },
+               .ike_sa = ike_sa,
+               .keymat = (keymat_v1_t*)ike_sa->get_keymat(ike_sa),
+               .initiator = initiator,
+       );
+
+       if (initiator)
+       {
+               this->public.task.build = _build_i;
+               this->public.task.process = _process_i;
+       }
+       else
+       {
+               this->public.task.build = _build_r;
+               this->public.task.process = _process_r;
+       }
+
+       return &this->public;
+}
diff --git a/src/libcharon/sa/tasks/ike_natd_v1.h b/src/libcharon/sa/tasks/ike_natd_v1.h
new file mode 100644 (file)
index 0000000..a59054f
--- /dev/null
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2011 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup ike_natd_v1 ike_natd_v1
+ * @{ @ingroup tasks
+ */
+
+#ifndef IKE_NATD_V1_H_
+#define IKE_NATD_V1_H_
+
+typedef struct ike_natd_v1_t ike_natd_v1_t;
+
+#include <library.h>
+#include <sa/ike_sa.h>
+#include <sa/tasks/task.h>
+
+/**
+ * Task of type ike_natd_v1, detects NAT situation in IKEv1 Phase 1.
+ */
+struct ike_natd_v1_t {
+
+       /**
+        * Implements the task_t interface
+        */
+       task_t task;
+};
+
+/**
+ * Create a new ike_natd_v1 task.
+ *
+ * @param ike_sa               IKE_SA this task works for
+ * @param initiator            TRUE if task is the original initiator
+ * @return                             ike_natd_v1 task to handle by the task_manager
+ */
+ike_natd_v1_t *ike_natd_v1_create(ike_sa_t *ike_sa, bool initiator);
+
+#endif /** IKE_NATD_V1_H_ @}*/
index d0eed77..2f12ed5 100644 (file)
@@ -38,6 +38,7 @@ ENUM(task_type_names, TASK_IKE_INIT, TASK_XAUTH_REQUEST,
        "MAIN_MODE",
        "QUICK_MODE",
        "VENDOR_V1",
+       "IKE_NATD_V1",
        "XAUTH_REQUEST",
 );
 #else
@@ -61,6 +62,7 @@ ENUM(task_type_names, TASK_IKE_INIT, TASK_XAUTH_REQUEST,
        "MAIN_MODE",
        "QUICK_MODE",
        "VENDOR_V1",
+       "IKE_NATD_V1",
        "XAUTH_REQUEST",
 );
 #endif /* ME */
index e76ffcd..e4edb78 100644 (file)
@@ -75,6 +75,8 @@ enum task_type_t {
        TASK_QUICK_MODE,
        /** IKEv1 vendor ID payload handling */
        TASK_VENDOR_V1,
+       /** IKEv1 NAT detection */
+       TASK_IKE_NATD_V1,
        /** Request the user/pass with XAUTH */
        TASK_XAUTH_REQUEST,
 };
@@ -122,7 +124,7 @@ struct task_t {
         *
         * @param message               message to read payloads from
         * @return
-        *                                              - FAILED if a critical error occurred
+        *                                              - FAILED if a critical error occurred
         *                                              - DESTROY_ME if IKE_SA has been properly deleted
         *                                              - NEED_MORE if another call to build/process needed
         *                                              - SUCCESS if task completed