1 files changed, 600 insertions, 0 deletions

diff --git a/src/libcharon/sa/ikev2/tasks/ike_init.c b/src/libcharon/sa/ikev2/tasks/ike_init.c
new file mode 100644
index 000000000..f2a06735e
--- /dev/null
+++ b/src/libcharon/sa/ikev2/tasks/ike_init.c
@@ -0,0 +1,600 @@
+/*
+ * Copyright (C) 2008-2009 Tobias Brunner
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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_init.h"
+
+#include <string.h>
+
+#include <daemon.h>
+#include <sa/ikev2/keymat_v2.h>
+#include <crypto/diffie_hellman.h>
+#include <encoding/payloads/sa_payload.h>
+#include <encoding/payloads/ke_payload.h>
+#include <encoding/payloads/nonce_payload.h>
+
+/** maximum retries to do with cookies/other dh groups */
+#define MAX_RETRIES 5
+
+typedef struct private_ike_init_t private_ike_init_t;
+
+/**
+ * Private members of a ike_init_t task.
+ */
+struct private_ike_init_t {
+
+	/**
+	 * Public methods and task_t interface.
+	 */
+	ike_init_t public;
+
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+
+	/**
+	 * Are we the initiator?
+	 */
+	bool initiator;
+
+	/**
+	 * IKE config to establish
+	 */
+	ike_cfg_t *config;
+
+	/**
+	 * diffie hellman group to use
+	 */
+	diffie_hellman_group_t dh_group;
+
+	/**
+	 * diffie hellman key exchange
+	 */
+	diffie_hellman_t *dh;
+
+	/**
+	 * Keymat derivation (from IKE_SA)
+	 */
+	keymat_v2_t *keymat;
+
+	/**
+	 * nonce chosen by us
+	 */
+	chunk_t my_nonce;
+
+	/**
+	 * nonce chosen by peer
+	 */
+	chunk_t other_nonce;
+
+	/**
+	 * Negotiated proposal used for IKE_SA
+	 */
+	proposal_t *proposal;
+
+	/**
+	 * Old IKE_SA which gets rekeyed
+	 */
+	ike_sa_t *old_sa;
+
+	/**
+	 * cookie received from responder
+	 */
+	chunk_t cookie;
+
+	/**
+	 * retries done so far after failure (cookie or bad dh group)
+	 */
+	u_int retry;
+};
+
+/**
+ * build the payloads for the message
+ */
+static void build_payloads(private_ike_init_t *this, message_t *message)
+{
+	sa_payload_t *sa_payload;
+	ke_payload_t *ke_payload;
+	nonce_payload_t *nonce_payload;
+	linked_list_t *proposal_list;
+	ike_sa_id_t *id;
+	proposal_t *proposal;
+	enumerator_t *enumerator;
+
+	id = this->ike_sa->get_id(this->ike_sa);
+
+	this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
+
+	if (this->initiator)
+	{
+		proposal_list = this->config->get_proposals(this->config);
+		if (this->old_sa)
+		{
+			/* include SPI of new IKE_SA when we are rekeying */
+			enumerator = proposal_list->create_enumerator(proposal_list);
+			while (enumerator->enumerate(enumerator, (void**)&proposal))
+			{
+				proposal->set_spi(proposal, id->get_initiator_spi(id));
+			}
+			enumerator->destroy(enumerator);
+		}
+
+		sa_payload = sa_payload_create_from_proposals_v2(proposal_list);
+		proposal_list->destroy_offset(proposal_list, offsetof(proposal_t, destroy));
+	}
+	else
+	{
+		if (this->old_sa)
+		{
+			/* include SPI of new IKE_SA when we are rekeying */
+			this->proposal->set_spi(this->proposal, id->get_responder_spi(id));
+		}
+		sa_payload = sa_payload_create_from_proposal_v2(this->proposal);
+	}
+	message->add_payload(message, (payload_t*)sa_payload);
+
+	nonce_payload = nonce_payload_create(NONCE);
+	nonce_payload->set_nonce(nonce_payload, this->my_nonce);
+	ke_payload = ke_payload_create_from_diffie_hellman(KEY_EXCHANGE, this->dh);
+
+	if (this->old_sa)
+	{	/* payload order differs if we are rekeying */
+		message->add_payload(message, (payload_t*)nonce_payload);
+		message->add_payload(message, (payload_t*)ke_payload);
+	}
+	else
+	{
+		message->add_payload(message, (payload_t*)ke_payload);
+		message->add_payload(message, (payload_t*)nonce_payload);
+	}
+}
+
+/**
+ * Read payloads from message
+ */
+static void process_payloads(private_ike_init_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	payload_t *payload;
+
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		switch (payload->get_type(payload))
+		{
+			case SECURITY_ASSOCIATION:
+			{
+				sa_payload_t *sa_payload = (sa_payload_t*)payload;
+				linked_list_t *proposal_list;
+				bool private;
+
+				proposal_list = sa_payload->get_proposals(sa_payload);
+				private = this->ike_sa->supports_extension(this->ike_sa,
+														   EXT_STRONGSWAN);
+				this->proposal = this->config->select_proposal(this->config,
+														proposal_list, private);
+				proposal_list->destroy_offset(proposal_list,
+											  offsetof(proposal_t, destroy));
+				break;
+			}
+			case KEY_EXCHANGE:
+			{
+				ke_payload_t *ke_payload = (ke_payload_t*)payload;
+
+				this->dh_group = ke_payload->get_dh_group_number(ke_payload);
+				if (!this->initiator)
+				{
+					this->dh = this->keymat->keymat.create_dh(
+										&this->keymat->keymat, this->dh_group);
+				}
+				if (this->dh)
+				{
+					this->dh->set_other_public_value(this->dh,
+								ke_payload->get_key_exchange_data(ke_payload));
+				}
+				break;
+			}
+			case NONCE:
+			{
+				nonce_payload_t *nonce_payload = (nonce_payload_t*)payload;
+
+				this->other_nonce = nonce_payload->get_nonce(nonce_payload);
+				break;
+			}
+			default:
+				break;
+		}
+	}
+	enumerator->destroy(enumerator);
+}
+
+METHOD(task_t, build_i, status_t,
+	private_ike_init_t *this, message_t *message)
+{
+	this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
+	DBG0(DBG_IKE, "initiating IKE_SA %s[%d] to %H",
+		 this->ike_sa->get_name(this->ike_sa),
+		 this->ike_sa->get_unique_id(this->ike_sa),
+		 this->ike_sa->get_other_host(this->ike_sa));
+	this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
+
+	if (this->retry >= MAX_RETRIES)
+	{
+		DBG1(DBG_IKE, "giving up after %d retries", MAX_RETRIES);
+		return FAILED;
+	}
+
+	/* if the DH group is set via use_dh_group(), we already have a DH object */
+	if (!this->dh)
+	{
+		this->dh_group = this->config->get_dh_group(this->config);
+		this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
+												  this->dh_group);
+		if (!this->dh)
+		{
+			DBG1(DBG_IKE, "configured DH group %N not supported",
+				diffie_hellman_group_names, this->dh_group);
+			return FAILED;
+		}
+	}
+
+	/* generate nonce only when we are trying the first time */
+	if (this->my_nonce.ptr == NULL)
+	{
+		nonce_gen_t *nonceg;
+
+		nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat);
+		if (!nonceg)
+		{
+			DBG1(DBG_IKE, "no nonce generator found to create nonce");
+			return FAILED;
+		}
+		if (!nonceg->allocate_nonce(nonceg, NONCE_SIZE, &this->my_nonce))
+		{
+			DBG1(DBG_IKE, "nonce allocation failed");
+			nonceg->destroy(nonceg);
+			return FAILED;
+		}
+		nonceg->destroy(nonceg);
+	}
+
+	if (this->cookie.ptr)
+	{
+		message->add_notify(message, FALSE, COOKIE, this->cookie);
+	}
+
+	build_payloads(this, message);
+
+#ifdef ME
+	{
+		chunk_t connect_id = this->ike_sa->get_connect_id(this->ike_sa);
+		if (connect_id.ptr)
+		{
+			message->add_notify(message, FALSE, ME_CONNECTID, connect_id);
+		}
+	}
+#endif /* ME */
+
+	return NEED_MORE;
+}
+
+METHOD(task_t, process_r,  status_t,
+	private_ike_init_t *this, message_t *message)
+{
+	nonce_gen_t *nonceg;
+
+	this->config = this->ike_sa->get_ike_cfg(this->ike_sa);
+	DBG0(DBG_IKE, "%H is initiating an IKE_SA", message->get_source(message));
+	this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
+
+	nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat);
+	if (!nonceg)
+	{
+		DBG1(DBG_IKE, "no nonce generator found to create nonce");
+		return FAILED;
+	}
+	if (!nonceg->allocate_nonce(nonceg, NONCE_SIZE, &this->my_nonce))
+	{
+		DBG1(DBG_IKE, "nonce allocation failed");
+		nonceg->destroy(nonceg);
+		return FAILED;
+	}
+	nonceg->destroy(nonceg);
+
+#ifdef ME
+	{
+		notify_payload_t *notify = message->get_notify(message, ME_CONNECTID);
+		if (notify)
+		{
+			chunk_t connect_id = notify->get_notification_data(notify);
+			DBG2(DBG_IKE, "received ME_CONNECTID %#B", &connect_id);
+			charon->connect_manager->stop_checks(charon->connect_manager,
+												 connect_id);
+		}
+	}
+#endif /* ME */
+
+	process_payloads(this, message);
+
+	return NEED_MORE;
+}
+
+/**
+ * Derive the keymat for the IKE_SA
+ */
+static bool derive_keys(private_ike_init_t *this,
+						chunk_t nonce_i, chunk_t nonce_r)
+{
+	keymat_v2_t *old_keymat;
+	pseudo_random_function_t prf_alg = PRF_UNDEFINED;
+	chunk_t skd = chunk_empty;
+	ike_sa_id_t *id;
+
+	id = this->ike_sa->get_id(this->ike_sa);
+	if (this->old_sa)
+	{
+		/* rekeying: Include old SKd, use old PRF, apply SPI */
+		old_keymat = (keymat_v2_t*)this->old_sa->get_keymat(this->old_sa);
+		prf_alg = old_keymat->get_skd(old_keymat, &skd);
+		if (this->initiator)
+		{
+			id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
+		}
+		else
+		{
+			id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
+		}
+	}
+	if (!this->keymat->derive_ike_keys(this->keymat, this->proposal, this->dh,
+									   nonce_i, nonce_r, id, prf_alg, skd))
+	{
+		return FALSE;
+	}
+	charon->bus->ike_keys(charon->bus, this->ike_sa, this->dh, chunk_empty,
+						  nonce_i, nonce_r, this->old_sa, NULL);
+	return TRUE;
+}
+
+METHOD(task_t, build_r, status_t,
+	private_ike_init_t *this, message_t *message)
+{
+	/* check if we have everything we need */
+	if (this->proposal == NULL ||
+		this->other_nonce.len == 0 || this->my_nonce.len == 0)
+	{
+		DBG1(DBG_IKE, "received proposals inacceptable");
+		message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
+		return FAILED;
+	}
+	this->ike_sa->set_proposal(this->ike_sa, this->proposal);
+
+	if (this->dh == NULL ||
+		!this->proposal->has_dh_group(this->proposal, this->dh_group))
+	{
+		u_int16_t group;
+
+		if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
+										  &group, NULL))
+		{
+			DBG1(DBG_IKE, "DH group %N inacceptable, requesting %N",
+				 diffie_hellman_group_names, this->dh_group,
+				 diffie_hellman_group_names, group);
+			this->dh_group = group;
+			group = htons(group);
+			message->add_notify(message, FALSE, INVALID_KE_PAYLOAD,
+								chunk_from_thing(group));
+		}
+		else
+		{
+			DBG1(DBG_IKE, "no acceptable proposal found");
+		}
+		return FAILED;
+	}
+
+	if (!derive_keys(this, this->other_nonce, this->my_nonce))
+	{
+		DBG1(DBG_IKE, "key derivation failed");
+		message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
+		return FAILED;
+	}
+	build_payloads(this, message);
+	return SUCCESS;
+}
+
+METHOD(task_t, process_i, status_t,
+	private_ike_init_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	payload_t *payload;
+
+	/* check for erronous notifies */
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		if (payload->get_type(payload) == NOTIFY)
+		{
+			notify_payload_t *notify = (notify_payload_t*)payload;
+			notify_type_t type = notify->get_notify_type(notify);
+
+			switch (type)
+			{
+				case INVALID_KE_PAYLOAD:
+				{
+					chunk_t data;
+					diffie_hellman_group_t bad_group;
+
+					bad_group = this->dh_group;
+					data = notify->get_notification_data(notify);
+					this->dh_group = ntohs(*((u_int16_t*)data.ptr));
+					DBG1(DBG_IKE, "peer didn't accept DH group %N, "
+						 "it requested %N", diffie_hellman_group_names,
+						 bad_group, diffie_hellman_group_names, this->dh_group);
+
+					if (this->old_sa == NULL)
+					{	/* reset the IKE_SA if we are not rekeying */
+						this->ike_sa->reset(this->ike_sa);
+					}
+
+					enumerator->destroy(enumerator);
+					this->retry++;
+					return NEED_MORE;
+				}
+				case NAT_DETECTION_SOURCE_IP:
+				case NAT_DETECTION_DESTINATION_IP:
+					/* skip, handled in ike_natd_t */
+					break;
+				case MULTIPLE_AUTH_SUPPORTED:
+					/* handled in ike_auth_t */
+					break;
+				case COOKIE:
+				{
+					chunk_free(&this->cookie);
+					this->cookie = chunk_clone(notify->get_notification_data(notify));
+					this->ike_sa->reset(this->ike_sa);
+					enumerator->destroy(enumerator);
+					DBG2(DBG_IKE, "received %N notify", notify_type_names, type);
+					this->retry++;
+					return NEED_MORE;
+				}
+				default:
+				{
+					if (type <= 16383)
+					{
+						DBG1(DBG_IKE, "received %N notify error",
+							 notify_type_names, type);
+						enumerator->destroy(enumerator);
+						return FAILED;
+					}
+					DBG2(DBG_IKE, "received %N notify",
+						notify_type_names, type);
+					break;
+				}
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	process_payloads(this, message);
+
+	/* check if we have everything */
+	if (this->proposal == NULL ||
+		this->other_nonce.len == 0 || this->my_nonce.len == 0)
+	{
+		DBG1(DBG_IKE, "peers proposal selection invalid");
+		return FAILED;
+	}
+	this->ike_sa->set_proposal(this->ike_sa, this->proposal);
+
+	if (this->dh == NULL ||
+		!this->proposal->has_dh_group(this->proposal, this->dh_group))
+	{
+		DBG1(DBG_IKE, "peer DH group selection invalid");
+		return FAILED;
+	}
+
+	if (!derive_keys(this, this->my_nonce, this->other_nonce))
+	{
+		DBG1(DBG_IKE, "key derivation failed");
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+METHOD(task_t, get_type, task_type_t,
+	private_ike_init_t *this)
+{
+	return TASK_IKE_INIT;
+}
+
+METHOD(task_t, migrate, void,
+	private_ike_init_t *this, ike_sa_t *ike_sa)
+{
+	DESTROY_IF(this->proposal);
+	chunk_free(&this->other_nonce);
+
+	this->ike_sa = ike_sa;
+	this->keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa);
+	this->proposal = NULL;
+	if (this->dh && this->dh->get_dh_group(this->dh) != this->dh_group)
+	{	/* reset DH value only if group changed (INVALID_KE_PAYLOAD) */
+		this->dh->destroy(this->dh);
+		this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
+												  this->dh_group);
+	}
+}
+
+METHOD(task_t, destroy, void,
+	private_ike_init_t *this)
+{
+	DESTROY_IF(this->dh);
+	DESTROY_IF(this->proposal);
+	chunk_free(&this->my_nonce);
+	chunk_free(&this->other_nonce);
+	chunk_free(&this->cookie);
+	free(this);
+}
+
+METHOD(ike_init_t, get_lower_nonce, chunk_t,
+	private_ike_init_t *this)
+{
+	if (memcmp(this->my_nonce.ptr, this->other_nonce.ptr,
+			   min(this->my_nonce.len, this->other_nonce.len)) < 0)
+	{
+		return this->my_nonce;
+	}
+	else
+	{
+		return this->other_nonce;
+	}
+}
+
+/*
+ * Described in header.
+ */
+ike_init_t *ike_init_create(ike_sa_t *ike_sa, bool initiator, ike_sa_t *old_sa)
+{
+	private_ike_init_t *this;
+
+	INIT(this,
+		.public = {
+			.task = {
+				.get_type = _get_type,
+				.migrate = _migrate,
+				.destroy = _destroy,
+			},
+			.get_lower_nonce = _get_lower_nonce,
+		},
+		.ike_sa = ike_sa,
+		.initiator = initiator,
+		.dh_group = MODP_NONE,
+		.keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa),
+		.old_sa = old_sa,
+	);
+
+	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;
+}