1 files changed, 598 insertions, 0 deletions

diff --git a/src/charon/sa/tasks/ike_init.c b/src/charon/sa/tasks/ike_init.c
new file mode 100644
index 000000000..0b493666a
--- /dev/null
+++ b/src/charon/sa/tasks/ike_init.c
@@ -0,0 +1,598 @@
+/**
+ * @file ike_init.c
+ *
+ * @brief Implementation of the ike_init task.
+ *
+ */
+
+/*
+ * Copyright (C) 2005-2007 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 <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;
+	
+	/**
+	 * Connection established by this IKE_SA
+	 */
+	connection_t *connection;
+	
+	/**
+	 * diffie hellman group to use
+	 */
+	diffie_hellman_group_t dh_group;
+	
+	/**
+	 * Diffie hellman object used to generate public DH value.
+	 */
+	diffie_hellman_t *diffie_hellman;
+	
+	/**
+	 * 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;
+	iterator_t *iterator;
+	
+	id = this->ike_sa->get_id(this->ike_sa);
+	
+	this->connection = this->ike_sa->get_connection(this->ike_sa);
+
+	if (this->initiator)
+	{
+		proposal_list = this->connection->get_proposals(this->connection);
+		if (this->old_sa)
+		{	
+			/* include SPI of new IKE_SA when we are rekeying */
+			iterator = proposal_list->create_iterator(proposal_list, TRUE);
+			while (iterator->iterate(iterator, (void**)&proposal))
+			{
+				proposal->set_spi(proposal, id->get_initiator_spi(id));
+			}
+			iterator->destroy(iterator);
+		}
+		
+		sa_payload = sa_payload_create_from_proposal_list(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(this->proposal);
+	}
+	message->add_payload(message, (payload_t*)sa_payload);
+	
+	nonce_payload = nonce_payload_create();
+	nonce_payload->set_nonce(nonce_payload, this->my_nonce);
+	message->add_payload(message, (payload_t*)nonce_payload);
+	
+	ke_payload = ke_payload_create_from_diffie_hellman(this->diffie_hellman);
+	message->add_payload(message, (payload_t*)ke_payload);
+}
+
+/**
+ * Read payloads from message
+ */
+static void process_payloads(private_ike_init_t *this, message_t *message)
+{
+	iterator_t *iterator;
+	payload_t *payload;
+
+	iterator = message->get_payload_iterator(message);
+	while (iterator->iterate(iterator, (void**)&payload))
+	{
+		switch (payload->get_type(payload))
+		{
+			case SECURITY_ASSOCIATION:
+			{
+				sa_payload_t *sa_payload = (sa_payload_t*)payload;
+				linked_list_t *proposal_list;
+	
+				proposal_list = sa_payload->get_proposals(sa_payload);
+				this->proposal = this->connection->select_proposal(
+											  this->connection, proposal_list);
+				proposal_list->destroy_offset(proposal_list, 
+											  offsetof(proposal_t, destroy));
+				break;
+			}
+			case KEY_EXCHANGE:
+			{
+				ke_payload_t *ke_payload = (ke_payload_t*)payload;
+				diffie_hellman_group_t dh_group;
+				chunk_t key_data;
+				
+				dh_group = ke_payload->get_dh_group_number(ke_payload);
+				
+				if (this->initiator)
+				{
+					if (dh_group != this->dh_group)
+					{
+						DBG1(DBG_IKE, "received a DH group not requested (%N)",
+							 diffie_hellman_group_names, dh_group);
+						break;
+					}
+				}
+				else
+				{
+					this->dh_group = dh_group;
+					if (!this->connection->check_dh_group(this->connection, 
+														  dh_group))
+					{
+						break;
+					}
+					this->diffie_hellman = diffie_hellman_create(dh_group);
+				}
+				if (this->diffie_hellman)
+				{
+					key_data = ke_payload->get_key_exchange_data(ke_payload);
+					this->diffie_hellman->set_other_public_value(this->diffie_hellman, key_data);
+				}
+				break;
+			}
+			case NONCE:
+			{
+				nonce_payload_t *nonce_payload = (nonce_payload_t*)payload;
+				this->other_nonce = nonce_payload->get_nonce(nonce_payload);
+				break;
+			}
+			default:
+				break;
+		}
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t build_i(private_ike_init_t *this, message_t *message)
+{
+	randomizer_t *randomizer;
+	status_t status;
+	
+	this->connection = this->ike_sa->get_connection(this->ike_sa);
+	SIG(IKE_UP_START, "initiating IKE_SA to %H",
+		this->connection->get_other_host(this->connection));
+	this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
+	
+	if (this->retry++ >= MAX_RETRIES)
+	{
+		SIG(IKE_UP_FAILED, "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->diffie_hellman)
+	{
+		this->dh_group = this->connection->get_dh_group(this->connection);
+		this->diffie_hellman = diffie_hellman_create(this->dh_group);
+		if (this->diffie_hellman == NULL)
+		{
+			SIG(IKE_UP_FAILED, "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)
+	{
+		randomizer = randomizer_create();
+		status = randomizer->allocate_pseudo_random_bytes(randomizer, NONCE_SIZE,
+														  &this->my_nonce);
+		randomizer->destroy(randomizer);
+		if (status != SUCCESS)
+		{
+			SIG(IKE_UP_FAILED, "error generating random nonce value");
+			return FAILED;
+		}
+	}
+	
+	if (this->cookie.ptr)
+	{
+		message->add_notify(message, FALSE, COOKIE, this->cookie);
+	}
+	
+	build_payloads(this, message);
+	
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t process_r(private_ike_init_t *this, message_t *message)
+{	
+	randomizer_t *randomizer;
+	
+	this->connection = this->ike_sa->get_connection(this->ike_sa);
+	SIG(IKE_UP_FAILED, "%H is initiating an IKE_SA",
+		message->get_source(message));
+	this->ike_sa->set_state(this->ike_sa, IKE_CONNECTING);
+
+	randomizer = randomizer_create();
+	if (randomizer->allocate_pseudo_random_bytes(randomizer, NONCE_SIZE,
+												 &this->my_nonce) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "error generating random nonce value");
+	}
+	randomizer->destroy(randomizer);
+	
+	process_payloads(this, message);
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.build for responder
+ */
+static status_t build_r(private_ike_init_t *this, message_t *message)
+{
+	chunk_t secret;
+	status_t status;
+
+	/* check if we have everything we need */
+	if (this->proposal == NULL ||
+		this->other_nonce.len == 0 || this->my_nonce.len == 0)
+	{
+		SIG(IKE_UP_FAILED, "received proposals inacceptable");
+		message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
+		return FAILED;
+	}
+	
+	if (this->diffie_hellman == NULL ||
+		this->diffie_hellman->get_shared_secret(this->diffie_hellman,
+												&secret) != SUCCESS)
+	{
+		chunk_t chunk;
+		u_int16_t dh_enc;
+		
+		SIG(IKE_UP_FAILED, "received inacceptable DH group (%N)",
+			 diffie_hellman_group_names, this->dh_group);
+		this->dh_group = this->connection->get_dh_group(this->connection);
+		dh_enc = htons(this->dh_group);
+		chunk.ptr = (u_int8_t*)&dh_enc;
+		chunk.len = sizeof(dh_enc);
+		message->add_notify(message, TRUE, INVALID_KE_PAYLOAD, chunk);
+		DBG1(DBG_IKE, "requesting DH group %N",
+			 diffie_hellman_group_names, this->dh_group);
+		return FAILED;
+	}
+
+	
+	if (this->old_sa)
+	{
+		ike_sa_id_t *id;
+		prf_t *prf, *child_prf;
+				
+		/* Apply SPI if we are rekeying */
+		id = this->ike_sa->get_id(this->ike_sa);
+		id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
+	
+		/* setup crypto keys for the rekeyed SA */
+		prf = this->old_sa->get_prf(this->old_sa);
+		child_prf = this->old_sa->get_child_prf(this->old_sa);
+		status = this->ike_sa->derive_keys(this->ike_sa, this->proposal, secret, 
+										   this->other_nonce, this->my_nonce,
+										   FALSE, child_prf, prf);
+	}
+	else
+	{
+		/* setup crypto keys */
+		status =  this->ike_sa->derive_keys(this->ike_sa, this->proposal, secret, 
+										    this->other_nonce, this->my_nonce,
+										    FALSE, NULL, NULL);
+	}
+	if (status != SUCCESS)
+	{
+		SIG(IKE_UP_FAILED, "key derivation failed");
+		message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
+		return FAILED;
+	}
+	
+	build_payloads(this, message);
+
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t process_i(private_ike_init_t *this, message_t *message)
+{
+	chunk_t secret;
+	status_t status;
+	iterator_t *iterator;
+	payload_t *payload;
+
+	/* check for erronous notifies */
+	iterator = message->get_payload_iterator(message);
+	while (iterator->iterate(iterator, (void**)&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 old_dh_group;
+					
+					old_dh_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, old_dh_group,
+						 diffie_hellman_group_names, this->dh_group);
+					if (!this->connection->check_dh_group(this->connection,
+														  this->dh_group))
+					{
+						DBG1(DBG_IKE, "requested DH group %N not acceptable, "
+							"giving up", diffie_hellman_group_names,
+							this->dh_group);
+						iterator->destroy(iterator);
+						return FAILED;
+					}
+					
+					this->ike_sa->reset(this->ike_sa);
+					
+					iterator->destroy(iterator);
+					return NEED_MORE;
+				}
+				case NAT_DETECTION_SOURCE_IP:
+				case NAT_DETECTION_DESTINATION_IP:
+					/* skip, handled in ike_natd_t */
+					break;
+				case COOKIE:
+				{
+					chunk_free(&this->cookie);
+					this->cookie = chunk_clone(notify->get_notification_data(notify));
+					this->ike_sa->reset(this->ike_sa);
+					iterator->destroy(iterator);
+					DBG1(DBG_IKE, "received %N notify", notify_type_names, type);
+					return NEED_MORE;
+				}
+				default:
+				{
+					if (type < 16383)
+					{
+						SIG(IKE_UP_FAILED, "received %N notify error",
+							 notify_type_names, type);
+						iterator->destroy(iterator);
+						return FAILED;	
+					}
+					DBG1(DBG_IKE, "received %N notify",
+						notify_type_names, type);
+					break;
+				}
+			}
+		}
+	}
+	iterator->destroy(iterator);
+	
+	process_payloads(this, message);
+
+	/* check if we have everything */
+	if (this->proposal == NULL ||
+		this->other_nonce.len == 0 || this->my_nonce.len == 0)
+	{
+		SIG(IKE_UP_FAILED, "peers proposal selection invalid");
+		return FAILED;
+	}
+	
+	if (this->diffie_hellman == NULL ||
+		this->diffie_hellman->get_shared_secret(this->diffie_hellman,
+												&secret) != SUCCESS)
+	{
+		SIG(IKE_UP_FAILED, "peers DH group selection invalid");
+		return FAILED;
+	}
+	
+	/* Apply SPI if we are rekeying */
+	if (this->old_sa)
+	{
+		ike_sa_id_t *id;
+		prf_t *prf, *child_prf;
+		
+		id = this->ike_sa->get_id(this->ike_sa);
+		id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
+		
+		/* setup crypto keys for the rekeyed SA */
+		prf = this->old_sa->get_prf(this->old_sa);
+		child_prf = this->old_sa->get_child_prf(this->old_sa);
+		status = this->ike_sa->derive_keys(this->ike_sa, this->proposal, secret, 
+										    this->my_nonce, this->other_nonce,
+										    TRUE, child_prf, prf);
+	}
+	else
+	{
+		/* setup crypto keys for a new SA */
+		status = this->ike_sa->derive_keys(this->ike_sa, this->proposal, secret, 
+										   this->my_nonce, this->other_nonce,
+										   TRUE, NULL, NULL);
+	}
+	if (status != SUCCESS)
+	{
+		SIG(IKE_UP_FAILED, "key derivation failed");
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.get_type
+ */
+static task_type_t get_type(private_ike_init_t *this)
+{
+	return IKE_INIT;
+}
+
+/**
+ * Implementation of task_t.get_type
+ */
+static chunk_t get_lower_nonce(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;
+	}
+}
+
+/**
+ * Implementation of task_t.migrate
+ */
+static void migrate(private_ike_init_t *this, ike_sa_t *ike_sa)
+{
+	DESTROY_IF(this->proposal);
+	DESTROY_IF(this->diffie_hellman);
+	chunk_free(&this->other_nonce);
+	
+	this->ike_sa = ike_sa;
+	this->proposal = NULL;
+	this->diffie_hellman = diffie_hellman_create(this->dh_group);
+}
+
+/**
+ * Implementation of task_t.destroy
+ */
+static void destroy(private_ike_init_t *this)
+{
+	DESTROY_IF(this->proposal);
+	DESTROY_IF(this->diffie_hellman);
+	chunk_free(&this->my_nonce);
+	chunk_free(&this->other_nonce);
+	chunk_free(&this->cookie);
+	free(this);
+}
+
+/*
+ * 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 = malloc_thing(private_ike_init_t);
+
+	this->public.get_lower_nonce = (chunk_t(*)(ike_init_t*))get_lower_nonce;
+	this->public.task.get_type = (task_type_t(*)(task_t*))get_type;
+	this->public.task.migrate = (void(*)(task_t*,ike_sa_t*))migrate;
+	this->public.task.destroy = (void(*)(task_t*))destroy;
+	if (initiator)
+	{
+		this->public.task.build = (status_t(*)(task_t*,message_t*))build_i;
+		this->public.task.process = (status_t(*)(task_t*,message_t*))process_i;
+	}
+	else
+	{
+		this->public.task.build = (status_t(*)(task_t*,message_t*))build_r;
+		this->public.task.process = (status_t(*)(task_t*,message_t*))process_r;
+	}
+	
+	this->ike_sa = ike_sa;
+	this->initiator = initiator;
+	this->dh_group = MODP_NONE;
+	this->diffie_hellman = NULL;
+	this->my_nonce = chunk_empty;
+	this->other_nonce = chunk_empty;
+	this->cookie = chunk_empty;
+	this->proposal = NULL;
+	this->connection = NULL;
+	this->old_sa = old_sa;
+	this->retry = 0;
+	
+	return &this->public;
+}