strongswan/src/charon/sa/ike_sa.h

/**
 * @file ike_sa.h
 *
 * @brief Interface of ike_sa_t.
 *
 */

/*
 * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
 * Copyright (C) 2005 Jan Hutter, Martin Willi
 * 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.
 */

#ifndef IKE_SA_H_
#define IKE_SA_H_

#include <types.h>
#include <encoding/message.h>
#include <encoding/payloads/proposal_substructure.h>
#include <sa/ike_sa_id.h>
#include <sa/child_sa.h>
#include <config/configuration.h>
#include <utils/logger.h>
#include <utils/randomizer.h>
#include <crypto/prfs/prf.h>
#include <crypto/crypters/crypter.h>
#include <crypto/signers/signer.h>
#include <config/connections/connection.h>
#include <config/policies/policy.h>
#include <utils/logger.h>


typedef enum ike_sa_state_t ike_sa_state_t;

/**
 * @brief State of an IKE_SA.
 * 
 * @ingroup sa
 */
enum ike_sa_state_t {
	
	/**
	 * IKE_SA just got created, but is not initiating nor responding yet.
	 */
	SA_CREATED,
	
	/**
	 * IKE_SA gets initiated actively or passively
	 */
	SA_CONNECTING,
	
	/**
	 * IKE_SA is fully established
	 */
	SA_ESTABLISHED,
	
	/**
	 * IKE_SA is in progress of deletion
	 */
	SA_DELETING,
};

/**
 * String mappings for ike_sa_state_t.
 */
extern mapping_t ike_sa_state_m[];


typedef struct ike_sa_t ike_sa_t;

/**
 * @brief Class ike_sa_t representing an IKE_SA.
 *
 * An IKE_SA contains crypto information related to a connection
 * with a peer. It contains multiple IPsec CHILD_SA, for which
 * it is responsible. All traffic is handled by an IKE_SA, using
 * transactions.
 *
 * @b Constructors:
 * - ike_sa_create()
 * 
 * @ingroup sa
 */
struct ike_sa_t {

	/**
	 * @brief Get the id of the SA.
	 * 
	 * Returned ike_sa_id_t object is not getting cloned!
	 *
	 * @param this 			calling object
	 * @return 				ike_sa's ike_sa_id_t
	 */
	ike_sa_id_t* (*get_id) (ike_sa_t *this);
	
	/**
	 * @brief Get the state of the IKE_SA.
	 *
	 * @param this			calling object
	 * @return				state of the IKE_SA
	 */
	ike_sa_state_t (*get_state) (ike_sa_t *this);
	
	/**
	 * @brief Set the state of the IKE_SA.
	 *
	 * @param this			calling object
	 * @param state			state to set for the IKE_SA
	 */
	void (*set_state) (ike_sa_t *this, ike_sa_state_t ike_sa);

	/**
	 * @brief Initiate a new connection.
	 *
	 * The connection_t object is owned by the IKE_SA after the call, so
	 * do not modify or destroy it.
	 * 
	 * @param this 			calling object
	 * @param connection	connection to initiate
	 * @return				
	 * 						- SUCCESS if initialization started
	 * 						- FAILED if in wrong state
	 * 						- DESTROY_ME if initialization failed and IKE_SA MUST be deleted
	 */
	status_t (*initiate) (ike_sa_t *this, connection_t *connection);
	
	/**
	 * @brief Initiates the deletion of an IKE_SA.
	 * 
	 * Sends a delete message to the remote peer and waits for
	 * its response. If the response comes in, or a timeout occurs,
	 * the IKE SA gets deleted.
	 * 
	 * @param this 			calling object
	 * @return
	 * 						- SUCCESS if deletion is initialized
	 * 						- INVALID_STATE, if the IKE_SA is not in 
	 * 						  an established state and can not be
	 * 						  delete (but destroyed).
	 */
	status_t (*delete) (ike_sa_t *this);
	
	/**
	 * @brief Retransmits a request.
	 * 
	 * @param this 			calling object
	 * @param message_id	ID of the request to retransmit
	 * @return
	 * 						- SUCCESS
	 * 						- NOT_FOUND if request doesn't have to be retransmited
	 */
	status_t (*retransmit_request) (ike_sa_t *this, u_int32_t message_id);
	
	/**
	 * @brief Processes a incoming IKEv2-Message.
	 *
	 * Message processing may fail. If a critical failure occurs, 
	 * process_message() return DESTROY_ME. Then the caller must 
	 * destroy the IKE_SA immediatly, as it is unusable.
	 * 
	 * @param this 			calling object
	 * @param[in] message 	message to process
	 * @return 				
	 * 						- SUCCESS
	 * 						- FAILED
	 * 						- DESTROY_ME if this IKE_SA MUST be deleted
	 */
	status_t (*process_message) (ike_sa_t *this,message_t *message);
	
	/**
	 * @brief Check if NAT traversal is enabled for this IKE_SA.
	 *
	 * @param this 			calling object
	 * @return 				TRUE if NAT traversal enabled
	 */
	bool (*is_natt_enabled) (ike_sa_t *this);

	/**
	 * @brief Enable NAT detection for this IKE_SA.
	 *
	 * If a Network address translation is detected with
	 * NAT_DETECTION notifys, a SA must switch to ports
	 * 4500. To enable this behavior, call enable_natt().
	 * It is relevant which peer is NATted, this is specified
	 * with the "local" parameter. Call it twice when both
	 * are NATted.
	 *
	 * @param this 			calling object
	 * @param local			TRUE, if we are NATted, FALSE if other
	 */
	void (*enable_natt) (ike_sa_t *this, bool local);

	/**
	 * @brief Sends a DPD request to the peer.
	 *
	 * To check if a peer is still alive, periodic
	 * empty INFORMATIONAL messages are sent if no
	 * other traffic was received.
	 * 
	 * @param this			calling object
	 * @return
	 * 						- SUCCESS
	 * 						- DESTROY_ME, if peer did not respond
	 */
	status_t (*send_dpd) (ike_sa_t *this);
	
	/**
	 * @brief Sends a keep alive packet.
	 *
	 * To refresh NAT tables in a NAT router
	 * between the peers, periodic empty
	 * UDP packets are sent if no other traffic
	 * was sent.
	 *
	 * @param this				calling object
	 */
	void (*send_keepalive) (ike_sa_t *this);
	
	/**
	 * @brief Log the status of a the ike sa to a logger.
	 *
	 * The status of the IKE SA and all child SAs is logged.
	 * Supplying NULL as logger uses the internal child_sa logger
	 * to do the logging. The log is only done if the supplied
	 * connection name is NULL or matches the connections name.
	 *
	 * @param this 		calling object
	 * @param logger	logger to use for logging
	 * @param name		name of the connection
	 */	
	void (*log_status) (ike_sa_t *this, logger_t *logger, char *name);
		
	/**
	 * @brief Get the internal stored connection_t object.
	 * 
	 * @param this 				calling object
	 * @return					pointer to the internal stored connection_t object
	 */
	connection_t *(*get_connection) (ike_sa_t *this);
	
	/**
	 * @brief Set the internal connection object.
	 * 
	 * @param this 				calling object
	 * @param connection		object of type connection_t
	 */
	void (*set_connection) (ike_sa_t *this, connection_t *connection);
	
	/**
	 * @brief Get the internal stored policy object.
	 * 
	 * @param this 				calling object
	 * @return					pointer to the internal stored policy_t object
	 */
	policy_t *(*get_policy) (ike_sa_t *this);
	
	/**
	 * @brief Set the internal policy_t object.
	 * 
	 * @param this 				calling object
	 * @param policy			object of type policy_t
	 */
	void (*set_policy) (ike_sa_t *this, policy_t *policy);

	/**
	 * @brief Derive all keys and create the transforms for IKE communication.
	 * 
	 * Keys are derived using the diffie hellman secret, nonces and internal
	 * stored SPIs.
	 * Already existing objects get destroyed.
	 * 
	 * @param this 			calling object
	 * @param proposal		proposal which contains algorithms to use
	 * @param dh			diffie hellman object with shared secret
	 * @param nonce_i		initiators nonce
	 * @param nonce_r		responders nonce
	 * @param initiator		role of this IKE SA (TRUE = originial initiator)
	 */
	status_t (*build_transforms) (ike_sa_t *this, proposal_t* proposal,
								  diffie_hellman_t *dh,
								  chunk_t nonce_i, chunk_t nonce_r,
								  bool initiator);
	
	/**
	 * @brief Get the multi purpose prf.
	 * 
	 * @param this 			calling object
	 * @return				pointer to prf_t object
	 */
	prf_t *(*get_prf) (ike_sa_t *this);
	
	/**
	 * @brief Get the prf-object, which is used to derive keys for child SAs.
	 * 
	 * @param this 			calling object
	 * @return				pointer to prf_t object
	 */
	prf_t *(*get_child_prf) (ike_sa_t *this);
	
	/**
	 * @brief Get the prf used for authentication of initiator.
	 * 
	 * @param this 			calling object
	 * @return				pointer to prf_t object
	 */
	prf_t *(*get_prf_auth_i) (ike_sa_t *this);
	
	/**
	 * @brief Get the prf used for authentication of responder.
	 * 
	 * @param this 			calling object
	 * @return				pointer to prf_t object
	 */
	prf_t *(*get_prf_auth_r) (ike_sa_t *this);
	
	/**
	 * @brief Get a CHILD_SA upon request from the other peer.
	 * 
	 * @param this 			calling object
	 * @param spi			spi of the CHILD_SA
	 * @return				child_sa, or NULL if none found
	 */
	child_sa_t* (*get_child_sa) (ike_sa_t *this, u_int32_t spi);

	/**
	 * @brief Close the CHILD SA with the specified reqid.
	 *
	 * Looks for a CHILD SA owned by this IKE_SA, deletes it and
	 * notify's the remote peer about the delete. The associated
	 * states and policies in the kernel get deleted, if they exist.
	 *
	 * @param this 			calling object
	 * @param reqid			reqid of the child SA, as used in the kernel
	 * @return
	 * 						- NOT_FOUND, if IKE_SA has no such CHILD_SA
	 * 						- SUCCESS, if deleted and delete message sent
	 * 
	 * @TODO use spi, not reqid
	 */
	status_t (*delete_child_sa) (ike_sa_t *this, u_int32_t reqid);
	
	/**
	 * @brief Rekey the CHILD SA with the specified reqid.
	 *
	 * Looks for a CHILD SA owned by this IKE_SA, and start the rekeing.
	 *
	 * @param this 			calling object
	 * @param spi			security parameter index identifying the SA to rekey
	 * @return
	 * 						- NOT_FOUND, if IKE_SA has no such CHILD_SA
	 * 						- SUCCESS, if rekeying initiated
	 * 
	 * @TODO use spi, not reqid
	 */
	status_t (*rekey_child_sa) (ike_sa_t *this, u_int32_t reqid);
	
	/**
	 * @brief Associates a child SA to this IKE SA
	 * 
	 * @param this 			calling object
	 * @param child_sa		child_sa to add
	 */
	void (*add_child_sa) (ike_sa_t *this, child_sa_t *child_sa);
	
	/**
	 * @brief Destroys a CHILD_SA upon request from the other peer.
	 * 
	 * @param this 			calling object
	 * @param spi			inbound spi of the CHILD_SA to destroy
	 * @return				outbound spi of the destroyed CHILD_SA
	 */
	u_int32_t (*destroy_child_sa) (ike_sa_t *this, u_int32_t spi);
	
	/**
	 * @brief Destroys a ike_sa_t object.
	 *
	 * @param this 			calling object
	 */
	void (*destroy) (ike_sa_t *this);
};

/**
 * @brief Creates an ike_sa_t object with a specific ID.
 *
 * The ID gets cloned internally.
 *
 * @param[in] ike_sa_id 	ike_sa_id_t object to associate with new IKE_SA
 * @return 					ike_sa_t object
 * 
 * @ingroup sa
 */
ike_sa_t *ike_sa_create(ike_sa_id_t *ike_sa_id);

#endif /*IKE_SA_H_*/