xref: /openbsd-src/sbin/isakmpd/exchange.h (revision 2f1aa25b0f696ec888d7fe80b22e760eed552d21)

/* $OpenBSD: exchange.h,v 1.37 2018/01/15 09:54:48 mpi Exp $	 */
/* $EOM: exchange.h,v 1.28 2000/09/28 12:54:28 niklas Exp $	 */

/*
 * Copyright (c) 1998, 1999, 2001 Niklas Hallqvist.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This code was written under funding by Ericsson Radio Systems.
 */

#ifndef _EXCHANGE_H_
#define _EXCHANGE_H_

#include <sys/types.h>
#include <sys/queue.h>

#include "exchange_num.h"
#include "isakmp.h"

/* Remove an exchange if it has not been fully negotiated in this time.  */
#define EXCHANGE_MAX_TIME 120

struct crypto_xf;
struct certreq_aca;
struct doi;
struct event;
struct keystate;
struct message;
struct payload;
struct transport;
struct sa;

struct exchange {
	/* Link to exchanges with the same hash value.  */
	LIST_ENTRY(exchange) link;

	/* This exchange is linked to the global exchange list. */
	int		linked;

	/* A name of the SAs this exchange will result in.  XXX non unique?  */
	char           *name;

	/*
	 * A name of the major policy deciding offers and acceptable
	 * proposals.
	 */
	char           *policy;

	/*
	 * A function with a polymorphic argument called after the exchange
	 * has been run to its end, successfully.  The 2nd argument is true
	 * if the finalization hook is called due to the exchange not running
	 * to its end normally.
	 */
	void            (*finalize)(struct exchange *, void *, int);
	void           *finalize_arg;

	/* When several SA's are being negotiated we keep them here.  */
	TAILQ_HEAD(sa_head, sa) sa_list;

	/*
	 * The event that will occur when it has taken too long time to try to
	 * run the exchange and which will trigger auto-destruction.
	 */
	struct event   *death;

	/*
	 * Both initiator and responder cookies.
	 * XXX For code clarity we might split this into two fields.
	 */
	u_int8_t        cookies[ISAKMP_HDR_COOKIES_LEN];

	/* The message ID signifying phase 2 exchanges.  */
	u_int8_t        message_id[ISAKMP_HDR_MESSAGE_ID_LEN];

	/* The exchange type we are using.  */
	u_int8_t        type;

	/* Phase is 1 for ISAKMP SA exchanges, and 2 for application ones.  */
	u_int8_t        phase;

	/* The "step counter" of the exchange, starting from zero.  */
	u_int8_t        step;

	/* 1 if we are the initiator, 0 if we are the responder.  */
	u_int8_t        initiator;

	/* Various flags, look below for descriptions.  */
	u_int32_t       flags;

	/* The DOI that is to handle DOI-specific issues for this exchange.  */
	struct doi     *doi;

	/*
	 * A "program counter" into the script that validate message contents
	 * for this exchange.
	 */
	int16_t        *exch_pc;

	/* The last message received, used for checking for duplicates.  */
	struct message *last_received;

	/* The last message sent, to be acked when something new is received.  */
	struct message *last_sent;

	/*
	 * If some message is queued up for sending, we want to be able to
	 * remove it from the queue, when the exchange is deleted.
	 */
	struct message *in_transit;

	/*
	 * Initiator's & responder's nonces respectively, with lengths.
	 * XXX Should this be in the DOI-specific parts instead?
	 */
	u_int8_t       *nonce_i;
	size_t          nonce_i_len;
	u_int8_t       *nonce_r;
	size_t          nonce_r_len;

	/*
	 * The ID payload contents for the initiator & responder,
	 * respectively.
	 */
	u_int8_t       *id_i;
	size_t          id_i_len;
	u_int8_t       *id_r;
	size_t          id_r_len;

	/* Policy session identifier, where applicable.  */
	int             policy_id;

	/* Crypto info needed to encrypt/decrypt packets in this exchange.  */
	struct crypto_xf *crypto;
	size_t          key_length;
	struct keystate *keystate;

	/*
	 * Used only by KeyNote, to cache the key used to authenticate Phase
	 * 1
	 */
	char           *keynote_key;	/* printable format */

	/*
	 * Received certificate - used to verify signatures on packet,
	 * stored here for later policy processing.
	 *
	 * The rules for the recv_* and sent_* fields are:
	 * - recv_cert stores the credential (if any) received from the peer;
	 *   the kernel may pass us one, but we ignore it. We pass it to the
	 *   kernel so processes can peek at it. When doing passphrase
	 *   authentication in Phase 1, this is empty.
	 * - recv_key stores the key (public or private) used by the peer
	 *   to authenticate. Otherwise, same properties as recv_cert except
	 *   that we don't tell the kernel about passphrases (so we don't
	 *   reveal system-wide passphrases). Processes that used passphrase
	 *   authentication already know the passphrase! We ignore it if/when
	 *   received from the kernel (meaningless).
	 * - sent_cert stores the credential, if any, we used to authenticate
	 *   with the peer. It may be passed to us by the kernel, or we may
	 *   have found it in our certificate storage. In either case, there's
	 *   no point passing it to the kernel, so we don't.
	 * - sent key stores the private key we used for authentication with
	 *   the peer (private key or passphrase). This may have been received
	 *   from the kernel, or may be a system-wide setting. In either case,
	 *   we don't pass it to the kernel, to avoid revealing such information
	 *   to processes (processes either already know it, or have no business
	 *   knowing it).
	 */
	int             recv_certtype, recv_keytype;
	void           *recv_cert;	/* Certificate received from peer,
					 * native format */
	void           *recv_key;	/* Key peer used to authenticate,
					 * native format */

	/* Likewise, for certificates we use. */
	int             sent_certtype, sent_keytype;
	void           *sent_cert;	/* Certificate (to be) sent to peer,
					 * native format */

	/* ACQUIRE sequence number.  */
	u_int32_t       seq;

	/* XXX This is no longer necessary, it is covered by policy.  */

	/* Acceptable authorities for cert requests.  */
	TAILQ_HEAD(aca_head, certreq_aca) aca_list;

	/* DOI-specific opaque data.  */
	void           *data;
};

/* The flag bits.  */
#define EXCHANGE_FLAG_I_COMMITTED	0x0001
#define EXCHANGE_FLAG_HE_COMMITTED	0x0002
#define EXCHANGE_FLAG_COMMITTED		(EXCHANGE_FLAG_I_COMMITTED \
					 | EXCHANGE_FLAG_HE_COMMITTED)
#define EXCHANGE_FLAG_ENCRYPT		0x0004
#define EXCHANGE_FLAG_NAT_T_CAP_PEER	0x0008	/* Peer is NAT capable.  */
#define EXCHANGE_FLAG_NAT_T_ENABLE	0x0010	/* We are doing NAT-T.  */
#define EXCHANGE_FLAG_NAT_T_KEEPALIVE	0x0020	/* We are the NAT:ed peer.  */
#define EXCHANGE_FLAG_DPD_CAP_PEER	0x0040	/* Peer is DPD capable.  */
#define EXCHANGE_FLAG_NAT_T_RFC		0x0080	/* Peer does RFC NAT-T. */
#define EXCHANGE_FLAG_NAT_T_DRAFT	0x0100	/* Peer does draft NAT-T.*/
#define EXCHANGE_FLAG_OPENBSD		0x0200	/* Peer is OpenBSD */

extern int      exchange_add_certs(struct message *);
extern int      exchange_add_certreqs(struct message *);
extern void     exchange_finalize(struct message *);
extern void     exchange_free(struct exchange *);
extern void     exchange_free_aca_list(struct exchange *);
extern void     exchange_establish(char *name, void (*)(struct exchange *,
		    void *, int), void *, int);
extern int	exchange_establish_p1(struct transport *, u_int8_t, u_int32_t,
		    char *, void *, void (*)(struct exchange *, void *, int),
		    void *, int);
extern int      exchange_establish_p2(struct sa *, u_int8_t, char *, void *,
		    void (*)(struct exchange *, void *, int), void *);
extern int      exchange_gen_nonce(struct message *, size_t);
extern void     exchange_init(void);
extern struct exchange *exchange_lookup(u_int8_t *, int);
extern struct exchange *exchange_lookup_by_name(char *, int);
extern struct exchange *exchange_lookup_from_icookie(u_int8_t *);
extern void     exchange_report(void);
extern void     exchange_run(struct message *);
extern int      exchange_save_nonce(struct message *);
extern int      exchange_save_certreq(struct message *);
extern int16_t *exchange_script(struct exchange *);
extern struct exchange *exchange_setup_p1(struct message *, u_int32_t);
extern struct exchange *exchange_setup_p2(struct message *, u_int8_t);
extern void     exchange_upgrade_p1(struct message *);

#endif				/* _EXCHANGE_H_ */