/* $OpenBSD: isakmp_doi.c,v 1.22 2004/06/20 17:17:35 ho Exp $	 */
/* $EOM: isakmp_doi.c,v 1.42 2000/09/12 16:29:41 ho 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.
 */

/*
 * XXX This DOI is very fuzzily defined, and should perhaps be short-circuited
 * to the IPsec DOI instead.  At the moment I will have it as its own DOI,
 * as the ISAKMP architecture seems to imply it should be done like this.
 */

#include <sys/types.h>

#include "sysdep.h"

#include "doi.h"
#include "exchange.h"
#include "isakmp.h"
#include "isakmp_doi.h"
#include "ipsec.h"
#include "log.h"
#include "message.h"
#include "sa.h"
#include "util.h"

#ifdef USE_DEBUG
static int      isakmp_debug_attribute(u_int16_t, u_int8_t *, u_int16_t,
    void *);
#endif
static void     isakmp_finalize_exchange(struct message *);
static struct keystate *isakmp_get_keystate(struct message *);
static int      isakmp_initiator(struct message *);
static int      isakmp_responder(struct message *);
static void     isakmp_setup_situation(u_int8_t *);
static size_t   isakmp_situation_size(void);
static u_int8_t isakmp_spi_size(u_int8_t);
static int	isakmp_validate_attribute(u_int16_t, u_int8_t *, u_int16_t,
    void *);
static int      isakmp_validate_exchange(u_int8_t);
static int	isakmp_validate_id_information(u_int8_t, u_int8_t *,
    u_int8_t *, size_t, struct exchange *);
static int      isakmp_validate_key_information(u_int8_t *, size_t);
static int      isakmp_validate_notification(u_int16_t);
static int      isakmp_validate_proto(u_int8_t);
static int      isakmp_validate_situation(u_int8_t *, size_t *, size_t);
static int      isakmp_validate_transform_id(u_int8_t, u_int8_t);

static struct doi isakmp_doi = {
	{0}, ISAKMP_DOI_ISAKMP, 0, 0, 0,
#ifdef USE_DEBUG
	isakmp_debug_attribute,
#endif
	0,			/* delete_spi not needed.  */
	0,			/* exchange_script not needed.  */
	isakmp_finalize_exchange,
	0,			/* free_exchange_data not needed.  */
	0,			/* free_proto_data not needed.  */
	0,			/* free_sa_data not needed.  */
	isakmp_get_keystate,
	0,			/* get_spi not needed.  */
	0,			/* handle_leftover_payload not needed.  */
	0,			/* informational_post_hook not needed.  */
	0,			/* informational_pre_hook not needed.  */
	0,			/* XXX need maybe be filled-in.  */
	0,			/* proto_init not needed.  */
	isakmp_setup_situation,
	isakmp_situation_size,
	isakmp_spi_size,
	isakmp_validate_attribute,
	isakmp_validate_exchange,
	isakmp_validate_id_information,
	isakmp_validate_key_information,
	isakmp_validate_notification,
	isakmp_validate_proto,
	isakmp_validate_situation,
	isakmp_validate_transform_id,
	isakmp_initiator,
	isakmp_responder,
#ifdef USE_DEBUG
	ipsec_decode_ids
#endif
};

/* Requires doi_init to already have been called.  */
void
isakmp_doi_init(void)
{
	doi_register(&isakmp_doi);
}

#ifdef USE_DEBUG
int
isakmp_debug_attribute(u_int16_t type, u_int8_t *value, u_int16_t len,
    void *vmsg)
{
	/* XXX Not implemented yet.  */
	return 0;
}
#endif				/* USE_DEBUG */

static void
isakmp_finalize_exchange(struct message *msg)
{
}

static struct keystate *
isakmp_get_keystate(struct message *msg)
{
	return 0;
}

static void
isakmp_setup_situation(u_int8_t *buf)
{
	/* Nothing to do.  */
}

static size_t
isakmp_situation_size(void)
{
	return 0;
}

static u_int8_t
isakmp_spi_size(u_int8_t proto)
{
	/* One way to specify ISAKMP SPIs is to say they're zero-sized.  */
	return 0;
}

static int
isakmp_validate_attribute(u_int16_t type, u_int8_t *value, u_int16_t len,
    void *vmsg)
{
	/* XXX Not implemented yet.  */
	return -1;
}

static int
isakmp_validate_exchange(u_int8_t exch)
{
	/* If we get here the exchange is invalid.  */
	return -1;
}

static int
isakmp_validate_id_information(u_int8_t type, u_int8_t *extra, u_int8_t *buf,
    size_t sz, struct exchange *exchange)
{
	return zero_test(extra, ISAKMP_ID_DOI_DATA_LEN);
}

static int
isakmp_validate_key_information(u_int8_t *buf, size_t sz)
{
	/* Nothing to do.  */
	return 0;
}

static int
isakmp_validate_notification(u_int16_t type)
{
	/* If we get here the message type is invalid.  */
	return -1;
}

static int
isakmp_validate_proto(u_int8_t proto)
{
	/* If we get here the protocol is invalid.  */
	return -1;
}

static int
isakmp_validate_situation(u_int8_t *buf, size_t *sz, size_t len)
{
	/* There are no situations in the ISAKMP DOI.  */
	*sz = 0;
	return 0;
}

static int
isakmp_validate_transform_id(u_int8_t proto, u_int8_t transform_id)
{
	/* XXX Not yet implemented.  */
	return -1;
}

static int
isakmp_initiator(struct message *msg)
{
	if (msg->exchange->type != ISAKMP_EXCH_INFO) {
		log_print("isakmp_initiator: unsupported exchange type %d "
		    "in phase %d", msg->exchange->type, msg->exchange->phase);
		return -1;
	}
	return message_send_info(msg);
}

static int
isakmp_responder(struct message *msg)
{
	struct payload *p;

	switch (msg->exchange->type) {
	case ISAKMP_EXCH_INFO:
		for (p = payload_first(msg, ISAKMP_PAYLOAD_NOTIFY); p;
		    p = TAILQ_NEXT(p, link)) {
			LOG_DBG((LOG_EXCHANGE, 10, "isakmp_responder: "
			    "got NOTIFY of type %s, ignoring",
			    constant_name(isakmp_notify_cst,
			    GET_ISAKMP_NOTIFY_MSG_TYPE(p->p))));
			p->flags |= PL_MARK;
		}

		for (p = payload_first(msg, ISAKMP_PAYLOAD_DELETE); p;
		    p = TAILQ_NEXT(p, link)) {
			LOG_DBG((LOG_EXCHANGE, 10,
			    "isakmp_responder: got DELETE, ignoring"));
			p->flags |= PL_MARK;
		}
		return 0;

#ifdef USE_ISAKMP_CFG
	case ISAKMP_EXCH_TRANSACTION:
		/* return 0 isakmp_cfg_responder (msg); */
#endif /* USE_ISAKMP_CFG */

	default:
		/* XXX So far we don't accept any proposals.  */
		if (payload_first(msg, ISAKMP_PAYLOAD_SA)) {
			message_drop(msg, ISAKMP_NOTIFY_NO_PROPOSAL_CHOSEN,
			    0, 1, 0);
			return -1;
		}
	}
	return 0;
}