added keyexchange

1 files changed, 2523 insertions, 0 deletions

diff --git a/keyexchange/isakmpd-20041012/ipsec.c b/keyexchange/isakmpd-20041012/ipsec.c
new file mode 100644
index 0000000..46cb8d9
--- /dev/null
+++ b/keyexchange/isakmpd-20041012/ipsec.c
@@ -0,0 +1,2523 @@
+/* $OpenBSD: ipsec.c,v 1.104 2004/09/17 13:53:08 ho Exp $	 */
+/* $EOM: ipsec.c,v 1.143 2000/12/11 23:57:42 niklas Exp $	 */
+
+/*
+ * Copyright (c) 1998, 1999, 2000, 2001 Niklas Hallqvist.  All rights reserved.
+ * Copyright (c) 2001 Angelos D. Keromytis.  All rights reserved.
+ * Copyright (c) 2001 Håkan Olsson.  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.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sysdep.h"
+
+#include "attribute.h"
+#include "conf.h"
+#include "constants.h"
+#include "crypto.h"
+#include "dh.h"
+#include "doi.h"
+#if defined (USE_DPD)
+#include "dpd.h"
+#endif
+#include "exchange.h"
+#include "hash.h"
+#include "ike_aggressive.h"
+#include "ike_auth.h"
+#include "ike_main_mode.h"
+#include "ike_quick_mode.h"
+#include "ipsec.h"
+#include "ipsec_doi.h"
+#include "isakmp.h"
+#include "isakmp_cfg.h"
+#include "isakmp_fld.h"
+#include "isakmp_num.h"
+#include "log.h"
+#include "math_group.h"
+#include "message.h"
+#if defined (USE_NAT_TRAVERSAL)
+#include "nat_traversal.h"
+#endif
+#include "prf.h"
+#include "sa.h"
+#include "timer.h"
+#include "transport.h"
+#include "util.h"
+#ifdef USE_X509
+#include "x509.h"
+#endif
+
+extern int acquire_only;
+
+/* Backwards compatibility.  */
+#ifndef NI_MAXHOST
+#define NI_MAXHOST 1025
+#endif
+
+/* The replay window size used for all IPsec protocols if not overridden.  */
+#define DEFAULT_REPLAY_WINDOW 16
+
+struct ipsec_decode_arg {
+	struct message *msg;
+	struct sa      *sa;
+	struct proto   *proto;
+};
+
+/* These variables hold the contacted peers ADT state.  */
+struct contact {
+	struct sockaddr *addr;
+	socklen_t       len;
+}              *contacts = 0;
+int             contact_cnt = 0, contact_limit = 0;
+
+static int      addr_cmp(const void *, const void *);
+static int      ipsec_add_contact(struct message *);
+static int      ipsec_contacted(struct message *);
+#ifdef USE_DEBUG
+static int      ipsec_debug_attribute(u_int16_t, u_int8_t *, u_int16_t,
+    void *);
+#endif
+static void     ipsec_delete_spi(struct sa *, struct proto *, int);
+static int16_t *ipsec_exchange_script(u_int8_t);
+static void     ipsec_finalize_exchange(struct message *);
+static void     ipsec_free_exchange_data(void *);
+static void     ipsec_free_proto_data(void *);
+static void     ipsec_free_sa_data(void *);
+static struct keystate *ipsec_get_keystate(struct message *);
+static u_int8_t *ipsec_get_spi(size_t *, u_int8_t, struct message *);
+static int	ipsec_handle_leftover_payload(struct message *, u_int8_t,
+    struct payload *);
+static int      ipsec_informational_post_hook(struct message *);
+static int      ipsec_informational_pre_hook(struct message *);
+static int      ipsec_initiator(struct message *);
+static void     ipsec_proto_init(struct proto *, char *);
+static int      ipsec_responder(struct message *);
+static void     ipsec_setup_situation(u_int8_t *);
+static int      ipsec_set_network(u_int8_t *, u_int8_t *, struct ipsec_sa *);
+static size_t   ipsec_situation_size(void);
+static u_int8_t ipsec_spi_size(u_int8_t);
+static int      ipsec_validate_attribute(u_int16_t, u_int8_t *, u_int16_t,
+    void *);
+static int      ipsec_validate_exchange(u_int8_t);
+static int	ipsec_validate_id_information(u_int8_t, u_int8_t *, u_int8_t *,
+    size_t, struct exchange *);
+static int      ipsec_validate_key_information(u_int8_t *, size_t);
+static int      ipsec_validate_notification(u_int16_t);
+static int      ipsec_validate_proto(u_int8_t);
+static int      ipsec_validate_situation(u_int8_t *, size_t *, size_t);
+static int      ipsec_validate_transform_id(u_int8_t, u_int8_t);
+
+static struct doi ipsec_doi = {
+	{0}, IPSEC_DOI_IPSEC,
+	sizeof(struct ipsec_exch), sizeof(struct ipsec_sa),
+	sizeof(struct ipsec_proto),
+#ifdef USE_DEBUG
+	ipsec_debug_attribute,
+#endif
+	ipsec_delete_spi,
+	ipsec_exchange_script,
+	ipsec_finalize_exchange,
+	ipsec_free_exchange_data,
+	ipsec_free_proto_data,
+	ipsec_free_sa_data,
+	ipsec_get_keystate,
+	ipsec_get_spi,
+	ipsec_handle_leftover_payload,
+	ipsec_informational_post_hook,
+	ipsec_informational_pre_hook,
+	ipsec_is_attribute_incompatible,
+	ipsec_proto_init,
+	ipsec_setup_situation,
+	ipsec_situation_size,
+	ipsec_spi_size,
+	ipsec_validate_attribute,
+	ipsec_validate_exchange,
+	ipsec_validate_id_information,
+	ipsec_validate_key_information,
+	ipsec_validate_notification,
+	ipsec_validate_proto,
+	ipsec_validate_situation,
+	ipsec_validate_transform_id,
+	ipsec_initiator,
+	ipsec_responder,
+	ipsec_decode_ids
+};
+
+int16_t script_quick_mode[] = {
+	ISAKMP_PAYLOAD_HASH,	/* Initiator -> responder.  */
+	ISAKMP_PAYLOAD_SA,
+	ISAKMP_PAYLOAD_NONCE,
+	EXCHANGE_SCRIPT_SWITCH,
+	ISAKMP_PAYLOAD_HASH,	/* Responder -> initiator.  */
+	ISAKMP_PAYLOAD_SA,
+	ISAKMP_PAYLOAD_NONCE,
+	EXCHANGE_SCRIPT_SWITCH,
+	ISAKMP_PAYLOAD_HASH,	/* Initiator -> responder.  */
+	EXCHANGE_SCRIPT_END
+};
+
+int16_t script_new_group_mode[] = {
+	ISAKMP_PAYLOAD_HASH,	/* Initiator -> responder.  */
+	ISAKMP_PAYLOAD_SA,
+	EXCHANGE_SCRIPT_SWITCH,
+	ISAKMP_PAYLOAD_HASH,	/* Responder -> initiator.  */
+	ISAKMP_PAYLOAD_SA,
+	EXCHANGE_SCRIPT_END
+};
+
+struct dst_spi_proto_arg {
+	struct sockaddr *dst;
+	u_int32_t       spi;
+	u_int8_t        proto;
+};
+
+/*
+ * Check if SA matches what we are asking for through V_ARG.  It has to
+ * be a finished phase 2 SA.
+ * if "proto" arg is 0, match any proto
+ */
+static int
+ipsec_sa_check(struct sa *sa, void *v_arg)
+{
+	struct dst_spi_proto_arg *arg = v_arg;
+	struct proto   *proto;
+	struct sockaddr *dst, *src;
+	int             incoming;
+
+	if (sa->phase != 2 || !(sa->flags & SA_FLAG_READY))
+		return 0;
+
+	sa->transport->vtbl->get_dst(sa->transport, &dst);
+	if (memcmp(sockaddr_addrdata(dst), sockaddr_addrdata(arg->dst),
+	    sockaddr_addrlen(dst)) == 0)
+		incoming = 0;
+	else {
+		sa->transport->vtbl->get_src(sa->transport, &src);
+		if (memcmp(sockaddr_addrdata(src), sockaddr_addrdata(arg->dst),
+		    sockaddr_addrlen(src)) == 0)
+			incoming = 1;
+		else
+			return 0;
+	}
+
+	for (proto = TAILQ_FIRST(&sa->protos); proto;
+	    proto = TAILQ_NEXT(proto, link))
+		if ((arg->proto == 0 || proto->proto == arg->proto) &&
+		    memcmp(proto->spi[incoming], &arg->spi, sizeof arg->spi)
+		    == 0)
+			return 1;
+	return 0;
+}
+
+/* Find an SA with a "name" of DST, SPI & PROTO.  */
+struct sa *
+ipsec_sa_lookup(struct sockaddr *dst, u_int32_t spi, u_int8_t proto)
+{
+	struct dst_spi_proto_arg arg;
+
+	arg.dst = dst;
+	arg.spi = spi;
+	arg.proto = proto;
+	return sa_find(ipsec_sa_check, &arg);
+}
+
+/*
+ * Check if SA matches the flow of another SA in V_ARG.  It has to
+ * be a finished non-replaced phase 2 SA.
+ * XXX At some point other selectors will matter here too.
+ */
+static int
+ipsec_sa_check_flow(struct sa *sa, void *v_arg)
+{
+	struct sa      *sa2 = v_arg;
+	struct ipsec_sa *isa = sa->data, *isa2 = sa2->data;
+
+	if (sa == sa2 || sa->phase != 2 ||
+	    (sa->flags & (SA_FLAG_READY | SA_FLAG_REPLACED)) != SA_FLAG_READY)
+		return 0;
+
+	if (isa->tproto != isa2->tproto || isa->sport != isa2->sport ||
+	    isa->dport != isa2->dport)
+		return 0;
+
+	return isa->src_net->sa_family == isa2->src_net->sa_family &&
+	    memcmp(sockaddr_addrdata(isa->src_net),
+	    sockaddr_addrdata(isa2->src_net),
+	    sockaddr_addrlen(isa->src_net)) == 0 &&
+	    memcmp(sockaddr_addrdata(isa->src_mask),
+	    sockaddr_addrdata(isa2->src_mask),
+	    sockaddr_addrlen(isa->src_mask)) == 0 &&
+	    memcmp(sockaddr_addrdata(isa->dst_net),
+	    sockaddr_addrdata(isa2->dst_net),
+	    sockaddr_addrlen(isa->dst_net)) == 0 &&
+	    memcmp(sockaddr_addrdata(isa->dst_mask),
+	    sockaddr_addrdata(isa2->dst_mask),
+	    sockaddr_addrlen(isa->dst_mask)) == 0;
+}
+
+/*
+ * Do IPsec DOI specific finalizations task for the exchange where MSG was
+ * the final message.
+ */
+static void
+ipsec_finalize_exchange(struct message *msg)
+{
+	struct sa      *isakmp_sa = msg->isakmp_sa;
+	struct ipsec_sa *isa;
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	struct sa      *sa = 0, *old_sa;
+	struct proto   *proto, *last_proto = 0;
+#ifdef USE_DEBUG
+	char           *addr1, *addr2, *mask1, *mask2;
+#endif
+
+	switch (exchange->phase) {
+	case 1:
+		switch (exchange->type) {
+		case ISAKMP_EXCH_ID_PROT:
+		case ISAKMP_EXCH_AGGRESSIVE:
+			isa = isakmp_sa->data;
+			isa->hash = ie->hash->type;
+			isa->prf_type = ie->prf_type;
+			isa->skeyid_len = ie->skeyid_len;
+			isa->skeyid_d = ie->skeyid_d;
+			isa->skeyid_a = ie->skeyid_a;
+			/* Prevents early free of SKEYID_*.  */
+			ie->skeyid_a = ie->skeyid_d = 0;
+
+			/*
+			 * If a lifetime was negotiated setup the expiration
+			 * timers.
+			 */
+			if (isakmp_sa->seconds)
+				sa_setup_expirations(isakmp_sa);
+
+#if defined (USE_NAT_TRAVERSAL)
+			if (isakmp_sa->flags & SA_FLAG_NAT_T_KEEPALIVE)
+				nat_t_setup_keepalive(isakmp_sa);
+#endif
+			break;
+		}
+		break;
+
+	case 2:
+		switch (exchange->type) {
+		case IKE_EXCH_QUICK_MODE:
+			/*
+			 * Tell the application(s) about the SPIs and key
+			 * material.
+		         */
+			for (sa = TAILQ_FIRST(&exchange->sa_list); sa;
+			    sa = TAILQ_NEXT(sa, next)) {
+				isa = sa->data;
+
+				if (exchange->initiator) {
+					/*
+					 * Initiator is source, responder is
+					 * destination.
+					 */
+					if (ipsec_set_network(ie->id_ci,
+					    ie->id_cr, isa)) {
+						log_print(
+						    "ipsec_finalize_exchange: "
+						    "ipsec_set_network "
+						    "failed");
+						return;
+					}
+				} else {
+					/*
+					 * Responder is source, initiator is
+					 * destination.
+					 */
+					if (ipsec_set_network(ie->id_cr,
+					    ie->id_ci, isa)) {
+						log_print(
+						    "ipsec_finalize_exchange: "
+						    "ipsec_set_network "
+						    "failed");
+						return;
+					}
+				}
+
+				for (proto = TAILQ_FIRST(&sa->protos),
+				    last_proto = 0; proto;
+				    proto = TAILQ_NEXT(proto, link)) {
+					if (sysdep_ipsec_set_spi(sa, proto,
+					    0, isakmp_sa) ||
+					    (last_proto &&
+					    sysdep_ipsec_group_spis(sa,
+						last_proto, proto, 0)) ||
+					    sysdep_ipsec_set_spi(sa, proto,
+						1, isakmp_sa) ||
+					    (last_proto &&
+						sysdep_ipsec_group_spis(sa,
+						last_proto, proto, 1)))
+						/*
+						 * XXX Tear down this
+						 * exchange.
+						 */
+						return;
+					last_proto = proto;
+				}
+
+#ifdef USE_DEBUG
+				if (sockaddr2text(isa->src_net, &addr1, 0))
+					addr1 = 0;
+				if (sockaddr2text(isa->src_mask, &mask1, 0))
+					mask1 = 0;
+				if (sockaddr2text(isa->dst_net, &addr2, 0))
+					addr2 = 0;
+				if (sockaddr2text(isa->dst_mask, &mask2, 0))
+					mask2 = 0;
+
+				LOG_DBG((LOG_EXCHANGE, 50,
+				    "ipsec_finalize_exchange: src %s %s "
+				    "dst %s %s tproto %u sport %u dport %u",
+				    addr1 ? addr1 : "<??\?>",
+				    mask1 ?  mask1 : "<??\?>",
+				    addr2 ? addr2 : "<??\?>",
+				    mask2 ? mask2 : "<??\?>",
+				    isa->tproto, ntohs(isa->sport),
+				    ntohs(isa->dport)));
+
+				if (addr1)
+					free(addr1);
+				if (mask1)
+					free(mask1);
+				if (addr2)
+					free(addr2);
+				if (mask2)
+					free(mask2);
+
+#endif				/* USE_DEBUG */
+
+				/*
+				 * If this is not an SA acquired by the
+				 * kernel, it needs to have a SPD entry
+				 * (a.k.a. flow) set up.
+			         */
+				if (!(sa->flags & SA_FLAG_ONDEMAND ||
+					conf_get_str("General", "Acquire-Only")
+					|| acquire_only)
+				    && sysdep_ipsec_enable_sa(sa, isakmp_sa))
+					/* XXX Tear down this exchange.  */
+					return;
+
+				/*
+				 * Mark elder SAs with the same flow
+				 * information as replaced.
+				 */
+				while ((old_sa = sa_find(ipsec_sa_check_flow,
+				    sa)) != 0)
+					sa_mark_replaced(old_sa);
+			}
+			break;
+		}
+	}
+}
+
+/* Set the client addresses in ISA from SRC_ID and DST_ID.  */
+static int
+ipsec_set_network(u_int8_t *src_id, u_int8_t *dst_id, struct ipsec_sa *isa)
+{
+	int	id;
+
+	/* Set source address/mask.  */
+	id = GET_ISAKMP_ID_TYPE(src_id);
+	switch (id) {
+	case IPSEC_ID_IPV4_ADDR:
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+		isa->src_net = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in));
+		if (!isa->src_net)
+			goto memfail;
+		isa->src_net->sa_family = AF_INET;
+#ifndef USE_OLD_SOCKADDR
+		isa->src_net->sa_len = sizeof(struct sockaddr_in);
+#endif
+
+		isa->src_mask = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in));
+		if (!isa->src_mask)
+			goto memfail;
+		isa->src_mask->sa_family = AF_INET;
+#ifndef USE_OLD_SOCKADDR
+		isa->src_mask->sa_len = sizeof(struct sockaddr_in);
+#endif
+		break;
+
+	case IPSEC_ID_IPV6_ADDR:
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		isa->src_net = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in6));
+		if (!isa->src_net)
+			goto memfail;
+		isa->src_net->sa_family = AF_INET6;
+#ifndef USE_OLD_SOCKADDR
+		isa->src_net->sa_len = sizeof(struct sockaddr_in6);
+#endif
+
+		isa->src_mask = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in6));
+		if (!isa->src_mask)
+			goto memfail;
+		isa->src_mask->sa_family = AF_INET6;
+#ifndef USE_OLD_SOCKADDR
+		isa->src_mask->sa_len = sizeof(struct sockaddr_in6);
+#endif
+		break;
+
+	case IPSEC_ID_IPV4_RANGE:
+	case IPSEC_ID_IPV6_RANGE:
+	case IPSEC_ID_DER_ASN1_DN:
+	case IPSEC_ID_DER_ASN1_GN:
+	case IPSEC_ID_KEY_ID:
+	default:
+		log_print("ipsec_set_network: ID type %d (%s) not supported",
+		    id, constant_name(ipsec_id_cst, id));
+		return -1;
+	}
+
+	/* Net */
+	memcpy(sockaddr_addrdata(isa->src_net), src_id + ISAKMP_ID_DATA_OFF,
+	    sockaddr_addrlen(isa->src_net));
+
+	/* Mask */
+	switch (id) {
+	case IPSEC_ID_IPV4_ADDR:
+	case IPSEC_ID_IPV6_ADDR:
+		memset(sockaddr_addrdata(isa->src_mask), 0xff,
+		    sockaddr_addrlen(isa->src_mask));
+		break;
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		memcpy(sockaddr_addrdata(isa->src_mask), src_id +
+		    ISAKMP_ID_DATA_OFF + sockaddr_addrlen(isa->src_net),
+		    sockaddr_addrlen(isa->src_mask));
+		break;
+	}
+
+	memcpy(&isa->sport,
+	    src_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF,
+	    IPSEC_ID_PORT_LEN);
+
+	/* Set destination address.  */
+	id = GET_ISAKMP_ID_TYPE(dst_id);
+	switch (id) {
+	case IPSEC_ID_IPV4_ADDR:
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+		isa->dst_net = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in));
+		if (!isa->dst_net)
+			goto memfail;
+		isa->dst_net->sa_family = AF_INET;
+#ifndef USE_OLD_SOCKADDR
+		isa->dst_net->sa_len = sizeof(struct sockaddr_in);
+#endif
+
+		isa->dst_mask = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in));
+		if (!isa->dst_mask)
+			goto memfail;
+		isa->dst_mask->sa_family = AF_INET;
+#ifndef USE_OLD_SOCKADDR
+		isa->dst_mask->sa_len = sizeof(struct sockaddr_in);
+#endif
+		break;
+
+	case IPSEC_ID_IPV6_ADDR:
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		isa->dst_net = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in6));
+		if (!isa->dst_net)
+			goto memfail;
+		isa->dst_net->sa_family = AF_INET6;
+#ifndef USE_OLD_SOCKADDR
+		isa->dst_net->sa_len = sizeof(struct sockaddr_in6);
+#endif
+
+		isa->dst_mask = (struct sockaddr *)calloc(1,
+		    sizeof(struct sockaddr_in6));
+		if (!isa->dst_mask)
+			goto memfail;
+		isa->dst_mask->sa_family = AF_INET6;
+#ifndef USE_OLD_SOCKADDR
+		isa->dst_mask->sa_len = sizeof(struct sockaddr_in6);
+#endif
+		break;
+	}
+
+	/* Net */
+	memcpy(sockaddr_addrdata(isa->dst_net), dst_id + ISAKMP_ID_DATA_OFF,
+	    sockaddr_addrlen(isa->dst_net));
+
+	/* Mask */
+	switch (id) {
+	case IPSEC_ID_IPV4_ADDR:
+	case IPSEC_ID_IPV6_ADDR:
+		memset(sockaddr_addrdata(isa->dst_mask), 0xff,
+		    sockaddr_addrlen(isa->dst_mask));
+		break;
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		memcpy(sockaddr_addrdata(isa->dst_mask), dst_id +
+		    ISAKMP_ID_DATA_OFF + sockaddr_addrlen(isa->dst_net),
+		    sockaddr_addrlen(isa->dst_mask));
+		break;
+	}
+
+	memcpy(&isa->tproto, dst_id + ISAKMP_ID_DOI_DATA_OFF +
+	    IPSEC_ID_PROTO_OFF, IPSEC_ID_PROTO_LEN);
+	memcpy(&isa->dport,
+	    dst_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF,
+	    IPSEC_ID_PORT_LEN);
+	return 0;
+
+memfail:
+	log_error("ipsec_set_network: calloc () failed");
+	return -1;
+}
+
+/* Free the DOI-specific exchange data pointed to by VIE.  */
+static void
+ipsec_free_exchange_data(void *vie)
+{
+	struct ipsec_exch *ie = vie;
+#ifdef USE_ISAKMP_CFG
+	struct isakmp_cfg_attr *attr;
+#endif
+
+	if (ie->sa_i_b)
+		free(ie->sa_i_b);
+	if (ie->id_ci)
+		free(ie->id_ci);
+	if (ie->id_cr)
+		free(ie->id_cr);
+	if (ie->g_xi)
+		free(ie->g_xi);
+	if (ie->g_xr)
+		free(ie->g_xr);
+	if (ie->g_xy)
+		free(ie->g_xy);
+	if (ie->skeyid)
+		free(ie->skeyid);
+	if (ie->skeyid_d)
+		free(ie->skeyid_d);
+	if (ie->skeyid_a)
+		free(ie->skeyid_a);
+	if (ie->skeyid_e)
+		free(ie->skeyid_e);
+	if (ie->hash_i)
+		free(ie->hash_i);
+	if (ie->hash_r)
+		free(ie->hash_r);
+	if (ie->group)
+		group_free(ie->group);
+#ifdef USE_ISAKMP_CFG
+	for (attr = LIST_FIRST(&ie->attrs); attr;
+	    attr = LIST_FIRST(&ie->attrs)) {
+		LIST_REMOVE(attr, link);
+		if (attr->length)
+			free(attr->value);
+		free(attr);
+	}
+#endif
+}
+
+/* Free the DOI-specific SA data pointed to by VISA.  */
+static void
+ipsec_free_sa_data(void *visa)
+{
+	struct ipsec_sa *isa = visa;
+
+	if (isa->src_net)
+		free(isa->src_net);
+	if (isa->src_mask)
+		free(isa->src_mask);
+	if (isa->dst_net)
+		free(isa->dst_net);
+	if (isa->dst_mask)
+		free(isa->dst_mask);
+	if (isa->skeyid_a)
+		free(isa->skeyid_a);
+	if (isa->skeyid_d)
+		free(isa->skeyid_d);
+}
+
+/* Free the DOI-specific protocol data of an SA pointed to by VIPROTO.  */
+static void
+ipsec_free_proto_data(void *viproto)
+{
+	struct ipsec_proto *iproto = viproto;
+	int             i;
+
+	for (i = 0; i < 2; i++)
+		if (iproto->keymat[i])
+			free(iproto->keymat[i]);
+}
+
+/* Return exchange script based on TYPE.  */
+static int16_t *
+ipsec_exchange_script(u_int8_t type)
+{
+	switch (type) {
+#ifdef USE_ISAKMP_CFG
+		case ISAKMP_EXCH_TRANSACTION:
+		return script_transaction;
+#endif
+	case IKE_EXCH_QUICK_MODE:
+		return script_quick_mode;
+	case IKE_EXCH_NEW_GROUP_MODE:
+		return script_new_group_mode;
+	}
+	return 0;
+}
+
+/* Initialize this DOI, requires doi_init to already have been called.  */
+void
+ipsec_init(void)
+{
+	doi_register(&ipsec_doi);
+}
+
+/* Given a message MSG, return a suitable IV (or rather keystate).  */
+static struct keystate *
+ipsec_get_keystate(struct message *msg)
+{
+	struct keystate *ks;
+	struct hash    *hash;
+
+	/* If we have already have an IV, use it.  */
+	if (msg->exchange && msg->exchange->keystate) {
+		ks = malloc(sizeof *ks);
+		if (!ks) {
+			log_error("ipsec_get_keystate: malloc (%lu) failed",
+			    (unsigned long) sizeof *ks);
+			return 0;
+		}
+		memcpy(ks, msg->exchange->keystate, sizeof *ks);
+		return ks;
+	}
+	/*
+	 * For phase 2 when no SA yet is setup we need to hash the IV used by
+	 * the ISAKMP SA concatenated with the message ID, and use that as an
+	 * IV for further cryptographic operations.
+         */
+	if (!msg->isakmp_sa->keystate) {
+		log_print("ipsec_get_keystate: no keystate in ISAKMP SA %p",
+		    msg->isakmp_sa);
+		return 0;
+	}
+	ks = crypto_clone_keystate(msg->isakmp_sa->keystate);
+	if (!ks)
+		return 0;
+
+	hash = hash_get(((struct ipsec_sa *)msg->isakmp_sa->data)->hash);
+	hash->Init(hash->ctx);
+	LOG_DBG_BUF((LOG_CRYPTO, 80, "ipsec_get_keystate: final phase 1 IV",
+	    ks->riv, ks->xf->blocksize));
+	hash->Update(hash->ctx, ks->riv, ks->xf->blocksize);
+	LOG_DBG_BUF((LOG_CRYPTO, 80, "ipsec_get_keystate: message ID",
+	    ((u_int8_t *) msg->iov[0].iov_base) + ISAKMP_HDR_MESSAGE_ID_OFF,
+	    ISAKMP_HDR_MESSAGE_ID_LEN));
+	hash->Update(hash->ctx, ((u_int8_t *) msg->iov[0].iov_base) +
+	    ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN);
+	hash->Final(hash->digest, hash->ctx);
+	crypto_init_iv(ks, hash->digest, ks->xf->blocksize);
+	LOG_DBG_BUF((LOG_CRYPTO, 80, "ipsec_get_keystate: phase 2 IV",
+	    hash->digest, ks->xf->blocksize));
+	return ks;
+}
+
+static void
+ipsec_setup_situation(u_int8_t *buf)
+{
+	SET_IPSEC_SIT_SIT(buf + ISAKMP_SA_SIT_OFF, IPSEC_SIT_IDENTITY_ONLY);
+}
+
+static size_t
+ipsec_situation_size(void)
+{
+	return IPSEC_SIT_SIT_LEN;
+}
+
+static u_int8_t
+ipsec_spi_size(u_int8_t proto)
+{
+	return IPSEC_SPI_SIZE;
+}
+
+static int
+ipsec_validate_attribute(u_int16_t type, u_int8_t * value, u_int16_t len,
+    void *vmsg)
+{
+	struct message *msg = vmsg;
+
+	if ((msg->exchange->phase == 1
+	    && (type < IKE_ATTR_ENCRYPTION_ALGORITHM
+		|| type > IKE_ATTR_GROUP_ORDER))
+	    || (msg->exchange->phase == 2
+		&& (type < IPSEC_ATTR_SA_LIFE_TYPE
+		    || type > IPSEC_ATTR_ECN_TUNNEL)))
+		return -1;
+	return 0;
+}
+
+static int
+ipsec_validate_exchange(u_int8_t exch)
+{
+	return exch != IKE_EXCH_QUICK_MODE && exch != IKE_EXCH_NEW_GROUP_MODE;
+}
+
+static int
+ipsec_validate_id_information(u_int8_t type, u_int8_t *extra, u_int8_t *buf,
+    size_t sz, struct exchange *exchange)
+{
+	u_int8_t        proto = GET_IPSEC_ID_PROTO(extra);
+	u_int16_t       port = GET_IPSEC_ID_PORT(extra);
+
+	LOG_DBG((LOG_MESSAGE, 40,
+	    "ipsec_validate_id_information: proto %d port %d type %d",
+	    proto, port, type));
+	if (type < IPSEC_ID_IPV4_ADDR || type > IPSEC_ID_KEY_ID)
+		return -1;
+
+	switch (type) {
+	case IPSEC_ID_IPV4_ADDR:
+		LOG_DBG_BUF((LOG_MESSAGE, 40,
+		    "ipsec_validate_id_information: IPv4", buf,
+		    sizeof(struct in_addr)));
+		break;
+
+	case IPSEC_ID_IPV6_ADDR:
+		LOG_DBG_BUF((LOG_MESSAGE, 40,
+		    "ipsec_validate_id_information: IPv6", buf,
+		    sizeof(struct in6_addr)));
+		break;
+
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+		LOG_DBG_BUF((LOG_MESSAGE, 40,
+		    "ipsec_validate_id_information: IPv4 network/netmask",
+		    buf, 2 * sizeof(struct in_addr)));
+		break;
+
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		LOG_DBG_BUF((LOG_MESSAGE, 40,
+		    "ipsec_validate_id_information: IPv6 network/netmask",
+		    buf, 2 * sizeof(struct in6_addr)));
+		break;
+
+	default:
+		break;
+	}
+
+	if (exchange->phase == 1
+	    && (proto != IPPROTO_UDP || port != UDP_DEFAULT_PORT)
+	    && (proto != 0 || port != 0)) {
+		/*
+		 * XXX SSH's ISAKMP tester fails this test (proto 17 - port
+		 * 0).
+		 */
+#ifdef notyet
+		return -1;
+#else
+		log_print("ipsec_validate_id_information: dubious ID "
+		    "information accepted");
+#endif
+	}
+	/* XXX More checks?  */
+
+	return 0;
+}
+
+static int
+ipsec_validate_key_information(u_int8_t *buf, size_t sz)
+{
+	/* XXX Not implemented yet.  */
+	return 0;
+}
+
+static int
+ipsec_validate_notification(u_int16_t type)
+{
+	return type < IPSEC_NOTIFY_RESPONDER_LIFETIME
+	    || type > IPSEC_NOTIFY_INITIAL_CONTACT ? -1 : 0;
+}
+
+static int
+ipsec_validate_proto(u_int8_t proto)
+{
+	return proto < IPSEC_PROTO_IPSEC_AH
+	    || proto > IPSEC_PROTO_IPCOMP ? -1 : 0;
+}
+
+static int
+ipsec_validate_situation(u_int8_t *buf, size_t *sz, size_t len)
+{
+	if (len < IPSEC_SIT_SIT_OFF + IPSEC_SIT_SIT_LEN) {
+		log_print("ipsec_validate_situation: payload too short: %u",
+		    (unsigned int) len);
+		return -1;
+	}
+	/* Currently only "identity only" situations are supported.  */
+	if (GET_IPSEC_SIT_SIT(buf) != IPSEC_SIT_IDENTITY_ONLY)
+		return 1;
+
+	*sz = IPSEC_SIT_SIT_LEN;
+
+	return 0;
+}
+
+static int
+ipsec_validate_transform_id(u_int8_t proto, u_int8_t transform_id)
+{
+	switch (proto) {
+		/*
+		 * As no unexpected protocols can occur, we just tie the
+		 * default case to the first case, in orer to silence a GCC
+		 * warning.
+	         */
+		default:
+		case ISAKMP_PROTO_ISAKMP:
+			return transform_id != IPSEC_TRANSFORM_KEY_IKE;
+		case IPSEC_PROTO_IPSEC_AH:
+			return transform_id < IPSEC_AH_MD5
+			    || transform_id > IPSEC_AH_DES ? -1 : 0;
+	case IPSEC_PROTO_IPSEC_ESP:
+		return transform_id < IPSEC_ESP_DES_IV64
+		    || (transform_id > IPSEC_ESP_AES_128_CTR
+			&& transform_id < IPSEC_ESP_AES_MARS)
+		    || transform_id > IPSEC_ESP_AES_TWOFISH ? -1 : 0;
+	case IPSEC_PROTO_IPCOMP:
+		return transform_id < IPSEC_IPCOMP_OUI
+		    || transform_id > IPSEC_IPCOMP_V42BIS ? -1 : 0;
+	}
+}
+
+static int
+ipsec_initiator(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	int             (**script)(struct message *) = 0;
+
+	/* Check that the SA is coherent with the IKE rules.  */
+	if (exchange->type != ISAKMP_EXCH_TRANSACTION
+	    && ((exchange->phase == 1 &&
+		exchange->type != ISAKMP_EXCH_ID_PROT &&
+		exchange->type != ISAKMP_EXCH_AGGRESSIVE &&
+		exchange->type != ISAKMP_EXCH_INFO)
+	    || (exchange->phase == 2 &&	
+		exchange->type != IKE_EXCH_QUICK_MODE &&
+		exchange->type != ISAKMP_EXCH_INFO))) {
+		log_print("ipsec_initiator: unsupported exchange type %d "
+		    "in phase %d", exchange->type, exchange->phase);
+		return -1;
+	}
+	switch (exchange->type) {
+	case ISAKMP_EXCH_ID_PROT:
+		script = ike_main_mode_initiator;
+		break;
+#ifdef USE_AGGRESSIVE
+	case ISAKMP_EXCH_AGGRESSIVE:
+		script = ike_aggressive_initiator;
+		break;
+#endif
+#ifdef USE_ISAKMP_CFG
+	case ISAKMP_EXCH_TRANSACTION:
+		script = isakmp_cfg_initiator;
+		break;
+#endif
+	case ISAKMP_EXCH_INFO:
+		return message_send_info(msg);
+	case IKE_EXCH_QUICK_MODE:
+		script = ike_quick_mode_initiator;
+		break;
+	default:
+		log_print("ipsec_initiator: unsupported exchange type %d",
+			  exchange->type);
+		return -1;
+	}
+
+	/* Run the script code for this step.  */
+	if (script)
+		return script[exchange->step] (msg);
+
+	return 0;
+}
+
+/*
+ * delete all SA's from addr with the associated proto and SPI's
+ *
+ * spis[] is an array of SPIs of size 16-octet for proto ISAKMP
+ * or 4-octet otherwise.
+ */
+static void
+ipsec_delete_spi_list(struct sockaddr *addr, u_int8_t proto, u_int8_t *spis,
+    int nspis, char *type)
+{
+	struct sa      *sa;
+	int             i;
+
+	for (i = 0; i < nspis; i++) {
+		if (proto == ISAKMP_PROTO_ISAKMP) {
+			u_int8_t *spi = spis + i * ISAKMP_HDR_COOKIES_LEN;
+
+			/*
+			 * This really shouldn't happen in IPSEC DOI
+			 * code, but Cisco VPN 3000 sends ISAKMP DELETE's
+			 * this way.
+			 */
+			sa = sa_lookup_isakmp_sa(addr, spi);
+		} else {
+			u_int32_t spi = ((u_int32_t *)spis)[i];
+
+			sa = ipsec_sa_lookup(addr, spi, proto);
+		}
+
+		if (sa == NULL) {
+			LOG_DBG((LOG_SA, 30, "ipsec_delete_spi_list: could "
+			    "not locate SA (SPI %08x, proto %u)",
+			    ((u_int32_t *)spis)[i], proto));
+			continue;
+		}
+		/* Delete the SA and search for the next */
+		LOG_DBG((LOG_SA, 30, "ipsec_delete_spi_list: "
+		    "%s made us delete SA %p (%d references) for proto %d",
+		    type, sa, sa->refcnt, proto));
+
+		sa_free(sa);
+	}
+}
+
+/*
+ * deal with a NOTIFY of INVALID_SPI
+ */
+static void
+ipsec_invalid_spi (struct message *msg, struct payload *p)
+{
+  struct sockaddr *dst;
+  int invspisz, off;
+  u_int32_t spi;
+  u_int16_t totsiz;
+  u_int8_t spisz;
+
+  /* Any notification that make us do something should be protected */
+  if(!TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_HASH]))
+    {
+      LOG_DBG ((LOG_SA, 40,
+      	       "ipsec_invalid_spi: missing HASH payload in INVALID_SPI"
+      	       " notification"));
+      return;
+    }
+
+  /*
+   * get the invalid spi out of the variable sized notification data
+   * field, which is after the variable sized SPI field [which specifies
+   * the receiving entity's phase-1 SPI, not the invalid spi]
+   */
+  totsiz = GET_ISAKMP_GEN_LENGTH (p->p);
+  spisz = GET_ISAKMP_NOTIFY_SPI_SZ (p->p);
+  off = ISAKMP_NOTIFY_SPI_OFF + spisz;
+  invspisz = totsiz - off;
+
+  if (invspisz != sizeof spi)
+    {
+      LOG_DBG ((LOG_SA, 40,
+	       "ipsec_invalid_spi: SPI size %d in INVALID_SPI "
+	       "payload unsupported", spisz));
+       return;
+    }
+  memcpy (&spi, p->p + off, sizeof spi);
+
+  msg->transport->vtbl->get_dst (msg->transport, &dst);
+
+  /* delete matching SPI's from this peer */
+  ipsec_delete_spi_list (dst, 0, (u_int8_t *)&spi, 1, "INVALID_SPI");
+}
+
+static int
+ipsec_responder(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	int             (**script)(struct message *) = 0;
+	struct payload *p;
+	u_int16_t       type;
+
+	/* Check that a new exchange is coherent with the IKE rules.  */
+	if (exchange->step == 0 && exchange->type != ISAKMP_EXCH_TRANSACTION
+	    && ((exchange->phase == 1 &&
+		exchange->type != ISAKMP_EXCH_ID_PROT &&
+		exchange->type != ISAKMP_EXCH_AGGRESSIVE &&
+		exchange->type != ISAKMP_EXCH_INFO)
+	    || (exchange->phase == 2 &&
+		exchange->type != IKE_EXCH_QUICK_MODE &&
+		exchange->type != ISAKMP_EXCH_INFO))) {
+		message_drop(msg, ISAKMP_NOTIFY_UNSUPPORTED_EXCHANGE_TYPE,
+		    0, 1, 0);
+		return -1;
+	}
+	LOG_DBG((LOG_MISC, 30, "ipsec_responder: phase %d exchange %d step %d",
+	    exchange->phase, exchange->type, exchange->step));
+	switch (exchange->type) {
+	case ISAKMP_EXCH_ID_PROT:
+		script = ike_main_mode_responder;
+		break;
+#ifdef USE_AGGRESSIVE
+	case ISAKMP_EXCH_AGGRESSIVE:
+		script = ike_aggressive_responder;
+		break;
+#endif
+#ifdef USE_ISAKMP_CFG
+	case ISAKMP_EXCH_TRANSACTION:
+		script = isakmp_cfg_responder;
+		break;
+#endif
+	case ISAKMP_EXCH_INFO:
+		for (p = payload_first(msg, ISAKMP_PAYLOAD_NOTIFY); p;
+		    p = TAILQ_NEXT(p, link)) {
+			type = GET_ISAKMP_NOTIFY_MSG_TYPE(p->p);
+			LOG_DBG((LOG_EXCHANGE, 10,
+			    "ipsec_responder: got NOTIFY of type %s",
+			    constant_name(isakmp_notify_cst, type)));
+
+			switch (type) {
+			case IPSEC_NOTIFY_INITIAL_CONTACT:
+				/* Handled by leftover logic. */
+				break;
+
+#if defined (USE_DPD)
+			case ISAKMP_NOTIFY_STATUS_DPD_R_U_THERE:
+			case ISAKMP_NOTIFY_STATUS_DPD_R_U_THERE_ACK:
+				dpd_handle_notify(msg, p);
+				break;
+#endif
+
+			default:
+				p->flags |= PL_MARK;
+				break;
+			}
+		}
+
+		/*
+		 * If any DELETEs are in here, let the logic of leftover
+		 * payloads deal with them.
+	         */
+		return 0;
+
+	case IKE_EXCH_QUICK_MODE:
+		script = ike_quick_mode_responder;
+		break;
+
+	default:
+		message_drop(msg, ISAKMP_NOTIFY_UNSUPPORTED_EXCHANGE_TYPE,
+		    0, 1, 0);
+		return -1;
+	}
+
+	/* Run the script code for this step.  */
+	if (script)
+		return script[exchange->step] (msg);
+
+	/*
+	 * XXX So far we don't accept any proposals for exchanges we don't
+	 * support.
+         */
+	if (payload_first(msg, ISAKMP_PAYLOAD_SA)) {
+		message_drop(msg, ISAKMP_NOTIFY_NO_PROPOSAL_CHOSEN, 0, 1, 0);
+		return -1;
+	}
+	return 0;
+}
+
+static enum hashes
+from_ike_hash(u_int16_t hash)
+{
+	switch (hash) {
+		case IKE_HASH_MD5:
+		return HASH_MD5;
+	case IKE_HASH_SHA:
+		return HASH_SHA1;
+	}
+	return -1;
+}
+
+static enum transform
+from_ike_crypto(u_int16_t crypto)
+{
+	/* Coincidentally this is the null operation :-)  */
+	return crypto;
+}
+
+/*
+ * Find out whether the attribute of type TYPE with a LEN length value
+ * pointed to by VALUE is incompatible with what we can handle.
+ * VMSG is a pointer to the current message.
+ */
+int
+ipsec_is_attribute_incompatible(u_int16_t type, u_int8_t *value, u_int16_t len,
+    void *vmsg)
+{
+	struct message *msg = vmsg;
+	u_int16_t dv = decode_16(value);
+
+	if (msg->exchange->phase == 1) {
+		switch (type) {
+		case IKE_ATTR_ENCRYPTION_ALGORITHM:
+			return !crypto_get(from_ike_crypto(dv));
+		case IKE_ATTR_HASH_ALGORITHM:
+			return !hash_get(from_ike_hash(dv));
+		case IKE_ATTR_AUTHENTICATION_METHOD:
+			return !ike_auth_get(dv);
+		case IKE_ATTR_GROUP_DESCRIPTION:
+			return (dv < IKE_GROUP_DESC_MODP_768
+				|| dv > IKE_GROUP_DESC_MODP_1536)
+			    && (dv < IKE_GROUP_DESC_MODP_2048
+				|| dv > IKE_GROUP_DESC_MODP_8192);
+		case IKE_ATTR_GROUP_TYPE:
+			return 1;
+		case IKE_ATTR_GROUP_PRIME:
+			return 1;
+		case IKE_ATTR_GROUP_GENERATOR_1:
+			return 1;
+		case IKE_ATTR_GROUP_GENERATOR_2:
+			return 1;
+		case IKE_ATTR_GROUP_CURVE_A:
+			return 1;
+		case IKE_ATTR_GROUP_CURVE_B:
+			return 1;
+		case IKE_ATTR_LIFE_TYPE:
+			return dv < IKE_DURATION_SECONDS
+			    || dv > IKE_DURATION_KILOBYTES;
+		case IKE_ATTR_LIFE_DURATION:
+			return len != 2 && len != 4;
+		case IKE_ATTR_PRF:
+			return 1;
+		case IKE_ATTR_KEY_LENGTH:
+			/*
+			 * Our crypto routines only allows key-lengths which
+			 * are multiples of an octet.
+		         */
+			return dv % 8 != 0;
+		case IKE_ATTR_FIELD_SIZE:
+			return 1;
+		case IKE_ATTR_GROUP_ORDER:
+			return 1;
+		}
+	} else {
+		switch (type) {
+		case IPSEC_ATTR_SA_LIFE_TYPE:
+			return dv < IPSEC_DURATION_SECONDS
+			    || dv > IPSEC_DURATION_KILOBYTES;
+		case IPSEC_ATTR_SA_LIFE_DURATION:
+			return len != 2 && len != 4;
+		case IPSEC_ATTR_GROUP_DESCRIPTION:
+			return (dv < IKE_GROUP_DESC_MODP_768
+				|| dv > IKE_GROUP_DESC_MODP_1536)
+			    && (dv < IKE_GROUP_DESC_MODP_2048
+				|| IKE_GROUP_DESC_MODP_8192 < dv);
+		case IPSEC_ATTR_ENCAPSULATION_MODE:
+#if defined (USE_NAT_TRAVERSAL)
+			return dv != IPSEC_ENCAP_TUNNEL
+			    && dv != IPSEC_ENCAP_TRANSPORT
+			    && dv != IPSEC_ENCAP_UDP_ENCAP_TUNNEL
+			    && dv != IPSEC_ENCAP_UDP_ENCAP_TRANSPORT
+			    && dv != IPSEC_ENCAP_UDP_ENCAP_TUNNEL_DRAFT
+			    && dv != IPSEC_ENCAP_UDP_ENCAP_TRANSPORT_DRAFT;
+#else
+			return dv < IPSEC_ENCAP_TUNNEL
+			    || dv > IPSEC_ENCAP_TRANSPORT;
+#endif /* USE_NAT_TRAVERSAL */
+		case IPSEC_ATTR_AUTHENTICATION_ALGORITHM:
+			return dv < IPSEC_AUTH_HMAC_MD5
+			    || dv > IPSEC_AUTH_HMAC_RIPEMD;
+		case IPSEC_ATTR_KEY_LENGTH:
+			/*
+			 * XXX Blowfish needs '0'. Others appear to disregard
+			 * this attr?
+			 */
+			return 0;
+		case IPSEC_ATTR_KEY_ROUNDS:
+			return 1;
+		case IPSEC_ATTR_COMPRESS_DICTIONARY_SIZE:
+			return 1;
+		case IPSEC_ATTR_COMPRESS_PRIVATE_ALGORITHM:
+			return 1;
+		case IPSEC_ATTR_ECN_TUNNEL:
+			return 1;
+		}
+	}
+	/* XXX Silence gcc.  */
+	return 1;
+}
+
+#ifdef USE_DEBUG
+/*
+ * Log the attribute of TYPE with a LEN length value pointed to by VALUE
+ * in human-readable form.  VMSG is a pointer to the current message.
+ */
+int
+ipsec_debug_attribute(u_int16_t type, u_int8_t *value, u_int16_t len,
+    void *vmsg)
+{
+	struct message *msg = vmsg;
+	char            val[20];
+
+	/* XXX Transient solution.  */
+	if (len == 2)
+		snprintf(val, sizeof val, "%d", decode_16(value));
+	else if (len == 4)
+		snprintf(val, sizeof val, "%d", decode_32(value));
+	else
+		snprintf(val, sizeof val, "unrepresentable");
+
+	LOG_DBG((LOG_MESSAGE, 50, "Attribute %s value %s",
+	    constant_name(msg->exchange->phase == 1 ? ike_attr_cst :
+	    ipsec_attr_cst, type), val));
+	return 0;
+}
+#endif
+
+/*
+ * Decode the attribute of type TYPE with a LEN length value pointed to by
+ * VALUE.  VIDA is a pointer to a context structure where we can find the
+ * current message, SA and protocol.
+ */
+int
+ipsec_decode_attribute(u_int16_t type, u_int8_t *value, u_int16_t len,
+    void *vida)
+{
+	struct ipsec_decode_arg *ida = vida;
+	struct message *msg = ida->msg;
+	struct sa      *sa = ida->sa;
+	struct ipsec_sa *isa = sa->data;
+	struct proto   *proto = ida->proto;
+	struct ipsec_proto *iproto = proto->data;
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	static int      lifetype = 0;
+
+	if (exchange->phase == 1) {
+		switch (type) {
+		case IKE_ATTR_ENCRYPTION_ALGORITHM:
+			/* XXX Errors possible?  */
+			exchange->crypto = crypto_get(from_ike_crypto(
+			    decode_16(value)));
+			break;
+		case IKE_ATTR_HASH_ALGORITHM:
+			/* XXX Errors possible?  */
+			ie->hash = hash_get(from_ike_hash(decode_16(value)));
+			break;
+		case IKE_ATTR_AUTHENTICATION_METHOD:
+			/* XXX Errors possible?  */
+			ie->ike_auth = ike_auth_get(decode_16(value));
+			break;
+		case IKE_ATTR_GROUP_DESCRIPTION:
+			isa->group_desc = decode_16(value);
+			break;
+		case IKE_ATTR_GROUP_TYPE:
+			break;
+		case IKE_ATTR_GROUP_PRIME:
+			break;
+		case IKE_ATTR_GROUP_GENERATOR_1:
+			break;
+		case IKE_ATTR_GROUP_GENERATOR_2:
+			break;
+		case IKE_ATTR_GROUP_CURVE_A:
+			break;
+		case IKE_ATTR_GROUP_CURVE_B:
+			break;
+		case IKE_ATTR_LIFE_TYPE:
+			lifetype = decode_16(value);
+			return 0;
+		case IKE_ATTR_LIFE_DURATION:
+			switch (lifetype) {
+			case IKE_DURATION_SECONDS:
+				switch (len) {
+				case 2:
+					sa->seconds = decode_16(value);
+					break;
+				case 4:
+					sa->seconds = decode_32(value);
+					break;
+				default:
+					log_print("ipsec_decode_attribute: "
+					    "unreasonable lifetime");
+				}
+				break;
+			case IKE_DURATION_KILOBYTES:
+				switch (len) {
+				case 2:
+					sa->kilobytes = decode_16(value);
+					break;
+				case 4:
+					sa->kilobytes = decode_32(value);
+					break;
+				default:
+					log_print("ipsec_decode_attribute: "
+					    "unreasonable lifetime");
+				}
+				break;
+			default:
+				log_print("ipsec_decode_attribute: unknown "
+				    "lifetime type");
+			}
+			break;
+		case IKE_ATTR_PRF:
+			break;
+		case IKE_ATTR_KEY_LENGTH:
+			exchange->key_length = decode_16(value) / 8;
+			break;
+		case IKE_ATTR_FIELD_SIZE:
+			break;
+		case IKE_ATTR_GROUP_ORDER:
+			break;
+		}
+	} else {
+		switch (type) {
+		case IPSEC_ATTR_SA_LIFE_TYPE:
+			lifetype = decode_16(value);
+			return 0;
+		case IPSEC_ATTR_SA_LIFE_DURATION:
+			switch (lifetype) {
+			case IPSEC_DURATION_SECONDS:
+				switch (len) {
+				case 2:
+					sa->seconds = decode_16(value);
+					break;
+				case 4:
+					sa->seconds = decode_32(value);
+					break;
+				default:
+					log_print("ipsec_decode_attribute: "
+					    "unreasonable lifetime");
+				}
+				break;
+			case IPSEC_DURATION_KILOBYTES:
+				switch (len) {
+				case 2:
+					sa->kilobytes = decode_16(value);
+					break;
+				case 4:
+					sa->kilobytes = decode_32(value);
+					break;
+				default:
+					log_print("ipsec_decode_attribute: "
+					    "unreasonable lifetime");
+				}
+				break;
+			default:
+				log_print("ipsec_decode_attribute: unknown "
+				    "lifetime type");
+			}
+			break;
+		case IPSEC_ATTR_GROUP_DESCRIPTION:
+			isa->group_desc = decode_16(value);
+			break;
+		case IPSEC_ATTR_ENCAPSULATION_MODE:
+			/*
+			 * XXX Multiple protocols must have same
+			 * encapsulation mode, no?
+			 */
+			iproto->encap_mode = decode_16(value);
+			break;
+		case IPSEC_ATTR_AUTHENTICATION_ALGORITHM:
+			iproto->auth = decode_16(value);
+			break;
+		case IPSEC_ATTR_KEY_LENGTH:
+			iproto->keylen = decode_16(value);
+			break;
+		case IPSEC_ATTR_KEY_ROUNDS:
+			iproto->keyrounds = decode_16(value);
+			break;
+		case IPSEC_ATTR_COMPRESS_DICTIONARY_SIZE:
+			break;
+		case IPSEC_ATTR_COMPRESS_PRIVATE_ALGORITHM:
+			break;
+		case IPSEC_ATTR_ECN_TUNNEL:
+			break;
+		}
+	}
+	lifetype = 0;
+	return 0;
+}
+
+/*
+ * Walk over the attributes of the transform payload found in BUF, and
+ * fill out the fields of the SA attached to MSG.  Also mark the SA as
+ * processed.
+ */
+void
+ipsec_decode_transform(struct message *msg, struct sa *sa, struct proto *proto,
+    u_int8_t *buf)
+{
+	struct ipsec_exch *ie = msg->exchange->data;
+	struct ipsec_decode_arg ida;
+
+	LOG_DBG((LOG_MISC, 20, "ipsec_decode_transform: transform %d chosen",
+	    GET_ISAKMP_TRANSFORM_NO(buf)));
+
+	ida.msg = msg;
+	ida.sa = sa;
+	ida.proto = proto;
+
+	/* The default IKE lifetime is 8 hours.  */
+	if (sa->phase == 1)
+		sa->seconds = 28800;
+
+	/* Extract the attributes and stuff them into the SA.  */
+	attribute_map(buf + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+	    GET_ISAKMP_GEN_LENGTH(buf) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+	    ipsec_decode_attribute, &ida);
+
+	/*
+	 * If no pseudo-random function was negotiated, it's HMAC.
+	 * XXX As PRF_HMAC currently is zero, this is a no-op.
+         */
+	if (!ie->prf_type)
+		ie->prf_type = PRF_HMAC;
+}
+
+/*
+ * Delete the IPsec SA represented by the INCOMING direction in protocol PROTO
+ * of the IKE security association SA.
+ */
+static void
+ipsec_delete_spi(struct sa *sa, struct proto *proto, int incoming)
+{
+	if (sa->phase == 1)
+		return;
+	/* XXX Error handling?  Is it interesting?  */
+	sysdep_ipsec_delete_spi(sa, proto, incoming);
+}
+
+/*
+ * Store BUF into the g^x entry of the exchange that message MSG belongs to.
+ * PEER is non-zero when the value is our peer's, and zero when it is ours.
+ */
+static int
+ipsec_g_x(struct message *msg, int peer, u_int8_t *buf)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	u_int8_t      **g_x;
+	int             initiator = exchange->initiator ^ peer;
+	char            header[32];
+
+	g_x = initiator ? &ie->g_xi : &ie->g_xr;
+	*g_x = malloc(ie->g_x_len);
+	if (!*g_x) {
+		log_error("ipsec_g_x: malloc (%lu) failed",
+		    (unsigned long)ie->g_x_len);
+		return -1;
+	}
+	memcpy(*g_x, buf, ie->g_x_len);
+	snprintf(header, sizeof header, "ipsec_g_x: g^x%c",
+	    initiator ? 'i' : 'r');
+	LOG_DBG_BUF((LOG_MISC, 80, header, *g_x, ie->g_x_len));
+	return 0;
+}
+
+/* Generate our DH value.  */
+int
+ipsec_gen_g_x(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	u_int8_t       *buf;
+
+	buf = malloc(ISAKMP_KE_SZ + ie->g_x_len);
+	if (!buf) {
+		log_error("ipsec_gen_g_x: malloc (%lu) failed",
+		    ISAKMP_KE_SZ + (unsigned long)ie->g_x_len);
+		return -1;
+	}
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_KEY_EXCH, buf,
+	    ISAKMP_KE_SZ + ie->g_x_len, 1)) {
+		free(buf);
+		return -1;
+	}
+	if (dh_create_exchange(ie->group, buf + ISAKMP_KE_DATA_OFF)) {
+		log_print("ipsec_gen_g_x: dh_create_exchange failed");
+		free(buf);
+		return -1;
+	}
+	return ipsec_g_x(msg, 0, buf + ISAKMP_KE_DATA_OFF);
+}
+
+/* Save the peer's DH value.  */
+int
+ipsec_save_g_x(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	struct payload *kep;
+
+	kep = payload_first(msg, ISAKMP_PAYLOAD_KEY_EXCH);
+	kep->flags |= PL_MARK;
+	ie->g_x_len = GET_ISAKMP_GEN_LENGTH(kep->p) - ISAKMP_KE_DATA_OFF;
+
+	/* Check that the given length matches the group's expectancy.  */
+	if (ie->g_x_len != (size_t) dh_getlen(ie->group)) {
+		/* XXX Is this a good notify type?  */
+		message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
+		return -1;
+	}
+	return ipsec_g_x(msg, 1, kep->p + ISAKMP_KE_DATA_OFF);
+}
+
+/*
+ * Get a SPI for PROTO and the transport MSG passed over.  Store the
+ * size where SZ points.  NB!  A zero return is OK if *SZ is zero.
+ */
+static u_int8_t *
+ipsec_get_spi(size_t *sz, u_int8_t proto, struct message *msg)
+{
+	struct sockaddr *dst, *src;
+	struct transport *transport = msg->transport;
+
+	if (msg->exchange->phase == 1) {
+		*sz = 0;
+		return 0;
+	} else {
+		/* We are the destination in the SA we want a SPI for.  */
+		transport->vtbl->get_src(transport, &dst);
+		/* The peer is the source.  */
+		transport->vtbl->get_dst(transport, &src);
+		return sysdep_ipsec_get_spi(sz, proto, src, dst,
+		    msg->exchange->seq);
+	}
+}
+
+/*
+ * We have gotten a payload PAYLOAD of type TYPE, which did not get handled
+ * by the logic of the exchange MSG takes part in.  Now is the time to deal
+ * with such a payload if we know how to, if we don't, return -1, otherwise
+ * 0.
+ */
+int
+ipsec_handle_leftover_payload(struct message *msg, u_int8_t type,
+    struct payload *payload)
+{
+	u_int32_t       spisz, nspis;
+	struct sockaddr *dst;
+	int             reenter = 0;
+	u_int8_t       *spis, proto;
+	struct sa      *sa;
+
+	switch (type) {
+	case ISAKMP_PAYLOAD_DELETE:
+		proto = GET_ISAKMP_DELETE_PROTO(payload->p);
+		nspis = GET_ISAKMP_DELETE_NSPIS(payload->p);
+		spisz = GET_ISAKMP_DELETE_SPI_SZ(payload->p);
+
+		if (nspis == 0) {
+			LOG_DBG((LOG_SA, 60, "ipsec_handle_leftover_payload: "
+			    "message specified zero SPIs, ignoring"));
+			return -1;
+		}
+		/* verify proper SPI size */
+		if ((proto == ISAKMP_PROTO_ISAKMP && spisz !=
+			ISAKMP_HDR_COOKIES_LEN)
+		    || (proto != ISAKMP_PROTO_ISAKMP && spisz !=
+			sizeof(u_int32_t))) {
+			log_print("ipsec_handle_leftover_payload: invalid SPI "
+			    "size %d for proto %d in DELETE payload",
+			    spisz, proto);
+			return -1;
+		}
+		spis = (u_int8_t *) malloc(nspis * spisz);
+		if (!spis) {
+			log_error("ipsec_handle_leftover_payload: malloc "
+			    "(%d) failed", nspis * spisz);
+			return -1;
+		}
+		/* extract SPI and get dst address */
+		memcpy(spis, payload->p + ISAKMP_DELETE_SPI_OFF, nspis * spisz);
+		msg->transport->vtbl->get_dst(msg->transport, &dst);
+
+		ipsec_delete_spi_list(dst, proto, spis, nspis, "DELETE");
+
+		free(spis);
+		payload->flags |= PL_MARK;
+		return 0;
+
+	case ISAKMP_PAYLOAD_NOTIFY:
+		switch (GET_ISAKMP_NOTIFY_MSG_TYPE(payload->p)) {
+		case IPSEC_NOTIFY_INITIAL_CONTACT:
+			/*
+			 * Permit INITIAL-CONTACT if
+			 *   - this is not an AGGRESSIVE mode exchange
+			 *   - it is protected by an ISAKMP SA
+		         *
+			 * XXX Instead of the first condition above, we could
+			 * XXX permit this only for phase 2. In the last
+			 * XXX packet of main-mode, this payload, while
+			 * XXX encrypted, is not part of the hash digest.  As
+			 * XXX we currently send our own INITIAL-CONTACTs at
+			 * XXX this point, this too would need to be changed.
+		         */
+			if (msg->exchange->type == ISAKMP_EXCH_AGGRESSIVE) {
+				log_print("ipsec_handle_leftover_payload: got "
+				    "INITIAL-CONTACT in AGGRESSIVE mode");
+				return -1;
+			}
+			if ((msg->exchange->flags & EXCHANGE_FLAG_ENCRYPT)
+			    == 0) {
+				log_print("ipsec_handle_leftover_payload: got "
+				    "INITIAL-CONTACT without ISAKMP SA");
+				return -1;
+			}
+
+			if ((msg->flags & MSG_AUTHENTICATED) == 0) {
+				log_print("ipsec_handle_leftover_payload: "
+				    "got unauthenticated INITIAL-CONTACT");
+				return -1;
+			}
+			/*
+			 * Find out who is sending this and then delete every
+			 * SA that is ready.  Exchanges will timeout
+			 * themselves and then the non-ready SAs will
+			 * disappear too.
+		         */
+			msg->transport->vtbl->get_dst(msg->transport, &dst);
+			while ((sa = sa_lookup_by_peer(dst,
+			    sysdep_sa_len(dst))) != 0) {
+				/*
+				 * Don't delete the current SA -- we received
+				 * the notification over it, so it's obviously
+				 * still active. We temporarily need to remove
+				 * the SA from the list to avoid an endless
+				 * loop, but keep a reference so it won't
+				 * disappear meanwhile.
+			         */
+				if (sa == msg->isakmp_sa) {
+					sa_reference(sa);
+					sa_remove(sa);
+					reenter = 1;
+					continue;
+				}
+				LOG_DBG((LOG_SA, 30,
+				    "ipsec_handle_leftover_payload: "
+				    "INITIAL-CONTACT made us delete SA %p",
+				    sa));
+				sa_delete(sa, 0);
+			}
+
+			if (reenter) {
+				sa_enter(msg->isakmp_sa);
+				sa_release(msg->isakmp_sa);
+			}
+			payload->flags |= PL_MARK;
+			return 0;
+		}
+	}
+	return -1;
+}
+
+/* Return the encryption keylength in octets of the ESP protocol PROTO.  */
+int
+ipsec_esp_enckeylength(struct proto *proto)
+{
+	struct ipsec_proto *iproto = proto->data;
+
+	/* Compute the keylength to use.  */
+	switch (proto->id) {
+	case IPSEC_ESP_DES:
+	case IPSEC_ESP_DES_IV32:
+	case IPSEC_ESP_DES_IV64:
+		return 8;
+	case IPSEC_ESP_3DES:
+		return 24;
+	case IPSEC_ESP_CAST:
+		if (!iproto->keylen)
+			return 16;
+		return iproto->keylen / 8;
+	case IPSEC_ESP_AES:
+	case IPSEC_ESP_AES_128_CTR:
+		if (!iproto->keylen)
+			return 16;
+		/* Fallthrough */
+	default:
+		return iproto->keylen / 8;
+	}
+}
+
+/* Return the authentication keylength in octets of the ESP protocol PROTO.  */
+int
+ipsec_esp_authkeylength(struct proto *proto)
+{
+	struct ipsec_proto *iproto = proto->data;
+
+	switch (iproto->auth) {
+	case IPSEC_AUTH_HMAC_MD5:
+		return 16;
+	case IPSEC_AUTH_HMAC_SHA:
+	case IPSEC_AUTH_HMAC_RIPEMD:
+		return 20;
+	case IPSEC_AUTH_HMAC_SHA2_256:
+		return 32;
+	case IPSEC_AUTH_HMAC_SHA2_384:
+		return 48;
+	case IPSEC_AUTH_HMAC_SHA2_512:
+		return 64;
+	default:
+		return 0;
+	}
+}
+
+/* Return the authentication keylength in octets of the AH protocol PROTO.  */
+int
+ipsec_ah_keylength(struct proto *proto)
+{
+	switch (proto->id) {
+		case IPSEC_AH_MD5:
+		return 16;
+	case IPSEC_AH_SHA:
+	case IPSEC_AH_RIPEMD:
+		return 20;
+	case IPSEC_AH_SHA2_256:
+		return 32;
+	case IPSEC_AH_SHA2_384:
+		return 48;
+	case IPSEC_AH_SHA2_512:
+		return 64;
+	default:
+		return -1;
+	}
+}
+
+/* Return the total keymaterial length of the protocol PROTO.  */
+int
+ipsec_keymat_length(struct proto *proto)
+{
+	switch (proto->proto) {
+		case IPSEC_PROTO_IPSEC_ESP:
+		return ipsec_esp_enckeylength(proto)
+		    + ipsec_esp_authkeylength(proto);
+	case IPSEC_PROTO_IPSEC_AH:
+		return ipsec_ah_keylength(proto);
+	default:
+		return -1;
+	}
+}
+
+/* Helper function for ipsec_get_id().  */
+static int
+ipsec_get_proto_port(char *section, u_int8_t *tproto, u_int16_t *port)
+{
+	struct protoent	*pe = NULL;
+	struct servent	*se;
+	char	*pstr;
+
+	pstr = conf_get_str(section, "Protocol");
+	if (!pstr) {
+		*tproto = 0;
+		return 0;
+	}
+	*tproto = (u_int8_t)atoi(pstr);
+	if (!*tproto) {
+		pe = getprotobyname(pstr);
+		if (pe)
+			*tproto = pe->p_proto;
+	}
+	if (!*tproto) {
+		log_print("ipsec_get_proto_port: protocol \"%s\" unknown",
+		    pstr);
+		return -1;
+	}
+
+	pstr = conf_get_str(section, "Port");
+	if (!pstr)
+		return 0;
+	*port = (u_int16_t)atoi(pstr);
+	if (!*port) {
+		se = getservbyname(pstr,
+		    pe ? pe->p_name : (pstr ? pstr : NULL));
+		if (se)
+			*port = se->s_port;
+	}
+	if (!*port) {
+		log_print("ipsec_get_proto_port: port \"%s\" unknown",
+		    pstr);
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ * Out of a named section SECTION in the configuration file find out
+ * the network address and mask as well as the ID type.  Put the info
+ * in the areas pointed to by ADDR, MASK, TPROTO, PORT, and ID respectively.
+ * Return 0 on success and -1 on failure.
+ */
+int
+ipsec_get_id(char *section, int *id, struct sockaddr **addr,
+    struct sockaddr **mask, u_int8_t *tproto, u_int16_t *port)
+{
+    char	*type, *address, *netmask;
+
+	type = conf_get_str(section, "ID-type");
+	if (!type) {
+		log_print("ipsec_get_id: section %s has no \"ID-type\" tag",
+		    section);
+		return -1;
+	}
+	*id = constant_value(ipsec_id_cst, type);
+	switch (*id) {
+	case IPSEC_ID_IPV4_ADDR:
+	case IPSEC_ID_IPV6_ADDR: {
+		int ret;
+
+		address = conf_get_str(section, "Address");
+		if (!address) {
+			log_print("ipsec_get_id: section %s has no "
+			    "\"Address\" tag", section);
+			return -1;
+		}
+		if (text2sockaddr(address, NULL, addr)) {
+			log_print("ipsec_get_id: invalid address %s in "
+			    "section %s", address, section);
+			return -1;
+		}
+		ret = ipsec_get_proto_port(section, tproto, port);
+		if (ret < 0)
+			free(*addr);
+
+		return ret;
+	}
+
+#ifdef notyet
+	case IPSEC_ID_FQDN:
+		return -1;
+
+	case IPSEC_ID_USER_FQDN:
+		return -1;
+#endif
+
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+	case IPSEC_ID_IPV6_ADDR_SUBNET: {
+		int ret;
+
+		address = conf_get_str(section, "Network");
+		if (!address) {
+			log_print("ipsec_get_id: section %s has no "
+			    "\"Network\" tag", section);
+			return -1;
+		}
+		if (text2sockaddr(address, NULL, addr)) {
+			log_print("ipsec_get_id: invalid section %s "
+			    "network %s", section, address);
+			return -1;
+		}
+		netmask = conf_get_str(section, "Netmask");
+		if (!netmask) {
+			log_print("ipsec_get_id: section %s has no "
+			    "\"Netmask\" tag", section);
+			free(*addr);
+			return -1;
+		}
+		if (text2sockaddr(netmask, NULL, mask)) {
+			log_print("ipsec_id_build: invalid section %s "
+			    "network %s", section, netmask);
+			free(*addr);
+			return -1;
+		}
+		ret = ipsec_get_proto_port(section, tproto, port);
+		if (ret < 0) {
+			free(*mask);
+			free(*addr);
+		}
+		return ret;
+	}
+
+#ifdef notyet
+	case IPSEC_ID_IPV4_RANGE:
+		return -1;
+
+	case IPSEC_ID_IPV6_RANGE:
+		return -1;
+
+	case IPSEC_ID_DER_ASN1_DN:
+		return -1;
+
+	case IPSEC_ID_DER_ASN1_GN:
+		return -1;
+
+	case IPSEC_ID_KEY_ID:
+		return -1;
+#endif
+
+	default:
+		log_print("ipsec_get_id: unknown ID type \"%s\" in "
+		    "section %s", type, section);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * XXX I rather want this function to return a status code, and fail if
+ * we cannot fit the information in the supplied buffer.
+ */
+static void
+ipsec_decode_id(char *buf, size_t size, u_int8_t *id, size_t id_len,
+    int isakmpform)
+{
+	int             id_type;
+	char           *addr = 0, *mask = 0;
+	u_int32_t      *idp;
+
+	if (id) {
+		if (!isakmpform) {
+			/*
+			 * Exchanges and SAs dont carry the IDs in ISAKMP
+			 * form.
+			 */
+			id -= ISAKMP_GEN_SZ;
+			id_len += ISAKMP_GEN_SZ;
+		}
+		id_type = GET_ISAKMP_ID_TYPE(id);
+		idp = (u_int32_t *) (id + ISAKMP_ID_DATA_OFF);
+		switch (id_type) {
+		case IPSEC_ID_IPV4_ADDR:
+			util_ntoa(&addr, AF_INET, id + ISAKMP_ID_DATA_OFF);
+			snprintf(buf, size, "%08x: %s",
+			    decode_32(id + ISAKMP_ID_DATA_OFF), addr);
+			break;
+
+		case IPSEC_ID_IPV4_ADDR_SUBNET:
+			util_ntoa(&addr, AF_INET, id + ISAKMP_ID_DATA_OFF);
+			util_ntoa(&mask, AF_INET, id + ISAKMP_ID_DATA_OFF + 4);
+			snprintf(buf, size, "%08x/%08x: %s/%s",
+			    decode_32(id + ISAKMP_ID_DATA_OFF),
+			decode_32(id + ISAKMP_ID_DATA_OFF + 4), addr, mask);
+			break;
+
+		case IPSEC_ID_IPV6_ADDR:
+			util_ntoa(&addr, AF_INET6, id + ISAKMP_ID_DATA_OFF);
+			snprintf(buf, size, "%08x%08x%08x%08x: %s", *idp,
+			    *(idp + 1), *(idp + 2), *(idp + 3), addr);
+			break;
+
+		case IPSEC_ID_IPV6_ADDR_SUBNET:
+			util_ntoa(&addr, AF_INET6, id + ISAKMP_ID_DATA_OFF);
+			util_ntoa(&mask, AF_INET6, id + ISAKMP_ID_DATA_OFF +
+			    sizeof(struct in6_addr));
+			snprintf(buf, size,
+			    "%08x%08x%08x%08x/%08x%08x%08x%08x: %s/%s", *idp,
+			    *(idp + 1), *(idp + 2), *(idp + 3), *(idp + 4),
+			    *(idp + 5), *(idp + 6), *(idp + 7), addr, mask);
+			break;
+
+		case IPSEC_ID_FQDN:
+		case IPSEC_ID_USER_FQDN:
+			/* String is not NUL terminated, be careful */
+			id_len -= ISAKMP_ID_DATA_OFF;
+			id_len = MIN(id_len, size - 1);
+			memcpy(buf, id + ISAKMP_ID_DATA_OFF, id_len);
+			buf[id_len] = '\0';
+			break;
+
+#ifdef USE_X509
+		case IPSEC_ID_DER_ASN1_DN:
+			addr = x509_DN_string(id + ISAKMP_ID_DATA_OFF,
+			    id_len - ISAKMP_ID_DATA_OFF);
+			if (!addr) {
+				snprintf(buf, size, "unparsable ASN1 DN ID");
+				return;
+			}
+			strlcpy(buf, addr, size);
+			break;
+#endif
+
+		default:
+			snprintf(buf, size, "<id type unknown: %x>", id_type);
+			break;
+		}
+	} else
+		snprintf(buf, size, "<no ipsec id>");
+	if (addr)
+		free(addr);
+	if (mask)
+		free(mask);
+}
+
+char *
+ipsec_decode_ids(char *fmt, u_int8_t *id1, size_t id1_len, u_int8_t *id2,
+    size_t id2_len, int isakmpform)
+{
+	static char     result[1024];
+	char            s_id1[256], s_id2[256];
+
+	ipsec_decode_id(s_id1, sizeof s_id1, id1, id1_len, isakmpform);
+	ipsec_decode_id(s_id2, sizeof s_id2, id2, id2_len, isakmpform);
+
+	snprintf(result, sizeof result, fmt, s_id1, s_id2);
+	return result;
+}
+
+/*
+ * Out of a named section SECTION in the configuration file build an
+ * ISAKMP ID payload.  Ths payload size should be stashed in SZ.
+ * The caller is responsible for freeing the payload.
+ */
+u_int8_t *
+ipsec_build_id(char *section, size_t *sz)
+{
+	struct sockaddr *addr, *mask;
+	u_int8_t       *p;
+	int             id, subnet = 0;
+	u_int8_t        tproto = 0;
+	u_int16_t       port = 0;
+
+	if (ipsec_get_id(section, &id, &addr, &mask, &tproto, &port))
+		return 0;
+
+	if (id == IPSEC_ID_IPV4_ADDR_SUBNET || id == IPSEC_ID_IPV6_ADDR_SUBNET)
+		subnet = 1;
+
+	*sz = ISAKMP_ID_SZ + sockaddr_addrlen(addr);
+	if (subnet)
+		*sz += sockaddr_addrlen(mask);
+
+	p = malloc(*sz);
+	if (!p) {
+		log_print("ipsec_build_id: malloc(%lu) failed",
+		    (unsigned long)*sz);
+		if (subnet)
+			free(mask);
+		free(addr);
+		return 0;
+	}
+	SET_ISAKMP_ID_TYPE(p, id);
+	SET_ISAKMP_ID_DOI_DATA(p, (unsigned char *)"\000\000\000");
+
+	memcpy(p + ISAKMP_ID_DATA_OFF, sockaddr_addrdata(addr),
+	    sockaddr_addrlen(addr));
+	if (subnet)
+		memcpy(p + ISAKMP_ID_DATA_OFF + sockaddr_addrlen(addr),
+		    sockaddr_addrdata(mask), sockaddr_addrlen(mask));
+
+	SET_IPSEC_ID_PROTO(p + ISAKMP_ID_DOI_DATA_OFF, tproto);
+	SET_IPSEC_ID_PORT(p + ISAKMP_ID_DOI_DATA_OFF, port);
+
+	if (subnet)
+		free(mask);
+	free(addr);
+	return p;
+}
+
+/*
+ * copy an ISAKMPD id
+ */
+int
+ipsec_clone_id(u_int8_t **did, size_t *did_len, u_int8_t *id, size_t id_len)
+{
+	if (*did)
+		free(*did);
+
+	if (!id_len || !id) {
+		*did = 0;
+		*did_len = 0;
+		return 0;
+	}
+	*did = malloc(id_len);
+	if (!*did) {
+		*did_len = 0;
+		log_error("ipsec_clone_id: malloc(%lu) failed",
+		    (unsigned long)id_len);
+		return -1;
+	}
+	*did_len = id_len;
+	memcpy(*did, id, id_len);
+
+	return 0;
+}
+
+/*
+ * IPsec-specific PROTO initializations.  SECTION is only set if we are the
+ * initiator thus only usable there.
+ * XXX I want to fix this later.
+ */
+void
+ipsec_proto_init(struct proto *proto, char *section)
+{
+	struct ipsec_proto *iproto = proto->data;
+
+	if (proto->sa->phase == 2)
+		iproto->replay_window = section ? conf_get_num(section,
+		    "ReplayWindow", DEFAULT_REPLAY_WINDOW) :
+		    DEFAULT_REPLAY_WINDOW;
+}
+
+/*
+ * Add a notification payload of type INITIAL CONTACT to MSG if this is
+ * the first contact we have made to our peer.
+ */
+int
+ipsec_initial_contact(struct message *msg)
+{
+	u_int8_t *buf;
+
+	if (ipsec_contacted(msg))
+		return 0;
+
+	buf = malloc(ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN);
+	if (!buf) {
+		log_error("ike_phase_1_initial_contact: malloc (%d) failed",
+		    ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN);
+		return -1;
+	}
+	SET_ISAKMP_NOTIFY_DOI(buf, IPSEC_DOI_IPSEC);
+	SET_ISAKMP_NOTIFY_PROTO(buf, ISAKMP_PROTO_ISAKMP);
+	SET_ISAKMP_NOTIFY_SPI_SZ(buf, ISAKMP_HDR_COOKIES_LEN);
+	SET_ISAKMP_NOTIFY_MSG_TYPE(buf, IPSEC_NOTIFY_INITIAL_CONTACT);
+	memcpy(buf + ISAKMP_NOTIFY_SPI_OFF, msg->isakmp_sa->cookies,
+	    ISAKMP_HDR_COOKIES_LEN);
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_NOTIFY, buf,
+	    ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN, 1)) {
+		free(buf);
+		return -1;
+	}
+	return ipsec_add_contact(msg);
+}
+
+/*
+ * Compare the two contacts pointed to by A and B.  Return negative if
+ * *A < *B, 0 if they are equal, and positive if *A is the largest of them.
+ */
+static int
+addr_cmp(const void *a, const void *b)
+{
+	const struct contact *x = a, *y = b;
+	int             minlen = MIN(x->len, y->len);
+	int             rv = memcmp(x->addr, y->addr, minlen);
+
+	return rv ? rv : (x->len - y->len);
+}
+
+/*
+ * Add the peer that MSG is bound to as an address we don't want to send
+ * INITIAL CONTACT too from now on.  Do not call this function with a
+ * specific address duplicate times. We want fast lookup, speed of insertion
+ * is unimportant, if this is to scale.
+ */
+static int
+ipsec_add_contact(struct message *msg)
+{
+	struct contact *new_contacts;
+	struct sockaddr *dst, *addr;
+	int             cnt;
+
+	if (contact_cnt == contact_limit) {
+		cnt = contact_limit ? 2 * contact_limit : 64;
+		new_contacts = realloc(contacts, cnt * sizeof contacts[0]);
+		if (!new_contacts) {
+			log_error("ipsec_add_contact: "
+			    "realloc (%p, %lu) failed", contacts,
+			    cnt * (unsigned long) sizeof contacts[0]);
+			return -1;
+		}
+		contact_limit = cnt;
+		contacts = new_contacts;
+	}
+	msg->transport->vtbl->get_dst(msg->transport, &dst);
+	addr = malloc(sysdep_sa_len(dst));
+	if (!addr) {
+		log_error("ipsec_add_contact: malloc (%d) failed",
+		    sysdep_sa_len(dst));
+		return -1;
+	}
+	memcpy(addr, dst, sysdep_sa_len(dst));
+	contacts[contact_cnt].addr = addr;
+	contacts[contact_cnt++].len = sysdep_sa_len(dst);
+
+	/*
+	 * XXX There are better algorithms for already mostly-sorted data like
+	 * this, but only qsort is standard.  I will someday do this inline.
+         */
+	qsort(contacts, contact_cnt, sizeof *contacts, addr_cmp);
+	return 0;
+}
+
+/* Return true if the recipient of MSG has already been contacted.  */
+static int
+ipsec_contacted(struct message *msg)
+{
+	struct contact  contact;
+
+	msg->transport->vtbl->get_dst(msg->transport, &contact.addr);
+	contact.len = sysdep_sa_len(contact.addr);
+	return contacts ? (bsearch(&contact, contacts, contact_cnt,
+	    sizeof *contacts, addr_cmp) != 0) : 0;
+}
+
+/* Add a HASH for to MSG.  */
+u_int8_t *
+ipsec_add_hash_payload(struct message *msg, size_t hashsize)
+{
+	u_int8_t *buf;
+
+	buf = malloc(ISAKMP_HASH_SZ + hashsize);
+	if (!buf) {
+		log_error("ipsec_add_hash_payload: malloc (%lu) failed",
+		    ISAKMP_HASH_SZ + (unsigned long) hashsize);
+		return 0;
+	}
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_HASH, buf,
+	    ISAKMP_HASH_SZ + hashsize, 1)) {
+		free(buf);
+		return 0;
+	}
+	return buf;
+}
+
+/* Fill in the HASH payload of MSG.  */
+int
+ipsec_fill_in_hash(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct sa      *isakmp_sa = msg->isakmp_sa;
+	struct ipsec_sa *isa = isakmp_sa->data;
+	struct hash    *hash = hash_get(isa->hash);
+	struct prf     *prf;
+	struct payload *payload;
+	u_int8_t       *buf;
+	u_int32_t       i;
+	char            header[80];
+
+	/* If no SKEYID_a, we need not do anything.  */
+	if (!isa->skeyid_a)
+		return 0;
+
+	payload = payload_first(msg, ISAKMP_PAYLOAD_HASH);
+	if (!payload) {
+		log_print("ipsec_fill_in_hash: no HASH payload found");
+		return -1;
+	}
+	buf = payload->p;
+
+	/* Allocate the prf and start calculating our HASH(1).  */
+	LOG_DBG_BUF((LOG_MISC, 90, "ipsec_fill_in_hash: SKEYID_a",
+	    isa->skeyid_a, isa->skeyid_len));
+	prf = prf_alloc(isa->prf_type, hash->type, isa->skeyid_a,
+	    isa->skeyid_len);
+	if (!prf)
+		return -1;
+
+	prf->Init(prf->prfctx);
+	LOG_DBG_BUF((LOG_MISC, 90, "ipsec_fill_in_hash: message_id",
+	    exchange->message_id, ISAKMP_HDR_MESSAGE_ID_LEN));
+	prf->Update(prf->prfctx, exchange->message_id,
+	    ISAKMP_HDR_MESSAGE_ID_LEN);
+
+	/* Loop over all payloads after HASH(1).  */
+	for (i = 2; i < msg->iovlen; i++) {
+		/* XXX Misleading payload type printouts.  */
+		snprintf(header, sizeof header,
+		    "ipsec_fill_in_hash: payload %d after HASH(1)", i - 1);
+		LOG_DBG_BUF((LOG_MISC, 90, header, msg->iov[i].iov_base,
+		    msg->iov[i].iov_len));
+		prf->Update(prf->prfctx, msg->iov[i].iov_base,
+		    msg->iov[i].iov_len);
+	}
+	prf->Final(buf + ISAKMP_HASH_DATA_OFF, prf->prfctx);
+	prf_free(prf);
+	LOG_DBG_BUF((LOG_MISC, 80, "ipsec_fill_in_hash: HASH(1)", buf +
+	    ISAKMP_HASH_DATA_OFF, hash->hashsize));
+
+	return 0;
+}
+
+/* Add a HASH payload to MSG, if we have an ISAKMP SA we're protected by.  */
+static int
+ipsec_informational_pre_hook(struct message *msg)
+{
+	struct sa      *isakmp_sa = msg->isakmp_sa;
+	struct ipsec_sa *isa;
+	struct hash    *hash;
+
+	if (!isakmp_sa)
+		return 0;
+	isa = isakmp_sa->data;
+	hash = hash_get(isa->hash);
+	return ipsec_add_hash_payload(msg, hash->hashsize) == 0;
+}
+
+/*
+ * Fill in the HASH payload in MSG, if we have an ISAKMP SA we're protected by.
+ */
+static int
+ipsec_informational_post_hook(struct message *msg)
+{
+	if (!msg->isakmp_sa)
+		return 0;
+	return ipsec_fill_in_hash(msg);
+}
+
+ssize_t
+ipsec_id_size(char *section, u_int8_t *id)
+{
+	char *type, *data;
+
+	type = conf_get_str(section, "ID-type");
+	if (!type) {
+		log_print("ipsec_id_size: section %s has no \"ID-type\" tag",
+		    section);
+		return -1;
+	}
+	*id = constant_value(ipsec_id_cst, type);
+	switch (*id) {
+	case IPSEC_ID_IPV4_ADDR:
+		return sizeof(struct in_addr);
+	case IPSEC_ID_IPV4_ADDR_SUBNET:
+		return 2 * sizeof(struct in_addr);
+	case IPSEC_ID_IPV6_ADDR:
+		return sizeof(struct in6_addr);
+	case IPSEC_ID_IPV6_ADDR_SUBNET:
+		return 2 * sizeof(struct in6_addr);
+	case IPSEC_ID_FQDN:
+	case IPSEC_ID_USER_FQDN:
+	case IPSEC_ID_KEY_ID:
+	case IPSEC_ID_DER_ASN1_DN:
+	case IPSEC_ID_DER_ASN1_GN:
+		data = conf_get_str(section, "Name");
+		if (!data) {
+			log_print("ipsec_id_size: "
+			    "section %s has no \"Name\" tag", section);
+			return -1;
+		}
+		return strlen(data);
+	}
+	log_print("ipsec_id_size: unrecognized/unsupported ID-type %d (%s)",
+	    *id, type);
+	return -1;
+}
+
+/*
+ * Generate a string version of the ID.
+ */
+char *
+ipsec_id_string(u_int8_t *id, size_t id_len)
+{
+	char           *buf = 0;
+	char           *addrstr = 0;
+	size_t          len, size;
+
+	/*
+	 * XXX Real ugly way of making the offsets correct.  Be aware that id
+	 * now will point before the actual buffer and cannot be dereferenced
+	 * without an offset larger than or equal to ISAKM_GEN_SZ.
+         */
+	id -= ISAKMP_GEN_SZ;
+
+	/* This is the actual length of the ID data field.  */
+	id_len += ISAKMP_GEN_SZ - ISAKMP_ID_DATA_OFF;
+
+	/*
+	 * Conservative allocation.
+	 * XXX I think the ASN1 DN case can be thought through to give a better
+	 * estimate.
+         */
+	size = MAX(sizeof "ipv6/ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff",
+	    sizeof "asn1_dn/" + id_len - ISAKMP_ID_DATA_OFF);
+	buf = malloc(size);
+	if (!buf)
+		/* XXX Log?  */
+		goto fail;
+
+	switch (GET_ISAKMP_ID_TYPE(id)) {
+	case IPSEC_ID_IPV4_ADDR:
+		if (id_len < sizeof(struct in_addr))
+			goto fail;
+		util_ntoa(&addrstr, AF_INET, id + ISAKMP_ID_DATA_OFF);
+		if (!addrstr)
+			goto fail;
+		snprintf(buf, size, "ipv4/%s", addrstr);
+		break;
+
+	case IPSEC_ID_IPV6_ADDR:
+		if (id_len < sizeof(struct in6_addr))
+			goto fail;
+		util_ntoa(&addrstr, AF_INET6, id + ISAKMP_ID_DATA_OFF);
+		if (!addrstr)
+			goto fail;
+		snprintf(buf, size, "ipv6/%s", addrstr);
+		break;
+
+	case IPSEC_ID_FQDN:
+	case IPSEC_ID_USER_FQDN:
+		strlcpy(buf,
+		GET_ISAKMP_ID_TYPE(id) == IPSEC_ID_FQDN ? "fqdn/" : "ufqdn/",
+		    size);
+		len = strlen(buf);
+
+		memcpy(buf + len, id + ISAKMP_ID_DATA_OFF, id_len);
+		*(buf + len + id_len) = '\0';
+		break;
+
+#ifdef USE_X509
+	case IPSEC_ID_DER_ASN1_DN:
+		strlcpy(buf, "asn1_dn/", size);
+		len = strlen(buf);
+		addrstr = x509_DN_string(id + ISAKMP_ID_DATA_OFF,
+		    id_len - ISAKMP_ID_DATA_OFF);
+		if (!addrstr)
+			goto fail;
+		if (size < len + strlen(addrstr) + 1)
+			goto fail;
+		strlcpy(buf + len, addrstr, size - len);
+		break;
+#endif
+
+	default:
+		/* Unknown type.  */
+		LOG_DBG((LOG_MISC, 10,
+		    "ipsec_id_string: unknown identity type %d\n",
+		    GET_ISAKMP_ID_TYPE(id)));
+		goto fail;
+	}
+
+	if (addrstr)
+		free(addrstr);
+	return buf;
+
+fail:
+	if (buf)
+		free(buf);
+	if (addrstr)
+		free(addrstr);
+	return 0;
+}