adden new isakmpd

1 files changed, 1396 insertions, 0 deletions

diff --git a/keyexchange/isakmpd-20041012/ike_phase_1.c b/keyexchange/isakmpd-20041012/ike_phase_1.c
new file mode 100644
index 0000000..7f72a25
--- /dev/null
+++ b/keyexchange/isakmpd-20041012/ike_phase_1.c
@@ -0,0 +1,1396 @@
+/* $OpenBSD: ike_phase_1.c,v 1.56 2004/08/08 19:11:06 deraadt Exp $	 */
+/* $EOM: ike_phase_1.c,v 1.31 2000/12/11 23:47:56 niklas Exp $	 */
+
+/*
+ * Copyright (c) 1999, 2000 Niklas Hallqvist.  All rights reserved.
+ * Copyright (c) 1999, 2000 Angelos D. Keromytis.  All rights reserved.
+ * Copyright (c) 2001, 2004 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 <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"
+#ifdef USE_DPD
+#include "dpd.h"
+#endif
+#include "exchange.h"
+#include "hash.h"
+#include "ike_auth.h"
+#include "ike_phase_1.h"
+#include "ipsec.h"
+#include "ipsec_doi.h"
+#include "isakmp.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 "transport.h"
+#include "util.h"
+
+static int      attribute_unacceptable(u_int16_t, u_int8_t *, u_int16_t,
+    void *);
+static int	ike_phase_1_validate_prop(struct exchange *, struct sa *,
+    struct sa *);
+
+/* Offer a set of transforms to the responder in the MSG message.  */
+int
+ike_phase_1_initiator_send_SA(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	u_int8_t       *proposal = 0, *sa_buf = 0, *saved_nextp, *attr;
+	u_int8_t      **transform = 0;
+	size_t          transforms_len = 0, proposal_len, sa_len;
+	size_t         *transform_len = 0;
+	struct conf_list *conf, *life_conf;
+	struct conf_list_node *xf, *life;
+	int             value, update_nextp;
+	size_t          i;
+	struct payload *p;
+	struct proto   *proto;
+	struct proto_attr *pa;
+	int             group_desc = -1, new_group_desc;
+
+	/* Get the list of transforms.  */
+	conf = conf_get_list(exchange->policy, "Transforms");
+	if (!conf)
+		return -1;
+
+	transform = calloc(conf->cnt, sizeof *transform);
+	if (!transform) {
+		log_error("ike_phase_1_initiator_send_SA: calloc (%lu, %lu) "
+		    "failed", (u_long)conf->cnt, (u_long) sizeof *transform);
+		goto bail_out;
+	}
+	transform_len = calloc(conf->cnt, sizeof *transform_len);
+	if (!transform_len) {
+		log_error("ike_phase_1_initiator_send_SA: calloc (%lu, %lu) "
+		    "failed", (u_long)conf->cnt,
+		    (u_long) sizeof *transform_len);
+		goto bail_out;
+	}
+	for (xf = TAILQ_FIRST(&conf->fields), i = 0; i < conf->cnt;
+	    i++, xf = TAILQ_NEXT(xf, link)) {
+		/* XXX The sizing needs to be dynamic.  */
+		transform[i] = malloc(ISAKMP_TRANSFORM_SA_ATTRS_OFF +
+		    16 * ISAKMP_ATTR_VALUE_OFF);
+		if (!transform[i]) {
+			log_error("ike_phase_1_initiator_send_SA: malloc (%d) "
+			    "failed", ISAKMP_TRANSFORM_SA_ATTRS_OFF +
+			    16 * ISAKMP_ATTR_VALUE_OFF);
+			goto bail_out;
+		}
+		SET_ISAKMP_TRANSFORM_NO(transform[i], i);
+		SET_ISAKMP_TRANSFORM_ID(transform[i], IPSEC_TRANSFORM_KEY_IKE);
+		SET_ISAKMP_TRANSFORM_RESERVED(transform[i], 0);
+
+		attr = transform[i] + ISAKMP_TRANSFORM_SA_ATTRS_OFF;
+
+		if (attribute_set_constant(xf->field, "ENCRYPTION_ALGORITHM",
+		    ike_encrypt_cst, IKE_ATTR_ENCRYPTION_ALGORITHM, &attr))
+			goto bail_out;
+
+		if (attribute_set_constant(xf->field, "HASH_ALGORITHM",
+		    ike_hash_cst, IKE_ATTR_HASH_ALGORITHM, &attr))
+			goto bail_out;
+
+		if (attribute_set_constant(xf->field, "AUTHENTICATION_METHOD",
+		    ike_auth_cst, IKE_ATTR_AUTHENTICATION_METHOD, &attr))
+			goto bail_out;
+
+		if (attribute_set_constant(xf->field, "GROUP_DESCRIPTION",
+		    ike_group_desc_cst, IKE_ATTR_GROUP_DESCRIPTION, &attr)) {
+			/*
+			 * If no group description exists, try looking for
+			 * a user-defined one.
+			 */
+			if (attribute_set_constant(xf->field, "GROUP_TYPE",
+			    ike_group_cst, IKE_ATTR_GROUP_TYPE, &attr))
+				goto bail_out;
+
+#if 0
+			if (attribute_set_bignum(xf->field, "GROUP_PRIME",
+			    IKE_ATTR_GROUP_PRIME, &attr))
+				goto bail_out;
+
+			if (attribute_set_bignum(xf->field,
+			    "GROUP_GENERATOR_2", IKE_ATTR_GROUP_GENERATOR_2,
+			    &attr))
+				goto bail_out;
+
+			if (attribute_set_bignum(xf->field,
+			    "GROUP_GENERATOR_2", IKE_ATTR_GROUP_GENERATOR_2,
+			    &attr))
+				goto bail_out;
+
+			if (attribute_set_bignum(xf->field, "GROUP_CURVE_A",
+			    IKE_ATTR_GROUP_CURVE_A, &attr))
+				goto bail_out;
+
+			if (attribute_set_bignum(xf->field, "GROUP_CURVE_B",
+			    IKE_ATTR_GROUP_CURVE_B, &attr))
+				goto bail_out;
+#endif
+		}
+		/*
+		 * Life durations are special, we should be able to specify
+		 * several, one per type.
+		 */
+		life_conf = conf_get_list(xf->field, "Life");
+		if (life_conf) {
+			for (life = TAILQ_FIRST(&life_conf->fields); life;
+			    life = TAILQ_NEXT(life, link)) {
+				attribute_set_constant(life->field,
+				    "LIFE_TYPE", ike_duration_cst,
+				    IKE_ATTR_LIFE_TYPE, &attr);
+
+				/*
+				 * XXX Deals with 16 and 32 bit lifetimes
+				 * only
+				 */
+				value = conf_get_num(life->field,
+				    "LIFE_DURATION", 0);
+				if (value) {
+					if (value <= 0xffff)
+						attr = attribute_set_basic(
+						    attr,
+						    IKE_ATTR_LIFE_DURATION,
+						    value);
+					else {
+						value = htonl(value);
+						attr = attribute_set_var(attr,
+						    IKE_ATTR_LIFE_DURATION,
+						    (u_int8_t *)&value,
+						    sizeof value);
+					}
+				}
+			}
+			conf_free_list(life_conf);
+		}
+		attribute_set_constant(xf->field, "PRF", ike_prf_cst,
+		    IKE_ATTR_PRF, &attr);
+
+		value = conf_get_num(xf->field, "KEY_LENGTH", 0);
+		if (value)
+			attr = attribute_set_basic(attr, IKE_ATTR_KEY_LENGTH,
+			    value);
+
+		value = conf_get_num(xf->field, "FIELD_SIZE", 0);
+		if (value)
+			attr = attribute_set_basic(attr, IKE_ATTR_FIELD_SIZE,
+			    value);
+
+		value = conf_get_num(xf->field, "GROUP_ORDER", 0);
+		if (value)
+			attr = attribute_set_basic(attr, IKE_ATTR_GROUP_ORDER,
+			    value);
+
+		/* Record the real transform size.  */
+		transforms_len += transform_len[i] = attr - transform[i];
+
+		/* XXX I don't like exchange-specific stuff in here.  */
+		if (exchange->type == ISAKMP_EXCH_AGGRESSIVE) {
+			/*
+			 * Make sure that if a group description is specified,
+			 * it is specified for all transforms equally.
+			 */
+			attr = (u_int8_t *) conf_get_str(xf->field,
+			    "GROUP_DESCRIPTION");
+			new_group_desc =
+			    attr ? constant_value(ike_group_desc_cst,
+				(char *) attr) : 0;
+			if (group_desc == -1)
+				group_desc = new_group_desc;
+			else if (group_desc != new_group_desc) {
+				log_print("ike_phase_1_initiator_send_SA: "
+				    "differing group descriptions in a "
+				    "proposal");
+				goto bail_out;
+			}
+		}
+		/*
+		 * We need to check that we actually support our
+		 * configuration.
+		 */
+		if (attribute_map(transform[i] + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+		    transform_len[i] - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+		    exchange->doi->is_attribute_incompatible, msg)) {
+			log_print("ike_phase_1_initiator_send_SA: "
+			    "section [%s] has unsupported attribute(s)",
+			    xf->field);
+			goto bail_out;
+		}
+	}
+
+	/* XXX I don't like exchange-specific stuff in here.  */
+	if (exchange->type == ISAKMP_EXCH_AGGRESSIVE)
+		ie->group = group_get(group_desc);
+
+	proposal_len = ISAKMP_PROP_SPI_OFF;
+	proposal = malloc(proposal_len);
+	if (!proposal) {
+		log_error("ike_phase_1_initiator_send_SA: malloc (%lu) failed",
+		    (unsigned long) proposal_len);
+		goto bail_out;
+	}
+	SET_ISAKMP_PROP_NO(proposal, 1);
+	SET_ISAKMP_PROP_PROTO(proposal, ISAKMP_PROTO_ISAKMP);
+	SET_ISAKMP_PROP_SPI_SZ(proposal, 0);
+	SET_ISAKMP_PROP_NTRANSFORMS(proposal, conf->cnt);
+
+	/* XXX I would like to see this factored out.  */
+	proto = calloc(1, sizeof *proto);
+	if (!proto) {
+		log_error("ike_phase_1_initiator_send_SA: "
+		    "calloc (1, %lu) failed", (unsigned long) sizeof *proto);
+		goto bail_out;
+	}
+	proto->no = 1;
+	proto->proto = ISAKMP_PROTO_ISAKMP;
+	proto->sa = TAILQ_FIRST(&exchange->sa_list);
+	proto->xf_cnt = conf->cnt;
+	TAILQ_INIT(&proto->xfs);
+	for (i = 0; i < proto->xf_cnt; i++) {
+		pa = (struct proto_attr *) calloc(1, sizeof *pa);
+		if (!pa)
+			goto bail_out;
+		pa->len = transform_len[i];
+		pa->attrs = (u_int8_t *) malloc(pa->len);
+		if (!pa->attrs) {
+			free(pa);
+			goto bail_out;
+		}
+		memcpy(pa->attrs, transform[i], pa->len);
+		TAILQ_INSERT_TAIL(&proto->xfs, pa, next);
+	}
+	TAILQ_INSERT_TAIL(&TAILQ_FIRST(&exchange->sa_list)->protos, proto,
+	    link);
+
+	sa_len = ISAKMP_SA_SIT_OFF + IPSEC_SIT_SIT_LEN;
+	sa_buf = malloc(sa_len);
+	if (!sa_buf) {
+		log_error("ike_phase_1_initiator_send_SA: malloc (%lu) failed",
+		    (unsigned long) sa_len);
+		goto bail_out;
+	}
+	SET_ISAKMP_SA_DOI(sa_buf, IPSEC_DOI_IPSEC);
+	SET_IPSEC_SIT_SIT(sa_buf + ISAKMP_SA_SIT_OFF, IPSEC_SIT_IDENTITY_ONLY);
+
+	/*
+	 * Add the payloads.  As this is a SA, we need to recompute the
+	 * lengths of the payloads containing others.
+	 */
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_SA, sa_buf, sa_len, 1))
+		goto bail_out;
+	SET_ISAKMP_GEN_LENGTH(sa_buf,
+	    sa_len + proposal_len + transforms_len);
+	sa_buf = 0;
+
+	saved_nextp = msg->nextp;
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_PROPOSAL, proposal,
+	    proposal_len, 0))
+		goto bail_out;
+	SET_ISAKMP_GEN_LENGTH(proposal, proposal_len + transforms_len);
+	proposal = 0;
+
+	update_nextp = 0;
+	for (i = 0; i < conf->cnt; i++) {
+		if (message_add_payload(msg, ISAKMP_PAYLOAD_TRANSFORM,
+		    transform[i], transform_len[i], update_nextp))
+			goto bail_out;
+		update_nextp = 1;
+		transform[i] = 0;
+	}
+	msg->nextp = saved_nextp;
+
+	/* Save SA payload body in ie->sa_i_b, length ie->sa_i_b_len.  */
+	ie->sa_i_b_len = sa_len + proposal_len + transforms_len -
+	    ISAKMP_GEN_SZ;
+	ie->sa_i_b = malloc(ie->sa_i_b_len);
+	if (!ie->sa_i_b) {
+		log_error("ike_phase_1_initiator_send_SA: malloc (%lu) failed",
+		    (unsigned long) ie->sa_i_b_len);
+		goto bail_out;
+	}
+	memcpy(ie->sa_i_b,
+	    payload_first(msg, ISAKMP_PAYLOAD_SA)->p + ISAKMP_GEN_SZ,
+	    sa_len - ISAKMP_GEN_SZ);
+	memcpy(ie->sa_i_b + sa_len - ISAKMP_GEN_SZ,
+	    payload_first(msg, ISAKMP_PAYLOAD_PROPOSAL)->p, proposal_len);
+	transforms_len = 0;
+	for (i = 0, p = payload_first(msg, ISAKMP_PAYLOAD_TRANSFORM);
+	    i < conf->cnt; i++, p = TAILQ_NEXT(p, link)) {
+		memcpy(ie->sa_i_b + sa_len + proposal_len + transforms_len -
+		    ISAKMP_GEN_SZ, p->p, transform_len[i]);
+		transforms_len += transform_len[i];
+	}
+
+#if defined (USE_NAT_TRAVERSAL)
+	/* Advertise NAT-T capability.  */
+	if (nat_t_add_vendor_payloads(msg))
+		goto bail_out;
+#endif
+
+#if defined (USE_DPD)
+	/* Advertise DPD capability.  */
+	if (dpd_add_vendor_payload(msg))
+		goto bail_out;
+#endif
+
+	conf_free_list(conf);
+	free(transform);
+	free(transform_len);
+	return 0;
+
+bail_out:
+	if (sa_buf)
+		free(sa_buf);
+	if (proposal)
+		free(proposal);
+	if (transform) {
+		for (i = 0; i < conf->cnt; i++)
+			if (transform[i])
+				free(transform[i]);
+		free(transform);
+	}
+	if (transform_len)
+		free(transform_len);
+	conf_free_list(conf);
+	return -1;
+}
+
+/* Figure out what transform the responder chose.  */
+int
+ike_phase_1_initiator_recv_SA(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct sa      *sa = TAILQ_FIRST(&exchange->sa_list);
+	struct ipsec_exch *ie = exchange->data;
+	struct ipsec_sa *isa = sa->data;
+	struct payload *sa_p = payload_first(msg, ISAKMP_PAYLOAD_SA);
+	struct payload *prop = payload_first(msg, ISAKMP_PAYLOAD_PROPOSAL);
+	struct payload *xf = payload_first(msg, ISAKMP_PAYLOAD_TRANSFORM);
+
+	/*
+	 * IKE requires that only one SA with only one proposal exists and
+	 * since we are getting an answer on our transform offer, only one
+	 * transform.
+	 */
+	if (TAILQ_NEXT(sa_p, link) || TAILQ_NEXT(prop, link) ||
+	    TAILQ_NEXT(xf, link)) {
+		log_print("ike_phase_1_initiator_recv_SA: "
+		    "multiple SA, proposal or transform payloads in phase 1");
+		/* XXX Is there a better notification type?  */
+		message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
+		return -1;
+	}
+	/* Check that the chosen transform matches an offer.  */
+	if (message_negotiate_sa(msg, ike_phase_1_validate_prop) ||
+	    !TAILQ_FIRST(&sa->protos))
+		return -1;
+
+	ipsec_decode_transform(msg, sa, TAILQ_FIRST(&sa->protos), xf->p);
+
+	/* XXX I don't like exchange-specific stuff in here.  */
+	if (exchange->type != ISAKMP_EXCH_AGGRESSIVE)
+		ie->group = group_get(isa->group_desc);
+
+	/* Mark the SA as handled.  */
+	sa_p->flags |= PL_MARK;
+
+	return 0;
+}
+
+/* Send our public DH value and a nonce to the responder.  */
+int
+ike_phase_1_initiator_send_KE_NONCE(struct message *msg)
+{
+	struct ipsec_exch *ie = msg->exchange->data;
+
+	ie->g_x_len = dh_getlen(ie->group);
+
+	/* XXX I want a better way to specify the nonce's size.  */
+	return ike_phase_1_send_KE_NONCE(msg, 16);
+}
+
+/* Accept responder's public DH value and nonce.  */
+int
+ike_phase_1_initiator_recv_KE_NONCE(struct message *msg)
+{
+	if (ike_phase_1_recv_KE_NONCE(msg))
+		return -1;
+
+	return ike_phase_1_post_exchange_KE_NONCE(msg);
+}
+
+/*
+ * Accept a set of transforms offered by the initiator and chose one we can
+ * handle.
+ */
+int
+ike_phase_1_responder_recv_SA(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct sa      *sa = TAILQ_FIRST(&exchange->sa_list);
+	struct ipsec_sa *isa = sa->data;
+	struct payload *sa_p = payload_first(msg, ISAKMP_PAYLOAD_SA);
+	struct payload *prop = payload_first(msg, ISAKMP_PAYLOAD_PROPOSAL);
+	struct ipsec_exch *ie = exchange->data;
+
+	/* Mark the SA as handled.  */
+	sa_p->flags |= PL_MARK;
+
+	/* IKE requires that only one SA with only one proposal exists.  */
+	if (TAILQ_NEXT(sa_p, link) || TAILQ_NEXT(prop, link)) {
+		log_print("ike_phase_1_responder_recv_SA: "
+		    "multiple SA or proposal payloads in phase 1");
+		/* XXX Is there a better notification type?  */
+		message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
+		return -1;
+	}
+	/* Chose a transform from the SA.  */
+	if (message_negotiate_sa(msg, ike_phase_1_validate_prop) ||
+	    !TAILQ_FIRST(&sa->protos))
+		return -1;
+
+	/* XXX Move into message_negotiate_sa?  */
+	ipsec_decode_transform(msg, sa, TAILQ_FIRST(&sa->protos),
+	    TAILQ_FIRST(&sa->protos)->chosen->p);
+
+	ie->group = group_get(isa->group_desc);
+
+	/*
+	 * Check that the mandatory attributes: encryption, hash,
+	 * authentication method and Diffie-Hellman group description, has
+	 * been supplied.
+	 */
+	if (!exchange->crypto || !ie->hash || !ie->ike_auth || !ie->group) {
+		message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
+		return -1;
+	}
+	/* Save the body for later hash computation.  */
+	ie->sa_i_b_len = GET_ISAKMP_GEN_LENGTH(sa_p->p) - ISAKMP_GEN_SZ;
+	ie->sa_i_b = malloc(ie->sa_i_b_len);
+	if (!ie->sa_i_b) {
+		/* XXX How to notify peer?  */
+		log_error("ike_phase_1_responder_recv_SA: malloc (%lu) failed",
+		    (unsigned long) ie->sa_i_b_len);
+		return -1;
+	}
+	memcpy(ie->sa_i_b, sa_p->p + ISAKMP_GEN_SZ, ie->sa_i_b_len);
+	return 0;
+}
+
+/* Reply with the transform we chose.  */
+int
+ike_phase_1_responder_send_SA(struct message *msg)
+{
+	/* Add the SA payload with the transform that was chosen.  */
+	if (message_add_sa_payload(msg))
+		return -1;
+
+#if defined (USE_NAT_TRAVERSAL)
+	/* Advertise NAT-T capability.  */
+	if (nat_t_add_vendor_payloads(msg))
+		return -1;
+#endif
+
+#if defined (USE_DPD)
+	/* Advertise DPD capability.  */
+	if (dpd_add_vendor_payload(msg))
+		return -1;
+#endif
+	return 0;
+}
+
+/* Send our public DH value and a nonce to the peer.  */
+int
+ike_phase_1_send_KE_NONCE(struct message *msg, size_t nonce_sz)
+{
+	/* Public DH key.  */
+	if (ipsec_gen_g_x(msg)) {
+		/* XXX How to log and notify peer?  */
+		return -1;
+	}
+	/* Generate a nonce, and add it to the message.  */
+	if (exchange_gen_nonce(msg, nonce_sz)) {
+		/* XXX Log?  */
+		return -1;
+	}
+	/* Try to add certificates which are acceptable for the CERTREQs */
+	if (exchange_add_certs(msg)) {
+		/* XXX Log? */
+		return -1;
+	}
+#if defined (USE_NAT_TRAVERSAL)
+	/* If this exchange uses NAT-Traversal, add NAT-D payloads now.  */
+	if (msg->exchange->flags & EXCHANGE_FLAG_NAT_T_CAP_PEER)
+		if (nat_t_exchange_add_nat_d(msg)) {
+			/* XXX Log? */
+			return -1;
+		}
+#endif
+	return 0;
+}
+
+/* Receive our peer's public DH value and nonce.  */
+int
+ike_phase_1_recv_KE_NONCE(struct message *msg)
+{
+	/* Copy out the initiator's DH public value.  */
+	if (ipsec_save_g_x(msg)) {
+		/* XXX How to log and notify peer?  */
+		return -1;
+	}
+	/* Copy out the initiator's nonce.  */
+	if (exchange_save_nonce(msg)) {
+		/* XXX How to log and notify peer?  */
+		return -1;
+	}
+	/* Copy out the initiator's cert requests.  */
+	if (exchange_save_certreq(msg)) {
+		/* XXX How to log and notify peer?  */
+		return -1;
+	}
+#if defined (USE_NAT_TRAVERSAL)
+	/* MainMode: Check for NAT-D payloads and contents.  */
+	if (msg->exchange->type == ISAKMP_EXCH_ID_PROT &&
+	    msg->exchange->flags & EXCHANGE_FLAG_NAT_T_CAP_PEER)
+		(void)nat_t_exchange_check_nat_d(msg);
+#endif
+	return 0;
+}
+
+/*
+ * Compute DH values and key material.  This is done in a post-send function
+ * as that means we can do parallel work in both the initiator and responder
+ * thus speeding up exchanges.
+ */
+int
+ike_phase_1_post_exchange_KE_NONCE(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	struct prf     *prf;
+	struct hash    *hash = ie->hash;
+	enum cryptoerr  err;
+
+	/* Compute Diffie-Hellman shared value.  */
+	ie->g_xy = malloc(ie->g_x_len);
+	if (!ie->g_xy) {
+		/* XXX How to notify peer?  */
+		log_error("ike_phase_1_post_exchange_KE_NONCE: "
+		    "malloc (%lu) failed", (unsigned long) ie->g_x_len);
+		return -1;
+	}
+	if (dh_create_shared(ie->group, ie->g_xy,
+	    exchange->initiator ? ie->g_xr : ie->g_xi)) {
+		log_print("ike_phase_1_post_exchange_KE_NONCE: "
+		    "dh_create_shared failed");
+		return -1;
+	}
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80,
+	    "ike_phase_1_post_exchange_KE_NONCE: g^xy", ie->g_xy,
+	    ie->g_x_len));
+
+	/* Compute the SKEYID depending on the authentication method.  */
+	ie->skeyid = ie->ike_auth->gen_skeyid(exchange, &ie->skeyid_len);
+	if (!ie->skeyid) {
+		/* XXX Log and teardown?  */
+		return -1;
+	}
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80,
+	    "ike_phase_1_post_exchange_KE_NONCE: SKEYID", ie->skeyid,
+	    ie->skeyid_len));
+
+	/* SKEYID_d.  */
+	ie->skeyid_d = malloc(ie->skeyid_len);
+	if (!ie->skeyid_d) {
+		/* XXX How to notify peer?  */
+		log_error("ike_phase_1_post_exchange_KE_NONCE: "
+		    "malloc (%lu) failed", (unsigned long) ie->skeyid_len);
+		return -1;
+	}
+	prf = prf_alloc(ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len);
+	if (!prf) {
+		/* XXX Log and teardown?  */
+		return -1;
+	}
+	prf->Init(prf->prfctx);
+	prf->Update(prf->prfctx, ie->g_xy, ie->g_x_len);
+	prf->Update(prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN);
+	prf->Update(prf->prfctx, (unsigned char *) "\0", 1);
+	prf->Final(ie->skeyid_d, prf->prfctx);
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80,
+	    "ike_phase_1_post_exchange_KE_NONCE: SKEYID_d", ie->skeyid_d,
+	    ie->skeyid_len));
+
+	/* SKEYID_a.  */
+	ie->skeyid_a = malloc(ie->skeyid_len);
+	if (!ie->skeyid_a) {
+		log_error("ike_phase_1_post_exchange_KE_NONCE: "
+		    "malloc (%lu) failed", (unsigned long) ie->skeyid_len);
+		prf_free(prf);
+		return -1;
+	}
+	prf->Init(prf->prfctx);
+	prf->Update(prf->prfctx, ie->skeyid_d, ie->skeyid_len);
+	prf->Update(prf->prfctx, ie->g_xy, ie->g_x_len);
+	prf->Update(prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN);
+	prf->Update(prf->prfctx, (unsigned char *) "\1", 1);
+	prf->Final(ie->skeyid_a, prf->prfctx);
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80,
+	    "ike_phase_1_post_exchange_KE_NONCE: SKEYID_a", ie->skeyid_a,
+	    ie->skeyid_len));
+
+	/* SKEYID_e.  */
+	ie->skeyid_e = malloc(ie->skeyid_len);
+	if (!ie->skeyid_e) {
+		/* XXX How to notify peer?  */
+		log_error("ike_phase_1_post_exchange_KE_NONCE: "
+		    "malloc (%lu) failed", (unsigned long) ie->skeyid_len);
+		prf_free(prf);
+		return -1;
+	}
+	prf->Init(prf->prfctx);
+	prf->Update(prf->prfctx, ie->skeyid_a, ie->skeyid_len);
+	prf->Update(prf->prfctx, ie->g_xy, ie->g_x_len);
+	prf->Update(prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN);
+	prf->Update(prf->prfctx, (unsigned char *) "\2", 1);
+	prf->Final(ie->skeyid_e, prf->prfctx);
+	prf_free(prf);
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80,
+	    "ike_phase_1_post_exchange_KE_NONCE: SKEYID_e", ie->skeyid_e,
+	    ie->skeyid_len));
+
+	/* Key length determination.  */
+	if (!exchange->key_length)
+		exchange->key_length = exchange->crypto->keymax;
+
+	/* Derive a longer key from skeyid_e */
+	if (ie->skeyid_len < exchange->key_length) {
+		u_int16_t       len, keylen;
+		u_int8_t       *key, *p;
+
+		prf = prf_alloc(ie->prf_type, hash->type, ie->skeyid_e,
+		    ie->skeyid_len);
+		if (!prf) {
+			/* XXX - notify peer */
+			return -1;
+		}
+		/* Make keylen a multiple of prf->blocksize */
+		keylen = exchange->key_length;
+		if (keylen % prf->blocksize)
+			keylen += prf->blocksize - (keylen % prf->blocksize);
+
+		key = malloc(keylen);
+		if (!key) {
+			/* XXX - Notify peer.  */
+			log_error("ike_phase_1_post_exchange_KE_NONCE: "
+			    "malloc (%d) failed", keylen);
+			return -1;
+		}
+		prf->Init(prf->prfctx);
+		prf->Update(prf->prfctx, (unsigned char *) "\0", 1);
+		prf->Final(key, prf->prfctx);
+
+		for (len = prf->blocksize, p = key; len < exchange->key_length;
+		     len += prf->blocksize, p += prf->blocksize) {
+			prf->Init(prf->prfctx);
+			prf->Update(prf->prfctx, p, prf->blocksize);
+			prf->Final(p + prf->blocksize, prf->prfctx);
+		}
+		prf_free(prf);
+
+		/* Setup our keystate using the derived encryption key.  */
+		exchange->keystate = crypto_init(exchange->crypto, key,
+		    exchange->key_length, &err);
+
+		free(key);
+	} else
+		/* Setup our keystate using the raw skeyid_e.  */
+		exchange->keystate = crypto_init(exchange->crypto,
+		    ie->skeyid_e, exchange->key_length, &err);
+
+	/* Special handling for DES weak keys.  */
+	if (!exchange->keystate && err == EWEAKKEY &&
+	    (exchange->key_length << 1) <= ie->skeyid_len) {
+		log_print("ike_phase_1_post_exchange_KE_NONCE: "
+		    "weak key, trying subseq. skeyid_e");
+		exchange->keystate = crypto_init(exchange->crypto,
+		    ie->skeyid_e + exchange->key_length,
+		    exchange->key_length, &err);
+	}
+	if (!exchange->keystate) {
+		log_print("ike_phase_1_post_exchange_KE_NONCE: "
+		    "exchange->crypto->init () failed: %d", err);
+
+		/*
+		 * XXX We really need to know if problems are of transient
+		 * nature or fatal (like failed assertions etc.)
+		 */
+		return -1;
+	}
+	/* Setup IV.  XXX Only for CBC transforms, no?  */
+	hash->Init(hash->ctx);
+	hash->Update(hash->ctx, ie->g_xi, ie->g_x_len);
+	hash->Update(hash->ctx, ie->g_xr, ie->g_x_len);
+	hash->Final(hash->digest, hash->ctx);
+	crypto_init_iv(exchange->keystate, hash->digest,
+	    exchange->crypto->blocksize);
+	return 0;
+}
+
+int
+ike_phase_1_responder_send_ID_AUTH(struct message *msg)
+{
+	if (ike_phase_1_send_ID(msg))
+		return -1;
+
+	return ike_phase_1_send_AUTH(msg);
+}
+
+int
+ike_phase_1_send_ID(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	u_int8_t       *buf;
+	char            header[80];
+	ssize_t         sz;
+	struct sockaddr *src;
+	int             initiator = exchange->initiator;
+	u_int8_t      **id;
+	size_t         *id_len;
+	char           *my_id = 0, *data;
+	u_int8_t        id_type;
+
+	/* Choose the right fields to fill-in.  */
+	id = initiator ? &exchange->id_i : &exchange->id_r;
+	id_len = initiator ? &exchange->id_i_len : &exchange->id_r_len;
+
+	if (exchange->name)
+		my_id = conf_get_str(exchange->name, "ID");
+
+	if (!my_id)
+		my_id = conf_get_str("General", "Default-phase-1-ID");
+
+	msg->transport->vtbl->get_src(msg->transport, &src);
+	sz = my_id ? ipsec_id_size(my_id, &id_type) : sockaddr_addrlen(src);
+	if (sz == -1)
+		return -1;
+
+	sz += ISAKMP_ID_DATA_OFF;
+	buf = malloc(sz);
+	if (!buf) {
+		log_error("ike_phase_1_send_ID: malloc (%lu) failed",
+			  (unsigned long) sz);
+		return -1;
+	}
+	SET_IPSEC_ID_PROTO(buf + ISAKMP_ID_DOI_DATA_OFF, 0);
+	SET_IPSEC_ID_PORT(buf + ISAKMP_ID_DOI_DATA_OFF, 0);
+	if (my_id) {
+		SET_ISAKMP_ID_TYPE(buf, id_type);
+		switch (id_type) {
+		case IPSEC_ID_IPV4_ADDR:
+		case IPSEC_ID_IPV6_ADDR:
+			/* Already in network byteorder.  */
+			memcpy(buf + ISAKMP_ID_DATA_OFF,
+			    sockaddr_addrdata(src), sockaddr_addrlen(src));
+			break;
+
+		case IPSEC_ID_IPV4_ADDR_SUBNET:
+		case IPSEC_ID_IPV6_ADDR_SUBNET:
+			/* Network */
+			data = conf_get_str(my_id, "Network");
+			if (!data) {
+				log_print("ike_phase_1_send_ID: section %s "
+				    "has no \"Network\" tag", my_id);
+				return -1;
+			}
+			if (text2sockaddr(data, NULL, &src)) {
+				log_error("ike_phase_1_send_ID: "
+				    "text2sockaddr() failed");
+				return -1;
+			}
+			memcpy(buf + ISAKMP_ID_DATA_OFF,
+			    sockaddr_addrdata(src), sockaddr_addrlen(src));
+			free(src);
+			/* Netmask */
+			data = conf_get_str(my_id, "Netmask");
+			if (!data) {
+				log_print("ike_phase_1_send_ID: section %s "
+				    "has no \"Netmask\" tag", my_id);
+				return -1;
+			}
+			if (text2sockaddr(data, NULL, &src)) {
+				log_error("ike_phase_1_send_ID: "
+				    "text2sockaddr() failed");
+				return -1;
+			}
+			memcpy(buf + ISAKMP_ID_DATA_OFF +
+			    sockaddr_addrlen(src), sockaddr_addrdata(src),
+			    sockaddr_addrlen(src));
+			free(src);
+			break;
+
+		case IPSEC_ID_FQDN:
+		case IPSEC_ID_USER_FQDN:
+		case IPSEC_ID_KEY_ID:
+			data = conf_get_str(my_id, "Name");
+			if (!data) {
+				log_print("ike_phase_1_send_ID: section %s "
+				    "has no \"Name\" tag", my_id);
+				return -1;
+			}
+			memcpy(buf + ISAKMP_ID_DATA_OFF, data,
+			    sz - ISAKMP_ID_DATA_OFF);
+			break;
+
+		default:
+			log_print("ike_phase_1_send_ID: "
+			    "unsupported ID type %d", id_type);
+			free(buf);
+			return -1;
+		}
+	} else {
+		switch (src->sa_family) {
+		case AF_INET:
+			SET_ISAKMP_ID_TYPE(buf, IPSEC_ID_IPV4_ADDR);
+			break;
+		case AF_INET6:
+			SET_ISAKMP_ID_TYPE(buf, IPSEC_ID_IPV6_ADDR);
+			break;
+		}
+		/* Already in network byteorder.  */
+		memcpy(buf + ISAKMP_ID_DATA_OFF, sockaddr_addrdata(src),
+		    sockaddr_addrlen(src));
+	}
+
+	if (message_add_payload(msg, ISAKMP_PAYLOAD_ID, buf, sz, 1)) {
+		free(buf);
+		return -1;
+	}
+	*id_len = sz - ISAKMP_GEN_SZ;
+	*id = malloc(*id_len);
+	if (!*id) {
+		log_error("ike_phase_1_send_ID: malloc (%lu) failed",
+		    (unsigned long) *id_len);
+		return -1;
+	}
+	memcpy(*id, buf + ISAKMP_GEN_SZ, *id_len);
+	snprintf(header, sizeof header, "ike_phase_1_send_ID: %s",
+	    constant_name(ipsec_id_cst, GET_ISAKMP_ID_TYPE(buf)));
+	LOG_DBG_BUF((LOG_NEGOTIATION, 40, header, buf + ISAKMP_ID_DATA_OFF,
+	    sz - ISAKMP_ID_DATA_OFF));
+	return 0;
+}
+
+int
+ike_phase_1_send_AUTH(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+
+	if (ie->ike_auth->encode_hash(msg)) {
+		/* XXX Log? */
+		return -1;
+	}
+	/*
+	 * XXX Many people say the COMMIT flag is just junk, especially in
+	 * Phase 1.
+	 */
+#ifdef notyet
+	if ((exchange->flags & EXCHANGE_FLAG_COMMITTED) == 0)
+		exchange->flags |= EXCHANGE_FLAG_I_COMMITTED;
+#endif
+
+	return 0;
+}
+
+/* Receive ID and HASH and check that the exchange has been consistent.  */
+int
+ike_phase_1_recv_ID_AUTH(struct message *msg)
+{
+	if (ike_phase_1_recv_ID(msg))
+		return -1;
+
+	return ike_phase_1_recv_AUTH(msg);
+}
+
+/* Receive ID.  */
+int
+ike_phase_1_recv_ID(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct payload *payload;
+	char            header[80], *rs = 0, *rid = 0, *p;
+	int             initiator = exchange->initiator;
+	u_int8_t      **id, id_type;
+	size_t         *id_len;
+	ssize_t         sz;
+	struct sockaddr *sa;
+
+	payload = payload_first(msg, ISAKMP_PAYLOAD_ID);
+
+	if (exchange->name)
+		rs = conf_get_str(exchange->name, "Remote-ID");
+
+	if (rs) {
+		sz = ipsec_id_size(rs, &id_type);
+		if (sz == -1) {
+			log_print("ike_phase_1_recv_ID: could not handle "
+			    "specified Remote-ID [%s]", rs);
+			return -1;
+		}
+		rid = malloc(sz);
+		if (!rid) {
+			log_error("ike_phase_1_recv_ID: malloc (%lu) failed",
+			    (unsigned long) sz);
+			return -1;
+		}
+		switch (id_type) {
+		case IPSEC_ID_IPV4_ADDR:
+		case IPSEC_ID_IPV6_ADDR:
+			p = conf_get_str(rs, "Address");
+			if (!p) {
+				log_print("ike_phase_1_recv_ID: failed to get "
+				    "Address in Remote-ID section [%s]", rs);
+				free(rid);
+				return -1;
+			}
+			if (text2sockaddr(p, 0, &sa) == -1) {
+				log_print("ike_phase_1_recv_ID: "
+				    "failed to parse address %s", p);
+				free(rid);
+				return -1;
+			}
+			if ((id_type == IPSEC_ID_IPV4_ADDR &&
+			    sa->sa_family != AF_INET) ||
+			    (id_type == IPSEC_ID_IPV6_ADDR &&
+			    sa->sa_family != AF_INET6)) {
+				log_print("ike_phase_1_recv_ID: "
+				    "address %s not of expected family", p);
+				free(rid);
+				free(sa);
+				return -1;
+			}
+			memcpy(rid, sockaddr_addrdata(sa),
+			    sockaddr_addrlen(sa));
+			free(sa);
+			break;
+
+		case IPSEC_ID_FQDN:
+		case IPSEC_ID_USER_FQDN:
+		case IPSEC_ID_KEY_ID:
+			p = conf_get_str(rs, "Name");
+			if (!p) {
+				log_print("ike_phase_1_recv_ID: failed to "
+				    "get Name in Remote-ID section [%s]", rs);
+				free(rid);
+				return -1;
+			}
+			memcpy(rid, p, sz);
+			break;
+
+		default:
+			log_print("ike_phase_1_recv_ID: "
+			    "unsupported ID type %d", id_type);
+			free(rid);
+			return -1;
+		}
+
+		/* Compare expected/desired and received remote ID */
+		if (bcmp(rid, payload->p + ISAKMP_ID_DATA_OFF, sz)) {
+			log_print("ike_phase_1_recv_ID: "
+			    "received remote ID other than expected %s - %s", p, payload->p);
+			free(rid);
+			return -1;
+		}
+		free(rid);
+	}
+	/* Choose the right fields to fill in */
+	id = initiator ? &exchange->id_r : &exchange->id_i;
+	id_len = initiator ? &exchange->id_r_len : &exchange->id_i_len;
+
+	*id_len = GET_ISAKMP_GEN_LENGTH(payload->p) - ISAKMP_GEN_SZ;
+	*id = malloc(*id_len);
+	if (!*id) {
+		log_error("ike_phase_1_recv_ID: malloc (%lu) failed",
+		    (unsigned long) *id_len);
+		return -1;
+	}
+	memcpy(*id, payload->p + ISAKMP_GEN_SZ, *id_len);
+	snprintf(header, sizeof header, "ike_phase_1_recv_ID: %s",
+	    constant_name(ipsec_id_cst, GET_ISAKMP_ID_TYPE(payload->p)));
+	LOG_DBG_BUF((LOG_NEGOTIATION, 40, header,
+	    payload->p + ISAKMP_ID_DATA_OFF,
+	    *id_len + ISAKMP_GEN_SZ - ISAKMP_ID_DATA_OFF));
+	payload->flags |= PL_MARK;
+	return 0;
+}
+
+/* Receive HASH and check that the exchange has been consistent.  */
+int
+ike_phase_1_recv_AUTH(struct message *msg)
+{
+	struct exchange *exchange = msg->exchange;
+	struct ipsec_exch *ie = exchange->data;
+	struct prf     *prf;
+	struct hash    *hash = ie->hash;
+	char            header[80];
+	size_t          hashsize = hash->hashsize;
+	int             initiator = exchange->initiator;
+	u_int8_t      **hash_p, *id;
+	size_t          id_len;
+
+	/* Choose the right fields to fill in */
+	hash_p = initiator ? &ie->hash_r : &ie->hash_i;
+	id = initiator ? exchange->id_r : exchange->id_i;
+	id_len = initiator ? exchange->id_r_len : exchange->id_i_len;
+
+	/* The decoded hash will be in ie->hash_r or ie->hash_i */
+	if (ie->ike_auth->decode_hash(msg)) {
+		message_drop(msg, ISAKMP_NOTIFY_INVALID_ID_INFORMATION, 0, 1,
+		    0);
+		return -1;
+	}
+	/* Allocate the prf and start calculating his HASH.  */
+	prf = prf_alloc(ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len);
+	if (!prf) {
+		/* XXX Log?  */
+		return -1;
+	}
+	prf->Init(prf->prfctx);
+	prf->Update(prf->prfctx, initiator ? ie->g_xr : ie->g_xi, ie->g_x_len);
+	prf->Update(prf->prfctx, initiator ? ie->g_xi : ie->g_xr, ie->g_x_len);
+	prf->Update(prf->prfctx, exchange->cookies +
+	    (initiator ? ISAKMP_HDR_RCOOKIE_OFF : ISAKMP_HDR_ICOOKIE_OFF),
+	    ISAKMP_HDR_ICOOKIE_LEN);
+	prf->Update(prf->prfctx, exchange->cookies +
+	    (initiator ? ISAKMP_HDR_ICOOKIE_OFF : ISAKMP_HDR_RCOOKIE_OFF),
+	    ISAKMP_HDR_ICOOKIE_LEN);
+	prf->Update(prf->prfctx, ie->sa_i_b, ie->sa_i_b_len);
+	prf->Update(prf->prfctx, id, id_len);
+	prf->Final(hash->digest, prf->prfctx);
+	prf_free(prf);
+	snprintf(header, sizeof header, "ike_phase_1_recv_AUTH: "
+	    "computed HASH_%c", initiator ? 'R' : 'I');
+	LOG_DBG_BUF((LOG_NEGOTIATION, 80, header, hash->digest, hashsize));
+
+	/* Check that the hash we got matches the one we computed.  */
+	if (memcmp(*hash_p, hash->digest, hashsize) != 0) {
+		/* XXX Log?  */
+		return -1;
+	}
+
+	/* Mark message as authenticated. */
+	msg->flags |= MSG_AUTHENTICATED;
+
+	return 0;
+}
+
+struct attr_node {
+	LIST_ENTRY(attr_node) link;
+	u_int16_t       type;
+};
+
+struct validation_state {
+	struct conf_list_node *xf;
+	LIST_HEAD(attr_head, attr_node) attrs;
+	char           *life;
+};
+
+/* Validate a proposal inside SA according to EXCHANGE's policy.  */
+static int
+ike_phase_1_validate_prop(struct exchange *exchange, struct sa *sa,
+    struct sa *isakmp_sa)
+{
+	struct conf_list *conf, *tags;
+	struct conf_list_node *xf, *tag;
+	struct proto   *proto;
+	struct validation_state vs;
+	struct attr_node *node, *next_node;
+
+	/* Get the list of transforms.  */
+	conf = conf_get_list(exchange->policy, "Transforms");
+	if (!conf)
+		return 0;
+
+	for (xf = TAILQ_FIRST(&conf->fields); xf; xf = TAILQ_NEXT(xf, link)) {
+		for (proto = TAILQ_FIRST(&sa->protos); proto;
+		    proto = TAILQ_NEXT(proto, link)) {
+			/* Mark all attributes in our policy as unseen.  */
+			LIST_INIT(&vs.attrs);
+			vs.xf = xf;
+			vs.life = 0;
+			if (attribute_map(proto->chosen->p +
+			    ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+			    GET_ISAKMP_GEN_LENGTH(proto->chosen->p) -
+			    ISAKMP_TRANSFORM_SA_ATTRS_OFF,
+			    attribute_unacceptable, &vs))
+				goto try_next;
+
+			/* Sweep over unseen tags in this section.  */
+			tags = conf_get_tag_list(xf->field);
+			if (tags) {
+				for (tag = TAILQ_FIRST(&tags->fields); tag;
+				    tag = TAILQ_NEXT(tag, link))
+					/*
+					 * XXX Should we care about attributes
+					 * we have, they do not provide?
+					 */
+					for (node = LIST_FIRST(&vs.attrs);
+					     node; node = next_node) {
+						next_node =
+						    LIST_NEXT(node, link);
+						if (node->type ==
+						    constant_value(ike_attr_cst,
+						    tag->field)) {
+							LIST_REMOVE(node, link);
+							free(node);
+						}
+					}
+				conf_free_list(tags);
+			}
+			/* Are there leftover tags in this section?  */
+			node = LIST_FIRST(&vs.attrs);
+			if (node)
+				goto try_next;
+		}
+
+		/* All protocols were OK, we succeeded.  */
+		LOG_DBG((LOG_NEGOTIATION, 20, "ike_phase_1_validate_prop: "
+		    "success"));
+		conf_free_list(conf);
+		if (vs.life)
+			free(vs.life);
+		return 1;
+
+try_next:
+		/* Are there leftover tags in this section?  */
+		node = LIST_FIRST(&vs.attrs);
+		while (node) {
+			LIST_REMOVE(node, link);
+			free(node);
+			node = LIST_FIRST(&vs.attrs);
+		}
+		if (vs.life)
+			free(vs.life);
+	}
+
+	LOG_DBG((LOG_NEGOTIATION, 20, "ike_phase_1_validate_prop: failure"));
+	conf_free_list(conf);
+	return 0;
+}
+
+/*
+ * Look at the attribute of type TYPE, located at VALUE for LEN bytes forward.
+ * The VVS argument holds a validation state kept across invocations.
+ * If the attribute is unacceptable to use, return non-zero, otherwise zero.
+ */
+static int
+attribute_unacceptable(u_int16_t type, u_int8_t *value, u_int16_t len,
+    void *vvs)
+{
+	struct validation_state *vs = vvs;
+	struct conf_list *life_conf;
+	struct conf_list_node *xf = vs->xf, *life;
+	char           *tag = constant_lookup(ike_attr_cst, type);
+	char           *str;
+	struct constant_map *map;
+	struct attr_node *node;
+	int             rv;
+
+	if (!tag) {
+		LOG_DBG((LOG_NEGOTIATION, 60, "attribute_unacceptable: "
+		    "attribute type %d not known", type));
+		return 1;
+	}
+	switch (type) {
+	case IKE_ATTR_ENCRYPTION_ALGORITHM:
+	case IKE_ATTR_HASH_ALGORITHM:
+	case IKE_ATTR_AUTHENTICATION_METHOD:
+	case IKE_ATTR_GROUP_DESCRIPTION:
+	case IKE_ATTR_GROUP_TYPE:
+	case IKE_ATTR_PRF:
+		str = conf_get_str(xf->field, tag);
+		if (!str) {
+			/* This attribute does not exist in this policy.  */
+			LOG_DBG((LOG_NEGOTIATION, 70,
+			    "attribute_unacceptable: attr %s does not exist "
+			    "in %s", tag, xf->field));
+			return 1;
+		}
+		map = constant_link_lookup(ike_attr_cst, type);
+		if (!map)
+			return 1;
+
+		if ((constant_value(map, str) == decode_16(value)) ||
+		    (!strcmp(str, "ANY"))) {
+			/* Mark this attribute as seen.  */
+			node = malloc(sizeof *node);
+			if (!node) {
+				log_error("attribute_unacceptable: "
+				    "malloc (%lu) failed",
+				    (unsigned long) sizeof *node);
+				return 1;
+			}
+			node->type = type;
+			LIST_INSERT_HEAD(&vs->attrs, node, link);
+			return 0;
+		}
+		LOG_DBG((LOG_NEGOTIATION, 70,
+		    "attribute_unacceptable: %s: got %s, expected %s", tag,
+		    constant_name(map, decode_16(value)), str));
+		return 1;
+
+	case IKE_ATTR_GROUP_PRIME:
+	case IKE_ATTR_GROUP_GENERATOR_1:
+	case IKE_ATTR_GROUP_GENERATOR_2:
+	case IKE_ATTR_GROUP_CURVE_A:
+	case IKE_ATTR_GROUP_CURVE_B:
+		/* XXX Bignums not handled yet.  */
+		return 1;
+
+	case IKE_ATTR_LIFE_TYPE:
+	case IKE_ATTR_LIFE_DURATION:
+		life_conf = conf_get_list(xf->field, "Life");
+		if (life_conf &&
+		    !strcmp(conf_get_str(xf->field, "Life"), "ANY"))
+			return 0;
+
+		rv = 1;
+		if (!life_conf) {
+			/* Life attributes given, but not in our policy.  */
+			LOG_DBG((LOG_NEGOTIATION, 70,
+			    "attribute_unacceptable: received unexpected life "
+			    "attribute"));
+			return 1;
+		}
+		/*
+		 * Each lifetime type must match, otherwise we turn the
+		 * proposal down. In order to do this we need to find the
+		 * specific section of our policy's "Life" list and match
+		 * its duration.
+		 */
+		switch (type) {
+		case IKE_ATTR_LIFE_TYPE:
+			for (life = TAILQ_FIRST(&life_conf->fields); life;
+			    life = TAILQ_NEXT(life, link)) {
+				str = conf_get_str(life->field, "LIFE_TYPE");
+				if (!str) {
+					LOG_DBG((LOG_NEGOTIATION, 70,
+					    "attribute_unacceptable: "
+					    "section [%s] has no LIFE_TYPE",
+					    life->field));
+					continue;
+				}
+
+				/*
+				 * If this is the type we are looking at,
+				 * to save a pointer this section in vs->life.
+				 */
+				if (constant_value(ike_duration_cst, str) ==
+				    decode_16(value)) {
+					vs->life = strdup(life->field);
+					rv = 0;
+					goto bail_out;
+				}
+			}
+			LOG_DBG((LOG_NEGOTIATION, 70, "attribute_unacceptable:"
+			    " unrecognized LIFE_TYPE %d", decode_16(value)));
+			vs->life = 0;
+			break;
+
+		case IKE_ATTR_LIFE_DURATION:
+			if (!vs->life) {
+				LOG_DBG((LOG_NEGOTIATION, 70,
+				    "attribute_unacceptable: "
+				    "LIFE_DURATION without LIFE_TYPE"));
+				rv = 1;
+				goto bail_out;
+			}
+			str = conf_get_str(vs->life, "LIFE_DURATION");
+			if (str) {
+				if (!strcmp(str, "ANY"))
+					rv = 0;
+				else
+					rv = !conf_match_num(vs->life,
+					    "LIFE_DURATION",
+					    len == 4 ? decode_32(value) :
+					    decode_16(value));
+			} else {
+				LOG_DBG((LOG_NEGOTIATION, 70,
+				    "attribute_unacceptable: section [%s] has "
+				    "no LIFE_DURATION", vs->life));
+				rv = 1;
+			}
+
+			free(vs->life);
+			vs->life = 0;
+			break;
+		}
+
+bail_out:
+		conf_free_list(life_conf);
+		return rv;
+
+	case IKE_ATTR_KEY_LENGTH:
+	case IKE_ATTR_FIELD_SIZE:
+	case IKE_ATTR_GROUP_ORDER:
+		if (conf_match_num(xf->field, tag, decode_16(value))) {
+			/* Mark this attribute as seen.  */
+			node = malloc(sizeof *node);
+			if (!node) {
+				log_error("attribute_unacceptable: "
+				    "malloc (%lu) failed",
+				    (unsigned long) sizeof *node);
+				return 1;
+			}
+			node->type = type;
+			LIST_INSERT_HEAD(&vs->attrs, node, link);
+			return 0;
+		}
+		return 1;
+	}
+	return 1;
+}