[svn-upgrade] Integrating new upstream version, strongswan (4.4.0)

1 files changed, 1351 insertions, 0 deletions

diff --git a/src/libcharon/sa/tasks/child_create.c b/src/libcharon/sa/tasks/child_create.c
new file mode 100644
index 000000000..bea4f73d5
--- /dev/null
+++ b/src/libcharon/sa/tasks/child_create.c
@@ -0,0 +1,1351 @@
+/*
+ * Copyright (C) 2008 Tobias Brunner
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "child_create.h"
+
+#include <daemon.h>
+#include <crypto/diffie_hellman.h>
+#include <credentials/certificates/x509.h>
+#include <encoding/payloads/sa_payload.h>
+#include <encoding/payloads/ke_payload.h>
+#include <encoding/payloads/ts_payload.h>
+#include <encoding/payloads/nonce_payload.h>
+#include <encoding/payloads/notify_payload.h>
+#include <processing/jobs/delete_ike_sa_job.h>
+#include <processing/jobs/inactivity_job.h>
+
+
+typedef struct private_child_create_t private_child_create_t;
+
+/**
+ * Private members of a child_create_t task.
+ */
+struct private_child_create_t {
+
+	/**
+	 * Public methods and task_t interface.
+	 */
+	child_create_t public;
+
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+
+	/**
+	 * Are we the initiator?
+	 */
+	bool initiator;
+
+	/**
+	 * nonce chosen by us
+	 */
+	chunk_t my_nonce;
+
+	/**
+	 * nonce chosen by peer
+	 */
+	chunk_t other_nonce;
+
+	/**
+	 * config to create the CHILD_SA from
+	 */
+	child_cfg_t *config;
+
+	/**
+	 * list of proposal candidates
+	 */
+	linked_list_t *proposals;
+
+	/**
+	 * selected proposal to use for CHILD_SA
+	 */
+	proposal_t *proposal;
+
+	/**
+	 * traffic selectors for initiators side
+	 */
+	linked_list_t *tsi;
+
+	/**
+	 * traffic selectors for responders side
+	 */
+	linked_list_t *tsr;
+
+	/**
+	 * source of triggering packet
+	 */
+	traffic_selector_t *packet_tsi;
+
+	/**
+	 * destination of triggering packet
+	 */
+	traffic_selector_t *packet_tsr;
+
+	/**
+	 * optional diffie hellman exchange
+	 */
+	diffie_hellman_t *dh;
+
+	/**
+	 * group used for DH exchange
+	 */
+	diffie_hellman_group_t dh_group;
+
+	/**
+	 * IKE_SAs keymat
+	 */
+	keymat_t *keymat;
+
+	/**
+	 * mode the new CHILD_SA uses (transport/tunnel/beet)
+	 */
+	ipsec_mode_t mode;
+
+	/**
+	 * IPComp transform to use
+	 */
+	ipcomp_transform_t ipcomp;
+
+	/**
+	 * IPComp transform proposed or accepted by the other peer
+	 */
+	ipcomp_transform_t ipcomp_received;
+
+	/**
+	 * Own allocated SPI
+	 */
+	u_int32_t my_spi;
+
+	/**
+	 * SPI received in proposal
+	 */
+	u_int32_t other_spi;
+
+	/**
+	 * Own allocated Compression Parameter Index (CPI)
+	 */
+	u_int16_t my_cpi;
+
+	/**
+	 * Other Compression Parameter Index (CPI), received via IPCOMP_SUPPORTED
+	 */
+	u_int16_t other_cpi;
+
+	/**
+	 * reqid to use if we are rekeying
+	 */
+	u_int32_t reqid;
+
+	/**
+	 * CHILD_SA which gets established
+	 */
+	child_sa_t *child_sa;
+
+	/**
+	 * successfully established the CHILD?
+	 */
+	bool established;
+
+	/**
+	 * whether the CHILD_SA rekeys an existing one
+	 */
+	bool rekey;
+};
+
+/**
+ * get the nonce from a message
+ */
+static status_t get_nonce(message_t *message, chunk_t *nonce)
+{
+	nonce_payload_t *payload;
+
+	payload = (nonce_payload_t*)message->get_payload(message, NONCE);
+	if (payload == NULL)
+	{
+		return FAILED;
+	}
+	*nonce = payload->get_nonce(payload);
+	return NEED_MORE;
+}
+
+/**
+ * generate a new nonce to include in a CREATE_CHILD_SA message
+ */
+static status_t generate_nonce(chunk_t *nonce)
+{
+	rng_t *rng;
+
+	rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
+	if (!rng)
+	{
+		DBG1(DBG_IKE, "error generating nonce value, no RNG found");
+		return FAILED;
+	}
+	rng->allocate_bytes(rng, NONCE_SIZE, nonce);
+	rng->destroy(rng);
+	return SUCCESS;
+}
+
+/**
+ * Check a list of traffic selectors if any selector belongs to host
+ */
+static bool ts_list_is_host(linked_list_t *list, host_t *host)
+{
+	traffic_selector_t *ts;
+	bool is_host = TRUE;
+	iterator_t *iterator = list->create_iterator(list, TRUE);
+
+	while (is_host && iterator->iterate(iterator, (void**)&ts))
+	{
+		is_host = is_host && ts->is_host(ts, host);
+	}
+	iterator->destroy(iterator);
+	return is_host;
+}
+
+/**
+ * Allocate SPIs and update proposals
+ */
+static bool allocate_spi(private_child_create_t *this)
+{
+	enumerator_t *enumerator;
+	proposal_t *proposal;
+
+	/* TODO: allocate additional SPI for AH if we have such proposals */
+	this->my_spi = this->child_sa->alloc_spi(this->child_sa, PROTO_ESP);
+	if (this->my_spi)
+	{
+		if (this->initiator)
+		{
+			enumerator = this->proposals->create_enumerator(this->proposals);
+			while (enumerator->enumerate(enumerator, &proposal))
+			{
+				proposal->set_spi(proposal, this->my_spi);
+			}
+			enumerator->destroy(enumerator);
+		}
+		else
+		{
+			this->proposal->set_spi(this->proposal, this->my_spi);
+		}
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Schedule inactivity timeout for CHILD_SA with reqid, if enabled
+ */
+static void schedule_inactivity_timeout(private_child_create_t *this)
+{
+	u_int32_t timeout;
+	bool close_ike;
+
+	timeout = this->config->get_inactivity(this->config);
+	if (timeout)
+	{
+		close_ike = lib->settings->get_bool(lib->settings,
+										"charon.inactivity_close_ike", FALSE);
+		charon->scheduler->schedule_job(charon->scheduler, (job_t*)
+				inactivity_job_create(this->child_sa->get_reqid(this->child_sa),
+									  timeout, close_ike), timeout);
+	}
+}
+
+/**
+ * Install a CHILD_SA for usage, return value:
+ * - FAILED: no acceptable proposal
+ * - INVALID_ARG: diffie hellman group inacceptable
+ * - NOT_FOUND: TS inacceptable
+ */
+static status_t select_and_install(private_child_create_t *this, bool no_dh)
+{
+	status_t status, status_i, status_o;
+	chunk_t nonce_i, nonce_r;
+	chunk_t encr_i = chunk_empty, encr_r = chunk_empty;
+	chunk_t integ_i = chunk_empty, integ_r = chunk_empty;
+	linked_list_t *my_ts, *other_ts;
+	host_t *me, *other, *other_vip, *my_vip;
+	bool private;
+
+	if (this->proposals == NULL)
+	{
+		DBG1(DBG_IKE, "SA payload missing in message");
+		return FAILED;
+	}
+	if (this->tsi == NULL || this->tsr == NULL)
+	{
+		DBG1(DBG_IKE, "TS payloads missing in message");
+		return NOT_FOUND;
+	}
+
+	me = this->ike_sa->get_my_host(this->ike_sa);
+	other = this->ike_sa->get_other_host(this->ike_sa);
+	my_vip = this->ike_sa->get_virtual_ip(this->ike_sa, TRUE);
+	other_vip = this->ike_sa->get_virtual_ip(this->ike_sa, FALSE);
+
+	private = this->ike_sa->supports_extension(this->ike_sa, EXT_STRONGSWAN);
+	this->proposal = this->config->select_proposal(this->config,
+											this->proposals, no_dh, private);
+	if (this->proposal == NULL)
+	{
+		DBG1(DBG_IKE, "no acceptable proposal found");
+		return FAILED;
+	}
+	this->other_spi = this->proposal->get_spi(this->proposal);
+
+	if (!this->initiator && !allocate_spi(this))
+	{	/* responder has no SPI allocated yet */
+		DBG1(DBG_IKE, "allocating SPI failed");
+		return FAILED;
+	}
+	this->child_sa->set_proposal(this->child_sa, this->proposal);
+
+	if (!this->proposal->has_dh_group(this->proposal, this->dh_group))
+	{
+		u_int16_t group;
+
+		if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
+										  &group, NULL))
+		{
+			DBG1(DBG_IKE, "DH group %N inacceptable, requesting %N",
+				 diffie_hellman_group_names, this->dh_group,
+				 diffie_hellman_group_names, group);
+			this->dh_group = group;
+			return INVALID_ARG;
+		}
+		/* the selected proposal does not use a DH group */
+		DBG1(DBG_IKE, "ignoring KE exchange, agreed on a non-PFS proposal");
+		DESTROY_IF(this->dh);
+		this->dh = NULL;
+		this->dh_group = MODP_NONE;
+	}
+
+	if (my_vip == NULL)
+	{
+		my_vip = me;
+	}
+	if (other_vip == NULL)
+	{
+		other_vip = other;
+	}
+
+	if (this->initiator)
+	{
+		nonce_i = this->my_nonce;
+		nonce_r = this->other_nonce;
+		my_ts = this->tsi;
+		other_ts = this->tsr;
+	}
+	else
+	{
+		nonce_r = this->my_nonce;
+		nonce_i = this->other_nonce;
+		my_ts = this->tsr;
+		other_ts = this->tsi;
+	}
+	my_ts = this->config->get_traffic_selectors(this->config, TRUE, my_ts,
+												my_vip);
+	other_ts = this->config->get_traffic_selectors(this->config, FALSE, other_ts,
+												   other_vip);
+
+	if (my_ts->get_count(my_ts) == 0 || other_ts->get_count(other_ts) == 0)
+	{
+		my_ts->destroy_offset(my_ts, offsetof(traffic_selector_t, destroy));
+		other_ts->destroy_offset(other_ts, offsetof(traffic_selector_t, destroy));
+		DBG1(DBG_IKE, "no acceptable traffic selectors found");
+		return NOT_FOUND;
+	}
+
+	this->tsr->destroy_offset(this->tsr, offsetof(traffic_selector_t, destroy));
+	this->tsi->destroy_offset(this->tsi, offsetof(traffic_selector_t, destroy));
+	if (this->initiator)
+	{
+		this->tsi = my_ts;
+		this->tsr = other_ts;
+	}
+	else
+	{
+		this->tsr = my_ts;
+		this->tsi = other_ts;
+	}
+
+	if (!this->initiator)
+	{
+		/* check if requested mode is acceptable, downgrade if required */
+		switch (this->mode)
+		{
+			case MODE_TRANSPORT:
+				if (!this->config->use_proxy_mode(this->config) &&
+					   (!ts_list_is_host(this->tsi, other) ||
+						!ts_list_is_host(this->tsr, me))
+				   )
+				{
+					this->mode = MODE_TUNNEL;
+					DBG1(DBG_IKE, "not using transport mode, not host-to-host");
+				}
+				else if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY))
+				{
+					this->mode = MODE_TUNNEL;
+					DBG1(DBG_IKE, "not using transport mode, connection NATed");
+				}
+				break;
+			case MODE_BEET:
+				if (!ts_list_is_host(this->tsi, NULL) ||
+					!ts_list_is_host(this->tsr, NULL))
+				{
+					this->mode = MODE_TUNNEL;
+					DBG1(DBG_IKE, "not using BEET mode, not host-to-host");
+				}
+				break;
+			default:
+				break;
+		}
+	}
+
+	/* check for any certificate-based IP address block constraints */
+	if (this->mode == MODE_BEET || this->mode == MODE_TUNNEL)
+	{
+		auth_cfg_t *auth;
+		enumerator_t *auth_enum;
+		certificate_t *cert = NULL;
+
+		auth_enum = this->ike_sa->create_auth_cfg_enumerator(this->ike_sa, FALSE);
+		while (auth_enum->enumerate(auth_enum, &auth))
+		{
+			cert = auth->get(auth, AUTH_HELPER_SUBJECT_CERT);
+			if (cert)
+			{
+				break;
+			}
+		}
+		auth_enum->destroy(auth_enum);
+
+		if (cert && cert->get_type(cert) == CERT_X509)
+		{
+			x509_t *x509 = (x509_t*)cert;
+
+			if (x509->get_flags(x509) & X509_IP_ADDR_BLOCKS)
+			{
+				enumerator_t *enumerator, *block_enum;
+				traffic_selector_t *ts, *block_ts;
+
+				DBG1(DBG_IKE, "checking certificate-based traffic selector "
+							  "constraints [RFC 3779]");
+				enumerator = other_ts->create_enumerator(other_ts);
+				while (enumerator->enumerate(enumerator, &ts))
+				{
+					bool contained = FALSE;
+
+					block_enum = x509->create_ipAddrBlock_enumerator(x509);
+					while (block_enum->enumerate(block_enum, &block_ts))
+					{
+						if (ts->is_contained_in(ts, block_ts))
+						{
+							DBG1(DBG_IKE, "  TS %R is contained in address block"
+										  " constraint %R", ts, block_ts);
+							contained = TRUE;
+							break;
+						}
+					}
+					block_enum->destroy(block_enum);
+
+					if (!contained)
+					{
+						DBG1(DBG_IKE, "  TS %R is not contained in any"
+									  " address block constraint", ts);
+						enumerator->destroy(enumerator);
+						return FAILED;
+					}
+				}
+				enumerator->destroy(enumerator);
+			}
+		}
+	}
+
+	this->child_sa->set_state(this->child_sa, CHILD_INSTALLING);
+	this->child_sa->set_ipcomp(this->child_sa, this->ipcomp);
+	this->child_sa->set_mode(this->child_sa, this->mode);
+	this->child_sa->set_protocol(this->child_sa,
+								 this->proposal->get_protocol(this->proposal));
+
+	if (this->my_cpi == 0 || this->other_cpi == 0 || this->ipcomp == IPCOMP_NONE)
+	{
+		this->my_cpi = this->other_cpi = 0;
+		this->ipcomp = IPCOMP_NONE;
+	}
+	status_i = status_o = FAILED;
+	if (this->keymat->derive_child_keys(this->keymat, this->proposal,
+			this->dh, nonce_i, nonce_r, &encr_i, &integ_i, &encr_r, &integ_r))
+	{
+		if (this->initiator)
+		{
+			status_i = this->child_sa->install(this->child_sa, encr_r, integ_r,
+					this->my_spi, this->my_cpi, TRUE, my_ts, other_ts);
+			status_o = this->child_sa->install(this->child_sa, encr_i, integ_i,
+					this->other_spi, this->other_cpi, FALSE, my_ts, other_ts);
+		}
+		else
+		{
+			status_i = this->child_sa->install(this->child_sa, encr_i, integ_i,
+					this->my_spi, this->my_cpi, TRUE, my_ts, other_ts);
+			status_o = this->child_sa->install(this->child_sa, encr_r, integ_r,
+					this->other_spi, this->other_cpi, FALSE, my_ts, other_ts);
+		}
+	}
+	chunk_clear(&integ_i);
+	chunk_clear(&integ_r);
+	chunk_clear(&encr_i);
+	chunk_clear(&encr_r);
+
+	if (status_i != SUCCESS || status_o != SUCCESS)
+	{
+		DBG1(DBG_IKE, "unable to install %s%s%sIPsec SA (SAD) in kernel",
+			(status_i != SUCCESS) ? "inbound " : "",
+			(status_i != SUCCESS && status_o != SUCCESS) ? "and ": "",
+			(status_o != SUCCESS) ? "outbound " : "");
+		return FAILED;
+	}
+
+	status = this->child_sa->add_policies(this->child_sa, my_ts, other_ts);
+	if (status != SUCCESS)
+	{
+		DBG1(DBG_IKE, "unable to install IPsec policies (SPD) in kernel");
+		return NOT_FOUND;
+	}
+
+	charon->bus->child_keys(charon->bus, this->child_sa, this->dh,
+							nonce_i, nonce_r);
+
+	/* add to IKE_SA, and remove from task */
+	this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
+	this->ike_sa->add_child_sa(this->ike_sa, this->child_sa);
+	this->established = TRUE;
+
+	if (!this->rekey)
+	{	/* a rekeyed SA uses the same reqid, no need for a new job */
+		schedule_inactivity_timeout(this);
+	}
+	return SUCCESS;
+}
+
+/**
+ * build the payloads for the message
+ */
+static void build_payloads(private_child_create_t *this, message_t *message)
+{
+	sa_payload_t *sa_payload;
+	nonce_payload_t *nonce_payload;
+	ke_payload_t *ke_payload;
+	ts_payload_t *ts_payload;
+
+	/* add SA payload */
+	if (this->initiator)
+	{
+		sa_payload = sa_payload_create_from_proposal_list(this->proposals);
+	}
+	else
+	{
+		sa_payload = sa_payload_create_from_proposal(this->proposal);
+	}
+	message->add_payload(message, (payload_t*)sa_payload);
+
+	/* add nonce payload if not in IKE_AUTH */
+	if (message->get_exchange_type(message) == CREATE_CHILD_SA)
+	{
+		nonce_payload = nonce_payload_create();
+		nonce_payload->set_nonce(nonce_payload, this->my_nonce);
+		message->add_payload(message, (payload_t*)nonce_payload);
+	}
+
+	/* diffie hellman exchange, if PFS enabled */
+	if (this->dh)
+	{
+		ke_payload = ke_payload_create_from_diffie_hellman(this->dh);
+		message->add_payload(message, (payload_t*)ke_payload);
+	}
+
+	/* add TSi/TSr payloads */
+	ts_payload = ts_payload_create_from_traffic_selectors(TRUE, this->tsi);
+	message->add_payload(message, (payload_t*)ts_payload);
+	ts_payload = ts_payload_create_from_traffic_selectors(FALSE, this->tsr);
+	message->add_payload(message, (payload_t*)ts_payload);
+
+	/* add a notify if we are not in tunnel mode */
+	switch (this->mode)
+	{
+		case MODE_TRANSPORT:
+			message->add_notify(message, FALSE, USE_TRANSPORT_MODE, chunk_empty);
+			break;
+		case MODE_BEET:
+			message->add_notify(message, FALSE, USE_BEET_MODE, chunk_empty);
+			break;
+		default:
+			break;
+	}
+}
+
+/**
+ * Adds an IPCOMP_SUPPORTED notify to the message, allocating a CPI
+ */
+static void add_ipcomp_notify(private_child_create_t *this,
+								  message_t *message, u_int8_t ipcomp)
+{
+	if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY))
+	{
+		DBG1(DBG_IKE, "IPComp is not supported if either peer is natted, "
+			 "IPComp disabled");
+		return;
+	}
+
+	this->my_cpi = this->child_sa->alloc_cpi(this->child_sa);
+	if (this->my_cpi)
+	{
+		this->ipcomp = ipcomp;
+		message->add_notify(message, FALSE, IPCOMP_SUPPORTED,
+							chunk_cata("cc", chunk_from_thing(this->my_cpi),
+									   chunk_from_thing(ipcomp)));
+	}
+	else
+	{
+		DBG1(DBG_IKE, "unable to allocate a CPI from kernel, IPComp disabled");
+	}
+}
+
+/**
+ * handle a received notify payload
+ */
+static void handle_notify(private_child_create_t *this, notify_payload_t *notify)
+{
+	switch (notify->get_notify_type(notify))
+	{
+		case USE_TRANSPORT_MODE:
+			this->mode = MODE_TRANSPORT;
+			break;
+		case USE_BEET_MODE:
+			if (this->ike_sa->supports_extension(this->ike_sa, EXT_STRONGSWAN))
+			{	/* handle private use notify only if we know its meaning */
+				this->mode = MODE_BEET;
+			}
+			else
+			{
+				DBG1(DBG_IKE, "received a notify strongSwan uses for BEET "
+					 "mode, but peer implementation unknown, skipped");
+			}
+			break;
+		case IPCOMP_SUPPORTED:
+		{
+			ipcomp_transform_t ipcomp;
+			u_int16_t cpi;
+			chunk_t data;
+
+			data = notify->get_notification_data(notify);
+			cpi = *(u_int16_t*)data.ptr;
+			ipcomp = (ipcomp_transform_t)(*(data.ptr + 2));
+			switch (ipcomp)
+			{
+				case IPCOMP_DEFLATE:
+					this->other_cpi = cpi;
+					this->ipcomp_received = ipcomp;
+					break;
+				case IPCOMP_LZS:
+				case IPCOMP_LZJH:
+				default:
+					DBG1(DBG_IKE, "received IPCOMP_SUPPORTED notify with a "
+						 "transform ID we don't support %N",
+						 ipcomp_transform_names, ipcomp);
+					break;
+			}
+		}
+		default:
+			break;
+	}
+}
+
+/**
+ * Read payloads from message
+ */
+static void process_payloads(private_child_create_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	payload_t *payload;
+	sa_payload_t *sa_payload;
+	ke_payload_t *ke_payload;
+	ts_payload_t *ts_payload;
+
+	/* defaults to TUNNEL mode */
+	this->mode = MODE_TUNNEL;
+
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		switch (payload->get_type(payload))
+		{
+			case SECURITY_ASSOCIATION:
+				sa_payload = (sa_payload_t*)payload;
+				this->proposals = sa_payload->get_proposals(sa_payload);
+				break;
+			case KEY_EXCHANGE:
+				ke_payload = (ke_payload_t*)payload;
+				if (!this->initiator)
+				{
+					this->dh_group = ke_payload->get_dh_group_number(ke_payload);
+					this->dh = this->keymat->create_dh(this->keymat, this->dh_group);
+				}
+				if (this->dh)
+				{
+					this->dh->set_other_public_value(this->dh,
+								ke_payload->get_key_exchange_data(ke_payload));
+				}
+				break;
+			case TRAFFIC_SELECTOR_INITIATOR:
+				ts_payload = (ts_payload_t*)payload;
+				this->tsi = ts_payload->get_traffic_selectors(ts_payload);
+				break;
+			case TRAFFIC_SELECTOR_RESPONDER:
+				ts_payload = (ts_payload_t*)payload;
+				this->tsr = ts_payload->get_traffic_selectors(ts_payload);
+				break;
+			case NOTIFY:
+				handle_notify(this, (notify_payload_t*)payload);
+				break;
+			default:
+				break;
+		}
+	}
+	enumerator->destroy(enumerator);
+}
+
+/**
+ * Implementation of task_t.build for initiator
+ */
+static status_t build_i(private_child_create_t *this, message_t *message)
+{
+	host_t *me, *other, *vip;
+	peer_cfg_t *peer_cfg;
+
+	switch (message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+			return get_nonce(message, &this->my_nonce);
+		case CREATE_CHILD_SA:
+			if (generate_nonce(&this->my_nonce) != SUCCESS)
+			{
+				message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN, chunk_empty);
+				return SUCCESS;
+			}
+			if (this->dh_group == MODP_NONE)
+			{
+				this->dh_group = this->config->get_dh_group(this->config);
+			}
+			break;
+		case IKE_AUTH:
+			if (message->get_message_id(message) != 1)
+			{
+				/* send only in the first request, not in subsequent rounds */
+				return NEED_MORE;
+			}
+			break;
+		default:
+			break;
+	}
+
+	if (this->reqid)
+	{
+		DBG0(DBG_IKE, "establishing CHILD_SA %s{%d}",
+			 this->config->get_name(this->config), this->reqid);
+	}
+	else
+	{
+		DBG0(DBG_IKE, "establishing CHILD_SA %s",
+			 this->config->get_name(this->config));
+	}
+
+	/* reuse virtual IP if we already have one */
+	me = this->ike_sa->get_virtual_ip(this->ike_sa, TRUE);
+	if (me == NULL)
+	{
+		me = this->ike_sa->get_my_host(this->ike_sa);
+	}
+	other = this->ike_sa->get_virtual_ip(this->ike_sa, FALSE);
+	if (other == NULL)
+	{
+		other = this->ike_sa->get_other_host(this->ike_sa);
+	}
+
+	/* check if we want a virtual IP, but don't have one */
+	peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
+	vip = peer_cfg->get_virtual_ip(peer_cfg);
+	if (!this->reqid && vip)
+	{
+		/* propose a 0.0.0.0/0 or ::/0 subnet when we use virtual ip */
+		vip = host_create_any(vip->get_family(vip));
+		this->tsi = this->config->get_traffic_selectors(this->config, TRUE,
+														NULL, vip);
+		vip->destroy(vip);
+	}
+	else
+	{	/* but narrow it for host2host / if we already have a vip */
+		this->tsi = this->config->get_traffic_selectors(this->config, TRUE,
+														NULL, me);
+	}
+	this->tsr = this->config->get_traffic_selectors(this->config, FALSE,
+													NULL, other);
+
+	if (this->packet_tsi)
+	{
+		this->tsi->insert_first(this->tsi,
+								this->packet_tsi->clone(this->packet_tsi));
+	}
+	if (this->packet_tsr)
+	{
+		this->tsr->insert_first(this->tsr,
+								this->packet_tsr->clone(this->packet_tsr));
+	}
+	this->proposals = this->config->get_proposals(this->config,
+												  this->dh_group == MODP_NONE);
+	this->mode = this->config->get_mode(this->config);
+	if (this->mode == MODE_TRANSPORT &&
+		this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY))
+	{
+		this->mode = MODE_TUNNEL;
+		DBG1(DBG_IKE, "not using transport mode, connection NATed");
+	}
+
+	this->child_sa = child_sa_create(this->ike_sa->get_my_host(this->ike_sa),
+			this->ike_sa->get_other_host(this->ike_sa), this->config, this->reqid,
+			this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY));
+
+	if (!allocate_spi(this))
+	{
+		DBG1(DBG_IKE, "unable to allocate SPIs from kernel");
+		return FAILED;
+	}
+
+	if (this->dh_group != MODP_NONE)
+	{
+		this->dh = this->keymat->create_dh(this->keymat, this->dh_group);
+	}
+
+	if (this->config->use_ipcomp(this->config))
+	{
+		/* IPCOMP_DEFLATE is the only transform we support at the moment */
+		add_ipcomp_notify(this, message, IPCOMP_DEFLATE);
+	}
+
+	build_payloads(this, message);
+
+	this->tsi->destroy_offset(this->tsi, offsetof(traffic_selector_t, destroy));
+	this->tsr->destroy_offset(this->tsr, offsetof(traffic_selector_t, destroy));
+	this->proposals->destroy_offset(this->proposals, offsetof(proposal_t, destroy));
+	this->tsi = NULL;
+	this->tsr = NULL;
+	this->proposals = NULL;
+
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.process for responder
+ */
+static status_t process_r(private_child_create_t *this, message_t *message)
+{
+	switch (message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+			return get_nonce(message, &this->other_nonce);
+		case CREATE_CHILD_SA:
+			get_nonce(message, &this->other_nonce);
+			break;
+		case IKE_AUTH:
+			if (message->get_message_id(message) != 1)
+			{
+				/* only handle first AUTH payload, not additional rounds */
+				return NEED_MORE;
+			}
+		default:
+			break;
+	}
+
+	process_payloads(this, message);
+
+	return NEED_MORE;
+}
+
+/**
+ * handle CHILD_SA setup failure
+ */
+static void handle_child_sa_failure(private_child_create_t *this,
+									message_t *message)
+{
+	if (message->get_exchange_type(message) == IKE_AUTH &&
+		lib->settings->get_bool(lib->settings,
+								"charon.close_ike_on_child_failure", FALSE))
+	{
+		/* we delay the delete for 100ms, as the IKE_AUTH response must arrive
+		 * first */
+		DBG1(DBG_IKE, "closing IKE_SA due CHILD_SA setup failure");
+		charon->scheduler->schedule_job_ms(charon->scheduler, (job_t*)
+			delete_ike_sa_job_create(this->ike_sa->get_id(this->ike_sa), TRUE),
+			100);
+	}
+}
+
+/**
+ * Implementation of task_t.build for responder
+ */
+static status_t build_r(private_child_create_t *this, message_t *message)
+{
+	peer_cfg_t *peer_cfg;
+	payload_t *payload;
+	enumerator_t *enumerator;
+	bool no_dh = TRUE;
+
+	switch (message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+			return get_nonce(message, &this->my_nonce);
+		case CREATE_CHILD_SA:
+			if (generate_nonce(&this->my_nonce) != SUCCESS)
+			{
+				message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN,
+									chunk_empty);
+				return SUCCESS;
+			}
+			no_dh = FALSE;
+			break;
+		case IKE_AUTH:
+			if (this->ike_sa->get_state(this->ike_sa) != IKE_ESTABLISHED)
+			{	/* wait until all authentication round completed */
+				return NEED_MORE;
+			}
+		default:
+			break;
+	}
+
+	if (this->ike_sa->get_state(this->ike_sa) == IKE_REKEYING)
+	{
+		DBG1(DBG_IKE, "unable to create CHILD_SA while rekeying IKE_SA");
+		message->add_notify(message, TRUE, NO_ADDITIONAL_SAS, chunk_empty);
+		return SUCCESS;
+	}
+
+	peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
+	if (peer_cfg && this->tsi && this->tsr)
+	{
+		host_t *me, *other;
+
+		me = this->ike_sa->get_virtual_ip(this->ike_sa, TRUE);
+		if (me == NULL)
+		{
+			me = this->ike_sa->get_my_host(this->ike_sa);
+		}
+		other = this->ike_sa->get_virtual_ip(this->ike_sa, FALSE);
+		if (other == NULL)
+		{
+			other = this->ike_sa->get_other_host(this->ike_sa);
+		}
+		this->config = peer_cfg->select_child_cfg(peer_cfg, this->tsr,
+												  this->tsi, me, other);
+	}
+
+	if (this->config == NULL)
+	{
+		DBG1(DBG_IKE, "traffic selectors %#R=== %#R inacceptable",
+			 this->tsr, this->tsi);
+		message->add_notify(message, FALSE, TS_UNACCEPTABLE, chunk_empty);
+		handle_child_sa_failure(this, message);
+		return SUCCESS;
+	}
+
+	/* check if ike_config_t included non-critical error notifies */
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		if (payload->get_type(payload) == NOTIFY)
+		{
+			notify_payload_t *notify = (notify_payload_t*)payload;
+
+			switch (notify->get_notify_type(notify))
+			{
+				case INTERNAL_ADDRESS_FAILURE:
+				case FAILED_CP_REQUIRED:
+				{
+					DBG1(DBG_IKE,"configuration payload negotation "
+						 "failed, no CHILD_SA built");
+					enumerator->destroy(enumerator);
+					handle_child_sa_failure(this, message);
+					return SUCCESS;
+				}
+				default:
+					break;
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	this->child_sa = child_sa_create(this->ike_sa->get_my_host(this->ike_sa),
+			this->ike_sa->get_other_host(this->ike_sa), this->config, this->reqid,
+			this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY));
+
+	if (this->ipcomp_received != IPCOMP_NONE)
+	{
+		if (this->config->use_ipcomp(this->config))
+		{
+			add_ipcomp_notify(this, message, this->ipcomp_received);
+		}
+		else
+		{
+			DBG1(DBG_IKE, "received %N notify but IPComp is disabled, ignoring",
+				 notify_type_names, IPCOMP_SUPPORTED);
+		}
+	}
+
+	switch (select_and_install(this, no_dh))
+	{
+		case SUCCESS:
+			break;
+		case NOT_FOUND:
+			message->add_notify(message, FALSE, TS_UNACCEPTABLE, chunk_empty);
+			handle_child_sa_failure(this, message);
+			return SUCCESS;
+		case INVALID_ARG:
+		{
+			u_int16_t group = htons(this->dh_group);
+			message->add_notify(message, FALSE, INVALID_KE_PAYLOAD,
+								chunk_from_thing(group));
+			handle_child_sa_failure(this, message);
+			return SUCCESS;
+		}
+		case FAILED:
+		default:
+			message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN, chunk_empty);
+			handle_child_sa_failure(this, message);
+			return SUCCESS;
+	}
+
+	build_payloads(this, message);
+
+	DBG0(DBG_IKE, "CHILD_SA %s{%d} established "
+		 "with SPIs %.8x_i %.8x_o and TS %#R=== %#R",
+		 this->child_sa->get_name(this->child_sa),
+		 this->child_sa->get_reqid(this->child_sa),
+		 ntohl(this->child_sa->get_spi(this->child_sa, TRUE)),
+		 ntohl(this->child_sa->get_spi(this->child_sa, FALSE)),
+		 this->child_sa->get_traffic_selectors(this->child_sa, TRUE),
+		 this->child_sa->get_traffic_selectors(this->child_sa, FALSE));
+
+	if (!this->rekey)
+	{	/* invoke the child_up() hook if we are not rekeying */
+		charon->bus->child_updown(charon->bus, this->child_sa, TRUE);
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t process_i(private_child_create_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	payload_t *payload;
+	bool no_dh = TRUE;
+
+	switch (message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+			return get_nonce(message, &this->other_nonce);
+		case CREATE_CHILD_SA:
+			get_nonce(message, &this->other_nonce);
+			no_dh = FALSE;
+			break;
+		case IKE_AUTH:
+			if (this->ike_sa->get_state(this->ike_sa) != IKE_ESTABLISHED)
+			{	/* wait until all authentication round completed */
+				return NEED_MORE;
+			}
+		default:
+			break;
+	}
+
+	/* check for erronous notifies */
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		if (payload->get_type(payload) == NOTIFY)
+		{
+			notify_payload_t *notify = (notify_payload_t*)payload;
+			notify_type_t type = notify->get_notify_type(notify);
+
+			switch (type)
+			{
+				/* handle notify errors related to CHILD_SA only */
+				case NO_PROPOSAL_CHOSEN:
+				case SINGLE_PAIR_REQUIRED:
+				case NO_ADDITIONAL_SAS:
+				case INTERNAL_ADDRESS_FAILURE:
+				case FAILED_CP_REQUIRED:
+				case TS_UNACCEPTABLE:
+				case INVALID_SELECTORS:
+				{
+					DBG1(DBG_IKE, "received %N notify, no CHILD_SA built",
+						 notify_type_names, type);
+					enumerator->destroy(enumerator);
+					handle_child_sa_failure(this, message);
+					/* an error in CHILD_SA creation is not critical */
+					return SUCCESS;
+				}
+				case INVALID_KE_PAYLOAD:
+				{
+					chunk_t data;
+					u_int16_t group = MODP_NONE;
+
+					data = notify->get_notification_data(notify);
+					if (data.len == sizeof(group))
+					{
+						memcpy(&group, data.ptr, data.len);
+						group = ntohs(group);
+					}
+					DBG1(DBG_IKE, "peer didn't accept DH group %N, "
+						 "it requested %N", diffie_hellman_group_names,
+						 this->dh_group, diffie_hellman_group_names, group);
+					this->dh_group = group;
+					this->public.task.migrate(&this->public.task, this->ike_sa);
+					enumerator->destroy(enumerator);
+					return NEED_MORE;
+				}
+				default:
+					break;
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	process_payloads(this, message);
+
+	if (this->ipcomp == IPCOMP_NONE && this->ipcomp_received != IPCOMP_NONE)
+	{
+		DBG1(DBG_IKE, "received an IPCOMP_SUPPORTED notify without requesting"
+			 " one, no CHILD_SA built");
+		handle_child_sa_failure(this, message);
+		return SUCCESS;
+	}
+	else if (this->ipcomp != IPCOMP_NONE && this->ipcomp_received == IPCOMP_NONE)
+	{
+		DBG1(DBG_IKE, "peer didn't accept our proposed IPComp transforms, "
+			 "IPComp is disabled");
+		this->ipcomp = IPCOMP_NONE;
+	}
+	else if (this->ipcomp != IPCOMP_NONE && this->ipcomp != this->ipcomp_received)
+	{
+		DBG1(DBG_IKE, "received an IPCOMP_SUPPORTED notify we didn't propose, "
+			 "no CHILD_SA built");
+		handle_child_sa_failure(this, message);
+		return SUCCESS;
+	}
+
+	if (select_and_install(this, no_dh) == SUCCESS)
+	{
+		DBG0(DBG_IKE, "CHILD_SA %s{%d} established "
+			 "with SPIs %.8x_i %.8x_o and TS %#R=== %#R",
+			 this->child_sa->get_name(this->child_sa),
+			 this->child_sa->get_reqid(this->child_sa),
+			 ntohl(this->child_sa->get_spi(this->child_sa, TRUE)),
+			 ntohl(this->child_sa->get_spi(this->child_sa, FALSE)),
+			 this->child_sa->get_traffic_selectors(this->child_sa, TRUE),
+			 this->child_sa->get_traffic_selectors(this->child_sa, FALSE));
+
+		if (!this->rekey)
+		{	/* invoke the child_up() hook if we are not rekeying */
+			charon->bus->child_updown(charon->bus, this->child_sa, TRUE);
+		}
+	}
+	else
+	{
+		handle_child_sa_failure(this, message);
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.get_type
+ */
+static task_type_t get_type(private_child_create_t *this)
+{
+	return CHILD_CREATE;
+}
+
+/**
+ * Implementation of child_create_t.use_reqid
+ */
+static void use_reqid(private_child_create_t *this, u_int32_t reqid)
+{
+	this->reqid = reqid;
+}
+
+/**
+ * Implementation of child_create_t.get_child
+ */
+static child_sa_t* get_child(private_child_create_t *this)
+{
+	return this->child_sa;
+}
+
+/**
+ * Implementation of child_create_t.get_lower_nonce
+ */
+static chunk_t get_lower_nonce(private_child_create_t *this)
+{
+	if (memcmp(this->my_nonce.ptr, this->other_nonce.ptr,
+			   min(this->my_nonce.len, this->other_nonce.len)) < 0)
+	{
+		return this->my_nonce;
+	}
+	else
+	{
+		return this->other_nonce;
+	}
+}
+
+/**
+ * Implementation of task_t.migrate
+ */
+static void migrate(private_child_create_t *this, ike_sa_t *ike_sa)
+{
+	chunk_free(&this->my_nonce);
+	chunk_free(&this->other_nonce);
+	if (this->tsi)
+	{
+		this->tsr->destroy_offset(this->tsr, offsetof(traffic_selector_t, destroy));
+	}
+	if (this->tsr)
+	{
+		this->tsi->destroy_offset(this->tsi, offsetof(traffic_selector_t, destroy));
+	}
+	DESTROY_IF(this->child_sa);
+	DESTROY_IF(this->proposal);
+	DESTROY_IF(this->dh);
+	if (this->proposals)
+	{
+		this->proposals->destroy_offset(this->proposals, offsetof(proposal_t, destroy));
+	}
+
+	this->ike_sa = ike_sa;
+	this->keymat = ike_sa->get_keymat(ike_sa);
+	this->proposal = NULL;
+	this->proposals = NULL;
+	this->tsi = NULL;
+	this->tsr = NULL;
+	this->dh = NULL;
+	this->child_sa = NULL;
+	this->mode = MODE_TUNNEL;
+	this->ipcomp = IPCOMP_NONE;
+	this->ipcomp_received = IPCOMP_NONE;
+	this->other_cpi = 0;
+	this->reqid = 0;
+	this->established = FALSE;
+}
+
+/**
+ * Implementation of task_t.destroy
+ */
+static void destroy(private_child_create_t *this)
+{
+	chunk_free(&this->my_nonce);
+	chunk_free(&this->other_nonce);
+	if (this->tsr)
+	{
+		this->tsr->destroy_offset(this->tsr, offsetof(traffic_selector_t, destroy));
+	}
+	if (this->tsi)
+	{
+		this->tsi->destroy_offset(this->tsi, offsetof(traffic_selector_t, destroy));
+	}
+	if (!this->established)
+	{
+		DESTROY_IF(this->child_sa);
+	}
+	DESTROY_IF(this->packet_tsi);
+	DESTROY_IF(this->packet_tsr);
+	DESTROY_IF(this->proposal);
+	DESTROY_IF(this->dh);
+	if (this->proposals)
+	{
+		this->proposals->destroy_offset(this->proposals, offsetof(proposal_t, destroy));
+	}
+
+	DESTROY_IF(this->config);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+child_create_t *child_create_create(ike_sa_t *ike_sa,
+							child_cfg_t *config, bool rekey,
+							traffic_selector_t *tsi, traffic_selector_t *tsr)
+{
+	private_child_create_t *this = malloc_thing(private_child_create_t);
+
+	this->public.get_child = (child_sa_t*(*)(child_create_t*))get_child;
+	this->public.get_lower_nonce = (chunk_t(*)(child_create_t*))get_lower_nonce;
+	this->public.use_reqid = (void(*)(child_create_t*,u_int32_t))use_reqid;
+	this->public.task.get_type = (task_type_t(*)(task_t*))get_type;
+	this->public.task.migrate = (void(*)(task_t*,ike_sa_t*))migrate;
+	this->public.task.destroy = (void(*)(task_t*))destroy;
+	if (config)
+	{
+		this->public.task.build = (status_t(*)(task_t*,message_t*))build_i;
+		this->public.task.process = (status_t(*)(task_t*,message_t*))process_i;
+		this->initiator = TRUE;
+		config->get_ref(config);
+	}
+	else
+	{
+		this->public.task.build = (status_t(*)(task_t*,message_t*))build_r;
+		this->public.task.process = (status_t(*)(task_t*,message_t*))process_r;
+		this->initiator = FALSE;
+	}
+
+	this->ike_sa = ike_sa;
+	this->config = config;
+	this->my_nonce = chunk_empty;
+	this->other_nonce = chunk_empty;
+	this->proposals = NULL;
+	this->proposal = NULL;
+	this->tsi = NULL;
+	this->tsr = NULL;
+	this->packet_tsi = tsi ? tsi->clone(tsi) : NULL;
+	this->packet_tsr = tsr ? tsr->clone(tsr) : NULL;
+	this->dh = NULL;
+	this->dh_group = MODP_NONE;
+	this->keymat = ike_sa->get_keymat(ike_sa);
+	this->child_sa = NULL;
+	this->mode = MODE_TUNNEL;
+	this->ipcomp = IPCOMP_NONE;
+	this->ipcomp_received = IPCOMP_NONE;
+	this->my_spi = 0;
+	this->other_spi = 0;
+	this->my_cpi = 0;
+	this->other_cpi = 0;
+	this->reqid = 0;
+	this->established = FALSE;
+	this->rekey = rekey;
+
+	return &this->public;
+}