ikev2: Add task that verifies a peer's certificate

On failure the SA is deleted and reestablished as configured.  The task
is activated after the REAUTH_COMPLETE task so a make-before-break reauth
is completed before the new SA might get torn down.

src/libcharon/Android.mk

@@ -111,7 +111,8 @@ sa/ikev2/tasks/ike_reauth.c sa/ikev2/tasks/ike_reauth.h \
 sa/ikev2/tasks/ike_reauth_complete.c sa/ikev2/tasks/ike_reauth_complete.h \
 sa/ikev2/tasks/ike_redirect.c sa/ikev2/tasks/ike_redirect.h \
 sa/ikev2/tasks/ike_auth_lifetime.c sa/ikev2/tasks/ike_auth_lifetime.h \
-sa/ikev2/tasks/ike_vendor.c sa/ikev2/tasks/ike_vendor.h
+sa/ikev2/tasks/ike_vendor.c sa/ikev2/tasks/ike_vendor.h \
+sa/ikev2/tasks/ike_verify_peer_cert.c sa/ikev2/tasks/ike_verify_peer_cert.h
 
 libcharon_la_SOURCES += \
 sa/ikev1/keymat_v1.c sa/ikev1/keymat_v1.h \

src/libcharon/Makefile.am

@@ -111,7 +111,8 @@ sa/ikev2/tasks/ike_reauth.c sa/ikev2/tasks/ike_reauth.h \
 sa/ikev2/tasks/ike_reauth_complete.c sa/ikev2/tasks/ike_reauth_complete.h \
 sa/ikev2/tasks/ike_redirect.c sa/ikev2/tasks/ike_redirect.h \
 sa/ikev2/tasks/ike_auth_lifetime.c sa/ikev2/tasks/ike_auth_lifetime.h \
-sa/ikev2/tasks/ike_vendor.c sa/ikev2/tasks/ike_vendor.h
+sa/ikev2/tasks/ike_vendor.c sa/ikev2/tasks/ike_vendor.h \
+sa/ikev2/tasks/ike_verify_peer_cert.c sa/ikev2/tasks/ike_verify_peer_cert.h
 endif
 
 if USE_IKEV1

src/libcharon/sa/ikev2/task_manager_v2.c

@@ -527,6 +527,11 @@ METHOD(task_manager_t, initiate, status_t,
 					exchange = INFORMATIONAL;
 					break;
 				}
+				if (activate_task(this, TASK_IKE_VERIFY_PEER_CERT))
+				{
+					exchange = INFORMATIONAL;
+					break;
+				}
 			case IKE_REKEYING:
 				if (activate_task(this, TASK_IKE_DELETE))
 				{

src/libcharon/sa/ikev2/tasks/ike_verify_peer_cert.c

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2015 Tobias Brunner
+ * 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 "ike_verify_peer_cert.h"
+
+#include <daemon.h>
+#include <sa/ikev2/tasks/ike_delete.h>
+
+typedef struct private_ike_verify_peer_cert_t private_ike_verify_peer_cert_t;
+
+/**
+ * Private members
+ */
+struct private_ike_verify_peer_cert_t {
+
+	/**
+	 * Public methods and task_t interface.
+	 */
+	ike_verify_peer_cert_t public;
+
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+
+	/**
+	 * Child ike_delete task, if necessary
+	 */
+	ike_delete_t *ike_delete;
+};
+
+METHOD(task_t, build_i, status_t,
+	private_ike_verify_peer_cert_t *this, message_t *message)
+{
+	if (!this->ike_sa->verify_peer_certificate(this->ike_sa))
+	{
+		DBG1(DBG_IKE, "peer certificate verification failed, deleting SA");
+		this->ike_delete = ike_delete_create(this->ike_sa, TRUE);
+		return this->ike_delete->task.build(&this->ike_delete->task, message);
+	}
+	DBG1(DBG_IKE, "peer certificate successfully verified");
+	message->set_exchange_type(message, EXCHANGE_TYPE_UNDEFINED);
+	return SUCCESS;
+}
+
+METHOD(task_t, process_i, status_t,
+	private_ike_verify_peer_cert_t *this, message_t *message)
+{
+	if (this->ike_delete)
+	{
+		this->ike_delete->task.process(&this->ike_delete->task, message);
+		/* try to reestablish the IKE_SA and all children */
+		this->ike_sa->reestablish(this->ike_sa);
+	}
+	return DESTROY_ME;
+}
+
+METHOD(task_t, get_type, task_type_t,
+	private_ike_verify_peer_cert_t *this)
+{
+	return TASK_IKE_VERIFY_PEER_CERT;
+}
+
+METHOD(task_t, migrate, void,
+	private_ike_verify_peer_cert_t *this, ike_sa_t *ike_sa)
+{
+	if (this->ike_delete)
+	{
+		this->ike_delete->task.migrate(&this->ike_delete->task, ike_sa);
+	}
+	this->ike_sa = ike_sa;
+}
+
+METHOD(task_t, destroy, void,
+	private_ike_verify_peer_cert_t *this)
+{
+	if (this->ike_delete)
+	{
+		this->ike_delete->task.destroy(&this->ike_delete->task);
+	}
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+ike_verify_peer_cert_t *ike_verify_peer_cert_create(ike_sa_t *ike_sa)
+{
+	private_ike_verify_peer_cert_t *this;
+
+	INIT(this,
+		.public = {
+			.task = {
+				.get_type = _get_type,
+				.migrate = _migrate,
+				.build = _build_i,
+				.process = _process_i,
+				.destroy = _destroy,
+			},
+		},
+		.ike_sa = ike_sa,
+	);
+
+	return &this->public;
+}

src/libcharon/sa/ikev2/tasks/ike_verify_peer_cert.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015 Tobias Brunner
+ * 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.
+ */
+
+/**
+ * @defgroup ike_verify_peer_cert ike_verify_peer_cert
+ * @{ @ingroup tasks_v2
+ */
+
+#ifndef IKE_VERIFY_PEER_CERT_H_
+#define IKE_VERIFY_PEER_CERT_H_
+
+typedef struct ike_verify_peer_cert_t ike_verify_peer_cert_t;
+
+#include <library.h>
+#include <sa/ike_sa.h>
+#include <sa/task.h>
+
+/**
+ * Task of type ike_verify_peer_cert, verifies a peer's certificate.
+ *
+ * This task (re-)verifies the peer's certificate explicitly including online
+ * OCSP and CRL checks.
+ */
+struct ike_verify_peer_cert_t {
+
+	/**
+	 * Implements the task_t interface
+	 */
+	task_t task;
+};
+
+/**
+ * Create a new ike_verify_peer_cert task.
+ *
+ * This task is initiator only.
+ *
+ * @param ike_sa		IKE_SA this task works for
+ * @return				ike_verify_peer_cert task to handle by the task_manager
+ */
+ike_verify_peer_cert_t *ike_verify_peer_cert_create(ike_sa_t *ike_sa);
+
+#endif /** IKE_VERIFY_PEER_CERT_H_ @}*/

src/libcharon/sa/task.c

@@ -29,6 +29,7 @@ ENUM(task_type_names, TASK_IKE_INIT, TASK_ISAKMP_CERT_POST,
 	"IKE_REAUTH",
 	"IKE_REAUTH_COMPLETE",
 	"IKE_REDIRECT",
+	"IKE_VERIFY_PEER_CERT",
 	"IKE_DELETE",
 	"IKE_DPD",
 	"IKE_VENDOR",

src/libcharon/sa/task.h

@@ -59,6 +59,8 @@ enum task_type_t {
 	TASK_IKE_REAUTH_COMPLETE,
 	/** redirect an active IKE_SA */
 	TASK_IKE_REDIRECT,
+	/** verify a peer's certificate */
+	TASK_IKE_VERIFY_PEER_CERT,
 	/** delete an IKE_SA */
 	TASK_IKE_DELETE,
 	/** liveness check */