Switch to alternative peer config in IKEv1 Main and Aggressive Mode.

src/libcharon/sa/ikev1/phase1.c

@@ -1,4 +1,7 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
  * Copyright (C) 2012 Martin Willi
  * Copyright (C) 2012 revosec AG
  *
@@ -19,6 +22,7 @@
 #include <sa/ikev1/keymat_v1.h>
 #include <encoding/payloads/ke_payload.h>
 #include <encoding/payloads/nonce_payload.h>
+#include <utils/linked_list.h>
 
 typedef struct private_phase1_t private_phase1_t;
 
@@ -37,6 +41,16 @@ struct private_phase1_t {
 	 */
 	ike_sa_t *ike_sa;
 
+	/**
+	 * Currently selected peer config
+	 */
+	peer_cfg_t *peer_cfg;
+
+	/**
+	 * Other possible peer config candidates
+	 */
+	linked_list_t *candidates;
+
 	/**
 	 * Acting as initiator
 	 */
@@ -513,9 +527,22 @@ METHOD(phase1_t, select_config, peer_cfg_t*,
 	identification_t *id)
 {
 	enumerator_t *enumerator;
-	peer_cfg_t *current, *found = NULL;
+	peer_cfg_t *current;
 	host_t *me, *other;
 
+	if (this->peer_cfg)
+	{	/* try to find an alternative config */
+		if (this->candidates->remove_first(this->candidates,
+										  (void**)&current) != SUCCESS)
+		{
+			DBG1(DBG_CFG, "no alternative config found");
+			return NULL;
+		}
+		DBG1(DBG_CFG, "switching to peer config '%s'",
+			 current->get_name(current));
+		return current;
+	}
+
 	me = this->ike_sa->get_my_host(this->ike_sa);
 	other = this->ike_sa->get_other_host(this->ike_sa);
 	DBG1(DBG_CFG, "looking for %N peer configs matching %H...%H[%Y]",
@@ -527,17 +554,27 @@ METHOD(phase1_t, select_config, peer_cfg_t*,
 		if (check_auth_method(this, current, method) &&
 			current->use_aggressive(current) == aggressive)
 		{
-			found = current->get_ref(current);
-			break;
+			current->get_ref(current);
+			if (!this->peer_cfg)
+			{
+				this->peer_cfg = current;
+			}
+			else
+			{
+				this->candidates->insert_last(this->candidates, current);
+			}
 		}
 	}
 	enumerator->destroy(enumerator);
 
-	if (found)
+	if (this->peer_cfg)
 	{
-		DBG2(DBG_CFG, "selected peer config \"%s\"", found->get_name(found));
+		DBG1(DBG_CFG, "selected peer config \"%s\"",
+			 this->peer_cfg->get_name(this->peer_cfg));
+		return this->peer_cfg->get_ref(this->peer_cfg);
 	}
-	return found;
+	DBG1(DBG_IKE, "no peer config found");
+	return NULL;
 }
 
 METHOD(phase1_t, get_id, identification_t*,
@@ -661,6 +698,9 @@ METHOD(phase1_t, get_nonce_ke, bool,
 METHOD(phase1_t, destroy, void,
 	private_phase1_t *this)
 {
+	DESTROY_IF(this->peer_cfg);
+	this->candidates->destroy_offset(this->candidates,
+									 offsetof(peer_cfg_t, destroy));
 	chunk_free(&this->sa_payload);
 	DESTROY_IF(this->dh);
 	free(this->dh_value.ptr);
@@ -691,6 +731,7 @@ phase1_t *phase1_create(ike_sa_t *ike_sa, bool initiator)
 			.get_nonce_ke = _get_nonce_ke,
 			.destroy = _destroy,
 		},
+		.candidates = linked_list_create(),
 		.ike_sa = ike_sa,
 		.initiator = initiator,
 		.keymat = (keymat_v1_t*)ike_sa->get_keymat(ike_sa),

src/libcharon/sa/ikev1/phase1.h

@@ -88,6 +88,9 @@ struct phase1_t {
 	/**
 	 * Select a peer config as responder.
 	 *
+	 * If called after the first successful call the next alternative config
+	 * is returned, if any.
+	 *
 	 * @param method		used authentication method
 	 * @param aggressive	TRUE to get an aggressive mode config
 	 * @param id			initiator identity

src/libcharon/sa/ikev1/tasks/aggressive_mode.c

@@ -1,4 +1,7 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
  * Copyright (C) 2012 Martin Willi
  * Copyright (C) 2012 revosec AG
  *
@@ -399,7 +402,6 @@ METHOD(task_t, process_r, status_t,
 													  this->method, TRUE, id);
 			if (!this->peer_cfg)
 			{
-				DBG1(DBG_IKE, "no peer config found");
 				return send_notify(this, AUTHENTICATION_FAILED);
 			}
 			this->ike_sa->set_peer_cfg(this->ike_sa, this->peer_cfg);
@@ -413,11 +415,22 @@ METHOD(task_t, process_r, status_t,
 		}
 		case AM_AUTH:
 		{
-			if (!this->ph1->verify_auth(this->ph1, this->method, message,
-										this->id_data))
+			while (TRUE)
 			{
-				this->id_data = chunk_empty;
-				return send_delete(this);
+				if (this->ph1->verify_auth(this->ph1, this->method, message,
+										   this->id_data))
+				{
+					break;
+				}
+				this->peer_cfg->destroy(this->peer_cfg);
+				this->peer_cfg = this->ph1->select_config(this->ph1,
+													this->method, TRUE, NULL);
+				if (!this->peer_cfg)
+				{
+					this->id_data = chunk_empty;
+					return send_delete(this);
+				}
+				this->ike_sa->set_peer_cfg(this->ike_sa, this->peer_cfg);
 			}
 			this->id_data = chunk_empty;
 

src/libcharon/sa/ikev1/tasks/main_mode.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Tobias Brunner
+ * Copyright (C) 2011-2012 Tobias Brunner
  * Hochschule fuer Technik Rapperswil
  *
  * Copyright (C) 2011 Martin Willi
@@ -405,23 +405,27 @@ METHOD(task_t, process_r, status_t,
 				DBG1(DBG_IKE, "IDii payload missing");
 				return send_notify(this, INVALID_PAYLOAD_TYPE);
 			}
-
 			id = id_payload->get_identification(id_payload);
 			this->ike_sa->set_other_id(this->ike_sa, id);
-			this->peer_cfg = this->ph1->select_config(this->ph1,
-													  this->method, FALSE, id);
-			if (!this->peer_cfg)
-			{
-				DBG1(DBG_IKE, "no peer config found");
-				return send_notify(this, AUTHENTICATION_FAILED);
-			}
-			this->ike_sa->set_peer_cfg(this->ike_sa, this->peer_cfg);
 
-			if (!this->ph1->verify_auth(this->ph1, this->method, message,
-										id_payload->get_encoded(id_payload)))
+			while (TRUE)
 			{
-				return send_notify(this, AUTHENTICATION_FAILED);
+				DESTROY_IF(this->peer_cfg);
+				this->peer_cfg = this->ph1->select_config(this->ph1,
+													this->method, FALSE, id);
+				if (!this->peer_cfg)
+				{
+					return send_notify(this, AUTHENTICATION_FAILED);
+				}
+				this->ike_sa->set_peer_cfg(this->ike_sa, this->peer_cfg);
+
+				if (this->ph1->verify_auth(this->ph1, this->method, message,
+										   id_payload->get_encoded(id_payload)))
+				{
+					break;
+				}
 			}
+
 			if (!charon->bus->authorize(charon->bus, FALSE))
 			{
 				DBG1(DBG_IKE, "Main Mode authorization hook forbids IKE_SA, "