added PDF support for CHILD_SAs

support for INVALID_KE_PAYLOAD negotiation for rekeying
2007-04-19 08:02:19 +00:00
parent 41ab00da6b
commit 1fd5383e61
11 changed files with 361 additions and 190 deletions
@@ -26,6 +26,7 @@
 #include <daemon.h>
 #include <crypto/diffie_hellman.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>
@@ -88,6 +89,16 @@ struct private_child_create_t {
 	 */
 	linked_list_t *tsr;
 	
+	/**
+	 * optional diffie hellman exchange
+	 */
+	diffie_hellman_t *dh;
+	
+	/**
+	 * group used for DH exchange
+	 */
+	diffie_hellman_group_t dh_group;
+	
 	/**
 	 * mode the new CHILD_SA uses (transport/tunnel/beet)
 	 */
@@ -162,21 +173,29 @@ static bool ts_list_is_host(linked_list_t *list, host_t *host)
 }

 /**
- * Install a CHILD_SA for usage
+ * 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)
+static status_t select_and_install(private_child_create_t *this, bool no_dh)
 {
 	prf_plus_t *prf_plus;
 	status_t status;
-	chunk_t nonce_i, nonce_r, seed;
+	chunk_t nonce_i, nonce_r, secret, seed;
 	linked_list_t *my_ts, *other_ts;
 	host_t *me, *other, *other_vip, *my_vip;
 	
-	if (this->proposals == NULL || this->tsi == NULL || this->tsr == NULL)
+	if (this->proposals == NULL)
 	{
-		SIG(CHILD_UP_FAILED, "SA/TS payloads missing in message");
+		SIG(CHILD_UP_FAILED, "SA payload missing in message");
 		return FAILED;
 	}
+	if (this->tsi == NULL || this->tsr == NULL)
+	{
+		SIG(CHILD_UP_FAILED, "TS payloads missing in message");
+		return NOT_FOUND;
+	}
 	
 	if (this->initiator)
 	{
@@ -198,14 +217,34 @@ static status_t select_and_install(private_child_create_t *this)
 	my_vip = this->ike_sa->get_virtual_ip(this->ike_sa, TRUE);
 	other_vip = this->ike_sa->get_virtual_ip(this->ike_sa, FALSE);

-	this->proposal = this->config->select_proposal(this->config, this->proposals);
-	
+	this->proposal = this->config->select_proposal(this->config, this->proposals,
+												   no_dh);
 	if (this->proposal == NULL)
 	{
 		SIG(CHILD_UP_FAILED, "no acceptable proposal found");
 		return FAILED;
 	}
 	
+	if (!this->proposal->has_dh_group(this->proposal, this->dh_group))
+	{
+		algorithm_t *algo;
+		if (this->proposal->get_algorithm(this->proposal, DIFFIE_HELLMAN_GROUP,
+										  &algo))
+		{
+			u_int16_t group = algo->algorithm;
+			SIG(CHILD_UP_FAILED, "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;
+		}
+		else
+		{
+			SIG(CHILD_UP_FAILED, "no acceptable proposal found");
+			return FAILED;
+		}
+	}
+	
 	if (my_vip == NULL)
 	{
 		my_vip = me;
@@ -228,7 +267,7 @@ static status_t select_and_install(private_child_create_t *this)
 	if (my_ts->get_count(my_ts) == 0 || other_ts->get_count(other_ts) == 0)
 	{
 		SIG(CHILD_UP_FAILED, "no acceptable traffic selectors found");
-		return FAILED;
+		return NOT_FOUND;
 	}
 	
 	this->tsr->destroy_offset(this->tsr, offsetof(traffic_selector_t, destroy));
@@ -275,7 +314,20 @@ static status_t select_and_install(private_child_create_t *this)
 		}
 	}
 	
-	seed = chunk_cata("cc", nonce_i, nonce_r);
+	if (this->dh)
+	{
+		if (this->dh->get_shared_secret(this->dh, &secret) != SUCCESS)
+		{
+			SIG(CHILD_UP_FAILED, "DH exchange incomplete");
+			return FAILED;
+		}
+		DBG3(DBG_IKE, "DH secret %B", &secret);
+		seed = chunk_cata("mcc", secret, nonce_i, nonce_r);
+	}
+	else
+	{
+		seed = chunk_cata("cc", nonce_i, nonce_r);
+	}
 	prf_plus = prf_plus_create(this->ike_sa->get_child_prf(this->ike_sa), seed);
 	
 	if (this->initiator)
@@ -293,7 +345,7 @@ static status_t select_and_install(private_child_create_t *this)
 	if (status != SUCCESS)
 	{
 		SIG(CHILD_UP_FAILED, "unable to install IPsec SA (SAD) in kernel");
-		return status;
+		return FAILED;
 	}
 	
 	status = this->child_sa->add_policies(this->child_sa, my_ts, other_ts,
@@ -302,7 +354,7 @@ static status_t select_and_install(private_child_create_t *this)
 	if (status != SUCCESS)
 	{	
 		SIG(CHILD_UP_FAILED, "unable to install IPsec policies (SPD) in kernel");
-		return status;
+		return NOT_FOUND;
 	}
 	/* add to IKE_SA, and remove from task */
 	this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
@@ -317,8 +369,9 @@ static status_t select_and_install(private_child_create_t *this)
 static void build_payloads(private_child_create_t *this, message_t *message)
 {
 	sa_payload_t *sa_payload;
-	ts_payload_t *ts_payload;
 	nonce_payload_t *nonce_payload;
+	ke_payload_t *ke_payload;
+	ts_payload_t *ts_payload;

 	/* add SA payload */
 	if (this->initiator)
@@ -339,6 +392,13 @@ static void build_payloads(private_child_create_t *this, message_t *message)
 		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);
@@ -367,6 +427,7 @@ static void process_payloads(private_child_create_t *this, message_t *message)
 	iterator_t *iterator;
 	payload_t *payload;
 	sa_payload_t *sa_payload;
+	ke_payload_t *ke_payload;
 	ts_payload_t *ts_payload;
 	notify_payload_t *notify_payload;
 	
@@ -382,6 +443,19 @@ static void process_payloads(private_child_create_t *this, message_t *message)
 				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 = diffie_hellman_create(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);
@@ -429,6 +503,10 @@ static status_t build_i(private_child_create_t *this, message_t *message)
 				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_payload(message, ID_INITIATOR))
@@ -461,7 +539,8 @@ static status_t build_i(private_child_create_t *this, message_t *message)
 	}
 	this->tsr = this->config->get_traffic_selectors(this->config, FALSE, 
 													NULL, other);
-	this->proposals = this->config->get_proposals(this->config);
+	this->proposals = this->config->get_proposals(this->config,
+												  this->dh_group == MODP_NONE);
 	this->mode = this->config->get_mode(this->config);
 	
 	this->child_sa = child_sa_create(me, other,
@@ -476,6 +555,11 @@ static status_t build_i(private_child_create_t *this, message_t *message)
 		return FAILED;
 	}
 	
+	if (this->dh_group != MODP_NONE)
+	{
+		this->dh = diffie_hellman_create(this->dh_group);
+	}
+	
 	build_payloads(this, message);
 	
 	this->tsi->destroy_offset(this->tsi, offsetof(traffic_selector_t, destroy));
@@ -535,6 +619,8 @@ static status_t process_r(private_child_create_t *this, message_t *message)
 */
 static status_t build_r(private_child_create_t *this, message_t *message)
 {
+	bool no_dh = TRUE;
+
 	switch (message->get_exchange_type(message))
 	{
 		case IKE_SA_INIT:
@@ -545,6 +631,7 @@ static status_t build_r(private_child_create_t *this, message_t *message)
 				message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN, chunk_empty);
 				return SUCCESS;
 			}
+			no_dh = FALSE;
 			break;
 		case IKE_AUTH:
 			if (message->get_payload(message, EXTENSIBLE_AUTHENTICATION))
@@ -578,10 +665,24 @@ static status_t build_r(private_child_create_t *this, message_t *message)
 									 this->config, this->reqid,
 									 this->ike_sa->is_natt_enabled(this->ike_sa));
 	
-	if (select_and_install(this) != SUCCESS)
+	switch (select_and_install(this, no_dh))
 	{
-		message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN, chunk_empty);
-		return SUCCESS;
+		case SUCCESS:
+			break;
+		case NOT_FOUND:
+			message->add_notify(message, FALSE, TS_UNACCEPTABLE, chunk_empty);
+			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));
+			return SUCCESS;
+		}
+		case FAILED:
+		default:
+			message->add_notify(message, FALSE, NO_PROPOSAL_CHOSEN, chunk_empty);
+			return SUCCESS;
 	}
 	
 	build_payloads(this, message);
@@ -598,6 +699,7 @@ static status_t process_i(private_child_create_t *this, message_t *message)
 {
 	iterator_t *iterator;
 	payload_t *payload;
+	bool no_dh = TRUE;

 	switch (message->get_exchange_type(message))
 	{
@@ -605,6 +707,7 @@ static status_t process_i(private_child_create_t *this, message_t *message)
 			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 (message->get_payload(message, EXTENSIBLE_AUTHENTICATION))
@@ -642,6 +745,22 @@ static status_t process_i(private_child_create_t *this, message_t *message)
 					/* an error in CHILD_SA creation is not critical */
 					return SUCCESS;
 				}
+				case INVALID_KE_PAYLOAD:
+				{
+					chunk_t data;
+					diffie_hellman_group_t bad_group;
+					
+					bad_group = this->dh_group;
+					data = notify->get_notification_data(notify);
+					this->dh_group = ntohs(*((u_int16_t*)data.ptr));
+					DBG1(DBG_IKE, "peer didn't accept DH group %N, "
+						 "it requested %N", diffie_hellman_group_names,
+						 bad_group, diffie_hellman_group_names, this->dh_group);
+					
+					this->public.task.migrate(&this->public.task, this->ike_sa);
+					iterator->destroy(iterator);
+					return NEED_MORE;
+				}
 				default:
 					break;
 			}
@@ -651,7 +770,7 @@ static status_t process_i(private_child_create_t *this, message_t *message)
 	
 	process_payloads(this, message);
 	
-	if (select_and_install(this) == SUCCESS)
+	if (select_and_install(this, no_dh) == SUCCESS)
 	{
 		SIG(CHILD_UP_SUCCESS, "established CHILD_SA successfully");
 	}
@@ -715,6 +834,7 @@ static void migrate(private_child_create_t *this, ike_sa_t *ike_sa)
 	}
 	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));
@@ -724,6 +844,7 @@ static void migrate(private_child_create_t *this, ike_sa_t *ike_sa)
 	this->proposals = NULL;
 	this->tsi = NULL;
 	this->tsr = NULL;
+	this->dh = NULL;
 	this->child_sa = NULL;
 	this->mode = MODE_TUNNEL;
 	this->reqid = 0;
@@ -750,6 +871,7 @@ static void destroy(private_child_create_t *this)
 		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));
@@ -794,6 +916,8 @@ child_create_t *child_create_create(ike_sa_t *ike_sa, child_cfg_t *config)
 	this->proposal = NULL;
 	this->tsi = NULL;
 	this->tsr = NULL;
+	this->dh = NULL;
+	this->dh_group = MODP_NONE;
 	this->child_sa = NULL;
 	this->mode = MODE_TUNNEL;
 	this->reqid = 0;