From: Tobias Brunner <tobias@strongswan.org>
Date: Fri, 2 Feb 2018 09:26:36 +0000 (+0100)
Subject: ike-init: Move creation of DH instance after INVALID_KE_PAYLOAD to build_i()
X-Git-Tag: 5.6.2rc1~19^2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18242f62c27bf829fd8ea8bbfc08e517fa9a2965;p=thirdparty%2Fstrongswan.git

ike-init: Move creation of DH instance after INVALID_KE_PAYLOAD to build_i()

This way we get proper error handling if the DH group the peer requested
is not actually supported for some reason (otherwise we'd just retry to
initiate with the configured group and get back another notify).
---

diff --git a/src/libcharon/sa/ikev2/tasks/ike_init.c b/src/libcharon/sa/ikev2/tasks/ike_init.c
index d75d217150..635c32c0d2 100644
--- a/src/libcharon/sa/ikev2/tasks/ike_init.c
+++ b/src/libcharon/sa/ikev2/tasks/ike_init.c
@@ -544,6 +544,18 @@ METHOD(task_t, build_i, status_t,
 			return FAILED;
 		}
 	}
+	else if (this->dh->get_dh_group(this->dh) != this->dh_group)
+	{	/* reset DH instance if group changed (INVALID_KE_PAYLOAD) */
+		this->dh->destroy(this->dh);
+		this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
+												  this->dh_group);
+		if (!this->dh)
+		{
+			DBG1(DBG_IKE, "requested DH group %N not supported",
+				 diffie_hellman_group_names, this->dh_group);
+			return FAILED;
+		}
+	}
 
 	/* generate nonce only when we are trying the first time */
 	if (this->my_nonce.ptr == NULL)
@@ -929,12 +941,6 @@ METHOD(task_t, migrate, void,
 	this->keymat = (keymat_v2_t*)ike_sa->get_keymat(ike_sa);
 	this->proposal = NULL;
 	this->dh_failed = FALSE;
-	if (this->dh && this->dh->get_dh_group(this->dh) != this->dh_group)
-	{	/* reset DH value only if group changed (INVALID_KE_PAYLOAD) */
-		this->dh->destroy(this->dh);
-		this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat,
-												  this->dh_group);
-	}
 }
 
 METHOD(task_t, destroy, void,