recognize strongSwan VID

src/pluto/vendor.c

@@ -375,7 +375,13 @@ static void handle_known_vendorid (struct msg_digest *md, const char *vidstr,
 	bool vid_useful = FALSE;
 	size_t i, j;
 
-	switch (vid->id) {
+	switch (vid->id)
+	 {
+		/* Remote side is a strongSwan host */
+		case VID_STRONGSWAN:
+			vid_useful = TRUE;
+			break;
+		
 		/* Remote side supports OpenPGP certificates */
 		case VID_OPENPGP:
 			md->openpgp = TRUE;