Fetching certificates if there is an eception during verifiaction of the

singned token.

Change-Id: I0f0cc0f5f7fab7a46c67111d9a1cce3f94c6cb18
Closes-Bug: 1413082

src/config/api-server/vnc_auth_keystone.py

@@ -235,7 +235,13 @@ def verify_signed_token(self, user_token):
         try:
             return self._auth_middleware.verify_signed_token(user_token)
         except:
-            return None
+            # Retry verify after fetching the certs.
+            try:
+                self._auth_middleware.fetch_signing_cert()
+                self._auth_middleware.fetch_ca_cert()
+                return self._auth_middleware.verify_signed_token(user_token)
+            except:
+                return None
     # end
 
     # convert keystone user id to name