'Get the certificate information for this domain:port
:param url: The URL we want to query (we get the port from here)
:param domain: The domain to connect to
:return: A tuple with:
* cert
* cert_der
* cipher'

def _get_cert(self, url, domain):

    for extract_method in (self._get_ca_signed_cert, self._self_signed_cert):
        try:
            return extract_method(url, domain)
        except RuntimeError as rte:
            om.out.debug(str(rte))
    raise rte
