self.cid = cid
        self.csec = csec
        self.idp_ep = idp_ep
        self.sts_ep = sts_ep

        # Load CA certificates from SSL_CERT_FILE file if set
        ca_certs = os.environ.get('SSL_CERT_FILE')
        if not ca_certs:
            ca_certs = certifi.where()

        self._http = urllib3.PoolManager(
            timeout=urllib3.Timeout.DEFAULT_TIMEOUT,
            maxsize=10,