code: def get_cdn_auth_token(self, app_id, hostname):
          
          return self.send_job_and_wait(MsgProto(EMsg.ClientGetCDNAuthToken),
                                        {
                                         'app_id': app_id,
                                         'host_name': hostname,
                                        },
                                        timeout=15
                                       )
docs: Get CDN authentication token
  
          :param app_id: app id
          :type app_id: :class:`int`
          :param hostname: cdn hostname
          :type hostname: :class:`str`
          :return: `CMsgClientGetCDNAuthTokenResponse <https://github.com/ValvePython/steam/blob/39627fe883feeed2206016bacd92cf0e4580ead6/protobufs/steammessages_clientserver_2.proto#L585-L589>`_
          :rtype: proto message