code: def _auth(self):
          
          if self.authenticated:
              self.__logger.debug("_auth: already authenticated")
              return
          self.__logger.debug("doing handshake...")
          hash_value=self._compute_handshake()
          n=common_root.newTextChild(None,"handshake",hash_value)
          self._write_node(n)
          n.unlinkNode()
          n.freeNode()
          self.__logger.debug("handshake hash sent.")
docs: Authenticate on the server.
  
          [component only]