'This is the "info callback" on the context.  It will be called
periodically by pyOpenSSL with information about the state of a
connection.  When it indicates the handshake is complete, it will fire
C{self._finished}.'

def _info(self, connection, where, ret):

    if (where & self.SSL_CB_HANDSHAKE_DONE):
        self._finished.callback(None)
