ftplib.py 文件源码

def auth(self):
            '''Set up secure control connection by using TLS/SSL.'''
            if isinstance(self.sock, ssl.SSLSocket):
                raise ValueError("Already using TLS")
            if self.ssl_version == ssl.PROTOCOL_TLSv1:
                resp = self.voidcmd('AUTH TLS')
            else:
                resp = self.voidcmd('AUTH SSL')
            server_hostname = self.host if ssl.HAS_SNI else None
            self.sock = self.context.wrap_socket(self.sock,
                                                 server_hostname=server_hostname)
            self.file = self.sock.makefile(mode='r', encoding=self.encoding)
            return resp