def _do_ssl_handshake(self):
        # Based on code from test_ssl.py in the python stdlib
        try:
            self._handshake_reading = False
            self._handshake_writing = False
            self.socket.do_handshake()
        except ssl.SSLError as err:
            if err.args[0] == ssl.SSL_ERROR_WANT_READ:
                self._handshake_reading = True
                return
            elif err.args[0] == ssl.SSL_ERROR_WANT_WRITE:
                self._handshake_writing = True
                return
            elif err.args[0] in (ssl.SSL_ERROR_EOF,
                                 ssl.SSL_ERROR_ZERO_RETURN):
                return self.close(exc_info=True)
            elif err.args[0] == ssl.SSL_ERROR_SSL:
                try:
                    peer = self.socket.getpeername()
                except Exception:
                    peer = '(not connected)'
                gen_log.warning("SSL Error on %s %s: %s",
                                self.socket.fileno(), peer, err)
                return self.close(exc_info=True)
            raise
        except socket.error as err:
            if err.args[0] in _ERRNO_CONNRESET:
                return self.close(exc_info=True)
        except __HOLE__:
            # On Linux, if the connection was reset before the call to
            # wrap_socket, do_handshake will fail with an
            # AttributeError.
            return self.close(exc_info=True)
        else:
            self._ssl_accepting = False
            if not self._verify_cert(self.socket.getpeercert()):
                self.close()
                return
            if self._ssl_connect_callback is not None:
                callback = self._ssl_connect_callback
                self._ssl_connect_callback = None
                self._run_callback(callback)
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/iostream.py/SSLIOStream._do_ssl_handshake