simple_httpclient.py 文件源码

def _on_resolve(self, addrinfo):
        af, sockaddr = addrinfo[0]

        if self.parsed.scheme == "https":
            ssl_options = {}
            if self.request.validate_cert:
                ssl_options["cert_reqs"] = ssl.CERT_REQUIRED
            if self.request.ca_certs is not None:
                ssl_options["ca_certs"] = self.request.ca_certs
            else:
                ssl_options["ca_certs"] = _DEFAULT_CA_CERTS
            if self.request.client_key is not None:
                ssl_options["keyfile"] = self.request.client_key
            if self.request.client_cert is not None:
                ssl_options["certfile"] = self.request.client_cert

            # SSL interoperability is tricky.  We want to disable
            # SSLv2 for security reasons; it wasn't disabled by default
            # until openssl 1.0.  The best way to do this is to use
            # the SSL_OP_NO_SSLv2, but that wasn't exposed to python
            # until 3.2.  Python 2.7 adds the ciphers argument, which
            # can also be used to disable SSLv2.  As a last resort
            # on python 2.6, we set ssl_version to SSLv3.  This is
            # more narrow than we'd like since it also breaks
            # compatibility with servers configured for TLSv1 only,
            # but nearly all servers support SSLv3:
            # http://blog.ivanristic.com/2011/09/ssl-survey-protocol-support.html
            if sys.version_info >= (2, 7):
                ssl_options["ciphers"] = "DEFAULT:!SSLv2"
            else:
                # This is really only necessary for pre-1.0 versions
                # of openssl, but python 2.6 doesn't expose version
                # information.
                ssl_options["ssl_version"] = ssl.PROTOCOL_SSLv3

            self.stream = SSLIOStream(socket.socket(af),
                                      io_loop=self.io_loop,
                                      ssl_options=ssl_options,
                                      max_buffer_size=self.max_buffer_size)
        else:
            self.stream = IOStream(socket.socket(af),
                                   io_loop=self.io_loop,
                                   max_buffer_size=self.max_buffer_size)
        timeout = min(self.request.connect_timeout, self.request.request_timeout)
        if timeout:
            self._timeout = self.io_loop.add_timeout(
                self.start_time + timeout,
                stack_context.wrap(self._on_timeout))
        self.stream.set_close_callback(self._on_close)
        # ipv6 addresses are broken (in self.parsed.hostname) until
        # 2.7, here is correctly parsed value calculated in __init__
        self.stream.connect(sockaddr, self._on_connect,
                            server_hostname=self.parsed_hostname)