imaplib2.py 文件源码

def ssl_wrap_socket(self):

        # Allow sending of keep-alive messages - seems to prevent some servers
        # from closing SSL, leading to deadlocks.
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)

        try:
            import ssl
            if self.ca_certs is not None:
                cert_reqs = ssl.CERT_REQUIRED
            else:
                cert_reqs = ssl.CERT_NONE

            if self.ssl_version == "tls1":
                ssl_version = ssl.PROTOCOL_TLSv1
            elif self.ssl_version == "ssl2":
                ssl_version = ssl.PROTOCOL_SSLv2
            elif self.ssl_version == "ssl3":
                ssl_version = ssl.PROTOCOL_SSLv3
            elif self.ssl_version == "ssl23" or self.ssl_version is None:
                ssl_version = ssl.PROTOCOL_SSLv23
            else:
                raise socket.sslerror("Invalid SSL version requested: %s", self.ssl_version)

            self.sock = ssl.wrap_socket(self.sock, self.keyfile, self.certfile, ca_certs=self.ca_certs, cert_reqs=cert_reqs, ssl_version=ssl_version)
            ssl_exc = ssl.SSLError
            self.read_fd = self.sock.fileno()
        except ImportError:
            # No ssl module, and socket.ssl has no fileno(), and does not allow certificate verification
            raise socket.sslerror("imaplib2 SSL mode does not work without ssl module")

        if self.cert_verify_cb is not None:
            cert_err = self.cert_verify_cb(self.sock.getpeercert(), self.host)
            if cert_err:
                raise ssl_exc(cert_err)