Method __negotiatesocks5

thirdparty/socks/socks.py:171–261

__negotiatesocks5(self,destaddr,destport) Negotiates a connection through a SOCKS5 server.

(self, destaddr, destport)

        self.__proxy = (proxytype, addr, port, rdns, username, password)

    def __negotiatesocks5(self, destaddr, destport):
        """__negotiatesocks5(self,destaddr,destport)
        Negotiates a connection through a SOCKS5 server.
        """
        # First we'll send the authentication packages we support.
        if (self.__proxy[4]!=None) and (self.__proxy[5]!=None):
            # The username/password details were supplied to the
            # setproxy method so we support the USERNAME/PASSWORD
            # authentication (in addition to the standard none).
            self.sendall(struct.pack('BBBB', 0x05, 0x02, 0x00, 0x02))
        else:
            # No username/password were entered, therefore we
            # only support connections with no authentication.
            self.sendall(struct.pack('BBB', 0x05, 0x01, 0x00))
        # We'll receive the server's response to determine which
        # method was selected
        chosenauth = self.__recvall(2)
        if chosenauth[0:1] != b'\x05':
            self.close()
            raise GeneralProxyError((1, _generalerrors[1]))
        # Check the chosen authentication method
        if chosenauth[1:2] == b'\x00':
            # No authentication is required
            pass
        elif chosenauth[1:2] == b'\x02':
            # Okay, we need to perform a basic username/password
            # authentication.
            self.sendall(b'\x01' + chr(len(self.__proxy[4])).encode() + self.__proxy[4].encode() + chr(len(self.__proxy[5])).encode() + self.__proxy[5].encode())
            authstat = self.__recvall(2)
            if authstat[0:1] != b'\x01':
                # Bad response
                self.close()
                raise GeneralProxyError((1, _generalerrors[1]))
            if authstat[1:2] != b'\x00':
                # Authentication failed
                self.close()
                raise Socks5AuthError((3, _socks5autherrors[3]))
            # Authentication succeeded
        else:
            # Reaching here is always bad
            self.close()
            if chosenauth[1:2] == b'\xff':
                raise Socks5AuthError((2, _socks5autherrors[2]))
            else:
                raise GeneralProxyError((1, _generalerrors[1]))
        # Now we can request the actual connection
        req = struct.pack('BBB', 0x05, 0x01, 0x00)
        # If the given destination address is an IP address, we'll
        # use the IPv4 address request even if remote resolving was specified.
        try:
            ipaddr = socket.inet_aton(destaddr)
            req = req + b'\x01' + ipaddr
        except socket.error:
            # Well it's not an IP number,  so it's probably a DNS name.
            if self.__proxy[3]:
                # Resolve remotely
                ipaddr = None
                req = req + chr(0x03).encode() + chr(len(destaddr)).encode() + (destaddr if isinstance(destaddr, bytes) else destaddr.encode())