XMLRPC server over HTTPS in Python 3

Question

I'm trying to implement a simple XML-RPC server on Python 3, and I want it to run over HTTPS using the standard ssl library (included in Python 2.6 and Python 3.x).

I've seen some code that does it with OpenSSL or M2Crypto modules, but I want to avoid any dependency.

I implemented the next code which should wrap the SSL protocol over the socket:

"""Monkey patching standard xmlrpc.server.SimpleXMLRPCServer
to run over TLS (SSL)

Changes inspired on http://www.cs.technion.ac.il/~danken/SecureXMLRPCServer.py
"""
import socket
import socketserver
import ssl
from xmlrpc.server import SimpleXMLRPCServer, SimpleXMLRPCDispatcher, SimpleXMLRPCRequestHandler
try:
    import fcntl
except ImportError:
    fcntl = None


class SimpleXMLRPCServerTLS(SimpleXMLRPCServer):
    def __init__(self, addr, requestHandler=SimpleXMLRPCRequestHandler,
                 logRequests=True, allow_none=False, encoding=None, bind_and_activate=True):
        """Overriding __init__ method of the SimpleXMLRPCServer

        The method is an exact copy, except the TCPServer __init__
        call, which is rewritten using TLS
        """
        self.logRequests = logRequests

        SimpleXMLRPCDispatcher.__init__(self, allow_none, encoding)

        """This is the modified part. Original code was:

            socketserver.TCPServer.__init__(self, addr, requestHandler, bind_and_activate)

        which executed:

            def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):
                BaseServer.__init__(self, server_address, RequestHandlerClass)
                self.socket = socket.socket(self.address_family,
                                            self.socket_type)
                if bind_and_activate:
                    self.server_bind()
                    self.server_activate()

        """
        socketserver.BaseServer.__init__(self, addr, requestHandler)
        self.socket = ssl.wrap_socket(
            socket.socket(self.address_family, self.socket_type),
            server_side=True,
            cert_reqs=ssl.CERT_NONE,
            ssl_version=ssl.PROTOCOL_TLSv1,
            )
        if bind_and_activate:
            self.server_bind()
            self.server_activate()

        """End of modified part"""

        # [Bug #1222790] If possible, set close-on-exec flag; if a
        # method spawns a subprocess, the subprocess shouldn't have
        # the listening socket open.
        if fcntl is not None and hasattr(fcntl, 'FD_CLOEXEC'):
            flags = fcntl.fcntl(self.fileno(), fcntl.F_GETFD)
            flags |= fcntl.FD_CLOEXEC
            fcntl.fcntl(self.fileno(), fcntl.F_SETFD, flags)

But for some reason I couldn't determine, it's raising this error:

[Errno 8] _ssl.c:502: EOF occurred in violation of protocol

before calling the remote method.

Does anyone knows what could be happening, or has any idea on how to gather more information to get a clue on what could be the problem?

Thank you so much in advance!

UPDATE:

Fixed. There were two errors on the code. First, it's necessary to specify the certificate file (which can include the key too).

Second is that xmlrpc.client.ServerProxy (included in Python) is using SSLv2, so TLSv1 does not work.

Working code is:

"""Monkey patching standard xmlrpc.server.SimpleXMLRPCServer
to run over TLS (SSL)

Changes inspired on http://www.cs.technion.ac.il/~danken/SecureXMLRPCServer.py
"""
import socket
import socketserver
import ssl
from xmlrpc.server import SimpleXMLRPCServer, SimpleXMLRPCDispatcher, SimpleXMLRPCRequestHandler
try:
    import fcntl
except ImportError:
    fcntl = None


class SimpleXMLRPCServerTLS(SimpleXMLRPCServer):
    def __init__(self, addr, requestHandler=SimpleXMLRPCRequestHandler,
                 logRequests=True, allow_none=False, encoding=None, bind_and_activate=True):
        """Overriding __init__ method of the SimpleXMLRPCServer

        The method is an exact copy, except the TCPServer __init__
        call, which is rewritten using TLS
        """
        self.logRequests = logRequests

        SimpleXMLRPCDispatcher.__init__(self, allow_none, encoding)

        """This is the modified part. Original code was:

            socketserver.TCPServer.__init__(self, addr, requestHandler, bind_and_activate)

        which executed:

            def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):
                BaseServer.__init__(self, server_address, RequestHandlerClass)
                self.socket = socket.socket(self.address_family,
                                            self.socket_type)
                if bind_and_activate:
                    self.server_bind()
                    self.server_activate()

        """
        socketserver.BaseServer.__init__(self, addr, requestHandler)
        self.socket = ssl.wrap_socket(
            socket.socket(self.address_family, self.socket_type),
            server_side=True,
            certfile='cert.pem',
            cert_reqs=ssl.CERT_NONE,
            ssl_version=ssl.PROTOCOL_SSLv23,
            )
        if bind_and_activate:
            self.server_bind()
            self.server_activate()

        """End of modified part"""

        # [Bug #1222790] If possible, set close-on-exec flag; if a
        # method spawns a subprocess, the subprocess shouldn't have
        # the listening socket open.
        if fcntl is not None and hasattr(fcntl, 'FD_CLOEXEC'):
            flags = fcntl.fcntl(self.fileno(), fcntl.F_GETFD)
            flags |= fcntl.FD_CLOEXEC
            fcntl.fcntl(self.fileno(), fcntl.F_SETFD, flags)

Answer 1

Why don't you write just like this:

server = SimpleXMLRPCServer(...)
...
server.socket = ssl.wrap_socket(srv.socket, ...)
server.serve_forever()