#!/usr/bin/env python2

import uuid
import hashlib
from xmlrpc.server import SimpleXMLRPCServer
from xmlrpc.server import SimpleXMLRPCRequestHandler

# Restrict to a particular path.
class RequestHandler(SimpleXMLRPCRequestHandler):
    rpc_paths = ('/RPC2',)

# Create server
server = SimpleXMLRPCServer(("localhost", 8000),
                            requestHandler=RequestHandler)
server.register_introspection_functions()


# Register an instance; all the methods of the instance are
# published as XML-RPC methods
class CHAP:
    test_password = 'Test123'
    # initializes class-instance and instance variables
    def __init__(self):
        self.key = '';
        self.authenticated = False;

    # tells the server to start the autentification process
    # and send the generated random salt
    def init(self):
        self.key = str( uuid.uuid4() )
        return self.key

    # checks if send hash is same as internally generated to validate if the correct
    # password was used
    def auth(self, password_hash):
        combined = CHAP.test_password + self.key
        passhash = hashlib.sha256( combined.encode( 'utf-8' ) ).hexdigest()
        self.authenticated = passhash == password_hash
        return self.authenticated

    # a little method that refuses to say hi, if you
    # are not authenticated
    def hello(self):
        if ( self.authenticated ):
            return 'Hi, you are authenticated'
        else:
            return 'Sorry, please authenticate first'
server.register_instance(CHAP())
# Run the server's main loop
server.serve_forever()