#!/usr/bin/python2

"""Asynchronous client using Twisted with GNUTLS"""

import sys
import os

from twisted.internet.error import ConnectionDone
from twisted.internet.protocol import ClientFactory
from twisted.protocols.basic import LineOnlyReceiver
from twisted.internet import reactor

from gnutls.constants import *
from gnutls.crypto import *
from gnutls.errors import *
from gnutls.interfaces.twisted import TLSContext, X509Credentials

class EchoProtocol(LineOnlyReceiver):

    def connectionMade(self):
        self.sendLine('echo')

    def lineReceived(self, line):
        print 'received: %s' % line
        self.transport.loseConnection()

    def connectionLost(self, reason):
        if reason.type != ConnectionDone:
            print "connection was lost: %s" % reason.value
        reactor.stop()

class EchoFactory(ClientFactory):
    protocol = EchoProtocol

    def clientConnectionFailed(self, connector, err):
        print "connection failed: %s" % err.value
        reactor.stop()


script_path = os.path.realpath(os.path.dirname(sys.argv[0]))
certs_path = os.path.join(script_path, 'certs')

cert = X509Certificate(open(certs_path + '/valid.crt').read())
key = X509PrivateKey(open(certs_path + '/valid.key').read())
ca = X509Certificate(open(certs_path + '/ca.pem').read())
crl = X509CRL(open(certs_path + '/crl.pem').read())
cred = X509Credentials(cert, key, [ca], [crl])
cred.verify_peer = True
context = TLSContext(cred, session_parameters="NORMAL:-COMP-ALL:+COMP-DEFLATE:+COMP-NULL")

reactor.connectTLS('localhost', 10000, EchoFactory(), context)
reactor.run()
