Basic HTTP authentication with twisted not working

Question

I have the following code:

import sys

from zope.interface import implementer

from twisted.python import log
from twisted.internet import reactor
from twisted.web import server, resource, guard
from twisted.cred.portal import IRealm, Portal
from twisted.cred.checkers import InMemoryUsernamePasswordDatabaseDontUse


class GuardedResource(resource.Resource):
    """
    A resource which is protected by guard and requires authentication in order
    to access.
    """
    def getChild(self, path, request):
        return self


    def render(self, request):
        return "Authorized!"



@implementer(IRealm)
class SimpleRealm(object):
    """
    A realm which gives out L{GuardedResource} instances for authenticated
    users.
    """

    def requestAvatar(self, avatarId, mind, *interfaces):
        if resource.IResource in interfaces:
            return resource.IResource, GuardedResource(), lambda: None
        raise NotImplementedError()

def main():
    log.startLogging(sys.stdout)
    checkers = [InMemoryUsernamePasswordDatabaseDontUse(joe='blow')]
    portal = Portal(SimpleRealm(), checkers)

    resource = guard.HTTPAuthSessionWrapper(portal, [guard.BasicCredentialFactory('auth')])

    reactor.listenTCP(8889, server.Site(resource = resource))
    reactor.run()

if __name__ == '__main__':
    main()

when we start the server and visit the url: http://localhost:8889/ a prompt pop up and ask us to enter user and password. After entering user = joe and password = blow still we are not authorize to access the website. What is wrong in the code above and how to fix it?

Answer 1

So I posted on trac as suggested by @Jean-Paul Calderone and got the problem solved here

There are 2 things to be fixed

1. render method returns bytes in python3

    def render(self, request):
        return "Authorized!".encode('utf8')

2. password inside InMemoryUsernamePasswordDatabaseDontUse must be in bytes

    checkers = [InMemoryUsernamePasswordDatabaseDontUse(joe=b'blow')]

So for your code to run in py2 and py3 use this

from __future__ import print_function
import sys
from zope.interface import implementer
from twisted.python import log
from twisted.internet import reactor
from twisted.web import server, resource, guard
from twisted.cred.portal import IRealm, Portal
from twisted.cred.checkers import InMemoryUsernamePasswordDatabaseDontUse


class GuardedResource(resource.Resource):
    """
    A resource which is protected by guard and requires authentication in order
    to access.
    """
    def getChild(self, path, request):
        return self


    def render(self, request):
        return "Authorized!".encode('utf8')


@implementer(IRealm)
class SimpleRealm(object):
    """
    A realm which gives out L{GuardedResource} instances for authenticated
    users.
    """

    def requestAvatar(self, avatarId, mind, *interfaces):
        if resource.IResource in interfaces:
            return resource.IResource, GuardedResource(), lambda: None
        raise NotImplementedError()

def main():
    log.startLogging(sys.stdout)
    checkers = [InMemoryUsernamePasswordDatabaseDontUse(joe=b'blow')]
    portal = Portal(SimpleRealm(), checkers)

    resource = guard.HTTPAuthSessionWrapper(portal, [guard.BasicCredentialFactory('auth')])

    reactor.listenTCP(8889, server.Site(resource = resource))
    reactor.run()

if __name__ == '__main__':
    main()