Mailman 3 July 2010 - Twisted

[Twisted-Python] Newbie: using cred strcred.AuthOptionMixin
by Schneider 06 Jul '10

06 Jul '10

Hi, I need a perspective broker with authentification and followed the Twisted documentation on http://twistedmatrix.com/documents/current/core/howto/tap.html#auto4 to get the twistd plugin to work. Now I want to make it work with the /etc/shadow, but don't know how to get it to work. The plugin looks like: ----------------------------------------------------------------------- from zope.interface import implements from twisted.python import usage from twisted.plugin import IPlugin from twisted.application.service import IServiceMaker from twisted.application import internet from twisted.cred import credentials, portal, strcred from twisted.spread import pb from qxmt.QXMTServer import QXMTUser class Options(usage.Options, strcred.AuthOptionMixin): # This part is optional; it tells AuthOptionMixin what # kinds of credential interfaces the user can give us. supportedInterfaces = (credentials.IUsernamePassword,) optParameters = [["port", "p", 8789, "Server port number"]] class QXMTRealm: implements(portal.IRealm) def requestAvatar(self, avatarId, mind, *interfaces): if pb.IPerspective not in interfaces: raise NotImplementedError return pb.IPerspective, QXMTUser(avatarId), lambda: None class QXMTServiceMaker(object): implements(IServiceMaker, IPlugin) tapname = "qxmt" description = "The QXtend remote error processing tool." options = Options def makeService(self, options): """ Construct a TCPServer from a factory defined in qxmt. """ p = portal.Portal(QXMTRealm(), options["credCheckers"]) #c = checkers.InMemoryUsernamePasswordDatabaseDontUse(user1="pass1", #p.registerChecker(c) return internet.TCPServer(int(options['port']), pb.PBServerFactory(p)) serviceMaker = QXMTServiceMaker() ----------------------------------------------------------------------- Running twistd qxmt --help-auth gives Usage: --auth AuthType[:ArgString] For detailed help: --help-auth-type AuthType AuthType ArgString format ======== ================ memory A colon-separated list (name:password:...) file Location of a FilePasswordDB-formatted file. unix No argstring required. And twistd qxmt --help-auth-type unix gives Usage: --auth unix[:ArgString] ArgString format: No argstring required. This checker will attempt to use every resource available to authenticate against the list of users on the local UNIX system. (This does not support Windows servers for very obvious reasons.) Right now, this includes support for: * Python's pwd module (which checks /etc/passwd) * Python's spwd module (which checks /etc/shadow) Future versions may include support for PAM authentication. So, I guess the server now should be able to use the system's shadow passwords for authentification. As a client I used with the InMemoryUsernamePasswordDatabaseDontUse checker the following code. ----------------------------------------------------------------------- #!/usr/bin/env python # Copyright (c) 2009 Twisted Matrix Laboratories. # See LICENSE for details. from twisted.spread import pb from twisted.internet import reactor from twisted.cred import credentials def main(): factory = pb.PBClientFactory() reactor.connectTCP("localhost", 8789, factory) def1 = factory.login(credentials.UsernamePassword("user1", "pass1")) def1.addCallback(connected) reactor.run() def connected(perspective): print "got perspective1 ref:", perspective print "asking it to foo(13)" perspective.callRemote("foo", 13) main() ----------------------------------------------------------------------- How to rewrite the client to make it work with --auth=unix ? Thanks, Frans

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[Twisted-Python] Advice seeked on SMPP implementation
by Yaroslav Fedevych 06 Jul '10

06 Jul '10

Hello, I'm currently busy with implementing SMPP in Twisted, and there is something I would like to have a piece of advice with. If I'm going to make it internal to my needs, there's only issue of making it work and be done with it. But that's not quite a way I would like to do it; I would like to end up with an implementation which would be reusable and beneficial for the community as well, so that anyone would be then able to take this implementation and get his or her service an almost instant ability to talk SMPP (news via SMS? microblogging via SMS? ...) Thus keeping in mind that SMPP by its nature is not entirely unlike your old instant messaging and mailing protocols, albeit geared towards mobile content, there might be some interfaces already in Twisted which I would need to implement before it becomes interesting to anyone else. Can anyone give me some useful pointers on that? P. S. I have seen some SMPP-related discussions popping up on this list, but it seems that to date, nothing open source and under active development and maintenance has been produced so far. -- Engineer : How do I do it? Economist : How much will it cost? Twisted Developer: Will it block?

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[Twisted-Python] relative priority of deprecation tickets
by Glyph Lefkowitz 06 Jul '10

06 Jul '10

Hello there everybody - and by "everybody" I mostly mean "thijs" :-). I've noticed that there is an increasing proliferation of small, "remove some deprecated stuff" tickets in the Twisted tracker. While, nominally, according to our own process, everything that is deprecated should eventually be removed, some removals should be more eventual than others. For example, Jean-Paul Calderone had this to say (on IRC) about <http://twistedmatrix.com/trac/ticket/4548>: <exarkun> The thing that's deprecated in twisted.news.nntp is supporting applications that return a string from a particular api instead of an Article instance <exarkun> The support code for that case is one line <exarkun> In the 6 years it has existed, it has cost zero maintenance time The real purpose of these 'removal' tickets is to reduce maintenance overhead by eliminating redundant code that doesn't need to be maintained, and shouldn't be presented to new users (in API docs, in examples, etc). Some code really does produce a maintenance burden and needs to be thought about a lot. But we can really afford to let innocuous one-liners slide for quite a long time; in the meanwhile, all they're doing is providing a more useful error message for developers using the older API. Of course, small maintenance tickets like this do serve as a way to provide 'easy' work to newcomers, and that's great. But if newcomers are going to do easy things, a much more worthwhile type of grunt-work would be for them to remove warnings that Twisted itself, especially 'trial twisted' is _emitting_. Similarly, if anyone would like to spend time filing individual tickets to provide more fine-grained warning-removal tickets ("twisted emits warnings" is obviously way too big for one patch) that would be more helpful. If you are going to file tickets for removing code that nobody is really having to maintain at the moment, please set their priority to 'lowest', since leaving them at 'normal' creates the misleading impression that they are just as important as fixing bugs, adding documentation or implementing features.

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[Twisted-Python] Implementing OAuth in twisted.cred
by Laurens Van Houtven 05 Jul '10

05 Jul '10

Hi! For those who don't know what OAuth is; the Wikipedia definition is pretty good: "OAuth (Open Authorization) is an open standard that allows users to share their private resources (e.g. photos, videos, contact lists) stored on one site with another site without having to hand out their username and password." It is currently being used by big names like Google, Facebook, and Twitter. There's a number of ways it can do this; the current draft RFC is here: http://tools.ietf.org/html/rfc5849 . The "Example" section is short and a recommended read. A number of people have tried to implement it in Twisted. AFAICT most of them just use oauth.py. That uses urllib. Basically I guess it just crosses its fingers and hopes that the OAuth API endpoints will always be reachable and responsive. (I have been told this is completely unrealistic.) Thankfully, the OAuth spec is asynchronous in nature. I'm trying to implement OAuth using twisted (specifically twisted.cred and twisted.web) to promote code re-use. In order to do the authentication OAuth relies on redirection (in most use cases, this is HTTP redirection), which would be protocol specific. I'm not sure how twisted.cred fits into this since it appears to expect everything beyond the portal to be protocol-agnostic. I'm not sure what the credentials would be. If I understand correctly the avatar would be the thing that has the token credentials (for those who haven't read the OAuth spec, "token credentials" are an OAuth thing, and not necessarily the credentials in the twisted.cred sense); it represents a single authenticated transaction (which might consist of many authenticated requests). This takes care of steps 6 7 and 8 in http://twistedmatrix.com/documents/current/core/img/cred-login.png. The strange bits start in the CredentialsChecker, since credentials are checked by someone else entirely. I really don't understand the Mind, but it sounds like something that might be required in the context of a three-actor auth system like OAuth. I would be really grateful if someone who actually understood twisted.cred (and hopefully also OAuth) could shed some light on this. Thanks in advance Laurens

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[Twisted-Python] Problem with twistedmatrix.com
by Peter Westlake 05 Jul '10

05 Jul '10

Some of twistedmatrix.com is working, but the top level (http://twistedmatrix.com/) says "Could not connect", and the Subversion repository does the same: svn checkout svn://svn.twistedmatrix.com/svn/Twisted svn: Can't connect to host 'svn.twistedmatrix.com': Connection refused Peter.

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[Twisted-Python] Twisted 10.1.0 release status update
by Jonathan Lange 04 Jul '10

04 Jul '10

Hello everyone, The Twisted 10.1.0 release is now a month overdue. Sorry. We've got a pre-release which appears to be free of critical bugs, and I'm up to step 4 of "How to do a final release" on http://twistedmatrix.com/trac/wiki/ReleaseProcess. My intent is to complete the final steps of the release this weekend. It would be very, very helpful to have someone around who has root on cube and is able to be responsive to requests during a UK afternoon / evening. Twisted prevails, jml

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[Twisted-Python] Twisted 10.1.0 released
by Jonathan Lange 04 Jul '10

04 Jul '10

On behalf of Twisted Matrix Laboratories, I am honored to announce the release of Twisted 10.1.0. Highlights include: * Deferreds now support cancellation * A new "endpoint" interface which can abstractly describe stream transport endpoints such as TCP and SSL * inotify support for Linux, which allows monitoring of file system events. * AMP supports transferring timestamps Note also that this is the *last* supported release of Twisted for Python 2.4 on Windows. For more information, see the NEWS file. It's stable, backwards compatible, well tested and in every way an improvement. Download it now from: http://tmrc.mit.edu/mirror/twisted/Twisted/10.1/Twisted-10.1.0.tar.bz2 http://tmrc.mit.edu/mirror/twisted/Twisted/10.1/Twisted-10.1.0.winxp32-py2.… http://tmrc.mit.edu/mirror/twisted/Twisted/10.1/Twisted-10.1.0.winxp32-py2.… Many thanks to Glyph Lefkowitz, who helped do the release preparation, and the PyCon 2010 sprinters, who did so much of the work for this release. jml

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 04 Jul '10

04 Jul '10

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[Twisted-Python] making Screwtape (Tim Allen) a committer
by Glyph Lefkowitz 02 Jul '10

02 Jul '10

I think we should give screwtape an SVN account and make him an official reviewer. He's been doing a lot of work on the distutils code which would be made easier by that, and he's been doing pretty decent reviews. Thoughts? (Feel free to voice any comments off-list, too.)

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