Mailman 3 June 2003 - Twisted

[Twisted-Python] Re: [Twisted-commits] explanation of () for anonymity
by Jp Calderone June 21, 2003

June 21, 2003

On Mon, Jun 16, 2003 at 05:57:16AM -0500, glyph CVS wrote: > Modified files: > Twisted/twisted/cred/checkers.py 1.2 1.3 > > Log message: > explanation of () for anonymity > Might an instance of object be a better value for ANONYMOUS? It should be even harder to use this by accident (though I admit I don't see any way to accidentally enter an empty tuple). Jp -- #!/bin/bash ( LIST=(~/.sigs/*.sig) cat ${LIST[$(($RANDOM % ${#LIST[*]}))]} echo -- $'\n' `uptime | … [View More]

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[Twisted-Python] Allow static.Data to be at the root
by Matthias Urlichs June 21, 2003

June 21, 2003

Here's a small patch to allow a twisted.web.static.Data element at the root of your web space. diff -Nru a/twisted/web/static.py b/twisted/web/static.py --- a/twisted/web/static.py Tue May 13 10:22:32 2003 +++ b/twisted/web/static.py Tue May 13 10:22:32 2003 @@ -59,6 +59,12 @@ request.setHeader("content-length", len(self.data)) return '' return self.data + + def getChild(self,path,request): + """Return myself if I am the root.""" + if path =… [View More]

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[Twisted-Python] Fair warning: case-insensitive attributes
by Cory Dodt June 20, 2003

June 20, 2003

Since this could be both a very useful and a very harmful change, I'm posting a set of fairly short diffs to tm.com: http://twistedmatrix.com/users/moonfallen/diffs.txt If anyone thinks this patch will slow things down (possible) or break stuff (unlikely; current tests pass), I want to know that. Of course there are new tests to go with it: http://twistedmatrix.com/users/moonfallen/test_diffs.txt In particular, Woven appears to be unaffected. If I don't get any significant backlash … [View More]

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[Twisted-Python] Simplifying database access in Twisted
by Thomas Weholt June 20, 2003

June 20, 2003

Just read thru http://www.twistedmatrix.com/documents/howto/enterprise and tried to fit the code to my needs, but ... this seems way too complicated. All I want is to execute a SQL-query and do something similar to fetchone or fetchall etc. in the DB-API 2.0 spec. I don't want to be forced to write classes and callbacks etc. just for a simple list of tuples or something returned from a SQL-query. Is there no other way to do simple database access in Twisted? Something more like the DB-API 2.0? … [View More]

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[Twisted-Python] A fake SMTP server
by Grzegorz Adam Hankiewicz June 20, 2003

June 20, 2003

Hi. I've written a small script which implements a very basic dummy SMTP server. It only listens to email and dumps the contents on the screen. I needed it for debugging mail functions at work, where touching the server SMTP is not allowed/dangerous. Maybe somebody else finds it useful. http://gradha.sdf-eu.org/program/fake_SMTP_server-0.1.0.tar.gz -- Grzegorz Adam Hankiewicz, gradha(a)efaber.net. Tel: +34-94-472 35 89. eFaber SL, Maria Diaz de Haro, 68, 2 http://www.efaber.net/… [View More]

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[Twisted-Python] Python 2.3 logging package and Twisted...
by Stuart Hungerford June 19, 2003

June 19, 2003

Hi all, As part of the Python 2.3 releases, the standard library now includes a logging module. In applications using Twisted.web is writing logs with this new module the kind of operation that would need to be done in a deferred? I understand there's also twisted.python.log, but the issue comes up for applications being moved to Twisted that already use external logging libraries. Cheers, Stu -- :: Stuart Hungerford (stuart.hungerford(a)anu.edu.au) :: ANU Internet Futures Group

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[Twisted-Python] Re: Switch to a different uid/gid after binding reserved ports (G
by W.J. June 19, 2003

June 19, 2003

> I have now had a chance to test this on HP-UX11i and have discovered a > problem. > > The code for Application.setUID() calls os.getgid() expecting it to > return 0 Why on earth would you want to check or enforce someone is in group 0? Being in group 0 doesn't have any 'magic' like uid 0 has, well, it might have on some operating systems, but it's not a portable way. Some unices don't even have a special *user* ID 0 but have security based on process privileges. You … [View More]

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Re: Re: [Twisted-Python] Custom webserver
by Vijay Rao June 19, 2003

June 19, 2003

At 06:34 16/06/2003 -0500, you wrote: >Message: 9 >Date: Mon, 16 Jun 2003 10:03:52 +0300 >From: Tommi Virtanen <tv(a)twistedmatrix.com> >To: twisted-python(a)twistedmatrix.com >Subject: Re: [Twisted-Python] Custom webserver >Reply-To: twisted-python(a)twistedmatrix.com > >On Mon, Jun 16, 2003 at 09:57:13AM +0530, Vijay Rao wrote: > > I am trying to use twisted as a webserver that serves files only for > > requests from the localhost ie the desktop on … [View More]

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[Twisted-Python] 1.0.6alpha3
by Christopher Armstrong June 19, 2003

June 19, 2003

1.0.6alpha3 is out there, and it's got new HTTP timeout code activated, thanks to Jp Calderone. I've deployed it on pyramid, and hopefully we won't be having any more downtime due to FD "leakage". 1.0.6 final should be out by the end of the month. -- Twisted | Christopher Armstrong: International Man of Twistery Radix | Release Manager, Twisted Project ---------+ http://twistedmatrix.com/users/radix.twistd/

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[Twisted-Python] Lies, Damn Lies, and Stable Interfaces
by Glyph Lefkowitz June 19, 2003

June 19, 2003

There are some new modules in CVS right now, and I would like some feedback on them. The modules in question are a sketch of The Wave of the Future of authentication in Twisted, A.K.A. "New Cred". A good place to start looking is sandbox/webhappyrealm.py Unfortunately, this sets a bad precedent, since old cred was "semi-stable". However, I think that the break with declared stability is a small price to pay for the _VASTLY_ improved interfaces which this package provides. Since not … [View More]too many people were using the old cred deeply, and the new interfaces are much smaller, hopefully we can migrate to the new code as quickly as possible. Of course, no new Twisted functionality would be complete without a byzantine new set of terms. In this case, the terms are hopefully more descriptive and more memorable; as a bonus, they do not conflict with the old names, so we can keep both versions of cred on-line until such time as the deprecation warnings can be resolved. This message is primarily about those new names. I hope that this provides enough fodder for someone with more time to produce a nice-looking HOWTO. Without further ado, here are the new words you need to integrate into your basal nervous system: ############################# Portal ====== This is the ineffable mystery at the core of login. There is one concrete implementation of Portal, and no interface - it does a very simple task. A Portal associates one (1) Realm with a collection of CredentialChecker instances. (More on those later.) The closest analogue of this in Old Cred was the Authorizer. If you are writing a protocol that needs to authenticate against something, you will need a reference to a Portal, and to nothing else. This has only 2 methods - login(credentials, mind, *interfaces) The docstring is quite expansive (see twisted.cred.portal), but in brief, this is what you call when you need to call in order to connect a user to the system. The result is a deferred which fires a tuple of: - interface (which was one of the interfaces passed in the *interfaces tuple) - an object that implements that interface (an Aspect of an Avatar) - logout, a 0-argument callable which disconnects the connection that was established by this call to login registerChecker(checker, *credentialInterfaces) which adds a CredentialChecker to the portal. Mind ==== Masters of Perspective Broker already know this object as the ill-named "client object". There is no "mind" class, or even interface, but it is an object which serves an important role - any notifications which are to be relayed to an authenticated client are passed through a 'mind'. The name may seem rather unusual, but considering that a Mind is representative of the entity on the "other end" of a network connection that is both receiving updates and issuing commands, I believe it is appropriate. Although many protocols will not use this, it serves an important role. It is provided as an argument both to the Portal and to the Realm, although a CredentialChecker should interact with a client program exclusively through a Credentials instance. Unlike the original Perspective Broker "client object", a Mind's implementation is most often dictated by the protocol that is connecting rather than the Realm. A Realm which requires a particular interface to issue notifications will need to wrap the Protocol's mind implementation with an adapter in order to get one that conforms to its expected interface - however, Perspective Broker will likely continue to use the model where the client object has a pre-specified remote interface. (If you don't quite understand this, it's fine. It's hard to explain, and it's not used in simple usages of cred, so feel free to pass None until you find yourself requiring something like this.) CredentialChecker ================= This is an object which resolves some Credentials to an avatar ID. Some examples of CredentialChecker implementations would be: InMemoryUsernamePassword, ApacheStyleHTAccessFile, UNIXPasswordDatabase, SSHPublicKeyChecker. A credential checker stipulates some requirements of the credentials it can check by specifying a credentialInterfaces attribute, which is a list of interfaces. Credentials passed to its requestAvatarId method must implement one of those interfaces. For the most part, these things will just check usernames and passwords and produce the username as the result, but hopefully we will be seeing some public-key, challenge-response, and certificate based credential checker mechanisms soon. (If somebody were to write an ActiveDirectory-compatible LDAP login, they would be my best friend for EVER.) A credential checker should raise an error if it cannot authenticate the user, and return '' for anonymous access. Credentials =========== Oddly enough, this represents some credentials that the user presents. Usually this will just be a small static blob of data, but in some cases it will actually be an object connected to a network protocol. For example, a username/password pair is static, but a challenge/response server is an active state-machine that will require several method calls in order to determine a result. Realm ===== A realm is an interface which connects your universe of "business objects" to the authentication system. This is similar to the Old Cred "Service", but the name "Service" will be phased out when referring to cred - another planned refactoring is to move twisted.internet.app.ApplicationService into its own module and more heavily emphasize its use in start-up and shut-down. IRealm is another one-method interface: requestAvatar(avatarId, mind, *interfaces) This method will typically be called from 'Portal.login'. The avatarId is the one returned by a CredentialChecker. The important thing to realize about this method is that if it is being called, _the user has already authenticated_. Therefore, if possible, the Realm should create a new user if one does not already exist whenever possible. Of course, sometimes this will be impossible without more information, and that is the case that the interfaces argument is for. Some protocols can only accept a fixed set of interfaces. However, others (most notably PB) can deal with more arbitrary data being returned. An online game may call Portal.login with: login(PBChallengeResponse(...), clientSideThingy, IServerPlayerInWorld, IUserChooser, ICharacterCreationThing) This specifies that the client would most prefer a player in the world, but, failing that, a UserChooser (selection interface for a second step to get a PlayerInWorld) or a CharacterCreationThing (interface to create a new character in the world before returning it) would be acceptable. Since requestAvatar should be called from a Deferred callback, it may return a Deferred or a synchronous result. At the moment, there is only an interface for the Realm. However, it is expected that a utility class will be written in the near future to facilitate log-in methods, a re-directing method similar to "Perspective.attached" for Avatars, and at least somewhat automated compositing of Realms. However, in writing the code for cred and guard, there has been no need for such a thing yet. Avatar ====== This object has the dubious distinction of appearing nowhere in the code; in fact, very few things will ever touch an actual Avatar, and it is not clear that it will have an interface. However, _aspects_ of an avatar are returned in deferreds from the above methods, which is to say, things that implement particular interfaces which communicate with various protocols that may access your Realm. This is (hopefully, obviously) similar to a 'Perspective'. However, an Avatar separates 2 concerns which were muddied previously - _access_ to a realm and _storage of user data_ within a realm. The avatar itself stores the data, and the aspects interface to it. The avatar itself may of course implement its own aspects, but it is suggested in most cases to register adapters that do this. (Perspective Broker will keep its name, because the Avatar Aspect that communicates with the remote object protocol will still be called a Perspective.) ############################# While it's understandable to want to wait for this interface to fully stabilize, we suggest that you start porting code to it _now_, especially if you're already tracking CVS. The old cred was, through the continued efforts of many developers, experimentally determined to be a piece of crap. I humbly suggest that this interface is not only not a piece of crap, but totally awesome, and actually usable in real applications. Not only is it a vastly better design, it makes use of Deferreds in such a way that it is almost effortless to provide or manipulate an implementation of one of these interfaces. (As a yardstick, the code for woven.guard was 30% shorter and the example was almost unmeasureably shorter - sandbox/webhappyrealm.py is already doing things that were impossible under the old model.) I hope this explanation was helpful. Please give feedback. [View Less]

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