Mailman 3 April 2010 - Twisted

[Twisted-Python] Network newbie
by Brian Duffy 08 Apr '10

08 Apr '10

I have been wondering how I could develop a python application which would make it easy for users of this application to share small amounts of textual information over the Internet. The information is not confidential but I would like to ensure that it is coming from and generated by the application in question using ssl. I want it to be easy for users of the application to identify and communicate with other users of the application. What type of network am I talking about here? I have plenty of programming experience, but not much network programming experience. Any advice would be appreciated. thanks Brian Duffy -- Duff

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[Twisted-Python] R: Re: smtp-server: issue with checkers.FilePasswordDB and hash
by aleuser＠inwind.it 06 Apr '10

06 Apr '10

First of all, thanks for your answer :-) >Can't say for sure without a full example, but it looks like you are Here the full source code: from twisted.mail import mail, relaymanager from twisted.cred import checkers from twisted.python import log from twisted.application import internet from twisted.application import service import os, md5 SMTP_PORT = 25 QUEUE_PATH = './users_home/insertionQueue' if not os.path.exists(QUEUE_PATH): os.makedirs(QUEUE_PATH) def _hash(name, clearpsw, hashedpsw): return 'aa' return md5.md5(clearpsw).hexdigest() # doesnt' work# smtpusers = checkers.FilePasswordDB('smtppasswords.txt', caseSensitive=True, hash=_hash, cache=True) smtpusers = checkers.FilePasswordDB('smtppasswords.txt', caseSensitive=True, cache=True) mailservice = mail.MailService() mailservice.setQueue(relaymanager.Queue(QUEUE_PATH)) mailservice.smtpPortal.registerChecker(smtpusers) smtpserver = mailservice.getESMTPFactory() application = service.Application("Console SMTP Server") internet.TCPServer(SMTP_PORT, smtpserver).setServiceParent(application) >If you provide a hash function to FilePasswordDB, it only accepts >IUsernamePassword credentials. The hash function is for plaintext I read the source code, I'm agree with this point >If your passwords are already hashed before they are sent to the server >for authentication, then there is no need for a hash function. >FilePasswordDB will accept either IUsernamePassword or >IUsernameHashedPassword credentials. I want to hash the password on the server; can't I? How I can decide to use a simple IUsernamePassword? however If I don't use the hash function the connection still continue to use an IUsernameHashedPassword. Probably the smtp connection is not made for a plain-text password, isn't it? Alessandro

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[Twisted-Python] data update to multiple clients
by Chris Cusack 05 Apr '10

05 Apr '10

Probably another newbie question but after much effort I am not progressing on the following. I am trying to design a system where I have a microprocessor periodically feeding data on a serial connection to a server script. I would then like the server script to notify one or more client scripts of the changed data across a local network. I have tried a few simple tcp server and client script examples which communicate well for a single call but do not seem to suit my application which is not client event driven. I considered having each client connect to the server every ?? seconds to query for new data but there may be a better way. Can anyone suggest a suitable design approach using twisted? Is there any example code available that may be similar. Chris

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[Twisted-Python] FUSE
by Donal McMullan 05 Apr '10

05 Apr '10

I'm interested in doing some FUSE stuff with Twisted, mostly to prototype some ideas for profiling. Can anyone expand on Glyph's comment [1]: 8< - - - - - - - - - - - - - - - - - - - - - - - - - - - - The Python FUSE bindings obscure the issue because, unlike the C libfuse, they assume that your filesystem I/O is blocking, which severely limits the performance of python-based filesystems. (You cannot receive more requests for I/O in your filesystem until the previous one has been completed with the pyfuse bindings, but you can in C.) 8< - - - - - - - - - - - - - - - - - - - - - - - - - - - - I guess I'd like to know before I sink too much time into this, if there's an approach to Fuse/Twisted that would not have this limitation. This is a bit confused by the fact that there are three Fuse/Python bindings that I'm aware of: FusePython, FusePy, and S3QL [2]. http://sourceforge.net/apps/mediawiki/fuse/index.php?title=FusePython http://code.google.com/p/fusepy/ http://code.google.com/p/s3ql/ If you've already been down this road, it'd be good to hear from you. Thanks Donal [1] Glyph's original mail: http://twistedmatrix.com/pipermail/twisted-python/2007-July/015784.html [2] S3QL has its own Python/Fuse bindings, according to this post: http://bugs.python.org/msg98077 ..on this issue: http://bugs.python.org/issue7736

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[Twisted-Python] smtp-server: issue with checkers.FilePasswordDB and hash
by aleuser＠inwind.it 05 Apr '10

05 Apr '10

Hi all, I use FilePasswordDB with a small smtp-server (a very small toy), but when I use the hash function the authentication doesn't work. Here few lines of code: """ def _hash(name, clearpsw, hashedpsw): # a very simple hash function ? return md5.md5(clearpsw).hexdigest() # return 'aa' # doesn't work; password file content is correctly "hashed" smtpusers = checkers.FilePasswordDB('smtppasswords.txt', caseSensitive=True, hash=_hash, cache=True) # work! in the file the passwords are in plain text #smtpusers = checkers.FilePasswordDB('smtppasswords.txt', caseSensitive=True, cache=True) mailservice = mail.MailService() mailservice.setQueue(relaymanager.Queue(QUEUE_PATH)) mailservice.smtpPortal.registerChecker(smtpusers) smtpserver = mailservice.getESMTPFactory() application = service.Application("Console SMTP Server") internet.TCPServer(SMTP_PORT, smtpserver).setServiceParent(application) """ The error is: Failure: twisted.cred.error.UnhandledCredentials: No checker for twisted.cred. credentials.IUsernameHashedPassword Obviously FilePasswordDB doesn't provide that credential when there is the hash function; why smtp connection is hashed and not in plaintext? How can I get it works? I found a similar question, with no answer: http://twistedmatrix.com/pipermail/twisted-python/2006-November/014395.html Thanks Alessandro

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

04 Apr '10

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[Twisted-Python] Noob alert - Looking for a framework for creating a long polling service
by Cedric Dugas 04 Apr '10

04 Apr '10

Hi guys, I am a front-end developer, starting with django with some php in the belt. I am looking for a framework for doing a long polling service where : clients would connect to a soecific 'channel' and wait for a response Where a client admin would push a response only to clients connected to the same channel It's a bit like a chat where everyone listening and only one is talking with multiple channels I am a bit lost in the twisted doc, I know that twisted do a LOT of thing, and was wondering, if twisted is appropriate for this task, and do you have a book to recommend for people like me (by that I mean that I will not be using low level api's) Thank you!

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[Twisted-Python] session management
by Mark 02 Apr '10

02 Apr '10

Greetings, I am new to this list and twisted. I have worked with some systems similar to twisted, notably Apache MINA. I am trying to find out how to set up my server to support sessions for multiple clients. Right now I am simply developing a telnet-like application to learn twisted but cannot figure out how to manage sessions for the remote clients. Thanks, Mark

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[Twisted-Python] Inline Callbacks
by Jason J. W. Williams 02 Apr '10

02 Apr '10

Would it be fair to say that when developing code that utilizes inlineCallbacks, your function is a generator that returns a deferred whose callback is the coroutine that's yielding? -J

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[Twisted-Python] ~twisted-dev on Launchpad will now receive mail about bugs filed on Ubuntu's Twisted
by Jonathan Lange 01 Apr '10

01 Apr '10

Hello all, I've subscribed the Launchpad team https://launchpad.net/~twisted-dev to receive mail about bugs on the "twisted" source package in Ubuntu. It will add a small amount of email traffic to anyone who's a member of that team. However, it will let us know about bugs that Ubuntu users experience that are due to Twisted. I'll gladly unsubscribe the team if folk complain loudly enough. Thanks, jml

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