iXhash is a plugin for the popular spam filter SpamAssassin.
It computes MD5 checksums of fragments of the body of an e-mail and
compares them to those of know spam. As such it works similar to the
now standard plugins that use the Pyzor, Razor and DCC software
packages external to SpamAssassin. However, with this plugin you are
able to:
- Set up your own spam database from spamtraps you might run (which you cannot do with Razor, as the Razor servers are run by Cloudmark)
- Query different data sources and score them differently (which you cannot do whith Pyzor)
- The original one uses DNS queries to a RBL-like remote server. Currently three different zones are available.
- The MyiXhash-plugin uses the same technique to compute hashes but uses SQL to query a (more or less local) MySQL database.
A server programm written in Perl (hashhack-server.pl) is also available; it can be used to feed a MySQL database that in turn provides either data to the MyiXhash plugin directly or can be used provide DNS services via appropriate tools like MyDNS or RBLDNS
The code can be downloaded via the links at this project's summary page
CREDITS
The iXhash plugin is based on parts of the NiXspam project, a procmail recipe developed by Bert Ungerer of Heise Verlag, Germany. The (German) pages of that project can be reached at http://www.nixspam.org or http://www.heise.de/ix/nixspam/. The procmail code producing the hashes only can be found at ftp://ftp.ix.de/pub/ix/ix_listings/2004/05/checksums.
Parts of the code are based on code submitted via Heise-Forum by 'kungfuhasi' See http://www.heise.de/ix/foren/go.shtml?read=1&msg_id=7246759&forum_id=48292.
Martin Blapp (mb@imp.ch) found and solved a problem occuring on Perl 5.8.7. Thanks a lot!
Further improvements (DNS timeouts) by Dallas Engelken (dallase@uribl.com) - see comments for details.
NB: Although this project is on friendly terms with Bert Ungerer @ Heise Verlag, it should be noted that this project has no connection to Heise itself apart from using the same algorithm to compute hashes and the resulting interoperatibility.
