Folks,
just uploaded a new version of the iXhash plugin to http://ixhash.sf.net.
For those that don't know what the plugin is good for: 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 plugins that use the
Pyzor, Razor and DCC software packages.
The plugins algorithm is based on parts of the 'NiX Spam' project by
Bert Ungerer of Heise Verlag, Germany. See http://www.nixspam.org for
more info on that.
Currently there are four DNS zones that can be queried by the plugin:
- ix.dnsbl.manitu.net; See http://www.dnsbl.manitu.net. This zone is fed
by contributors to the NiX Spam project.
- generic.ixhash.net; run by me - see www.ixhash.net. This is where
diverse spam feed donations end up
- ctyme.ixhash.net; spam data provided by Marc Perkel
- hosteurope.ixhash.net Zone provided by Host Europe GmbH, Cologne,
Germany. <http://www.hosteurope.de/produkte/Webhosting-Domains-E-Shops>
There have been quite a few changes. The most important ones would be
- Implemented a check to see if the returned IP fits the 127.0.0.0/8
subnet. This should prevent problems with OpenDSN and other DNS
providers that somehow, sometimes, for some reason return other IPs
- Implemented the ability to store a hash with the repective mail's
metadata (Option 'use_ixhash_cache'). Other iXhash tests can then re-use
the already computed hashes.
- Implemented a way to have the plugin compute the hashes via the local
system's 'tr' and 'md5sum' commands. This is what the original,
procmail-based NiX Spam code does and should be somewhat more
compatible. If you decide to set 'xhash_pureperl' to '0', you can use
'ixhash_tr_path' and 'ixhash_md5sum_path' to specify which binaries to
use. If you don't, SpamAssassin will use what it can find.
- Revamped some regular expressions to
a.) actually have them do what they should do and
b.) circumvent problems with some Perl versions/releases.
Thanks, Alex, Per, Frank and Bert for helping me with testing and
valuable input.
Special thanks to Marc Perkel - for supporting my little project with
data, computing ressources and valuable time - and also to Host Europe
GmbH and Jan Doberstein who graciously support the iXhash project by
donating server and network ressources.
Dirk
