perl-nocem processes third-party, PGP-signed article cancellation notices. It is possible not to honour all NoCeM notices but only those which are sent by people whom you trust (that is to say if you trust the PGP key they use to sign their NoCeM notices). Indeed, it is up to you to decide whether you wish to honour their notices, depending on the criteria they use.
Processing NoCeM notices is easy to set up:
gpg --no-default-keyring --primary-keyring=/etc/news/pgp/ncmring.gpg \ --no-options --allow-non-selfsigned-uid --no-permission-warning \ --batch --import <key-file>
where <pathetc> is the value of the pathetc parameter set in inn.conf and <key-file> the file containing the key(s) to import. The keyring must be located in <pathetc>/pgp/ncmring.gpg; you only have to create the directory <pathetc>/pgp before using gpg (it will automatically generate the ncmring.gpg file). For old PGP-generated keys, you may have to use --allow-non-selfsigned-uid if they are not properly self-signed, but anyone creating a key really should self-sign the key. Current PGP implementations do this automatically.
The keys of NoCeM issuers can be found in the web site of The NoCeM Registry: <http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html>. You can even download there a unique file which contains all the keys.
This will remove all articles for which the issuer (first part of the line, before the colon ":") has issued NoCeM notices corresponding to the criteria specified after the colon.
You will also find information about that on the web site of The NoCeM Registry.
nocem!\ :!*,alt.nocem.misc,news.lists.filters\ :Tc,Wf,Ap:<pathbin>/perl-nocem
with the correct path to perl-nocem, located in <pathbin>. Then, reload the newsfeeds file ("ctlinnd reload newsfeeds 'NoCeM channel feed'").
Note that you should at least carry news.lists.filters on your news server (or other newsgroups where NoCeM notices are sent) if you wish to process them.
grephistory '<Message-ID>' | perl-nocem
Indeed, perl-nocem expects tokens on its standard input, and grephistory can easily give it the token of a known article, thanks to its Message-ID.
When you have verified that everything works, you can eventually turn off regular spam cancels, if you want, not processing any longer cancels containing "cyberspam" in the Path: header (see the refusecybercancels parameter in inn.conf).
The Newsgroups: pseudo header is not checked, but this can be done in local_want_cancel_id().
The Hierarchies: header is ignored.
Copyright 2001 by Marco d'Itri <firstname.lastname@example.org>.
$Id: perl-nocem.in 8539 2009-06-28 10:01:24Z iulius $