Ubuntu Manpage: perl-nocem - A NoCeM-on-spool implementation for INN 2.x

NAME

       perl-nocem - A NoCeM-on-spool implementation for INN 2.x

SYNOPSIS

       perl-nocem

DESCRIPTION

NoCeM, which is pronounced No See 'Em, is a protocol enabling authenticated third-parties
to issue notices which can be used to cancel unwanted articles (like spam and articles in
moderated newsgroups which were not approved by their moderators). It can also be used by
readers as a third-party killfile. It is intended to eventually replace the protocol for
third-party cancel messages.

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:

1. Import the keys of the NoCeM issuers you trust in order to check the authenticity of
their notices. You can do:

gpg1 --no-default-keyring --primary-keyring <pathetc>/pgp/ncmring.gpg \
--no-options --allow-non-selfsigned-uid --no-permission-warning \
--batch --import <key-file>
chmod 644 <pathetc>/pgp/ncmring.gpg

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) and make sure the news
user can read this file, once generated.

As a few NoCeM issuers are still using old PGP-generated keys, you may have to use
gpg1 with various legacy options in command-line (like in the example above) instead
of more recent versions of gpg that no longer accept such keys.

The keys of NoCeM issuers can be found in the web site of The NoCeM Registry:
<http://rosalind.home.xs4all.nl/nocemreg/nocemreg.html>. You can even download there
a unique file which contains all the keys.

2. Create a nocem.ctl config file in pathetc indicating the NoCeM issuers and notices you
want to follow. This permission file contains lines like:

bleachbot@httrack.com:spam,site
pgpmoose@killfile.org:pgpmoose-forged-moderation

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.

3. Add to the newsfeeds file an entry like this one in order to feed perl-nocem the NoCeM
notices posted to alt.nocem.misc and news.lists.filters:

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.

4. Everything should now work. However, do not hesitate to manually test perl-nocem with
a NoCeM notice, using:

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).

FILES

       pathbin/perl-nocem
           The Perl script itself used to process NoCeM notices.

       pathetc/nocem.ctl
           The configuration file which specifies the NoCeM notices to be processed.

       pathetc/pgp/ncmring.gpg
           The keyring which contains the public keys of trusted NoCeM issuers.

BUGS

       The Subject: header is not checked for the @@NCM string and there is no check for the
       presence of the References: header.

       The Newsgroups: pseudo header is not checked, but this can be done in
       local_want_cancel_id().

       The Hierarchies: header is ignored.

HISTORY