perl-nocem - A NoCeM-on-spool implementation for INN 2.x
perl-nocem
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.
The
perl-nocem program appends all status messages to
perl-nocem.log in
pathlog if "Sys::Syslog" is not
available; otherwise, and it should normally be the case, the syslog facility
is used. Status messages are then appended to a file usually named
news.notice in
pathlog. (Some logs will be written only if debug
level is set up to be logged via syslog.)
Processing NoCeM notices is easy to set up:
- 1.
- If not already done, install GnuPG, or an equivalent
implementation of the OpenPGP standard, to be able to verify the signature
of NoCeM notices. It will provide the gpg and gpgv programs.
If GnuPG was already installed when INN was configured, then the paths to
these programs were taken into account. Otherwise, you have to set the
$gpg and $gpgv variables in pathlib/perl/INN/Config.pm to the paths
to these programs.
All still active NoCeM issuers use rather modern PGP keys accepted by both
GnuPG 1.x and 2.x versions. It is no longer needed to explicitly use
gpg1 to process NoCeM notices.
- 2.
- Import the keys of the NoCeM issuers you trust in order to
check the authenticity of their notices. You can run the following
command:
gpg --no-default-keyring --allow-non-selfsigned-uid \
--primary-keyring <pathetc>/pgp/ncmring.gpg --no-options \
--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.
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.
- 3.
- Create a nocem.ctl config file in pathetc
indicating the NoCeM issuers and notices you want to follow. This
permission file contains lines like:
[email protected]:spam,site
[email protected]: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. Usually, you just keep the lines
corresponding to the keys previously installed.
You will also find information about that on the web site of The
NoCeM Registry. Note that INN is shipped with an up-to-date
nocem.ctl file already configured with the current NoCeM issuers.
(Only the keys installed at the previous step are not included, so as to
leave you the choice of whom to trust, and download the most recent ones,
in case they have changed.)
- 4.
- 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, the usual groups where notices are sent:
nocem!\
:!*,alt.nocem.misc,news.lists.filters\
:Tc,Wf,Ap:<pathbin>/perl-nocem
with the correct path to perl-nocem, located in <pathbin>.
Then, run "inncheck" to ensure the syntax of the modified
newsfeeds file is correct, and reload it (via "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.
- 5.
- 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.
-
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.
The Subject header field body is not checked for the @@NCM string and there is
no check for the presence of the References header field.
The Newsgroups pseudo header field body is not checked, but this can be done in
"local_want_cancel_id()".
The Hierarchies header field is ignored.
Copyright 2000 by Miquel van Smoorenburg <
[email protected]>.
Copyright 2001 by Marco d'Itri <
[email protected]>.
gpg(1),
gpgv(1),
grephistory(1),
inn.conf(5),
newsfeeds(5),
pgp(1).