1PERL-NOCEM(8) InterNetNews Documentation PERL-NOCEM(8)
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6 perl-nocem - A NoCeM-on-spool implementation for INN 2.x
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9 perl-nocem
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12 NoCeM, which is pronounced No See 'Em, is a protocol enabling
13 authenticated third-parties to issue notices which can be used to
14 cancel unwanted articles (like spam and articles in moderated
15 newsgroups which were not approved by their moderators). It can also
16 be used by readers as a third-party killfile. It is intended to
17 eventually replace the protocol for third-party cancel messages.
18 perl-nocem processes third-party, PGP-signed article cancellation
20 notices. It is possible not to honour all NoCeM notices but only those
21 which are sent by people whom you trust (that is to say if you trust
22 the PGP key they use to sign their NoCeM notices). Indeed, it is up to
23 you to decide whether you wish to honour their notices, depending on
24 the criteria they use.
25 Processing NoCeM notices is easy to set up:
27 1. If not already done, install GnuPG, or an equivalent implementation
29 of the OpenPGP standard, to be able to verify the signature of
30 NoCeM notices. It will provide the gpg and gpgv programs. If
31 GnuPG was already installed when INN was configured, then the paths
32 to these programs were taken into account. Otherwise, you have to
33 set the $gpg and $gpgv variables in pathlib/perl/INN/Config.pm to
34 the paths to these programs.
35 All still active NoCeM issuers use rather modern PGP keys accepted
37 by both GnuPG 1.x and 2.x versions. It is no longer needed to
38 explicitly use gpg1 to process NoCeM notices.
39 2. Import the keys of the NoCeM issuers you trust in order to check
41 the authenticity of their notices. You can run the following
42 command:
43 gpg --no-default-keyring --allow-non-selfsigned-uid \
45 --primary-keyring <pathetc>/pgp/ncmring.gpg --no-options \
46 --no-permission-warning --batch --import <key-file>
47 chmod 644 <pathetc>/pgp/ncmring.gpg
48 where <pathetc> is the value of the pathetc parameter set in
50 inn.conf and <key-file> the file containing the key(s) to import.
51 The keyring must be located in <pathetc>/pgp/ncmring.gpg; you only
52 have to create the directory <pathetc>/pgp before using gpg (it
53 will automatically generate the ncmring.gpg file) and make sure the
54 news user can read this file, once generated.
55 The keys of NoCeM issuers can be found in the web site of The NoCeM
57 Registry: <http://rosalind.home.xs4all.nl/nocemreg/nocemreg.html>.
58 You can even download there a unique file which contains all the
59 keys.
60 3. Create a nocem.ctl config file in pathetc indicating the NoCeM
62 issuers and notices you want to follow. This permission file
63 contains lines like:
64 bleachbot@httrack.com:spam,site
66 pgpmoose@killfile.org:pgpmoose-forged-moderation
67 This will remove all articles for which the issuer (first part of
69 the line, before the colon ":") has issued NoCeM notices
70 corresponding to the criteria specified after the colon. Usually,
71 you just keep the lines corresponding to the keys previously
72 installed.
73 You will also find information about that on the web site of The
75 NoCeM Registry. Note that INN is shipped with an up-to-date
76 nocem.ctl file already configured with the current NoCeM issuers.
77 (Only the keys installed at the previous step are not included, so
78 as to leave you the choice of whom to trust, and download the most
79 recent ones, in case they have changed.)
80 4. Add to the newsfeeds file an entry like this one in order to feed
82 perl-nocem the NoCeM notices posted to alt.nocem.misc and
83 news.lists.filters, the usual groups where notices are sent:
84 nocem!\
86 :!*,alt.nocem.misc,news.lists.filters\
87 :Tc,Wf,Ap:<pathbin>/perl-nocem
88 with the correct path to perl-nocem, located in <pathbin>. Then,
90 run "inncheck" to ensure the syntax of the modified newsfeeds file
91 is correct, and reload it (via "ctlinnd reload newsfeeds 'NoCeM
92 channel feed'").
93 Note that you should at least carry news.lists.filters on your news
95 server (or other newsgroups where NoCeM notices are sent) if you
96 wish to process them.
97 5. Everything should now work. However, do not hesitate to manually
99 test perl-nocem with a NoCeM notice, using:
100 grephistory '<Message-ID>' | perl-nocem
102 Indeed, perl-nocem expects tokens on its standard input, and
104 grephistory can easily give it the token of a known article, thanks
105 to its Message-ID.
106 When you have verified that everything works, you can eventually turn
108 off regular spam cancels, if you want, not processing any longer
109 cancels containing "cyberspam" in the Path: header (see the
110 refusecybercancels parameter in inn.conf).
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113 pathbin/perl-nocem
114 The Perl script itself used to process NoCeM notices.
115 pathetc/nocem.ctl
117 The configuration file which specifies the NoCeM notices to be
118 processed.
119 pathetc/pgp/ncmring.gpg
121 The keyring which contains the public keys of trusted NoCeM
122 issuers.
123
125 The Subject header field body is not checked for the @@NCM string and
126 there is no check for the presence of the References header field.
127 The Newsgroups pseudo header field body is not checked, but this can be
129 done in "local_want_cancel_id()".
130 The Hierarchies: header is ignored.
132
134 Copyright 2000 by Miquel van Smoorenburg <miquels@cistron.nl>.
135 Copyright 2001 by Marco d'Itri <md@linux.it>.
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139 gpg(1), gpgv(1), grephistory(1), inn.conf(5), newsfeeds(5), pgp(1).
140INN 2.6.5 2022-02-18 PERL-NOCEM(8)