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 The perl-nocem program appends all status messages to perl-nocem.log in
27 pathlog if "Sys::Syslog" is not available; otherwise, and it should
28 normally be the case, the syslog facility is used. Status messages are
29 then appended to a file usually named news.notice in pathlog. (Some
30 logs will be written only if debug level is set up to be logged via
31 syslog.)
32 Processing NoCeM notices is easy to set up:
34 1. If not already done, install GnuPG, or an equivalent implementation
36 of the OpenPGP standard, to be able to verify the signature of
37 NoCeM notices. It will provide the gpg and gpgv programs. If
38 GnuPG was already installed when INN was configured, then the paths
39 to these programs were taken into account. Otherwise, you have to
40 set the $gpg and $gpgv variables in pathlib/perl/INN/Config.pm to
41 the paths to these programs.
42 All still active NoCeM issuers use rather modern PGP keys accepted
44 by both GnuPG 1.x and 2.x versions. It is no longer needed to
45 explicitly use gpg1 to process NoCeM notices.
46 2. Import the keys of the NoCeM issuers you trust in order to check
48 the authenticity of their notices. You can run the following
49 command:
50 gpg --no-default-keyring --allow-non-selfsigned-uid \
52 --primary-keyring <pathetc>/pgp/ncmring.gpg --no-options \
53 --no-permission-warning --batch --import <key-file>
54 chmod 644 <pathetc>/pgp/ncmring.gpg
55 where <pathetc> is the value of the pathetc parameter set in
57 inn.conf and <key-file> the file containing the key(s) to import.
58 The keyring must be located in <pathetc>/pgp/ncmring.gpg; you only
59 have to create the directory <pathetc>/pgp before using gpg (it
60 will automatically generate the ncmring.gpg file) and make sure the
61 news user can read this file, once generated.
62 The keys of NoCeM issuers can be found in the web site of The NoCeM
64 Registry: <http://rosalind.home.xs4all.nl/nocemreg/nocemreg.html>.
65 You can even download there a unique file which contains all the
66 keys.
67 3. Create a nocem.ctl config file in pathetc indicating the NoCeM
69 issuers and notices you want to follow. This permission file
70 contains lines like:
71 bleachbot@httrack.com:spam,site
73 pgpmoose@killfile.org:pgpmoose-forged-moderation
74 This will remove all articles for which the issuer (first part of
76 the line, before the colon ":") has issued NoCeM notices
77 corresponding to the criteria specified after the colon. Usually,
78 you just keep the lines corresponding to the keys previously
79 installed.
80 You will also find information about that on the web site of The
82 NoCeM Registry. Note that INN is shipped with an up-to-date
83 nocem.ctl file already configured with the current NoCeM issuers.
84 (Only the keys installed at the previous step are not included, so
85 as to leave you the choice of whom to trust, and download the most
86 recent ones, in case they have changed.)
87 4. Add to the newsfeeds file an entry like this one in order to feed
89 perl-nocem the NoCeM notices posted to alt.nocem.misc and
90 news.lists.filters, the usual groups where notices are sent:
91 nocem!\
93 :!*,alt.nocem.misc,news.lists.filters\
94 :Tc,Wf,Ap:<pathbin>/perl-nocem
95 with the correct path to perl-nocem, located in <pathbin>. Then,
97 run "inncheck" to ensure the syntax of the modified newsfeeds file
98 is correct, and reload it (via "ctlinnd reload newsfeeds 'NoCeM
99 channel feed'").
100 Note that you should at least carry news.lists.filters on your news
102 server (or other newsgroups where NoCeM notices are sent) if you
103 wish to process them.
104 5. Everything should now work. However, do not hesitate to manually
106 test perl-nocem with a NoCeM notice, using:
107 grephistory '<Message-ID>' | perl-nocem
109 Indeed, perl-nocem expects tokens on its standard input, and
111 grephistory can easily give it the token of a known article, thanks
112 to its Message-ID.
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115 pathbin/perl-nocem
116 The Perl script itself used to process NoCeM notices.
117 pathetc/nocem.ctl
119 The configuration file which specifies the NoCeM notices to be
120 processed.
121 pathetc/pgp/ncmring.gpg
123 The keyring which contains the public keys of trusted NoCeM
124 issuers.
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127 The Subject header field body is not checked for the @@NCM string and
128 there is no check for the presence of the References header field.
129 The Newsgroups pseudo header field body is not checked, but this can be
131 done in "local_want_cancel_id()".
132 The Hierarchies header field is ignored.
134
136 Copyright 2000 by Miquel van Smoorenburg <miquels@cistron.nl>.
137 Copyright 2001 by Marco d'Itri <md@linux.it>.
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141 gpg(1), gpgv(1), grephistory(1), inn.conf(5), newsfeeds(5), pgp(1).
142INN 2.7.0 2022-07-10 PERL-NOCEM(8)