1PERL-NOCEM(8)             InterNetNews Documentation             PERL-NOCEM(8)
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NAME

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

9       perl-nocem
10

DESCRIPTION

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
19       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
26       Processing NoCeM notices is easy to set up:
27
28       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
36           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
40       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:
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44               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
49           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
56           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
61       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:
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65               bleachbot@httrack.com:spam,site
66               pgpmoose@killfile.org:pgpmoose-forged-moderation
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68           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
74           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
81       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:
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85               nocem!\
86                   :!*,alt.nocem.misc,news.lists.filters\
87                   :Tc,Wf,Ap:<pathbin>/perl-nocem
88
89           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
94           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
98       5.  Everything should now work.  However, do not hesitate to manually
99           test perl-nocem with a NoCeM notice, using:
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101               grephistory '<Message-ID>' | perl-nocem
102
103           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
107       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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FILES

113       pathbin/perl-nocem
114           The Perl script itself used to process NoCeM notices.
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116       pathetc/nocem.ctl
117           The configuration file which specifies the NoCeM notices to be
118           processed.
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120       pathetc/pgp/ncmring.gpg
121           The keyring which contains the public keys of trusted NoCeM
122           issuers.
123

BUGS

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.
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128       The Newsgroups pseudo header field body is not checked, but this can be
129       done in "local_want_cancel_id()".
130
131       The Hierarchies: header is ignored.
132

HISTORY

134       Copyright 2000 by Miquel van Smoorenburg <miquels@cistron.nl>.
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136       Copyright 2001 by Marco d'Itri <md@linux.it>.
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SEE ALSO

139       gpg(1), gpgv(1), grephistory(1), inn.conf(5), newsfeeds(5), pgp(1).
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143INN 2.6.5                         2022-02-18                     PERL-NOCEM(8)
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