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PMCHECK(1)             DragonFly General Commands Manual            PMCHECK(1)

NAME
       pmcheck - check veracity and applicability of signatures in news
       articles.

SYNOPSIS
       pmcheck [newsgroups|user] [file]

DESCRIPTION
       Pmcheck accepts an article from the named file (or standard input if
       not specified), and performs certain checks against digital signatures
       present in X-Auth: headers in the news articles. There are two common
       modes of use of pmcheck, and these are described separately for
       simplicity, even though there is considerable ability to mix-and-match.

       The first use is when a person is reading news, and sees an article and
       wishes to check whether the article is an approved posting to a
       moderated newsgroup, or an approved posting from a particular
       individual user. Piping the article through pmcheck will give a list of
       valid signatures (or signatures which couldn't be checked because
       corresponding PGP public keys were unavailable), and of course generate
       error messages for invalid signatures, which indicate either forged or
       altered articles. Any alteration might have been intentional, but bear
       in mind the possibility that an alteration could have been an artifact
       of the news system, despite precautions against this.

       The second use, and the reason for the existence of the PGP Moose
       system, is when an article is automatically checked upon receipt by a
       designated news hub. In this case, a moderated newsgroup or user name
       (represented by an electronic mail address) will be specified, and it
       is considered an error if there is no corresponding X-Auth: header, or
       if for any reason it doesn't check out. Furthermore, there can be a
       configured file which lists pairs of newsgroup/user names, and
       corresponding PGP user IDs who are allowed to authorise such postings.
       Even a valid signature from an individual who is not listed in this
       file will be considered an error. All X-Auth: headers will be checked
       if their newsgroup/user name appears in the checking file, the only way
       in which the argument is special is that such a header for that
       newsgroup or user must appear.  The intention is that any article which
       fails this authentication process will be reported to the user or
       newsgroup moderator(s), and might be automatically cancelled. This is
       to react quickly to spamming attacks on moderated newsgroups.

EXIT STATUS
       Pmcheck returns an exit status of 0 if everything is all right, and
       non-zero otherwise.  In particular, an exit status of 1 means that the
       article was not approved with the PGP Moose when it should have been,
       and a status of 2 is returned for all other authentication problems.

SEE ALSO
       pmapp(1), pmcanon(1) for a description of the fields which go into the
       signature calculation, the PGP User's Manual, the PGP Moose README file
       for an understanding of how it all hangs together.

BUGS
       Currently pmcheck always allows cancel messages to pass, despite the
       fact that pmdaemon always authenticates them. The potential
       consequences of an automated cancellation-war were simply too horrible
       to contemplate.

AUTHOR
       Greg Rose, RoSecure Software.

                                   PGP Moose                        PMCHECK(1)