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pgpverify(8)
NAME
  pgpverify - cryptographically verify Usenet control messages

SYNOPSIS
  pgpverify [ -test ]

DESCRIPTION
  The pgpverify program reads (on standard input) a Usenet control message
  that has been cryptographically signed using the signcontrol program.
  pgpverify then uses the pgp program to determine who signed the control
  message.  If the control message was validly signed, pgpverify outputs (to
  stdout) the User ID of the key ID that signed the message.

OPTIONS
  The ``-test'' flag causes pgpverify to print out the input it is passing to
  pgp (which is a reconstructed version of the input that supposedly created
  the control message) as well as the output of pgp's analysis of the
  message.

EXIT STATUS
  pgpverify returns the follow exit statuses for the following cases:

  0    The control message had a good PGP signature.

  1    The control message had no PGP signature.

  2    The control message had an unknown PGP signature.

  3    The control message had a bad PGP signature.

  255  A problem occurred not directly related to PGP analysis of signature.

AUTHOR
  David C Lawrence <tale@isc.org>

ENVIRONMENT
  pgpverify does not modify or otherwise alter the environment before
  invoking the pgp program.  It is the responsibility of the person who
  installs pgpverify to ensure that when pgp runs, it has the ability to
  locate and read a PGP key file that contains the PGP public keys for the
  appropriate Usenet hierarchy administrators.

SEE ALSO
  pgp(1)

NOTES
  Historically, Usenet news server administrators have configured their news
  servers to automatically honor Usenet control messages based on the
  originator of the control messages and the hierarchies for which the
  control messages applied.  For example, in the past, David C Lawrence
  <tale@uunet.uu.net> always issued control messages for the "Big 8"
  hierarchies (comp, humanities, misc, news, rec, sci, soc, talk).  Usenet
  news administrators would configure their news server software to
  automatically honor newgroup and rmgroup control messages that originated
  from David Lawrence and applied to any of the Big 8 hierarchies.

  Unfortunately, Usenet news articles (including control messages) are
  notoriously easy to forge.  Soon, malicious users realized they could
  create or remove (at least temporarily) any Big 8 newsgroup they wanted by
  simply forging an appropriate control message in David Lawrence's name.  As
  Usenet became more widely used, forgeries became more common.

  The pgpverify program was designed to allow Usenet news administrators to
  configure their servers to cryptographically verify control messages before
  automatically acting on them.	 Under the pgpverify system, a Usenet
  hierarchy maintainer creates a PGP public/private key pair and disseminates
  the public key.  Whenever the hierarchy maintainer issues a control
  message, he uses the signcontrol program to sign the control message with
  the PGP private key.	Usenet news administrators configure their news
  servers to run the pgpverify program on the appropriate control messages,
  and take action based on the PGP key User ID that signed the control
  message, not the name and address that appear in the control message's From
  or Sender headers.

  Thus, using the signcontrol and pgpverify programs appropriately
  essentially eliminates the possibility of malicious users forging Usenet
  control messages that sites will act upon, as such users would have to
  obtain the PGP private key in order to forge a control message that would
  pass the cryptographic verification step.  If the hierarchy administrators
  properly protect their PGP private keys, the only way a malicious user
  could forge a validly-signed control message would be by breaking the RSA
  encryption algorithm, which (at least at this time) is believed to be an
  NP-complete problem.	If this is indeed the case, discovering the PGP
  private key based on the PGP public key is computationally impossible for
  PGP keys of a sufficient bit length.

  <URL:ftp://ftp.isc.org/pub/pgpcontrol/> is where the most recent versions
  of signcontrol and pgpverify live, along with PGP public keys used for
  hierarchy administration.

Index for Section 8

Alphabetical listing for P

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