NAME

Mail::SpamAssassin::Plugin::OpenPGP - A SpamAssassin plugin that validates OpenPGP signed email.

VERSION

Version 1.0.4

SYNOPSIS

Install this module by running:

 cpan Mail::SpamAssassin::Plugin::OpenPGP

Tell SpamAssassin to use it by putting the following (from this module's etc/init_openpgp.pre) in a configuration file

 loadplugin Mail::SpamAssassin::Plugin::OpenPGP

Configure the plugin by putting the following (from this module's etc/26_openpgp.cf) in a configuration file (see http://wiki.apache.org/spamassassin/WhereDoLocalSettingsGo)

 ifplugin Mail::SpamAssassin::Plugin::OpenPGP
 
 rawbody   OPENPGP_SIGNED     eval:check_openpgp_signed()
 describe OPENPGP_SIGNED     OpenPGP: message body is signed
 
 rawbody   OPENPGP_ENCRYPTED     eval:check_openpgp_encrypted()
 describe OPENPGP_ENCRYPTED     OpenPGP: message body is encrypted
 
 rawbody   OPENPGP_SIGNED_GOOD     eval:check_openpgp_signed_good()
 describe OPENPGP_SIGNED_GOOD     OpenPGP: message body is signed with a valid signature
 tflags OPENPGP_SIGNED_GOOD nice
 
 rawbody   OPENPGP_SIGNED_BAD     eval:check_openpgp_signed_bad()
 describe OPENPGP_SIGNED_BAD     OpenPGP: message body is signed but the signature is invalid, or doesn't match with email's date or sender
 
 endif   # Mail::SpamAssassin::Plugin::OpenPGP

Set up some rules to your liking, for example:

 score OPENPGP_SIGNED -1
 # this would total to -2
 score OPENPGP_SIGNED_GOOD -1
 # this would total to 0
 score OPENPGP_SIGNED_BAD 1

DESCRIPTION

This uses Mail::GPG which uses GnuPG::Interface which uses Gnu Privacy Guard via IPC.

Make sure the homedir you use for gnupg has a gpg.conf with something like the following in it, so that it will automatically fetch public keys. And make sure that the directory & files are only readable by owner (a gpg security requirement).

 keyserver-options auto-key-retrieve timeout=5
 # any keyserver will do
 keyserver  x-hkp://random.sks.keyserver.penguin.de

If a public key cannot be retrieved, the email will be marked as SIGNED but neither GOOD nor BAD. To ensure that your local public keys don't get out of date, you should probably set up a scheduled job to delete pubring.gpg regularly

For project information, see http://konfidi.org

USER SETTINGS

 gpg_executable /path/to/gpg
 gpg_homedir /var/foo/gpg-homedir-for-spamassassin
 openpgp_add_header_fingerprint 1 # default 1 (true)
 openpgp_add_header_failure_info 0 # default 1 (true)

The OpenPGP headers are never added to emails without a signature.

TAGS

The following per-message SpamAssassin "tags" are set.

openpgp_checked

Set to 1 after the email has been checked for an OpenPGP signature

openpgp_signed

Set to 1 if the email has an OpenPGP signature

openpgp_signed_good

Set to 1 if the email has a "good" OpenPGP signature

openpgp_signed_bad

Set to 1 if the email has a "bad" OpenPGP signature

openpgp_encrypted

Set to 1 if the email is encrypted with OpenPGP

openpgp_fingerprint

Set to the OpenPGP fingerprint from the signature

AUTHOR

Dave Brondsema, <dave at brondsema.net>

BUGS

If only part of a PGP/MIME message is signed (for example, a mailing list added a footer outside of the main content & signature) then it is not considered signed. If any part of a message is signed inline, it is considered signed. A future version will probably use OPENPGP_PART_SIGNED, and have checks to verify that the unsigned part is at the end and that the signed part is not very short (to prevent spammers from having a small signed part accompanied by a large spammy part).

Please report any bugs or feature requests to bug-mail-spamassassin-plugin-OpenPGP at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Mail-SpamAssassin-Plugin-OpenPGP. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Mail::SpamAssassin::Plugin::OpenPGP

You can also look for information at:

ACKNOWLEDGEMENTS

COPYRIGHT & LICENSE

Copyright 2006 Dave Brondsema, all rights reserved.

This program is released under the following license: Apache License, Version 2.0