NAME

       Mail::DKIM::SignerPolicy - determines signing parameters for a message

DESCRIPTION

       A "signer policy" is an object, class, or function used by Mail::DKIM::Signer to determine
       what signatures to add to the current message. To take advantage of signer policies,
       create your own Perl class that extends the Mail::DKIM::SignerPolicy class.  The only
       method you need to implement is the apply() method.

       The apply() method takes as a parameter the Mail::DKIM::Signer object.  Using this object,
       it can determine some properties of the message (e.g.  what the From: address or Sender:
       address is). Then it sets various signer properties as desired. The apply() method should
       return a nonzero value if the message should be signed. If a false value is returned, then
       the message is "skipped" (i.e. not signed).

       Here is an example of a policy that always returns the same values:

         package MySignerPolicy;
         use base "Mail::DKIM::SignerPolicy";

         sub apply
         {
             my $self = shift;
             my $signer = shift;

             $signer->algorithm("rsa-sha1");
             $signer->method("relaxed");
             $signer->domain("example.org");
             $signer->selector("selector1");
             $signer->key_file("private.key");

             return 1;
         }

       To use this policy, simply specify the name of the class as the Policy parameter...

         my $dkim = Mail::DKIM::Signer->new(
                         Policy => "MySignerPolicy",
                    );

ADVANCED

       You can also have the policy actually build the signature for the Signer to use. To do
       this, call the signer's add_signature() method from within your apply() callback. E.g.,

         sub apply
         {
             my $self = shift;
             my $signer = shift;

             $signer->add_signature(
                     new Mail::DKIM::Signature(
                         Algorithm => $signer->algorithm,
                         Method => $signer->method,
                         Headers => $signer->headers,
                         Domain => $signer->domain,
                         Selector => $signer->selector,
                     ));
             return;
         }

       Again, if you do not want any signatures, return zero or undef. If you use add_signature()
       to create a signature, the default signature will not be created, even if you return
       nonzero.

AUTHOR

       Jason Long, <jlong@messiah.edu>

COPYRIGHT AND LICENSE

       Copyright (C) 2006-2007 by Messiah College

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of
       Perl 5 you may have available.