[Mimedefang] What about DKIM

[David F. Skoll]

On Thu, 9 May 2013 12:14:40 -0600
Philip Prindeville <philipp_subx at redfish-solutions.com> wrote:

> And DKIM support for verification is in SpamAssassin, but I'm not
> seeing any support for signing in MimeDefang.

It is very easy to add.  Use the Mail::DKIM::Signer and Mail::DKIM::TextWrap
modules from CPAN.  This is in our filter and we call it to sign a message
from filter_end:

sub dkim_sign
{
        my $dkim = Mail::DKIM::Signer->new(
                Algorithm => "rsa-sha1",
                Method => "relaxed",
                Domain => "roaringpenguin.com",
                Selector => "main",
                KeyFile => "/etc/ssl/private/roaringpenguin.com.dkim.2048.key");
        if (open(TOSIGN, "<INPUTMSG")) {
                while(<TOSIGN>) {
                        # remove local line terminators
                        chomp;
                        s/\015$//;

                        # use SMTP line terminators
                        $dkim->PRINT("$_\015\012");
                }
                close(TOSIGN);
                $dkim->CLOSE();
                my $signature = $dkim->signature()->as_string();
                $signature =~ s/^DKIM-Signature:\s+//i;
                action_add_header('DKIM-Signature', $signature);
        }
}

Regards,

David.