NAME

       Mail::DKIM::ARC::MessageSignature - Subclass of Mail::DKIM::Signature which represents a
       ARC-Message-Signature header

VERSION

       version 1.20230212

CONSTRUCTORS

   new() - create a new signature from parameters
         my $signature = Mail::DKIM::ARC::MessageSignature->new(
                             [ Algorithm => 'rsa-sha256', ]
                             [ Signature => $base64, ]
                             [ Method => 'relaxed', ]
                             [ Domain => 'example.org', ]
                             [ Instance => 1, ]
                             [ Headers => 'from:subject:date:message-id', ]
                             [ Query => 'dns', ]
                             [ Selector => 'alpha', ]
                             [ Timestamp => time(), ]
                             [ Expiration => time() + 86400, ]
                         );

       The only differences between this module and Mail::DKIM::Signature are the header name,
       and that 'instance' is an integer rather than a base64 encoded value.

   instance() - get or set the signing instance (i=) field
         my $i = $signature->instance;

       Instances must be integers less than 1024 according to the spec.

       NOTE: the i= field is "Identity" in DKIM and is a base64 value, but in ARC it is
       "Instance" and an integer.  The parsing routine does not check that the i= value is a
       number.

SEE ALSO

       Mail::DKIM::Signature for DKIM-Signature headers

AUTHORS

       •   Jason Long <jason@long.name>

       •   Marc Bradshaw <marc@marcbradshaw.net>

       •   Bron Gondwana <brong@fastmailteam.com> (ARC)

THANKS

       Work on ensuring that this module passes the ARC test suite was generously sponsored by
       Valimail (https://www.valimail.com/)

COPYRIGHT AND LICENSE

       •   Copyright (C) 2013 by Messiah College

       •   Copyright (C) 2010 by Jason Long

       •   Copyright (C) 2017 by Standcore LLC

       •   Copyright (C) 2020 by FastMail Pty Ltd

       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.