Mail::DKIM::DkSignature(3)

NAME
Mail::DKIM::DkSignature - represents a DomainKeys-Signature header

VERSION
version 1.20230212

CONSTRUCTORS

  new()
Create a new DomainKey signature from parameters

  my $signature = Mail::DKIM::DkSignature->new(
                      [ Algorithm => 'rsa-sha1', ]
                      [ Signature => $base64, ]
                      [ Method => 'simple', ]
                      [ Domain => 'example.org', ]
                      [ Headers => 'from:subject:date:message-id', ]
                      [ Query => 'dns', ]
                      [ Selector => 'alpha', ]
                      [ Key => $private_key, ]
                  );

  parse()
Create a new signature from a DomainKey-Signature header

  my $sig = Mail::DKIM::DkSignature->parse(
                  'DomainKey-Signature: a=rsa-sha1; b=yluiJ7+0=; c=nofws'
            );

Constructs a signature by parsing the provided DomainKey-Signature header content. You do not have to include the header name (i.e. "DomainKey-Signature:") but it is recommended, so the header name can be preserved and returned the same way in "as_string()".

Note: The input to this constructor is in the same format as the output of the as_string method.

METHODS

  as_string()
Convert the signature header as a string.

  print $signature->as_string . "\n";

outputs

  DomainKey-Signature: a=rsa-sha1; b=yluiJ7+0=; c=nofws

As shown in the example, the as_string method can be used to generate the DomainKey-Signature that gets prepended to a signed message.

  algorithm()
Get or set the algorithm (a=) field

The algorithm used to generate the signature. Defaults to "rsa-sha1", an RSA-signed SHA-1 digest.

  canonicalization()
Get or set the canonicalization (c=) field.

  $signature->canonicalization('nofws');
  $signature->canonicalization('simple');

  $method = $signature->canonicalization;

Message canonicalization (default is "simple"). This informs the verifier of the type of canonicalization used to prepare the message for signing.

  domain()
Get or set the domain (d=) field.

  my $d = $signature->domain;          # gets the domain value
  $signature->domain('example.org');   # sets the domain value

The domain of the signing entity, as specified in the signature. This is the domain that will be queried for the public key.

  headerlist()
Get or set the signed header fields (h=) field.

  $signature->headerlist('a:b:c');

  my $headerlist = $signature->headerlist;

  my @headers = $signature->headerlist;

Signed header fields. A colon-separated list of header field names that identify the header fields presented to the signing algorithm.

In scalar context, the list of header field names will be returned as a single string, with the names joined together with colons. In list context, the header field names will be returned as a list.

  identity()
Get the signing identity.

  my $i = $signature->identity;

In DomainKey signatures, the signing identity is the first address found in the Sender header or the From header. This field is populated by the Verifier when processing a DomainKey signature.

  identity_source()
Determine which header had the identity.

  my $source = $signature->identity_source;

If the message is being verified, this method will tell you which of the message headers was used to determine the signature identity. Possible values are "header.sender" and "header.from".

  protocol()
Get or set the query methods (q=) field.

A colon-separated list of query methods used to retrieve the public key (default is "dns").

  selector()
Get or set the selector (s=) field.

The selector subdivides the namespace for the "d=" (domain) tag.

  signature()
Get or set the signature data (b=) field.

The signature data. Whitespace is automatically stripped from the returned value.

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.