Mail::DKIM::DkPolicy (3pm)

DomainKeys sender signing policies are described in \s-1RFC4870\s0(historical). It is a record published in the message sender's (i.e. the person who transmitted the message) \s-1DNS\s0 that describes how they sign messages.

\fIfetch()\fP - fetch a sender signing policy from \s-1DNS\s0

  my $policy = Mail::DKIM::DkPolicy->fetch(
                   Protocol => "dns",
                   Sender => '[email protected]',
               );

The following named arguments are accepted:

Protocol

always specify \*(L"dns\*(R"

Author

the \*(L"author\*(R" of the message for which policy is being checked. This is the first email address in the \*(L"From\*(R" header. According to \s-1RFC\s0 2822, section 3.6.2, the \*(L"From\*(R" header lists who is responsible for writing the message.

Sender

the \*(L"sender\*(R" of the message for which policy is being checked. This is the first email address in the \*(L"Sender\*(R" header, or if there is not a \*(L"Sender\*(R" header, the \*(L"From\*(R" header. According to \s-1RFC\s0 2822, section 3.6.2, the \*(L"Sender\*(R" header lists who is responsible for transmitting the message.

Depending on what type of policy is being checked, both the Sender and Author fields may need to be specified.

If a \s-1DNS\s0 error or timeout occurs, an exception is thrown.

Otherwise, a policy object of some sort will be returned. If no policy is actually published, then the \*(L"default policy\*(R" will be returned. To check when this happens, use

my $is_default = $policy->is_implied_default_policy;

\fInew()\fP - construct a default policy object

my $policy = Mail::DKIM::DkPolicy->new;

\fIparse()\fP - gets a policy object by parsing a string

my $policy = Mail::DKIM::DkPolicy->parse( String => "o=~; t=y" );

\fIapply()\fP - apply the policy to the results of a \s-1DKIM\s0 verifier

my $result = $policy->apply($dkim_verifier);

The caller must provide an instance of Mail::DKIM::Verifier, one which has already been fed the message being verified.

Possible results are:

accept

The message is approved by the sender signing policy.

reject

The message is rejected by the sender signing policy.

neutral

The message is neither approved nor rejected by the sender signing policy. It can be considered suspicious.

\fIflags()\fP - get or set the flags (t=) tag

A vertical-bar separated list of flags.

\fIis_implied_default_policy()\fP - is this policy implied?

my $is_implied = $policy->is_implied_default_policy;

If you fetch the policy for a particular domain, but that domain does not have a policy published, then the \*(L"default policy\*(R" is in effect. Use this method to detect when that happens.

\fIlocation()\fP - where the policy was fetched from

DomainKeys policies only have per-domain policies, so this will be the domain where the policy was published.

If nothing is published for the domain, and the default policy was returned instead, the location will be \*(C`undef\*(C'.

\fInote()\fP - get or set the human readable notes (n=) tag

Human readable notes regarding the record. Undef if no notes specified.

\fIpolicy()\fP - get or set the outbound signing policy (o=) tag

my $sp = $policy->policy;

Outbound signing policy for the entity. Possible values are: The default. The domain may sign some (but not all) email. The domain signs all email.

\fItesting()\fP - checks the testing flag

my $testing = $policy->testing;

If nonzero, the testing flag is set on the signing policy, and the verify should not consider a message suspicious based on this policy.

Jason Long, <[email protected]>

Copyright (C) 2006-2009 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.