Mail::DKIM::AuthorDomaUserlContributed Perl DMail::DKIM::AuthorDomainPolicy(3)
NAME
Mail::DKIM::AuthorDomainPolicy - represents an Author Domain Signing
Practices (ADSP) record
VERSION
version 1.20200907
DESCRIPTION
The Author Domain Signing Policies (ADSP) record can be published by
any domain to help a receiver know what to do when it encounters an
unsigned message claiming to originate from that domain.
The record is published as a DNS TXT record at _adsp._domainkey.DOMAIN
where DOMAIN is the domain of the message's "From" address.
More details about this record can be found by reading the
specification itself at <http://tools.ietf.org/html/rfc5617>.
CONSTRUCTORS
fetch()
Lookup an ADSP record in DNS.
my $policy = Mail::DKIM::AuthorDomainPolicy->fetch(
Protocol => 'dns',
Author => 'jsmith AT example.org',
);
If the ADSP record is found and appears to be valid, an object
containing that record's information will be constructed and returned.
If the ADSP record is blank or simply does not exist, an object
representing the default policy will be returned instead. (See also
"is_implied_default_policy()".) If a DNS error occurs (e.g. SERVFAIL
or time-out), this method will "die".
new()
Construct a default policy object.
my $policy = Mail::DKIM::AuthorDomainPolicy->new;
parse()
Construct an ADSP record from a string.
my $policy = Mail::DKIM::AuthorDomainPolicy->parse(
String => 'dkim=all',
Domain => 'aaa.example',
);
METHODS
apply()
Apply the policy to the results of a DKIM 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. It can be
considered very suspicious.
neutral
The message is neither approved nor rejected by the sender signing
policy. It can be considered somewhat suspicious.
Note: in the future, these values may become:
none - no ADSP record is published
pass - a passing signature is present
fail - ADSP record is "all" and no passing signature is found
discard - ADSP record is "discardable" and no passing signature is
found
nxdomain - the DNS domain does not exist
temperror - transient error occurred
permerror - non-transient error occurred
is_implied_default_policy()
Tells whether 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 "default policy" is in effect.
Use this method to detect when that happens.
location()
Tells where the policy was fetched from.
If the policy is domain-wide, this will be domain where the policy was
published.
If the policy is user-specific, TBD.
If nothing is published for the domain, and the default policy was
returned instead, the location will be "undef".
policy()
Get or set the outbound signing policy (dkim=) tag.
my $sp = $policy->policy;
Outbound signing policy for the entity. Possible values are:
"unknown"
The default. The entity may sign some or all email.
"all"
All mail from the domain is expected to be signed, using a valid
Author signature, but the author does not suggest discarding mail
without a valid signature.
"discardable"
All mail from the domain is expected to be signed, using a valid
Author signature, and the author is so confident that non-signed
mail claiming to be from this domain can be automatically discarded
by the recipient's mail server.
"NXDOMAIN"
The domain is out of scope, i.e., the domain does not exist in the
DNS.
signall()
True if policy is "all".
signall_discardable()
True if policy is "strict".
BUGS
o Section 4.3 of the specification says to perform a query on the
domain itself just to see if it exists. This class is not currently
doing that, i.e. it might report NXDOMAIN because
_adsp._domainkey.example.org is nonexistent, but it should not be
treated the same as example.org being nonexistent.
AUTHORS
o Jason Long <jason AT long.name>
o Marc Bradshaw <marc AT marcbradshaw.net>
o Bron Gondwana <brong AT 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
o Copyright (C) 2013 by Messiah College
o Copyright (C) 2010 by Jason Long
o Copyright (C) 2017 by Standcore LLC
o 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.
perl v5.26.3 2020-09-07 Mail::DKIM::AuthorDomainPolicy(3)