Hi
I would like to know your opinion on the options currently available to
the system administrator. If it is trying to define a policy that allows
recipients to authenticate emails, its options are, in my opinion, limited.
- The issue of SPF and cloud systems mentioned, or including over
networks with mask /8 or /16 is extremely inappropriate
- It is not possible to set up the enforcement of DKIM signatures
because DomainKey and its policies are not related to DKIM and there is
no similar technology for DKIM (ADSP is not used)
- If I am the administrator of hundreds or thousands of domains, it is
in my interest to provide the recipient with information about the
sender's authentication options. For example, all emails use DKIM, all
emails use ARC, all emails use SPF ... and if not, you can discard them.
But I do not have this option with DMARC.
I understand that this is in the middle of what DMARC2 is supposed to
address. But could there be a possibility for the DMARC2 record
administrator to define a policy for domains and provide relevant
information for recipients? It is the recipient's decision whether to do
this verification, but it is also the sender's decision to offer this
information. Unfortunately, at this point, either the signature is
valid, or wrong, or it is not. If it is not possible to accept the
e-mail, but the recipient does not have the option of verifying whether
the sender's domain enforces this signature. It is similar with SPF. And
DMARC2 seems to me to be a good place for these definitions. But I would
like to avoid of forced removal of SPF, please let it for administrator
decision.
Regards
Jan
Dne 16. 6. 2023 v 13:28 Sebastiaan de Vos napsal(a):
The need for separate DKIM failure codes to be able to separate
between in-transit changes and public key errors is more than just
valid and I don't consider SPF worthless in general, but I just find
it disturbing how the obviously misplaced confidence in SPF currently
weakens the whole DMARC standard.
Is it not in our best interest to encourage and motivate in particular
the less sophisticated senders to use the higher confidence mechanisms?
On 16.06.23 13:02, Douglas Foster wrote:
RFC 7489 takes 8 different authentication mechanisms and lumps them
into a single PASS result:
DKIM or SPF, each with up to four types of alignment: same domain,
parent->child, child->parent, and sibling->sibling
These eight mechanisms all provide some level of confidence that the
message is not impersonated, but they do not provide an equal level
of confidence.
Unsophisticated senders have little incentive to use the higher
confidence mechanisms because any PASS result is still PASS. The
solution is not to pretend that SPF is worthless, because that is an
overstatement. The solution is to talk about the differences in
confidence provided by the different authentication methods, and note
that evaluators have reason to distrust some of them. That distrust
could cause a weakly authenticated message to be distrusted by some
evaluators.
Similarly, needs multiple types of FAIL. Since the data indicates
that missing (or invalid) public keys are a significant portion of
all failures, it needs a separate failure code from "normal" failures
which suggest in-transit changes. The DKIM group needs to define the
result code but this group would need to integrate it into our
aggregate reports.
--
-- --- ----- -
Jan Dušátko
Tracker number: +420 602 427 840
e-mail: j...@dusatko.org
GPG Signature: https://keys.dusatko.org/E535B585.asc
GPG Encrypt: https://keys.dusatko.org/B76A1587.asc
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