Re: [dmarc-ietf] ARC questions

Dave Crocker <dcrocker@gmail.com> Mon, 23 November 2020 19:53 UTC

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To: Brandon Long <blong=40google.com@dmarc.ietf.org>
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From: Dave Crocker <dcrocker@gmail.com>
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Date: Mon, 23 Nov 2020 11:53:12 -0800
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Subject: Re: [dmarc-ietf] ARC questions
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On 11/23/2020 11:42 AM, Brandon Long wrote:
> 
> 
> On Mon, Nov 23, 2020 at 11:34 AM Dave Crocker <dhc@dcrocker.net 
> <mailto:dhc@dcrocker.net>> wrote:
> 
>     On 11/23/2020 11:29 AM, Brandon Long wrote:
>      > The DKIM-Signature is an "ownership" thing, it's a message
>     originator
>      > that is saying
>      > "associate this message to me".
> 
>     That is not DKIM's semantics:
> 
>          "DomainKeys Identified Mail (DKIM) permits a person, role, or
>          organization to claim some responsibility for a message by
>          associating a domain name"
> 
>     This says nothing about whether the organization has anything to do
>     with
>     origination.
> 
>     There is nothing to prohibit or preclude handling agents other than the
>     originator from signing.
> 
> 
> Yes, of course, a handling agent can do it, but there are plenty of reasons
> why they shouldn't.

Please enumerate and explain.  If it's that dangerous, we should 
document it, especially I don't recall that constraint being in any of 
the design or standardization discussions.



>      > Intermediaries don't want to take ownership of the message in that
>      > sense, though there
>      > are some mailing lists that do.
> 
>     Signing with DKIM does not take 'ownership'.
> 
> 
> Yes, responsibility is the proper word.  My point survives the word change.

I disagree.


> DKIM says the domain takes responsibility for the message, while ARC says
> the domain takes responsibility for evaluating the status of the message 
> when
> they received and forwarded it.

This implies that the word 'some' is irrelevant.  It isn't.  And it was 
included intentionally.


d/
-- 
Dave Crocker
dcrocker@gmail.com
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