Re: Enough DMARC whinging

[Miles Fidelman <[e-mail]>]

Dave Crocker wrote:
> On 5/1/2014 2:51 PM, Mark Andrews wrote:
>> In message <[e-mail]>, Miles Fidelman writes:
>>> Dave Crocker wrote:
>>>>>      5. The IESG has concluded that this document extends an IETF protocol
>>>>>         in a way that requires IETF review and should therefore not be
>>>>>         published without IETF review and IESG approval.
>>>> Since DMARC does not extend any existing IETF protocol, how is that
>>>> reference useful here?
>>> Sure looks to me like DMARC extends both SMTP and DNS.
>> And DKIM.
>
> No, No, and No.
>
> Don't confuse 'use' with 'extend'.
>
> TCP "uses" IP.  It does not "extend" it.  That's what architectural
> layering is about.  Functions above a layer do not extend the lower
> layer; they use it.
>
> DMARC /uses/ DKIM (and SPF).  It does not alter (extend) either of them.
>
> As for any claim that DMARC 'extends' SMTP or DNS, it's difficult to
> imagine the technical logic behind such an assertion.

1. DMARC essentially species a change to the behavior of mail 
reception.  It sure looks to me like an extension to the state machine 
model for mail processing, at the SMTP level.  Arguably, the same can be 
said for what forwarders (including mailing list processors) do.

2. As to DNS: There's a long standing argument about the use of TXT 
records for purposes beyond holding "descriptive data."  Last time I 
looked (just now) there has been nothing since RFC1035, which states 
"TXT RRs are used to hold descriptive text" and RF1464, about storing 
arbitrary string attributes, and remains experimental. DKIM, SPF, and 
DMARC both define and use TXT RRs in ways that go beyond their defined 
scope.
>
> d/
>
> ps.  The original note was from Jim Fenton and it was him I was asking
> to explain his reference.  He seemed to be making a point and I was
> asking him to provide it explicitly.
>
Yes.  I'm agreeing with Jim, and providing some backup to his point.

Miles Fidelman

-- 
In theory, there is no difference between theory and practice.
In practice, there is.   .... Yogi Berra