Subject: [dmarc-ietf] Consensus Sought - Ticket #53 (Remove reporting message size chunking) - With Interim Notes

From: Todd Herr <[email-masked]>
Date: Fri, 28 May 2021 11:46:20 -0400

Greetings.

Consensus on Ticket #53 <https://trac.ietf.org/trac/dmarc/ticket/53>
(Remove reporting message size chunking) was reached during the May 27
DMARC Interim to remove the feature and update the IANA registry and ABNF
grammar as necessary.

I seek consensus from the working group at large on this ticket, and
request that a decision be made by Friday, June 11. Discussions about this
issue should be contained in this thread.

Thank you.

-- 

*Todd Herr* | Sr. Technical Program Manager
*e:* [email-masked]
*m:* 703.220.4153

This email and all data transmitted with it contains confidential and/or
proprietary information intended solely for the use of individual(s)
authorized to receive it. If you are not an intended and authorized
recipient you are hereby notified of any use, disclosure, copying or
distribution of the information included in this transmission is prohibited
and may be unlawful. Please immediately notify the sender by replying to
this email and then delete it from your system.

---

From: Alessandro Vesely <[email-masked]>
Date: Fri, 28 May 2021 19:25:10 +0200

On Fri 28/May/2021 17:46:20 +0200 Todd Herr wrote:
> 
> Consensus on Ticket #53 <https://trac.ietf.org/trac/dmarc/ticket/53> (Remove 
> reporting message size chunking) was reached during the May 27 DMARC Interim to 
> remove the feature and update the IANA registry and ABNF grammar as necessary.

Agreed.  However, the grammar should be retained in order to not invalidate 
existing records.  Any !10m tail should just be ignored.

Best
Ale
--

---

From: "John Levine" <[email-masked]>
Date: 28 May 2021 14:01:22 -0400

>existing records.  Any !10m tail should just be ignored.

What I heard at the interim was that not only does nobody implement size limits,
some large receivers don't recognize the !nn suffix and the reports fail.  Take
it out so the spec agrees with reality.

R's,
John

---

From: Dotzero <[email-masked]>
Date: Fri, 28 May 2021 14:31:40 -0400

On Fri, May 28, 2021 at 2:01 PM John Levine <[email-masked]> wrote:

> (Remove

+1 to what John wrote.

Michael Hammer

---

From: Steven M Jones <[email-masked]>
Date: Fri, 28 May 2021 17:30:47 -0700

On 5/28/21 08:46, Todd Herr wrote:
> DMARC Interim to remove the feature and update the IANA registry and
> ABNF grammar as necessary.

I support the removal, unless a report generator speaks up by June 11th
saying they support the feature.

---

From: Alessandro Vesely <[email-masked]>
Date: Sat, 29 May 2021 11:29:23 +0200

On Sat 29/May/2021 02:30:47 +0200 Steven M Jones wrote:
>> reporting message size chunking) was reached during the May 27 DMARC Interim 
>> to remove the feature and update the IANA registry and ABNF grammar as necessary.
> 
> I support the removal, unless a report generator speaks up by June 11th saying 
> they support the feature.

If, by supporting, you mean coding, then I, for one, support it.  What I do is 
to recognize the ! suffix and abort sending if that is exceeded.  I heard that 
Google instead do a real chunking; that is, they'd send a truncated report 
followed by the remaining chunks, all within the limits.

However, despite my coding, that feature was never triggered.  And I never 
heard about the top aggregate report sizes at large provider's.

Best
Ale
--

---

From: Barry Leiba <[email-masked]>
Date: Sun, 30 May 2021 19:41:08 -0400

Yes,  but you’re speaking as a report CONSUMER.  Steve said “report
generator”, and the point is that there is no evidence that anyone
generates this.  Yes?

Barry

On Sat, May 29, 2021 at 5:29 AM Alessandro Vesely <[email-masked]> wrote:

> _______________________________________________
> dmarc mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/dmarc
>

---

From: Alessandro Vesely <[email-masked]>
Date: Mon, 31 May 2021 10:58:01 +0200

On Mon 31/May/2021 01:41:08 +0200 Barry Leiba wrote:
> generator”, and the point is that there is no evidence that anyone generates
> this.  Yes?

No, I meant recognizing the suffix and aborting as producer actions.  That is 
roughly documented by saying: "If the size limit is exceeded, the child is 
killed with SIGTERM."
https://www.tana.it/sw/zdkimfilter/zaggregate.html

Concoction about Google's behavior originated from Brandon's sentence: "We 
already generate multiple reports to address because of size constraints."
http://lists.dmarc.org/pipermail/dmarc-discuss/2020-January/004326.html

Best
Ale
-- 

> [...]
>> What I do is to recognize the ! suffix and abort sending if that is
>> exceeded.  I heard that Google instead do a real chunking[...]

---

From: Steven M Jones <[email-masked]>
Date: Mon, 31 May 2021 15:49:45 -0700

I'm not philosophically or religiously opposed to removing the size
limit but I would like to have some data, or at least informed feedback,
to justify the decision.

This feature was not in the original December 2011 specification, but
was added in the March 2012 revision (both were pre-IETF). I'm betting
that was done because of first-hand operational issues, though of course
things have changed in ~10 years and it may no longer be necessary.

I appreciate Ale's anecdote that his size-limit code has never been
triggered, that kind of information is useful. I think the larger report
generators are the best place available to get this information, and I
will try to chase down people who can provide it this week.

I think we can get the input needed to resolve this by Todd's requested
deadline, and be able to show we did the due diligence to back up the
decision.

Thanks,
--S.