Subject: [ietf-dkim] Issue 1543: remove [FWS]

From: Stephen Farrell <[email-masked]>
Date: Thu, 03 Jul 2008 13:57:29 +0100

Issue descritption: https://rt.psg.com/Ticket/Display.html?id=1543

ssp-04 still includes the FWS, I didn't see a clear consensus on the
list either way (or else I missed some messages;-)

If we really need a strawpoll/consensus check on this please say so
and I'll start one.

Otherwise, I'll assume its ok to stick with FWS and ask Eliot to
close this one on July 11.

S.

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From: Jim Fenton <[email-masked]>
Date: Thu, 10 Jul 2008 08:39:43 -0700

> close this one on July 11.
To clarify what happened, I had changed [FWS] to *WSP in the ssp-02 
ABNF, in response to this issue.  It stayed that way in -03.  In 
response to Eric's comment below (forwarded with permission), John 
changed it to *FWS in -04.  I think we're agreed that [FWS] is more 
correct than *FWS, but there's probably still some difference of opinion 
on [FWS] vs. *WSP.  Here (I think) are the arguments on both sides:

- Favoring *WSP:  It doesn't make sense to require a leading whitespace 
character following CR/LF in a DNS record, since the leading whitespace 
applies to identifying continuation lines in RFC 2822 header fields.

- Favoring [FWS]:  This is the ABNF used in RFC 4871, and it doesn't 
make sense to introduce a different parsing requirement for ADSP.

Thoughts?

-Jim

-------- Original Message --------
Subject: 	Re: [SA]SP ABNF for white space
Date: 	Sun, 24 Feb 2008 11:38:45 -0800
From: 	Eric Allman <[email-masked]>
To: 	Jim Fenton <[email-masked]>
CC: 	John Levine <[email-masked]>
References: 	<[email-masked]> 
<[email-masked]>

Jim,

I'm willing to discuss the point of what we should have done in 4871, 
but that's not the topic right now.  The fact is that 4871 already 
permits folding in TXT records and ssp-02 does not.  Implementations 
really should be able to use the same parser for these two cases, 
since they are identical.  Making them different is begging for 
implementation inconsistency.

eric

--On February 24, 2008 10:16:16 AM -0800 Jim Fenton 
<[email-masked]> wrote:

> Eric,
>
> Yes, I changed this in response to an issue raised by Frank
> Ellermann.  I didn't see how the mail-header convention of
> continuing lines by putting whitespace at the beginning of the
> continuation line made sense in a DNS TXT record.  There was some
> discussion about leaving out whitespace in the ABNF altogether, but
> I thought it helped readability to put in optional whitespace,
> *WSP, in order to make sure implementations reading the record
> could handle whitespace because somebody's going to put it in
> anyway.
>
> Sorry if this is a surprise; this happened during your downtime.  I
> don't think there are any other surprises like this though.
>
> -Jim
>
> Eric Allman wrote:
>> Jim,
>>
>> I just noticed that the ABNF changed between ssp-01 and ssp-02 to
>> use  *WSP instead of [FWS].  These are semantically different, and
>> 4871  uses [FWS].  In particular, the definition of tag-list in
>> 4871 uses  [FWS], which means that there is a conflict in ssp-02,
>> which says that  the tag-list is the same syntax as in 4871 but
>> then defines the  individual tags using a different syntax.
>>
>> Sorry if this isn't clear.  I did want to check with you before I
>> posted something to the list in case I'm missing something obvious.
>>
>> eric
>>
>

---

From: "Frank Ellermann" <[email-masked]>
Date: Thu, 10 Jul 2008 19:20:31 +0200

> Thoughts?

Close the ticket as soon as *FWS is replaced by either
*WSP or [FWS].  Maybe add text in the direction of...

| [FWS] is expected to be replaced by *SP or similar
| in a future update of [RFC4871].

...for the [FWS] variant.  The TAB in *WSP is also not
more state of the art (as documented in RFC 5198), so
maybe 4871bis will pick *SP after/if FWS failed in the
implementation and interop tests for a draft standard.

 Frank

---

From: Jim Fenton <[email-masked]>
Date: Thu, 10 Jul 2008 12:10:18 -0700

Frank Ellermann wrote:
> *WSP or [FWS].

Well, OK, but I'll point out that when the ticket was opened, the text 
said [FWS].

-Jim

---

From: "Frank Ellermann" <[email-masked]>
Date: Thu, 10 Jul 2008 23:13:14 +0200

> Well, OK, but I'll point out that when the ticket was
> opened, the text said [FWS].

Yes, and the submitter of this ticket found that there
are far worse things than [FWS] when he saw the *FWS ;-)

Apparently folks agree that [FWS] in DNS is nonsense, but
in line with RFC 4871:  Ordre, contreordre, désordre.

 Frank