Re: Last Call: <draft-ietf-lamps-eai-addresses-05.txt> (Internationalized Email Addresses in X.509 certificates) to Proposed Standard

"Patrik Fältström " <paf@frobbit.se> Tue, 24 January 2017 04:54 UTC

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From: Patrik Fältström <paf@frobbit.se>
To: John Levine <johnl@taugh.com>
Subject: Re: Last Call: <draft-ietf-lamps-eai-addresses-05.txt> (Internationalized Email Addresses in X.509 certificates) to Proposed Standard
Date: Tue, 24 Jan 2017 05:54:25 +0100
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On 24 Jan 2017, at 3:01, John Levine wrote:

> In article <14A8995E-D7BF-4994-98F8-875CCED02085@frobbit.se> you write:
>>> I think this needs to be discussed a bit more in the LAMPS WG, but you have a good point here.
>>
>> I would extend to 'starting in "XX--" where X can be any ascii character" because who knows whether we need a
>> completely different prefix one day.
>
> I hope you mean X can be any ascii letter or digit.  After all, Ctrl/C is an ASCII character.

Yes, of course.

>> Or you should explicitly note that ascii-only mailboxes do imply the literal value and those strings MUST NOT
>> be interpreted as A-Labels.
>
> Urrgh.  As far as I know, this is an entirely valid ASCII address:
>
>   fred@xn--exmple-qta.com
>
> That domain name happens to be the A-label for exámple.com but so what?

Sure, but my point was that this spec must make up its mind here. Should labels be allowed which being with XX-- be allowed or not, and if they are (instead of just ignored) should they be interpreted as their literal values or as A-Labels?

What I see is that one do *NOT* want to allow labels starting with XX-- (as one must use U-Lables) but I see between the lines that the reasoning behind that is that there might be some backward compatibility to cases where already deployed labels exists in the wild that start with XX--.

This should be spelled out explicitly in the draft so that people really understand what the thinking in, and not hidden in some (for non-english speaking people) complicated english.

   paf