Re: [lamps] Adam Roach's Discuss on draft-ietf-lamps-rfc5280-i18n-update-03: (with DISCUSS and COMMENT)

[Russ Housley <[e-mail]>]

> On Oct 10, 2017, at 9:10 PM, Adam Roach <[e-mail]> wrote:
> 
> Adam Roach has entered the following ballot position for
> draft-ietf-lamps-rfc5280-i18n-update-03: Discuss
> 
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> 
> Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
> for more information about IESG DISCUSS and COMMENT positions.
> 
> 
> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-lamps-rfc5280-i18n-update/
> 
> 
> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> The final paragraph in Section 2.4 reads:
> 
>   Implementations should convert the local-part and the host-part of
>   internationalized email addresses placed in these extensions to
>   Unicode before display.
> 
> The mention of converting "local-part" to "Unicode" has a very strong
> implication that the local-part of internationalized email addresses can be
> (should be?) ACE-encoded (or otherwise converted to some non-Unicode encoding).
> Unless my understanding of internationalized email addresses is wildly wrong
> (and that may be the case), this isn't how they work: the local-part *is* in
> Unicode, and so conversion to Unicode doesn't make sense.
> 
> This seems highly likely to lead developers down the path of ACE-encoding the
> local-part component of email addresses, which would cause incompatibilities.

Right.  I'll correct that text.

> 
> 
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> The document has several instances of (lower-case) "should" where talking about
> implementation behavior. These look like they should be normative to me -- if
> that's the intention, please make them uppercase. If not, please update to RFC
> 8174 boilerplate.

Okay.  I'll double check each use of "should" in the document.


> The document contains the following normative requirement:
> 
>   Note:  Implementations MUST allow for increased space requirements
>   for IDNs.
> 
> It's hard to determine what an implementation needs to do in order to satisfy
> this normative requirement. Presumably, "increased" is relative to previous
> buffer allocations for domain names? Also, the statement can be satisfied as
> stated by simply increasing such buffers by a single byte. Surely that's not
> what's intended, is it?

The real assistance comes in the next sentence:

   An IDN ACE label will begin with the four additional
   characters "xn--" and may require as many as five ASCII characters to
   specify a single international character.

> (Aside: I find the use of "Note:" preceding normative text to be confusing, so
> you might want to remove it)

It is more of an implementation consideration.

Russ