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

From: Adam Roach <[email-masked]>
Date: Tue, 10 Oct 2017 18:10:43 -0700

Adam Roach has entered the following ballot position for
draft-ietf-lamps-rfc5280-i18n-update-03: Discuss

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DISCUSS:
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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.

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COMMENT:
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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.

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?

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

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From: Russ Housley <[email-masked]>
Date: Wed, 11 Oct 2017 14:22:07 -0400

> On Oct 10, 2017, at 9:10 PM, Adam Roach <[email-masked]> wrote:
> 

Right.  I'll correct that text.

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

> stated by simply increasing such buffers by a single byte. Surely that's not

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.

> you might want to remove it)

It is more of an implementation consideration.

Russ

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 12 Oct 2017 07:08:47 +0100

> Right.  I'll correct that text.

Good catch. I think just deleting local-part from the list should do.