Re: [idn] length restrictions on IDN label

["James Seng" <jseng@pobox.org.sg>]

> Your argument stands only in DNS on-the-wire context. IN all other
> protocol/display
>  contexts, utf8 labels are legitimate domain labels. That is why zone
> admins may input
> their labels in utf8 into their zone files and end users recoginze them
> as  domain names.

utf8 labels have no meaning as domain name labels, as currently defined in
RFC 1034/1035, whether on wire or otherwise. anything above 127 is a
no-man-zone-use-it-at-your-own-risk.

If you mean IDN labels encoded in UTF-8, then the restriction is fairly
simply, one already explained to you multiple times, octet(ToASCII(X))<=63.

> Moreover,
> I didn't limit my question into  DNS and its protocols (just 'protocol',
> DNS is not the  'all')
> Rather, that may span into all application protocols that use domain
names,
> like future ESMTP.

Then it is worst then you think. This working group is definately not going
to be able to address all the concerns of all application protocols that
uses domain names, much less a future work in ESMTP. That work should be
address in other specific applications protocol and DEFINATELY not in this
working group.

I still hope to conclude this working group within the next few months and
get on with my life, dealing with other IDN related issues.

> There will be many application protocols (IETF's or home-made) that
> may exchange utf8-form labels as protocols elements (not for human eyes)
> according to IDNA section 6.1-3. IDNA draft granted such use of utf8
> labels as legitimate one.

Then shouldn't that application protocol be updated?

> Length restriction should be clarified before  IDN  deployments.
> Currently valid IDN label should not be invalidated in the future due to
> today's misspecifications.

Yes, it should be clarify if there is any confusion.

But there is no confusion as far as I know. The length restriction is quite
clear, octet(ToASCII(X))<=63. Or are you still confused?

> To avoid  buffer overflow errors and security breaches, label length
issues
> are practically important to implementors who want to estimate enough
> buffer
> spaces for IDN labels.

Since when implementation issue is part of the working group charter?

Please stop....Some might be scared by your FUD.

-James Seng