Distributed configuration of "private" IDNA (Re: IDNA and getnameinfo() and getaddrinfo())

[Andrew Sullivan]

On Thu, Jun 17, 2010 at 11:11:55AM -0500, Nicolas Williams wrote:
> 
> See "First: to note that...".  That is: I don't think DNS, much less
> _application_ implementors can be expected to support private DNS clouds
> with non-standard IDN rules.  It's just too big a PITA.

Hold on, there.  The DNS allows _octets_ in domain name labels.  That
is, you can put "*&^_+é" to you heart's content in a DNS label, and it
all oughta be legal.  STD13 is perfectly clear on that:

    Each node has a label, which is zero to 63 octets in length.
    Brother nodes may not have the same label, although the same label
    can be used for nodes which are not brothers.  One label is
    reserved, and that is the null (i.e., zero length) label used for
    the root.

    […]

    The rationale for this [different-context] choice is that we may
    someday need to add full binary domain names for new services;
    existing services would not be changed.

The actual facts of the matter, and those facts' interaction with
other conventions, restrictions, and the myriad deployed stuff, is
rather different, which is how we got to IDNA2008.  But claiming that
"DNS can't be expected to support private DNS clouds with non-standard
IDN rules" misses the boat by almost 25 years.  It always did.

A

-- 
Andrew Sullivan
ajs at shinkuro.com
Shinkuro, Inc.