Re: [idn] Debunking the ACE myth

["Adam M. Costello" <amc@cs.berkeley.edu>]

Dan Oscarsson <Dan.Oscarsson@trab.se> wrote:

> If we allow a response to have non-namprepped names (ACE or UTF-8),
> only a IDN aware client can use that name to send new queries because
> only those will do nameprep before sending the query. So all other
> clients may fail when using a name returned from DNS.

Non-nameprep'd ACE is pointless, so forget about that.  You're right
that it would be bad to return non-nameprep'd UTF-8 to IDN-unaware
clients, but I think it would be bad to return any non-ASCII names to
IDN-unaware clients.

> For those who think it is too expensive to do nameprep in the server
> (it is not for areas like latin, greek or cyrillic) to have most names
> in queries being nameprepped might reduce the burden on the server.
> That depend on if a already nameprepped name can quickly be checked.

I suspect that the cost of doing nameprep depends on the length of the
string, but not much on its contents.  I doubt that checking whether a
name is nameprep'd is much cheaper than performing nameprep on it.

AMC