Re: [idn] Reality Check

[Dan Oscarsson <Dan.Oscarsson@trab.se>]

Adam M. Costello wrote:


>> What does the normal human beings of the real world expect from DNS?
>> The semantics of current DNS says:
>> - a name can have mixed upper and lower case letters
>> - names will be matched case insensitively
>> IDNA says:
>> - a name can only be in lower case
>> - names will be matched exactly
>> So IDNA breaks current semantics of DNS.
>
>No, IDNA does not say that.  Application protocols can transmit
>names in non-nameprep'd mixed-case form.  Applications can store
>and display names in non-nameprep'd mixed-case form.  The only
>time it is necessary to apply nameprep is just before comparing
>two names.  Nameprep is mainly just a way to do case-insensitive
>alternate-represenation-insensitive comparisons.
>

IDNA indirectely says the above!
IDNA says that over the DNS protocol namepreped ACE must be used.
Because of this, DNS can only return names in lower case.
So, while you can enter mixed case, the moment a name is sent or
received over the DNS protocol it is converted into lower case and
the mixed case information is lost.

   Dan