Re: [idn] nameprep in application may break things

[Patrik Fältström <paf@cisco.com>]

At 15.02 +0100 01-02-07, Dan Oscarsson wrote:
>I think having nameprep done in applications will break things.
>
>If you do: nslookup Www.cisco.com
>you get as an answer:
>Name:    WWW.cisco.com
>Address:  198.133.219.25
>
>If you do: nslookup Www.cisco.com
>you get as an answer:
>Name:    Www.cisco.com
>Address:  198.133.219.25
>
>
>If you had nameprep in nslookup the answer in both cases would be:
>Name:    www.cisco.com
>Address:  198.133.219.25
>
>
>This will break all scripts calling nslookup and the doing simple
>string matching in the answer to test the result.
>I am sure there are lots of scripts that expect this behaviour.

One thing you forget is that applications which handle domainnames
need to do nameprep, including your "simple script".

Also, I question whether a DNS server rewrite the query part of a DNS
packet. I doubt any DNS server do that.

Further, I don't understand what you mean by your conclusion. Why
should nslookup not present the non-nameprepped string to the user?
You seem to think that nslookup is displaying the string which is the
output of the nameprep calculation, but it could aswell be the input.

   paf


--
Patrik Fältström <paf@cisco.com>                         Cisco Systems
Consulting Engineer                                  Office of the CSO
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