[jdev] Re: stringprep, was: Case sensitive & jid

[maqi at jabberstudio.org]

On Fri, 7 May 2004, Matthias Wimmer wrote:

> None of the parts are case-sensitive and non of them are
> case-insensitive. You have to use different string-prep profiles to
> check if two are the same.

A little bit more info is probably good here.

For example, a problem with standard lowercase comparison is that it fails
with many non-english languages. Stringprep is more or less a way to
provide standardization of strings similar to lowercasing.

References:

RFC 3454, http://www.faqs.org/rfcs/rfc3454.html
"This document describes a framework for preparing Unicode text
strings in order to increase the likelihood that string input and
string comparison work in ways that make sense for typical users
throughout the world.  The stringprep protocol is useful for protocol
identifier values, company and personal names, internationalized
domain names, and other text strings."

Usage of stringprep is mandatory for XMPP, see
http://www.jabber.org/ietf/draft-ietf-xmpp-core-23.txt
(search for "stringprep").

Concerning jabberd14:
jabberd 1.4.3 does not use stringprep (it uses lowercasing and therefore
for example treats MÜLLER at jabber.org as a different user than
müller at jabber.org). jabberd14-CVS however supports stringprep by using the
libidn library (thanks to Matthias Wimmer, "configure --enable-idn").

Regards