Fwd: "International Domain Names" support in KDE

Marc Mutz Marc.Mutz at uni-bielefeld.de
Tue Jan 28 00:16:14 GMT 2003


On Tuesday 28 January 2003 00:40, Thiago Macieira wrote:
> The documents are actually very specific about this: IDN changes ONLY
> the hostname part of the records. The mail account, for instance, is
> not changed at all and the RFCs still state that it's restricted to
> US-ASCII.
<snip>

I'm not talking about the IDN RFC's here. rfc2822bis will need to define 
what encoding should be used when a domain production is going to be 
applied to a IDN. Chances are (from discussions on ietf-822 at imc.org) 
that this will be punycode. Then, the next step is that people will 
want to have localized local-part's. And the tendency is to use 
punycode (or a variant without casemapping, since local-part is in 
theoery case-sensitive, though in praxi it mostly isn't) for that, too, 
and _not_ rfc2047.

> In the case of e-mail, the domain name found in the headers of the
> message, my guess is it should be encoded like subjects or like names
> (not e-mail addresses) are currently done. Only the SMTP conversation
> will require ACE, and that is if ESMTP doesn't specify later on that
> UTF-8 is to be used.

See above. RFC2047 was designed for display purposes. Requiring the 
final MTA to realize that =?us-ascii?q?marc_mutz?=, "marc mutz", 
=?utf-8?b?bWFyYyBtdXR6?= all refer to the same mailbox is a tad hard 
and backwards-incompatible, isn't it?

UTF-8 also has a similar problem if you don't enforce a particular 
on-the-wire normalization. And you'd still have to hope that the SMTP 
server groks the 8bit characters (esp utf-8 is fragile, since it uses 
8bit-codepoints that are unassigned in latin1. I only say "sendmail" 
here...) And if you dealed with all that, you can as well use punycode.

Hope that makes it clear why KMail (and other apps) will have to deal 
with IDN non-transparently.

Marc

-- 
Silent leges inter arma      -- Cicero
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: signature
URL: <http://mail.kde.org/pipermail/kde-core-devel/attachments/20030128/002472e8/attachment.sig>


More information about the kde-core-devel mailing list