Re: [Uri-review] [hybi] ws: and wss: schemes

["Martin J. Dürst"]

On 2009/09/17 20:39, Julian Reschke wrote:
> Ian Hickson wrote:

>> Encoding considerations.
>> Characters in the host component that are excluded by the syntax
>> defined above must be converted from Unicode to ASCII by applying
>> the IDNA ToASCII algorithm to the Unicode host name, with both the
>> AllowUnassigned and UseSTD3ASCIIRules flags set, and using the
>> result of this algorithm as the host in the URI.

I think this has various problems.

First, it is fixed to IDNA 2003 (I think I may have said this already).
IDNA 2008 is around the door. It doesn't use terms such as "ToASCII" or
"AllowUnassigned".

Second, if this is about resolution (rather than about generic
conversion), and because this is a new scheme, it should not exclude the
case that some part of a domain name (reg-name) is percent-encoded,
because both RFC 3986 and 3987 allow this.

Third, wording this as "characters" seems to say that this is a
character-by-character operation, or that it might be applied to
subsequent non-ASCII characters in groups, but ToASCII, when used, has
to be applied to whole labels, not characters.

Fourth, as http://tools.ietf.org/html/draft-iab-idn-encoding-00 shows in
more detail, assuming that DNS is always used for resolution of
reg-names, and the technology will never be used e.g. on intranets with
other resolution services seems to be unnecessarily restrictive.

Ideally, all the above points should be addressed by some work on the
IRI front (public-iri@... cc'ed), but that work isn't done yet.

>> Characters in other components that are excluded by the syntax
>> defined above must be converted from Unicode to ASCII by first
>> encoding the characters as UTF-8 and then replacing the
>> corresponding bytes using their percent-encoded form as defined in
>> the URI and IRI specification. [RFC3986] [RFC3987]
>
> I think that's good, except that the mention of IRI in the last sentence
> seems to be superfluous. RFC3986 already defines everything that is
> needed here. Or is there something specific from the IRI spec you think
> is relevant? (In which case it should state that more clearly).

RFC 3986 indeed defines how to use %-encoding, but except for domain
names (which are not involved in this case), it does not specify UTF-8,
which is only done in RFC 3987.

Regards,    Martin.

--
#-# Martin J. Dürst, Professor, Aoyama Gakuin University
#-# http://www.sw.it.aoyama.ac.jp   mailto:duerst@...

[Ian Hickson]

On Thu, 17 Sep 2009, Julian Reschke wrote:

>
> It now says:
>
> >    Encoding considerations.
> >       Characters in the host component that are excluded by the syntax
> >       defined above must be converted from Unicode to ASCII by applying
> >       the IDNA ToASCII algorithm to the Unicode host name, with both the
> >       AllowUnassigned and UseSTD3ASCIIRules flags set, and using the
> >       result of this algorithm as the host in the URI.
> >
> >       Characters in other components that are excluded by the syntax
> >       defined above must be converted from Unicode to ASCII by first
> >       encoding the characters as UTF-8 and then replacing the
> >       corresponding bytes using their percent-encoded form as defined in
> >       the URI and IRI specification.  [RFC3986] [RFC3987]
>
> I think that's good, except that the mention of IRI in the last sentence
> seems to be superfluous. RFC3986 already defines everything that is
> needed here. Or is there something specific from the IRI spec you think
> is relevant? (In which case it should state that more clearly).

I think referencing IRI for the paragraph that talks about how to process
IRIs is helpful, even if not strictly necessary. (As Martin later pointed
out, though, in general, how to convert Unicode to UTF-8 to percent
escapes appears to be defined in 3987, not 3986.)


On Fri, 18 Sep 2009, "Martin J. D�rst" wrote:
>
> I think this has various problems.
>
> First, it is fixed to IDNA 2003 (I think I may have said this already).
> IDNA 2008 is around the door. It doesn't use terms such as "ToASCII" or
> "AllowUnassigned".

What are the magic terms that we should use instead? (This will affect
HTML5 also; any advice on how to fix the terminology there would be very
welcome also.)


> Second, if this is about resolution (rather than about generic
> conversion), and because this is a new scheme, it should not exclude the
> case that some part of a domain name (reg-name) is percent-encoded,
> because both RFC 3986 and 3987 allow this.

Not sure what you mean here.


> Third, wording this as "characters" seems to say that this is a
> character-by-character operation, or that it might be applied to
> subsequent non-ASCII characters in groups, but ToASCII, when used, has
> to be applied to whole labels, not characters.

The paragraph applies it to the whole hostname.


> Fourth, as http://tools.ietf.org/html/draft-iab-idn-encoding-00 shows in
> more detail, assuming that DNS is always used for resolution of
> reg-names, and the technology will never be used e.g. on intranets with
> other resolution services seems to be unnecessarily restrictive.

Not sure what you mean here.


> Ideally, all the above points should be addressed by some work on the
> IRI front (public-iri@... cc'ed), but that work isn't done yet.

That would indeed be ideal.

--
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'