RE: FW: Clarification sought re C14N11

I embed two comments below (both requesting feedback).

> -----Original Message-----
> From: public-xml-core-wg-request@w3.org 
> [mailto:public-xml-core-wg-request@w3.org] On Behalf Of Konrad Lanz
> Sent: Tuesday, 2007 August 21 16:28
> To: Thomas Roessler; Sean Mullan
> Cc: XMLSec; public-xml-core-wg
> Subject: Re: FW: Clarification sought re C14N11
> 
> Dear all,
> 
> I searched the list archive, and found the first draft for section 2.4
> in June 2006 [4]. Unfortunately I cannot exactly recall the 
> intention of
> that change. Nonetheless, looking at it today and todays 
> wording of the
> xml:base fix up, it makes perfect sense to revert this change.

Glenn, can you comment on this?

> 
> > The relevant change is in section 2.4, where the language 
> was changed
> > from:
> > 
> > The processing of an element node E MUST be modified 
> slightly when an
> > XPath node-set is given as input and the element's parent is omitted
> > from the node-set.
> > 
> > to:
> > 
> > The processing of an element node E MUST be modified 
> slightly when an
> > XPath node-set is given as input and some of the element's ancestors
> > are omitted from the node-set.
> 
> Thus, may I propose to do this fix together with the feedback from CR
> Testing ?
> 
> Looking at the current text of c14n 1.1 the reverting should not harm
> the processing of xml:base. It says
> 
> "... ancestor axis contains successive elements E1...En that 
> are omitted
> and E=En+1 is included"
> 
> implying that the parent (En) has been omitted.
> 
> 
> There is however a second point I'd like to discuss here, which needs
> some introduction and an example:
> 
> [4] was focused on the xml:base fix-up and hence lacked an 
> update to the
> ancestor axis examination step for simple inheritable attributes
> 
> cf.: "This examination is performed until the first rendered 
> occurrence
> exclusive ..."
> 
> As far as I recall intended to fix the idiosyncrasy of unnecessary
> copying of inheritable xml:base attributes in c14n.
> 
> Now, please consider the following example.
> 
> <e1 xml:lang="de" xml:base="http://www.example.org">
>   <e2>
>     <e3>
>       <e4/>
>     </e3>
>   </e2>
> </e1>
> 
> With <e2> being omitted this would result in
> 
> <e1 xml:lang="de" xml:base="http://www.example.org">
>   <e3 xml:lang="de" (xml:base="http://www.example.org")>
>       <e4/>
>     </e3>
> </e1>
> 
> (xml:base="http://www.example.org") is written in parenthesis to show
> that it wouldn't appear in c14n 1.1 .
> Without (xml:base="http://www.example.org") it should be the result
> according to the text in c14n 1.0 .
> 
> The following however would be more natural and may be an option for
> future versions of c14n.
> 
> <e1 xml:lang="de" xml:base="http://www.example.org">
>   <e3>
>       <e4/>
>     </e3>
> </e1>
> 
> The XML Security Maintenance Group might want to change this
> idiosyncrasy in a version post c14n 1.1 .
> 
> Keeping this idiosyncrasy in both versions C14n 1.0 and 1.1 however
> remains compatibility for documents not using xml:base or xml:id.
> 
> But then a question of consistency arises and we may want to have
> xml:base also being copied into an orphan. Just to be consistent with
> the other attributes in the xml namespace although it is not really
> necessary.
> 
> This may result in the following sentence being removed from the
> current c14n 1.1 text.
> 
> > Then fix-up is only performed if at least one of E1 ... En has an
> > xml:base attribute.
> 
> Assuming others also feel it's worth to achieve consistency 
> here, may I
> propose to consider such a change also as a result from CR-Testing ?
> 
> Any Thoughts?

I continue to prefer to avoid fiddling with wording beyond our
remit which was supposedly just to correct the invalid inheritance
of xml:id and xml:base.  We do not have the expertise or desire to
get into C14N further.

Regarding this particular point, I am not able to form an opinion,
so I request that others express their opinions as to whether such
a change would be appropriate to make as we produce the C14N 1.1 PR.

paul

> 
> Konrad
>
> [4]
http://lists.w3.org/Archives/Public/public-xml-core-wg/2006Jun/0032.html
> 
> Grosso, Paul schrieb:
> > Forwarding to XML Core with permission.
> > 
> > paul
> > 
> > -----Original Message----- From: Thomas Roessler [mailto:tlr@w3.org]
> >  Sent: Tuesday, 2007 August 21 10:55 To: Grosso, Paul;
> > Norman.Walsh@Sun.COM Cc: w3c-xml-cg@w3.org; Sean.Mullan@Sun.COM 
> > Subject: Clarification sought re C14N11
> > 
> > Paul, Norm,
> > 
> > Sean Mullan (CCed) noticed [3] that the C14N 1.1 CR [1] can be read 
> > in a way that would copy inheritable attributes to all 
> children of an
> > element if that element's parent have been removed. That behavior 
> > would be different from the one in C14N 1.0 [2].
> > 
> > The relevant change is in section 2.4, where the language 
> was changed
> > from:
> > 
> > The processing of an element node E MUST be modified 
> slightly when an
> > XPath node-set is given as input and the element's parent is omitted
> > from the node-set.
> > 
> > to:
> > 
> > The processing of an element node E MUST be modified 
> slightly when an
> > XPath node-set is given as input and some of the element's ancestors
> > are omitted from the node-set.
> > 
> > We are wondering whether this is an intentional change, and the 
> > behavior sketched at [3] is desired, or whether this was an 
> > inadvertent change, and the text is meant to describe the behavior 
> > known from C14N 1.0.  Preliminary discussion seems to suggest that 
> > people are leaning toward the latter interpretation; in 
> that case, it
> > might be worth cleaning up the text while considering CR feed-back.
> > 
> > Your guidance would be most welcome, to ensure that the 
> right kind of
> > guidance is provided to implementors in preparation for the interop
> > event.
> > 
> > 1. http://www.w3.org/TR/2007/CR-xml-c14n11-20070621/ 2.
> > http://www.w3.org/TR/xml-c14n 3. 
> > 
> http://lists.w3.org/Archives/Public/public-xmlsec-maintwg/2007
> Aug/0049.h
> >  tml
> > 
> > Regards,
> 
> 
> -- 
> Konrad Lanz, IAIK/SIC - Graz University of Technology
> Inffeldgasse 16a, 8010 Graz, Austria
> Tel: +43 316 873 5547
> Fax: +43 316 873 5520
> https://www.iaik.tugraz.at/aboutus/people/lanz
> http://jce.iaik.tugraz.at
> 
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>

Received on Monday, 27 August 2007 15:39:05 UTC