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Re: XML Canonicalization and "xml:" XML namespace declarations

From: Hoylen Sue <hoylen@hoylen.com>
Date: Tue, 21 Oct 2008 09:20:07 +1000
Cc: XMLSec WG Public List <public-xmlsec@w3.org>, public-xmlsec-comments@w3.org, www-xml-canonicalization-comments@w3.org
Message-Id: <E9FA00C3-D6F0-4E60-8419-1DBDC45E3BCB@hoylen.com>
To: Konrad Lanz <Konrad.Lanz@iaik.tugraz.at>

Konrad,

You are correct: the current specification does address the handling  
of "xml:" XML namespace declarations.  Thank you for pointing out the  
relevant section to me.

> Hoylen Sue wrote:
>> In its maintenance of the XML Canonicalization and Exclusive XML
>> Canonicalization specifications, could the Working Group please
>> explicitly clarify how  declarations of the "xml:" XML namespace are
>> to be handled?
>
> Thanks for your comment, we do think however that the current spec  
> gives
> sufficient guidance about what happens to declarations of the "xml:"  
> XML
> namespace.
>
> The Processing Model of Canonical XML (C14n)
> http://www.w3.org/TR/xml-c14n.html#ProcessingModel states:
>> To finish processing L, simply process every namespace node in L,
>> except omit namespace node with local name xml, which defines the xml
>> prefix, if its string value is http://www.w3.org/XML/1998/namespace.
>
> Which means that these namespace declarations are never rendered in  
> the
> canonical form.

The only oddity in the phrasing is where it says "if its string value  
is http://www.w3.org/XML/1998/namespace".  From my interpretation of  
the XML Namespace 1.1  Recommendation, the string value will always be  
that value, so this "if" will always be true.

<http://www.w3.org/TR/xml-names11/> contains:
The prefix xml is by definition bound to the namespace name http://www.w3.org/XML/1998/namespace 
. It MAY, but need not, be declared, and MUST NOT be undeclared or  
bound to any other namespace name.

This is not a problem, and I must admit that having the namespace name  
mentioned explicitly is very good (for searching on this topic, since  
searching for the prefix "xml" brings up too many false positives).

Hoylen
-- 
http://www.hoylen.com/
Received on Monday, 20 October 2008 23:20:48 GMT

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