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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>


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:"  
> 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).

Received on Monday, 20 October 2008 23:20:49 UTC

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