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RE: Question on canonicalization and namespaces

From: Spielman, Terence <TSpielma@inovant.com>
Date: Mon, 30 Sep 2002 08:05:20 -0700
Message-ID: <A38C0F5A6E195C48AC2C93BEC33EF83D54FFD4@sw745x043.visa.com>
To: "'Christian Geuer-Pollmann'" <geuer-pollmann@nue.et-inf.uni-siegen.de>, "Spielman, Terence" <TSpielma@inovant.com>, "'w3c-ietf-xmldsig@w3.org'" <w3c-ietf-xmldsig@w3.org>
Cc: "'reagle@w3.org'" <reagle@w3.org>

Sorry to revive a dead topic, but it's been pointed out to me
that the answer I received on this list might be erroneous.

> > If anyone could quickly answer the following yes/no questions as
> > well, I would appreciate it.  Based on my readings of the specs
> > (XML, Namespaces, XMLDSIG), my answers are in square brackets.
> >
> > 1) Is it required that the Signature element have a namespace
> >    node with a value of "http://www.w3.org/2000/09/xmldsig#"?
> >    [No if the XML need only be well-formed and Yes otherwise]
> 
> Yes. The Signature element must be bound to that namespace. 
> This can look 
> like this:
> 
> <Signature xmlns="http://www.w3.org/2000/09/xmldsig#" >...</Signature>
> 
> <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#" 
> >...</ds:Signature>
> 
> or even
> 
> <doc xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
>    <ds:Signature>....</ds:Signature>
> </doc>
> 
> In the latter case, there is no DOM node (no 'Attribute') in the 
> ds:Signature element, but the namespace is in scope.
> 

I understand both of these example, in which the namespace is
eitehr explicitly declared in the Signature element or inherited,
but the XML DSIG DTD states the following:

   <!ATTLIST Signature  
    xmlns   CDATA   #FIXED 'http://www.w3.org/2000/09/xmldsig#'
    Id      ID  #IMPLIED >

And #FIXED means that if the xmlns is omitted, it will take the value of
specified above.  This would lead me to believe that the xmlns attribute
does NOT explicitly need to be included or inherited.  Although this does
disturb me.  Can anyone set me straight?

Thanks!
Terence
Received on Monday, 30 September 2002 11:07:48 UTC

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