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Re: Errors in the XML-Signature spec. examples (Namespace defaulting for attributes)

From: Donald E. Eastlake 3rd <dee3@torque.pothole.com>
Date: Fri, 11 Aug 2000 08:14:38 -0400
Message-Id: <200008111214.IAA05009@torque.pothole.com>
To: "Gregor Karlinger" <gregor.karlinger@iaik.at>
cc: "XML" <w3c-ietf-xmldsig@w3.org>

Is this really a problem?  I thought that attributes without namespace
prefixes were automatically considered within the context of the
element where they occur.  In effect, the namespace qualified name of
the element is the default "namespace" for attributes of that element.

Take the first exampe in section 5.2 of the Namespaces document which
you point to.  It has an <a> element using the default namespace of
http://www.w3.org/TR/REC-html40.  This element has an href attribute.
How are you supposed to understand what that attribute means unless
you consider it to, in some sense, be in the "namespace" of the
element where it occurs?  I.E., that it is part of the "Per Element
Partition" defined in section A.2 of the Namespaces document.

In your example below, just saying "Id" is, in effect, saying
"XMLSignature:Signature:Id" except that syntax is prohibited...

Presumably this is the reason for the odd wording:
"Note that default namespaces do not apply directly to attributes."
                                           --------

Donald

From:  "Gregor Karlinger" <gregor.karlinger@iaik.at>
To:  "XML" <w3c-ietf-xmldsig@w3.org>
Date:  Fri, 11 Aug 2000 12:21:04 +0200
Message-ID:  <NDBBIMACDKCOPBLEJCCDMEHNCJAA.gregor.karlinger@iaik.at>

>Hi Joseph & Merlin,
>
>while trying to verify Merlins signature examples with our implementation,
>I detected the following problem, which applies to Merlins examples as
>well as to the examples in the XML-Signature specification in chapter 2.
>
>All the examples are constructed in the following way: A default namespace
>attribute is declared in the Signature element (see line [s01] in chapter
>2.1),
>which should apply to all descendants as well.
>
>The problem is, that a default namespace does not apply to descendant
>attributes, but only descendant elements
>(see http://www.w3.org/TR/REC-xml-names/#defaulting).
>
>I suggest to assign the XML-Signature namespace via a explicit namespace
>attribute (line [s01] could look like
>
>  <XMLSignature:Signature
>    XMLSignature:Id="MyFirstSignature"
>    xmlns:XMLSignature="http://www.w3.org/2000/07/xmldsig#">
>
>Regards, Gregor
>---------------------------------------------------------------
>Gregor Karlinger
>mailto://gregor.karlinger@iaik.at
>http://www.iaik.at
>Phone +43 316 873 5541
>Institute for Applied Information Processing and Communications
>Austria
>---------------------------------------------------------------
>
>
Received on Friday, 11 August 2000 08:12:09 GMT

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