ISSUE-110 (visibly utilizes in Exc-C14N): Need better definition for "visibly utilizes" in Exc-C14N [Maint-ExC14N (Exclusive XML Canonicalization Version 1.0 Maintenance)]

ISSUE-110 (visibly utilizes in Exc-C14N): Need better definition for "visibly utilizes" in Exc-C14N [Maint-ExC14N (Exclusive XML Canonicalization Version 1.0 Maintenance)]

http://www.w3.org/2008/xmlsec/track/issues/110

Raised by: Brian LaMacchia
On product: Maint-ExC14N (Exclusive XML Canonicalization Version 1.0 Maintenance)

The specification contains a definition of “visibly utilizes” at http://www.w3.org/TR/xml-exc-c14n/#def-visibly-utilizes which reads:

An element E in a document subset visibly utilizes a namespace declaration, i.e. a namespace prefix P and bound value V, if E or an attribute node in the document subset with parent E has a qualified name in which P is the namespace prefix. A similar definition applies for an element E in a document subset that visibly utilizes the default namespace declaration, which occurs if E has no namespace prefix.

The phrase "an attribute node in the document subset with parent E" is unclear.  I believe the correct interpretation is supposed to be “any node on element E’s attribute axis”.  However, a possible alternative interpretation is 
that the relevant nodes could include all attributes of E and those of any element with ancestor E.  This alternative interpretation leads to canonicalization placing all namespace declarations on a root node, except where overrides are required.

We should fix the text so that it is clear that "visibly utilizes" means ((an attribute node in the document subset) with parent E) and not (an attribute node (in the document subset with parent E)).

Received on Thursday, 12 March 2009 23:40:37 UTC