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Re: Dereferencing a Reference with no URI attribute

From: Sean Mullan <sean.mullan@sun.com>
Date: Mon, 09 Dec 2002 11:11:00 +0000
Message-ID: <3DF47A44.DB616E0C@sun.com>
To: Joseph Reagle <reagle@w3.org>
Cc: w3c-ietf-xmldsig@w3.org

Joseph Reagle wrote:
> 
> On Friday 06 December 2002 09:51 am, Sean Mullan wrote:
> > I have a question about dereferencing (or identifying)
> > a Reference without a URI attribute. Section 4.3.3.1 of
> > xmldsig-core states, 4th paragraph:
> >
> > "If the URI attribute is omitted altogether, the receiving
> > application is expected to know the identity of the object".
> >
> > Further on, in section 4.3.3.2, it states:
> >
> > "Unless the URI-Reference is a 'same-document' reference as defined
> > in [URI, Section 4.2], the result of dereferencing the URI-Reference
> > MUST be an octet stream."
> >
> > Does the statement above apply to a Reference with no URI
> > attribute?
> 
> Interesting question, from the text my initial reading is that an "implicit
> same-document reference" is not precluded. If fact, I'd expect this might
> be common in the context of implicit references.
> 
> > Can it be represented as either an octet stream or
> > a node set? Or, since it is undefined, is it technically NOT a
> > same-document reference, and therefore MUST be dereferenced/identified
> > as an octet stream?
> 
> While an interesting question, is this motivated by an actual example? I'm
> wondering about the interop implications of this. For example, if I had a
> signature with an implicit reference to a node-set, the first transform
> might require a node-set for processing. Is this a problem? I don't see how
> as the other side is already expected to know what the initial object is
> (i.e., node-set).

The question is not motivated by any specific example; I just wanted to make
sure that I was strictly abiding by the specification, which seemed a little 
unclear to me. I'll assume a Reference w/o a URI attribute can implicitly 
refer to either a node-set or octet stream.

Thanks,
Sean
Received on Monday, 9 December 2002 06:12:56 GMT

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