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RE: Clarifying XPath Filtering Transform text (pertains to Action-350, etc.)

From: Scott Cantor <cantor.2@osu.edu>
Date: Tue, 28 Jul 2009 18:19:45 -0400
To: <edsimon@xmlsec.com>, "'XMLSec WG Public List'" <public-xmlsec@w3.org>
Message-ID: <01b901ca0fd1$839daa50$8ad8fef0$@2@osu.edu>
Ed Simon wrote on 2009-07-28:
> The English language, alas, makes it a little ambiguous as to whether
> this means an XPath node-set has to be a well-formed XML document or
> only octet streams have to be well-formed XML documents. My
> understanding is that it is generally taken that the input has to be a
> well-formed XML document whether it is an XPath node-set or an octet
> stream. (If so, we should clarify that in the Canonicalization
> specification.)

Pretty (as in 100%) sure that's NOT the case. C14N is such a pain because
it's NOT assumed to be anything but a totally arbitrary node set. In the
octet stream case, it's a well-formed document, but not otherwise.

> I also believe it would be sensible to support XPath expressions that
> return generic XPath node sets. I'm guessing most implementations do
> this but I'd like to hear how. For example, what is the prescribed
> treatment of the following examples of node sets returned by an XPath
> Filtering transform in order to produce a hashable octet stream?:

In all cases, you apply c14n. I think you got lost because you took a wrong
turn on the input rules there.

-- Scott
Received on Tuesday, 28 July 2009 22:20:29 UTC

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