RE: [xri] Removing ds elements from schema (was: OpenID Delegating relationship in XRD)

["Scott Cantor" <cantor.2@osu.edu>]

Will Norris wrote on 2009-09-08:
> I'm actually really interested in pursuing this a bit more as well.
> It would allow us to use the original content model we had, but in a
> way that works with XSD.  Interestingly, if we don't include the ds:*
> elements as part of the XRD schema, it would solve the problem we had
> with RelaxNG since there is no longer a schema dependence on XML
> DSig.  (Not that I'm necessarily advocating a switch back to RelaxNG
> at this point).

Sorry I didn't think of it originally. I imagine it wouldn't be all that
hard to get one written based on the original one.
 
> The other big question is the placement of ds:Signature.  I completely
> understand Scott's argument for placing it higher up in the document.
> This change we're discussing would mean that the Signature could now
> appear anywhere in the document.  Scott, how much of a concern is this
> really?

It's not only that, it's also limiting the number to one. While it sometimes
comes up to support multiple signatures, that's somewhat complex in practice
(because of signature ordering).

> The idea of placing it higher is so that XML processors would
> know early on if they needed to be doing canonicalization.  How many
> processors actually alter their behavior in the presence of the
> Signature element in this way?

It's for streaming implementations.

> I'm fairly certain the Java version of
> XML-Tooling does not.  How about the C version?

We're exclusively DOM-based, so we don't care.

> We could always
> recommend that XRD providers place the Signature element higher up in
> the document.

True.

-- Scott