RE: [xri] FW: Dereferencing rules are required for interop

["Drummond Reed" <drummond.reed@cordance.net>]

[Just a metanote that while I understand the arguments here and I remember
the discussions about this with Steve, it's been long enough that I need
time to go back and reconstruct them. It's too close to bed to do that
tonight. I'll try to follow through first thing in the morning. =Drummond]

> -----Original Message-----
> From: Steven Churchill [mailto:steven.churchill@xdi.org]
> Sent: Tuesday, August 21, 2007 4:31 PM
> To: 'Tan, William'; 'Markus Sabadello'
> Cc: xri@lists.oasis-open.org
> Subject: RE: [xri] FW: Dereferencing rules are required for interop
> 
> 
> Wil,
> 
> I'm not following the first part of your argument. If you're interested in
> my thoughts about this, please clarify, or give me a call or something.
> 
> You said:
> > Specifying that the CID query parameter affects the decision of whether
> > to follow a Ref or not kind of imposes equivalence semantics onto Refs,
> > which we are trying to separate.
> 
> To visualize what's going on here, take a look at figure 5 in
> <http://www.oasis-open.org/committees/download.php/22395/xri-polyarchy-
> artic
> le.pdf>.
> 
> The issue is whether or not the Resolver returns (1) an XRD describing the
> red node or (2) an XRD describing the black node in lower right corner.
> 
> Say that the client has addressed the red node using the identifier
> @xdi*andy.dale and specified resolver parameter sep=false. Drummond
> proposed
> last fall (and I think rightly so) that the existence of the CID should
> interplay with the cid=true behavior. The table captures this interplay.
> For
> example, if the red node's XRD does not contain a CID, then cid=false will
> cause the red node's metadata to be returned whereas cid=true will cause
> the
> black node's.
> 
> Again, I will leave it to Drummond to defend that proposal. (If he
> doesn't,
> then I will chime in later on his behalf--if I can remember all the
> details.)
> 
> ~ Steve
> 
> 
> 
> 
> -----Original Message-----
> From: Tan, William [mailto:William.Tan@neustar.biz]
> Sent: Tuesday, August 21, 2007 2:25 PM
> To: Markus Sabadello
> Cc: Steven Churchill; xri@lists.oasis-open.org
> Subject: Re: [xri] FW: Dereferencing rules are required for interop
> 
> I think I agree with Markus, and maybe this is where my opinion about
> CID verification differs from Steve's.
> 
> With the original motivating use case of CID verification in mind, which
> is to prevent one authority from spoofing another authority's CID from
> another part of the tree. /Ideally, /clients using a /proxy resolver/
> would just request for a filtered XRD using
> _xrd_r=application/xrd+xml%3Bsep=true%3Brefs=true%3Bcid=true
> And if clients has only this choice (of using a proxy resolver and can
> only make a single call), the side effect is that you have the take the
> CID from the final XRD in the entire resolved XRDS. It also has the
> interesting effect of allowing a model whereby a client will use as
> primary key the CID of =steven.churchill when @ootao*steve contains a
> Ref to =steven.churchill's CID. This may not suit the model for all
> client applications that consume XRIs, but a certain class of
> application may want to specify this particular behavior. IMO specifying
> this is out of the scope of the resolution specs.
> 
> Specifying that the CID query parameter affects the decision of whether
> to follow a Ref or not kind of imposes equivalence semantics onto Refs,
> which we are trying to separate.
> 
> =wil
> 
> Markus Sabadello wrote:
> > Hey Steve,
> >
> > Are you sure about lines 3 and 5 in the table? Should a Ref be
> > dereferenced just because there is no CID in the XRD? Even if there is
> > a matching SEP?
> >
> > My understanding of CID verification was that it simply verifies a CID
> > (if there is one), not influence the resolution process, but maybe I
> > was wrong. Maybe its purpose is more like "give your best to find me a
> > verified CID".
> >
> > Markus
> >
> > On 8/21/07, *Steven Churchill* <steven.churchill@xdi.org
> > <mailto:steven.churchill@xdi.org>> wrote:
> >
> >     Woops. I sent this to the list last week but it bounced due to my
> >     not using my xdi.org <http://xdi.org> account.
> >
> >
> >
> >
> ------------------------------------------------------------------------
> >
> >     *From:* Steve Churchill [mailto:steven.churchill@ootao.com
> >     <mailto:steven.churchill@ootao.com>]
> >     *Sent:* Friday, August 17, 2007 12:10 PM
> >     *To:* 'xri@lists.oasis-open.org <mailto:xri@lists.oasis-open.org>'
> >     *Subject:* Dereferencing rules are required for interop
> >
> >
> >
> >     Drummond,
> >
> >
> >
> >     I've sent this document to you at least twice already. It does not
> >     appear in the spec.
> >
> >
> >
> >     If you do not feel that this specificity is absolutely required
> >     for interoperability, then please explain why.
> >
> >
> >
> >     ~ Steve
> >
> >
> >
> >
> >
> >
> >