W3C home > Mailing lists > Public > public-xg-webid@w3.org > June 2011

Re: [foaf-protocols] WebID test suite

From: Matt DeMoss <demoss.matt@gmail.com>
Date: Fri, 24 Jun 2011 16:45:46 -0400
Message-ID: <BANLkTi=E-vFopiHpcHiS4QSbDyKHnso9yg@mail.gmail.com>
To: Henry Story <henry.story@bblfish.net>
Cc: Kingsley Idehen <kidehen@openlinksw.com>, public-xg-webid@w3.org
>Its spec concepttually little or no different to using a directory object from ldap, looking for existance of a cert value in the directory attribute..

>that is why I distinguish - and we should distinguish more clearly in the spec - between a claimed WebID and a verified one. A WebID presented in the SAN fields of an X509 certificate is a claimed WebID.
The Relying Party/IDP then fetches the canonical document for each WebID

I find the contrast with a directory object to be particularly
interesting. It's usually the case that the CA is trusted to sign a DN
that corresponds to a directory object in a directory we trust to have
the correct attributes, but I would be interested to know more about
other systems where (as with WebID) the trust relationship is a bit
different. Do any of the SAML profiles do something you would consider

On Fri, Jun 24, 2011 at 4:31 PM, Henry Story <henry.story@bblfish.net> wrote:
> On 24 Jun 2011, at 22:00, Kingsley Idehen wrote:
> On 6/24/11 7:08 PM, Peter Williams wrote:
> The defacto owl sameAs part is really interesting (and its the semweb part
> of webid that most interests me, since its about the potential logic of
> enforcement....)
> are we saying that should n URIs be present in a cert and one of them
> validates to the satisfaction of the verifying party, then this combination
> of events is the statement: verifer says owl:sameAs x, where x is each
> member of the set of SAN URIs in the cert, whether or not all x were
> verified .
> No.
> When an IdP is presented with a Cert, it is going to have its own heuristic
> for picking one WebID. Now, when there are several to choose from I would
> expect that any choice results in a path to a Public Key -> WebID match.
> Basically, inference such as owl:sameAs would occur within the realm of the
> IdP that verifiers a WebID. Such inference cannot be based on the existence
> of multiple URIs serving as WebIDs in SAN (or anywhere else).
> Yes, that is why I distinguish - and we should distinguish more clearly in
> the spec - between a claimed WebID and a verified one. A WebID presented in
> the SAN fields of an X509 certificate is a claimed WebID.
> The Relying Party/IDP then fetches the canonical document for each WebID.
> These documents define the meaning of the WebID, of that URI, via a
> definitive description tying the URI to knowledge of the private key of the
> public key published in the certificate.
> If the meaning of two or more URIs is tied to knowledge of the same public
> key, then the relying agent has proven of each of these URIs that its
> referent is the agent at the end of the https connection. Since that is one
> agent, the two URIs refer to the same thing.
> Thats quite a claim to make. An more restrcitied claim could be that
> Yes, but I don't believe the spec infers that.
> verifier says webid says owl:sameAs x, where x is each member of the set of
> SAN URIs in the cert, whether or not all x were verified .
> No, don't think that's the implication from spec or what one would expect to
> happen.
> Kingsley
> ________________________________
> From: henry.story@bblfish.net
> Date: Fri, 24 Jun 2011 19:12:59 +0200
> CC: public-xg-webid@w3.org; foaf-protocols@lists.foaf-project.org
> To: home_pw@msn.com
> Subject: Re: [foaf-protocols] WebID test suite
> On 24 Jun 2011, at 18:45, Peter Williams wrote:
> one thing the spec does not state is what is correct behaviour when a
> consumer is prersented with a cert with multiple SAN URIs.
> Well it does say something, even if perhaps not in the best way. It says:
> in 3.1.4
> "The Verification Agent must attempt to verify the public key information
> associated with at least one of the claimed WebID URIs. The Verification
> Agent may attempt to verify more than one claimed WebID URI."
> then in 3.1.7
> If the public key in the Identification Certificate matches one in the set
> given by the profile document graph given above then the Verification
> Agentknows that the Identification Agent is indeed identified by the WebID
> URI.
> I think the language that was going to be used for this was the language of
> "Claimed WebIDs" - the SANs in the certificate, which each get verified. The
> verified WebIDs are the ones the server can use to identify the user. They
> are de-facto owl:sameAs each other.
> If the test suite is run at site A (that cannot connect to a particular part
> of the interent, becuase of proxy rules) presumably the test suite would
> provide a different result to another site which can perform an act of
> de-referencing.
> That is ok, the server would state declaratively which WebIDs were claimed
> and which were verified. It could state why it could not verify one of the
> WebIDs. Network problems is a fact of life, less likely than strikes in
> France - though those have been not been happening that often recently - or
> congestions on the road.
> This is a general issue. The degenrate case occurs for 1 SAN URI, obviously
> - since siteA may not be able to connect to its agent. Thus, the issue of 1
> or more multiple URIs is perhaps not the essential requirement at issue.
> A variation of the topic occurs when a given site (B say) is using a caching
> proxy, that returns a cached copy of a webid document (even though that
> document may have been removed from the web). This is the topic of trusted
> caches, upon which it seems that webid depends.
> That is what the meta testing agent will be able to tell. He will be able to
> put up WebID profiles log in somewhere, then login a few days later after
> having removed the profile, or changed it and report on how the servers
> respond.
>  We would look silly if the average site grants access to a resource when
> the identity document has been removed from the web,
> It all depends on what the cache control statements on the WebID Profile
> says. If they state they should last a year, then it is partly the fault of
> the WebID profile publisher. (Could Web Servers offer buttons to their users
> to update a cache?)
> In any case it also depends on how serious the transaction is. In a serious
> transaction it might be worth doing a quick check right before the
> transaction, just in case.
> yet cache continue to make consuemr believe that the identity is valid. At
> the same time, given the comments from the US identity conference (that
> pinging the internet during a de-referencing act is probably
> unsunstainable), caches seem to be required (so consuming sites dont
> generate observable network activity).
> WebID works with caches. I don't think we could think without. Even X509
> works with caches as is, since really an X509 signed cert is just a cache of
> the one offered by the CA.
> This all seems to be pointing at the issue that we have a trusted cache
> issue at the heart of the webid proposal, and of course we all know that the
> general web is supposed to be a (semi-trusted at best) cache.
> Caches need to be taken into account. But I don't see this as a major
> problem.
>> From: henry.story@bblfish.net
>> Date: Fri, 24 Jun 2011 13:37:26 +0200
>> CC: foaf-protocols@lists.foaf-project.org
>> To: public-xg-webid@w3.org
>> Subject: WebID test suite
>> Hi,
>> In the spirit of test driven development, and in order to increate the
>> rate at which we can evolve WebID, we need to develop test suites and
>> reports based on those test suites.
>> I put up a wiki page describing where we are now, where we want to go.
>> http://www.w3.org/2005/Incubator/webid/wiki/Test_Suite#
>> Please don't hesitate to improve it, and place your own library test end
>> points up there - even if they
>> are only human readable.
>> The next thing is to look at the EARL ontology I wrote and see if your
>> library can also generate a test report, that folows the lead of the one I
>> put up on bblfish.net. I expect a lot of detailed criticism, because I did
>> just hack this together. As others implement their test reports, and as
>> bergi builds his meta tests we will quickly notice our disagreements, and so
>> be able to discuss them, and put the results into the spec.
>> Henry
>> Social Web Architect
>> http://bblfish.net/
> _______________________________________________
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> http://bblfish.net/
> --
> Regards,
> Kingsley Idehen	
> President & CEO
> OpenLink Software
> Web: http://www.openlinksw.com
> Weblog: http://www.openlinksw.com/blog/~kidehen
> Twitter/Identi.ca: kidehen
> Social Web Architect
> http://bblfish.net/
Received on Sunday, 26 June 2011 12:37:38 UTC

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