Some suggestions about Open Id AX profile

Wed Jun 3 10:26:29 UTC 2009

Hi Allen,

Validates looks fine!  . I will make an in-depth study.
The third option you propose looks fine too and the more straightforward in
some cases : If you've a doubt just ask the issuer.

It would work fine on some schemas. For example. If you're verifying user's
name or dob and user is providing a X509 certificate containing those
attributes you can check certificate status and request attributes to
certificate issuer.

This will make Certification Authority implement an OpenID endpoint serving
those kind of requests (the same way they're offering OCSP endpoints to deal
with certificate status).

For attributes like email, or those that could be included inside a
certificate or a signed assertion it would be "easy" to check with issuers
the value of those attributes.

But there are attributes were it's value doesn't identify issuer, but only
the owner. Attributes like for example mobile number where this number is
not bound to any issuer. To verify this attribute we could send an SMS with
a code and proceed to verify, but this should be performed by OP in order to
keep complexity at minimum at RP, so we need to trust OP.

I strongly agree with you that it would be nice to have a trust relation
made between RP and OP before starting attribute verification.  To help
establishing those relations it would be nice to have a way to determine the
quality of an OP (f.ex reputation, mechanisms like what
TSL<http://www.genghinieassociati.it/acrobat/it%20security/Standards/ETSI/tr_102030v010101p.pdf>is
for Certification Authorities... in the end a set of white/black
lists).

We currently have a service that allow RP to request users attributes like
name, dob, social security number, mobile number, email and all in a secure
way using verification tokens, X509 Certificates (using certificates from
some European and South America countries)... .

We're using our own protocol but we strongly want to join OpenId and
deprecate our current protocol. With AX verify and CX maybe we'll move to
OpenId soon.

Many thanks Allen. I'll keep waiting Contract Exchange and hope we could
help on the creation process.

Best regards

Dave

2009/6/3 Allen Tom <atom at yahoo-inc.com>

>  Hi David,
>
> There has been a lot of discussion about adding Attribute Metadata to AX
> 2.0, and this is within the charter of the proposed AX 2.0 Working Group.
>
> http://wiki.openid.net/OpenID_Attribute_Exchange_Extension_2_0
>
> One of the primary use cases driving this is to enable an OP to describe
> the user's email address. For instance, an email address returned via AX
> could just be a user-entered string that is totally unverified, or the email
> address could have been verified by the OP at some point in the past. A
> third option is that the OP is actually the user's email provider, and knows
> with 100% certainty that the user's email address is correct.
>
> However, Trust is out of scope for AX 2.0. The RP would have to already
> trust the OP to make claims about the validity of the user's attributes.
>
> The Contract Exchange WG is might be addressing your issue. I'm not quite
> sure what the status is on CX.
> http://wiki.openid.net/Working_Groups%3AContract_Exchange_1
>
> Allen
>
>
> David Garcia wrote:
>
> My company is starting a new Identity Management Service and we want to
> built it's AX interface over OpenId AX profile.
>
> I'll introduce myself at the very beginning. My name is Dave Garcia and I'm
> working in a startup named Tractis in Spain. We have been offering online
> contracts using digital signatures for some years.  We want to allow users
> to use third OPs to login in our site and we want to become an OP too.
>
> Also we want to offer identity services some of them using attribute
> exchange.  We are dealing with attributes being asserted by users and other
> are being certified by third parties (inside assertions,
> X509certificates...). We want to make a difference between attributes being
> asserted and those certified the same way authentication methods have
> different assurance levels PAPE profile.
>
> Please let me paste here the briefing of what I'm talking about.
>
> Disclaimer : the following document is in a very early stage, comments and
> suggestions are highly welcome.
>
> Many thanks for everybody reading :)
>
> Dave
>
> Short briefing for certified-AX profile for OpenId Abstract
>
> Openid AX profile for openid provides a way to exchange attributes between
> relying parties and OP. Those attributes are simple key-value where the keys
> are commonly agreed identifiers and values are encoded strings. This
> approach works fine when dealing with "alegated attributes" like email, name
> ... but a problem arises when we need to trust this information ("certified
> attributes").
>
> There are some services that works fine using alegated identities but some
> specially sensitive services, such as banking, don't. In these sensitive
> scenarios, we need to ensure the quality/trustworthiness of those
> attributes. Making a parallelism with existing open specs we need to apply
> mechanisms analogous to those defined on the PAPE for OP authentication but
> for attribute exchange.
>
> From out point of view, and regarding to this existent needs, it would be
> nice to have those attributes scored using a commonly defined criteria so
> when OP returns a certain set of attributes relying party could trust them
> according to the score that OP gave them.
> Motivations
>
> Openid is moving towards being the de facto standard for authentication on
> the web. There are some other solutions to deal with attributes but it would
> be nice to have a single technology, empowered by the use of their plugins,
> to deal with identity.
> Scenario
>
> Here we'll expose an example of the messages exchanged during certificate
> attributes fetching.
> Fetch Relying party
>
> openid.ns.ax=http://openid.net/srv/ax/1.0 #To be redefined if a new
> release of the protocol is created
>
> openid.ax.mode=fetch_request
>
> openid.ax.type.age=http://axschema.org/birthDate
>
> openid.ax.update_url=http://idconsumer.com/update?transaction_id=a6b5c41
> OpenidProvider
>
> openid.ns.ax=http://openid.net/srv/ax/1.0 openid.ax.mode=fetch_response
>
> openid.ax.type.age=http://axschema.org/birthDate
>
> openid.ax.value.age=23
>
> *openid.ax.score.age=3*
>
> *openid.ax.receipt = #Some kind of receipt certifying the methods used to
> certify the attribute and that could be used for further processes*
>
> openid.ax.update_url=http://idconsumer.com/update?transaction_id=a6b5c41
> Store
>
> In our approach OP deals with attribute certification processes :
> validating certificates, contacting with attribute certification authorities
> ... so there's no sense to allow the store of attributes from others than
> OP.
>
> Store is applied only to non certified attributes, this is score 0.
> What are scores
>
> Scores works in the same way PAPE levels does. They measure the way
> attributes are certified and how the data being certified have been
> collected.
>
> For example: attributes that have been gathered from a *qualified
> certificate* (according to EU Directive on electronic Signatures) that is
> stored inside a SSCD the score will be 4 (means high). On the other hand, a
> name that has been alegated in a web form will have the score 0, means low.
>
> Between 0 and 4 you have all the ways you can certify an attribute from 0
> (no certification) to 4. We made a brief definition of the score concept
> that you could find here (https://www.tractis.com/tractis_score_policy)
> and the mapping to real methods could be found here (
> https://www.tractis.com/tractis_score_mapping<https://www.tractis.com/tractis_score_policy>).
> As we indicate in these documents, we (Tractis) have not invented neither
> the classification nor the score policy but used previous work by the NIST
> and EU.
> Problems to be solved
>
> In Openid attributes are alegated, so you don't have to trust the OP
> because there's nothing to trust on. Dealing with certified attributes
> create a problem : how could I, as a relying party, know that this OP *
> works* fine and if it says "level 4" all criteria to consider were done
> the right way.
>
> Our proposal, in the same way as PAPE, the Relying Party does not need to
> trust the OP. The User is the one that needs to trust the OP. If problems
> arises with certain OP, then relying parties could choose to use some OP and
> exclude others with mechanisms like white/black lists.
>
> Other problem not covered is the format of the receipt (attribute *
> openid.ax.receipt*). Here we can proceed in 2 ways: (1) leaving this
> responsibility to describe the message to the OP or (2) providing an spec
> about it.
>
> Our proposition is: let this field being a signed identifier holding the
> transaction ID for the given fetch request.
>
> There should be a way to connect this ID to the transaction performed on OP
> (attribute fetching transaction) and to the information requested. OP should
> make its best effort to handle as much evidences about the process as
> possible including requested attributes, verified information and returned
> response. But the detail of this evidential information is out of the scope
> of this document.
>
>
>
> --
> David Garcia
> CTO
>
> Tractis - Online contracts you can enforce
> http://www.tractis.com
> --
> Tel: (34) 93 551 96 60 (ext. 260)
>
> Email: david.garcia at tractis.com
> Blog: http://blog.negonation.com
> Twitter: http://twitter.com/tractis
>
> ------------------------------
>
> _______________________________________________
> specs mailing listspecs at openid.nethttp://openid.net/mailman/listinfo/specs
>
>
>

-- 
David Garcia
CTO

Tractis - Online contracts you can enforce
http://www.tractis.com
--
Tel: (34) 93 551 96 60 (ext. 260)

Email: david.garcia at tractis.com
Blog: http://blog.negonation.com
Twitter: http://twitter.com/tractis
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