[OpenID] Too many providers... and here's one reason

[Andrew Arnott]

You're affirmative action example is well taken.  Obviously if an OP is the
best solution we should go with it.  But just imagine what all these spoons
of sugar are going to do to me...
Suppose I'm a member of 15 organizations (that's conservative) between my
professional, social, personal lives.  Some RP could be interested in
providing specialized services if I am a member of Org XYZ.  Another RP may
offer premium services if I am a member of Org ABC.

Now if every org I am a member of became an OP, then my identity XRDS file
now has at least 15 providers listed.  Powerful, perhaps.  Dangerous: yes!!!
 If OpenID's weakness already was that if an OP was compromised then all
Identifiers that allow that OP's assertions are now compromised, then that
weakness is proportional to the number of OPs that are listed in my XRDS
file.  I for one do NOT want 15 Providers listed in my XRDS file.  There was
a time I thought more was better, and to date I have some 5-6 OPs listed,
but I've considered narrowing that down to just 2-3 to decrease my risk
surface area.

Using OAuth as a post-authentication step of confirming membership is an
interesting idea and should work.  In the end, whether we use OpenID or
OAuth, it seems we're mixing authentication and membership, or authorization
and membership, in order to just get membership.  Too bad there's not just a
way to get "membership".

Yes, InfoCard managed cards solve this problem, although not as implicitly
as I'd like.  I'm hoping OpenID can have a solution of its own.

On Mon, Sep 15, 2008 at 5:12 PM, Eran Hammer-Lahav <eran at hueniverse.com>wrote:

>  This is like applying affirmative action to cooking. "This cake calls for
> two spoons of sugar but we don't have enough people using lard in cakes, so
> I am going to use it instead..."
>
> Looks like they want to use OpenID as an assertion verification protocol,
> allowing them to confirm that a given user is in fact a member of their
> organization. If all they want to do is assert the claim, they can use both
> OAuth and OpenID, each with a different set of extra features. If they use
> OpenID, a side-effect of this will turn them into an Identity Provider, but
> if this is not their intention, they should not use that identifier
> internally, but instead accept OpenID.
>
> In other words, they should be an OP for assertion verification, and RP for
> site login.
>
> EHL
>
>
>
> On 9/15/08 4:45 PM, "Andrew Arnott" <andrewarnott at gmail.com> wrote:
>
> I just spoke with an organization that wants to become a Provider so that
> other RP web sites can specifically tell if the logging in user is a member
> of this organization by whether their OpenID Identifier was asserted by that
> org's OP.
>
> Ideally, I'd like this org to choose to be an RP instead of an OP because
> there are already too many OPs out there and not enough RPs, IMO.
>
> How can an RP accept an OpenID Identifier from arbitrary OPs, but at each
> login determine whether the Identifier represents a user who belongs to a
> particular Organization?  Basically the Organization needs to send an
> assertion about the Identifier's membership, but only be willing to do so if
> that identifier is confirmed as having logged in successfully to that RP.
>  This would be easy to do if that Org was an OP, but I'm trying to reduce
> the # of reasons to be an OP.
>
>
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