[OpenID] About Facebook, MySpace and OpenID

John Bradley john.bradley at wingaa.com
Sun Apr 5 04:12:01 UTC 2009


If you ask google for a required AX attribute, email as an example and  
the user declines to send it to you Google sends back a negative  
assertion and you never find out the users claimed_id.

In my tests of Google a user has the option of continuing with the  
login and returning the required AX attributes or canceling and not  
logging in.

If the user cancels the RP would need to send a second checkid_setup  
without the required AX attribute request.  Log the user in and then  
perform some additional separate openID step to get the AX attributes.

For a RP to deal properly with a Google openID they should separate  
the Auth from the AX exchange otherwise if the the user declines  
sending the attributes to the RP they also decline sending the  

Technically they are not violating the AX spec but to be useful the  
flow needs to be different from what RPs are doing with other OPs.

That is why I am hinting at the need for some higher-level definition/ 
standard for the UX flows.

John Bradley

On 4-Apr-09, at 8:29 PM, Peter Williams wrote:

> If I’m an RP taking authenticated comments from a google subscriber  
> for the first time and the user denies the release of the optional  
> email attribute, is there any way for the user to release it the  
> next time s/he attempts to post a comment?
> i.e. depending on the nature of the  comment or the thread, the user  
> may wish  to release or not release the email identifier (to signal  
> that followup email dialog is available, or to receive events that  
> the comments received followup). Lets assume that the site  
> processing the comments does not maintain an account for the  
> commenting user.
> From: general-bounces at openid.net [mailto:general-bounces at openid.net]  
> On Behalf Of Breno de Medeiros
> Sent: Saturday, April 04, 2009 6:38 PM
> To: Deron Meranda
> Cc: general; John Bradley
> Subject: Re: [OpenID] About Facebook, MySpace and OpenID
> It is not true that you need to request all your attributes for the  
> Google OP or else you will be locked out. If you add a request for a  
> new attribute we will prompt the user to authorize and then send  
> it.  That also happens if the value of the attribute changed since  
> the user approved (re-prompt and send).
> On Apr 3, 2009 9:35 PM, "Deron Meranda" <deron.meranda at gmail.com>  
> wrote:
> On Fri, Apr 3, 2009 at 11:08 PM, Andrew Arnott  
> <andrewarnott at gmail.com> wrote:
> > ... All the RPs are upgrading their email requests to required
> > so that they work with Google.  Apparently they really wanted  
> email and they > were getting it unt...
> Maybe its useful to think about attributes other than email to see
> where "optional" perhaps makes more sense.
> Consider a possible Time Zone attribute (yes SReg has this).  This  
> is a case
> where it is easier to see what an RP might mean by "optional" --  
> that if the
> OP can provide it it wants it; but if not, the RP still wants the  
> authentication
> to proceed and not to fail, because it can deal easily enough with not
> getting the time zone.
> It could also be argued that the OP *should* ask the user which  
> optional
> attributes it wants to give.  You might not think time zone is  
> important
> enough to ask the user for permission; unless perhaps your time zone
> happened to be America/Havana for example and you didn't want this
> RP to know you're in Cuba.
> I can see Google's perspective on this; and it is a combination of
> trying to make a simple UI for non-technical users (which we all
> agree is something OpenID desperately needs), as well as the
> spec being somewhat silent on what its expectations are for the
> OP and RP.
> However, at this point, with Google's current interpretation, there is
> effectively no utility in having optional attributes.  The  
> distinction is
> made meaningless.  And since we don't want RP's to special-case per
> OP; then effectively, in practice today anyway, it is pointless for
> OpenID AX to pretend there is an optional/required dimension.
> Now one can argue that Google is right and the spec was trying to
> make two categories when only one made sense; or that Google is
> wrong and OPs should definitely treat optional attributes differently
> than required ones.  I'm not sure which is correct; but I do think
> that the spec should be made very clear one way or the other.
> Because if the behavior is left up to the OP, as Google has done, then
> the spec is made pointless in practice and its all just unnecessary
> noise words.
> I would say, another thing that Google does that may play into all
> this is that they don't always send AX attributes back at all.  If the
> RP and OP have communicated before concerning a certain
> identity; then the RP may actually get no attributes whatsoever
> on subsequent interactions (Google assumes that the RP will
> remember these attributes the first time, which means that in
> practice the RP will be forced to remember these attributes).
> This also coerces the RP to try to request ALL the attributes it  
> thinks
> it might ever need the very first time it interacts with Google.   
> And since
> it also using is directed identity (where the RP doesn't know the  
> identity
> before hand), this effectively means that the RP is going to have to
> request all the possible AX attributes it might ever desire for any  
> user,
> effectively as a *requred* attribute, on every single request!   
> Because if
> it guesses wrong and decides not to ask for a particular attribute  
> even
> once, it may then be locked out of ever getting that attribute in  
> the future.
> This makes it very hard to implement an RP.  Either it asks for too
> many attributes, and the authentication fails because the user  
> doesn''t
> want to return ALL of them (or Google doesn't support a hypothetical
> Time Zone AX attribute and treats optional as-if required so it  
> fails).
> --  Or on the other hand the RP doesn't ask for enough attributes; but
> then has to live with never being able to ask for them in the future  
> when
> it later decides it does want to know them.
> And the directed identity on top of this means the RP has to make this
> difficult choice just once per OP, rather than a finer grained per  
> identity.
> I think this existing behavior, although defensible from Google's
> perspective; pretty much renders a good portion of the AX spec
> completely useless.
> Either an RP is never going to use AX at all because it doesn't want
> to risk causing an authentication to fail; or an RP is always going to
> request as many attributes as possible all as required (even if it
> doesn't need them right now), because it doesn't want to miss out on
> it's one chance to get that information the first time.
> --
> Deron Meranda

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