[Openid-specs-ab] Identifiers and discovery.

Wed Apr 13 13:59:38 UTC 2011

I think 2 & 3 are more properly attributes than identifiers.

Earlier I brought up the idea of having user discovery information as a protected resource.

That is not to say that there is not a need for some unauthenticated discovery, though for privacy reasons we probably want to minimize that.

openID 2 required that the claimed ID is discoverable as part of the security process. (looking up users other services was never used by anyone)

We don't have that security requirement any more, because it has been subsumed by using the access token at the user info endpoint.

We have other identifiers for discovery that can be returned in the user info endpoint.  

What that lacks is being able to prove that those reassignable discovery endpoints belong to you.  Though if they contain only self asserted information that is probably not an issue.

If the user is authenticated then their user info or other protected endpoint is the best place to get information.

If they are not authenticated then probably a reassignable identifier that the user can remember is the better option.

John B.

On 2011-04-13, at 4:53 AM, <Axel.Nennker at telekom.de> wrote:

> You say:
> 1) Persistent Identifier (in the scope of the OP), never reassigned
> lasjkflasdflsajfljal02384ß20183lskadjfölsafj
> 
> 2) UI Identifier
> Fullname: Axel Nennker
> Profilepicref: https://www.google.com/s2/photos/public/AIbEiAIAAABECOzLpfXm2dn7pAEiC3ZjYXJkX3Bob3RvKihiODRmYjAxMDU0ZjdhYmVmMzI4MGZmN2I0ZWI4NWY1OThlZjQ3MmMxMAH08_TJz4ElY-WIBPBE1pmNuOStyQ (is this persistent?)
> 
> 3) Contact Identifier
> Work: axel.nennker at telekom.de
> Private: ignisvulpis at gmail.com
> Personal: axel at nennker.de
> Tel: +491702275312
> 
> Right?
> 
> Is https://www.google.com/profiles/ignisvulpis in category 1? Never reassigned?
> 
>> -----Original Message-----
>> From: Breno de Medeiros [mailto:breno at google.com] 
>> Sent: Wednesday, April 13, 2011 10:38 AM
>> To: Nennker, Axel
>> Cc: openid-specs-ab at lists.openid.net
>> Subject: Re: [Openid-specs-ab] Identifiers and discovery.
>> 
>> On Wed, Apr 13, 2011 at 01:15,  <Axel.Nennker at telekom.de> wrote:
>>> 
>>> Similar for me. I gave up on trying to attend because 4pm 
>> PT is 1am here, so I went to sleep at 23:30 and could have 
>> made it for midnight.
>>> Anyway.
>>> 
>>> Regarding identifiers: Some people expect that the openid 
>> is "fancy" and easy to distiguish.
>>> Example: @t is much cooler than @AxelNennker or pt at fb.com 
>> is cooler than user4711 at facebook.com or
>>> https://me.google.com/AxelNennker is cooler than 
>> https://me.google.com/users/lasjkflasdflsajfljal02384ß20183lsk
>> adjfölsafj
>>> 
>>> The uglier ones achieve the goal of beeing not reassigned 
>> much easier than the prettier ones.
>>> 
>>> Display Names are an related issue: I guess that there are 
>> more than one "Mike Jones" in Microsoft possibly even more 
>> than one "Michael B. Jones". Each has a unique identifier 
>> which might be reassigned (after a grace period) to a new 
>> Michael B. Jones.
>>> 
>>> This is not only a technical problem. People want the 
>> pretty identifiers.
>> 
>> It is a technical problem. If we label the identifiers in the 
>> protocol as:
>> 
>> - Identifier 1: This is persistent. Use as index in your DB. E.g: a
>> numeric value.
>> - Identifier 2: This is what the user wants you to represent him as.
>> E.g: a name, photo, business card, etc.
>> - Identifier 3: This is what the user thinks you can use to find who
>> he is. E.g.: an email address
>> 
>>> The best we can achieve, I think, is that users never see 
>> the unique, never reassigned (, maybe global) identifiers.
>>> And that the UI for the display names is powerfull enough 
>> to help me to find the Mike Jones I want to reach.
>>> 
>>> Example: Consider a blog post with comments by openid 
>> users. The blog received a sreg fullname and the 
>> openid.claimed_id and openid.identity.
>>> Now it renders the fullname on the html page giving us 
>> comment by several Mike Jones. The "social" rendering would 
>> allow my user agent to render the comments from my friend 
>> list other than comments from people I don't know.
>>> 
>>> Ok, this moves away from pure protocol issues and issuer 
>> policy to OC best practices and UI issues.
>>> I am not sure how the openid abc wg "protocol" group can 
>> solve this non technical problems.
>>> 
>> 
>> No, that's the mistake OpenID2 fell into. We should have different
>> identifiers for different purposes so that it's foolproof how to deal
>> with this.
>> 
>> My proposal is that the identifier used in auth is number 1. You know
>> you can't use to do anything presentational with it.
>> Identifier #2 is the easiest: we return attributes at the user info
>> endpoint that can be used to personalize the user experience.
>> Identifier #3 is missing from the current drafts. I can see two
>> sensible approaches:
>> 
>> - Define a discovery protocol that starts by going to the issuer and
>> asking what it knows about the asserted user_id. The advantage of
>> doing this is that we can support both public and protected (meaning
>> that user needs to consent) discovery with the same set of techniques.
>> 
>> - Use the email or profile URL (both which will be returned as user
>> attributes) as discovery starting points. This has some advantages in
>> that we may be able to re-use some existing ideas and techniques.
>> 
>> Again, what we don't want is an identifier that does all 
>> three jobs poorly.
>> 
>>> -Axel
>>> 
>>>> -----Original Message-----
>>>> From: openid-specs-ab-bounces at lists.openid.net
>>>> [mailto:openid-specs-ab-bounces at lists.openid.net] On Behalf
>>>> Of Breno de Medeiros
>>>> Sent: Tuesday, April 12, 2011 6:18 PM
>>>> To: openid-specs-ab at lists.openid.net
>>>> Subject: [Openid-specs-ab] Identifiers and discovery.
>>>> 
>>>> I hope Nat's well.
>>>> 
>>>> I was in a meeting at 3:00pm (that I scheduled after 
>> JBradley asserted
>>>> the conference call would take place as usual at 4pm). 
>> When I joined,
>>>> Mike Jones and Nat were dropping off the call.
>>>> 
>>>> That left JBradley and I on the call. We had a discussion on
>>>> identifiers and discovery.
>>>> 
>>>> I would like to continue this conversation via email, as it's
>>>> an important one.
>>>> 
>>>> 
>>>> Currently, Google's proposal on identifiers is:
>>>> 
>>>> - Identifiers are unique to the user and non-reassignable 
>> within the
>>>> scope of the issuer. However, they need not be globally unique.
>>>> 
>>>> - Id_tokens attest to the issuer and therefore provide a 
>> statement of
>>>> the globally unique (issuer_id, user_id) pair. If the signature is
>>>> based on PK, these tokens are also universally verifiable and fully
>>>> portable.
>>>> 
>>>> Looking forward to an interesting discussion,
>>>> 
>>>> --
>>>> --Breno
>>>> _______________________________________________
>>>> Openid-specs-ab mailing list
>>>> Openid-specs-ab at lists.openid.net
>>>> http://lists.openid.net/mailman/listinfo/openid-specs-ab
>>>> 
>>> 
>> 
>> 
>> 
>> -- 
>> --Breno
>> 
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