Re: [GNAP] Will GNAP support Zero Trust Architecture?

[Fabien Imbault <[e-mail]>]

I was referring to "By my definition, this model has two ASs since both are
processing requests into tokens". If there's no reason to have 2 types of
ASs, that's fine then.
But I'm a bit lost in where we stand with the idea.

Could you recap?

Fabien

Le jeu. 25 mars 2021 à 08:16, Adrian Gropper <[e-mail]> a
écrit :

> There’s no obvious reason to have two types of ASs. Any AS that is
> executing the policies of the RS can look to GNAP like the RS itself. Why
> would GNAP expose that interface to anyone?
>
> Adrian
>
> On Thu, Mar 25, 2021 at 3:11 AM Fabien Imbault <[e-mail]>
> wrote:
>
>> Note : I'm not sure that's a good idea, but having 2 types of ASs is not
>> that easy to grasp.
>>
>> Fabien
>>
>> Le jeu. 25 mars 2021 à 08:07, Fabien Imbault <[e-mail]>
>> a écrit :
>>
>>> The purpose of either handling policies locally or delegating them to
>>> the RO agent.
>>>
>>> Le jeu. 25 mars 2021 à 08:04, Adrian Gropper <[e-mail]> a
>>> écrit :
>>>
>>>> What purpose would be served by GNAP splitting the AS into two
>>>> components?
>>>>
>>>> Adrian
>>>>
>>>> On Thu, Mar 25, 2021 at 2:59 AM Fabien Imbault <
>>>> [e-mail]> wrote:
>>>>
>>>>> Isn't the AS-RO a component of the AS? Same idea as the interact
>>>>> component, it functionnally belongs to the AS role but could be deployed
>>>>> either as a monolith or as a separate component?
>>>>>
>>>>> Fabien
>>>>>
>>>>> Le jeu. 25 mars 2021 à 04:26, Adrian Gropper <[e-mail]>
>>>>> a écrit :
>>>>>
>>>>>> Yes, but I would say it’s not the RO that wants the access token.
>>>>>> It’s the RO that wants the client making the request to get an access
>>>>>> token.
>>>>>>
>>>>>> Adrian
>>>>>>
>>>>>> On Wed, Mar 24, 2021 at 11:22 PM Alan Karp <[e-mail]>
>>>>>> wrote:
>>>>>>
>>>>>>> Adrian Gropper <[e-mail]> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> In this design, the AS is the AS-RS and the agent is the AS-RO. By
>>>>>>>> my definition, this model has two ASs since both are processing requests
>>>>>>>> into tokens. The problem with this is complexity and privacy. The RO may
>>>>>>>> not want to share the request information with the AS-RS.
>>>>>>>>
>>>>>>>
>>>>>>> More precisely, RO has no choice but to present the required
>>>>>>> information to AS-RS if RO wants an access token.  However, RO does not
>>>>>>> want AS-RS to know the policy by which RO delegates tokens.  That's why RO
>>>>>>> uses AS-RO for those delegations.
>>>>>>>
>>>>>>> --------------
>>>>>>> Alan Karp
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Mar 24, 2021 at 7:41 PM Adrian Gropper <
>>>>>>> [e-mail]> wrote:
>>>>>>>
>>>>>>>> Thank you for creating the issue. My definition of AS is
>>>>>>>> independent of AS-RO or AS-RS.
>>>>>>>> https://github.com/ietf-wg-gnap/gnap-core-protocol/issues/223#issuecomment-806280421
>>>>>>>> I also agree with Alan's definition based on delegation. An AS-RS would be
>>>>>>>> a delegate of the RS.
>>>>>>>>
>>>>>>>> Based on that, I see it as obvious that the policy has to be
>>>>>>>> accessible (defined locally?) in order for it to be run as the code that
>>>>>>>> turns a request into an access token.
>>>>>>>>
>>>>>>>> The only other possibility is that the request is packaged by the
>>>>>>>> AS and sent elsewhere (an agent) for evaluation against policy and a
>>>>>>>> proto-token returned. In that case the AS is acting as a proxy and the PDP
>>>>>>>> is elsewhere. I can imagine that an AS-RS would behave this way so that the
>>>>>>>> proto-token could be turned into an access token by the AS-RS. Isn't this
>>>>>>>> what Justin is proposing? In this design, the AS is the AS-RS and the agent
>>>>>>>> is the AS-RO. By my definition, this model has two ASs since both are
>>>>>>>> processing requests into tokens. The problem with this is complexity and
>>>>>>>> privacy. The RO may not want to share the request information with the
>>>>>>>> AS-RS.
>>>>>>>>
>>>>>>>> Adrian
>>>>>>>>
>>>>>>>> On Wed, Mar 24, 2021 at 5:21 PM Fabien Imbault <
>>>>>>>> [e-mail]> wrote:
>>>>>>>>
>>>>>>>>> Isn't that what the AS is supposed to be, only with the caveat
>>>>>>>>> that the policy is defined locally?
>>>>>>>>>
>>>>>>>>> Fabien
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Le mer. 24 mars 2021 à 20:17, Alan Karp <[e-mail]> a
>>>>>>>>> écrit :
>>>>>>>>>
>>>>>>>>>> AS-RO is an AS that RO trusts to delegate RO's access tokens
>>>>>>>>>> according to RO's policies.
>>>>>>>>>>
>>>>>>>>>> --------------
>>>>>>>>>> Alan Karp
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Wed, Mar 24, 2021 at 9:36 AM Fabien Imbault <
>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>
>>>>>>>>>>> Hi Alan and Adrian,
>>>>>>>>>>>
>>>>>>>>>>> I've created issue AS-RO policy delegation (
>>>>>>>>>>> https://github.com/ietf-wg-gnap/gnap-core-protocol/issues/223)
>>>>>>>>>>> to capture your input.
>>>>>>>>>>> A first question that arises: can we give a definition to AS-RO?
>>>>>>>>>>>
>>>>>>>>>>> Thanks
>>>>>>>>>>> Fabien
>>>>>>>>>>>
>>>>>>>>>>> On Tue, Mar 23, 2021 at 4:15 PM Alan Karp <[e-mail]>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Fabien Imbault <[e-mail]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Alan,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes, but in that flow, the token relationship between AS-RS
>>>>>>>>>>>>> and AS-RO is only secure if the tokens issued by AS-RS are
>>>>>>>>>>>>> cryptographically attenuable in the first place.
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Attenuated delegation is a requirement, but that doesn't have
>>>>>>>>>>>> to be done cryptographically.  Token exchange works just fine.  SPKI and
>>>>>>>>>>>> zcap-ld are examples of the crypto approach, and we used token exchange in
>>>>>>>>>>>> the system for HP.
>>>>>>>>>>>>
>>>>>>>>>>>> --------------
>>>>>>>>>>>> Alan Karp
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On Tue, Mar 23, 2021 at 4:12 AM Fabien Imbault <
>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Alan,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes, but in that flow, the token relationship between AS-RS
>>>>>>>>>>>>> and AS-RO is only secure if the tokens issued by AS-RS are
>>>>>>>>>>>>> cryptographically attenuable in the first place.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Fabien
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Mon, Mar 22, 2021 at 9:26 PM Alan Karp <[e-mail]>
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Justin Richer <[e-mail]> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> But with all that in mind, I think the key here is going to
>>>>>>>>>>>>>>> be looking at what the inputs to the AS are, and how those can be defined
>>>>>>>>>>>>>>> in an interoperable way for AS’s that can accept them. I think there’s a
>>>>>>>>>>>>>>> lot of room for innovation and flexibility here that doesn’t break the
>>>>>>>>>>>>>>> trust model or core use cases. If I have an AS-RS set that won’t accept my
>>>>>>>>>>>>>>> favorite flavor of policy engine inputs, then I can decide not to use that
>>>>>>>>>>>>>>> one. But this is a very different question than saying the RS itself needs
>>>>>>>>>>>>>>> to accept my own AS — and we can’t keep conflating these two models.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I agree.  The point of having an AS-RO is to allow RO to
>>>>>>>>>>>>>> specify a policy for which of RO's access tokens should be delegated under
>>>>>>>>>>>>>> what conditions.  AS-RS should not need to understand those policies.  The
>>>>>>>>>>>>>> flow would be
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>    - RO contacts AS-RS and gets one or more access tokens.
>>>>>>>>>>>>>>    - RO delegates one or more of those tokens, potentially
>>>>>>>>>>>>>>    sub-scoped, to AS-RO.
>>>>>>>>>>>>>>    - A different user contacts AS-RO to get a potentially
>>>>>>>>>>>>>>    sub-scoped access token from AS-RO.
>>>>>>>>>>>>>>    - That user presents the access token delegated by AS-RO
>>>>>>>>>>>>>>    when invoking the resource.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> AS-RS only needs to verify that the delegation chain is
>>>>>>>>>>>>>> legitimate, e.g., no increase in scope, and that it grants permission for
>>>>>>>>>>>>>> the request being made.  AS-RS does not need to understand the policy
>>>>>>>>>>>>>> behind granting the delegation by AS-RO.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --------------
>>>>>>>>>>>>>> Alan Karp
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Mon, Mar 22, 2021 at 11:40 AM Justin Richer <
>>>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Adrian,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I think this shows the problem with the terminology as it’s
>>>>>>>>>>>>>>> been applied in this conversation, which I’ve tried to shine light on
>>>>>>>>>>>>>>> before. What you and others are calling the “RS” is really the “AS and RS
>>>>>>>>>>>>>>> working together” — everything to the right of the line. When Denis had
>>>>>>>>>>>>>>> brought up “eliminating the AS” in another thread, what he’d really done is
>>>>>>>>>>>>>>> labeled everything to the right of the line as the “RS”. Of course, the
>>>>>>>>>>>>>>> irony here is that everything to the right of the line used all be called
>>>>>>>>>>>>>>> the “AS” or simply “server” in the OAuth 1 days. As you say below, I don’t
>>>>>>>>>>>>>>> want the client to have visibility on what happens on that side.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Note well: The Google+ logo labeled “IdP” in the diagram is
>>>>>>>>>>>>>>> not the AS, as far as GNAP is concerned. It does not issue an access token
>>>>>>>>>>>>>>> that the RS will accept. The elements to the left of the line could be a
>>>>>>>>>>>>>>> lot of things, but they are NOT the AS — by definition. The client lives
>>>>>>>>>>>>>>> over on the left, but so do any external inputs to the AS. These could be
>>>>>>>>>>>>>>> policy inputs on behalf of the RO, they could be presentation artifacts,
>>>>>>>>>>>>>>> they could be federated logins, they could be the output of policy
>>>>>>>>>>>>>>> decisions. How the AS comes to trust those things is up to the AS’s
>>>>>>>>>>>>>>> implementation. It’s something we can talk about, but ultimately GNAP won’t
>>>>>>>>>>>>>>> be in any position to dictate because in practice some AS’s are simply
>>>>>>>>>>>>>>> going to internalize all policies and we will never successfully force
>>>>>>>>>>>>>>> those open.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> But with all that in mind, I think the key here is going to
>>>>>>>>>>>>>>> be looking at what the inputs to the AS are, and how those can be defined
>>>>>>>>>>>>>>> in an interoperable way for AS’s that can accept them. I think there’s a
>>>>>>>>>>>>>>> lot of room for innovation and flexibility here that doesn’t break the
>>>>>>>>>>>>>>> trust model or core use cases. If I have an AS-RS set that won’t accept my
>>>>>>>>>>>>>>> favorite flavor of policy engine inputs, then I can decide not to use that
>>>>>>>>>>>>>>> one. But this is a very different question than saying the RS itself needs
>>>>>>>>>>>>>>> to accept my own AS — and we can’t keep conflating these two models.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> So to me, GNAP can support a Zero Trust Architecture by
>>>>>>>>>>>>>>> LEVERAGING the AS, not by subsuming or eliminating it. It is in fact the
>>>>>>>>>>>>>>> AS, not the client and not the RS, that will request and consume the
>>>>>>>>>>>>>>> results of a privacy-preserving zero-trust policy query thing. Anything
>>>>>>>>>>>>>>> that happens downstream from that is of little concern to the zero-trust
>>>>>>>>>>>>>>> components because, as you point out, it’s on the “other side” of the line.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I think we got this basic component model pretty right in
>>>>>>>>>>>>>>> OAuth: the AS and RS and client working together. Where OAuth misses the
>>>>>>>>>>>>>>> mark is the assumption that the user has to log in to the AS through a
>>>>>>>>>>>>>>> webpage and interact directly, thereby proving they’re the RO. It’s this
>>>>>>>>>>>>>>> latter space where I think we can both push innovation and also address the
>>>>>>>>>>>>>>> important and compelling use cases like the ones you’re bringing.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>  — Justin
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Mar 22, 2021, at 2:14 PM, Adrian Gropper <
>>>>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I'm sorry, Justin. As a Resource Owner, I look at the RS
>>>>>>>>>>>>>>> trust boundary (the dotted line in the diagram) as being the RS. I don't
>>>>>>>>>>>>>>> expect any visibility into what's going on on the right.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> My problem with the framing you propose is that requests are
>>>>>>>>>>>>>>> going to the RS (or the AS-RS) and I don't want to share my policies with
>>>>>>>>>>>>>>> the AS-RS. I want to keep the RS and AS-RS as ignorant as possible.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Adrian
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Mon, Mar 22, 2021 at 1:48 PM Justin Richer <
>>>>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Adrian,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> What you’re discussing below, in terms of logging in to a
>>>>>>>>>>>>>>>> site, is not approaching the RS. You are in fact approaching the client,
>>>>>>>>>>>>>>>> and identifying both the AS and RS to the client. The client is a client *of
>>>>>>>>>>>>>>>> your identity* in this model, and the RS is part of the
>>>>>>>>>>>>>>>> identity provider. It’s really important that we don’t conflate the RS and
>>>>>>>>>>>>>>>> client in this way as it leads to a lot of confusion downstream and a lot
>>>>>>>>>>>>>>>> of broken trust boundaries.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> With that model in mind, approaching the “RS" and providing
>>>>>>>>>>>>>>>> it your identity is really just a case of the “federated login to AS”
>>>>>>>>>>>>>>>> pattern that we discussed on the WG call. The user here approaches an RS,
>>>>>>>>>>>>>>>> which has its own AS. To share things from this RS, the RO has to
>>>>>>>>>>>>>>>> authenticate to the RS’s AS. This particular AS allows the RO to do so
>>>>>>>>>>>>>>>> using an external identity — in which case, the AS is now a “client” of a
>>>>>>>>>>>>>>>> separate, disconnected (but layered) delegation. The ultimate client that
>>>>>>>>>>>>>>>> eventually calls the RS down the way may or may not know about these
>>>>>>>>>>>>>>>> layers.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> <PastedGraphic-1.png>
>>>>>>>>>>>>>>>> This same AS, which is closely tied to the RS and trusted
>>>>>>>>>>>>>>>> by the RS, might also take in FIDO credentials, or DIDs, or any number of
>>>>>>>>>>>>>>>> other proof mechanisms. The output of this is an access token the RS
>>>>>>>>>>>>>>>> trusts, but the input is up to the AS. The RS is not what you’re logging in
>>>>>>>>>>>>>>>> to.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>  — Justin
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Mar 22, 2021, at 1:28 PM, Adrian Gropper <
>>>>>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I too am in favor of avoiding consolidation and
>>>>>>>>>>>>>>>> correlation. Right now, when I approach a service provider (RS) for the
>>>>>>>>>>>>>>>> first time, I'm offered the opportunity to identify my persona as: email,
>>>>>>>>>>>>>>>> sign-in with Google, Facebook, or Apple. I know there are people who try to
>>>>>>>>>>>>>>>> create one-off email addresses but that is mostly a waste of time.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> So, along come FIDO2 and DID wallets to the rescue. Now, in
>>>>>>>>>>>>>>>> theory, I have a way to start out my RS relationship pseudonymously.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> When I want my resource to be discovered or shared I will
>>>>>>>>>>>>>>>> post that RS URL including my pseudonym. If I then want to introduce a
>>>>>>>>>>>>>>>> mediator in front of my AS or messaging service endpoint, I have that
>>>>>>>>>>>>>>>> option. If I want to keep requests away from the mediator, I would publish
>>>>>>>>>>>>>>>> an encryption key along with my pseudonym.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> - Adrian
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Mon, Mar 22, 2021 at 9:55 AM Justin Richer <
>>>>>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On Mar 21, 2021, at 1:18 PM, Benjamin Kaduk <[e-mail]>
>>>>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > On Sat, Mar 20, 2021 at 01:07:42AM -0400, Adrian Gropper
>>>>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>>>> >> @Alan Karp <[e-mail]> shared a talk about
>>>>>>>>>>>>>>>>> the Principle Of Least
>>>>>>>>>>>>>>>>> >> Authority (POLA) in a recent comment
>>>>>>>>>>>>>>>>> >>
>>>>>>>>>>>>>>>>> https://github.com/ietf-wg-gnap/gnap-core-protocol/issues/145#issuecomment-803099693
>>>>>>>>>>>>>>>>> >> I recommend it.
>>>>>>>>>>>>>>>>> >>
>>>>>>>>>>>>>>>>> >> We might expect a protocol with authorization in the
>>>>>>>>>>>>>>>>> title to use authority
>>>>>>>>>>>>>>>>> >> as a core principle. I advocate for a GNAP design that
>>>>>>>>>>>>>>>>> maximizes the power
>>>>>>>>>>>>>>>>> >> of the RO, to be seen as a human rights issue when the
>>>>>>>>>>>>>>>>> RO is a human. This
>>>>>>>>>>>>>>>>> >> causes me to ask how to combine better security with
>>>>>>>>>>>>>>>>> better human rights in
>>>>>>>>>>>>>>>>> >> GNAP.
>>>>>>>>>>>>>>>>> >>
>>>>>>>>>>>>>>>>> >> Who should have the least authority in the GNAP design?
>>>>>>>>>>>>>>>>> >>
>>>>>>>>>>>>>>>>> >> The AS derives authority as a delegate of the RO. If we
>>>>>>>>>>>>>>>>> ask the RO to
>>>>>>>>>>>>>>>>> >> partition limited authority across dozens of different
>>>>>>>>>>>>>>>>> ASs by domain and
>>>>>>>>>>>>>>>>> >> function, then we are not using technology to empower
>>>>>>>>>>>>>>>>> the individual.
>>>>>>>>>>>>>>>>> >> Probably the opposite, as we introduce consent fatigue
>>>>>>>>>>>>>>>>> and burden normal
>>>>>>>>>>>>>>>>> >> people to partition their lives into non-overlapping
>>>>>>>>>>>>>>>>> domains.
>>>>>>>>>>>>>>>>> >>
>>>>>>>>>>>>>>>>> >> My experience says we should aim for one AS per persona
>>>>>>>>>>>>>>>>> because that maps
>>>>>>>>>>>>>>>>> >> into the way we manage our public and private
>>>>>>>>>>>>>>>>> identities. POLA would then
>>>>>>>>>>>>>>>>> >> teach care in keeping ASs and RSs related to work /
>>>>>>>>>>>>>>>>> public separate from
>>>>>>>>>>>>>>>>> >> ASs and RSs related to private life so that a policy
>>>>>>>>>>>>>>>>> vulnerability in our
>>>>>>>>>>>>>>>>> >> delegation to an AS would have the least likelihood of
>>>>>>>>>>>>>>>>> harm.
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > Thinking about how least authority/least privilege would
>>>>>>>>>>>>>>>>> apply to GNAP
>>>>>>>>>>>>>>>>> > seems like a useful exercise.  I do want to point out
>>>>>>>>>>>>>>>>> some potential
>>>>>>>>>>>>>>>>> > pitfalls with one-AS-per-persona that we can also be
>>>>>>>>>>>>>>>>> aware of.  If
>>>>>>>>>>>>>>>>> > one-AS-per-persona becomes one-persona-per-AS as well,
>>>>>>>>>>>>>>>>> then the AS's
>>>>>>>>>>>>>>>>> > identity in effect also serves as a persona identity and
>>>>>>>>>>>>>>>>> there are privacy
>>>>>>>>>>>>>>>>> > considerations to that.  If, on the other hand, the
>>>>>>>>>>>>>>>>> > multiple-personas-per-AS (presumably corresponding to
>>>>>>>>>>>>>>>>> multiple humans)
>>>>>>>>>>>>>>>>> > route is taken, we should consider whether that would
>>>>>>>>>>>>>>>>> lead to various
>>>>>>>>>>>>>>>>> > (e.g., market) forces driving consolidation to just a
>>>>>>>>>>>>>>>>> handful of
>>>>>>>>>>>>>>>>> > super-popular AS services.  That topic is a current
>>>>>>>>>>>>>>>>> matter of concern to
>>>>>>>>>>>>>>>>> > some IETF participants.
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Hi Ben, big +1 to this. This is something that we
>>>>>>>>>>>>>>>>> discussed ages ago in the UMA working group, and it’s one of the biggest
>>>>>>>>>>>>>>>>> problems with the personal AS (and personal data store) model. This kind of
>>>>>>>>>>>>>>>>> thing makes RS-first trust models really difficult in practice.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> As a strawman, let’s say that I’ve got software that wants
>>>>>>>>>>>>>>>>> to access my medical information. It calls an RS and requests access, but
>>>>>>>>>>>>>>>>> it hasn’t been granted anything yet. Now I as the RO have set up the RS so
>>>>>>>>>>>>>>>>> that it talks to my personal AS, that only I use. In addition to the RS
>>>>>>>>>>>>>>>>> having to be able to figure out which medical records are being requested
>>>>>>>>>>>>>>>>> from the context of the unauthenticated request (which means it needs
>>>>>>>>>>>>>>>>> identifiers in the URL or something similar for the RS to be able to tell,
>>>>>>>>>>>>>>>>> assuming that it protects data for more than one person). So this client
>>>>>>>>>>>>>>>>> software doesn’t know who I am and doesn’t know my medical record
>>>>>>>>>>>>>>>>> information, makes a completely unauthorized request to the RS, and the RS
>>>>>>>>>>>>>>>>> says “Go to Justin’s personal AS to get a token”. The client can now make a
>>>>>>>>>>>>>>>>> direct correlation between the data that’s being protected at the RS and
>>>>>>>>>>>>>>>>> the person running the AS that protects it. Importantly, this client makes
>>>>>>>>>>>>>>>>> this call with no prior relationship to the RS and no really auditable way
>>>>>>>>>>>>>>>>> to track it down after the fact. This is a design feature in the good case,
>>>>>>>>>>>>>>>>> and terrifying in the bad case.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> If the RS instead says “welcome to Medicine Doctor RS,
>>>>>>>>>>>>>>>>> please talk to the Medicine Doctor AS to get access”, we haven’t exposed
>>>>>>>>>>>>>>>>> anything at all. And from the perspective of both the patient and the RS,
>>>>>>>>>>>>>>>>> this is more privacy-preserving, and it’s really the least surprising
>>>>>>>>>>>>>>>>> option. Once the client gets to the AS, it can start a negotiation of
>>>>>>>>>>>>>>>>> figuring out who the RO is for the information being accessed.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On top of this, the usability expectations of people
>>>>>>>>>>>>>>>>> managing their own AS, or set of AS’s for multiple personas to keep things
>>>>>>>>>>>>>>>>> separate, is a huge burden. Even in the tech community, I know people who
>>>>>>>>>>>>>>>>> can’t reliably manage more than one email address for different purposes. I
>>>>>>>>>>>>>>>>> wouldn’t expect my partner to do that — they have trouble enough balancing
>>>>>>>>>>>>>>>>> all the logins and sessions required for different kids remote schooling, I
>>>>>>>>>>>>>>>>> couldn’t imagine them having to understand all the requirements for
>>>>>>>>>>>>>>>>> managing multiple authorization servers and associated policies. I also
>>>>>>>>>>>>>>>>> don’t expect any person to “manage keys” — I’ve been on the internet for
>>>>>>>>>>>>>>>>> decades and I can barely keep tabs on my GPG keys, and only use them when I
>>>>>>>>>>>>>>>>> am forced to. This is exactly the kind of “market pressure” that I think
>>>>>>>>>>>>>>>>> Ben mentions above, people will just want to outsource that to someone
>>>>>>>>>>>>>>>>> else, and the reality will be a few popular providers.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> In which case, we could end up doing a ton of work to
>>>>>>>>>>>>>>>>> allow an RS choice only to end up with a world where the RS ends up making
>>>>>>>>>>>>>>>>> a limited choice anyway. We see how that plays out with OpenID Connect —
>>>>>>>>>>>>>>>>> RP’s could allow arbitrary IdPs but they choose Google because it works and
>>>>>>>>>>>>>>>>> that’s where the users are. (And that’s not to say anything of the
>>>>>>>>>>>>>>>>> proprietary OIDC-like protocols, but that’s another discussion).
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> For further reading on these topics, I recommend both “Why
>>>>>>>>>>>>>>>>> Johnny Can’t Encrypt” and “Why CSCW Systems Fail”.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> So what does this have to do with GNAP? I think we can be
>>>>>>>>>>>>>>>>> clear-eyed on what kinds of expectations we have for the participants. If
>>>>>>>>>>>>>>>>> we expect users (RO’s) to have to set up the AS-RS relationship, or expect
>>>>>>>>>>>>>>>>> them to carry their AS, or manage their personal keys — I think we’ve lost
>>>>>>>>>>>>>>>>> the battle for relevance.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  — Justin
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
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