[Openid-specs-heart] Comment on Section 2.1.3 of Health Relationship Trust Profile for OAuth 2.0
Justin Richer
jricher at mit.edu
Thu Dec 3 21:47:14 UTC 2015
The direct access client is based on deployment experience with the RHEx project and others, where organizations performed bulk data synch transfers between each other. There is an extremely high degree of trust between these organizations, and it’s not just “something form this organization requested it” it’s actually “this specific piece of software requested this specific set of things”. And it’s not on any one user’s authority, it’s a contract that supersedes that. So there’s something that was signed in a dark room someplace that says this transaction can take place within certain parameters, and this is the technology to support that. It’s not up to us to define what those contracts look like, but we can have a say on how the technology is leveraged. Instead of leaving all of these groups to come up with their own “private or internal” way to handle security, we thought it better to give a standards-based mechanism that benefits from much of the rest of the HEART profile updates.
— Justin
> On Dec 3, 2015, at 12:32 PM, Dale Moberg <dale.moberg at orionhealth.com> wrote:
>
>
> Hi, with advance apologies for the holiday-induced delay to our editor.
>
> Section 2.0 introduces three Client Profiles Types in sections 2.1.1 + 2.1.2 and section 2.1.3. I agree with others in the group that the Client Profile types do present “vanilla” profiles for three of the now five specified OAuth2 token grant types (found in RFCs 6749 7521).
> The Full Client and Browser Embedded clients with User delegation are certain to be of value in healthcare (and for the OAuth2-protected security services of UMA and OpenId Connect).
>
> I do, however, have concerns about any inter-organizational uses of the Direct Access Client type in healthcare that I wish to present next. I would advocate deferring implementation of the Direct Access client type until more is agreed upon the intended usage of this pattern. If the only real usage is for “internal” bulk downloads, then organizations are free to accomplish downloads in several ways, including a Direct Access client pattern if they wish. Internal usage can proceed without standards that support interoperability; private or proprietary solutions could suffice. But, if the pattern is implemented for inter-organizational data sharing, the Direct Access client type has several deficiencies.
>
> OAuth2 Full Client types allow a “resource owner” to delegate access to a Client application. While our group often is thinking about important healthcare use cases where resource owners and resource sets map, respectively, to patients and their medical records, nothing requires restricting the pattern in this way. For example, a physician might be a resource owner (and be entitled to both read and delegate access) to all of his patient records to others involved in patient care, by referrals or other processes. What counts semantically in “owner” is that an end user has a userid and password that, in combination with a registered client and its secret is granted access to a set of resources.
>
> So it could be that for a given resource set, there are multiple owners (accessors) able to present credentials and ids and delegate access to a resource set to registered clients presenting their credentials. Or there could be one owner. Bank accounts, facebook pages, google docs – all exhibit their own distinctive requirements for privacy and sharing, and it is at a policy level that these requirements get mulled over and policies get thrashed out.
>
> As a mechanism of requesting and granting or refusing access, the Direct Client type does not mesh well with interorganizational access requests because of some specifics about the healthcare domain.
>
> First, direct access clients are not to be dynamically registered (according to our profile) -- which is very sensible.
>
> So registration must be for a client that “on its own” is trusted with resources. Now suppose that the resource pool (the set of all resource sets) exposes an API that is to support Direct Access Clients. And suppose that the Client is not in the security domain of the resource or authorization servers. Clearly there needs to be considerable trust extended to allow registration of such a client. Because once registered, the access authorization check—no matter what resource is requested-- can only be based on the client_id and the accompanying client_secret. On this basis, a JWT (access token) is issued – containing no more specific or granular information about the requester than its organizational identity; the resource server can check the JWT, is signature and make a call to an introspection service. But the authorization service, once trusted, has said access is permitted, no matter what the resource happened to be, provided the client id and secret are OK.
>
> Now conceivably there are organizations with data to be shared that could leverage organizational identity as a basis for data sharing. A producer of goods might request access to a data base to see all goods purchased by a retailer, and based on which organization is requesting, disallow a producer from seeing how much the retailer had purchased from a competing producer, but still see its own products that had been purchased.But healthcare data sharing is governed by privacy regulations that reflect such challenges as “who’s asking?” “what is their role?" and “what’s your need to know with respect to healthcare provision?” Depending on the answers to these questions, tied to the identity and role(s) of the requesters and their healthcare relevant relationships to the patients/customers, access is granted. The problem with the Direct Access client is that the information needed to check the policy is not provided in the request. A significant side effect would be that no audit trail could be produced to document who got the information and in what capacity and circumstances the information is to be used.
>
> The problem is that the requesting organization has the relevant information about the user(s), role(s) and relationships to the patients but it is not information available in the registration, in the access request, or as an intrinsic part of the client-credentials-only flow used in the Direct Access Client type. The inter-organizational trust/access problem can be succinctly described by noting that we expect the authorization/resource organization to be able to consult the same information about the Direct Access client access request approval identities, roles, and relationships as is used for an internal system request. And the Direct Client pattern lacks specification of ways that the information, or an explanation of how to obtain the information, that is needed for checking that typical healthcare policies apply.
>
> If implementers think that the Direct Access Client support would be important to offer “inside the four walls” -- to use one of our expert’s vivid phrase — then I suppose the profile could be released with that understanding of its intended application range. I would urge the committee to consider very carefully whether they are sufficiently comfortable with the inter-organizational/inter-regional/inter-security-domain security issues to recommend implementation for that context of use.
>
> Dale Moberg
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