[keycloak-dev] Pairwise Subject Identifier

Stian Thorgersen sthorger at redhat.com
Mon Aug 22 04:42:24 EDT 2016


IMO it's sufficient to document the algorithm to create the sub, which
should make it clear that the origin in the redirect uri will affect the
sub. One client could also have multiple redirect uris with different
origins so could get different sub's generated depending on the redirect
uri used.

On 22 August 2016 at 09:58, Martin Hardselius <martin.hardselius at gmail.com>
wrote:

> Sounds fair enough.
>
> What about the case where you don't provide a sector_identifier_uri, set
> up a single redirect uri on myhost and then later go on to change that
> redirect uri to something on myotherhost? That would change the
> sector_identifier and subsequently all the user subs. Do we protect against
> such "mistakes" or do we warn people (in the docs and/or admin gui) that
> it's not a good idea to do that?
>
> On Mon, 22 Aug 2016 at 09:38 Stian Thorgersen <sthorger at redhat.com> wrote:
>
>> We need to follow the spec and verify that sector_identifier_uri points
>> to a URL that contains the corresponding URIs. As an enhancement we could
>> support wildcards in the JSON returned by sector_identifier_uri. For
>> example if it returns:
>>
>> [ https://www.mydomain.com/*, https://www.myotherdomain.com/* ]
>>
>> A client with the redirect uri 'https://www.myotherdomain.com/myapp'
>> would work
>>
>> On 18 August 2016 at 15:09, Martin Hardselius <
>> martin.hardselius at gmail.com> wrote:
>>
>>> Speaking of subject_identifier_uri
>>>
>>> From the spec:
>>>
>>> "When a sector_identifier_uri is provided, the host component of that
>>> URL is used as the Sector Identifier for the pairwise identifier
>>> calculation. The value of the sector_identifier_uri MUST be a URL using
>>> the https scheme that points to a JSON file containing an array of
>>> redirect_uri values. The values of the registered redirect_uris MUST be
>>> included in the elements of the array."
>>>
>>> What's your stance on sanity/health checking the sector_identifier_uri?
>>> URI validation is one thing, but should we also make a request to the uri
>>> in order to validate the response?
>>>
>>> The spec also mentions that the sector_identifier_uri isn't strictly
>>> required if a client has all it's redirect_uris under the same domain. How
>>> do we deal with changes to clients if the sector_identifier_uri isn't
>>> required for enabling pairwise subs?
>>>
>>> Example:
>>>
>>> I create a client, enabling pairwise subs. Valid redirect_uris are [
>>> https://www.mydomain.com/* ]. The sector_identifier would be mydomain.
>>>
>>> Later on, I update the redirect_uris to [ https://www.mydomain.com/*,
>>> https://www.myotherdomain.com/* ] Do we
>>>
>>> * keep the old sector_identifier, or
>>> * reject the update, or
>>> * allow the update if a valid subject_identifier_uri is provided at
>>> mydomain, or
>>> * just allow it and let the client devs deal with the consequences, or
>>> * take some other path you can think of ?
>>>
>>> Having the sector_identifier_uri as a hard requirement seems safer, but
>>> it's also means more work implementing a client. Leaving it optional is a
>>> lot more scary.
>>>
>>>
>>> On Thu, 18 Aug 2016 at 10:45 Stian Thorgersen <sthorger at redhat.com>
>>> wrote:
>>>
>>>> Makes sense to make this pluggable. The default should
>>>> probably SHA-256( sector_identifier || local_sub || salt ).
>>>>
>>>> We would love a PR for this, but there's a few bits required:
>>>>
>>>> * OIDC clients need option for subject type and sector_identifier_uri.
>>>> If not set it should default to public so existing clients continue to
>>>> work. These options can just be set as client attributes so there's no need
>>>> to update db schema
>>>> * Admin console update for the above
>>>> * PairwiseSubGeneratorSpi and default implementation
>>>> * Generation of salt for clients. This should be done when a client
>>>> sets subject type to pairwise
>>>> * Tests and docs
>>>>
>>>> I'd say the PairwiseSubGeneratorSpi signature should probably be:
>>>>
>>>> * public String getPairwiseSub(UserModel user, ClientModel client)
>>>>
>>>> It might even be an option to let the default PairwiseSubGenerator
>>>> provider create the salt and store it as an attribute on the client, making
>>>> that part pluggable as well.
>>>>
>>>> On 17 August 2016 at 15:59, Martin Hardselius <
>>>> martin.hardselius at gmail.com> wrote:
>>>>
>>>>> I'm going to bump this, as I want to continue the discussion/provide
>>>>> some input.
>>>>>
>>>>> Does it make sense to support more than type of pairwise subject
>>>>> identifier generator? E.g through a PairwiseSubGeneratorSpi?
>>>>>
>>>>> Let's say I want to generate the pairwise sub as a salted hash: sub =
>>>>> SHA-256( sector_identifier || local_sub || salt )
>>>>> To me, it makes sense to allow for per-client salts. These salts
>>>>> should probably be generated and persisted during client creation. Thoughts?
>>>>>
>>>>> On Fri, 12 Aug 2016 at 09:57 Martin Hardselius <
>>>>> martin.hardselius at gmail.com> wrote:
>>>>>
>>>>>> Thank you for your response. Did not see that ticket before. Great
>>>>>> news!
>>>>>>
>>>>>> I looked into using protocol mappers to achieve this, and while it
>>>>>> would work I'm worried that once KEYCLOAK-3422 has been resolved and
>>>>>> included in a proper release we would run into migration issues if the
>>>>>> method used for calculating "native" pairwise subs is different from what
>>>>>> we implement. Clients could loose / be forced to re-register all their
>>>>>> users if we decide to switch. The example methods in the spec are just
>>>>>> that. Examples. Maybe the method/alg for computing the pairwise sub should
>>>>>> be pluggable?
>>>>>>
>>>>>> --
>>>>>> Martin
>>>>>>
>>>>>> On Thu, 11 Aug 2016 at 17:15 Marek Posolda <mposolda at redhat.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Sorry for late response.
>>>>>>>
>>>>>>> We have JIRA created for that. You can possibly add yourself as a
>>>>>>> watcher. See https://issues.jboss.org/browse/KEYCLOAK-3422
>>>>>>>
>>>>>>> Maybe an alternative for you is to use protocolMappers. That should
>>>>>>> allow you to "construct" the token for particular client exactly how you
>>>>>>> want and also use the different value for "sub" claim.
>>>>>>>
>>>>>>> Another possibility is, to handle this on adapter side. We already
>>>>>>> have an adapter option "principal-attribute", which specifies that
>>>>>>> application will see the different attribute instead of "sub" as subject.
>>>>>>> For example when in appllication you call "httpServletRequest.getRemoteUser()"
>>>>>>> it will return "john" instead of "123456-unique-johns-uuid" . See
>>>>>>> https://keycloak.gitbooks.io/securing-client-applications-
>>>>>>> guide/content/v/2.1/topics/oidc/java/java-adapter-config.html
>>>>>>>
>>>>>>> Hopefully some of the options can be useful for you?
>>>>>>>
>>>>>>> Marek
>>>>>>>
>>>>>>>
>>>>>>> On 02/08/16 14:13, Martin Hardselius wrote:
>>>>>>>
>>>>>>> Me and my team are working towards getting Keycloak, customized for
>>>>>>> our needs, into production but we've identified the need for Pairwise
>>>>>>> Subject Identifiers as we don't want to expose internal user ids.
>>>>>>>
>>>>>>> Right now, the only subject_types_supported seems to be "public".
>>>>>>> Are there any near-future plans to include "pairwise"? Can we pitch in with
>>>>>>> a PR to make this happen as soon as possible?
>>>>>>>
>>>>>>> Links to relevant sections in the spec:
>>>>>>>
>>>>>>> http://openid.net/specs/openid-connect-core-1_0.html#SubjectIDTypes
>>>>>>> http://openid.net/specs/openid-connect-core-1_0.html#PairwiseAlg
>>>>>>>
>>>>>>> --
>>>>>>> Martin
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> keycloak-dev mailing listkeycloak-dev at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/keycloak-dev
>>>>>>>
>>>>>>>
>>>>>>>
>>>>> _______________________________________________
>>>>> keycloak-dev mailing list
>>>>> keycloak-dev at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/keycloak-dev
>>>>>
>>>>
>>>>
>>
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