Support JWKS_URI for trust grant issuer

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Ory Network Project

No response

Describe your problem

We have an external certificate management solution. We use Hydra for a RFC 7523 flow. https://www.ory.sh/docs/reference/api#tag/oAuth2/operation/trustOAuth2JwtGrantIssuer require you to specify the JWKS contents directly. This means we need to manage and sync JWKS changes across 2 systems.

As raised in slack: https://ory-community.slack.com/archives/C010F7Z4XM1/p1746693126158829

Describe your ideal solution

Ideally https://www.ory.sh/docs/reference/api#tag/oAuth2/operation/trustOAuth2JwtGrantIssuer should support jwks_uri
the same way as (and in fact recommended in) https://www.ory.sh/docs/reference/api#tag/oAuth2/operation/createOAuth2Client

Workarounds or alternatives

We don't see any straightforward workaround for this problem.

Version

2.3.0

Additional Context

It appears that the client_assertion already support either JSONWebKeysURI or JSONWebKeys directly in https://github.com/ory/fosite/blob/8052806a6efe52832867d24cd41b17463190903d/client.go#L95

Ideally we would like to have a similar mechanism for the assertion parameter in the token request.

Please give an indication as to the likelihood and possible timeline for such a feature. Alternatively, your view on the likelihood that a contribution PR based on the description would be admitted.