Reuse Credential Offer identifier from metadata in authorization_details Authorization Request parameter

[paulbastian]

During IETF Prague, discussion came up to reuse the identifier used in Credential Offer that was introduced with #86 in the Authorization Request with authorization_details, e.g.:

[
   {
      "type": "openid_credential",
      "credential_description": "UniversityDegreeCredential"
   }
]

[tlodderstedt]

I think this makes sense. We should have done this when we introduced the credential identifiers.

[markuskreusch]

From an implementation perspective this seems reasonable. I so far preferred the scope over the authorization details because it was a single identifier that could reference the credential in the metadata. With this approach the same is possible but in a more concise way and without the need for a scope per credential.

Especially with SD-JWTs there could be some confusion of the type used here for the authorization_details with the credentials_supported array in the issuer metadata, where each supported SD-JWT has a type as well. As far as I understood this will be called vct in the future and thus be distinguishable from each other. JWT VCs have types as well. The spec could stress, that this is a different type.

[Sakurann]

agreed this makes sense. looks like ready for PR

[paulbastian]

@tlodderstedt @Sakurann so you see this as an optional alternative or the only way to use authorisation details?

[Sakurann]

I would say the only way.

[paulbastian]

That's also my perception. Is it ready for PR?