Credential registry authentication

[F-Node-Karlsruhe]

First draft

Authenticated registry requests shall be performed doing a POST request carrying the authentication. As a first option we chose verifiable presentations (VPs) as the mean authentication. VPs already take over the authentication of the requesting identity by design and are a proven building block of the DID ecosystem. Further they can contain verifiable credentials which may be needed for authentication as well, e.g. GS1LicenceCredentials.

Open questions

Replay attacks

Option 1
Obtain challenge for the VP via an additional endpoint registry/{id}/challenge

Option 2
Add an expirationDate with a short delay to the VP (not intended (?) in the data model but possible with the LinkedDataSignature)

Protocol options

Allow OpenID4VP from the registry side?

• Registry provides presentation request for each route
• direct_post route is the route of the subject.id request which is then used to fetch the credentials in an authenticated way

-> Out of scope of OID4VC/little bit of misuse of the protocol
-> privacy issue: the necessary authentication requirements are partially revealed with the presentation request

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Preview | Diff

[F-Node-Karlsruhe]

OID4VP Draft

Using the authorize endpoint of authorization request of OID4VP using the cross device flow.

For the registry authorization the flow starts at step 2 (2.0 in figure) where wallet of the requesting wallet can query the Request Object containing the presentation definition and nonce/challenge (2.5). The first stop can be skipped, as we define the endpoint where the Requst Object can be fetched under registry{id}/authorize. After creating the requested authorizing presentation it can be send to the response_uri (3) which SHOULD be set to the original registry endpoint registry/{id}.

Till here we strictly followed the OID4VP cross device flow. The only difference comes after the official flow finished. Instead of ending the flow with a 200 response after the presentation was sent to the response_uri via post request, the response_uri answers with 200 and the requested credentials in the response body.

[msporny]

This PR has been a draft for over a year. We don't want to keep PRs open for this long on the repository, which is undergoing some fairly significant restructuring at this point. Please confirm that you still want to pursue this PR @F-Node-Karlsruhe, and if not, please close the PR.

[msporny]

@F-Node-Karlsruhe second ping to provide feedback on this PR. If we don't get any feedback from you within the next 14 days, we will close this PR.

[F-Node-Karlsruhe]

This is far from ready and the funding project terminated last month, so i will close it here myself. Thanks for pinging me :)