Possibility of validating presentation without validating credentials

[fabrii]

Hello!

It would be great if vc.verify(presentation) had an option to validate only the presentation, without verifying the embedded credentials.
The reason behind this is that in some workflows, credentials may be validated separately, and we only need to verify the presentation, such as:

• The challenge
• The signature
• The issued date (?)
• That the holder of the VP matches the subject of the enclosed VCs (?)
• Other VP validations

Would you consider supporting this use case (e.g., with a skipCredentialVerification flag)?

Thanks!

[nklomp]

That only would make sense if you perform no holder binding whatsoever. Typically, you would inspect the VCs in a presentation to be bound to the same key, providing the presentation.

I am not related to this lib, but I would be very cautious with implementing something like that as it is very easy to make mistakes if you do not know what you are doing.

[fabrii]

I think the library can validate holder binding without having to fully validate the inner credentials (eg, cv signatures and revocation status). I might be wrong about this.

I will give a concrete example using Learner Credential Wallet:

In LCW, there is a VerificationCard component that can receive the rawCredentialRecord and handle the logic of the credential verification. In this case, the presentation can be validated first, and after that let the VerificationCard component validate the CV on his own. To my understanding, LCW is not going to act as a verifier of presentations, so there is no problem here, but the same pattern might be applicable to other verifier implementations.

Additionally, in cases where a presentation contains multiple credentials, this approach could allow validating them one at a time as needed.

As a side note, the library already supports an "unsignedPresentation" flag for skipping VP signature validation.