OID4VP - specifying the signature algorithm crashes the "presentation flow"

[cvetojevichbojan]

When performing an OpenID4VP presentation if we specify the signature algorithm ES256 when generating the response (as in the examples), the process fails with the following error:

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at com.nimbusds.jose.JWSAlgorithm.parse(JWSAlgorithm.java:257)
at eu.europa.ec.eudi.wallet.internal.OpenId4VpUtilsKt.serializeWithKeyBinding(OpenId4VpUtils.kt:340)
at eu.europa.ec.eudi.wallet.internal.OpenId4VpUtilsKt$verifiablePresentationForSdJwtVc$2.invokeSuspend(OpenId4VpUtils.kt:408)

Omitting the signature algorithm fixes the issue.

Debugging the issue was difficult and i couldn't easily determine how the NPE error occurs as there seemed to be some kind of context switch when going through the OpenId4VpUtils#serializeWithKeyBinding method that would throw the error.

I have not tried other combinations of algorithms.

Steps to Reproduce:

In the EUDI android wallet ui demo app, in WalletCorePresentationControllerImpl modify the line 377 and add Algorithm.EP256 as a parameter.

Create a verifier request of Presentation Query Type: Presentation Exchange and try to transfer a sd_jwt pid document.

[mgiakkou]

Dear @cvetojevichbojan,

Thank you for bringing that into our attention. We will be looking into this soon and come to you.

Thank you,
Michalis.