OpenID4VP / SD-JWT VC verifier (v6.6)

SdJwtVcVerifier validates the dc+sd-jwt presentations: the issuer signature and trust, the selective disclosures, the holder binding and the credential status. It is registered by default, but trusts no issuer until you configure trusted issuers.

See also:

  ▸ OpenID4VP overview

  ▸ Response validation and verifiers

  ▸ mdoc verifier

  ▸ DCQL queries, user profiles and logging

1) Dependencies

The verifier relies on the EUDI SD-JWT library, which is not included by default:

<dependency>
    <groupId>eu.europa.ec.eudi</groupId>
    <artifactId>eudi-lib-jvm-sdjwt-kt</artifactId>
    <version>0.20.1</version>
</dependency>

Without it, SdJwtVcVerifier throws an OpenId4VpException when validating a credential, with a message identifying the dependency to add. Applications replacing it with their own CredentialVerifier do not need EUDI.

If you also use the mdoc verifier, align the Kotlin dependencies as explained in Kotlin alignment.

2) Quick start

// trustedIssuers: see "Trusted issuers" in Response validation and verifiers
config.addCredentialVerifier(new SdJwtVcVerifier().setTrustedIssuers(trustedIssuers));
config.setDcqlQuery(EudiPidQuery.sdJwtVc(GIVEN_NAME, AGE_OVER_18));

3) What is verified

• Issuer signature and trust: typ=dc+sd-jwt and vct are required, and an iss claim or an x5c chain, checked by the trusted issuers.
• Disclosures: EUDI verifies the disclosure hashes. iss, vct and aka_vcts must not be selectively disclosed.
• Validity: exp and nbf are checked, without tolerance.
• Key-binding JWT, when present: its signature, typ=kb+jwt and sd_hash, then the holder binding.

4) Holder binding

The key-binding JWT must match the transaction’s saved request:

• Clock skew: the iat window has a 30-second tolerance, configurable through clockSkewSeconds.
• Missing proof: a presentation without key binding is reported as such and rejected by the common DCQL validator, unless the query explicitly sets require_cryptographic_holder_binding to false.
• Invalid proof: a present but invalid proof is always rejected.

5) Supported presentations

• Capabilities: the accepted algorithms are advertised in vp_formats_supported, as sd-jwt_alg_values and kb-jwt_alg_values.
• Types: besides vct, the other types the issuer signed in aka_vcts are reported in VerifiedCredential.getAdditionalTypes() and matched against the vct_values of the DCQL query. The type metadata is not used.

6) Claims and profile identifier

The claims are the reconstructed JSON payload: nested objects and arrays keep their structure, digests are removed, and an undisclosed claim is absent, which is not an error:

{
  "iss": "https://issuer.example",
  "vct": "urn:eudi:pid:1",
  "given_name": "Erika",
  "address": {"locality": "Berlin"}
}

The issuer is the configured iss or, with an x5c chain, the leaf certificate subject (RFC 2253): the iss claim is then kept as a mere claim.

The default profile identifier, ProfileIdResolver.issuerAndClaim("sub"), reads a top-level claim and combines it with the issuer; it checks at initialization that the DCQL query can return that claim. EudiWalletClient has no default: choose a stable claim, such as ProfileIdResolver.issuerAndClaim(PERSONAL_ADMINISTRATIVE_NUMBER) where the PID provider issues it.

7) Credential status

Credential status is not checked automatically, and no status list is fetched. A credential containing a status claim is rejected unless setStatusChecker(...) is configured:

• the checker receives the cryptographically verified credential, including its reconstructed claims;
• it must throw if the status is invalid, unsupported or cannot be checked;
• if it uses a status list, it must retrieve it if needed, authenticate it and check its validity and the credential’s status entry.

A credential without a status claim does not invoke the checker.

8) Scope and limits

This is a minimal SD-JWT VC integration, not a complete EUDI trust-list or HAIP validation implementation. EUDI provides the parsing, the disclosure verification and the key-binding JWT signature checks; pac4j supplies the transaction binding, the issuer trust and the profile mapping.