did:x509 resolver: CRL check and set expires/revoked on keys #4083

Parent PRD

#4079

What to build

Extend the did:x509 resolver to perform CRL checking during DID resolution and annotate the resulting DID document's verification methods with expires and revoked metadata.

• Inject pki.Validator into the did:x509 resolver via constructor injection (NewResolver(pkiValidator))
• Update vdr.go to pass pkiValidator when constructing the resolver
• In Resolve(), after chain validation succeeds:
  • Perform CRL check via pkiValidator.CheckCRL(chain)
  • If a certificate is revoked, set Revoked on the verification method with the revocation date
  • Set Expires on the verification method from the leaf certificate's notAfter date
• Remove the CRL check and cert-time validation from X509CredentialValidator (these are now handled by the resolver)
• Remove the ad-hoc resolver instantiation in X509CredentialValidator (didx509.NewResolver() at validator.go:276)

This makes CRL and cert-time information available for any credential with a did:x509 issuer, regardless of credential type (PatientEnrollmentCredential, HealthcareProfessionalDelegationCredential, HealthcareProviderCredential, etc.).

See PRD #4079 Part A and PSA 10.4.2 / 10.4.3 for full context.

Acceptance criteria

• did:x509 resolver accepts pki.Validator via constructor injection
• CRL check is performed during Resolve() after chain validation
• Revoked field is set on the verification method when the certificate is on the CRL
• Expires field is set on the verification method from the leaf cert's notAfter
• CRL check and cert-time validation are removed from X509CredentialValidator
• Ad-hoc resolver instantiation in X509CredentialValidator is removed
• Existing X509Credential tests pass
• New test: credential with a revoked did:x509 cert gets Revoked set on the key
• New test: credential with a did:x509 cert gets Expires set from notAfter

Blocked by

• Blocked by Add expires and revoked fields to VerificationMethod (go-did) #4082 (expires/revoked fields on VerificationMethod in go-did)

User stories addressed

• User story 1: PatientEnrollmentCredentials get CRL checks
• User story 4: CRL checks at the key resolution layer for all did:x509 credentials
• User story 5: trust anchor validation at DID resolution layer
• User story 6: key validity information available for time-based checks
• User story 7: existing X509Credential behavior preserved