@AccessesPartialKey
  public static PublicKeyVerify create(RsaSsaPssPublicKey key) throws GeneralSecurityException {

    KeyFactory kf = EngineFactory.KEY_FACTORY.getInstance("RSA");
    RSAPublicKey publicKey =
        (RSAPublicKey)
            kf.generatePublic(
                new RSAPublicKeySpec(key.getModulus(), key.getParameters().getPublicExponent()));
    RsaSsaPssParameters params = key.getParameters();
    return new RsaSsaPssVerifyJce(
        publicKey,
        HASH_TYPE_CONVERTER.toProtoEnum(params.getSigHashType()),
        HASH_TYPE_CONVERTER.toProtoEnum(params.getMgf1HashType()),
        params.getSaltLengthBytes(),
        key.getOutputPrefix().toByteArray(),
        key.getParameters().getVariant().equals(RsaSsaPssParameters.Variant.LEGACY)
            ? new byte[] {0}
            : new byte[0]);
  }
RsaSsaPss (i.e. RSA Signature Schemes with Appendix (SSA) using PSS encoding) verifying with JCE.
java_src/src/main/java/com/google/crypto/tink/subtle/RsaSsaPssVerifyJce.java