@Test
    public void unsupportedDigestType() {
        ServiceTester.test("CertificateFactory")
            .withAlgorithm("X509")
            .skipProvider("SUN")
            .skipProvider("BC")
            .run((p, algorithm) -> {
                X509Certificate c = certificateFromPEM(p, MD5_SIGNATURE);
                assertThrows(NoSuchAlgorithmException.class, () -> c.verify(c.getPublicKey()));
            });
    }
Confirm that explicit EC params aren't accepted in certificates.
common/src/test/java/org/conscrypt/java/security/cert/X509CertificateTest.java