CertificateFactory cf = CertificateFactory.getInstance("X.509", "BC");
X509Certificate rootCert = (X509Certificate)cf.generateCertificate(new ByteArrayInputStream(rootCertBin));
X509Certificate userCert1 = (X509Certificate)cf.generateCertificate(new ByteArrayInputStream(userCert1Bin));
X509Certificate userCert2 = (X509Certificate)cf.generateCertificate(new ByteArrayInputStream(userCert2Bin));
X509CRL crl = (X509CRL)cf.generateCRL(new ByteArrayInputStream(crlBin));
rootCert.verify(rootCert.getPublicKey(), "BC");
userCert1.verify(rootCert.getPublicKey(), "BC");
crl.verify(rootCert.getPublicKey(), "BC");