// Converts to java.security
public static java.security.cert.X509Certificate convert(javax.security.cert.X509Certificate cert) {
    try {
        byte[] encoded = cert.getEncoded();
        ByteArrayInputStream bis = new ByteArrayInputStream(encoded);
        java.security.cert.CertificateFactory cf
            = java.security.cert.CertificateFactory.getInstance("X.509");
        return (java.security.cert.X509Certificate)cf.generateCertificate(bis);
    } catch (java.security.cert.CertificateEncodingException e) {
    } catch (javax.security.cert.CertificateEncodingException e) {
    } catch (java.security.cert.CertificateException e) {
    }
    return null;
}

// Converts to javax.security
public static javax.security.cert.X509Certificate convert(java.security.cert.X509Certificate cert) {
    try {
        byte[] encoded = cert.getEncoded();
        return javax.security.cert.X509Certificate.getInstance(encoded);
    } catch (java.security.cert.CertificateEncodingException e) {
    } catch (javax.security.cert.CertificateEncodingException e) {
    } catch (javax.security.cert.CertificateException e) {
    }
    return null;
}