X509CertificateHolder holder = builder.build(contentSigner);
X509Certificate certificate = (X509Certificate) CertificateUtils.getCertificateFromFile(holder.getEncoded(), CertificateType.X509);
PrivateKey privateKey = request.getPrivateKey();
Identity identity = new Identity(privateKey, new Certificate[] { certificate });
CertificateResponse response = new CertificateResponse(identity);
return response;
}