AsymmetricKeyParameter caPrivateKeyParameters = PrivateKeyFactory.createKey(signerPrivateKey.getEncoded());
ContentSigner contentSigner = new BcRSAContentSignerBuilder(sigAlgId, digestAlgId)
.build(caPrivateKeyParameters);
X509CertificateHolder certificateHolder = certificateBuilder.build(contentSigner);
Certificate certificate = certificateHolder.toASN1Structure();
return certificate;
} catch (OperatorCreationException e) {
throw new OpsException("Error signing certificate", e);
} catch (IOException e) {