如何在Dart中创建证书(X509Certificate)？

import 'dart:io';
import 'dart:typed_data';

SecurityContext context = SecurityContext();

File certificateChainFile = File('path/to/certificate_chain.pem');
context.useCertificateChain(certificateChainFile.path);

File privateKeyFile = File('path/to/private_key.pem');
context.usePrivateKey(privateKeyFile.path);

File rootCertificatesFile = File('path/to/root_certificates.pem');
context.setTrustedCertificates(rootCertificatesFile.path);

X509Certificate certificate = context.certificate;