使用Java生成证书，公钥和私钥

Z时代
2024-01-10
分类：问答

我正在寻找一个Java库或代码来即时生成证书，公共和私有密钥，而无需使用第三方程序（例如openssl）。

我认为是从Java代码中获取keytool + openssl的东西。

考虑使用ssl和客户端身份验证保护的基于Java servlet的Web应用程序。我希望Servlet容器仅在请求时使用Java代码生成客户端证书（例如pkcs12格式）。

回答：

您可以使用一对或密钥在Java中动态生成证书。（公钥，私钥）。以BigInteger格式获取这些密钥，并检查以下代码以生成证书。

RSAPrivateKeySpec serPrivateSpec = new RSAPrivateKeySpec(
    new BigInteger(val of pub key), new BigInteger(val of pri key));
fact = KeyFactory.getInstance("RSA");
PrivateKey serverPrivateKey = fact.generatePrivate(serPrivateSpec);
RSAPublicKeySpec serPublicSpec = new RSAPublicKeySpec(
    new BigInteger(agentCL.getSerPubMod()), new BigInteger(agentCL.getSerPubExp()));
PublicKey serverPublicKey = fact.generatePublic(serPublicSpec);
keyStore = KeyStore.getInstance(IMXAgentCL.STORE_TYPE);
keyStore.load(null, SOMEPWD.toCharArray());
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
X509Certificate[] serverChain = new X509Certificate[1];
X509V3CertificateGenerator serverCertGen = new X509V3CertificateGenerator();
X500Principal serverSubjectName = new X500Principal("CN=OrganizationName");
serverCertGen.setSerialNumber(new BigInteger("123456789"));
// X509Certificate caCert=null;
serverCertGen.setIssuerDN(somename);
serverCertGen.setNotBefore(new Date());
serverCertGen.setNotAfter(new Date());
serverCertGen.setSubjectDN(somename);
serverCertGen.setPublicKey(serverPublicKey);
serverCertGen.setSignatureAlgorithm("MD5WithRSA");
// certGen.addExtension(X509Extensions.AuthorityKeyIdentifier, false,new
// AuthorityKeyIdentifierStructure(caCert));
serverCertGen.addExtension(X509Extensions.SubjectKeyIdentifier, false,
    new SubjectKeyIdentifierStructure(serverPublicKey));
serverChain[0] = serverCertGen.generateX509Certificate(serverPrivateKey, "BC"); // note: private key of CA
keyStore.setEntry("xyz",
    new KeyStore.PrivateKeyEntry(serverPrivateKey, serverChain),
    new KeyStore.PasswordProtection("".toCharArray()));