JAVA8 通过根证书及私钥生成子证书。

最近需要添加EMQX的双向认证。通过服务器生成根证书的子证书及私钥发送给设备。

 话不多说。直接上DEMO

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.io.IoUtil;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.Security;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.Base64;
import java.util.Date;
import lombok.SneakyThrows;
import org.bouncycastle.asn1.x500.X500Name;
import org.bouncycastle.asn1.x500.X500NameBuilder;
import org.bouncycastle.asn1.x500.style.BCStyle;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.operator.ContentSigner;
import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
import sun.misc.BASE64Decoder;

/**
 * @author TanJ
 * @date 2021/11/16 17:20
 */
public class X509 {

//私钥
 private static final St