java - 以编程方式在 java 中生成 CSR 时添加 SAN 名称

Question

我正在使用以下代码在 java 中生成 CSR:

package demo;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;

import sun.security.pkcs10.PKCS10;
import sun.security.util.DerInputStream;
import sun.security.util.DerValue;
import sun.security.x509.CertificateExtensions;
import sun.security.x509.GeneralName;
import sun.security.x509.GeneralNames;
import sun.security.x509.SubjectAlternativeNameExtension;
import sun.security.x509.X500Name;

/**
 * This class generates PKCS10 certificate signing request
 *
 * @author Pankaj@JournalDev.com
 * @version 1.0
 */
public class GenerateCSR {
    private static PublicKey publicKey = null;
    private static PrivateKey privateKey = null;
    private static KeyPairGenerator keyGen = null;
    private static GenerateCSR gcsr = null;

    private GenerateCSR() {
        try {
            keyGen = KeyPairGenerator.getInstance("RSA");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        keyGen.initialize(2048, new SecureRandom());
        KeyPair keypair = keyGen.generateKeyPair();
        publicKey = keypair.getPublic();
        privateKey = keypair.getPrivate();
    }

    public static GenerateCSR getInstance() {
        if (gcsr == null)
            gcsr = new GenerateCSR();
        return gcsr;
    }

    public String getCSR(String cn) throws Exception {
        byte[] csr = generatePKCS10(cn, "Java", "JournalDev", "Cupertino", "California", "USA");
        return new String(csr);
    }

    /**
     *
     * @param CN Common Name, is X.509 speak for the name that distinguishes the Certificate best, and ties it to your
     *        Organization
     * @param OU Organizational unit
     * @param O Organization NAME
     * @param L Location
     * @param S State
     * @param C Country
     * @return
     * @throws Exception
     */
    private static byte[] generatePKCS10(String CN, String OU, String O, String L, String S, String C)
                    throws Exception {
        GeneralNames generalNames = new GeneralNames();
        generalNames.add(new GeneralName(new DerValue("b")));
        generalNames.add(new GeneralName(new DerValue("a")));

        CertificateExtensions ext = new CertificateExtensions();

        ext.set(SubjectAlternativeNameExtension.NAME, new SubjectAlternativeNameExtension(generalNames));

        // generate PKCS10 certificate request
        String sigAlg = "MD5WithRSA";
        PKCS10 pkcs10 = new PKCS10(publicKey);
        Signature signature = Signature.getInstance(sigAlg);
        signature.initSign(privateKey);
        // common, orgUnit, org, locality, state, country
        X500Name x500Name = new X500Name(CN, OU, O, L, S, C);
        pkcs10.encodeAndSign(x500Name, signature);
        ByteArrayOutputStream bs = new ByteArrayOutputStream();
        PrintStream ps = new PrintStream(bs);
        pkcs10.print(ps);
        byte[] c = bs.toByteArray();
        try {
            if (ps != null)
                ps.close();
            if (bs != null)
                bs.close();
        } catch (Throwable th) {
        }
        return c;
    }

    public PublicKey getPublicKey() {
        return publicKey;
    }

    public PrivateKey getPrivateKey() {
        return privateKey;
    }

    public static void main(String[] args) throws Exception {
        GenerateCSR gcsr = GenerateCSR.getInstance();

        System.out.println("Public Key:\n" + gcsr.getPublicKey().toString());

        System.out.println("Private Key:\n" + gcsr.getPrivateKey().toString());
        String csr = gcsr.getCSR("journaldev.com <https://www.journaldev.com>");
        System.out.println("CSR Request Generated!!");
        System.out.println(csr);
    }

}

如您所见，我正在使用以下代码添加 SAN 名称

      GeneralNames generalNames = new GeneralNames();
        generalNames.add(new GeneralName(new DerValue("b")));
        generalNames.add(new GeneralName(new DerValue("a")));

        CertificateExtensions ext = new CertificateExtensions();

        ext.set(SubjectAlternativeNameExtension.NAME, new SubjectAlternativeNameExtension(generalNames));

我的问题是:

这是正确的方法吗？

如果是如何使用 CertificateExtensions 的对象以及在哪里传递它。

我指的是 this问题，有人提到我必须在我的证书的构造函数中传递它，但我不能 X500Name 的构造函数只允许字符串值。

Answer 1

正如我在评论中所说，sun.*类并不打算被其他程序员使用，我个人永远不会使用它们。 BouncycaSTLe 库可以做这一切，甚至更多。但是，如果您坚持使用这些类，那么您将需要使用更多才能获得预期的效果。注意:由于没有记录这些类(class)，我在这里所拥有的主要是实验的结果。
请注意，MD5 不能用于签名，这样的应用程序完全不安全。我已将其替换为 SHA256。
考虑一下我修改过的这段代码。名称本身只是示例:

// ...

import sun.security.pkcs10.PKCS10Attribute;
import sun.security.pkcs10.PKCS10Attributes;
import sun.security.x509.*;
import sun.security.pkcs10.PKCS10;
import sun.security.pkcs.PKCS9Attribute;

// ....

GeneralNames generalNames = new GeneralNames();
generalNames.add(new GeneralName(new DNSName("a.example.com")));
generalNames.add(new GeneralName(new DNSName("never.ever.example.com")));
generalNames.add(new GeneralName(new IPAddressName("192.168.1.250")));
CertificateExtensions ext = new CertificateExtensions();

ext.set(SubjectAlternativeNameExtension.NAME, new SubjectAlternativeNameExtension(generalNames));
var pkcs9Attr = new PKCS9Attribute(PKCS9Attribute.EXTENSION_REQUEST_OID, ext);
var pkcs10Attrs = new PKCS10Attributes(new PKCS10Attribute[] {
    new PKCS10Attribute(pkcs9Attr)
});

// generate PKCS10 certificate request
String sigAlg = "SHA256WithRSA";
PKCS10 pkcs10 = new PKCS10(publicKey, pkcs10Attrs);
Signature signature = Signature.getInstance(sigAlg);
signature.initSign(privateKey);
// common, orgUnit, org, locality, state, country
X500Name x500Name = new X500Name(CN, OU, O, L, S, C);
pkcs10.encodeAndSign(x500Name, signature);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
PrintStream ps = new PrintStream(bs);
pkcs10.print(ps);

这应该会产生一个带有适当的 subjectAltName 扩展的 PKCS10 证书请求。