在没有BouncyCastle的情况下用Java创建X509证书？

Question

是否可以在不使用Bouncy Castle X509V * CertificateGenerator 类的情况下，在Java代码中巧妙地创建X509证书？

Answer 1

签署证书的能力不是标准Java库或扩展的一部分。

自己做的很多代码都是核心的一部分。有些类可以编码和解码X.500名称，X.509证书扩展，各种算法的公钥，当然还有实际执行数字签名的类。

自己实现这一点并非易事，但绝对可行。我可能花了4到5天，这是我第一次为证书签名制作工作原型。这对我来说是一次梦幻般的学习练习，但是当有免费的免费图书馆时，很难证明这笔费用是合理的。

Answer 2

是的，但没有公开记录的课程。我在本文中 中记录了该过程。

import sun.security.x509.*;
import java.security.cert.*;
import java.security.*;
import java.math.BigInteger;
import java.util.Date;
import java.io.IOException

/** 
 * Create a self-signed X.509 Certificate
 * @param dn the X.509 Distinguished Name, eg "CN=Test, L=London, C=GB"
 * @param pair the KeyPair
 * @param days how many days from now the Certificate is valid for
 * @param algorithm the signing algorithm, eg "SHA1withRSA"
 */ 
X509Certificate generateCertificate(String dn, KeyPair pair, int days, String algorithm)
  throws GeneralSecurityException, IOException
{
  PrivateKey privkey = pair.getPrivate();
  X509CertInfo info = new X509CertInfo();
  Date from = new Date();
  Date to = new Date(from.getTime() + days * 86400000l);
  CertificateValidity interval = new CertificateValidity(from, to);
  BigInteger sn = new BigInteger(64, new SecureRandom());
  X500Name owner = new X500Name(dn);
 
  info.set(X509CertInfo.VALIDITY, interval);
  info.set(X509CertInfo.SERIAL_NUMBER, new CertificateSerialNumber(sn));
  info.set(X509CertInfo.SUBJECT, new CertificateSubjectName(owner));
  info.set(X509CertInfo.ISSUER, new CertificateIssuerName(owner));
  info.set(X509CertInfo.KEY, new CertificateX509Key(pair.getPublic()));
  info.set(X509CertInfo.VERSION, new CertificateVersion(CertificateVersion.V3));
  AlgorithmId algo = new AlgorithmId(AlgorithmId.md5WithRSAEncryption_oid);
  info.set(X509CertInfo.ALGORITHM_ID, new CertificateAlgorithmId(algo));
 
  // Sign the cert to identify the algorithm that's used.
  X509CertImpl cert = new X509CertImpl(info);
  cert.sign(privkey, algorithm);
 
  // Update the algorith, and resign.
  algo = (AlgorithmId)cert.get(X509CertImpl.SIG_ALG);
  info.set(CertificateAlgorithmId.NAME + "." + CertificateAlgorithmId.ALGORITHM, algo);
  cert = new X509CertImpl(info);
  cert.sign(privkey, algorithm);
  return cert;
}   

Answer 3

import sun.security.x509.*;

import java.security.cert.*;
import java.security.*;
import java.math.BigInteger;
import java.security.cert.Certificate;
import java.util.Date;
import java.io.IOException;

public class Example {
    /**
     * Create a self-signed X.509 Example
     *
     * @param dn        the X.509 Distinguished Name, eg "CN=Test, L=London, C=GB"
     * @param pair      the KeyPair
     * @param days      how many days from now the Example is valid for
     * @param algorithm the signing algorithm, eg "SHA1withRSA"
     */
    public X509Certificate generateCertificate(String dn, KeyPair pair, int days, String algorithm)
            throws GeneralSecurityException, IOException {
        PrivateKey privkey = pair.getPrivate();
        X509CertInfo info = new X509CertInfo();
        Date from = new Date();
        Date to = new Date(from.getTime() + days * 86400000l);
        CertificateValidity interval = new CertificateValidity(from, to);
        BigInteger sn = new BigInteger(64, new SecureRandom());
        X500Name owner = new X500Name(dn);

        info.set(X509CertInfo.VALIDITY, interval);
        info.set(X509CertInfo.SERIAL_NUMBER, new CertificateSerialNumber(sn));
        info.set(X509CertInfo.SUBJECT, owner);
        info.set(X509CertInfo.ISSUER, owner);
        info.set(X509CertInfo.KEY, new CertificateX509Key(pair.getPublic()));
        info.set(X509CertInfo.VERSION, new CertificateVersion(CertificateVersion.V3));
        AlgorithmId algo = new AlgorithmId(AlgorithmId.md5WithRSAEncryption_oid);
        info.set(X509CertInfo.ALGORITHM_ID, new CertificateAlgorithmId(algo));

        // Sign the cert to identify the algorithm that's used.
        X509CertImpl cert = new X509CertImpl(info);
        cert.sign(privkey, algorithm);

        // Update the algorith, and resign.
        algo = (AlgorithmId) cert.get(X509CertImpl.SIG_ALG);
        info.set(CertificateAlgorithmId.NAME + "." + CertificateAlgorithmId.ALGORITHM, algo);
        cert = new X509CertImpl(info);
        cert.sign(privkey, algorithm);
        return cert;
    }

    public static void main (String[] argv) throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        Example example = new Example();
        String distinguishedName = "CN=Test, L=London, C=GB";
        Certificate certificate = example.generateCertificateOriginal(distinguishedName, keyPair, 365, "SHA256withRSA");
        System.out.println("it worked!");
    }
}

我喜欢vbence的答案，但我一直得到以下异常：

java.security.cert.CertificateException：主题类类型无效。

经过多次尝试找出 一个有效的主题类后，我发现X509CerInfo想要一个X500Name的实例。

1 info.set(X509CertInfo.SERIAL_NUMBER, new CertificateSerialNumber(sn));
2 info.set(X509CertInfo.SUBJECT, new CertificateSubjectName(owner));
3 info.set(X509CertInfo.ISSUER, new CertificateIssuerName(owner));
4 info.set(X509CertInfo.KEY, new CertificateX509Key(pair.getPublic()));

第2行＆amp; 3需要改为

2 info.set(X509CertInfo.SUBJECT, owner);
3 info.set(X509CertInfo.ISSUER, owner);

Answer 4

JRE中提供了制作自签名证书（签名，X509编码等）的所有基本组件。与BC不同，Sun的JCE不提供签署证书的任何公共电话。但是，Keytool中提供了所有功能。您只需从keytool复制代码即可。您需要复制的方法是 doSelfCert（）。

Answer 5

取决于您想要做什么（可能还有您对“Sanely”的定义）。正如ZZ Coder所指出的，您可以通过复制 keytool 。但我不相信您可以使用标准JCE创建PKCS10证书请求对象，如果您想创建标准的CA签名EEC，则可能需要这样做。