Java读取证书报错：java.io.IOException: Unknown named curve: 1.2.156.10197.1.301

证书格式为X.509。将证书直接写在服务端代码内，尝试用Java解析证书并获取公钥
代码如下：

try{
           
    CertificateFactory CF = CertificateFactory.getInstance("X.509"); // 从证书工厂中获取X.509的单例类
    InputStream fileIn = new FileInputStream("F:XH3.0base64X509.cer"); // 将本地证书读入文件流
    Certificate C = CF.generateCertificate(fileIn);  // 将文件流的证书转化为证书类
    String  certificateStr = C.toString();
    System.out.println("使用[自带库函数]读入证书结果如下：");
    System.out.print(certificateStr);
    System.out.println("--------------------------------------n证书主要字段:");
    X509Certificate cer = (X509Certificate)C;
    System.out.println("版本号：" + cer.getVersion());
    System.out.println("序列号：" + cer.getSerialNumber().toString());
    System.out.println("颁发者：" + cer.getSubjectDN());     // System.out.println("颁发者唯一标识符: " + cer.getSubjectUniqueID().toString());
    System.out.println("使用者：" + cer.getIssuerDN());
    //  System.out.println("使用者唯一标识符: " + cer.getIssuerUniqueID().toString());
    System.out.println("有效期：from：" + cer.getNotBefore() + "  to: " + cer.getNotAfter());
    System.out.println("签发算法" + cer.getSigAlgName());
    System.out.println("签发算法ID：" + cer.getSigAlgOID());
    System.out.println("证书签名:" + cer.getSignature().toString());
    byte [] sig = cer.getSigAlgParams();
    PublicKey publicKey = cer.getPublicKey();
    byte [] pkenc = publicKey.getEncoded();
    System.out.println("解析出的公钥:" + base64.getEncoder().encodeToString(pkenc));
    System.out.println("公钥：");
    for(int i = 0; i < pkenc.length; i++){
        System.out.print(pkenc[i]);
    }
} catch(Exception e){
    e.printStackTrace();
}

运行后报错

java.security.cert.CertificateParsingException: java.io.IOException: Unknown named curve: 1.2.156.10197.1.301
	at sun.security.x509.X509CertInfo.(X509CertInfo.java:169)
	at sun.security.x509.X509CertImpl.parse(X509CertImpl.java:1855)
	at sun.security.x509.X509CertImpl.(X509CertImpl.java:195)
	at sun.security.provider.X509Factory.engineGenerateCertificate(X509Factory.java:104)
	at java.security.cert.CertificateFactory.generateCertificate(CertificateFactory.java:339)
	at com.yunyong.ufs.api.bank.executor.client.Test.main(Test.java:89)

上网搜索得知：国密证书使用了自有的椭圆曲线，所以无法使用JDK自带的java.security解析证书（http://www.jonllen.com/jonllen/work/162.aspx）。经过调研，需要引入BouncyCastle，BC库支持国密算法。参考这篇文章（https://blog.csdn.net/jinhill/article/details/9996117）修改代码，在pom.xml增加BC库依赖：

   org.bouncycastle
   bcprov-jdk15on
   1.61

修改测试代码为

try{
    // 引入BC库
    Security.addProvider(new BouncyCastleProvider());
    // 使用BC解析X.509证书
    CertificateFactory CF = CertificateFactory.getInstance("X.509", "BC"); // 从证书工厂中获取X.509的单例类
    InputStream fileIn = new FileInputStream("F:XH3.0base64X509.cer"); // 将本地证书读入文件流
    Certificate C = CF.generateCertificate(fileIn);  // 将文件流的证书转化为证书类
    String  certificateStr = C.toString();
    System.out.println("使用[自带库函数]读入证书结果如下：");
    System.out.print(certificateStr);
    System.out.println("--------------------------------------n证书主要字段:");
    X509Certificate cer = (X509Certificate)C;
    System.out.println("版本号：" + cer.getVersion());
    System.out.println("序列号：" + cer.getSerialNumber().toString());
    System.out.println("颁发者：" + cer.getSubjectDN());     // System.out.println("颁发者唯一标识符: " + cer.getSubjectUniqueID().toString());
    System.out.println("使用者：" + cer.getIssuerDN());
    //  System.out.println("使用者唯一标识符: " + cer.getIssuerUniqueID().toString());
    System.out.println("有效期：from：" + cer.getNotBefore() + "  to: " + cer.getNotAfter());
    System.out.println("签发算法" + cer.getSigAlgName());
    System.out.println("签发算法ID：" + cer.getSigAlgOID());
    System.out.println("证书签名:" + cer.getSignature().toString());
    byte [] sig = cer.getSigAlgParams();
    PublicKey publicKey = cer.getPublicKey();
    byte [] pkenc = publicKey.getEncoded();
    System.out.println("解析出的公钥:" + base64.getEncoder().encodeToString(pkenc));
    System.out.println("公钥：");
    for(int i = 0; i < pkenc.length; i++){
        System.out.print(pkenc[i]);
    }
} catch(Exception e){
    e.printStackTrace();
}

经测试，可以正常读取证书内容

内容参考 https://www.jianshu.com/p/6390cde8f4fd?utm_campaign=maleskine&utm_content=note&utm_medium=seo_notes&utm_source=recommendation