读取Cert格式证书的密钥

不想存储Cert证书内容，只想存储证书密钥，可通过以下2種方式实现

一、通過java读取证书的密钥出来：

 package com.zat.ucop.service.util;

 import sun.misc.BASE64Encoder;

 import java.io.FileInputStream;
 import java.security.PublicKey;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;

 /**
  * 读取cert格式证书的密钥.
  *
  * @author weixiong.cao
  * @date 2019/4/3
  */
 public class ReadCerDemo {
     public static void main(String[] args) throws Exception {
         String keyStorePath = "E:/mpay公钥/client_02.cer";

         CertificateFactory cf = CertificateFactory.getInstance("X.509");
         X509Certificate cert = (X509Certificate) cf.generateCertificate(new FileInputStream(keyStorePath));
         PublicKey publicKey = cert.getPublicKey();
         BASE64Encoder base64Encoder = new BASE64Encoder();
         String publicKeyString = base64Encoder.encode(publicKey.getEncoded());
         System.out.println("-----------------公钥--------------------");
         System.out.println(publicKeyString);
         System.out.println("-----------------公钥--------------------");
     }
 }

二、通過openssl命令讀取

進入linux控制臺，輸入以下命令：

openssl x509 -in ./client_02.cer -pubkey -noout > ./mpayPubKey.pubkey

以上命令會將證書內容生成到一個 mpayPubKey.pubkey 文件，文件內容如下：