記一次 實現 license授權

package com.example.demo;


import com.alibaba.fastjson.JSON;
import com.google.common.collect.ImmutableMap;

import javax.crypto.Cipher;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.util.Map;

/**
 * @author yangxj
 * @date 2020-04-10 14:17
 */
public class RSADemo {
    /**
     * 生成一對公（私）鑰
     * @throws Exception
     */
    public static void genPairKey() throws Exception {
        //實例化Key
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        //獲取一對鑰匙
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        //獲得公鑰
        Key publicKey = keyPair.getPublic();
        //獲得私鑰
        Key privateKey = keyPair.getPrivate();

        // 公（私）鑰寫入 文件
        FileOutputStream publicFos = new FileOutputStream("/Users/edz/licensedir/public.key");
        FileOutputStream privateFos = new FileOutputStream("/Users/edz/licensedir/private.key");

        ObjectOutputStream outputStream = new ObjectOutputStream(publicFos);

        ObjectOutputStream outputStream2 = new ObjectOutputStream(privateFos);

        outputStream.writeObject(publicKey);

        outputStream2.writeObject(privateKey);

        outputStream2.close();
        outputStream.close();
    }

    /**
     * 解析
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");

        // 反序列化 獲取 公（私）鑰
        FileInputStream fis1 = new FileInputStream("/Users/edz/licensedir/public.key");
        FileInputStream fis2 = new FileInputStream("/Users/edz/licensedir/private.key");

        ObjectInputStream objectStream1 = new ObjectInputStream(fis1);
        ObjectInputStream objectStream2 = new ObjectInputStream(fis2);

        Key publicKey = (Key)objectStream1.readObject();
        Key privateKey = (Key)objectStream2.readObject();
        
        objectStream1.close();
        objectStream2.close();

        // 要加密的內容
        Map authInfo = ImmutableMap.of("授權", "某人", "授權有效期至", "2019-12-01");

        //用公（私）鑰加密
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        byte [] encodeResult = cipher.doFinal(JSON.toJSONBytes(authInfo));

        //用私（公）鑰匙解密
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        byte[] bytes = cipher.doFinal(encodeResult);

        System.out.println(new String(bytes));


    }
}