package com.casic.missiles.util;


import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import java.security.KeyFactory;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.X509EncodedKeySpec;

/**
 *
 */

/**
 * <p>
 * RSA公钥/私钥/签名工具包
 * </p>
 * <p>
 * 罗纳德·李维斯特（Ron [R]ivest）、阿迪·萨莫尔（Adi [S]hamir）和伦纳德·阿德曼（Leonard [A]dleman）
 * </p>
 * <p>
 * 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/>
 * 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/>
 * 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全
 * </p>
 *
 * @author LWH
 * @date 2018-10-29
 */
public class RSATestUtils {
    public static String RSAPrivateKey = "RSAPrivateKey";
    public static String RSAPublicKey = "RSAPublicKey";

    public static void main(String[] args) throws Exception {
        //加密字符串
        long salt = System.currentTimeMillis();
        String timestamp = String.valueOf(salt);
        String message = "test-" + timestamp;
        String public_key = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCe6fr64/YNoKNEsA85WCsIuEL7RQIUxsveyYyGHF3f+JatpAiV2Xp5e/DK/73dWJ9xnEFzmeHFfOrs1czOolnYdLpboORZRsEI6zX+xq37EmFG631CmgQcOxw+rb1ipFPBPxC9jdBm46q2tp3hm9IChebttfKCIAoq9j0HFh1/CwIDAQAB";
        String messageEn = encrypt(message, public_key);
        System.out.println(message + "\t加密后的字符串为:" + messageEn);
    }


    /**
     * RSA公钥加密
     *
     * @param str       加密字符串 
     * @param publicKey 公钥
     * @return 密文
     * @throws Exception 加密过程中的异常信息
     */
    public static String encrypt(String str, String publicKey) throws Exception {
        //base64编码的公钥
        byte[] decoded = Base64.decodeBase64(publicKey);
        RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
        //RSA加密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
        return outStr;
    }
}