一、Des算法

import java.security.SecureRandom;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
public class DesUtil {
    public static void main(String[] args) throws Exception{
        // 8位及以上
        String defaultKey = "12345678";
        String data = "Grand_xxx@";
        // 對字符串進行加密
        String encryptStr = Base64.getEncoder().encodeToString(encrypt(data.getBytes(), defaultKey.getBytes()));
        System.out.println("encryptStr = " + encryptStr);
        // 對加密字符串進行解密
        String decryptStr = new String(decrypt(Base64.getDecoder().decode(encryptStr), defaultKey.getBytes()));
        System.out.println("decryptStr = " + decryptStr);
    }
    private final static String DES = "DES";
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一個可信任的隨機數源
        SecureRandom sr = new SecureRandom();
        // 從原始密鑰數據創建DESKeySpec對象
        DESKeySpec dks = new DESKeySpec(key);
        // 創建一個密鑰工廠，然后用它把DESKeySpec轉換成SecretKey對象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);
        // Cipher對象實際完成加密操作
        Cipher cipher = Cipher.getInstance(DES);
        // 用密鑰初始化Cipher對象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
        return cipher.doFinal(data);
    }
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一個可信任的隨機數源
        SecureRandom sr = new SecureRandom();
        // 從原始密鑰數據創建DESKeySpec對象
        DESKeySpec dks = new DESKeySpec(key);
        // 創建一個密鑰工廠，然后用它把DESKeySpec轉換成SecretKey對象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);
        // Cipher對象實際完成解密操作
        Cipher cipher = Cipher.getInstance(DES);
        // 用密鑰初始化Cipher對象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
        return cipher.doFinal(data);
    }
}