DES 加密解密，不变密文+动态密文

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

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;

public class DESUtil {

    public static byte[] desKey;

    static{
        try{
            desKey = initKey();
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    /*
     * 生成密钥
     */
    public static byte[] initKey() throws Exception{
        KeyGenerator keyGen = KeyGenerator.getInstance("DES");
        keyGen.init(56);
        SecretKey secretKey = keyGen.generateKey();
        return secretKey.getEncoded();
    }


    /*
     * DES 加密
     */
    public static byte[] encrypt(byte[] data, byte[] key) throws Exception{
        SecretKey secretKey = new SecretKeySpec(key, "DES");
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }


    /*
     * DES 解密
     */
    public static byte[] decrypt(byte[] data, byte[] key) throws Exception{
        SecretKey secretKey = new SecretKeySpec(key, "DES");
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }

    //==========================新版随机密文===========
    private static final String ALGORITHM = "DES";
    private static final String TRANSFORMATION = "DES/CBC/PKCS5Padding";

    /**
     * DES 加密
     *
     * @param data 明文数据
     * @param key  密钥
     * @return 加密后的密文 + IV
     * @throws Exception
     */
    public static byte[] encryptIV(byte[] data, byte[] key) throws Exception {
        // 创建 DES 密钥
        SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);

        // 生成随机的 IV
        byte[] iv = generateIV();
        IvParameterSpec ivSpec = new IvParameterSpec(iv);

        // 获取 Cipher 实例并初始化为加密模式
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);

        // 执行加密操作
        byte[] encryptedData = cipher.doFinal(data);

        // 将 IV 和加密后的数据拼接在一起返回
        byte[] result = new byte[iv.length + encryptedData.length];
        System.arraycopy(iv, 0, result, 0, iv.length);
        System.arraycopy(encryptedData, 0, result, iv.length, encryptedData.length);

        return result;
    }

    /**
     * DES 解密
     *
     * @param data 加密后的密文 + IV
     * @param key  密钥
     * @return 解密后的明文
     * @throws Exception
     */
    public static byte[] decryptIV(byte[] data, byte[] key) throws Exception {
        // 创建 DES 密钥
        SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);

        // 提取 IV
        byte[] iv = new byte[8];  // DES 的 IV 长度为 8 字节
        System.arraycopy(data, 0, iv, 0, iv.length);
        IvParameterSpec ivSpec = new IvParameterSpec(iv);

        // 提取加密后的数据
        byte[] encryptedData = new byte[data.length - iv.length];
        System.arraycopy(data, iv.length, encryptedData, 0, encryptedData.length);

        // 获取 Cipher 实例并初始化为解密模式
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);

        // 执行解密操作
        return cipher.doFinal(encryptedData);
    }

    /**
     * 生成随机的 IV
     *
     * @return 随机生成的 IV
     */
    private static byte[] generateIV() {
        byte[] iv = new byte[8];  // DES 的 IV 长度为 8 字节
        new SecureRandom().nextBytes(iv);
        return iv;
    }

    public static void main(String[] args) throws Exception {
        Base64 base64 = new Base64(0, null, true);
        String encrypt1 = base64.encodeAsString(encryptIV("1313xxxx".getBytes(StandardCharsets.UTF_8), "ah^nacy6".getBytes(StandardCharsets.UTF_8)));
        System.err.println(encrypt1);
        String decrypt1 = new String(decryptIV(base64.decode(encrypt1), "ah^nacy6".getBytes(StandardCharsets.UTF_8)));
        System.err.println(decrypt1);
        System.err.println("===========================");
        String encrypt2 = base64.encodeAsString(encryptIV("1313xxxx".getBytes(StandardCharsets.UTF_8), "ah^nacy6".getBytes(StandardCharsets.UTF_8)));
        System.err.println(encrypt2);
        String decrypt2 = new String(decryptIV(base64.decode(encrypt2), "ah^nacy6".getBytes(StandardCharsets.UTF_8)));
        System.err.println(decrypt2);
    }
}