package com.qgutech.util;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;

import javax.crypto.*;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;

/**
 * @author xxx
 * @date 2024/12/25 11:31
 * @description
 */
public class AESUtil {
    /**
     * 偏移量
     *
     * 说明：偏移量字符串必须是16位 当模式是CBC的时候必须设置偏移量
     * 此处值与前端偏移量值保持一致
     */
    private static String iv = "37fa77f6a3b0462d";
    private static String uniqueKey = "1234567890123456";

    /**
     * 加密算法
     */
    private static String Algorithm = "AES";

    /**
     * 算法/模式/补码方式
     */
    private static String AlgorithmProvider = "AES/CBC/PKCS5Padding";

    /**
     * 加密
     *
     * @param src 加密内容
     * @return
     * @throws Exception
     */
    public static String encrypt(String src) throws Exception {
        byte[] key = uniqueKey.getBytes();
        SecretKey secretKey = new SecretKeySpec(key, Algorithm);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(iv.getBytes("utf-8"));
        Cipher cipher = Cipher.getInstance(AlgorithmProvider);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParameterSpec);
        byte[] cipherBytes = cipher.doFinal(src.getBytes("UTF-8"));
        return byteToHexString(cipherBytes);
    }

    /**
     * 解密
     *
     * @param enc       加密内容
     * @return
     * @throws Exception
     */
    public static String decrypt(String enc) throws Exception {
        byte[] key = uniqueKey.getBytes();
        SecretKey secretKey = new SecretKeySpec(key, Algorithm);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(iv.getBytes("utf-8"));
        Cipher cipher = Cipher.getInstance(AlgorithmProvider);
        cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);
        byte[] hexBytes = hexStringToBytes(enc);
        byte[] plainBytes = cipher.doFinal(hexBytes);
        return new String(plainBytes, "UTF-8");
    }

    /**
     * 将byte数组转换为16进制字符串
     *
     * @param src
     * @return
     */
    private static String byteToHexString(byte[] src) {
        return Hex.encodeHexString(src);
    }

    /**
     * 将16进制字符串转换为byte数组
     *
     * @param hexString
     * @return
     */
    private static byte[] hexStringToBytes(String hexString) throws DecoderException {
        return Hex.decodeHex(hexString);
    }

    /**
     * AES加密、解密测试方法
     *
     * @param args
     */
    public static void main(String[] args) {
        try {
            // 唯一key作为密钥
            // 加密前数据，此处数据与前端数据一致(加密内容包含有时间戳)，请注意查看前端加密前数据
            String src = "hczd";
            System.out.println("密钥:" + uniqueKey);
            System.out.println("原字符串:" + src);
            // 加密
            String encrypt = encrypt(src);
            System.out.println("加密：" + encrypt);
            // 解密
            String decrypt = decrypt(encrypt);
            System.out.println("解密：" + decrypt);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}