package com.ym.mec.collectfee.utils;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.Key;
import java.util.Base64;

public class CDesECB
{
    public static final String ALGORITHM_DES = "DES/ECB/PKCS5Padding";

    /**
     * 加密
     * @param data 待加密字符串
     * @param key 加密私钥，长度不能够小于8位
     * @return 加密后的字节数组，一般结合Base64编码使用
     */
    public static String encode(String key, String data) throws Exception
    {
        return encode(key, data.getBytes());
    }
    /**
     * 加密
     * @param data 待加密字符串
     * @param key 加密私钥，长度不能够小于8位
     * @return 加密后的字节数组，一般结合Base64编码使用
     */
    public static String encode(String key, byte[] data) throws Exception
    {
        try
        {
            DESKeySpec dks = new DESKeySpec(key.getBytes());
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            // key的长度不能够小于8位字节
            Key secretKey = keyFactory.generateSecret(dks);
            Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            byte[] bytes = cipher.doFinal(data);
            return Base64.getEncoder().encodeToString(bytes);
        }
        catch (Exception e)
        {
            throw new Exception(e);
        }
    }
    /**
     * 解密
     * @param data 待解密字符串
     * @param key 解密私钥，长度不能够小于8位
     * @return 解密后的字节数组
     * @throws Exception 异常
     */
    public static byte[] decode(String key, byte[] data) throws Exception
    {
        try
        {
            DESKeySpec dks = new DESKeySpec(key.getBytes());
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            // key的长度不能够小于8位字节
            Key secretKey = keyFactory.generateSecret(dks);
            Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return cipher.doFinal(data);
        }
        catch (Exception e)
        {
            throw new Exception(e);
        }
    }

    /**
     * 获取编码后的值
     *
     * @param key
     * @param data
     * @return
     * @throws Exception
     */
    public static String decodeValue(String key, String data)
    {
        byte[] datas;
        String value = null;
        try
        {
            if (System.getProperty("os.name") != null
                    && (System.getProperty("os.name").equalsIgnoreCase("sunos") || System
                    .getProperty("os.name").equalsIgnoreCase("linux")))
            {
                datas = decode(key, Base64.getDecoder().decode(data));
            }
            else
            {
                datas = decode(key, Base64.getDecoder().decode(data));
            }
            value = new String(datas);
        }
        catch (Exception e)
        {
            value = "";
        }
        return value;
    }
}
