using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using UnityEngine;

public static class EncryptionTool
{
    public static byte[] MakeMD5(byte[] kb)
    {
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();//用来给密钥进行散列
        byte[] keyhash = md5.ComputeHash(kb);//给密钥散列
        md5.Clear();//释放资源
        return keyhash;
    }

    #region 加密

    /// <summary>
    /// 使用给定密钥加密字符串
    /// </summary>
    /// <param name="original">明文</param>
    /// <param name="key">密钥</param>
    /// <returns>加密后的密文</returns>
    public static string Encrypt(this string original, string key)
    {
        byte[] buff = Encoding.Unicode.GetBytes(original);//把明文转化成二进制数组
        byte[] kb = Encoding.Unicode.GetBytes(key);//把密钥转化成二进制数组
        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();//用TripleDES算法来加密的类            
        des.Key = MakeMD5(kb);//设置TripleDES算法的密钥
        des.Mode = CipherMode.ECB;//设置算法的模式
        byte[] enByte = des.CreateEncryptor().TransformFinalBlock(buff, 0, buff.Length);
        return Convert.ToBase64String(enByte);
    }

    /// <summary>
    /// 使用默认密钥加密
    /// </summary>
    /// <param name="original">明文</param>
    /// <returns>加密后的密文</returns>
    public static string Encrypt(this string original)
    {
        return Encrypt(original, "ldq");
    }
    #endregion

    #region 解密
    /// <summary>
    /// 使用指定的密钥解密
    /// </summary>
    /// <param name="encrypted">加密过后的密码</param>
    /// <param name="key">密钥（密钥的明文）</param>
    /// <returns>密码对应的明文</returns>
    public static string Decrypt(this string encrypted, string key)
    {
        byte[] buff = Convert.FromBase64String(encrypted);
        byte[] kb = Encoding.Unicode.GetBytes(key);
        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
        des.Key = MakeMD5(kb);
        des.Mode = CipherMode.ECB;
        byte[] original = des.CreateDecryptor().TransformFinalBlock(buff, 0, buff.Length);//获取明文的byte数组
        return Encoding.Unicode.GetString(original);//转化成字符串，并返回
    }

    public static string Decrypt(this string encrypted)
    {
        return Decrypt(encrypted, "ldq");
    }
    #endregion

}