using System.Security.Cryptography;
using System.Text;

namespace Cowain.Base.Helpers;

public class DESHelper
{

    public static string Encrypt(string password, string key)
    {
        if (key.Length != 8)
        {
            return "";
        }
        if (string.IsNullOrEmpty(password))
        {
            return "";
        }
        using (DES des = DES.Create())
        {
            byte[] bytes = Encoding.Default.GetBytes(password);
            des.Key = Encoding.ASCII.GetBytes(key);
            des.IV = Encoding.ASCII.GetBytes(key);
            using (MemoryStream memoryStream = new MemoryStream())
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, des.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cryptoStream.Write(bytes, 0, bytes.Length);
                    cryptoStream.FlushFinalBlock();
                    StringBuilder stringBuilder = new StringBuilder();
                    byte[] array = memoryStream.ToArray();
                    foreach (byte b in array)
                    {
                        stringBuilder.AppendFormat("{0:X2}", b);
                    }
                    return stringBuilder.ToString();
                }
            }
        }
    }

    public static string Decrypt(string password, string key)
    {
        if (key.Length != 8)
        {
            return "";
        }
        if (string.IsNullOrEmpty(password))
        {
            return "";
        }

        using (DES des = DES.Create())
        {
            byte[] array = new byte[password.Length / 2];
            for (int i = 0; i < password.Length / 2; i++)
            {
                int num = Convert.ToInt32(password.Substring(i * 2, 2), 16);
                array[i] = (byte)num;
            }

            des.Key = Encoding.ASCII.GetBytes(key);
            des.IV = Encoding.ASCII.GetBytes(key);
            using (MemoryStream memoryStream = new MemoryStream())
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, des.CreateDecryptor(), CryptoStreamMode.Write))
                {
                    cryptoStream.Write(array, 0, array.Length);
                    cryptoStream.FlushFinalBlock();
                    return Encoding.Default.GetString(memoryStream.ToArray());
                }
            }
        }
    }
}