using System;

using System.Text;

using System.Security.Cryptography;

using System.IO;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(DecryptData("5CE1E516D6D5B215", "0123456789abcdef"));

    }

    public static byte[] HexStringToByteArray(String hex)

        {

        int NumberChars = hex.Length;

        byte[] bytes = new byte[NumberChars / 2];

        for (int i = 0; i < NumberChars; i += 2) {

        bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);

        }

        return bytes;

        }

        // Convers a byte array to a HEX string

        public static string ByteArrayToHexString(byte[] bytes)

        {

        StringBuilder hexString = new StringBuilder(bytes.Length * 2);

        for (int i = 0; i < bytes.Length; i++)

        {

        hexString.Append(bytes[i].ToString("X2"));

        }

        return hexString.ToString();

        }

        public static string DecryptData(string strData, string strKey)

        {

            byte[] key = { };// Key   

            byte[] IV = { 10, 20, 30, 40, 50, 60, 70, 80 };

​

            try

            {

                key = HexStringToByteArray(strKey);

                Console.WriteLine(key.Length);

                DESCryptoServiceProvider ObjDES = new DESCryptoServiceProvider();

                ObjDES.Padding = PaddingMode.None;

               var inputByteArray = HexStringToByteArray(strData);

​

                MemoryStream Objmst = new MemoryStream();

                CryptoStream Objcs = new CryptoStream(Objmst, ObjDES.CreateDecryptor(key, key), CryptoStreamMode.Write);

                Objcs.Write(inputByteArray, 0, inputByteArray.Length);

                Objcs.FlushFinalBlock();

​

                Encoding encoding = Encoding.UTF8;

                  var x= ByteArrayToHexString(Objmst.ToArray());

            var y = ASCIIEncoding.ASCII.GetString(Objmst.ToArray());

            var z = ASCIIEncoding.UTF8.GetString(Objmst.ToArray());

            var ddz = Encoding.UTF8.GetString(Objmst.ToArray());

                Console.WriteLine(x,y,z,ddz);

                return ByteArrayToHexString(Objmst.ToArray());

            }

            catch (System.Exception ex)

            {

                throw ex;

            }

        }

}