using System;

using System.Text;

using System.IO;

using System.Security.Cryptography;

using LZStringCSharp;

​

public class Program

{

    public static void Main()

    {

        string original = "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";

        string pw = "";

​

                Console.WriteLine("Round Trip: {0}", LZString.DecompressFromEncodedURIComponent(Decrypt(pw, original)));

        //LZString.DecompressFromEncodedURIComponent(Decrypt(pw, original));

    }

​

    private static byte[][] GetHashKeys(string key)

    {

        byte[][] result = new byte[2][];

        Encoding enc = Encoding.UTF8;

        SHA256 sha2 = new SHA256CryptoServiceProvider();

        byte[] rawKey = enc.GetBytes(key);

        byte[] rawIV = enc.GetBytes(key);

        byte[] hashKey = sha2.ComputeHash(rawKey);

        byte[] hashIV = sha2.ComputeHash(rawIV);

        Array.Resize(ref hashIV, 16);

        result[0] = hashKey;

        result[1] = hashIV;

        return result;

    }

​

    public static string Decrypt(string key, string data)

    {

        string decData = null;

        byte[][] keys = GetHashKeys(key);

​

​

        try

        {

            decData = DecryptStringFromBytes_Aes(data, keys[0], keys[1]);

        }

        catch (CryptographicException e) {      

        }

        catch (ArgumentNullException) { 

        }

​

        return decData;

    }

​

    private static string DecryptStringFromBytes_Aes(string cipherTextString, byte[] Key, byte[] IV)

    {

        byte[] cipherText = Convert.FromBase64String(cipherTextString);

​

        if (cipherText == null || cipherText.Length <= 0)

            throw new ArgumentNullException("cipherText");

        if (Key == null || Key.Length <= 0)

            throw new ArgumentNullException("Key");

        if (IV == null || IV.Length <= 0)

            throw new ArgumentNullException("IV");

​

        string plaintext = null;

​

        using (Aes aesAlg = Aes.Create())

        {

            aesAlg.Key = Key;

            aesAlg.IV = IV;

​

            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

​

            using (MemoryStream msDecrypt = new MemoryStream(cipherText))

            {

                using (CryptoStream csDecrypt =

                        new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))

                {

                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))

                    {

                        plaintext = srDecrypt.ReadToEnd();

                    }

                }

            }

        }

        return plaintext;

    }

}