using System;
using System.Security.Cryptography;

public class Test
{
    public static void Main()
	{            
		Console.WriteLine(EncryptString("test", "123456"));
	}
    
    public static string EncryptString(string Message, string Passphrase)
    {
        byte[] Results;
        System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();

        // Step 1. We hash the passphrase using MD5
        // We use the MD5 hash generator as the result is a 128 bit byte array
        // which is a valid length for the TripleDES encoder we use below
    
        SHA256CryptoServiceProvider HashProvider = new SHA256CryptoServiceProvider();
        byte[] temp = HashProvider.ComputeHash(UTF8.GetBytes(Passphrase));
        byte[] key = new byte[24];
        Array.Copy(temp, key, 24);
        
        // Step 2. Create a new RijndaelManaged object
        TripleDESCryptoServiceProvider crypt = new TripleDESCryptoServiceProvider();
    
        // Step 3. Setup the encoder
        crypt.Key = key;
        crypt.Mode = CipherMode.ECB;
        crypt.Padding = PaddingMode.PKCS7;
    
        // Step 4. Convert the input string to a byte[]
        byte[] DataToEncrypt = UTF8.GetBytes(Message);
        
        //Console.WriteLine( Convert.ToBase64String(DataToEncrypt));
    
        ICryptoTransform cTransform = crypt.CreateEncryptor();

        // Step 5. Attempt to encrypt the string
        try
        {
            ICryptoTransform Encryptor = crypt.CreateEncryptor();
            Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length);
        }
        finally
        {
            // Clear the crypt and Hashprovider services of any sensitive information
            crypt.Clear();
            HashProvider.Clear();
        }
    
        // Step 6. Return the encrypted string as a base64 encoded string
        return Convert.ToBase64String(Results);
    }
}