using System;

using System.Security.Cryptography;

using System.Text;

public class Program

{

    public static void Main()

    {

        String data = "This is a data which I would like to encrypt with AES128 CBC and should ok and fast.. Perhaps.."; // 95 length

        String password = "123456";

        String iv = "just random. #@$#@R ERTEWGREGEWg";

        byte[] dataBytes = Encoding.ASCII.GetBytes(data);

        byte[] passwordBytes = MD5_password(password);

        byte[] ivBytes = MD5_password(iv);

​

        Console.WriteLine("Data: {0}", byte_array_to_hex(dataBytes));

        Console.WriteLine("Key: {0}", byte_array_to_hex(passwordBytes));

        Console.WriteLine("IV: {0}", byte_array_to_hex(ivBytes));

        Console.WriteLine(byte_array_to_hex(AES_encrypt_cbc(dataBytes, passwordBytes, ivBytes)));

    }

​

    public static string byte_array_to_hex(byte[] bytes)

    {

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

        foreach (byte b in bytes)

            hex.AppendFormat("{0:x2}", b);

        return hex.ToString();

    }

    private static byte[] MD5_password(String password)

    {

        using (MD5 md5 = MD5.Create())

            return md5.ComputeHash(Encoding.ASCII.GetBytes(password));

    }

    private static byte[] AES_encrypt_cbc(byte[] plaintext, byte[] key, byte[] iv)

    {

        int reminder = plaintext.Length % 16;

        int padding = (reminder != 0 ? 16 - reminder : 16);

        byte[] ciphertext = new byte[plaintext.Length + padding];

        int i = 0;

        for (; i < plaintext.Length - reminder; i += 16)

        {

            XOR_byte_block(iv, 0, plaintext, i, ciphertext, i);

            AES_encrypt_block(ciphertext, i, key, iv, 0);

            Array.Copy(iv, 0, ciphertext, i, 16);

        }

​

        if (reminder != 0)

            Array.Copy(plaintext, i, ciphertext, i, reminder);

        for (int p = plaintext.Length; p < ciphertext.Length; ++p)

            ciphertext[p] = (byte) padding;

​

        XOR_byte_block(iv, 0, ciphertext, i, ciphertext, i);

        AES_encrypt_block(ciphertext, i, key, iv, 0);

        Array.Copy(iv, 0, ciphertext, i, 16);

        return ciphertext;

    }

    private static void XOR_byte_block(byte[] a, int aofs, byte[] b, int bofs, byte[] dest, int destofs)

    {

        for (int i = 0; i < 16; ++i)

            dest[destofs + i] = (byte) (a[aofs + i] ^ b[bofs + i]);

    }

​

    private static void AES_encrypt_block(byte[] plaintext, int plainofs, byte[] key, byte[] ciphertext, int cipherofs)

    {

        using (AesManaged aes = new AesManaged())

        {

            aes.Mode = CipherMode.ECB;

            aes.BlockSize = 128;

            aes.KeySize = key.Length * 8;

            aes.Padding = PaddingMode.None;

            aes.Key = key;

            ICryptoTransform enc = aes.CreateEncryptor(aes.Key, aes.IV);

            enc.TransformBlock(plaintext, plainofs, 16, ciphertext, cipherofs);

        }

    }

​

    /*

    private static byte[] AES_Decrypt_block(byte[] cipherText, byte[] Key)

    {

        byte[] output_buffer = new byte[cipherText.Length];

​

        using (AesManaged aesAlg = new AesManaged())

        {

            aesAlg.Mode = CipherMode.ECB;

​

            aesAlg.BlockSize = 128;

            aesAlg.KeySize = 128;

            aesAlg.Padding = PaddingMode.None;

            aesAlg.Key = Key;

​

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

            decryptor.TransformBlock(cipherText, 0, cipherText.Length, output_buffer, 0);

        }

​

        return output_buffer;

    }

    */

}