using System;

using System.Text;

using System.Security.Cryptography;

using System.IO;

​

public class Program

{

    public void Main()

    {

        /***********************************************************/

        /* Declare a new instance of AES with the secret key       */

        /***********************************************************/

        AES aes = new AES("TEST");        //                       */

        /***********************************************************/

        /* To encrypt a message, call the Encrypt() function from  */

        /* the instance with the desired message as the parameter. */

        /***********************************************************/

        string e = aes.Encrypt("Worked!");//                       */

        /***********************************************************/

        /* To decrypt a message, call the Decrypt() function from  */

        /* the instance with the desired message as the parameter. */

        /***********************************************************/

        string d = aes.Decrypt(e);

        Console.WriteLine("Encrypted: " + e);

        Console.WriteLine("Decrypted: " + d);

        Console.WriteLine();

        Console.WriteLine("The whole source can be found on https://github.com/halitalf/cross-aes");

    }

​

    public class AES

    {

        private byte[] key;

        public AES(string SecretKey)

        {

            string k = Pass2Key(SecretKey);

            Console.WriteLine("Key:       " + k);

            key = Encoding.UTF8.GetBytes(k);

        }

​

        public string Encrypt(string plainText)

        {

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

            {

                throw new ArgumentNullException("plainText");

            }

​

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

            {

                throw new ArgumentNullException("key");

            }

​

            byte[] encrypted;

            using (var rijAlg = new RijndaelManaged())

            {

                rijAlg.BlockSize = 256;

                rijAlg.Key = key;

                rijAlg.Mode = CipherMode.CBC;

                rijAlg.Padding = PaddingMode.Zeros;

                rijAlg.IV = key;

                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                using (var msEncrypt = new MemoryStream())

                {

                    using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))

                    {

                        using (var swEncrypt = new StreamWriter(csEncrypt))

                        {

                            swEncrypt.Write(plainText);

                        }

​

                        encrypted = msEncrypt.ToArray();

                    }

                }

            }

​

            return System.Convert.ToBase64String(encrypted);

        }

​

        public string Decrypt(string encrypted)

        {

            byte[] cipherText = System.Convert.FromBase64String(encrypted);

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

            {

                throw new ArgumentNullException("cipherText");

            }

​

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

            {

                throw new ArgumentNullException("key");

            }

​

            string plaintext;

            using (var rijAlg = new RijndaelManaged())

            {

                rijAlg.BlockSize = 256;

                rijAlg.Key = key;

                rijAlg.Mode = CipherMode.CBC;

                rijAlg.Padding = PaddingMode.Zeros;

                rijAlg.IV = key;

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

                using (var msDecrypt = new MemoryStream(cipherText))

                {

                    using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))

                    {

                        using (var srDecrypt = new StreamReader(csDecrypt))

                        {

                            plaintext = srDecrypt.ReadToEnd();

                        }

                    }

                }

            }

​

            return plaintext;

        }

​

        public string Pass2Key(string SecretKey)

        {

            return System.Convert.ToBase64String((new SHA512CryptoServiceProvider()).ComputeHash(Encoding.UTF8.GetBytes(SecretKey))).Substring(0, 32);

        }

    }

}