AES Crypto

    public class AesCrypto<T> : ICrypto<T>
    {
        string DecryptionKey { get { return ((MachineKeySection)ConfigurationManager.GetSection("system.web/machineKey")).DecryptionKey } }
        string ValidationKey { get { return ((MachineKeySection)ConfigurationManager.GetSection("system.web/machineKey")).ValidationKey } }

        RijndaelManaged aesAlg;
        ICryptoTransform encryptor;
        ICryptoTransform decryptor;

        public AesCrypto()
        {
            // generate the key from the shared secret and the salt
            var key = new Rfc2898DeriveBytes(DecryptionKey, ASCIIEncoding.ASCII.GetBytes(ValidationKey));

            // Create a RijndaelManaged object
            var aesAlg = new RijndaelManaged();
            aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);

            // Create a encryptor and decryptor to perform the stream transform.
            encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
            decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
        }

        public string Encrypt(T source)
        {
            var sourceString = JsonConvert.SerializeObject(source);
            
            // Create the streams used for encryption.
            using (var msEncrypt = new MemoryStream())
            {
                // prepend the IV
                msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
                msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
                using (var cryptoWriter = new StreamWriter(new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)))
                {
                    cryptoWriter.Write(sourceString);
                    return Convert.ToBase64String(msEncrypt.ToArray());
                }
            }
        }

        public T Decrypt(string sourceString)
        {
            // Create the streams used for encryption.
            using (var msDecrypt = new MemoryStream())
            {
                // prepend the IV
                msDecrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
                msDecrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
                using (var cryptoWriter = new StreamWriter(new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Write)))
                {
                    cryptoWriter.Write(sourceString);
                    return JsonConvert.DeserializeObject<T>(Convert.ToBase64String(msDecrypt.ToArray()));
                }
            }
        }
    }