AES decryption

Crypto.cs

using System;
using System.Text;
using System.Security.Cryptography;

/**

    USO:

    Crypto c = new Crypto(null);
    string rawToken = c.DecryptFromBase64(token);
    

**/
namespace biometrika
{
    public class Crypto
    {
        private ICryptoTransform rijndaelDecryptor;

        private static byte[] rawSecretKey = {0x24, 0xed, 0xf3, 0x75,
            0x97, 0xa4, 0x6b, 0xed, 0xa1, 0x90,
            0x97, 0x5b, 0xb6, 0x2e, 0xcf, 0x70};

        public Crypto(string passphrase)
        {
            if (passphrase == null) {
                passphrase = "--__b10m3tr1k4__--";
            }
            byte[] passwordKey = encodeDigest(passphrase);
            RijndaelManaged rijndael = new RijndaelManaged();
            rijndaelDecryptor = rijndael.CreateDecryptor(passwordKey, rawSecretKey);
        }

        public string Decrypt(byte[] encryptedData)
        {
            byte[] newClearData = rijndaelDecryptor.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
            return Encoding.ASCII.GetString(newClearData);
        }

        public string DecryptFromBase64(string encryptedBase64)
        {
            return Decrypt(Convert.FromBase64String(encryptedBase64));
        }

        private byte[] encodeDigest(string text)
        {
            MD5CryptoServiceProvider x = new System.Security.Cryptography.MD5CryptoServiceProvider();
            byte[] data = Encoding.ASCII.GetBytes(text);
            return x.ComputeHash(data);
        }
    }
}