private static string decryptString(string source)
{
var result = source;
if (!string.IsNullOrEmpty(source))
{
var sourceBytes = Convert.FromBase64String(source);
var data = (new SHA256Managed()).ComputeHash(Encoding.UTF8.GetBytes(BaseString));
byte[] decryptionResult;
using (var ms = new MemoryStream(sourceBytes))
using (var alg = new RijndaelManaged())
{
alg.IV = data.Take(alg.BlockSize / 8).ToArray();
alg.Key = data.Take(32).ToArray();
using (var crstr = new CryptoStream(ms, alg.CreateDecryptor(), CryptoStreamMode.Read))
decryptionResult = crstr.AllBytes();
}
result = Encoding.UTF8.GetString(decryptionResult);
}
return(result);
}