/// <summary>
/// Decrypts the data.
/// </summary>
/// <param name="value">The value.</param>
/// <param name="context">The context.</param>
/// <returns>
/// The <see cref="T:byte[]"/>.
/// </returns>
private byte[] Unprotect(string value, HttpContextBase context)
{
if (string.IsNullOrWhiteSpace(value))
{
return(null);
}
string prefix = value[0].ToString();
string purpose = this.GetMachineKeyPurposeFromPrefix(prefix, context);
if (purpose == null)
{
return(null);
}
value = value.Substring(1);
byte[] bytes = Convert.FromBase64String(value);
try
{
return(MachineKey.Unprotect(bytes, purpose));
}
catch (CryptographicException ex)
{
ValidationException?.Invoke(this, ex);
return(null);
}
}
