private static extern int BCryptRemoveContextFunction(ConfigurationTable dwTable, string pszContext, CryptographicInterface dwInterface, string pszFunction);
 private static extern int BCryptEnumContextFunctions(ConfigurationTable dwTable, string pszContext, CryptographicInterface dwInterface, ref uint pcbBuffer, out IntPtr ppBuffer);
 private static extern int BCryptAddContextFunction(ConfigurationTable dwTable, string pszContext, CryptographicInterface dwInterface, string pszFunction, FunctionPosition dwPosition);