Как работают InteropPermission и fileIOPermission?

[Lankey]

Для наглядности, вот код WinAPIServer::getTempPath()

#define.maxPath(260)
public server static str getTempPath()
{
    FileIOPermission fileIOPerm;
    InteropPermission interopPerm;
    str tempPath;
     // check file I/O permission
    fileIOPerm = new FileIOPermission('','r');
    fileIOPerm.demand();
    // get dll interop permission
    interopPerm = new InteropPermission(InteropKind::ClrInterop);
    interopPerm.assert();
    tempPath = System.IO.Path::GetTempPath();
    CodeAccessPermission::revertAssert();
    return tempPath;
}