From: Dalibor Sramek <dali@...>
Date: 2003-01-10T23:49:30+09:00
Subject: Re: Security problems

On Fri, Jan 10, 2003 at 05:42:11PM +0900, Tim Bates wrote:
> Can anyone else see a way around this? Running the code in a separate process 
> (like RealTimeBattle does) is not really an option either, because it would 
> still allow malicious code to damage the system on which it is run, and it 
> would reduce the ability run tournaments etc safely.

I would still argue for separate processes and the client/server model.
What you are trying to do is exactly separating a robot controlling code
from the world controlling code.
If your server implements the hardware part of robots with a well defined
interface and the software part is left for clients then every robot writer
can change the world status only via the virtual hardware provided by the
server.

Why do you think that separate processes would break the security?

What I imagine is something like this:

Server:
class Robot

  def turnLeft(howmuch)
    check_and_do_something
  end

  ..etc

end

Server accepts connection and for every connection makes an instance of the
Robot class (the connection is connected to the class).
When the server gets "turnLeft(34)" from the connection it can translate it
to appropriate_instance.turnLeft(34).
In other words the client can use just a defined set of methods.

Client
There are many ways to write a client for the described server.


Anyway I hope that you work on the robot game will quickly lead to some
interesting battles.

Regards,

Dalibor Sramek

-- 
Dalibor Sramek  http://www.insula.cz/dali  |  In the eyes of cats,
                dalibor.sramek@insula.cz   |  all things belong to cats.