Private variables

[Timothy J. Wood]

On Friday, October 18, 2002, at 07:14  PM, Erik Max Francis wrote:
> This isn't really a security issue unless people can dynamically 
> install
> Python scripts that execute on _other_ peoples' machines.  Having a
> scriptable engine doesn't mean that the scripts need to have security
> protections in place, unless that engine will be running in some
> entrusted location and untrusted scripts are what you plan to run.

   As a script writer you will be able to make scripts available for 
people to download -- but you won't be able to 'dynamically install' 
them on someone else's machine.  But the distinction is moot, really, 
since most game players will be ignorant of the security implications 
of various constructs and shouldn't be expected to do a security audit 
of some code to play a new game type.

> If that is the case, then Python is really not a good choice; but then,
> very few languages would be suitable.  Even security conscious 
> languages
> usually can't protect you from mundane, malicious attacks, such as busy
> wait loops, or allocating objects to fill up memory, or spawning
> processes/threads to fill up process tables.

   Sure -- all the resource-based DoS problems will still exist, but 
these at least don't corrupt or expose any of the user's information.  
They can kill the application, uninstall that game type and never play 
it again.

   I've also looked at Ruby a bit, but was put off by the relative 
immaturity of their implementation, GC, and such.  Perl seems a little 
too big to be a suitable option.  Java would be nice security-wise, but 
the GC issues probably would probably make it unsuitable.  I've not 
looked at Lua in much detail, but what I did see didn't please me too 
much.

   Really, I want the Ruby language, with some of Python's 
implementation maturity and Java's security model.  Clearly, I'm going 
to be disappointed :), but I'm willing to do some work to make Python 
do what I want (and hopefully this will help someone else out in the 
future).

-tim