[pypy-dev] Running untrusted code in pypy

[holger krekel]

Hi Vinj, 

On Mon, Feb 19, 2007 at 08:05 -0800, Vinj Vinj wrote:
> I've been following pypy dev for several years and
> this is my first post here. Thanks for all the hard
> work you guys have put in, it is truly exciting to see
> what pypy has accomplished so far. 
> 
> I'm currently building a distributing financial
> trading application that allows users to write trading
> models in python and lua. I had to introduce lua,
> since there is no way to completely "secure" user
> models written in cPython. 
> 
> I'm working with a modified Lua core which allows me
> to restrict the max memory and max CPU cycles
> available for each vm. I then have a python-lua bridge
> code that allows you exchange data and function calls
> between the two. 
> 
> Would I be able to do something similar with pypy?

PyPy does not (currently) aim at offering cpu/mem
restrictions, but you could use virtual hosts (XEN or vserver)
for that, both offer such restriction settings.  PyPy itself
may help with the Taint Object Space: 

http://codespeak.net/pypy/dist/pypy/doc/objspace-proxies.html#the-taint-object-space

to track sensitive data flows in your application and prevent
it from accidentally leaking. 

> Would I be able to ensure that no malicious user is
> able to bring my hosted application down?

I'd probably use kernel-level security for that, maybe
in combination with VM provided features. (not sure
if you refer to processing of user-input or to 
DOS attacks or some other security aspects, it
obviously all depends a bit on concrete use cases
and intentions). 
 
> Are any of you guys going to be at pycon-2007?

Michael and Christian are going to be there,
myself i am busy preparing for the upcoming sprints, 
but i am happy to discuss possibilities some time. 

best, 

holger

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