Secure Python

[Stephan Kuhagen]

timmy <"timothy at open-networks.net"> wrote:

This sub-thread starts to become a flame-war, isn't it? Calm down, both of
you... No need to fight, when only some ideas for a technical question are
requested.

> as posted before, linux kernel limit.
> 
> then you and your users can go as crazy as you want and you won't take
> out your system.

The problem with linux kernel limits are, that they won't work really good
on MacOSX and Windows... OTOH the idea is the right one, but the effect can
be achieved inside of Python. Since Python does byte compile the code and
the interpreter evaluates each byte code token in one evaluation step. The
interpreter could be extended for such usecases to count and limit the
number of evaluation steps allowed for untrusted script or methods in
untrusted script as well as to limit the recursion depth or memory to be
allocated. All those limits are managed by the interpreter for script code
and hence can be limited for untrusted code by the interpreter. This also
does not really make DoS impossible (what about C extensions? - maybe
restricting "import"?). - As I said before in this thread, making a sandbox
really secure is a hard job, and may need some serious changes in the
Python interpreter, but AFAIK from Tcl, it is possible - and would be nice
to have.

Regards
Stephan