I like the way Brian just sent before. I dont know any language that
restricts its usage (would be neat feature for certain projects).
Perl has "taint mode". When enabled, Perl won't let you do any
"dangerous" operations (file accesses, system calls, etc) on data that
originally came from the user and hasn't been processed to remove its
"taintedness".
On the other hand, allowing people to run arbitrary code on your
machine is a Bad Idea even if you *can* ensure that the filesystem
isn't touched. What if they send any of the following?
while True:
pass
def fib(n):
return fib(n-1) + fib(n-2)
fib(1000000)
def steal_data():
send_to_client("127.0.0.1", pickle.dump(confidential.data.structure)
There are just so many ways to exploit arbitrary code execution, from
malicious data corruption to denial-of-service to buffer-overflow
exploits (yes, this is possible even from within Python, if you use
any buggy C extension modules)... it's *really* not a good idea. A
lot of very smart people have worked hard to solve this sort of
problem, and not made much progress.
I either recommend having an explicit server/client API and forcing
people to use that API (whether it's invoked via Perspective Broker as
I suggested earlier, or something more standard like XML-RPC, CORBA,
or SOAP), or not allowing a "scripting language" at all, instead
opting for something like customizable configuration files that aren't
Turing-complete.
