[Python-Dev] Reviving restricted mode?

[P.J. Eby]

At 08:45 AM 2/22/2009 -0800, Guido van Rossum wrote:
>I've received some enthusiastic emails from someone who wants to
>revive restricted mode. He started out with a bunch of patches to the
>CPython runtime using ctypes, which he attached to an App Engine bug:
>
>http://code.google.com/p/googleappengine/issues/detail?id=671
>
>Based on his code (the file secure.py is all you need, included in
>secure.tar.gz) it seems he believes the only security leaks are
>__subclasses__, gi_frame and gi_code. (I have since convinced him that
>if we add "restricted" guards to these attributes, he doesn't need the
>functions added to sys.)
>
>I don't recall the exploits that Samuele once posted that caused the
>death of rexec.py -- does anyone recall, or have a pointer to the
>threads?

Just a question, but, if you just need a pure-python restricted 
environment for App Engine, why not just use the RestrictedPython 
package (i.e., http://pypi.python.org/pypi/RestrictedPython )?