Address SF bug #577530: del __builtins__ breaks out of rexec
Using the suggestion there: add_module() forces __builtin__ back; this
fixes r_exec, r_eval, r_execfile.
This does not mean that rexec is now considered safe! But for those
willing to take the risk, it's safer than before. (Note that a safety
analysis of the code module would be wise if you plan to use the
interactive console for real -- I've only ever used it to play with
restricted mode.)
SF bug 533625 (Armin Rigo). rexec: potential security hole
If a rexec instance allows writing in the current directory (a common
thing to do), there's a way to execute bogus bytecode. Fix this by
not allowing imports from .pyc files (in a way that allows a site to
configure things so that .pyc files *are* allowed, if writing is not
allowed).
just by doing type(f) where f is any file object. This left a hole in
restricted execution mode that rexec.py can't plug by itself (although it
can plug part of it; the rest is plugged in fileobject.c now).
also modified check_all function to suppress all warnings since they aren't
relevant to what this test is doing (allows quiet checking of regsub, for
instance)
(2) Made the test script a bit fancier -- you can now use it to run
arbitrary scripts in restricted mode, and it will do the right thing.
(The interactive mode is still pretty lame; should integrate this with
code.interact().)
unmarshalling code is actually rather naive and can easily be
caused to crash by feeding it invalid data. This should be fixed in
the marshal module, but I don't have the time to fix it now :-(
