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Convert String to Dictionary question

Martin v. Loewis martin at v.loewis.de
Tue Feb 26 04:01:34 EST 2002 
"Jason Orendorff" <jason at jorendorff.com> writes:

> For what it's worth, *this* particular hole seems to have been
> patched.  But pickle can still call class constructors and
> __setstate__ methods and so forth, and it seems to me that
> plenty of standard lib constructors do at least a little disk
> access and socket stuff.  So it's still not safe.

If you want to restrict it to allow only restauration of a selected
number of classes, you need to perform unpickling in a restricted
environment. There you have explicit control over what builtins are
available; 

import rexec, pickle

l = pickle.dumps(["1",2,3])

class RExec(rexec.RExec):
  ok_builtin_modules = rexec.RExec.ok_builtin_modules + ('cPickle',)

r=RExec()
r.r_exec("import cPickle")
print r.r_eval("cPickle.loads(%s)" % repr(l))

works fine for me.

Regards,
Martin
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