From 7f7c3d0a9c401d7bc9a9d86ec7181cf09c4b3bab Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Sun, 15 Sep 2002 06:00:43 +0000 Subject: 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. The interactive console had to be fixed separately, because it doesn't use r_exec, but relies on the 'locals' dict having the right __builtins__. Fixed this by subclassing InteractiveConsole and overriding runcode(), which does the exec. This changes the banner output slightly: instead of starting with *** RESTRICTED ***, a subtler (RestrictedConsole) is printed before the first >>> prompt. Also import readline (if it exists) when the interactive console is used, for more convenient input editing and history. 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.) This should be backported to 2.2 and 2.1. --- Lib/rexec.py | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/Lib/rexec.py b/Lib/rexec.py index 674e193..081fe27 100644 --- a/Lib/rexec.py +++ b/Lib/rexec.py @@ -288,9 +288,9 @@ class RExec(ihooks._Verbose): # Add a module -- return an existing module or create one def add_module(self, mname): - if mname in self.modules: - return self.modules[mname] - self.modules[mname] = m = self.hooks.new_module(mname) + m = self.modules.get(mname) + if m is None: + self.modules[mname] = m = self.hooks.new_module(mname) m.__builtins__ = self.modules['__builtin__'] return m @@ -552,13 +552,17 @@ def test(): print "%s: can't open file %s" % (sys.argv[0], `args[0]`) return 1 if fp.isatty(): + try: + import readline + except ImportError: + pass import code + class RestrictedConsole(code.InteractiveConsole): + def runcode(self, co): + self.locals['__builtins__'] = r.modules['__builtin__'] + r.s_apply(code.InteractiveConsole.runcode, (self, co)) try: - code.interact( - "*** RESTRICTED *** Python %s on %s\n" - 'Type "help", "copyright", "credits" or "license" ' - "for more information." % (sys.version, sys.platform), - local=r.modules['__main__'].__dict__) + RestrictedConsole(r.modules['__main__'].__dict__).interact() except SystemExit, n: return n else: -- cgit v0.12