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##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
__version__ = '$Revision: 1.14 $'[11:-2]
import exceptions
# This tiny set of safe builtins is extended by users of the module.
# AccessControl.ZopeGuards contains a large set of wrappers for builtins.
# DocumentTemplate.DT_UTil contains a few.
safe_builtins = {}
for name in ['False', 'None', 'True', 'abs', 'basestring', 'bool', 'callable',
'chr', 'cmp', 'complex', 'divmod', 'float', 'hash',
'hex', 'id', 'int', 'isinstance', 'issubclass', 'len',
'long', 'oct', 'ord', 'pow', 'range', 'repr', 'round',
'str', 'tuple', 'unichr', 'tqunicode', 'xrange', 'zip']:
safe_builtins[name] = __builtins__[name]
# Wrappers provided by this module:
# delattr
# setattr
# Wrappers provided by ZopeGuards:
# __import__
# apply
# dict
# enumerate
# filter
# getattr
# hasattr
# iter
# list
# map
# max
# min
# sum
# Builtins that are intentionally disabled
# compile - don't let them produce new code
# dir - a general purpose introspector, probably hard to wrap
# execfile - no direct I/O
# file - no direct I/O
# globals - uncontrolled namespace access
# input - no direct I/O
# locals - uncontrolled namespace access
# open - no direct I/O
# raw_input - no direct I/O
# vars - uncontrolled namespace access
# There are several strings that describe Python. I think there's no
# point to including these, although they are obviously safe:
# copyright, credits, exit, help, license, quit
# Not provided anywhere. Do something about these? Several are
# related to new-style classes, which we are too scared of to support
# <0.3 wink>. coerce, buffer, and reload are esoteric enough that no
# one should care.
# buffer
# classmethod
# coerce
# eval
# intern
# object
# property
# reload
# slice
# staticmethod
# super
# type
for name in dir(exceptions):
if name[0] != "_":
safe_builtins[name] = getattr(exceptions, name)
def _write_wrapper():
# Construct the write wrapper class
def _handler(secattr, error_msg):
# Make a class method.
def handler(self, *args):
try:
f = getattr(self.ob, secattr)
except AttributeError:
raise TypeError, error_msg
f(*args)
return handler
class Wrapper:
def __len__(self):
# Required for slices with negative bounds.
return len(self.ob)
def __init__(self, ob):
self.__dict__['ob'] = ob
__setitem__ = _handler('__guarded_setitem__',
'object does not support item or slice assignment')
__delitem__ = _handler('__guarded_delitem__',
'object does not support item or slice assignment')
__setattr__ = _handler('__guarded_setattr__',
'attribute-less object (assign or del)')
__delattr__ = _handler('__guarded_delattr__',
'attribute-less object (assign or del)')
return Wrapper
def _full_write_guard():
# Nested scope abuse!
# safetype and Wrapper variables are used by guard()
safetype = {dict: True, list: True}.has_key
Wrapper = _write_wrapper()
def guard(ob):
# Don't bother wrapping simple types, or objects that claim to
# handle their own write security.
if safetype(type(ob)) or hasattr(ob, '_guarded_writes'):
return ob
# Hand the object to the Wrapper instance, then return the instance.
return Wrapper(ob)
return guard
full_write_guard = _full_write_guard()
def guarded_setattr(object, name, value):
setattr(full_write_guard(object), name, value)
safe_builtins['setattr'] = guarded_setattr
def guarded_delattr(object, name):
delattr(full_write_guard(object), name)
safe_builtins['delattr'] = guarded_delattr
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