05.01.12 21:14, Glenn Linderman написав(ла):
So, fixing the vulnerable packages could be a sufficient response,
rather than changing the hash function. How to fix? Each of those
above allocates and returns a dict. Simply have each of those allocate
and return and wrapped dict, which has the following behaviors:
i) during __init__, create a local, random, string.
ii) for all key values, prepend the string, before passing it to the
internal dict.
Good idea.
# -*- coding: utf-8 -*-
from collections import MutableMapping
import random
class SafeDict(dict, MutableMapping):
def __init__(self, *args, **kwds):
dict.__init__(self)
self._prefix = str(random.getrandbits(64))
self.update(*args, **kwds)
def clear(self):
dict.clear(self)
self._prefix = str(random.getrandbits(64))
def _safe_key(self, key):
return self._prefix + repr(key), key
def __getitem__(self, key):
try:
return dict.__getitem__(self, self._safe_key(key))
except KeyError as e:
e.args = (key,)
raise e
def __setitem__(self, key, value):
dict.__setitem__(self, self._safe_key(key), value)
def __delitem__(self, key):
try:
dict.__delitem__(self, self._safe_key(key))
except KeyError as e:
e.args = (key,)
raise e
def __iter__(self):
for skey, key in dict.__iter__(self):
yield key
def __contains__(self, key):
return dict.__contains__(self, self._safe_key(key))
setdefault = MutableMapping.setdefault
update = MutableMapping.update
pop = MutableMapping.pop
popitem = MutableMapping.popitem
keys = MutableMapping.keys
values = MutableMapping.values
items = MutableMapping.items
def __repr__(self):
return '{%s}' % ', '.join('%s: %s' % (repr(k), repr(v))
for k, v in self.items())
def copy(self):
return self.__class__(self)
@classmethod
def fromkeys(cls, iterable, value=None):
d = cls()
for key in iterable:
d[key] = value
return d
def __eq__(self, other):
return all(k in other and other[k] == v for k, v in self.items()) and \
all(k in self and self[k] == v for k, v in other.items())
def __ne__(self, other):
return not self == other
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