[Python-Dev] Pickle alternative in stdlib (Was: On breaking modules into packages)

Fri Nov 5 01:21:41 CET 2010

Am 04.11.2010 17:15, schrieb anatoly techtonik:
 > pickle is insecure, marshal too.
If the transport or storage layer is not save, you should 
cryptographically sign the data anyway::
 def pickle_encode(data, key):
 msg = base64.b64encode(pickle.dumps(data, -1))
 sig = base64.b64encode(hmac.new(key, msg).digest())
 return sig + ':' + msg
 def pickle_decode(data, key):
 if data and ':' in data:
 sig, msg = data.split(':', 1)
 if sig == base64.b64encode(hmac.new(key, msg).digest()):
 return pickle.loads(base64.b64decode(msg))
 raise pickle.UnpicklingError("Wrong or missing signature.")
Bottle (a web framework) uses a similar approach to store non-string 
data in client-side cookies. I don't see a (security) problem here.
-- 
Mit freundlichen Grüßen
Marcel Hellkamp