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

[Marcel Hellkamp]

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