app/django/contrib/formtools/utils.py

   1 try:
   2     import cPickle as pickle
   3 except ImportError:
   4     import pickle
   5
   6 from django.conf import settings
   7 from django.utils.hashcompat import md5_constructor
   8 from django.forms import BooleanField
   9
  10 def security_hash(request, form, *args):
  11     """
  12     Calculates a security hash for the given Form instance.
  13
  14     This creates a list of the form field names/values in a deterministic
  15     order, pickles the result with the SECRET_KEY setting, then takes an md5
  16     hash of that.
  17     """
  18
  19     data = [(bf.name, bf.field.clean(bf.data) or '') for bf in form]
  20     data.extend(args)
  21     data.append(settings.SECRET_KEY)
  22
  23     # Use HIGHEST_PROTOCOL because it's the most efficient. It requires
  24     # Python 2.3, but Django requires 2.3 anyway, so that's OK.
  25     pickled = pickle.dumps(data, pickle.HIGHEST_PROTOCOL)
  26
  27     return md5_constructor(pickled).hexdigest()
  28