apps/piston/forms.py

   1 import hmac, base64
   2
   3 from django import forms
   4 from django.conf import settings
   5
   6 class Form(forms.Form):
   7     pass
   8
   9 class ModelForm(forms.ModelForm):
  10     """
  11     Subclass of `forms.ModelForm` which makes sure
  12     that the initial values are present in the form
  13     data, so you don't have to send all old values
  14     for the form to actually validate. Django does not
  15     do this on its own, which is really annoying.
  16     """
  17     def merge_from_initial(self):
  18         self.data._mutable = True
  19         filt = lambda v: v not in self.data.keys()
  20         for field in filter(filt, getattr(self.Meta, 'fields', ())):
  21             self.data[field] = self.initial.get(field, None)
  22
  23
  24 class OAuthAuthenticationForm(forms.Form):
  25     oauth_token = forms.CharField(widget=forms.HiddenInput)
  26     oauth_callback = forms.CharField(widget=forms.HiddenInput, required=False)
  27     authorize_access = forms.BooleanField(required=True)
  28     csrf_signature = forms.CharField(widget=forms.HiddenInput)
  29
  30     def __init__(self, *args, **kwargs):
  31         forms.Form.__init__(self, *args, **kwargs)
  32
  33         self.fields['csrf_signature'].initial = self.initial_csrf_signature
  34
  35     def clean_csrf_signature(self):
  36         sig = self.cleaned_data['csrf_signature']
  37         token = self.cleaned_data['oauth_token']
  38
  39         sig1 = OAuthAuthenticationForm.get_csrf_signature(settings.SECRET_KEY, token)
  40
  41         if sig != sig1:
  42             raise forms.ValidationError("CSRF signature is not valid")
  43
  44         return sig
  45
  46     def initial_csrf_signature(self):
  47         token = self.initial['oauth_token']
  48         return OAuthAuthenticationForm.get_csrf_signature(settings.SECRET_KEY, token)
  49
  50     @staticmethod
  51     def get_csrf_signature(key, token):
  52         # Check signature...
  53         try:
  54             import hashlib # 2.5
  55             hashed = hmac.new(key, token, hashlib.sha1)
  56         except:
  57             import sha # deprecated
  58             hashed = hmac.new(key, token, sha)
  59
  60         # calculate the digest base 64
  61         return base64.b64encode(hashed.digest())
  62