I'm trying to get through the process of authenticating a Google token for accessing a user's calendar within a Django application. Although I've followed several indications found on the web, I'm stuck with a 400 error code response to my callback function (Bad Request).
views.py
# -*- coding: utf-8 -*-
import os
import argparse
import httplib2
import logging
from apiclient.discovery import build
from oauth2client import tools
from oauth2client.django_orm import Storage
from oauth2client import xsrfutil
from oauth2client.client import flow_from_clientsecrets
from django.http import HttpResponse
from django.http import HttpResponseBadRequest
from django.http import HttpResponseRedirect
from django.shortcuts import render_to_response
from django.core.urlresolvers import reverse
from django.contrib import auth
from django.contrib.auth.decorators import login_required
from django.conf import settings
from apps.tecnico.models import Credentials, Flow
CLIENT_SECRETS = os.path.join(
os.path.dirname(__file__), '../../client_secrets.json')
@login_required
def index(request):
storage = Storage(Credentials, 'id', request.user, 'credential')
FLOW = flow_from_clientsecrets(
CLIENT_SECRETS,
scope='https://www.googleapis.com/auth/calendar.readonly',
redirect_uri='http://MY_URL:8000/oauth2/oauth2callback'
)
credential = storage.get()
if credential is None or credential.invalid is True:
FLOW.params['state'] = xsrfutil.generate_token(
settings.SECRET_KEY, request.user)
authorize_url = FLOW.step1_get_authorize_url()
f = Flow(id=request.user, flow=FLOW)
f.save()
return HttpResponseRedirect(authorize_url)
else:
http = httplib2.Http()
http = credential.authorize(http)
service = build(serviceName='calendar', version='v3', http=http,
developerKey='MY_DEV_KEY_FROM_GOOGLE_CONSOLE')
events = service.events().list(calendarId='primary').execute()
return render_to_response('calendario/welcome.html', {
'events': events['items'],
})
@login_required
def auth_return(request):
if not xsrfutil.validate_token(
settings.SECRET_KEY, request.REQUEST['state'], request.user):
return HttpResponseBadRequest()
storage = Storage(Credentials, 'id', request.user, 'credential')
FLOW = Flow.objects.get(id=request.user).flow
credential = FLOW.step2_exchange(request.REQUEST)
storage.put(credential)
return HttpResponseRedirect("http://MY_URL:8000/caly")
models.py
from oauth2client.django_orm import FlowField, CredentialsField
[...]
class Credentials(models.Model):
id = models.ForeignKey(User, primary_key=True)
credential = CredentialsField()
class Flow(models.Model):
id = models.ForeignKey(User, primary_key=True)
flow = FlowField()
I've downloaded the client_secrets.json file directly from the Google Dev Console. The specified Client ID type in the Dev Console is "web application", which I think is correct. What I've noticed is, if I remove the token validation code block:
if not xsrfutil.validate_token(
settings.SECRET_KEY, request.REQUEST['state'], request.user):
return HttpResponseBadRequest()
everything works correctly, flow and credentials get correctly stored in the database and I'm allowed to read the calendar. What can I possibly be wrong with?
EDIT: I've also checked outgoing (to Google) and incoming (to callback) data:
OUTGOING:
request.user:
admin
settings.SECRET_KEY:
I_AM_NOT_WRITING_IT_HERE
FLOW.params['state']:
SOME_OTHER_RANDOM_STUFF
INCOMING:
request.user:
admin
settings.SECRET_KEY:
I_AM_NOT_WRITING_IT_HERE
FLOW.params['state']:
SOME_OTHER_RANDOM_STUFF
Data is identical, at least to a print to console. Also, the generation/validation operations via console work correctly (xsrfutil.validate_token returns True, both with test and real data, including User model instances). I'm even more puzzled.