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216 | # FacebookConnectMiddleware.py
from django.contrib.auth import authenticate, login, logout
from django.contrib.auth.models import User
from django.conf import settings
import md5
import urllib
import time
import simplejson
from datetime import datetime
# These values could be placed in Django's project settings
# More info here: http://nyquistrate.com/django/facebook-connect/
API_KEY = 'YOUR KEY FROM FACEBOOK'
API_SECRET = 'YOUR SECRET FROM FACEBOOK'
REST_SERVER = 'http://api.facebook.com/restserver.php'
# You can get your User ID here: http://developers.facebook.com/tools.php?api
MY_FACEBOOK_UID = 'YOUR FACEBOOK User ID'
NOT_FRIEND_ERROR = 'You must be my Facebook friend to log in.'
PROBLEM_ERROR = 'There was a problem. Try again later.'
ACCOUNT_DISABLED_ERROR = 'Your account is not active.'
ACCOUNT_PROBLEM_ERROR = 'There is a problem with your account.'
class FacebookConnectMiddleware(object):
delete_fb_cookies = False
facebook_user_is_authenticated = False
def process_request(self, request):
try:
# Set the facebook message to empty. This message can be used to dispaly info from the middleware on a Web page.
request.facebook_message = None
# Don't bother trying FB Connect login if the user is already logged in
if not request.user.is_authenticated():
# FB Connect will set a cookie with a key == FB App API Key if the user has been authenticated
if API_KEY in request.COOKIES:
signature_hash = self.get_facebook_signature(request.COOKIES, True)
# The hash of the values in the cookie to make sure they're not forged
if(signature_hash == request.COOKIES[API_KEY]):
# If session hasn't expired
if(datetime.fromtimestamp(float(request.COOKIES[API_KEY+'_expires'])) > datetime.now()):
# Make a request to FB REST(like) API to see if current user is my friend
are_friends_params = {
'method':'Friends.areFriends',
'api_key': API_KEY,
'session_key': request.COOKIES[API_KEY + '_session_key'],
'call_id': time.time(),
'v': '1.0',
'uids1': MY_FACEBOOK_UID,
'uids2': request.COOKIES[API_KEY + '_user'],
'format': 'json',
}
are_friends_hash = self.get_facebook_signature(are_friends_params)
are_friends_params['sig'] = are_friends_hash
are_friends_params = urllib.urlencode(are_friends_params)
are_friends_response = simplejson.load(urllib.urlopen(REST_SERVER, are_friends_params))
# If we are friends
if(are_friends_response[0]['are_friends'] is True):
try:
# Try to get Django account corresponding to friend
# Authenticate then login (or display disabled error message)
django_user = User.objects.get(username=request.COOKIES[API_KEY + '_user'])
user = authenticate(username=request.COOKIES[API_KEY + '_user'],
password=md5.new(request.COOKIES[API_KEY + '_user'] + settings.SECRET_KEY).hexdigest())
if user is not None:
if user.is_active:
login(request, user)
self.facebook_user_is_authenticated = True
else:
request.facebook_message = ACCOUNT_DISABLED_ERROR
self.delete_fb_cookies = True
else:
request.facebook_message = ACCOUNT_PROBLEM_ERROR
self.delete_fb_cookies = True
except User.DoesNotExist:
# There is no Django account for this Facebook user.
# Create one, then log the user in.
# Make request to FB API to get user's first and last name
user_info_params = {
'method': 'Users.getInfo',
'api_key': API_KEY,
'call_id': time.time(),
'v': '1.0',
'uids': request.COOKIES[API_KEY + '_user'],
'fields': 'first_name,last_name',
'format': 'json',
}
user_info_hash = self.get_facebook_signature(user_info_params)
user_info_params['sig'] = user_info_hash
user_info_params = urllib.urlencode(user_info_params)
user_info_response = simplejson.load(urllib.urlopen(REST_SERVER, user_info_params))
# Create user
user = User.objects.create_user(request.COOKIES[API_KEY + '_user'], '',
md5.new(request.COOKIES[API_KEY + '_user'] +
settings.SECRET_KEY).hexdigest())
user.first_name = user_info_response[0]['first_name']
user.last_name = user_info_response[0]['last_name']
user.save()
# Authenticate and log in (or display disabled error message)
user = authenticate(username=request.COOKIES[API_KEY + '_user'],
password=md5.new(request.COOKIES[API_KEY + '_user'] + settings.SECRET_KEY).hexdigest())
if user is not None:
if user.is_active:
login(request, user)
self.facebook_user_is_authenticated = True
else:
request.facebook_message = ACCOUNT_DISABLED_ERROR
self.delete_fb_cookies = True
else:
request.facebook_message = ACCOUNT_PROBLEM_ERROR
self.delete_fb_cookies = True
# Not my FB friend
else:
request.facebook_message = NOT_FRIEND_ERROR
self.delete_fb_cookies = True
# Cookie session expired
else:
logout(request)
self.delete_fb_cookies = True
# Cookie values don't match hash
else:
logout(request)
self.delete_fb_cookies = True
# Logged in
else:
# If FB Connect user
if API_KEY in request.COOKIES:
# IP hash cookie set
if 'fb_ip' in request.COOKIES:
try:
real_ip = request.META['HTTP_X_FORWARDED_FOR']
except KeyError:
real_ip = request.META['REMOTE_ADDR']
# If IP hash cookie is NOT correct
if request.COOKIES['fb_ip'] != md5.new(real_ip + API_SECRET + settings.SECRET_KEY).hexdigest():
logout(request)
self.delete_fb_cookies = True
# FB Connect user without hash cookie set
else:
logout(request)
self.delete_fb_cookies = True
# Something else happened. Make sure user doesn't have site access until problem is fixed.
except:
request.facebook_message = PROBLEM_ERROR
logout(request)
self.delete_fb_cookies = True
def process_response(self, request, response):
# Delete FB Connect cookies
# FB Connect JavaScript may add them back, but this will ensure they're deleted if they should be
if self.delete_fb_cookies is True:
response.delete_cookie(API_KEY + '_user')
response.delete_cookie(API_KEY + '_session_key')
response.delete_cookie(API_KEY + '_expires')
response.delete_cookie(API_KEY + '_ss')
response.delete_cookie(API_KEY)
response.delete_cookie('fbsetting_' + API_KEY)
self.delete_fb_cookies = False
if self.facebook_user_is_authenticated is True:
try:
real_ip = request.META['HTTP_X_FORWARDED_FOR']
except KeyError:
real_ip = request.META['REMOTE_ADDR']
response.set_cookie('fb_ip', md5.new(real_ip + API_SECRET + settings.SECRET_KEY).hexdigest())
# process_response() must always return a HttpResponse
return response
# Generates signatures for FB requests/cookies
def get_facebook_signature(self, values_dict, is_cookie_check=False):
signature_keys = []
for key in sorted(values_dict.keys()):
if (is_cookie_check and key.startswith(API_KEY + '_')):
signature_keys.append(key)
elif (is_cookie_check is False):
signature_keys.append(key)
if (is_cookie_check):
signature_string = ''.join(['%s=%s' % (x.replace(API_KEY + '_',''), values_dict[x]) for x in signature_keys])
else:
signature_string = ''.join(['%s=%s' % (x, values_dict[x]) for x in signature_keys])
signature_string = signature_string + API_SECRET
return md5.new(signature_string).hexdigest()
|
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Comments
To allow other ways of logging in (normal Django accounts, OpenID, etc), then I had to make a lot of changes to get this working. In the end I don't think a middleware is the right approach. I plan to try this next: django-facebookconnect
Here's what I had to change to get this snippet working:
Change 'simplejson' (external library) to 'json' (built-in for Python 2.6 and 3+)
Facebook wouldn't give me the user details (user.getInfo call) without a session key, so add this line to user_info_params around line 95:
'session_key': request.COOKIES[settings.FACEBOOK_API_KEY + '_session_key']
This Middleware must come before the auth middleware, because this logs people in
In process_response line 205 to be able to logout I changed it to:
if request.user.is_anonymous() and ..
At the top of process_request add:
if '/accounts/' in request.path: return
Oh, and in your template remember to add an onlogin to the fb:login-button to redirect you after login, otherwise nothing happens.
#
This code works perfectly well except when FB granted you infinite session key. In this case session expires field is set to 0.
I suggest updating the following line
if(datetime.fromtimestamp(float(request.COOKIES[API_KEY+'_expires'])) > datetime.now()):
with check for float(request.COOKIES[API_KEY+'_expires'])==0.
#