I am trying to pass my session object from one class to another. But I am not sure whats happening.
class CreateSession:
def __init__(self, user, pwd, url="http://url_to_hit"):
self.url = url
self.user = user
self.pwd = pwd
def get_session(self):
sess = requests.Session()
r = sess.get(self.url + "/", auth=(self.user, self.pwd))
print(r.content)
return sess
class TestGet(CreateSession):
def get_response(self):
s = self.get_session()
print(s)
data = s.get(self.url + '/some-get')
print(data.status_code)
print(data)
if __name__ == "__main__":
TestGet(user='user', pwd='pwd').get_response()
I am getting 401 for get_response(). Not able to understand this.
What's a 401?
The response you're getting means that you're unauthorised to access the resource.
A session is used in order to persist headers and other prerequisites throughout requests, why are you creating the session every time rather than storing it in a variable?
As is, the session should work the only issue is that you're trying to call a resource that you don't have access to. - You're not passing the url parameter either in the initialisation.
Example of how you can effectively use Session:
from requests import Session
from requests.exceptions import HTTPError
class TestGet:
__session = None
__username = None
__password = None
def __init__(self, username, password):
self.__username = username
self.__password = password
#property
def session(self):
if self.__session is None:
self.__session = Session()
self.__session.auth = (self.__user, self.__pwd)
return self.__session
#session.setter
def session(self, value):
raise AttributeError('Setting \'session\' attribute is prohibited.')
def get_response(self, url):
try:
response = self.session.get(url)
# raises if the status code is an error - 4xx, 5xx
response.raise_for_status()
return response
except HTTPError as e:
# you received an http error .. handle it here (e contains the request and response)
pass
test_get = TestGet('my_user', 'my_pass')
first_response = test_get.get_response('http://your-website-with-basic-auth.com')
second_response = test_get.get_response('http://another-url.com')
my_session = test_get.session
my_session.get('http://url.com')
I have a little problem with web.py. Exacly I have problem with sessions.
Link to my app:
http://len.iem.pw.edu.pl/~witkowr1/apps/demo/
Login/password: wtq/wtq
Code:
# -*- coding: utf-8 -*-
import web
import json
from web.contrib.template import render_jinja
import datetime
prefix = '/~witkowr1/apps/demo'
urls = (
prefix + '/login','Login',
prefix + '/logout','Logout',
prefix + '/', 'Index',
)
app = web.application(urls, globals())
wsgi = app.wsgifunc()
session = web.session.Session(app, web.session.DiskStore('sessions'),initializer={'time':datetime.datetime.now()})
render = render_jinja('static', encoding = 'utf-8')
render._lookup.globals.update(assets=prefix+'/static')
class Login:
def GET(self):
web.seeother(prefix+'/')
def POST(self):
login = web.input().login
password = web.input().passwd
if login == 'wtq' and password == 'wtq':
session.logged_in = True
session.time = datetime.datetime.now()
last_login = web.cookies().get('time')
if last_login == None:
last_login_data = u'Zalogowałeś się pierwszy raz.'
else:
last_login_data = last_login
return render.logged(name=login, date_last_login=last_login_data)
else:
session.logged_in = False
error=u'Niepoprawne dane. SprĂłbuj jeszcze raz.'
return render.login(error_msg=error)
class Logout:
def GET(self):
web.seeother(prefix+'/')
def POST(self):
session.logged_in = False
web.setcookie('time',session.time)
message = u'Zostałeś poprawnie wylogowany.'
session.kill()
return render.login(error_msg=message)
class Index:
def GET(self):
return render.login()
if __name__ == "__main__":
app.run()
I would like to verify session and if I login early, I see site with latest login date.
Now, when I refresh the site, I must login again.
I think, that I check session, when I rendering HTML site, but I don't know, what I do it.
Please help!
The problem here is that you are not checking whether they are logged in if they access the page with GET method.
You would need to make a change like:
def GET(self):
if session.logged_in:
last_login = web.cookies().get('time')
if last_login == None:
last_login_data = u'Zalogowałeś się pierwszy raz.'
else:
last_login_data = last_login
return render.logged(name=login, date_last_login=last_login_data)
else:
web.seeother(prefix+'/')
But you should rewrite this, a lot, so that you are taken to another page once you are logged in, and that page is responsible for rendering this information. There is a lot of room for improvement in the structure of your application.
That said, the simple answer is - even though you store the session, the "GET" method of login is entirely unaware of sessions, and will always return the login prompt.
Not sure if you solved your problem already but since it looks like there are often some problems with sessions in web.py I pushed a small and crude demo of it to bitbucket. Works fine for me so hope this works for you.
You can get it via:
git clone https://victorkohler#bitbucket.org/victorkohler/webpy-login.git
I solved my problem.
Very stupid mistakes :)
Code:
# -*- coding: utf-8 -*-
import web
from web.contrib.template import render_jinja
import datetime
prefix = ''
urls = (
prefix + '/', 'Index',
prefix + '/login','Login',
prefix + '/logout','Logout',
)
app = web.application(urls, globals())
wsgi = app.wsgifunc()
web.config.debug = False
session = web.session.Session(app, web.session.DiskStore('sessions'),initializer={'time':datetime.datetime.now()})
render = render_jinja('static', encoding = 'utf-8')
render._lookup.globals.update(assets=prefix+'/static')
allowed = (
('user','user'),
)
class Login:
def GET(self):
web.seeother(prefix+'/')
def POST(self):
login = web.input().login
passwd = web.input().passwd
if(login,passwd) in allowed:
session.logged_in = True
session.login = login
session.time = datetime.datetime.now()
last_login = web.cookies().get('time')
if last_login == None:
last_login_data = u'Zalogowałeś się pierwszy raz.'
else:
last_login_data = last_login
return render.logged(name=login, date_last_login = last_login_data)
else:
session.logged_in = False
error=u'Niepoprawne dane. Spróbuj jeszcze raz.'
return render.login(error_msg=error)
class Logout:
def GET(self):
web.seeother(prefix+'/')
def POST(self):
session.logged_in = False
web.setcookie('time',session.time)
message = u'Zostałeś poprawnie wylogowany.'
session.kill()
return render.login(error_msg=message)
class Index:
def GET(self):
if session.get ('logged_in') == True:
last_login = web.cookies().get('time')
if last_login == None:
last_login_data = u'Zalogowałeś się pierwszy raz.'
else:
last_login_data = last_login
return render.logged(name=session.get ('login'), date_last_login = last_login_data)
else:
return render.login()
if __name__ == "__main__":
app.run()
This is not an answer to your question but an extension of the question. I have a similar solution to the login from the webpy cookbook (http://webpy.org/cookbook/userauthbasic) but would like to load the variable allowed from a database.
allowed = (
('user','user'),
)
When I tried a read to assign the value to the variable it comes out as "None" when executed in the login class.
def readUsersDb():
def POST(self):
# load user data into allowed variable
usersDbFilePath = 'userdata/irf/default/'
usersDbFile = 'usersDb.db'
usersDbFilePath = usersDbFilePath + usersDbFile
conn = sqlite3.connect(usersDbFilePath)
c = conn.cursor()
c.execute('SELECT * FROM users')
output = c.fetchall()
conn.close()
global allowed
allowed = output
readUsersDb()
The login functions when the variable allowed is hard coded. I used the format from the database read and it still functions as expected so it is not a format issue.
#response: [(u'user1', 'user1'), (u'user2', 'user2'), (u'user3', 'user3')]
Hopefully someone has tried to do this previously. If it is a faux pas to add a question as an answer I apologize ahead of time.
I could reproduce my bug using servside OAuth2.0 only so it's not javascript and the issue is that I must reload to make login / logout take effect and I want it to work without javascript. I have an idea that making logout twice makes logout effective so I could use a custom request handler for /login and/or /logour or just /sessionchange that will do a self.redirect but it's not the clean solution. Maybe you can take a look at the code and see why I must logout twice ie I must reload and can I workaround this using a self.redirect ? Am I using cookies the right way, the new cookie, or do I get it mixed up? I'm doing this both for the website and for the FB app. I'll be glad if you can come with any suggestion. There's a background of 2 related questions from before I removed the Javascript. And BTW should I use class Facebook or facebook.py? I think I commented out where the old cookie is set and that this will be correct once OAuth 2.0 handles my authentication serverside. Can you comment or answer? Thank you in advance if you can review and comment.
How to make my welcome text appear?
How to make this page reload on login / logout?
Why my strange results rendering the user object?
login.html
{% load i18n %}
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head> <title>{% trans "Log in" %}</title>
<script type="text/javascript">
var _gaq = _gaq || [];
_gaq.push(['_setAccount', '{{analytics}}']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
</script>
</head>
<body>
<div id="fb-root"></div>
<script>
window.fbAsyncInit = function() {
FB.init({
appId : '164355773607006', // App ID
channelURL : '//WWW.KOOLBUSINESS.COM/static/channel.html', // Channel File
status : true, // check login status
cookie : true, // enable cookies to allow the server to access the session
oauth : true, // enable OAuth 2.0
xfbml : true // parse XFBML
});
// Additional initialization code here
};
// Load the SDK Asynchronously
(function(d){
var js, id = 'facebook-jssdk'; if (d.getElementById(id)) {return;}
js = d.createElement('script'); js.id = id; js.async = true;
js.src = "//connect.facebook.net/en_US/all.js";
d.getElementsByTagName('head')[0].appendChild(js);
}(document));
</script>
<img src="/_/img/loginwithfacebook.png">
<img src="/_/img/loginwithgoogle.png"><br>{% if user %}Logout Google{% endif %}
{% if current_user %}Logout Facebook {% endif %}
{% if current_user %}Logout Facebook JS {% endif %}
</body>
</html>
class BaseHandler(webapp.RequestHandler):
facebook = None
user = None
csrf_protect = True
#property
def current_user(self):
if not hasattr(self, "_current_user"):
self._current_user = None
cookie = facebook.get_user_from_cookie(
self.request.cookies, facebookconf.FACEBOOK_APP_ID, facebookconf.FACEBOOK_APP_SECRET)
logging.debug("logging cookie"+str(cookie))
if cookie:
# Store a local instance of the user data so we don't need
# a round-trip to Facebook on every request
user = FBUser.get_by_key_name(cookie["uid"])
logging.debug("user "+str(user))
logging.debug("username "+str(user.name))
if not user:
graph = facebook.GraphAPI(cookie["access_token"])
profile = graph.get_object("me")
user = FBUser(key_name=str(profile["id"]),
id=str(profile["id"]),
name=profile["name"],
profile_url=profile["link"],
access_token=cookie["access_token"])
user.put()
elif user.access_token != cookie["access_token"]:
user.access_token = cookie["access_token"]
user.put()
self._current_user = user
return self._current_user
def initialize(self, request, response):
"""General initialization for every request"""
super(BaseHandler, self).initialize(request, response)
try:
self.init_facebook()
self.init_csrf()
self.response.headers[u'P3P'] = u'CP=HONK' # iframe cookies in IE
except Exception, ex:
self.log_exception(ex)
raise
def handle_exception(self, ex, debug_mode):
"""Invoked for unhandled exceptions by webapp"""
self.log_exception(ex)
self.render(u'error',
trace=traceback.format_exc(), debug_mode=debug_mode)
def log_exception(self, ex):
"""Internal logging handler to reduce some App Engine noise in errors"""
msg = ((str(ex) or ex.__class__.__name__) +
u': \n' + traceback.format_exc())
if isinstance(ex, urlfetch.DownloadError) or \
isinstance(ex, DeadlineExceededError) or \
isinstance(ex, CsrfException) or \
isinstance(ex, taskqueue.TransientError):
logging.warn(msg)
else:
logging.error(msg)
def set_cookie(self, name, value, expires=None):
if value is None:
value = 'deleted'
expires = datetime.timedelta(minutes=-50000)
jar = Cookie.SimpleCookie()
jar[name] = value
jar[name]['path'] = u'/'
if expires:
if isinstance(expires, datetime.timedelta):
expires = datetime.datetime.now() + expires
if isinstance(expires, datetime.datetime):
expires = expires.strftime('%a, %d %b %Y %H:%M:%S')
jar[name]['expires'] = expires
self.response.headers.add_header(*jar.output().split(u': ', 1))
def render(self, name, **data):
"""Render a template"""
if not data:
data = {}
data[u'js_conf'] = json.dumps({
u'appId': facebookconf.FACEBOOK_APP_ID,
u'canvasName': facebookconf.FACEBOOK_CANVAS_NAME,
u'userIdOnServer': self.user.id if self.user else None,
})
data[u'logged_in_user'] = self.user
data[u'message'] = self.get_message()
data[u'csrf_token'] = self.csrf_token
data[u'canvas_name'] = facebookconf.FACEBOOK_CANVAS_NAME
data[u'current_user']=self.current_user
data[u'user']=users.get_current_user()
data[u'facebook_app_id']=facebookconf.FACEBOOK_APP_ID
user = users.get_current_user()
data[u'logout_url']=users.create_logout_url(self.request.uri) if users.get_current_user() else 'https://www.facebook.com/dialog/oauth?client_id=164355773607006&redirect_uri='+self.request.uri
host=os.environ.get('HTTP_HOST', os.environ['SERVER_NAME'])
data[u'host']=host
if host.find('.br') > 0:
logo = 'Montao.com.br'
logo_url = '/_/img/montao_small.gif'
analytics = 'UA-637933-12'
domain = None
else:
logo = 'Koolbusiness.com'
logo_url = '/_/img/kool_business.png'
analytics = 'UA-3492973-18'
domain = 'koolbusiness'
data[u'domain']=domain
data[u'analytics']=analytics
data[u'logo']=logo
data[u'logo_url']=logo_url
data[u'admin']=users.is_current_user_admin()
if user:
data[u'greeting'] = ("Welcome, %s! (sign out)" %
(user.nickname(), users.create_logout_url("/")))
self.response.out.write(template.render(
os.path.join(
os.path.dirname(__file__), 'templates', name + '.html'),
data))
def init_facebook(self):
facebook = Facebook()
user = None
# initial facebook request comes in as a POST with a signed_request
if u'signed_request' in self.request.POST:
facebook.load_signed_request(self.request.get('signed_request'))
# we reset the method to GET because a request from facebook with a
# signed_request uses POST for security reasons, despite it
# actually being a GET. in webapp causes loss of request.POST data.
self.request.method = u'GET'
#self.set_cookie(
#'u', facebook.user_cookie, datetime.timedelta(minutes=1440))
elif 'u' in self.request.cookies:
facebook.load_signed_request(self.request.cookies.get('u'))
# try to load or create a user object
if facebook.user_id:
user = FBUser.get_by_key_name(facebook.user_id)
if user:
# update stored access_token
if facebook.access_token and \
facebook.access_token != user.access_token:
user.access_token = facebook.access_token
user.put()
# refresh data if we failed in doing so after a realtime ping
if user.dirty:
user.refresh_data()
# restore stored access_token if necessary
if not facebook.access_token:
facebook.access_token = user.access_token
if not user and facebook.access_token:
me = facebook.api(u'/me', {u'fields': _USER_FIELDS})
try:
friends = [user[u'id'] for user in me[u'friends'][u'data']]
user = FBUser(key_name=facebook.user_id,
id=facebook.user_id, friends=friends,
access_token=facebook.access_token, name=me[u'name'],
email=me.get(u'email'), picture=me[u'picture'])
user.put()
except KeyError, ex:
pass # ignore if can't get the minimum fields
self.facebook = facebook
self.user = user
def init_csrf(self):
"""Issue and handle CSRF token as necessary"""
self.csrf_token = self.request.cookies.get(u'c')
if not self.csrf_token:
self.csrf_token = str(uuid4())[:8]
self.set_cookie('c', self.csrf_token)
if self.request.method == u'POST' and self.csrf_protect and \
self.csrf_token != self.request.POST.get(u'_csrf_token'):
raise CsrfException(u'Missing or invalid CSRF token.')
def set_message(self, **obj):
"""Simple message support"""
self.set_cookie('m', base64.b64encode(json.dumps(obj)) if obj else None)
def get_message(self):
"""Get and clear the current message"""
message = self.request.cookies.get(u'm')
if message:
self.set_message() # clear the current cookie
return json.loads(base64.b64decode(message))
class Facebook(object):
"""Wraps the Facebook specific logic"""
def __init__(self, app_id=facebookconf.FACEBOOK_APP_ID,
app_secret=facebookconf.FACEBOOK_APP_SECRET):
self.app_id = app_id
self.app_secret = app_secret
self.user_id = None
self.access_token = None
self.signed_request = {}
def api(self, path, params=None, method=u'GET', domain=u'graph'):
"""Make API calls"""
if not params:
params = {}
params[u'method'] = method
if u'access_token' not in params and self.access_token:
params[u'access_token'] = self.access_token
result = json.loads(urlfetch.fetch(
url=u'https://' + domain + u'.facebook.com' + path,
payload=urllib.urlencode(params),
method=urlfetch.POST,
headers={
u'Content-Type': u'application/x-www-form-urlencoded'})
.content)
if isinstance(result, dict) and u'error' in result:
raise FacebookApiError(result)
return result
def load_signed_request(self, signed_request):
"""Load the user state from a signed_request value"""
try:
sig, payload = signed_request.split(u'.', 1)
sig = self.base64_url_decode(sig)
data = json.loads(self.base64_url_decode(payload))
expected_sig = hmac.new(
self.app_secret, msg=payload, digestmod=hashlib.sha256).digest()
# allow the signed_request to function for upto 1 day
if sig == expected_sig and \
data[u'issued_at'] > (time.time() - 86400):
self.signed_request = data
self.user_id = data.get(u'user_id')
self.access_token = data.get(u'oauth_token')
except ValueError, ex:
pass # ignore if can't split on dot
#property
def user_cookie(self):
"""Generate a signed_request value based on current state"""
if not self.user_id:
return
payload = self.base64_url_encode(json.dumps({
u'user_id': self.user_id,
u'issued_at': str(int(time.time())),
}))
sig = self.base64_url_encode(hmac.new(
self.app_secret, msg=payload, digestmod=hashlib.sha256).digest())
return sig + '.' + payload
#staticmethod
def base64_url_decode(data):
data = data.encode(u'ascii')
data += '=' * (4 - (len(data) % 4))
return base64.urlsafe_b64decode(data)
#staticmethod
def base64_url_encode(data):
return base64.urlsafe_b64encode(data).rstrip('=')
facebook.py
#!/usr/bin/env python
#
# Copyright 2010 Facebook
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Python client library for the Facebook Platform.
This client library is designed to support the Graph API and the official
Facebook JavaScript SDK, which is the canonical way to implement
Facebook authentication. Read more about the Graph API at
http://developers.facebook.com/docs/api. You can download the Facebook
JavaScript SDK at http://github.com/facebook/connect-js/.
If your application is using Google AppEngine's webapp framework, your
usage of this module might look like this:
user = facebook.get_user_from_cookie(self.request.cookies, key, secret)
if user:
graph = facebook.GraphAPI(user["access_token"])
profile = graph.get_object("me")
friends = graph.get_connections("me", "friends")
"""
from google.appengine.dist import use_library
use_library('django', '1.2')
import cgi
import hashlib
import time
import urllib
#from django.utils import translation, simplejson as json
# Find a JSON parser
try:
# For Google AppEngine
from django.utils import simplejson
_parse_json = lambda s: simplejson.loads(s)
except ImportError:
try:
import simplejson
_parse_json = lambda s: simplejson.loads(s)
except ImportError:
import json
_parse_json = lambda s: json.loads(s)
class GraphAPI(object):
"""A client for the Facebook Graph API.
See http://developers.facebook.com/docs/api for complete documentation
for the API.
The Graph API is made up of the objects in Facebook (e.g., people, pages,
events, photos) and the connections between them (e.g., friends,
photo tags, and event RSVPs). This client provides access to those
primitive types in a generic way. For example, given an OAuth access
token, this will fetch the profile of the active user and the list
of the user's friends:
graph = facebook.GraphAPI(access_token)
user = graph.get_object("me")
friends = graph.get_connections(user["id"], "friends")
You can see a list of all of the objects and connections supported
by the API at http://developers.facebook.com/docs/reference/api/.
You can obtain an access token via OAuth or by using the Facebook
JavaScript SDK. See http://developers.facebook.com/docs/authentication/
for details.
If you are using the JavaScript SDK, you can use the
get_user_from_cookie() method below to get the OAuth access token
for the active user from the cookie saved by the SDK.
"""
def __init__(self, access_token=None):
self.access_token = access_token
def get_object(self, id, **args):
"""Fetchs the given object from the graph."""
return self.request(id, args)
def get_objects(self, ids, **args):
"""Fetchs all of the given object from the graph.
We return a map from ID to object. If any of the IDs are invalid,
we raise an exception.
"""
args["ids"] = ",".join(ids)
return self.request("", args)
def get_connections(self, id, connection_name, **args):
"""Fetchs the connections for given object."""
return self.request(id + "/" + connection_name, args)
def put_object(self, parent_object, connection_name, **data):
"""Writes the given object to the graph, connected to the given parent.
For example,
graph.put_object("me", "feed", message="Hello, world")
writes "Hello, world" to the active user's wall. Likewise, this
will comment on a the first post of the active user's feed:
feed = graph.get_connections("me", "feed")
post = feed["data"][0]
graph.put_object(post["id"], "comments", message="First!")
See http://developers.facebook.com/docs/api#publishing for all of
the supported writeable objects.
Most write operations require extended permissions. For example,
publishing wall posts requires the "publish_stream" permission. See
http://developers.facebook.com/docs/authentication/ for details about
extended permissions.
"""
assert self.access_token, "Write operations require an access token"
return self.request(parent_object + "/" + connection_name, post_args=data)
def put_wall_post(self, message, attachment={}, profile_id="me"):
"""Writes a wall post to the given profile's wall.
We default to writing to the authenticated user's wall if no
profile_id is specified.
attachment adds a structured attachment to the status message being
posted to the Wall. It should be a dictionary of the form:
{"name": "Link name"
"link": "http://www.example.com/",
"caption": "{*actor*} posted a new review",
"description": "This is a longer description of the attachment",
"picture": "http://www.example.com/thumbnail.jpg"}
"""
return self.put_object(profile_id, "feed", message=message, **attachment)
def put_comment(self, object_id, message):
"""Writes the given comment on the given post."""
return self.put_object(object_id, "comments", message=message)
def put_like(self, object_id):
"""Likes the given post."""
return self.put_object(object_id, "likes")
def delete_object(self, id):
"""Deletes the object with the given ID from the graph."""
self.request(id, post_args={"method": "delete"})
def request(self, path, args=None, post_args=None):
"""Fetches the given path in the Graph API.
We translate args to a valid query string. If post_args is given,
we send a POST request to the given path with the given arguments.
"""
if not args: args = {}
if self.access_token:
if post_args is not None:
post_args["access_token"] = self.access_token
else:
args["access_token"] = self.access_token
post_data = None if post_args is None else urllib.urlencode(post_args)
file = urllib.urlopen("https://graph.facebook.com/" + path + "?" +
urllib.urlencode(args), post_data)
try:
response = _parse_json(file.read())
finally:
file.close()
if response.get("error"):
raise GraphAPIError(response["error"]["type"],
response["error"]["message"])
return response
class GraphAPIError(Exception):
def __init__(self, type, message):
Exception.__init__(self, message)
self.type = type
##### NEXT TWO FUNCTIONS PULLED FROM https://github.com/jgorset/facepy/blob/master/facepy/signed_request.py
import base64
import hmac
def urlsafe_b64decode(str):
"""Perform Base 64 decoding for strings with missing padding."""
l = len(str)
pl = l % 4
return base64.urlsafe_b64decode(str.ljust(l+pl, "="))
def parse_signed_request(signed_request, secret):
"""
Parse signed_request given by Facebook (usually via POST),
decrypt with app secret.
Arguments:
signed_request -- Facebook's signed request given through POST
secret -- Application's app_secret required to decrpyt signed_request
"""
if "." in signed_request:
esig, payload = signed_request.split(".")
else:
return {}
sig = urlsafe_b64decode(str(esig))
data = _parse_json(urlsafe_b64decode(str(payload)))
if not isinstance(data, dict):
raise SignedRequestError("Pyload is not a json string!")
return {}
if data["algorithm"].upper() == "HMAC-SHA256":
if hmac.new(secret, payload, hashlib.sha256).digest() == sig:
return data
else:
raise SignedRequestError("Not HMAC-SHA256 encrypted!")
return {}
def get_user_from_cookie(cookies, app_id, app_secret):
"""Parses the cookie set by the official Facebook JavaScript SDK.
cookies should be a dictionary-like object mapping cookie names to
cookie values.
If the user is logged in via Facebook, we return a dictionary with the
keys "uid" and "access_token". The former is the user's Facebook ID,
and the latter can be used to make authenticated requests to the Graph API.
If the user is not logged in, we return None.
Download the official Facebook JavaScript SDK at
http://github.com/facebook/connect-js/. Read more about Facebook
authentication at http://developers.facebook.com/docs/authentication/.
"""
cookie = cookies.get("fbsr_" + app_id, "")
if not cookie:
return None
response = parse_signed_request(cookie, app_secret)
if not response:
return None
args = dict(
code = response['code'],
client_id = app_id,
client_secret = app_secret,
redirect_uri = '',
)
file = urllib.urlopen("https://graph.facebook.com/oauth/access_token?" + urllib.urlencode(args))
try:
token_response = file.read()
finally:
file.close()
access_token = cgi.parse_qs(token_response)["access_token"][-1]
return dict(
uid = response["user_id"],
access_token = access_token,
)
Some log traces are
2011-10-18 18:25:07.912
logging cookie{'access_token': 'AAACVewZBArF4BACUDwnDap5OrQQ5dx0sHEKuPJkIJJ8GdXlYdni5K50xKw6s8BSIDZCpKBtVWF9maHMoJeF9ZCRRYM1zgZD', 'uid': u'32740016'}
D 2011-10-18 18:25:07.925
user <__main__.FBUser object at 0x39d606ae980b528>
D 2011-10-18 18:25:07.925
username Niklas R
Now looking at the code that does this it seems to me that I'm confusing the module facebook with the variable facebook where one is the class facebook from the example project and one is the new recommended module facebook.py:
class BaseHandler(webapp.RequestHandler):
facebook = None
user = None
csrf_protect = True
#property
def current_user(self):
if not hasattr(self, "_current_user"):
self._current_user = None
cookie = facebook.get_user_from_cookie(
self.request.cookies, facebookconf.FACEBOOK_APP_ID, facebookconf.FACEBOOK_APP_SECRET)
logging.debug("logging cookie"+str(cookie))
if cookie:
# Store a local instance of the user data so we don't need
# a round-trip to Facebook on every request
user = FBUser.get_by_key_name(cookie["uid"])
logging.debug("user "+str(user))
logging.debug("username "+str(user.name))
if not user:
graph = facebook.GraphAPI(cookie["access_token"])
profile = graph.get_object("me")
user = FBUser(key_name=str(profile["id"]),
id=str(profile["id"]),
name=profile["name"],
profile_url=profile["link"],
access_token=cookie["access_token"])
user.put()
elif user.access_token != cookie["access_token"]:
user.access_token = cookie["access_token"]
user.put()
self._current_user = user
return self._current_user
How to add Facebook as OAuth 2.0 provider: Here's how I make "Login with facebook" for my website with OAuth instead of javascript / cookie this is python only for OAuth 2.0 with Facebook and as far as I can tell it's working:
class FBUser(db.Model):
id = db.StringProperty(required=True)
created = db.DateTimeProperty(auto_now_add=True)
updated = db.DateTimeProperty(auto_now=True)
name = db.StringProperty(required=True)
profile_url = db.StringProperty()
access_token = db.StringProperty(required=True)
name = db.StringProperty(required=True)
picture = db.StringProperty()
email = db.StringProperty()
friends = db.StringListProperty()
class I18NPage(I18NHandler):
def get(self):
if self.request.get('code'):
args = dict(
code = self.request.get('code'),
client_id = facebookconf.FACEBOOK_APP_ID,
client_secret = facebookconf.FACEBOOK_APP_SECRET,
redirect_uri = 'http://www.koolbusiness.com/',
)
logging.debug("client_id"+str(args))
file = urllib.urlopen("https://graph.facebook.com/oauth/access_token?" + urllib.urlencode(args))
try:
logging.debug("reading file")
token_response = file.read()
logging.debug("read file"+str(token_response))
finally:
file.close()
access_token = cgi.parse_qs(token_response)["access_token"][-1]
graph = main.GraphAPI(access_token)
user = graph.get_object("me") #write the access_token to the datastore
fbuser = main.FBUser.get_by_key_name(user["id"])
logging.debug("fbuser "+str(fbuser))
if not fbuser:
fbuser = main.FBUser(key_name=str(user["id"]),
id=str(user["id"]),
name=user["name"],
profile_url=user["link"],
access_token=access_token)
fbuser.put()
elif fbuser.access_token != access_token:
fbuser.access_token = access_token
fbuser.put()
The login link is
<img src="/_/img/loginwithfacebook.png"> that redirects and allows me to pick up the access_token in the method above and logout is straightforward:
{% trans "Log out" %}
Here is a very basic class for handling sessions on App Engine:
"""Lightweight implementation of cookie-based sessions for Google App Engine.
Classes:
Session
"""
import os
import random
import Cookie
from google.appengine.api import memcache
_COOKIE_NAME = 'app-sid'
_COOKIE_PATH = '/'
_SESSION_EXPIRE_TIME = 180 * 60
class Session(object):
"""Cookie-based session implementation using Memcached."""
def __init__(self):
self.sid = None
self.key = None
self.session = None
cookie_str = os.environ.get('HTTP_COOKIE', '')
self.cookie = Cookie.SimpleCookie()
self.cookie.load(cookie_str)
if self.cookie.get(_COOKIE_NAME):
self.sid = self.cookie[_COOKIE_NAME].value
self.key = 'session-' + self.sid
self.session = memcache.get(self.key)
if self.session:
self._update_memcache()
else:
self.sid = str(random.random())[5:] + str(random.random())[5:]
self.key = 'session-' + self.sid
self.session = dict()
memcache.add(self.key, self.session, _SESSION_EXPIRE_TIME)
self.cookie[_COOKIE_NAME] = self.sid
self.cookie[_COOKIE_NAME]['path'] = _COOKIE_PATH
print self.cookie
def __len__(self):
return len(self.session)
def __getitem__(self, key):
if key in self.session:
return self.session[key]
raise KeyError(str(key))
def __setitem__(self, key, value):
self.session[key] = value
self._update_memcache()
def __delitem__(self, key):
if key in self.session:
del self.session[key]
self._update_memcache()
return None
raise KeyError(str(key))
def __contains__(self, item):
try:
i = self.__getitem__(item)
except KeyError:
return False
return True
def _update_memcache(self):
memcache.replace(self.key, self.session, _SESSION_EXPIRE_TIME)
I would like some advices on how to improve the code for better security.
Note: In the production version it will also save a copy of the session in the datastore.
Note': I know there are much more complete implementations available online though I would like to learn more about this subject so please don't answer the question with "use that" or "use the other" library.
Here is a suggestion for simplifying your implementation.
You are creating a randomized temporary key that you use as the session's key in the memcache. You note that you will be storing the session in the datastore as well (where it will have another key).
Why not randomize the session's datastore key, and then use that as the one and only key, for both the database and the memcache (if necessary)? Does this simplification introduce any new security issues?
Here's some code for creating a randomized datastore key for the Session model:
# Get a random integer to use as the session's datastore ID.
# (So it can be stored in a cookie without being 'guessable'.)
random.seed();
id = None;
while None==id or Session.get_by_id( id ):
id = random.randrange( sys.maxint );
seshKey = db.Key.from_path( 'Session', id );
session = Session( key = seshKey );
To get the ID from the session (i.e. to store in the cookie) use:
sid = session.key().id();
To retrieve the session instance after the 'sid' has been read from the cookie:
session = Session.get_by_id( sid );
Here are a couple of additional security measures you could add.
First, I think it is pretty common to use information stored in the session instance to validate each new request. For example, you could verify that the IP address and user-agent don't change during a session:
newip = str( request.remote_addr );
if sesh.ip_addr != newip:
logging.warn( "Session IP has changed to %s." % newip);
newua = rh.request.headers.get( 'User-Agent', None );
if sesh.agent != newua:
logging.warn( "Session UA has changed to %s." % newua );
Also, perhaps it would be better to prevent the session from being renewed indefinitely? I think that sites such as Google will eventually ask you to sign-in again if you try to keep a session going for a long time.
I guess it would be easy to slowly decrease the _SESSION_EXPIRE_TIME each time the session gets renewed, but that isn't really a very good solution. Ideally the choice of when to force the user to sign-in again would take into account the flow and security requirements of your site.