Using Django, I'm trying to login out a user but in server side as I'm using Django just for backend as our frontend is developed useing Reactjs + Node, and my problem is related when I try to login out the user. This is what I'm doing for this:
from django.contrib.sessions.models import Session
for s in Session.objects.all():
data = s.get_decoded()
if data.get('_auth_user_id', None) == str(user.id):
s.delete()
auth.logout(context)
the problem is that even when the logout code is executed, if I call the logout API again, user.is_authenticated is always True.
What do I have to do to receive False without checking the Session table manually to detect if the user is loged in ir not?
Regards
Related
I have been given a task to authenticate admin login programmatically and logout as well.
I am able to to do login but on logged out when I check which user I am logging out it says AnonymousUser. How can I make sure I log out current user which is logged it.
I am using Django REST framework and testing it on Postman.
#api_view(["POST"])
def adminLogin(request):
if(request.method=="POST"):
username = request.data["username"]
password = request.data["password"]
authenticated_user = authenticate(request,username=username, password=password)
if authenticated_user != None:
if(authenticated_user.is_authenticated and authenticated_user.is_superuser):
login(request,authenticated_user)
return JsonResponse({"Message":"User is Authenticated. "})
else:
return JsonResponse({"message":"User is not authenticated. "})
else:
return JsonResponse({"Message":"Either User is not registered or password does not match"})
#api_view(["POST"])
def adminLogout(request):
print(request.user)
logout(request)
return JsonResponse({"message":"LoggedOut"})
Logging in/logging out with a REST API makes not much sense. The idea of logging in/logging out, at least how Django implements it, is by means of the session, so with a cookie that has the session id.
API clients like Postman usually do not work with cookies: each request is made more or less independent of the previous one. If you thus make the next request without a reference to the session, then the view will not link a user to that request. Clients like AJAX that runs on the browser of course can work with cookies, since these are embedded in the browser that manages cookies. You can work with cookies in postman as specified in this tutorial [learning postman], but this is usually not how an API is supposed to work.
This is why APIs usually work with a token, for example a JWT token. When authenticating, these are given a token that might be valid for a short amount of time, and subsequently it uses that token to make any other request that should be authorized.
As the Django REST framework documentation on TokenAuthentication [drf-doc] says, you can define views that create, and revoke tokens. The page also discusses session authentication that thus can be used for AJAX requests.
But likely you are thus using the wrong means to do proper authentication for your REST API, and you thus might want to work with a token like a JWT token instead.
Using:
Django 1.11
Python 3.6
DRF with JWT in FE
I understand that the Django admin uses a session, and basic authentication.
What I did so far: Replaced the Django Admin authentication signin page with AWS-Cognito:
The user goes to domain/admin/*, redirected to signin in AWS
On successful signin the user is redirected to the redirect_uri, leads to a Django View
In the view I replace the code with tokens
I can't navigate to any Admin page - I am trying to redirect, but that doesn't work since I didn't login() the User
Stuck - I would like to associate the User with the fetched tokens and authenticate with every Admin page request, and when the user logs out delete the tokens
What to do next?
When I use JWT with the Front End application, every request.META has HTTP_AUTHORIZATION, and uses a suitable backend.
I know how to add backends, and potentially leverage the user.backend (I also use Cognito-JWT for other FE portions, so already wrote BE for that)
I need to find a way to replace the Django Admin sessions authentication with the fetched token
Thank you!
EDIT:
If I login() the user, and set it to a model backend that I have already I can navigate to any admin page - but using the session that I created when I logged the user in.
I would like to have the user be set to a new model backend, with authentication that uses a token (from Django backend docs):
class MyBackend:
def authenticate(self, request, token=None):
# Check the token and return a user.
...
How do I make the different Admin pages requests pass the token to the authentication?
Where do I store the token? (I could make a NewUserModel that is 1-1 with the Django User model, and place a token field there)
I am thinking of writing a middleware to capture all requests, and looking into the target URL - if Admin url, add the token to the HTTP_AUTHORIZATION once I fetch the user mentioned in #2 (the user is in every request due to DRF)
EDIT 2
My solution is getting more and more like this stack solution, I would have liked to know if there are any other options, but here is what I did so far:
I made a model that has a 1-1 user field, and a tokens field
As I am fetching/creating the user, I am also saving the tokens on the user's related model from #1 above
I created a middleware that is capturing any request in process_request, and has access to the user. I can see the tokens there as I access the user's related model from #1 above.
I am trying to set the HTTP_AUTHORIZATION header on the request, but cannot do that yet (currently stuck here)
In my backend, I am looking at the incoming request, and trying to fetch the HTTP_AUTHORIZATION - not there yet.
EDIT 3
I ended up just using the Django session as is - once the user authenticates with AWS-Cognito once, it is safe to assume that it is a legitimate User.
Then I just dump the Cognito-JWT, and login() the User.
Note: I am still interested in a solution that would drop the Django session for using the Cognito-JWT, and would love to hear suggestions.
I am using Flask-login with remember=False (the only cookie is the session cookie). When copy-pasting the session cookie after logging out, for some reason the session is still valid and the user is logged in. Even though the logged out session was deleted properly in the flask logout_user() function - meaning that the ["user_id"] was deleted from the session dictionary. It seems like the session is restored from the old cookie. can someone explain?
I do not really have a right answer for this yet, as I am investigating it myself, but there are a couple of points I would like to make here:
the logout_user() from Flask-login does not really seem to be invalidating the session. It just changes the 'session' cookie's value in the client (the browser). While in the backend this session is still alive.
An experiment to prove this would be: (a simple browser plugin like CookieManager can be used to perform this exercise)
login to the app
take a note of the 'session' cookie's value post successful login
now logout
now observer the 'session' cookie's value again. And you would
notice that it has now changed.
Replace this value with the 'session'cookie's value previously noted
in step 1 above.
Try visiting an internal authenticated page again.
Result : You would successfully be able to view an internal page without re-logging in, proving that the logout_user() never really invalidated the session but just changed the 'session' cookie in the client.
Howeverm, I am myself still taking a look into flask-login logout_user() definition and trying to make sense of it.
I had This issue too. After diagnosing what i found is the decorator #login_required *does not invalidate the User in server side after logout*, which is a security threat. This will be a cake walk for a Hacker to hack your application since they can easily extract all the request and header data from developer tool of your browser and can again send request to you server from outside of the application.For ex: If you have used any API in your application the it will be very easy for Hacker to get all the request data and resend a request using POSTMAN.
I solved this issue by creating a separate decorator "#authentication_required" and used in place of "#login_required". then it worked for me,though #login_required is supposed to do the same.
So basically while logging in i generated a random string(token) and sent to database and same string(token) is added to session of flask i.e session["token"]="akhfkjdbfnd334fndf" use any random string generator function.(session object is globally available if u r using flask . u can very well add any field to session). and while logout i again generate a string(token) and update the old token with newly generated token in database. So what #authentication_required will do is it will get the token from session object and the token which is present in database and try to compare the value. if both are same then only #authentication_required will let the client access api.and dont forget to do session.clear() after logout_user().
#---------------------------------------------------------------#
##authentication_required definition
def authentication_required(f):
#wraps(f)
def wrap(*args, **kwargs):
try:
user_id=session['user_id'] #assigning "user_id" from flask session object to a variable "user_id"
user=User_table.find_first(_id=user_id)#couhdb query syntax
#comparing api_token sent to session object at the login time with api_token in sent to database at login time. If both doesn't matches then user is redirected to login page.
if not session["token"]==user.token:
return redirect(url_for('login'))
else:
return f(*args, **kwargs)
except:
app.logger.info(Response('Request Did not came through header !', 401, {'WWW-Authenticate': 'Login failed'}))
return redirect(url_for('login_to system'))
return wrap
#---------------------------------------------------------------#
-------------------------------------------------------
login api code
#app.route('/login_to_system', methods=['GET', 'POST'])
def login_to_system():
form = LoginForm()
user = User_table.find_first(username=form.username.data)
login_user(user, remember=False)
try:
#Generating an random api_token at login time and will send to db
token_string=''.join(random.choices(string.ascii_uppercase + string.digits, k=14))
user.token=token_string #assigning token_string value to field api_token in database.
user.save() #saving the value in user table(using couch Db You can follow syntax as per you DB)
except Exception as error:
app.logger.error(str(error))
app.logger.info("before setting api_token in session")
session["token"]= token_string #adding a "token" to session object
#app.logger.info("Rendering login form")
return render_template('login.html', title='Sign In', form=form)
#-------------------------------------------------------#
#-----------------------------------#
#logout api code
#app.route('/logout')
def logout():
try:
user=User_table.find_first(_id=user_id)
#Generating a random token while logging out and will overwrite eariler token sent at login time send to database.
user.token=token_string=''.join(random.choices(string.ascii_uppercase + string.digits, k=17))
user.save()
except Exception as error:
app.logger.error(str(error))
logout_user()
session.clear()#clearing session
return redirect(url_for('Home page'))
#-----------------------------------#
Note: Seems like login_required is not working fine for me thats why i had to create another decorator but login_required also does the same thing but its strange that it not working for me.
I followed this method to have an API to login a user using Tastypie and Django Auth: Login with Tastypie
Once I log a user in through Tastypie, I received a session id I store in my app.
Now I want to logout the suer when he use the logout button -> how can I logout a user based on it's session id ? I wanted to use logout() function but it uses a request containing a user object as parameter and I don't have it with my javascript app.
I tried to find in the code how was made the logout function but it flush the sessionbase and I don't have such an object.
My idea: getting session based on session id and delete the row:
from django.contrib.sessions.models import Session
s = Session.objects.get(pk='2b1189a188b44ad18c35e113ac6ceead')
s.delete()
Is it a good idea ?
i've recently implemented a simple change password view in my django project. The thing is that the old session should be destroyed for security reasons. What's the best way of doing this without asking the user to log in again.
I think i could just logout/login him/her, something like this:
from django.contrib.auth import login as auth_login
from django.contrib.auth import logout as auth_logout
#login_required
def change_password(request):
# My stuff
request.user.set_password(new_password)
request.user.save()
# I need this:
logout(request)
login(request,request.user)
But i think this is not the best idea. What do you think?
Is there another way to do this?
Am I missing something? (I mean, is this secure)
Take a look at this app https://github.com/atugushev/django-password-session.
This package makes invalidated all sessions (except a current session) after change a password.
Also this feature finally was implemented in Django 1.7. See: https://docs.djangoproject.com/en/dev/topics/auth/default/#session-invalidation-on-password-change
I just found out that this is now a built-in feature of Django, and has been since 1.7:
https://docs.djangoproject.com/en/1.7/topics/auth/default/#session-invalidation-on-password-change
Essentially, all sessions now include a hash of the users' password, so if the user ever changes their password, all their existing sessions are automatically invalidated.
So, the short answer to your question is: upgrade django.
One possibly undesirable side effect of this change is that, by default, a user ends up having to log in again as soon as they change their password. So you probably actually want the current user session to stay logged in. See the docs already linked, Django's built-in views for password change do that for you default, or you can manually call a function called update_session_auth_hash
django clears the session on logout so you will be fine:
https://docs.djangoproject.com/en/dev/topics/auth/#django.contrib.auth.logout
When you call logout(), the session data for the current request is completely cleaned out. All existing data is removed. This is to prevent another person from using the same Web browser to log in and have access to the previous user's session data.
I don't understand whats are these security reasons that forces to reset session. But, the way is:
#login_required
def change_password(request):
request.user.set_password(new_password)
request.user.save()
username = request.user.username
logout(request)
user = authenticate(username=username, password=new_password) #<-- here!!
if user is not None:
login(request,user)
else:
#raise your exception
you should authenticate before login. Quoting doc:
Calling authenticate() first When you're manually logging a user in,
you must call authenticate() before you call login(). authenticate()
sets an attribute on the User noting which authentication backend
successfully authenticated that user (see the backends documentation
for details), and this information is needed later during the login
process.