#JWT_Required decorator Exception Handling - flask

I am using an auth API using JWT and it works great.
This API is being used to authorize users for my web app. For this to work, I store JWT access_tokens as cookie manually with Flask.
I secure my resource with #JWT_required decorator and if I try to access a secure resource with a valid token everything works fine.
However, if the access token is missing or invalid/expired I get a JSON saying:
{
"message": "Missing cookie \"access_token_cookie\""
}
This is obvious the right message but rather then showing a JSON I want to redirect to the appropriate statuscode error page that is provided by Flask - in this case 401.
I have tried adding error handling for Flask and JWT Manager
Custom decorator, although I have played only poorly with this as I believe there has to be solution within FLASK-JWT-extended
#app.route('/dashbord')
#jwt_required
def dashbord():
return render_template('dashbord.html', title='Home')
My goal is to redirect to appropriate error page 404, 403, 401 if anything is wrong with the access token.
THE SOLUTION:
#jwt.unauthorized_loader
def my_invalid_token_callback(expired_token):
return render_template('401.html', title='Home')

Here's the solution Benjo posted at the bottom of his question:
#jwt.unauthorized_loader
def my_invalid_token_callback(expired_token):
return render_template('401.html', title='Home')

Here is the documentation for changing the results for invalid tokens: https://flask-jwt-extended.readthedocs.io/en/stable/changing_default_behavior.html#changing-callback-functions

Related

Django REST social login with dj_rest_auth does not authenticate the user

I am building an application. The client is built with Next.js and the backend with Django and Django REST framework.
In this application, I would like to have social login.
So far, my situation is this.
I have set up the OAuth on the Google dashboard
On the client, I am using next-auth - The client is successfully calling Google and getting an access token from there.
On the client, the callback that runs after getting the access token from Google makes a call my Django API.
I have set up the backend with dj_rest_auth - My settings are almost identical to the ones described here.
Once the client callback runs and calls my Django API with the access token from Google, I successfully get on the client an access token and a refresh token.
If it is a new user loggin in the first time, a new user is created in Djangos DB
const response = await fetch(`${djangoAPIurl}/api/social/login/google/`, {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({
access_token: accessToken,
id_token: idToken
})
});
const data = await response.json();
const { access_token, refresh_token } = data;
Both access_token and refresh_token are defined and appear to be valid tokens.
So far, everything happens as expected. My issue appears after this point.
In my api, I have another view defined.
#api_view(['GET'])
#authentication_classes([SessionAuthentication, BasicAuthentication, TokenAuthentication])
#permission_classes([IsAuthenticated])
def test_view(request):
current_user = request.user
print('current_user.auth: ', current_user.is_authenticated)
response = JsonResponse({"received": True})
return response
From my client, I am attempting to call this view in the following way.
const response = await fetch(`${djangoAPIurl}/api/test/test_view/`, {
headers: new Headers({
Authorization: `Bearer ${session.accessToken}`
})
});
The header is constructed correctly, with session.accessToken being the value I got from the api/social/login/google/ call and the request is routed correctly, however, it fails with Forbidden 403 because the user is not authenticated. I have removed the authentication and permission decrators and the request ends up being processed by the view, and there, upon inspection of the user, it is an Anonymous user. I have also tried changing Bearer to Token, to no avail.
Do you have any advice what I might be doing wrong or missing? Have I completely missunderstood how to use the token I get back from api/social/login/google/? All advice is much appreicated!
I think this is because your secret for hashing JWTS on the client side and server side is not same. Next-Auth automatically creates a secret key for hashing jwt's and dj_rest_auth does the same, unless you explicitly tell them both to use the same secret for hashing jwts. I'm a bit late to answer this, but Hope this will help future people😁😁.

Django CSRF Token present but still getting 403 Forbidden Error

I am trying to set up a Django API that receives POST requests with some JSON data and basically sends emails to a list of recipients. The logic is rather simple:
First I have the view for when I create a blog post. In the template, I include the csrf_token as specified on the Django Documentation. When I hit the submit button, behind the scene the create-post view, in addition to creating the post, makes a request (I am using the requests module) to the API which is charged with sending the emails. This is the piece of logic the sends the request to the API:
data = {
"title": new_post.title,
"summary": new_post.summary,
"link": var["BASE_URL"] + f"blog/post/{new_post.slug}"
}
csrf_token = get_token(request)
# print(csrf_token)
headers = {"X-CSRFToken": csrf_token}
requests.post(var["BASE_URL"] + "_api/send-notification/", json=data, headers=headers)
As you can see I am adding the X-CSRFToken to the headers which I generate through the get_token() method, as per the Django docs. However, the response in the API is a 403 Forbidden status CSRF Token not set.
I have checked the headers in the request and the token is indeed present. In addition, I have been providing other routes to the API and I have been using it for AJAX calls which again is very simple just follow the Django docs and they work perfectly well.
The problem seems to arise when I make the call from within the view, AJAX calls are handle by Javascript static files, and as I said they work fine.
I have thought that Django didn't allow the use of 2 CSRF tokens on the same page (one for the submit form and the other in the view by get_token()), but that's not the problem.
This is typically the error I get:
>>> Forbidden (CSRF cookie not set.): /_api/send-notification/
>>> "POST /_api/send-notification/ HTTP/1.1" 403 2864
I have read several similar questions on SO but they mostly involved using the csrf_exempt decorator, which in my opinion is not really a solution. It just gets rid of the CRSF token usefulness altogether.
Does anyone have any idea what might be causing this problem?
Thanks
Error tries to tell you that you need to add token into cookie storage like that:
cookies = {'csrftoken': csrf_token}
requests.post(var["BASE_URL"] + "_api/send-notification/", json=data, headers=headers, cookies=cookies)

Manually validate flask-extended-jwt's access token

I have a SPA app that contains an form with an upload file field. I have a rest API whose endpoints are protected via flask-extended-jwt JWT. To authenticate the REST endpoints I use #jwt_required. I want to authenticate the upload request as well.
Because of the client side I can't add an Authorization Bearer header so I thought to add the access token as a hidden field when submitting the form.
What is the best way to manually validate the JWT access token after I read it from the form?
class Upload(Resource):
def post(self):
#TODO: check for access token
access_token = None
if 'access_token' in request.form and request.form['access_token']:
access_token = request.form['access_token']
else:
message = json.dumps({'message': 'Invalid or missing token', 'success': False})
return Response(response=message, status=401, mimetype='text/plain')
if access_token:
#TODO: validate_token(access_token)
Thank you
Author of flask-jwt-extended here. That's a great question. There is currently no supported way to do that in the extension, the grabbing the token from the request and decoding it are tightly coupled together. This would be hard to de-couple because there is a lot of conditional things that are going on when the full decode chain runs. For example, checking the CSRF value only if the request is sent in via a cookie, or differentiating between an access and refresh token for the sake of the blacklisting feature.
A generalized function could be created, it's signature would look something like decode_and_verify_jwt(encoded_token, is_access_token=True, check_csrf=False). However, this would complicate the rest of the code in flask_jwt_extended and be a rather confusing function to use for the general case.
I think in this case it would be easier just to add a fourth lookup in the extension, so you could use something like:
app.config['JWT_TOKEN_LOCATION'] = ['headers', 'forms']
app.config['JWT_FORM_KEY'] = 'access_token'
# Use the rest of the application normally
If you want to make a ticket on the github page so I can track this, I would be happy to work on it.

How to make a POST simple JSON using Django REST Framework? CSRF token missing or incorrect

Would appreciate someone showing me how to make a simple POST request using JSON with Django REST framework. I do not see any examples of this in the tutorial anywhere?
Here is my Role model object that I'd like to POST. This will be a brand new Role that I'd like to add to the database but I'm getting a 500 error.
{
"name": "Manager",
"description": "someone who manages"
}
Here is my curl request at a bash terminal prompt:
curl -X POST -H "Content-Type: application/json" -d '[
{
"name": "Manager",
"description": "someone who manages"
}]'
http://localhost:8000/lakesShoreProperties/role
The URL
http://localhost:8000/lakesShoreProperties/roles
DOES work with a GET request, and I can pull down all the roles in the database, but I can not seem to create any new Roles. I have no permissions set. I'm using a standard view in views.py
class RoleDetail(generics.RetrieveUpdateDestroyAPIView):
queryset = Role.objects.all()
serializer_class = RoleSerializer
format = None
class RoleList(generics.ListCreateAPIView):
queryset = Role.objects.all()
serializer_class = RoleSerializer
format = None
And in my urls.py for this app, the relevant url - view mappings are correct:
url(r'^roles/$', views.RoleList.as_view()),
url(r'^role/(?P<pk>[0-9]+)/$', views.RoleDetail.as_view()),
Error message is:
{
"detail": "CSRF Failed: CSRF token missing or incorrect."
}
What is going on here and what is the fix for this? Is localhost a cross site request? I have added #csrf_exempt to RoleDetail and RoleList but it doesn't seem to change anything. Can this decorator even be added to a class, or does it have to be added to a method?
Adding the #csrf_exempt decorate, my error becomes:
Request Method: POST
Request URL: http://127.0.0.1:8000/lakeshoreProperties/roles/
Django Version: 1.5.1
Exception Type: AttributeError
Exception Value:
'function' object has no attribute 'as_view'
Then I disabled CSRF throughtout the entire app, and I now get this message:
{"non_field_errors": ["Invalid data"]} when my JSON object I know is valid json. It's a non-field error, but I'm stuck right here.
Well, it turns out that my json was not valid?
{
"name": "admin",
"description": "someone who administrates"
}
vs
[
{
"name": "admin",
"description": "someone who administrates"
}
]
Having the enclosing brackets [], causes the POST request to fail. But using the jsonlint.com validator, both of my json objects validate.
Update: The issue was with sending the POST with PostMan, not in the backend. See https://stackoverflow.com/a/17508420/203312
CSRF is exempted by default in Django REST Framework. Therefore, curl POST request works fine. POSTMAN request call returned CSRF incorrect because POSTMAN included csrf token if it is found in Cookies. You can solve this by cleaning up Cookies.
It's from your REST Framework settings. in your settings.py file, your REST_FRAMEWORK should have the following.
REST_FRAMEWORK = {
'DEFAULT_AUTHENTICATION_CLASSES': (
'rest_framework.authentication.TokenAuthentication',
),
'DEFAULT_PERMISSION_CLASSES': (
'rest_framework.permissions.AllowAny',
),
}
This will set your REST Framework to use token authentication instead of csrf authentication. And by setting the permission to AllowAny, you can authenticate only where you want to.
You probably need to send along the CSRF token with your request. Check out https://docs.djangoproject.com/en/1.7/ref/contrib/csrf/#csrf-ajax
Update: Because you've already tried exempting CSRF, maybe this could help (depending on which version of Django you're using): https://stackoverflow.com/a/14379073/977931
OK, well now of course I take back what I said. CSRF does work as intended.
I was making a POST request using a chrome plugin called POSTMAN.
My POST request fails with CSRF enabled.
But a curl POST request using
curl -X POST -H "Content-Type: application/json" -d '
{
"name": "Manager",
"description": "someone who manages"
}' http://127.0.0.1:8000/lakeshoreProperties/roles/
works fine...
I had to take off the braces, i.e., [], and make sure there is a slash after the 's' in roles, i.e., roles/, and csrf enabled did not throw any errors.
I'm not sure what the difference between calling using POSTMAN is vs using curl, but POSTMAN is run in the web browser which is the biggest difference. That said, I disabled csrf for the entire class RoleList but one identical request works with Curl, but fails with POSTMAN.
To give an update on current status, and sum up a few answers:
AJAX requests that are made within the same context as the API they are interacting with will typically use SessionAuthentication. This ensures that once a user has logged in, any AJAX requests made can be authenticated using the same session-based authentication that is used for the rest of the website.
AJAX requests that are made on a different site from the API they are communicating with will typically need to use a non-session-based authentication scheme, such as TokenAuthentication.
Therefore, answers recommending to replace SessionAuthentication with TokenAuthentication may solve the issue, but are not necessarily totally correct.
To guard against these type of attacks, you need to do two things:
Ensure that the 'safe' HTTP operations, such as GET, HEAD and OPTIONS cannot be used to alter any server-side state.
Ensure that any 'unsafe' HTTP operations, such as POST, PUT, PATCH and DELETE, always require a valid CSRF token.
If you're using SessionAuthentication you'll need to include valid CSRF tokens for any POST, PUT, PATCH or DELETE operations.
In order to make AJAX requests, you need to include CSRF token in the HTTP header, as described in the Django documentation.
Therefore, it is important that csrf is included in header, as for instance this answer suggests.
Reference: Working with AJAX, CSRF & CORS, Django REST framework documentation.
As you said your URL was
http://localhost:8000/lakesShoreProperties/roles
Postman has some issues with localhost.
Sending the POST to 127.0.0.1:8000/your-api/endpoint instead did the trick for me.
the old Postman is having a problem with csrf tokens because it does not working with cookies.
I suggest for you to switch to the new version of postman, it works with cookies and you will not face this problem again.
if you have set AllowAny permission and you facing with csrf issue
REST_FRAMEWORK = {
'DEFAULT_PERMISSION_CLASSES': [
'rest_framework.permissions.AllowAny'
]
}
then placing following in the settings.py will resolve the issue
REST_SESSION_LOGIN = False

Django-social-auth google oauth token usage

I'm using Django-socila-auth plugin. It uses google API for Oauth 1.0 Authentication. Question is have anybody used it with google python API (gdata). I mean how to apply auth session_token, stored in django-social-auth model to my api call.
Can you help me with code to get this token from model and apply to gdata.PhotoService() instance. For now it is like this:
#getting model instance from django-social-auth model
association = Association.objects.get(user=request.user)
google_session_token=association.handle
google_secret=association.secret
#token string from django-social-auth
#model Association field "handle" looks like:
#google_session_token = '.......XG84PjwytqJkvr8WQhDxm1w-JplWK5zPndSHB13f.........'
gd_client = gdata.photos.service.PhotosService()
gd_client.debug = 'true'
gd_client.auth_token = google_session_token
#image.image is a file field, but problem not in this.
#it tries to send file in debug text.
#It just recieves 403 unauthorised callback.
photo = gd_client.InsertPhotoSimple(
'/data/feed/api/user/default/albumid/default', 'New Photo',
'Uploaded using the API', image.image, content_type='image/jpeg')
I'm recieving error
403 Invalid token string.
I understand that it needs secret too but how to apply it to API for auth?(To receive authorization to post photos.). BTW I added Picassa feed URL, as an option string for social-auth to ask permissions, so token I have asks for Picassa feed permissions when authorizing with google.
BTW. Google tutorial I've used is: here
I understand it's Oauth 1.0 rather than AusSub, but question is:
how to authenticate with token and secret I have and post a photo with this permission?
Just to answer my own problem. I used wrong way to do it, because problem in 'gd_client' and AuthSub.
It must check token on server. And it can not do it on localhost. You need to look ahead to Oauth/Oauth2 for better debugging and so on... No matter that it is much complex than AuthSub