Csrf token verification fails between two Django web applications - django

I am trying to pass csrf token between two web application to make one POST data to the other.
"client" application (C) asks csrf token to "server" application (S) via a GET operation.
S responds to C with a form:
<form id='csrfRequestForm' name='csrfForm' action='http://{{ context_path }}/ajax/getcsrf' method='post'>
<!-- csrf token -->
{% csrf_token %}
<!-- datas to POST follow -->
...
</form>
C has to submit this form to action (mapped on a url used by S) in order to POST datas to S.
When C tries to do it, csrf verification fails. I've checked GET's result and csrf token is received with the form. I have django.middleware.csrf.CsrfViewMiddleware keyword listed under MIDDLEWARE CLASSES in settings.py and RequestContext is passed when rendering form's view with render_to_response(... RequestContext(request))
What am I doing wrong?
Thanks

Try defining your context and returning it like this...
context = RequestContext(request, {
'request': request
})
return render_to_response(..., context_instance=context)

This is by design, and disallows for cross site POST execution. One option you have is to mark the methods you would like to be able to execute as safe, as per the django docs:
https://docs.djangoproject.com/en/dev/ref/contrib/csrf/

I wasn't able to resolve it in your way, but I managed out how to do it:
C go directly to S via javascript opening a popup with:
window.open("http://<S_address>/<path_to_request_form>");
In this way, user using C that is logged via a third party authentication server (I forgot to mention it earlier, sorry), is still logged in the popup window in S and receives the form in it with a correct csrf token. I don't know if it's correct but it works.
Thanks for your time

Related

Prevent form resubmission with user refresh and need to submit data to webpage using Django

I've seen this question a few times and can't find an option that works in my situation.
I have a webpage that you can get to via a POST. It requires an 'example_id' be sent to the server.
The webpage has a form for the user to fill out. When they submit the form, I need the user to return to same page.
I need to prevent user 'refresh' from resubmitting the form. Most common solution I have found is:
return HttpResponseRedirect('/<web_page/')
I have tried this and adding kargs to the function parameters, but it doesn't seem to work.
Update:
I got my scenario to work by using the csrf token ({% csrf_token %}) . If the user refreshes the page, then the csrf token will be the same. So I check for this in my view and handle this scenario differently.
The solution I found.
I got my scenario to work by using the csrf token: {% csrf_token %}
If the user refreshes the page, then the csrf token will be the same. So I check for this in my view and handle this scenario differently than I would normally.

django CSRF token cookie not set for some users

I have been getting sporadic CSRF errors in an app that is mostly working ok. I do everything as I'm supposed to do: I use {% csrf_token %} in my template for normal forms and in my ajax POSTs I set the X-CSRFToken header:
$.ajaxSetup({
beforeSend: function(xhr, settings) {
xhr.setRequestHeader("X-CSRFToken", $.cookie('csrftoken'));
},
});
I'm even forcing the cookie to be set in all views by writing a custom Middleware that calls get_token
def CSRFForceCookieMiddleware(get_response):
def middleware(request):
response = get_response(request)
get_token(request) # Force to set cookie in all responses
return response
return middleware
Everything works OK in my localhost and in production for most users. But for some users I get 403 CSRF validation error.
I added a lot of debug info. Turns out that even if CsrfViewMiddleware is setting the csrftoken is setting the cookie in the response, in the actual browser the cookie is not set ($.cookie('csrftoken') is null). So when the ajax call is made, there is no cookie present in the request.
So, I guess this pretty much means that some users' browsers are blocking this cookie? Anyone else had this experience?
Most browsers have an option to "block all cookies". You may want to detect that in javascript and give your users a warning that some functional cookies are required for the site to work correctly. There's another SO question that shows how to do that.
Alternatively, grab the token from a hidden input field ({% csrf_token %} will add that field in your template). That should always work.

CRSF cookie not set in iframed Django View within another site

I have a Django app with about a dozen views that I am currently hosting on Heroku. I can do POST requests just fine to the app when directly going to the app url, and I have the 'django.middleware.csrf.CsrfViewMiddleware' enabled. I am running Django 2.1
I am currently having an issue where I am trying to embed this Django app within an iframe, on another site that I host on Weebly. I always get a 403 error when trying to do a post on any of the Django forms. The reason is "CSRF cookie not set."
I am doing this through Chrome on Ubuntu. I checked the Applications tab in the Developer console, and do see the csrftoken key-value pair set in the cookie for the Heroku domain. The Weebly domain does not contain the csrftoken key-value pair. I figured it would just use the cookie from the Heroku app domain and use the csrftoken, but that doesn't appear to be the case.
In Django, here are my settings regarding CSRF:
CSRF_COOKIE_SECURE = False
CSRF_TRUSTED_ORIGINS = ['example123.herokuapp.com',
'app123.weebly.com']
I REALLY don't want to disable security or use the csrf_exempt decorator, as that feels like a hack. I am pulling my hair out on this one!
EDIT:
{% csrf_token %} is in the form, and I can see the hidden field "csrfmiddlewaretoken":
<input type="hidden" name="csrfmiddlewaretoken" value="XXXXXXXXXXXXXXXXXXXXXXywkFTfTC9ttYiOTD0O8uF49SvRjaUWgWeLU0h2PjP2">
There are two different things with csrf in django
1. Csrfmiddlewaretoken : {% csrf_token %}
example of set-token header
2. CSRFcookie : I don't think that you did this one.
example of same request giving different csrf-token
here the images shown are both the examples of one of my app for a specific request
We do often confuse second with the first one. In the second case, the server sets a cookie in the first get request with a csrf token (this is a cookie and not the csrfmiddlewaretoken ), it needs to be sent every-time for csrf cookie verification. This is done by the browser itself and we mostly don't notice it. However the problem arises with using CORS (different origins of request like android/angular app etc).

Form action and its usage in Django

First Quesiton:
This form submits to demo_form?name=ABC
<form action="demo_form" method="get">
name: <input type="text" name="name"><br>
<input type="submit" value="Submit">
</form>
Is there a way to make it submit to demo_form/ABC/?
Second Question:
Even if users don't use my form, if they use a web crawler to simply visit demo_form?name=ABC or demo_form/ABC/, it would yield the same result. I want to prevent that. What's the best way of making those two URLs only valid if the user submit the name via my form? I am learning django so hopefully the solution would work with django framework.
Thanks in advance!
Is there a way to make it submit to demo_form/ABC/?
You could intercept the submission in JavaScript, construct the URL manually, then set location. That would break if JS wasn't available.
More sanely, you could send an HTTP 301 redirect response when you get the request for demo_form?name=ABC
What's the best way of making those two URLs only valid if the user submit the name via my form?
Generally speaking, visiting a form should not be a pre-requisite for anything involving a GET request. A large portion of the point of GET is that the results are bookmarkable, linkable, etc.
It would be more understandable if it was a POST request, as those are intended to change data on the server and you will want to protect against CSFR. The standard protection against CSRF is a token stored in the form and in a cookie

Django and JEditable: CSRF error

I started using the Jeditable plugin with Django and quickly ran into a CSRF error: "CSRF verification failed. Request aborted.", "CSRF token missing or incorrect"
As of this writing the Jeditable plugin seems have been last updated in 2008--sometime after this Django began requiring CSRF tokens for POST requests.
How do you add Django CSRF data to Jeditable?
The answer to this question came from a similar jeditable post on CSRF. The CSRF token may be added in the "submitdata" variable.
Expanding the 1st jeditable example for a Django post look something like this:
$(document).ready(function() {
$('.edit').editable('http://www.example.com/save.php', {
submitdata : { csrfmiddlewaretoken : "{{ csrf_token }}"}
});
});
Note, in order to show the "csrf_token" value instead of an entire form field, the "csrf_token" is wrapped in {{..}} instead of {% .. %}.
The preferred method for providing the CSRF token through AJAX requests is by setting the X-CSRFToken header to the value of the CSRF token. You'll need to modify the constructed request object to set the header value.
There's also a helper function provided to get the CSRF token from the cookie, rather than relying on providing it in the template, which considerably simpifies things, i.e. you don't have to ship the JS code inline or set the token as a variable in JS in the template itself.