POST method always return 403 Forbidden

Question

I have read Django - CSRF verification failed and several questions (and answers) related to django and POST method. One of the best-but-not-working-for-me answer is https://stackoverflow.com/a/4707639/755319

All of the approved answers suggest at least 3 things:

1. Use RequestContext as the third parameter of render_to_response_call
2. Add {% csrf_token %} in every form with POST method
3. Check the MIDDLEWARE_CLASSES in settings.py

I've done exactly as suggested, but the error still appeared. I use django 1.3.1 (from ubuntu 12.04 repository) and python 2.7 (default from ubuntu)

This is my View:

# Create your views here.
from django.template import RequestContext
from django.http import HttpResponse
from django.shortcuts import render_to_response
from models import BookModel

def index(request):
    return HttpResponse('Welcome to the library')

def search_form(request):
    return render_to_response('library/search_form.html')

def search(request):
    if request.method=='POST':
        if 'q' in request.POST:
            q=request.POST['q']
            bookModel = BookModel.objects.filter(title__icontains=q)
            result = {'books' : bookModel,}
            return render_to_response('library/search.html', result, context_instance=RequestContext(request))
        else:
            return search_form(request)
    else:
        return search_form(request)

and this is my template (search_form.html):

{% extends "base.html" %}
{% block content %}
<form action="/library/search/" method="post">
    {% csrf_token %} 
    <input type="text" name="q">
    <input type="submit" value="Search">
</form>
{% endblock %}

I've restarted the server, but the 403 forbidden error is still there, telling that CSRF verification failed.

I've 2 questions:

1. How to fix this error?
2. Why is it so hard to make a "POST" in django, I mean is there any specific reason to make it so verbose (I come from PHP, and never found such a problem before)?

Answer 1

I maybe wrong however I found the above solutions rather complex.

what worked for me was simply including my csrf token into my post request.

$.ajax({
    type: "POST",
    url: "/reports/",
    data: { csrfmiddlewaretoken: "{{ csrf_token }}",   // < here 
            state:"inactive" 
          },
    success: function() {
        alert("pocohuntus")
        console.log("prototype")
    }
})

Answer 2

This answer is for people that may encounter this same problem in the future.

The CSRF {{csrf_token}} template tag that is required for forms in Django prevent against Cross Site Request Forgeries. CSRF makes it possible for a malicious site that has been visited by a client's browser to make requests to your own server. Hence the csrf_token provided by django makes it simple for your django server and site to be protected against this type of malicious attack. If your form is not protected by csrf_token, django returns a 403 forbidden page. This is a form of protection for your website especially when the token wasn't left out intentionally.

But there are scenarios where a django site would not want to protect its forms using the csrf_token. For instance, I developed a USSD application and a view function is required to receive a POST request from the USSD API. We should note that the POST request was not from a form on the client hence the risk of CSRF impossible, since a malicious site cannot submit requests. The POST request is received when a user dials a USSD code and not when a form is submitted.

In other words, there are situations where a function will need to get a POST request and there would not be the need of {{csrf_token}}.

Django provides us with a decorator @csrf_exempt. This decorator marks a view as being exempt from the protection ensured by the middleware.

from django.views.decorators.csrf import csrf_exempt
from django.http import HttpResponse

@csrf_exempt
def my_view(request):
    return HttpResponse('Hello world')

Django also provides another decorator that performs the same function with {{csrf_token}}, but it doesn't reject incoming request. This decorator is @requires_csrf_token. For instance:

@requires_csrf_token
def my_view(request):
    c = {}
    # ...
    return render(request, "a_template.html", c)

The last decorator that will be mentioned in this post does exactly the same thing as {{csrf_token}} and it is called @csrf_protect. However, the use of this decorator by itself is not best practice because you might forget to add it to your views. For instance:

@csrf_protect
def my_view(request):
    c = {}
    # ...
    return render(request, "a_template.html", c)

Below are some links that will guide and explain better.

https://docs.djangoproject.com/en/1.7/ref/contrib/csrf/#module-django.views.decorators.csrf

https://docs.djangoproject.com/en/1.7/ref/contrib/csrf/

http://www.squarefree.com/securitytips/web-developers.html#CSRF