Django rest framework - Authentication error with PUT requests

Question

I have a very simple Resource like this for my model 'Presentacion'

class PresentacionResource(ModelResource):
    model = Presentacion
    fields = (some fields)
    ignore_fields = (few to ignore)

and I need to implement authentication for this, so as I read, I created two wrappers

class AuthListOrCreateModelView(ListOrCreateModelView):
    permissions = (IsAuthenticated, )
class AuthInstanceModelView(InstanceModelView):
    permissions = (IsAuthenticated, )

And then in my in my urls.py

url(r'^presentaciones/$', AuthListOrCreateModelView.as_view(resource=PresentacionResource), name='presentacion-root'),
url(r'^presentaciones/(?P<id>[0-9]+)$', AuthInstanceModelView.as_view(resource=PresentacionResource), name='presentacion'),

This is working fine for the GET 'presentaciones/' requests but when I try to make a PUT request, I'm getting a 403 FORBIDDEN

What's strange to me is that GET is working fine: as long as I'm logged, it's responding correctly but if I logout it responds with 403 FORBIDDEN.

Answer 1

If you are using Django's session based authentication, then you may be tripping over the CSRF protection built into Django (see UserLoggedInAuthentication class[1]).

If this is the case, you will need to ensure that a CSRF cookie gets sent to the client and then you can adapt the jQuery instructions[2] to send the X-CSRFToken header with requests that may change data.

[1] http://django-rest-framework.org/_modules/authentication.html

[2] https://docs.djangoproject.com/en/dev/ref/contrib/csrf/#ajax

Answer 2

If the issue is the X-CSRF token header you can modify the Backbone.sync like this to send a token with each POST, PUT, DELETE request.

        /* alias away the sync method */
        Backbone._sync = Backbone.sync;

        /* define a new sync method */
        Backbone.sync = function(method, model, options) {

            /* only need a token for non-get requests */
            if (method == 'create' || method == 'update' || method == 'delete') {
                // CSRF token value is in an embedded meta tag 
                var csrfToken = $("meta[name='csrf_token']").attr('content');

                options.beforeSend = function(xhr){
                    xhr.setRequestHeader('X-CSRFToken', csrfToken);
                };
            }

            /* proxy the call to the old sync method */
            return Backbone._sync(method, model, options);
        };

Answer 3

I realize this is an older post, but I was dealing with this problem recently. Expanding on @orangewarp's answer and using django documentation (https://docs.djangoproject.com/en/dev/ref/contrib/csrf/#ajax), here's a solution:

This solution uses the csrftoken cookie. Another solution would be to create a csrf token endpoint in your API and grab the csrf from there.

  Backbone._sync = Backbone.sync;

  Backbone.sync = function(method, model, options) {
      //from django docs
      function getCookie(name) {
          var cookieValue = null;
          if (document.cookie && document.cookie != '') {
              var cookies = document.cookie.split(';');
              for (var i = 0; i < cookies.length; i++) {
                  var cookie = jQuery.trim(cookies[i]);
                  // Does this cookie string begin with the name we want?
                  if (cookie.substring(0, name.length + 1) == (name + '=')) {
                      cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                      break;
                  }
              }
          }
          return cookieValue;
      }

      /* only need a token for non-get requests */
      if (method == 'create' || method == 'update' || method == 'delete') {
          var csrfToken = getCookie('csrftoken');

          options.beforeSend = function(xhr){
              xhr.setRequestHeader('X-CSRFToken', csrfToken);
          };
      }

      return Backbone._sync(method, model, options);
  };