AD FS 2.0 Authentication and AJAX

Question

I have a web site that is trying to call an MVC controller action on another web site. These sites are both setup as relying party trusts in AD FS 2.0. Everything authenticates and works fine when opening pages in the browser window between the two sites. However, when trying to call a controller action from JavaScript using the jQuery AJAX method it always fails. Here is a code snippet of what I'm trying to do...

$.ajax({
  url: "relyingPartySite/Controller/Action",
  data: { foobar },
  dataType: "json",
  type: "POST",
  async: false,
  cache: false,
  success: function (data) {
    // do something here
  },
  error: function (data, status) {
    alert(status);
  }
});

The issue is that AD FS uses JavaScript to post a hidden html form to the relying party. When tracing with Fiddler I can see it get to the AD FS site and return this html form which should post and redirect to the controller action authenticated. The problem is this form is coming back as the result of the ajax request and obviously going to fail with a parser error since the ajax request expects json from the controller action. It seems like this would be a common scenario, so what is the proper way to communicate with AD FS from AJAX and handle this redirection?

Answer 1

You have two options. More info here.

The first is to share a session cookie between an entry application (one that is HTML based) and your API solutions. You configure both applications to use the same WIF cookie. This only works if both applications are on the same root domain. See the above post or this stackoverflow question.

The other option is to disable the passiveRedirect for AJAX requests (as Gutek's answer). This will return a http status code of 401 which you can handle in Javascript. When you detect the 401, you load a dummy page (or a "Authenticating" dialog which could double as a login dialog if credentials need to be given again) in an iFrame. When the iFrame has completed you then attempt the call again. This time the session cookie will be present on the call and it should succeed.

//Requires Jquery 1.9+
var webAPIHtmlPage = "http://webapi.somedomain/preauth.html"

function authenticate() {
    return $.Deferred(function (d) {
        //Potentially could make this into a little popup layer 
        //that shows we are authenticating, and allows for re-authentication if needed
        var iFrame = $("<iframe></iframe>");
        iFrame.hide();
        iFrame.appendTo("body");
        iFrame.attr('src', webAPIHtmlPage);
        iFrame.load(function () {
            iFrame.remove();
            d.resolve();
        });
    });
};

function makeCall() {
    return $.getJSON(uri)
                .then(function(data) {
                        return $.Deferred(function(d) { d.resolve(data); });
                    },
                    function(error) {
                        if (error.status == 401) {
                            //Authenticating, 
                            //TODO:should add a check to prevnet infinite loop
                            return authenticate().then(function() {
                                //Making the call again
                                return makeCall();

                            });
                        } else {
                            return $.Deferred(function(d) {
                                d.reject(error);
                            });
                        }
                });
}

Answer 2

If you do not want to receive HTML with the link you can handle AuthorizationFailed on WSFederationAuthenticationModule and set RedirectToIdentityProvider to false on Ajax calls only.

for example:

FederatedAuthentication.WSFederationAuthenticationModule.AuthorizationFailed += (sender, e) =>
{
    if (Context.Request.RequestContext.HttpContext.Request.IsAjaxRequest())
    {
        e.RedirectToIdentityProvider = false;
    }
};

This with Authorize attribute will return you status code 401 and if you want to have something different, then you can implement own Authorize attribute and write special code on Ajax Request.

Answer 3

In the project which I currently work with, we had the same issue with SAML token expiration on the clientside and causing issues with ajax calls. In our particular case we needed all requests to be enqueud after the first 401 is encountered and after successful authentication all of them could be resent. The authentication uses the iframe solution suggested by Adam Mills, but also goes a little further in case user credentials need to be entered, which is done by displaying a dialog informing the user to login on an external view (since ADFS does not allow displaying login page in an iframe atleast not default configuration) during which waiting request are waiting to be finished but the user needs to login on from an external page. The waiting requests can also be rejected if user chooses to Cancel and in those cases jquery error will be called for each request.

Here's a link to a gist with the example code:

https://gist.github.com/kavhad/bb0d8e4a446496a6c05a

Note my code is based on usage of jquery for handling all ajax request. If your ajax request are being handled by vanilla javascript, other libraries or frameworks then you can perhaps find some inspiration in this example. The usage of jquery ui is only because of the dialog and stands for a small portion of the code which could easly be swapped out.

Update Sorry I changed my github account name and that's why link did not work. It should work now.

Answer 4

First of all you say you are trying to make an ajax call to another website, does your call conforms to same origin policy of web browsers? If it does then you are expecting html as a response from your server, changedatatype of the ajax call to dataType: "html", then insert the form into your DOM.

Answer 5

Perhaps the 2 first posts of this serie will help you. They consider ADFS and AJAX requests

What I think I would try to do is to see why the authentication cookies are not transmitted through ajax, and find a mean to send them with my request. Or wrap the ajax call in a function that pre authenticate by retrieving the html form, appending it hidden to the DOM, submitting it (it will hopefully set the good cookies) then send the appropriate request you wanted to send originally

Answer 6

You can do only this type of datatype

"xml": Treat the response as an XML document that can be processed via jQuery. 

"html": Treat the response as HTML (plain text); included script tags are evaluated. 

"script": Evaluates the response as JavaScript and evaluates it. 

"json": Evaluates the response as JSON and sends a JavaScript Object to the success callback. 

If you can see in your fiddler that is returning only html then change your data type to html or if that only a script code then you can use script.

Answer 7

You should create a file anyname like json.php and then put the connection to the relayparty website this should works $.ajax({ url: "json.php", data: { foobar }, dataType: "json", type: "POST", async: false, cache: false, success: function (data) { // do something here }, error: function (data, status) { alert(status); } });