Do not receive a response from FBAS.init - facebook

It was working till Thursday of last week, but I'm wondering if something changed cause the code has been the same since then.
I pass the following JSON information to the FBAS.init call from my app in facebook
{"oauth":true,"appId":"MYAPPID"}
Here's the relevant code:
//We call Facebook API init call like so:
trace("init");
Facebook.init(_appKey, _fbInitResponse);
//Here's our callback
protected function _fbInitResponse(success:Object, fail:Object):void
{
trace("fbInitResponse: success = " + success);
// User logged in successfully
if (success)
{
trace("\t session recieved!");
_session = success;
dispatchEvent(new Event(FacebookEvent.INIT));
}
else
{
trace("ERROR: " + fail);
}
}

Actually: It looks like a bug with Facebook not redirecting to the Secure Canvas URL properly. The hack below is a short-term work-around, but this looks like a bug on Facebooks end.
Ran into the same problem as you. Was a mismatch when a user was using https to access the Facebook app, but the app page was being served in http.
A Facebook auth change has been propagating to users since March.
I assume this was the change to cause the bustage:
https://developers.facebook.com/roadmap/#enhanced-auth-dialog
The tip found in this answer helped me:
Facebook JavaScript SDK over HTTPS loading non-secure items
I put the: FB._https = (window.location.protocol == "https:");
I put it right after the fb-root div in a script element. Very hacky.

Related

Parse Unity Facebook 400 Bad Request

I am using the Facebook SDK and Parse plugin. I can sucessfully login with Parse and Facebook independently. When I try to 'sign up' for parse using my Facebook access token I get a 400 bad request.
I believe my parse.com account is setup correctly (I have augmented the authentication section with my application ID(s) and secret(s) (for main app and test app).
Here is my code.
// FB Init and Login here. It works.
var logInTask = ParseFacebookUtils.LogInAsync(FB.UserId, FB.AccessToken, DateTime.UtcNow.AddDays(1));
while (!logInTask.IsCompleted)
{
yield return 1;
}
if (logInTask.IsCanceled || logInTask.IsFaulted)
{
var error = logInTask.Exception as AggregateException;
foreach (var e in error.InnerExceptions)
{
// Bad Request Here
Debug.LogError(e);
}
}
What am I doing wrong, how can I resolve this ?
I suspect the issue here is that you're passing in a DateTime object for token expiration, when you should be passing in the expires_at value that came back with your Facebook login. I believe this is an integer.

Facebook PHP SDK usage stand alone - how do the Facebook sessions/cookies work?

I'm utilizing the Facebook PHP SDK on its own. I do not want to use the JS SDK at all.
Because getUser(); from the SDK can return a user id even if the user is not logged in, I have opted for using a try/catch statement to check if the user is logged in.
try
{
$me = $CI->facebook->api('/me');
$CI->our_fb['is_fb']='YES';
echo "hello";
}
catch(FacebookApiException $e)
{
echo "catch";
}
This statement is included in the global include file of all of my files (for simplicity).
So, depending on the situation, I generate a Facebook login URL. The expected functionality is that the user logins to Facebook, authorises the app, is returned to the redirect URI set in the login URL at which point the try statement will execute, and $CI->our_fb['is_fb'] will be set.
This is however not happening.
If the user is already logged into Facebook and the app is authorised, it works perfectly. SUCCESS
If the user is not logged into Facebook, once redirected the variable is not set. FAILURE
If the user is logged in but the app is NOT authorised after redirect the variable is not set. FAILURE.
In the latter two cases if you simply refresh the page, the variable is set - SUCCESS. Refreshing the page is however unnecessary/pointless extra effort.
My problem is that if you need to login to FB/or authorise the app e.g the first time you login with FB, you have an additional unneeded refresh, and I don't know why.
I suspect it is something to do with the cookie/session? Which saves the access token that I assume is returned/passed to the SDK automatically not being set at the same time?
Anyone got any ideas?
If you're having an app on facebook (tab or canvas). PHP SDK only get the User ID on initial loading of a page because a signed_request is sent with the request to your app.
But, when the app refreshes, the signed_request is lost (as it's facebook who send it).
So, in this case, you can append the signed_request to every URLs your use in your app - but that's really not optimal as the signed_request won't be regenarated - neither refreshed.
Your only real option is to rely on the JS SDK to set cookie correctly and allow getUser to work as expected. This is required because you're considered as a third-party app in Facebook (being in an iframe) and most browser will block you from setting cookies - so you need a work around handled by the JS SDK for you. You can search for cross-domain cookies or third-party cookie for explanation about the workarounds, but these workaround only work via JS scripting and iframe management.
Also, be sure to setup the JS SDK correctly: channel file, cookie allowed, and send P3P headers (for IE).
You can also check this related question: A proper approach to FB auth
About website, the same mostly stays (but you have no signed_request). At this point, seriously consider using the JS SDK as it's way easier. Or else, you can make sure your app flow follow these guidelines: https://developers.facebook.com/docs/concepts/login/login-architecture/
The way I am seeing this is, you are trying to avoid that refresh if the user is not logged in and precedes to log in after the page has initially loaded.
So what you can do is make an ajax request to another page on your site, say for example id.php, which just loads the php sdk and echo $userid; and then you can grab the user id after login without the refresh.
Basically the cookie is used to save the signed request and session is used to save 'state', 'code', 'access_token', 'user_id'. If the above are present PHP SDK uses them, no matter if they are valid or not.
I think your problem lies in the CODE sent by facebook. Specifically these lines in base_facebook.php:
if ($code && $code != $this->getPersistentData('code')) {
$access_token = $this->getAccessTokenFromCode($code);
...
protected function getAccessTokenFromCode($code, $redirect_uri = null) {
if (empty($code)) {
return false;
}
if ($redirect_uri === null) {
$redirect_uri = $this->getCurrentUrl();
}
...
Because CODE is issued for specific url sometimes there is such situation: Visitor arrives on www.example.com. He givies permissions and is redirected to example.com/login. But the code is not valid there, so the getUserAccessToken returns false. When you refresh the page you get same urls and everything's fine.
You're on the right track of not using getUser() because as I wrote above it's taken from the session if available.

Facebook redirect after login

I have read a number of questions and answers, including this one on StackOverflow and none works. My question to all responses I have seen are 'does it work in Safari?'.
I am trying to get this to work with Safari. It works on Chrome and Firefox fine. But in Safari the login screen just freezes and I get the "Unsafe JavaScript attempt to access frame with URL" log message.
I have a canvas app. I want to log the user in and redirect them to a page once they have logged in. I am trying to redirect directly after login. I have tried
setting window.top.location to a facebook url (with some data passed to a signed request as the all_data argument)
setting window.location to a URL with the same domain as my app.
subscribing to the auth.login event and putting the redirect there
putting the redirect in the callback to login
None of these works for Safari. I'm starting to think that there's no way to do it.
function doSomething()
{
FB.login(
function(loginResponse)
{
if (loginResponse.authResponse)
{
window.top.location = "my url"
}
},
{
scope:"some,scope"
}
);
}
}
In response to Nitzan Tomer, here is the equivalent code which doesn't work with Safari but does work with others:
function myThing()
{
FB.login(function(loginResponse)
{
if (loginResponse.authResponse)
{
FB.api('/me', function(response)
{
window.location = "http://my_app.com?x=" + response.xyz;
});
}
},
{
scope:"scopes"
}
);
}
This is not much of a solution to your problem, but more of a "workaround", though it still uses window.top.location but not from a callback so maybe it will work (I'm just not sure where the callback is executed, since it's the fb sdk that executes it, maybe they call it from the fb iframe inside your iframe).
Instead of using client side authentication, you can use the server side flow.
The entire process is happening on the top window, since it starts by you redirecting the user to the oauth dialog using window.top.location.
When the process ends facebook redirects the user to your redirect_uri, and there you can simply redirect the user where ever you want.
I hope this will help.
Also, you should be aware that in the Facebook Platform Policies it states:
13 . The primary purpose of your Canvas or Page Tab app on Facebook must not be to simply redirect users out of the Facebook experience
and onto an external site.
It turns out the problem was occurring slightly earlier in the login process and the callback never got called. I did set a breakpoint in the callback (which wasn't called) but I thought the breakpoint might not work for some reason (perhaps because it was being executed in the context of another window).
Anyway, the problem was that the channel file (which the docs seem to suggest are optional) wasn't working properly, and this caused a problem with Safari but not with other browsers.

Facebook getUser() function returning user ID after logout

I'm developing using the Facebook PHP SDK.
I wanted to make it so that when the user logs out of Facebook, they will automatically be logged out of my website too.
I am using the following code to detect the session, using the session cookie:
$facebook->getUser();
For some reason, the getUser() function still returns the user's Facebook ID, even after they have logged out of Facebook on their website.
Am I to detect the session first using another Function?
On the official documentation example here, is the following excerpt from their comments:
// Get User ID
$user = $facebook->getUser();
// We may or may not have this data based on whether the user is logged in.
//
// If we have a $user id here, it means we know the user is logged into
// Facebook, but we don't know if the access token is valid. An access
// token is invalid if the user logged out of Facebook.
This lead me to believe that the session cookie for Facebook would become unset upon Facebook logout?
Kind Regards,
Luke
I have the same issue!
The FB PHP SDK saves those things into the $_SESSION!
You can delete them like this when your user clicks logout:
$_SESSION['fb_'.APP_ID.'_user_id'] = '';
$_SESSION['fb_'.APP_ID.'_access_token'] = '';
Although this is not the final solution, it works for now.
I appreciate comments and solutions on that!
I want to give an alternative, in a way you don't have to handle session stuff. Although, I must warn you this is slower than cleaning up the session, because it relies on a new request. What we're doing in the code below is to check on Facebook if the token is still valid. Here it's:
try {
$facebook->api('/me','GET');
$logged = true;
} catch(FacebookApiException $e) {
$logged = false;
}
In my case, I was doing everything using the JavaScript SDK, so I couldn't clean session on logout. But in my landing page, I was needing a work around to check it before send the response back.
If you're facing something like this, definitely a good solution.
The problem seems to be in php-sdk in basefacebook.php at line 567
protected function getSignedRequestCookieName() {
return 'fbsr'.$this->getAppId();}
This method returns the name of the cookie the sdk is looking for. However, javascript-sdk uses 'fbs_' prefix. Change this to 'fbs_' and it works fine.
return 'fbs'.$this->getAppId();}
$facebook->destroySession();
To destroy the session you can also use:
$facebook->destroySession();

Best practice for dual-use iFrame + External authentication for Facebook enabled app

Okay, if cookies are a no-no, then I need a little guidance as to the best way to implement the application(s) that I'm creating.
The scenario is that I'm trying to create a single Asp.Net MVC application that can authenticate a user regardless of whether the user visits a site directly or via an iFrame in Facebook. There are separate actions (in separate controllers, actually) for getting INTO the app depending on whether the user enters via Facebook or not, but there are also places in the Facebook app where I'm opening up a new window to "extended" functionality in other areas of the application that can't really work well within the iFrame. It is supposed to transition seamlessly. It's currently working quite well using cookies, but I've from multiple sources that this is not a good thing for iFrame apps. However, I'm not sure exactly what this means.
Without cookies, can you still somehow get server-side access to the authentication token? If not, then what is the "right" way to handle this. Do I need to resort to manually parsing the token using the JS API and sending an AJAX notification to the server of the fact that the user is authenticated and create a forms auth token? Will the CanvasAuthorize attribute work without cookies? Right now I have added code to the FormsAuthentication_OnAuthenticate event in Global.asax to create the forms auth token if the user is logged in via Facebook (and properly associated with a valid user in the external app) as follows:
protected void FormsAuthentication_OnAuthenticate(Object sender, FormsAuthenticationEventArgs args)
{
if (FormsAuthentication.CookiesSupported)
{
if (Request.Cookies[FormsAuthentication.FormsCookieName] == null)
{
// Attempt to authenticate using Facebook
try
{
FacebookApp fbApp = new FacebookApp();
if (fbApp.Session != null)
{
dynamic me = fbApp.Get("me");
String fbID = "" + me.id;
MembershipUser mUser = AppMembershipProvider.GetUserByFacebookID(fbID);
if (mUser != null)
{
FormsAuthentication.SetAuthCookie(mUser.UserName, false);
AppMembershipProvider.UpdateLastLogin(mUser.UserName);
Session["FacebookLogin"] = true;
}
}
}
catch (Exception e)
{
Elmah.ErrorSignal.FromCurrentContext().Raise(e);
}
}
}
else
{
throw new HttpException("Cookieless Forms Authentication is not " +
"supported for this application.");
}
}
Will I need to change this?
Sorry if this is basic knowledge, but I'm confused as to how best to implement this. Thanks!
First, let me address the issue with the cookies. So, when I say to not use cookies in iFrames I am saying that for a couple reasons. First in IE, there are some security issues. You need to add the following header to your app to make cookies work correctly inside iframes:
P3P: CP="CAO PSA OUR"
The second big issue with cookies in iframe apps is Safari. Due to security settings in Safari, cookies cannot be created by iframes. As such, you will not be able to rely on cookies for authentication inside of iframes.
Give that you are using the app inside and outside of the iframe, you should have cookie support turned on. However, your app must be designed in a way that will work around the iframe issues. That is going to be the hard part.
The most reliable authentication inside iframe apps is the signed request method. What happens is facebook will append a query parameter to your url when the url is rendered inside the iframe. This query parameter contains the user's session. The Facebook C# SDK handles reading this for you, so you dont need to parse it etc. But you need to be aware that it is there. If you view the incoming request url of your iframe app in facebook you will see something like http://www.mysite.com/page/?signed_request={blahblahblah}.
So the key is that you need to make sure that if you are in the iframe you keep that ?signed_request value on the url.
You can do this several ways. First, you can use the CanvasRedirect methods. These are extension methods on System.Web.Mvc.Controller in the Facebook.Web.Mvc namespace. The canvas redirect uses javascript to redirect your page in the top url. This way Facebook is actually handling the redirects and will always add the signed_request to your iframe url. The problem for you is that this method of redirecting will only work in the iframe, not outside.
The second way would be to manually add the ?signed_request to the url when you redirect. You would do something like:
public ActionResult Something() {
return RedirectToAction("something", new { signed_request = Request.Querystring["signed_requets"]);
}
There are other ways also, like storing data in the session or something, but I wouldn't recommend going down that path.
What you are doing is definitely an advanced senario, but hopefully the above will help you get going in the right direction. Feel free to contact me directly if you have any questions. nathan#ntotten.com or #ntotten on twitter.
I am in a similar situation to you. What I do to handle the various situations that can arise is:
Enable cookies in both the C# and
JavaScript SDK.
Create a custom actionfilter that
inherits from
FacebookAuthorizeAttribute and
overrides the
HandleUnauthorizedRequest method to
redirect to either a connect
authorization page or an action
decorated with the
CanvasAuthorizeAttribute.
Pass either the signed_request
(canvas app) or auth_token (connect
app) as a querystring parameter to
everything.
Check for null sessions and oauth
tokens that don't match what has been
passed in the querystring.
The main point is to ensure that both the session and oauth tokens are valid. When inside Facebook the signed_request will ensure this is true. By passing the token from your connect auth page you can ensure you have a valid token to inject into the FacebookApp constructor.
public class FbAuthenticateAttribute : FacebookAuthorizeAttribute
{
private FacebookApp _fbApp;
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
base.OnActionExecuting(filterContext);
var accessToken = filterContext.HttpContext.Request.Params["access_token"];
if (FacebookApp.AccessToken != accessToken && !string.IsNullOrEmpty(accessToken))
{
_fbApp = new FacebookApp(accessToken);
}
else
{
_fbApp = FacebookApp;
}
filterContext.Controller.ViewBag.Context = GetContext().ToString();
filterContext.RequestContext.HttpContext.Response.AppendHeader("p3p", "CP=\"CAO PSA OUR\"");
try
{
dynamic user = _fbApp.Get("me");
var signedRequest = filterContext.HttpContext.Request.Params["signed_request"];
filterContext.Controller.ViewBag.QueryString = string.IsNullOrEmpty(signedRequest)
? "?access_token=" + _fbApp.AccessToken
: "?signed_request=" + signedRequest;
}
catch (Exception ex)
{
string url = GetRedirectUrl(filterContext);
filterContext.Result = new RedirectResult(url);
}
}
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
string url = GetRedirectUrl(filterContext);
filterContext.Result = new RedirectResult(url);
}
private string GetRedirectUrl(ControllerContext filterContext)
{
return new UrlHelper(filterContext.RequestContext).Action(GetRedirectAction(GetContext()), "Authentication");
}
private Enums.AppContext GetContext()
{
//Note: can't rely on this alone - find something more robust
return FacebookApp.SignedRequest == null ? Enums.AppContext.FBWeb : Enums.AppContext.FBApp;
}
private string GetRedirectAction(Enums.AppContext context)
{
return context == Enums.AppContext.FBWeb ? "ConnectAuthenticate" : "Authenticate";
}
}
It could definitely do with a refactor and still has problems but is the best solution I have found so far.