Extending Access Token Expiration not functioning - facebook-php-sdk

I am at the intermediate level in php and am new with facebook development. I have looked through the facebook documents and Stack Overflow previous comments.
All I basically wanted to do was let the user log in with their Facebook account and display their name.
My php page has a graph, and the page auto refreshes every 2 or 5 min.
I authenticate and get the facebook first_name to put on the page.
$graph = $facebook->api('/me');
echo $graph['first_name'] to get the first name of the user .. (for which I thought that no access token was required).
After about 90 min. I have been receiving the error:
fatal error: Uncaught OAuthException: An active access token must be used to query information about the current user......
and I have no value ( 0 ), in the $facebook->getUser(); parameter
I do know that off line access permission has been depreciated, (and I have have this enabled in my apps advanced settings)
I am trying to get an extended access token. In the FB docs. I see:
https://graph.facebook.com/oauth/access_token?
client_id=APP_ID&
client_secret=APP_SECRET&
grant_type=fb_exchange_token&
fb_exchange_token=EXISTING_ACCESS_TOKEN
I included my information in the link(an existing valid access token and all) and received a access token:
access_token=AAADbZBPuUyWwBAFubPaK9E6CnNsPfNYBjQ9OZC63ZBN2Ml9TCu9BYz89frzUF2EnLttuZAcG2fWZAHbWozrvop9bQjQclxVYle7igvoZCYUAg2KNQLMgNP&expires=4050
Yet this token expired in about 1 hour or so.(....expires=4050)
I assume I am using server side auth because I am using PHP?

I assume you need to enable "deprecate offline_access" in your Apps Advanced Settings page. As this worked for me:
//added code in base_facebook.php inside the facebook class
public function getExtendedAccessToken(){
try {
// need to circumvent json_decode by calling _oauthRequest
// directly, since response isn't JSON format.
$access_token_response =
$this->_oauthRequest(
$this->getUrl('graph', '/oauth/access_token'),
$params = array( 'client_id' => $this->getAppId(),
'client_secret' => $this->getAppSecret(),
'grant_type'=>'fb_exchange_token',
'fb_exchange_token'=>$this->getAccessToken(),
));
} catch (FacebookApiException $e) {
// most likely that user very recently revoked authorization.
// In any event, we don't have an access token, so say so.
return false;
}
if (empty($access_token_response)) {
return false;
}
$response_params = array();
parse_str($access_token_response, $response_params);
if (!isset($response_params['access_token'])) {
return false;
}
return $response_params['access_token'];
}
The token can still be invalid for several reasons, See How-To: Handle expired access tokens.
Hope it helps

There's a bug on this:
https://developers.facebook.com/bugs/241373692605971
But, another question on SO has a workaround (user uninstalls and re-installs):
fb_exchange_token for PHP only working once user removes app

Related

Ionic Storage doesn't update values

after I successfully log into my app using Firebase I want to store a bunch of information (like, user email, user uid, user name...) and use it throughout my app. The best way I found for this is to use Ionic Storage.
Now, in the first login works fine, but If I log out and log in with another user, the first user info is still showing instead of the new one. Note that I am cleaning all my storage when the user hits log out. My code:
Auth validation (guard): I am checking user auth status again after login.
return this.AFauth.authState.pipe(map(auth => {
if (auth !== null && auth !== undefined) {
this.saveUserInStorage(auth);
return true;
} else {
this.router.navigate(['/home']);
return false;
}
}))
Saving Firebase info in Storage
saveUserInStorage(auth) {
this.storage.ready().then(() => {
this.storage.clear(); //cleaning again just in case...
this.storage.set('user_uid', auth.uid);
this.storage.set('user_name', auth.displayName);
this.storage.set('user_email', auth.email);
this.storage.set('user_photoUrl', auth.photoUrl);
}).catch(err => {
console.log('no pudimos guardar');
});
}
Logout function
logOutUser() {
firebase.auth().signOut().then(result => {
// after user hits logout, I erase my storage
this.storage.remove('user_email');
this.storage.clear();
this.router.navigate(['/home']);
}).catch(error => {
console.log(error);
// An error happened.
});
}
I have to reload my webpage to see the last user logged in.
This might not have anything to do with your storage but rather you have to reset your forms or fields where the information is shown or change the way this information is loaded. I would suggest two options:
On the pages use ionViewWillEnter and put the code in there where the information is pulled out of the storage. (this is probably the easiest)
Use BehaviorSubjects for always emitting a new event when the info is changed and listen to those events where the information is used.
The reason for this is, that every page, once created won't create itself again. You can see this if you console Log something in ngOnInit. Therefore your old information sticks to the page until you find another way to update it. (with ionViewWillEnter or Observables)

Firebase service account to generate authentication token for client-side use with Google Apps Script

I am having difficulty using the FirebaseApp (a 3rd party API) to generate an authentication token that can be passed to a sidebar and used by the client to login and access my Firebase Database client-side.
I'm trying to use this tutorial but cannot get it working without using a database secret (which is being depreciated) in makeToken(). I'd prefer to use a service account as reflected in this tutorial. When I look at the difference between the tokens generated, the first 2 pieces separated by a '.' are identical, the last piece after the final '.' is different. The lengths are the same as well. eg:
//Example Generated by Database Secret: TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBv.ZGdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=.dGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2U=
//Example Generated by Service Account: TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBv.ZGdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=.IHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbml=
I can generate the OAuth access token, pass it to FirebaseApp and generate an authentication token, but when it is passed client-side and I attempt to authenticate I get an error: Login Failed! Error: INVALID_TOKEN: Failed to validate MAC.
It seems like there is a lot of misinformation and conflicting information on how this should be done.
I have a getFirebaseService() function server-side that uses Apps Script OAuth2 Library to get an access token.
function getFirebaseService() {
return OAuth2.createService('Firebase')
// Set the endpoint URL.
.setTokenUrl('https://accounts.google.com/o/oauth2/token')
// Set the private key and issuer.
.setPrivateKey(fb_PRIVATE_KEY) //Service account private key
.setIssuer(fb_SERVICE_EMAIL) //Service account email
// Set the property store where authorized tokens should be persisted.
.setPropertyStore(PropertiesService.getScriptProperties())
// Set the scopes.
.setScope('https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/firebase.database');
}
I have a makeToken() function server-side that gets an authentication token from Firebase using the OAuth access token. I am able to use the service.getAccessToken() OAuth token server-side to access and store data. So that works, I guess my issue is creating a client auth token that's more restrictive.
function makeToken(){
var service = getFirebaseService();
if (service.hasAccess()) {
return FirebaseApp.getDatabaseByUrl(fb_URL, service.getAccessToken()) //Database Secret Works: "AAslhfi3MYACCESSTOKEN2930hf03ah4th8" but is being depreciated.
.createAuthToken(Session.getActiveUser().getEmail());
} else {
Logger.log("makeToken: " + service.getLastError());
}
}
Then client-side, from the sidebar, I try to authenticate with a custom auth token retrieved server-side from makeToken().
var userAuthToken;
google.script.run.withSuccessHandler(function (requestAuthToken) {
userAuthToken = authenticateClient(requestAuthToken)
}).makeToken();
function authenticateClient(userRequestToken) {
var ref = new Firebase(fb_URL);
ref.authWithCustomToken(userRequestToken, function (error, authData) {
if (error) {
console.log("FB Login Failed!", error); //Error below come from here.
}
else {
console.log("FB Login Succeeded!", authData);
}
});
return ref.authData.auth;
}
This results in Login Failed! Error: INVALID_TOKEN: Failed to validate MAC..
Edit: Is it possible FirebaseApp is incorrectly generating the JWT Authentication Token?
Edit2: I think the above edit is unlikely as I attempted to use the GSApp library and had the same issue. It only seems to want the depreciated database secret, not a service account OAuth.
Alright, so after a very long day I figured it out. I'm going to lay out what I ended up using for libraries and what the issue was (see the third library). The main problem was essentially that the tutorial was outdated and no a lot of people use Firebase in apps script.
OAuth2 (Server-side)
Link
I didn't have to change anything here! It was working fine and never an issue.
FirebaseApp (Server-side)
Link
This is a nice library and I stuck with it because it worked well (once I got it there). I had to make a change to my original code that came from the tutorial I mentioned. My code ended up like this and worked:
if (service.hasAccess()) {
return FirebaseApp.getDatabaseByUrl(fb_URL, service.getAccessToken()) //get OAuth Token
.createAuthToken(Session.getEffectiveUser().getEmail(), null, serviceAccount.client_email, serviceAccount.private_key);
//... Added the null, private key, and service email parameters.
Firebase (Client-side)
Link
Alright, so this is where my main issue was -- The tutorial I followed for client-side setup was old. I had to upgrade the code on my own to use the new 3.x version:
<script src="https://www.gstatic.com/firebasejs/5.8.2/firebase.js"></script>
// Initialize Firebase
var config = {
apiKey: "<Web API Key>",
authDomain: "<Project ID>.firebaseapp.com",
databaseURL: "https://<DB URL>.firebaseio.com/"
};
firebase.initializeApp(config);
With this firebase instance I was able to update my original authenticateClient() method:
function authenticateClient(userRequestToken) {
firebase.auth().signInWithCustomToken(userRequestToken).catch(function(error) {
// Handle Errors here.
console.error("authClient: ", error.code, error.message);
});
return {
uid: firebase.auth().currentUser.uid,
metadata: {
lastSignInTime: firebase.auth().currentUser.lastSignInTime
}
};
}
That's it! I now have a firebase instance with a signed in user via JWT Custom Token! I came across a few people with similar issues an I hope this helps.

Firebase Web Admin

First of all, I am using nodejs for the backend. I use firebase hosting and firebase functions to deploy an express() app.
What I am trying to achieve is to make an admin website, which is connected to Firebase. so I have a route /admin/ like this:
adminApp.get("/", (request, response) => {
return response.redirect("/admin/login");
});
Here I basically want to check if a current user is logged in - or not.
I know firebase supports client side authentication using:
firebase.auth().onAuthStateChanged(user => {
if (user) {
} else {
}
});
And using
function login() {
var userEmail = document.getElementById("email").value;
var userPass = document.getElementById("password").value;
firebase.auth().signInWithEmailAndPassword(userEmail, userPass).catch(function(error) {
var errorCode = error.code;
var errorMessage = error.message;
if (error) {
document.getElementById('loginError').innerHTML = `Error signing in to firebase`;
}
});
}
However image this case:
Someone (not an admin) is visiting /admin/some_secret_website/ which he obviously does not have access to.
If I rely on client side authentication, it first loads the entire website and the scripts and then notices - hey I am not authenticated, let me redirect to /login. By then however anyone knows the source code of an admin page.
I'd rather have something like:
adminApp.get("/admin/some_secret_website", (request, response) => {
if (request.user) {
// user is authenticated we can check if the user is an admin and give access to the admin page
}
});
I know that you can get the user's token and validate that token using the AdminSDK, but the token must be send by the client code, meaning the website was already loaded.
I came across Authorized HTTPS Endpoint by firebase, but it only allows a middleware when using a bearer token.
Does anybody know how I can maintain a server side user object to not even return admin html to the browser but only allow access to admins?
Like Doug indicated, the way your admin website/webapp would function with Firebase Cloud Functions (which is effectively a Nodejs server) is that you get the request, then use the headers token to authenticate them against Firebase Auth. See this answer for a code snippet on this.
In your case, I'm thinking you would create a custom claim for an "administrator" group and use that to determine whether to send a pug templated page as a response upon authentication. As far as Authorization, your db rules will determine what said user can CRUD.

How to get user access token using LinkedIn Javascript API like in Facebook?

I am developing a native Mobile App and what i need is to pass a users's access token and get user details for doing mobile based operations. I was able to achieve the same in Facebook. But how can i get the access token of user via LinkedIn JavaScript API.
Facebook API way:
function statusChangeCallback(response) {
// The response object is returned with a status field that lets the
// app know the current login status of the person.
// Full docs on the response object can be found in the documentation
// for FB.getLoginStatus().
if (response.status === 'connected') {
// Logged into your app and Facebook.
console.log(response); ===> GOT USER ACCESS TOKEN FROM THIS RESPONSE
testAPI();
} else if (response.status === 'not_authorized') {
// The person is logged into Facebook, but not your app.
document.getElementById('status').innerHTML = 'Please log ' +
'into this app.';
} else {
// The person is not logged into Facebook, so we're not sure if
// they are logged into this app or not.
document.getElementById('status').innerHTML = 'Please log ' +
'into Facebook.';
}
}
Any help to get the same in LinkedIn will be very much appreciated.
Check out the LinkedIn's Documentation on Exchanging JSAPI tokens for OAuth tokens.

PHP SDK: How do I capture the access token after user auths app?

This is for a canvas app on the Facebook Platform using the new(est) Facebook PHP SDK.
We are using the PHP example from the Facebook tutorial (https://developers.facebook.com/docs/appsonfacebook/tutorial/) to trigger the OAuth dialog and get the test user to the redirect URL.
At the redirect URL, we use the PHP example from the Facebook signed request docs page (https://developers.facebook.com/docs/authentication/signed_request/) and our test users can successfully authorize the app.
However, after the test user auths the app, we are not able to capture the access token and its expiration. We can see it in the address bar appended to the redirect URL, but it does not show up in the $_REQUEST array. If we add {$access_token = $facebook->getAccessToken();} to the redirect URL page, it shows a value for the access token, but the value it shows is not the full token string that we see when we click on Show Token in the Test User Roles page (which we believe is the correct access token for the test user).
Here is an example of the redirect URL with an access token appended:
http://karmakorn.com/karmakorn/alpha20/kk-fb-auth.php#access_token=126736467765%7C2.AQDavId8oL80P5t9.3600.1315522800.1-100002908746828%7CJICJwM1P_97tKmqkEO5pXDCf-7Y&expires_in=6008
Here is what var_dump shows for the $REQUEST array for that same page:
array(3) { ["_qca"]=> string(26) "P0-709927483-1291994912966" ["__switchTo5x"]=> string(2) "30" ["PHPSESSID"]=> string(26) "euois02ead39ijumca7nffblh2" }
We have no idea why the $_REQUEST array varies from the values appended to the URL, and more importantly -- how to capture the access token and its expiration date.
Can someone show us a working example of how they capture this data after running the parse_signed_request($signed_request, $secret) function on the redirect page? Thanks!
ADDITIONAL INFO:
Here is the pertinent code from A) our test index page, and B) our test redirect page. If we use our text index page as the redirect url it gets stuck in an endless loop -- because the user is never identified.
A) Index Page
// Create kk-fb app instance
$facebook = new Facebook(array(
'appId' => KKFB_ID,
'secret' => KKFB_KY,
'oauth' => true,
));
$app_id = KKFB_ID;
$secret = KKFB_KY;
$canvas_auth = 'http://karmakorn.com/karmakorn/alpha20/kk-fb-auth.php';
$auth_url = "https://www.facebook.com/dialog/oauth?"
. "client_id=" . $app_id
. "&redirect_uri=" . urlencode($canvas_auth)
. "&response_type=token"
. "&scope=email,publish_stream";
$signed_request = $_REQUEST["signed_request"];
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
$data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true);
if (empty($data["user_id"])) {
echo("<script> top.location.href='" . $auth_url . "'</script>");
} else {
echo ("Welcome User: " . $data["user_id"]);
}
B) Redirect Page
// Create kk-fb app instance
$facebook = new Facebook(array(
'appId' => KKFB_ID,
'secret' => KKFB_KY,
'oauth' => true,
));
$app_id = KKFB_ID;
$secret = KKFB_KY;
$signed_request = $_REQUEST["signed_request"];
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
$data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true);
$user = $facebook->getUser();
$access_token = $facebook->getAccessToken();
echo "User: $user <br>";
echo "Access Token: $access_token <br>";
echo "Signed Request: $signed_request <br>";
var_dump($_REQUEST);
Here is what shows up as these echo results:
User: 0
Access Token: 126736467765|**SECRET**
Signed Request:
array(3) { ["_qca"]=> string(26) "P0-709927483-1291994912966" ["_switchTo5x"]=> string(2) "30" ["PHPSESSID"]=> string(26) "frugi545cdl15gjind1fnv6pq1" }
Interestingly, when the test user goes back to the index page the if condition is satisfied and we can get the correct access token:
Welcome User: 100002908746828
Access Token: 126736467765|2.AQBgcyzfu75IMCjw.3600.1315544400.1-100002908746828|m5IYEm976tJAkbTLdxHAhhgKmz8
Obviously, we are still missing something!? Also, we need to learn how to get the expiration time as a variable too so we can store both of these in our database.
OK, let's try this again.
Server-side vs Client-side Authentication
You are exclusively using the PHP SDK, so you want to do server-side authentication, where the authentication code is sent to the server over HTTP via the URL. This will allow you to fetch an access token for the user on the first page load after auth (in your case, the redirect page). The auth_url you are currently constructing is setting response_type=token, which forces the redirect to use client-side auth mode and set the token in the URL fragment instead of in the query. You should remove that parameter completely. In fact, I highly recommend you just use the PHP SDK instead of constructing that URL yourself. See example below.
Application Access Tokens
The odd-looking access token 126736467765|SECRET is your application access token, which is composed of your app ID and secret key. The application access token is returned by getAccessToken() if no user access token is available (because some API calls require at least some sort of access token). This also means that you've revealed your secret key to the world via this blog post, so you should reset your app secret otherwise anyone will be able to make API calls on your behalf. I highly recommend you elide parts of your access tokens if you share them with others.
Token Expiration
The OAuth 2.0 flow and v3.1.1 of the PHP SDK don't make determining the expiration time of a token all that easy. I would suggest attempting to make the API call, and then refreshing the token if the API call fails with an OAuthException. Tokens can be invalid even if they haven't expired, so this deals with more cases. However, if you still want to maintain the expiration date on your end, you might just want to extract it from the token itself. If you have an expiring token, then the expiration timestamp will be contained within that string. Here's a function I put together quickly to extract that:
function extractExpirationFromToken($access_token) {
$segments = explode('|', $access_token);
if(count($segments) < 2) { return 0; }
$segments = explode('.', $segments[1]);
if(count($segments) < 4) { return 0; }
$expires = $segments[3];
$dash_pos = strrpos($expires, '-');
if($dash_pos !== false) {
$expires = substr($expires, 0, $dash_pos);
}
return $expires;
}
New Index Page Code
// Create kk-fb app instance
$facebook = new Facebook(array(
'appId' => KKFB_ID,
'secret' => KKFB_KY,
));
$canvas_auth = 'http://karmakorn.com/karmakorn/alpha20/kk-fb-auth.php';
$auth_url = $facebook->getLoginUrl(array(
'scope' => 'email,publish_stream',
'redirect_uri' => $canvas_auth, // you could just redirect back to this index page though
));
$user = $facebook->getUser();
if (empty($user)) {
echo("<script> top.location.href='" . $auth_url . "'</script>");
} else {
echo ("Welcome User: " . $user);
}
Redirect Page
I don't think you need this page at all. You could just redirect the user back to your original index page.
// Create kk-fb app instance
$facebook = new Facebook(array(
'appId' => KKFB_ID,
'secret' => KKFB_KY,
));
$user = $facebook->getUser();
$access_token = $facebook->getAccessToken();
// also copy the function definition given earlier
$expiration = extractExpirationFromToken($access_token);
echo "User: $user <br>";
echo "Access Token: $access_token <br>";
echo "Expiration: $expiration <br>";
echo "Request: <br>";
var_dump($_REQUEST);
You can use the facebook build in method getAccessToken() for example;
$access_token = $facebook->getAccessToken();
This will give you the access token to your variable, now if you are getting it empty, remember to first check if the fuid is being properly catch, if it isn't you might need to review your settings be sure your "App Domain" is set this part is very important after setting it correctly you need to reset your app secret, then set your new values in your auth code. Hope this help, let me know :)
pd. Also remember to keep the scope of your variables visible in your whole php file or class.
Problem
The access_token in your pasted URL is not part of the query string, but instead contained in the URL fragment (after the #). URL fragments are not sent to the web server, and are readable only by client-side code like Javascript. Therefore the PHP SDK only sees http://karmakorn.com/karmakorn/alpha20/kk-fb-auth.php, which is why $_REQUEST does not contain an access_token key.
Questions / Notes
What are you using for your redirect_uri? I think you want to be using something like http://apps.facebook.com/your_canvas_url/
You shouldn't need to call parse_signed_request yourself or copy any code from the signed request page. The PHP SDK will do that for you. Just call:
$facebook = new Facebook(array(
'appId' => '…',
'secret' => '…',
));
$access_token = $facebook->getAccessToken();
Possible solutions
Also use the Facebook Javascript SDK. You can start by adding its <script> tag in your destination page (kk-fb-auth.php) (see the docs for full details; don't forget to set oauth: true). The JS SDK should set a cookie (named fbsr_126736467765) which the PHP SDK will be able to read via $_REQUEST or $_COOKIE on subsequent page loads.
If you want to do this with PHP, you can get the user's access token with a separate call to the Graph API at your redirect_uri. For this you need to change the response_type of your $auth_url in your index page to "code" or "code token".
Then, at your redirect page, Facebook will add a "code" parameter in the querystring. This API call will return you the full access_token and expiration time:
https://graph.facebook.com/oauth/access_token?
client_id=YOUR_APP_ID&
redirect_uri=YOUR_URL&
client_secret=YOUR_APP_SECRET&
code=$_REQUEST['code']
For more information you can refer to the docs on authentication.

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