I would like to add a new option to my application that allows users to post images to their Facebook albums or on the wall. As of now, the most unclear point is how to organize authorizaton process in the DESKTOP application. Official documentation says that I can use short-lived or long-lived access tokens. There is no any issue with getting short-lived access tokens, but I want my application to ask a user for login/password rarely.
I see 2 possible options.
1) Use short-lived access tokens
When a previous token has expired, I need to ask Facebbok for a new one, but for that I need user's login/password.
Questions:
1.1) Is it a good idea to store and encrypt somewhere on disk user's login/password and to ask Facebook for a new short-lived access token using user's credentials in the background (i.e. user won't see login form - this is hidden) ?
1.2) Is it a good idea to store and encrypt short-lived access token on disk to reuse it if a user just restarted application and token is still valid?
2) Use long-lived access tokens
This would be ideal for me. Even if access token has expired after 60 days, my desktop app will ask for a new one.
Questions:
2.1) Is it possible to get long-lived access token by DESKTOP application directly from Facebook? Is it needed to implement additional Web service for getting such token (I know that just server (not client app) can add app secret to request for long-lived token)?
2.2) Even if I able to get long-lived token from the Facebook directly, is it a good idea to store and encrypt it somewhere on disk for further reusage? How apps usually story it?
I will appreciate any HELP!!!
I am creating a system to allow our clients to create articles and post them in our CMS. The one feature we are being asked to implement is that when an editor publishes an article, that that article gets posted to the company's facebook wall as well.
The tricky part to this is that the people who are allowed to publish articles may not have login credentials to the company's overall FB account. This means that I can't rely on the normal process to retrieve access tokens for accounts (or so it seems).
I did quite a bit of research and came up with the following documentation sources:
http://developers.facebook.com/docs/howtos/login/extending-tokens/
http://developers.facebook.com/docs/howtos/login/server-side-login/
http://developers.facebook.com/docs/concepts/login/login-architecture/
http://developers.facebook.com/roadmap/offline-access-removal/
From these it seems that in order to allow locally authorized users to post to the company's facebook wall I must:
Have a user with valid FB credentials log into an Admin page
Click a button to start the authorization process
Retrieve the short term access token from the FB response and exchange it for a long-lived 60 day token
Store the 60 day token in our database
Each time a user attempts to publish an article, test if the token has expired and if so alert the admin they need to re-authorize.
Is this the only workflow to accomplish this or is there a simpler method, preferably one that does not require the last step.
Use a page token. Get it using a long-lived user access token – then the page token will not expire by default.
Currently I have a option in my web page such that, on-clicking a button, Facebook login authentication dialog will be poped up as explained in http://developers.facebook.com/docs/authentication/#server-side-flow. I am using JavaScript SDK (FB.api) for this.
So on users successful authentication and app authorization, I will retrieve an ACCESS TOKEN for that particular user from the response. To avoid token expiration, I am using OFFLINE_ACCESS. Finally the token is saved in my local database and a cron job will use this token periodically to read users Facebook datas.
My problem is, as Facebook is going to deprecate the offline_access, is there any other way to have unique ACCESS TOKEN for a user (with out expiration time), such that the users will approve my app once and the cron job will use their token to read data on regular basis.
From this link: http://developers.facebook.com/roadmap/offline-access-removal I found that we can only extend the token expiration time.
Can anyone please suggest a solution for this?
As I understand it, this is the basic process for new Facebook iframe canvas apps using the OAuth2 API in a nutshell:
Redirect to (or have user click link to) app's authorization URL
User authorizes and is redirected to your callback URL
Callback uses "code" parameter to get a access token
Access token is used with Graph API to pull or push information
The problem is that access tokens expire relatively quickly and need to be "refreshed", so my questions are 1) how do you detect that the token has expired aside from trying to use it and simply getting an error? and 2) what is the best practice for obtaining a new token?
Currently, I just detect that there was an error trying to get the user's information with their access token, then redirect to the authorization URL again -- since they already authorized the app a blank page flashes by and they are redirected back to my app callback where I get a fresh token. It's so clunky I can't believe this is the proper method.
The only way to tell if a cookie is valid is to use it and catch the error if it is expired. There is no polling method or anything to check if a token is valid.
To get a new token, simply redirect the user to the authentication page again. Because they have already authorized your app they will instantly be redirected back to your app and you will have a new token. They won't be prompted to allow since they have already done that.
In short, there are no tricks to this. You are already doing it correctly.
Recently, facebook has made some changes to access tokens which allows them to be refreshed periodically.
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
For more details, check here: https://developers.facebook.com/docs/roadmap/completed-changes/offline-access-removal
//you just need more step because the access token you are getting will expire in 1 hour
//you can overcome this in step 5
1-Redirect to (or have user click link to) app's authorization URL
2-User authorizes and is redirected to your callback URL
3-Callback uses "code" parameter to get a access token
4-Access token is used with Graph API to pull or push information
5-exchange short-lived access token you just got with 60 day access token
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
6-after 60 day the user must login again to your app and the steps from 1-5 will be repeated.
--the real problem you will face is how to make the user visit your app page again
Facebook has removed the feature of refresh the access token on the "behalf of" mode. The best and easy way is to redirect the user to facebook login page to re-oauth the app.
Find facbook doc here
if user has already authorized your application and access token expired. you can redirect user to authentication page again. but oauth dialog doestn't show because user already authorized your application. he will redirect to redirect_url parameter you used.
I am playing around with the Oauth 2.0 authorization in Facebook and was wondering if the access tokens Facebook passes out ever expire. If so, is there a way to request a long-life access token?
After digging around a bit, i found this. It seems to be the answer:
Updated (11/April/2018)
The token will expire after about 60 days.
The token will be refreshed once per day, for up to 90 days, when the person using your app makes a request to Facebook's servers.
All access tokens need to be renewed every 90 days with the consent of the person using your app.
Facebook change announce (10/04/2018)
Facebook updated token expiration page (10/04/2018)
offline_access:
Enables your application to perform authorized requests on behalf of the user at any time. By default, most access tokens expire after a short time period to ensure applications only make requests on behalf of the user when the are actively using the application. This permission makes the access token returned by our OAuth endpoint long-lived.
Its a permission value requested.
http://developers.facebook.com/docs/authentication/permissions
UPDATE
offline_access permission has been removed a while ago.
https://developers.facebook.com/docs/roadmap/completed-changes/offline-access-removal/
Try this may be it will help full for you
https://graph.facebook.com/oauth/authorize?
client_id=127605460617602&
scope=offline_access,read_stream,user_photos,user_videos,publish_stream&
redirect_uri=http://www.example.com/
To get lifetime Access Token you have to use scope=offline_access
Meaning of scope=offline_access is that :-
Enables your application to perform authorized requests on behalf of
the user at any time. By default, most access tokens expire after a
short time period to ensure applications only make requests on behalf
of the user when the are actively using the application. This
permission makes the access token returned by our OAuth endpoint
long-lived.
But according to facebook future upgradation the offline_acees functionality will be deprecated for forever from the 3rd October, 2012.
and the user will be given 60 days long-lived access token and before expiration of the access token Facebook will notify or you can get your custom notification functionality fetching the expiration value from the Facebook Api..
Note that Facebook is now deprecating the offline_access permission in favor of tokens for which you can request an "upgrade" to the expiry. I'm just now dealing with this, myself, so I don't have much more to say, but this doc may help:
https://developers.facebook.com/docs/offline-access-deprecation/
I came here with the same question as the OP, but the answers suggesting the use of offline_access are raising red flags for me.
Security-wise, getting offline access to a user's Facebook account is qualitatively different and far more powerful than just using Facebook for single sign on, and should not be used lightly (unless you really need it). When a user grants this permission, "the application" can examine the user's account from anywhere at any time. I put "the application" in quotes because it's actually any tool that has the credentials -- you could script up a whole suite of tools that have nothing to do with the web server that can access whatever info the user has agreed to share to those credentials.
I would not use this feature to work around a short token lifetime; that's not its intended purpose. Indeed, token lifetime itself is a security feature. I'm still looking for details about the proper usage of these tokens (Can I persist them? How do/should I secure them? Does Facebook embed the OAuth 2.0 "refresh token" inside the main one? If not, where is it and/or how do I refresh?), but I'm pretty sure offline_access isn't the right way.
Yes, they do expire. There is an 'expires' value that is passed along with the 'access_token', and from what I can tell it's about 2 hours. I've been searching, but I don't see a way to request a longer expiration time.
since i had the same problem - see the excellent post on this topic from ben biddington, who clarified all this issues with the wrong token and the right type to send for the requests.
http://benbiddington.wordpress.com/2010/04/23/facebook-graph-api-getting-access-tokens/
You can always refresh the user's access token every time the user logs into your site through facebook.
The offline access can't guarantee you get a life-long time access token, the access token changes whenever the user revoke you application access or the user changes his/her password.
Quoted from facebook http://developers.facebook.com/docs/authentication/
Note: If the application has not requested offline_access permission, the access token is time-bounded. Time-bounded access token also get invalidated when the user logs out of Facebook. If the application has obtained offline_access permission from the user, the access token does not have an expiry. However it gets invalidated whenever the user changes his/her password.
Assume you store the user's facebook uid and access token in a users table in your database,every time the user clicks on the "Login with facebook" button, you check the login statususing facebook Javascript API, and then examine the connection status from the response,if the user has connected to your site, you can then update the access token in the table.
Hit this to exchange a short living access token for a long living/non expiring(pages) one:
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
log into facebook account and edit your application settings(account -> application setting ->additional permission of the application which use your account). uncheck the permission (Access my data when I'm not using the application(offline_access)). Then face will book issue a new token when you log in to the application.
Basic the facebook token expires about in a hour. But you can using 'exchange' token to get a long-lived token
https://developers.facebook.com/docs/facebook-login/access-tokens
GET /oauth/access_token?
grant_type=fb_exchange_token&
client_id={app-id}&
client_secret={app-secret}&
fb_exchange_token={short-lived-token}
This is a fair few years later, but the Facebook Graph API Explorer now has a little info symbol next to the access token that allows you to access the access token tool app, and extend the API token for a couple of months. Might be helpful during development.
check the following things when you interact with facebook graph api.
1) Application connect URL should be the base of your "redirect_uri"
connect URL:- www.x-minds.org/fb/connect/
redirect_uri - www.x-minds.org/fb/connect/redirect
2) Your "redirect_uri" should be same in the both case (when you request for a verification code and request for an access_token)
redirect_uri - www.x-minds.org/fb/connect/redirect
3) you should encode the the argument when you request for an access_token
4) shouldn't pass the argument (type=client_cred) when you request for an access_token. the authorization server will issue a token without session part. we can't use this token with "me" alias in graph api. This token will have length of (40) but a token with session part will have a length of(81).
An access token without session part will work with some cases
eg: -https://graph.facebook.com/?access_token=116122545078207|EyWJJYqrdgQgV1bfueck320z7MM.
But Graph API with "me" alias will work with only token with session part.
I don't know when exactly the tokens expire, but they do, otherwise there wouldn't be an option to give offline permissions.
Anyway, sometimes requiring the user to give offline permissions is an overkill. Depending on your needs, maybe it's enough that the token remains valid as long as the website is opened in the user's browser. For this there may be a simpler solution - relogging the user in periodically using an iframe: facebook auto re-login from cookie php
Worked for me...