I have an application that used to use offline_access, which obviously needs changing since that's going away.
We use this permission to publish messages to the facebook wall of a user when they interact without our backend through any number of APIs. We have a website, several mobile applications on iPhone, Android, Blackberry, and Nokia phones that connect to the application, as well as a desktop application that interfaces with hardware devices and all of these can cause the backend to attempt to publish to facebook, but only the website allows the user to make the initial authorization with facebook.
From what I understand, using server-side authentication gets 60 day long tokens, and the only way to get new tokens is to redo the authentication process which assuming the user hasn't changed password, is logged into facebook, and hasn't de-authorized the application will appear as nothing but a series of automated redirects.
Is there any other way to do this? For example, what exactly does fb_exchange_token do? Is it applicable in this case or does this ONLY apply to tokens received via the javascript API?
Is there anything we can do for these non-website user interfaces aside from incorporate the native facebook APIs and do the same thing for as the website?
Attempting to use fb_extend_token was pretty fruitless. Rerunning the standard authentication returned the same token but with a fresh 60 day expiry time. Doing it again a short while later didn't extend the token. I'm hoping this means I can only do this once a day, not once per token.
Since I was using the server-side flow and the keys would never be seen by the user I was able to rework my app slightly to use my APPLICATION token. These keys belong to your app and allow you to use the API on behalf of a user for as long as they haven't revoked their permission. The user authorization tokens can expire, but as long as the user hasn't explicitly removed your app from the apps they've allowed, your token will continue to allow you to post to the wall using a /user/ URL, the /me/ URLs won't work because your token is bound to your app.
I believe once the deprecation of offline_access is complete, obtaining/exchanging access tokens is the only way to do what you need.
Anyone who had offline access before the deprecation will still be able to use your application normally, for 60 days at least. Once this period is over, you have to re authorize users and extend their access tokens for another 60 days. To do this you have them log in, and authorize your app (if necessary). Then you extend their access token using fb_exchange_token, so it is good for 60 days.
I'm sure you have seen it, but it's all outlined in this article, more specifically the section about previously using offline_access. I also found this post useful for doing an upgrade. Here is another link that further details how to deal with invalid tokens.
Related
Should the limited login store the access token for future session?
I'm transferring my iOS app from classic login to limited login. But I can't get the auto-re-login to work.
Re-login with classic works correctly as docs says. "The FBSDKLoginManager sets this token for you and when it sets currentAccessToken it also automatically writes it to a keychain cache." The app r-logins correctly.
But with limited login it seems it doesn't store the token. Should is store? The docs are unclear whether limited login should do this or not.
Best, Hu
Let's start with some points to proceed:
Limited Login mode doesn't provide you an Access Token. It provides you an Authentication Token. It's a regular JWT you can parse, but you are not able to use it for FB Graph API requests;
You can get the basic information about the user just by decoding this Authentication Token or using FB SDK right after signing in;
Currently, this token has an expiration of 1 hour, but you don't really need to refresh it every hour unless you need to get an update of the user information (for instance, to fetch a changed name, email, or a list of friends);
As you can see in the official blog post of Facebook, to refresh a token with information inside it, you need to re-authenticate a user, so call an SDK method to show FB popup. Reference: FB: Announcing expanded functionality in Limited Login
Currently, the official documentation is really unclear and has just a couple of pages related to the Limited Login mode. So if you still have any other questions, feel free to ask, I'll update the post.
I am the administrator of a Facebook Page. I am building a web app which, under certain circumstances, will post on Facebook as that Page.
With most APIs, I would just get an API key, and supply that when connecting to the API from my app. But Facebook expects an access token instead of an API key. (Specifically, in this case, it needs a "page access token".)
I am trying to figure out how to get a page access token that will be as permanent as possible.
After jumping through a bunch of esoteric, undocumented hoops (see here and here) in order to get a token that wouldn't expire, I had this working. When I ran the token through Facebook's Access Token Debugger, the "Expires" field read "Never". All was good in the world.
But, the next day, my token became invalid anyway. The Access Token Debugger, and my app's calls to Facebook's PHP SDK, both started returning this error:
Error validating access token: Session does not match current stored session. This may be because the user changed the password since the time the session was created or Facebook has changed the session for security reasons.
It seems that a token can become invalid for a variety of reasons (but this article is five years old, so who knows – Facebook changes things every two weeks). I had not changed my password. (I might have logged out of Facebook, though.) Facebook offers no specifics about why this particular token might have become invalid.
I've also seen a few references to a permission called offline_access, but Facebook seems to have removed this.
I suppose my question is twofold:
In general, I've found Facebook token authentication to be incredibly brittle when calling the Facebook API from the server. The token system seems to be designed mainly to allow other users to grant (or revoke) various kinds of account access to my apps. But that's not what I'm doing – I'm trying to get a token that will let me post to a page that I own. And for that scenario, Facebook's aggressive invalidation of tokens becomes a serious liability. I can't launch my app if my access token (and therefore my Facebook integration) could randomly stop working at any moment, requiring me to generate a new token and update the app. This seems absurd. Is there an alternative method of authenticating to Facebook for my purposes?
If a page access token is, in fact, the best way to authenticate my app to Facebook in order to post as my Page: how can I ensure that my token doesn't spontaneously become invalid?
I hate developing for Facebook :/ Thanks for any insight you can offer.
Extended Page Tokens are valid forever. They only get invalidated if you change your password or if you change the App Secret of your App. There´s really no magic in it, checking if the Token is still valid is obviously not a bad idea but that´s up to you. For example, you can send yourself an automated Email when there is an error using the Token, so you can refresh it. But it will really just happen if you change your password.
Links:
https://developers.facebook.com/docs/facebook-login/access-tokens
http://www.devils-heaven.com/facebook-access-tokens/
I'm storing long-lived access tokens for users of my application that have associated their Facebook accounts to it. Since the demise of the offline_access tokens, these long-lived tokens have an expiry date of "about 60 days." However, they can refresh themselves when the user interacts with Facebook. According to the documentation:
These tokens will be refreshed once per day when the person using your app makes a request to Facebook's servers. If no requests are made, the token will expire after about 60 days and the person will have to go through the login flow again to get a new token.
What I'd like to know is what constitutes making a request to Facebook's servers. Does the user have to log in to the Facebook website, mobile app, or use a Like button somewhere? Or does my application making a request on behalf of the user count as well?
Also, when the tokens are refreshed, are they refreshed for another 60 days? Or are they refreshed for a smaller duration?
I wasn't able to find these specific answers in the documentation or in other questions asked here, so thanks in advance to anyone who might have more details.
Every time you use Facebook SDK so it makes any Graph API call, tokens will be refreshed. You can see this in their source code, in AccessTokenManager there is function extendAccessTokenIfNeeded(), and that function is called inside GraphRequest in function executeConnectionAndWait().
You can also manually refresh tokens by calling:
AccessToken.refreshCurrentAccessTokenAsync();
I found one exception to this. Only sso tokens can be refreshed, which means if user logged in to your app via facebook app. If user logged in via browser, token will remain the same.
The previous line to the one you pasted is important:
Native mobile applications using Facebook's SDKs will get long-lived access tokens, good for about 60 days
The section you pulled out refers only to iOS and Android apps using the Facebook SDK - the SDK makes an API call to extend the token, which will only work from the SDK and for tokens produced by the native mobile SDKs-
Other apps (e.g websites, apps on facebook.com) need to use the login flows documented elsewhere in the documentation and require the user to be logged into Facebook in their browser
In my web app, I need to post on users facebook feed while they are offline. I already store long lived access tokens for the users. But these tokens also expire after 60 days.
The FB docs mention that it is necessary to redirect users to the login flow to get a renewed access token.
I was thinking of checking the facebook session validity of user, whenever they login to my app and to give them the option of re-authenticating facebook in case their access token has expired.
However this will involve user interaction if the user is not currently logged in to his facebook account.
Are there any alternative solutions to look at. Also, how do sites like Quora manage posting to user's wall, without needing to re-authenticate facebook after every 60 days.
PS - I am using the latest facebook php sdk.
Simple Answer: It is not possible to extend the Access Token on the server. It would make the whole concept void.
Earlier there was a permission called "offline access", but they changed it to an extended token with maximum 60 days to avoid those things. You should NEVER post anything on the wall of the user without his authorization, for every single post. You are not allowed to autofill/prefill the message parameter anyway (see Facebook terms), it always must be 100% user generated.
About Quora: i don´t know what exactly they are doing, but i assume they refresh the Access Token whenever the user goes to their website.
I'm trying to better understand Facebook Access tokens. I have a canvas web app in a sandbox. I have used the GUI to say the app seeks permissions for various user fields. The user then sees these listed and clicks the blue Go To App button. (Currently only developers and testers).
My questions are around the Access tokens. I've used the Graph API explorer and the Access Token Tool. In the Access Token Tool - there are User and App tokens listed. What are these for?
A user must have a token to use an app - this token is generated when they click to use the app... can this expire? What is the purpose of an app access token? Is this to be used to view which users are subscribed to the app?
Any explanation or step through of the process of accepting and using an app on facebook would be greatly appreciated!
Thanks :)
Access token is similar to a password in a weaker notion.
Whenever a user tries to access to a resource, your app should authenticate the user. In this context, your app requets to access some or all user data, in return you are given an access token that expires in a short period of time. Something like 1 hour, then once the token expires you need to authenticate the user again. There are ways to extend expiration duration upto 2 months.
Facebook docs are pretty clear and concise about tokens, you can read through them, and depending on the language you are using, there are API's you can benefit from.
Overall pretty easy.