After extending an access token, does that make it valid for another 60 days? - facebook

If I requested and acquired an access token on, say, the 1st of March, and extended it on 30 days later, will it be valid for another 60 days, or does it require reauthorization from the end user?
We are implementing an autopost functionality, which is triggered by an event inside our own application. Therefore, the end user will not be able to present their cookie to Facebook in order to validate their identity. We need to make sure that we always have a valid access token.
The official Facebook documentation is quite vague on this particular subject.

How are you obtaining the access tokens? Server side flow or client side?
What exactly do you mean by "extending" the tokens? Are you referring to the "new end point" provided by facebook because of the offline_access deprecation?
You are right, facebook are pretty vague about it saying:
If you would like to renew a still valid access_token, you will have
to get a new client-side access token first and then call the same
endpoint below. The returned access_token with the newly extended
expiration time may or may not be the same as the previously granted
extended access_token.
That means that you can not count on the extended token to actually be extended.
More than that though, is that you can't just extend the token with out any user interaction. If the user haven't used your app in the last 60 days you can not extend the token for him.

You can use the App Access Token if you want to publish on users behalf. The App Access Token does not expire unless you de-authorize it yourself. When using your App Access Token you have to specifically indicate the user id you are publishing for - /12345678/photos. You can't use /me/photos. You can read more about this here.

Related

Facebook Tokens - I created a never-expiring token, but how?

I have been trying to create a never-expiring Facebook Token (ideally programatically) and have not been able to do so, then, without really trying, on a different Facebook Application, I managed to create a token which, according to
https://developers.facebook.com/tools/debug/accesstoken?version=v2.5&q={TOKEN}
will never expire and I can't replicate it on any other Facebook Apps or for any other Facebook Tokens.
I can programatically (PHP) take the short lived token (1/2 hours) and extend it to 60 days, but I wanted to ideally get a never-expire token.
I guess I'm not asking how I managed to do it, but I can't find any explanation or documentation nor reason as to why I was able to achieve this for one token, but not any others.
Is it something in the App itself while it was created? Is there actually a way to get a never-expiring token, even though I've followed many of the guides online yet can only get a 1/2 hour token converted to 60 days?
Is there actually a way to get a never-expiring token
No, not really. Even what you think is a never-expiring token can expire - f.e. if the user who created it changes their account password.
I guess I'm not asking how I managed to do it, but I can't find any explanation or documentation nor reason as to why I was able to achieve this for one token, but not any others.
It is not documented, because Facebook wants you to use the 60 day tokens, when you app is acting on behalf of a personal user profile. They removed offline_access permission ages ago, specifically so that apps the user has long forgotten about can’t act on their behalf or still access their data any more.
So if you are writing an app that acts on behalf of users, you should really rather make do with the 60 day token - that should be enough for most cases.
Now what you are seeing with your token here, is a side effect of how Facebook has implemented extended page access tokens. Those do not have a default expiry - but they need to be invalidated when the user is removed as a page admin. Therefor, they are internally tied to the user token that was used to request the page token. User token gets invalidated - page access token becomes invalid together with it. And that in turn requires that the user token does not automatically expire after 60 days.
So, when you extend a user token that includes manage_pages permission, you will get an extended token with “unlimited” validity. But, again, that is a side effect of current implementation only, and can change in the future.

Facebook OAuthException: This authorization code has been used

This question is related to this question already asked.
Does this Facebook change mean that we have to store the user token returned the first time and reuse that for all subsequent Facebook requests? What happens if we do not store this user token - can we request it again? If yes, how do we do that?
Also, when does the user token expire, if it ever expires?
This documentation shows how to get data about an access_token. You make a call to:
https://graph.facebook.com/debug_token?input_token=INPUT_TOKEN&access_token=ACCESS_TOKEN
Best practice is to store an access token and its expiration. This documentation shows how to extend a session.
Note this quote found in the 2nd link:
When a user completes a client-side auth flow and you retrieve their
User Access Token, by default you'll receive a short-lived token that
is only valid for 1-2 hours. There is no Javascript SDK function to help extend this, however, you can exchange this token for a longer lived one (valid to 60 days)

Can I retrieve a Facebook access token if I don't store it in my database?

I have been asked to look into whether or not I can retrieve a Facebook access token from Facebook if the user had granted permission in an earlier session. The problem is that our business logic tier is maintained by a different group and is on a different release schedule from the web development group. If I were to gain an offline access token, I might not be able to store it for up to two months. For any users acquired in the meantime, is there a way that I can retrieve the token from facebook without further intervention from the user?
I would think that this might be a security hole, but one of our senior developers thinks that it is likely that facebook offers such a feature.
Thanks,
Rob
In short No.
But with the offline access request being complete.
You can request a new token without any user clicking.
You just get a new offline access token and use that. The same way as if you didn't request offline access, and the access token had expired, it doesn't explicitly say but it does work:
In addition to the access token (the access_token parameter), the response contains the number of seconds until the token expires (the expires parameter). Once the token expires, you will need to re-run the steps above to generate a new code and access_token, although if the user has already authorized your app, they will not be prompted to do so again. If your app needs an access token with an infinite expiry time (perhaps to take actions on the user's behalf after they are not using your app), you can request the offline_access permission.
http://developers.facebook.com/docs/authentication/
That way you don't have to store them at all.
Unless you actually want to perform actions when the user is not using your Application.
You'll get the access_token every time the user logs back in, offline_access or not !
You can get it in JS with FB.getAccessToken();
There is no way to retrieve (offline) access token, when the user is not actually logged in.
If you want to store the access token for a long period of time, you will be required to ask for the offline_access permission, otherwise the access token will only last a short period of time. Either way, it is best to store it in a cookie or locally as it will certainly improve your app's latency. But make sure to check its validity as often as possible.
I think the access_token means, you have the permission to do things on behalf of the user. If you must do something without user FB login, you need the offline access_token. But be careful, the offline access_token will be ignored, when the user change his/her FB password, or delete the application.
So I hope there isn't any way to get another access_token without the user permission. I think the easiest way to check the access_token to make a /me?access_token= GET request, and check the answer. If the answer is an error, the access_token not working, you have to renew it.
To get access_token from somebody in the middle of the flow is a little pain. But you can also put variables to the redirect link.
Example:
https://graph.facebook.com/oauth/authorize?client_id=API_KEY&scope=email$redirect_uri=YOUR_REGISTERED_APP_URL%3F$param
$param could be a flow info like: flow=12342323
So when your user come back the $_GET['flow'] will be 12342323.

How long do 'offline_access' OAuth tokens last for?

If a user gives my app the offline_access permission, approximately how long will the OAuth token last for? The documentation simply says:
"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."
How long specifically would this token last for? Would it be active 24 hours later?
If I recall correctly, the access token returned when requesting the offline_access permission will remain valid until the user revokes the offline_access extended permission from the application, or the user specifically removes the application. Effectively making it a permanent token.
However, this should always be taken with a grain of salt. Facebook allows themselves the freedom to be able to change their policies at anytime and the 'long-lived' wording of the description allows them to invalidate the token at any time. It is recommended that your application handles the scenario of the token becoming invalid as it will cover the user removing application access and the token being invalided for some other reason.
Some helpful information from Facebook here on handling expired access tokens:
https://developers.facebook.com/blog/post/500/
Note that an access token can also expire if the user changes their password or deletes their Facebook account.
Your client (web, iOS, etc) should make a habit of checking for a valid access token & reprompting the user to authorize if the token has expired.

Do Facebook Oauth 2.0 Access Tokens Expire?

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...