Facebook OAuthException: This authorization code has been used - facebook

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)

Related

Increase access token validity

Is it possible to generate an access token to read the feed of a facebook account, where the access token never expires.
From what I understand 60 days is the maximum if the initial login access token is exchanged.
Is it possible to go longer than 60 days?
Now that offline_access is no longer provided, the answer is NO.
There used be a permission called offline_access that let access token works longer for period of time, but it is removed now. Short-term access token and long-term access token are introduced, instead.
When you redirect your potential user to Login Dialog and the user complete his login and app authorization process, user is redirected back to your web page. That's where you get code parameter and you will exchange it for short-term access token, which stays valid for about 2 hours. That should be enough for login purpose.
If you wish to store the token for later use you should acquire long-term access token. I believe this is the one you mentioned. This token lives up to about 60 days as you already figured out and it is the longest.

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

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.

Does a Facebook application's access token expire?

This is the access token associated with my Facebook application -- the thing that comes back from https://graph.facebook.com/oauth/access_token?grant_type=client_credentials&client_id=APP_ID&client_secret=APP_SECRET. Can I get this once from FB and save it away somewhere for future use, or do I need to refresh it on a regular basis?
Access Token Tool - Facebook Developers
App tokens do not expire and should be kept secret as they are related to your app secret.
I don't know for sure, but since the documentation does not state that you get back an expiration time for the access token, I guess that it's an educated guess that it does not expire.
But why does it matter? the application authentication process is much simpler than the one with users, so just save the token somewhere (db, memory) and then try an api call, if it fails just issue one call to obtain a new token, save that, and continue as usual.
If you want a token to manage a page, never-expiring token can be obtained by
Get user token
Exchange user token to long-living token (Valid for 30days)
Obtain a page token with this user token (This page token is not going to expire)
When you check the token you've got, check it on Debugger. You will now see 'Expires Never'.
Documentation is on Facebook Developers ,Scenario 5: Page Access Tokens
My app access token does not seem to have changed for just under a month. I do not know if it changes. For fun I just changed my app secret...
My app access token then immediately changed and when I try to use the old one I get a
HTTP 400 error with a message body...
{"error":{"message":"Invalid OAuth access token signature.","type":"OAuthException","code":190}}
My advice is save the access token and use it. Unless you get the message above in which case obtain a new one and use that. One thing that I have not checked yet is if you get the same result if the user access token (that you may be querying) has expired instead.
For each and every user token (which is what you're getting from your link), there is an expiration date. Take one of those tokens to https://developers.facebook.com/tools/debug and debug it. You will see that generally they expire within 60 minutes or so.
To extend that user token, call the exchange command (https://developers.facebook.com/docs/offline-access-deprecation/) to get it to become a 60 day token. That user token has to be still valid (not expired) to do this.

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.

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...