Facebook get access_token by username/password - facebook

I implement some facebook related stuff and accessing graph api for that pourposes. But for implement Integration testing I need a simple strategy to get access_token. So I create test user for that. How could I get access_token only with server side involved, without including browser in the chain. Ideally I just need to exchange login/password to the token.
Correct workflow loooks like this:
According the correct answer, there is special tests users provided by facebook.
To to be able to tests system properly you need to do the following flow
Get application access token
Request application's tests user's via "GET /{app_id}/accounts/test-users"
Parse response and extract access_tokens for each user from that response.

You can't exchange the login/password for an Access Token, but you can create test users programmatically. Have a look here:
https://developers.facebook.com/docs/graph-api/reference/v2.0/test-user
https://developers.facebook.com/docs/graph-api/reference/v2.0/app/accounts/test-users
How to get an access token with the right permissions for a test User
https://developers.facebook.com/docs/graph-api/reference/v2.0/user/permissions/

Short answer: You can´t.
Server side you can only get an App Access Token, Page Access Token or extend an existing Access Token.
So it depends on what you need to achieve, if you just want to get public stuff from a Facebook Page, even an App Access Token may be good enough. But you cannot create User Access Tokens server side.
It may be possible with real test users created via the Graph API itself though, see Tobis answer for links about that. But it is definitely not possible with username/password.

Related

How do you generate a access token to retrieve Facebook Ads report stats?

I am trying to retrieve the ads report stats, outlined here:
https://developers.facebook.com/docs/reference/ads-api/adreportstats/
But I am currently stuck with generating an access token. I was going through here: https://developers.facebook.com/docs/reference/ads-api/overview/ ,
And it looks like the only way to generate an access token is to generate it by using live web app.
Is there any other way to generate an access token?
Yes, the only way to get a User access token is to have a user authorise your app via the documented login methods: full documentation here: https://developers.facebook.com/docs/facebook-login/overview/
No.
At least not as far as I can tell. It appears that you need 3 things to generate the token:
App Id, App Secret, Url
https://developers.facebook.com/docs/reference/ads-api/overview/
in the Provide Authorization section.
I'm having a similar issue.
You don't want a client token, you need to generate an access token for the ads reporting.
I've found the Facebook API somewhat confusing because they seem to blur the lines of Access Tokens for accessing user information, and Access Tokens for accessing reporting information.

facebook graph and access token

when I do a get request to
https://graph.facebook.com/[userid]
with the access_token i get all the basic info
but when I do
https://graph.facebook.com/me
with the same token i get an error message: An active access token must be used to query information about the current user
I have tried to under stand what can cause that.
I even tried to token that comes with the signed request
I'm on classic asp, with JSON library, I want the auto to be server side if possible. the FB.api("/me" is working but it is not what i really want to achive
I am pretty sure you don´t have a user access token. Did you login the user? Of course you get the public data of every user with your first link, even without any access token. You can even put it directly in the browser and will get results. But for "/me" you have to authorize the user to your app.
See here: https://developers.facebook.com/docs/howtos/login/server-side-login/
It is the same problem as in the other thread for sure, just a different Programming language.
Remember: If the user did not accept at least the basic permissions in a dialog or redirect, he is not logged in and you will never know anything about him in the app (except for some specifics in tab apps, like language, like-status and stuff).

REST API for website which uses Facebook for authentication

We have a website where the only way to login and authenticate yourself with the site is with Facebook (this was not my choice). The first time you login with Facebook, an account gets automatically created for you.
We now want to create an iPhone application for our site and also a public API for others to use our service.
This question is about how to authenticate with our website from the app/API and is broken into 2 parts:
What is the correct way to handle REST authentication from an API to a website which only uses Facebook OAuth as an authentication method?
I have read and researched a lot about standard methods of authentication for REST API. We can't use such methods as Basic Auth over HTTPS, as there are no credentials for a user as such. Something like this seems to be only for authenticating applications using the API.
Currently, the best way I can think is you hit an /authorize end-point on our API, it redirects to Facebook OAuth, then redirects back to the site and provides a 'token' which the user of the API can use to authenticate subsequent requests.
For an official application that we create, we wouldn't necessarily need to use the public API in the same way. What would be the best way then to talk to our website and authenticate users?
I understand (I think) how to authenticate 3rd-party applications that are using our API, using API (public) keys and secret (private) keys. However, when it comes to authenticating the user who is using the app, I am getting rather confused about how to go about it when the only way we have to authenticate a user is Facebook.
I feel like I'm missing something very obvious, or don't fully understand how public REST APIs should work, so any advice and help would be greatly appreciated.
UPDATE: see below
I've been thinking hard about this question too. It's not entirely clear to me yet but here's the route I am thinking of going. I am creating a REST API an my users only auth with Facebook connect.
On the CLIENT:
Use the Facebook API to login and get an OAUTH2 code.
Exchange this code for an access token.
In every call to my custom API I'll include the Facebook user id and the access token.
On the API (for every method that requires user authentication):
Make a request to the /me Facebook graph using the access token from above.
Verify that the Facebook user id returned matches the user id passed to my API from above.
If the access token has expired additional communication is required.
I have yet to test this. How does it sound?
--- Update: July 27th, 2014 to answer question ---
I only use the above exchange once upon login. Once I determine which user is logging in, I create my own access token, and that token is used from that point going forward. So the new flow looks like this...
On the CLIENT:
Use the Facebook API to login and get an OAUTH2 code.
Exchange this code for an access token.
Request an access token from my API, including the Facebook token as a parameter
On the API
Receive access token request.
Make a request to the /me Facebook graph using the facebook access token
Verify that the Facebook user exists and match to a user in my database
Create my own access token, save it and return it to the client to be used from this point forward
This is my implementation using JWTs (JSON Web Tokens), basically similar to Chris' updated answer. I have used Facebook JS SDK and JWT.
Here's my implementation.
Client: Use Facebook JS SDK to log in and get the access token.
Client: Request JWT from my API by calling /verify-access-token endpoint.
MyAPI: Receives access token, verify it by calling /me endpoint of Facebook API.
MyAPI: If access token is valid, finds the user from database, logs in the user if exist. Create a JWT with required fields as payload, set an expiry, sign with the secret key and send back to the client.
Client: Stores the JWT in local storage.
Client: Sends the token (the JWT from step 5) along with the request for the next API call.
MyAPI: validate the token with the secret key, if token is valid, exchange the token for a new one, send it back to the client along with the API response. (No external API calls for verification of the token here after) [if the token is invalid/expired request client to authenticate again and repeat from 1]
Client Replaces the stored token with the new one and use it for the next API call. Once the token expiry is met, the token expires revoking access to API.
Every token is used once.
Read more answers about security and JWT
How secure is JWT
If you can decode JWT how are they secure?
JSON Web Tokens (JWT) as user identification and authentication tokens
I am trying to answer the same question and have been going through a lot of reading recently...
I won't have "the" answer but things are getting a little clearer for me. Have you read the comments in the article you mentioned? I found them really interesting and helpful.
As a result, and in the light of how things have evolved since the first article has been written, here's what I think I'll do:
HTTPS everywhere — this allows you to forget about HMAC, signing, nonce, ...
Use OAuth2:
When authentication requests come from my own apps/website, use this 'trick' (or a variation of it) described in a reply to the article mentioned before.
In my case, I have two types of users: those with classic login/password credentials and those who have signed up with Facebook Connect.
So I'd provide a regular login form with a "Login with Facebook" button. If the user logs in with his "classic" credentials, I'd just send these to my OAuth2 endpoint with a grant_type=password.
If he chooses to log in via Facebook, I think that would be a two-steps process:
First, use Facebook iOS SDK to open an FBSession
When that's done and the app is given back control, there should be a way to get a Facebook ID for that user. I'd send this ID alone to my OAuth2 endpoint with an extension grant understood by my server as "using an FB User ID".
Please note that I am still heavily researching on all this stuff, so that might not be a perfect answer... maybe not even a correct one! But I think that would make for a good starting point.
The idea of using an "extension grant" for the Facebook authentication might involve having to register it to do things properly? I'm not quite sure.
Anyway, I hope I was able to help you even a bit, and that at least it can start a discussion to find the best solution to this problem :)
Update
The Facebook login is not a solution as pointed in the comments: anybody could send an arbitrary user ID and log in as this user on the API.
What about doing it like this:
Show a login form with a "Facebook login" button
If this login method is chosen, act kinda like the Facebook SDK: open a web page from your authentication server, which will initiate the Facebook login.
Once the user has logged in, Facebook will use your redirect URL to confirm; make that URL point to another endpoint of your authentication server (possibly with an extra parameter indicating the call came from an app?)
When the authentication endpoint is hit, the authentication can securely identify the user, retain its FB User ID/FB Session and return an access token to your app using a custom URL scheme, just like the Facebook SDK would do
Looks better?

Is using the Facebook access token a secure way to validate a user?

On my app the user can sign to Facebook and the app then has the user's access token (say it's 'abc'), I want to use this token to create a user on my own server.
Is it safe to send this access token to my server (using SSL), then get the user's username and ID using https://graph.facebook.com/me?access_token=abc on my server and check that the application the token belongs to is mine with https://graph.facebook.com/app?access_token=abc. If it is my application I then store the user in my user's database and/or log them in.
Can this system be fooled? Can you think of a way someone could log in as someone else?
You should check out all of the Authentication documentation and the Oauth spec to see the different auth flows available
Broadly speaking, you can create a user on your server based on the access token, and be reasonably certain that when you get an access token from Facebook for the same user ID that it's the same person.
If you require very high security for the app you can take steps to ensure the user's access token wasn't produced via malware or the Facebook user being tricked, there's an example showing protection against CSRF in the Server Side Authentication documentation, and there's also a reauthentication flow you can use
I assume that you are using facebook sdk for this, if so the facebook sdk takes care of the security for you and you don't have to worry about a thing.Supposing that you are accessing the api without the sdk then there are two things that must be noted:
1) Auth token expires frequently(facebook has taken great pains to ensure that the user is protected)
2)Making a request with just auth token is not enough there are some other parameters that are needed that can't be faked especially if you are doing this server side since an extra layer is added that fb calls server flow authentication
3)On top of that there are a lot of permissions that are in place that the user has to give in order for an application to access some data.The link below provides a nice article on authentication you can take a look
https://developers.facebook.com/docs/authentication/
So long story short it is safe.

developers.facebook.com issued access token VS OAuth generated

Interesting problem I'm having right now.
Signing in an App gives a access token looking something like this:
AAACwFsGcSr4BAOGUTwfuZAWuUcwZC0rJ7noZCKMqhBI7ivDCsIGqduGIZCus5PRaS6KuREqxLmhfvZAZAkz5WCpFfANtUpYHgZD
This access token can't access users PUBLIC information, while one issued by Facebook on developers.facebook.com - CAN.
You can easily test this by logging to your facebook and going to this link: http://developers.facebook.com/docs/reference/api/
You'll see that Facebook automatically generates access token on DEMO urls like this one:
https://graph.facebook.com/me/music
?access_token=2227470867|2.AQCvlA_ZaJ2MfRR0.3600.1318266000.0-100001572415177|2FeweU6ZvOQS9OCF5ZBV58_PtPg
If you would change /ME/ to any user which has his MUSIC posted as public, you WILL be able to access that data with Graph API.
Now try to get an access token to your APP and call the same Graph API method with generated access token, the returned data is empty JSON object.
Whats’ the difference between these access tokens? How to obtain access token, that I could get public information using Graph API?
I was thinking that logging in your APP is the highest possible access token and the only higher token is token with specified permissions...
Any guidelines would be great :)
http://developers.facebook.com/docs/reference/api/permissions/
I believe the difference is that you can specify additional permissions in a scope parameter,
so if you wanted to read a user's feed you would have to specify read_stream. I was trying to accomplish this with an access token from a server-side authentication flow in ruby, but the access token only allowed to me to navigate accross a certain portion of graph.facebook.com/user_id/feed? requests. If you get any insights or comes across a solution shoot it my way too, if you can.