How to set up a Facebook Chat API connection when authorizing as a Desktop App - facebook

The problem I am facing is that after I authorize my app for current user using
http://developers.facebook.com/docs/authentication/ (client-side flow)
I can't setup a XMPP connection as I need to know session key to access it. When using server-based flow, the session properties are being sent as a part of access token. And I didn't find a way to get the session key for my oAuth based authentication client-side flow.
Please suggest how can I get it.
I'm doing all requests from javascript (Google Chrome extension).

Facebook is actually deprecating the session key. They have just recently (a couple days after you posted the question i believe) updated their authentication method to no longer require the session key. If for whatever reason you still need it you can get it by looking up the auth.promote_session method in the REST API, but that is deprecated and will be removed come October.
If you check https://developers.facebook.com/docs/chat/ you should find that the access token will get you what you need now.

Related

Using Facebook or Google login API with Classic ASP

I'm running a Classic ASP website, that has its own user authentication and login mechanism. For example, In order to remember a logged-in user, ASP creates an encrypted cookie and a 20-minute session for each connected user. If the 20 minute session is elapsed, the server revives the session from the cookie saved previously, and saves some data regarding the user to the database.
I want to to be able to allow users to connect with their Facebook or Google identity, but the mechanism used by Facebook or Google is based mainly on Javascript and on client-side code.
How Facebook or Google login can be used while maintaining server side code in ASP? (So that the ASP server can still manage the session and save data regarding it, for example whenever a session is revived)
For me somehow it seems that it may become less secure to use client-side authentication as the code may be altered easily. Isn't this the case?
If I use client-side javascript and log in with Facebook, how would I update the user data retrieved from facebook back into my database, for example the user's first and last name?
For me it sounds that it should be a "server-to-server" communication (between my ASP server and Facebook's or Google's servers) and what they propose is a "client-to-server" communication ... Any ideas how this can be done?
Any help or explanation would be very much appreciated! Thanks.
I'll try to address your Facebook-related questions one by one. However, I will not give you an implementation or any ASP-specific feedback, but only a rough approach. Additionally, I recommend that you study Facebook's documentation on Facebook Login extensively to further your understanding of the matter.
1. Facebook documents the server-side OAuth 2.0 flow in their Manually Build a Login Flow guide. Basically you redirect the user to a specific FB URL that (in the parameters) tells FB to render the "Login with Facebook" dialog, and which permission scopes to ask for. Once the user approves the Facebook Login for your webapp, they will be redirected back to your web app, e.g. with an OAuth token in the query string, that your webserver can then exchange for a user access token.
Once you obtained a user access token, you could e.g. store it in your web app user's session.
2. I don't know what you mean. Client side apps are fairly secure. Perhaps you can convince yourself about how secure JS apps are when reading about things like CORS.
3. If you only use JavaScript (e.g. Facebook's JS SDK) and you want to store e.g. app-scoped user IDs on your server, you need to expose an endpoint on your server that your JS application can submit that kind of information to.
4. You state
what they propose is a "client-to-server" communication
Who are "they", and where are the proposing this? The resources I linked to in 1. should explain how you can use Facebook login in a pure server-to-server way.

Facebook, Node & Mobile app - pulling together

I'm trying to build a Facebook-authenticated native mobile app (Windows Phone) that connects to a web service I am creating in Node.
I'd like for a user to:
Log in to Facebook on the mobile app via a native UI or web window
If logged in successfully, create or access server-side user account data tied to that identity
Use the authenticated session to make subsequent authenticated requestsvto that user's data via the native mobile app
My question is: What's the best approach here?
Should I...
Log in the client to facebook locally in the mobile app and pass the Access Token to the node service, and then somehow map the user to my service data based on their facebook account id? That seems grossly insecure if I just pass that token in the URL.
Log the user in via a mobile browser window inside my app, and then redirect back to my Node service in the same window? How do I then make subsequent authenticated requests natively in my app?
Do something else entirely?
Sorry this is so open ended but this is the first time I have tied these things together and although there's a lot of info on each part I've yet to find something that describes the overall pattern / best practice for this design.
Your question is quite opinion based...but still I will try to help.
First of all, you can pass access token in url, its not insecure if you use https. Even if logged into facebook from your mobile app, than also its going to pass a access token in url only. If you mean having the token in http://something.com/access_token, than its not how its should be done.
If you look into the Oauth 2.0 draft you will understand that its done through setting a header Authorization with the value being the token and token_type. Take a good look at the draft.
As your solution I think its fine if you just use the first method mentioned in the question by sending the access token in header as I mentioned in your app and in turn authenticating that token from facebook on each request.
If you think this is just too long a flow for authenticating every request from facebook, than you can get access token by sending request from your mobile app to server and let the server handle the access token and store it in database which you can authenticate each request.
In any case take a look at Passport module, it has facebook and other auth built-in and should be sufficient for your needs.

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.

Interaction with Facebook API without full OAuth, is it possible?

I need to post message on a certain FB page as a owner by cron, using php and ZF 1.1.X. For this small issue, I don't want to create a full OAuth stack. Is it possible to communicate with FB API (it's desirable, PHP SDK for FB) without it, such as twitter with his precreated access tokens (Access token, Access token secret)?
As long as you need an active user access_token to retrieve desired data this is not possible to skip OAuth flow.
Without authenticating user you only have application access_token (in old format APP_ID|APP_SECRET, but it's still works) and only limited access to most of Graph API endpoints and Application settings.
Actually there is nothing hard in implementing the user authentication with OAuth flow and it is completely transparent with usage of PHP-SDK.
Just look at the sample code in documentation for server-side authentication
Yes, you need to build an app and then authorize the page via the app while requesting the manage_page permission.
You should make yourself familiar with the Server Side Auth process as well.