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

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.

Related

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.

how can get data from facebook api and write those data in my own database using web services?

For this task I have already created my own facebook application to get the API key and secret key. Can anyone explain the next steps that should be done to
1) Read from facebook API
2) Write my own database
by using web services
Thanks in advance!
A high level answer:
I'm assuming you want to use the authorization code OAuth flow (this means you want Facebook users to give you access to their profiles so you can grab data from there). If so, you need to bring up a web server and an application that will run your users through the Facebook OAuth flow. In case you just want to access Facebook with your own credentials you don't have to have a web server, simply use the client credentials OAuth flow.
So, Once you have a valid access token, you simply make calls to Facebook API using this token. using Facebook Graph API is simply a matter of calling URLs and getting the data as JSON.
You can test-drive the API here.
BTW, according to Facebook's platform policy, you're only allowed to store Facebook data for caching purposes.
Let me know if this helps.

Is it possible to send a request to the Facebook Graph API from client side without exposing our access token to the public?

My question is related to, but not exactly, this question.
I am currently working on a business directory Web site (similar to Yelp), in which businesses have their own pages. Let's call this app DIRECTORY_APP.
Businesses might want to have their latest Facebook status update shown on their pages hosted on our directory. Let's pretend we have a business named BIZ_1. The assumption is that those pages are public pages.
Apparently the Facebook Graph API can be used for this purpose. So I can send a request to Facebook to retrieve the latest status updates for BIZ_1:
https://graph.facebook.com/BIZ_1_PROFILE_ID/posts?
access_token=DIRECTORY_APP_ACCESS_TOKEN
&callback=callbackName
However, if I use this from the client side, our Web site's access token will be exposed to the public, so this is not a reasonable solution.
Now in the aforementioned question, Anatoly mentions that we can retrieve the access token by sending this request first:
https://graph.facebook.com/oauth/access_token?
client_id=YOUR_APP_ID&client_secret=YOUR_APP_SECRET
&grant_type=client_credentials
However if someone inspects the Network log, this will also expose our Web site's access token (is this correct or is this a different type of access token?). This solution also exposes our web site's app secret (is this safe?).
So to summarize, what's a safe way in which I can retrieve the latest status update of a Web page from client-side without asking the browsing user to first log in to Facebook?
I can retrieve the latest status update of a Web page from client-side without asking the browsing user to first log in to Facebook
You cant do that without login.
And I guess access token is not exposed.
Maybe the smart trick here is to use a social plugin. The Like Box will do what you want, without any issues. But, it's not greatly customizable. Even so, it's possible to get it looking nice on a page!
It also skips any login issues you mentioned.
I found the answer after some Googling. In short, the answer is no.
And here's an excerpt from Facebook:
Security Best Practices
App Secret and App Access Token
The App Secret is used in some of the Login flows to generate access tokens and the Secret itself is intended to secure usage of your App to only those that are trusted. The secret can be used to easily create an App Access Token which can make API requests on behalf of any user of the app, which makes it extremely important that an App Secret is not compromised.
Therefore the App Secret or an App Access token should never be included in any code that could be accessed by anyone other than a developer of the app. This applies to all methods of code that are not secured like client-side code (such as HTML or Javascript) or native apps (such as iOS, Android or Windows desktop apps) that could be decompiled.
We recommend that App Access Tokens should only be used directly from your app's servers in order to provide the best security. For native apps, we suggest that the app communicates with your own server and the server then makes the API requests to Facebook using the App Access Token. For this reason, if your 'App Type' under Advanced Settings in the App Dashboard is set to Native/Desktop we assume that your native app contains the App Secret or an App Access Token in the binary, and we do not allow calls signed with an App Access Token to proceed. The API will behave as though no access token was provided.
If your App Secret is compromised, you should reset it immediately in the Basic Settings of your App Dashboard.

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.

Facebook API: Access Without Reauthentication

We're hoping to create mobile phone applications for (among other features) posting video to a user's FaceBook page. However, using their API, it looks like we would need to open a web viewer and have the user enter their login credentials every time the application is used. We would prefer to store these credentials so the user only has to login once.
We could of course save the http login post and resend it as needed, but this breaks if FaceBook changes their API and I worry about their terms of service and using an unofficial hack such as this.
Maybe someone knows of another application that uses Facebook this way?
You should have been returned an oAuth token to use.
The new Facebook API has a service you can call with the old tokens and it returns you a new oAuth token.
You just have to add offline_access to your permissions. You do this by adding &scope=offline_permissions at the end of your authorization url. Then your oAuth token won't expire.