Facebook User Access Token Security - android

Is it secure to user the User Access Token to make Graph Api calls directly from the client (in my case Android app)? And as the SDK refreshes the access token for client, token hijacking won't be a major issue.
I am fetching the User access token using the method
AccessToken.getCurrentAccessToken()

It is secure to a a extent to use it, but as far as i am concerned it is better to use JWT for Authentication purpose, in JWT a unique id is generated for your token and we can use that id within the app for all the purposes.

Related

Handling Oath 2.0 Authorization from Backend Job

I am trying to find a solution to the following:
Requirments
There is exists an app that allows users to add integration providers
These integration providers use oath 2.0 authorization to secure their data
The app needs the ability to have a backend job fetch data on-behalf of the user once per day
The data fetched is ingested and merged into a report that is compiled on the app for the user
Problem
User Delegated Access Token from Backend Job - I'm having trouble finding the solution that allows me to have a valid access token that is on behalf of the user without having to generate the access token from the app side
What I have tried
Refresh Token - I have tried the approach of using the refresh token to constantly get a new access token but this solution is fragile in the sense that there might be a situation that a new token is not generated in time or for some reason the user still needs to reauthenticate the connection to the provider
Automated Browser Flows - I have tried automating the user's authentication flow from the backend using saved credentials given in the app. This approach is just sketchy, costly, and would require a lot of work on the user agreement side ensuring that is being done on the backend has been consented by the user which essentially reinvents the wheel on user consent which the identity providers should have already been handling
We can use JWT for this. By doing it with JWT we'll create a token and save to the database and on every request it will decrypt the token and get the required data from the token.
Link- https://jwt.io/

How can I securely store user credentials for my app

I have an Android app that allows users to interact with a third-party service via their API. This API makes use of Basic Authentication, so I need the user's username and password for every API call. Ideally I don't want to store the user's credentials locally as this is very insecure. I don't know much about authentication but this is what I think my ideal solution would be:
The user provides their credentials to this service once for verification
Once verified, I send the user's credentials to a backend service to store them, which gives me an auth token. I store this token locally (is encryption important here?)
Whenever I want to make future calls to this service, I use this auth token to talk to the backend service, which provides me with the user's username/password for Basic Authentication to make API calls
Is this a good solution? If so, are there backend services in place that I can use to facilitate this process? I've looked at Firebase Authentication but I don't know if it fills my needs as I'm trying to store credentials for a third-party service, not specifically for my app. I've heard of Auth0 which may be what I'm looking for but appears to be overkill for a small app like mine.
You can easily use Firebase Auth and get all the functionality you need while keeping your users secure. It provides the features you need:
Firebase supports password authentication and properly stores hashed/salted password credentials according the industry standards. This would be one API to createUserWithEmailAndPassword or signInWithEmailAndPassword.
Firebase provides a mechanism to verify email addresses. It is also one API: user.sendEmailVerification()
On sign in, Firebase Auth returns an ID token (user.getIdToken()) which you can use to identify your users in all authenticated requests. They also provide an Admin SDK to parse and verify that token (auth.verifyIdToken(idToken)). A refresh token is also provided to continuously refresh ID tokens on expiration. This means the sessions are indefinite and the user should not need to sign in again on the device.
The ID token provides additional user data like email_verified which you can use to ensure the user is verified. The ID token is a JWT which can't be compromised without the Firebase Auth backend private key.

Implementing JWT authentication in Android using Account Manager

I’m implementing a Android app and that must contain a user login. To do this I create my own authenticator with the purpose of login only once. Then AccountManager can request access tokens, so the application is not handling passwords directly. The AccountManager stores the user account and the token.
I’m using JWT (Json Web Token) to authenticate the user in my REST API.
I wonder whether this flow is correct or there is a better approach to do this in Android.
Here is the flow I am currently using:
The user enter user and passwords in the login screen at first time.
I make a request to server to retrieve a valid token (JWT) that is stored in the Account Manager.
Subsequent requests use the received access token until it is expires (1 hour) to retrieve content from the API.
After the token is expired, it can be refreshed up to two weeks after issue time. From this moment, user credentials are needed to retrieve a new token.
Is this process the correct way to work with the token, and refreshing it? Is the process safe? Are there other options?
Considering this flow is not using a “refresh token” to generate a new one but the access token, what would be the best usage of the Android Account Manager? What other tools should I use? Is it recommended an Oauth2 implementation along JWT in order to implement a “refresh token”?
Cheers!
I can tell, you are on the right road of using JSON Web Tokens and reproducing it.
but the safety you mentioned is all about encrypting the token you retrieved and then saving it in Account Manager (also the same with user credentials) with some encryption method of your choice like AES or RSA and then decrypt if when you wish to use. Also using a server-generated secret key with a secret algorithm would kill the shot for any hacker.
As you understand everyone with a root access can get hands on the saved credentials database and use it.
Using these tricks will lower the need of using Oauth 2.0 which involves a refresh token.
hope it helps

facebook deeplink with app link host

According to facebook development site.
https://developers.facebook.com/docs/graph-api/reference/v2.0/app/app_link_hosts
Under Publishing section
I tried with Android SDK but got this error
{"error":{"message":"(#200) Permissions error","type":"OAuthException","code":200}}
I tried with Curl option but got the same error
{"error":{"message":"(#200) Permissions error","type":"OAuthException","code":200}}
Ok so I double check my permission﹕ [public_profile, rsvp_event, publish_actions]
I have the correct permission It is so simple. Unless I miss something.
EDIT
Also check that the access_token is passed in.
If anyone have a solution please share.
I faced the similar problem like you did. It turns out that there are various types of access tokens. https://developers.facebook.com/docs/facebook-login/access-tokens,
User Access Token – The user token is the most commonly used type of token. This kind of access token is needed any time the app calls an API to read, modify or write a specific person's Facebook data on their behalf. User access tokens are generally obtained via a login dialog and require a person to permit your app to obtain one.
App Access Token – This kind of access token is needed to modify and read the app settings. It can also be used to publish Open Graph actions. It is generated using a pre-agreed secret between the app and Facebook and is then used during calls that change app-wide settings. You obtain an app access token via a server-to-server call.
Page Access Token – These access tokens are similar to user access tokens, except that they provide permission to APIs that read, write or modify the data belonging to a Facebook Page. To obtain a page access token you need to start by obtaining a user access token and asking for the manage_pages permission. Once you have the user access token you then get the page access token via the Graph API.
Client Token - The client token is an identifier that you can embed into native mobile binaries or desktop apps to identify your app. The client token isn't meant to be a secret identifier because it's embedded in applications. The client token is used to access app-level APIs, but only a very limited subset. The client token is found in your app's dashboard. Since the client token is used rarely, we won't talk about it in this document. Instead it's covered in any API documentation that uses the client token.
So the access token in this case is referring to App Access Token. You can obtain one using the API Explorer:
Note that you also need to be the admin of the Facebook app to be able to get the an App Access Token, if not the button will be greyed out like what is shown in the screenshot above.

How can I get a signed access token from facebook using OAuth 2.0?

I want to identify the an android native app user on my web service. I don't want to include a secret in my java, as that would be trivial to find. Using the javascript sdk on the website, the token is signed and I can verify it with the shared secret on the server, but the android sdk just gets a token.
I had hoped that I could pass the token and the signature to my web service and then I could verify that the actions the user were taking were authorized. Is there a way to get a signature of an access token (and the shared secret) already granted from facebook?
I ended up just passing the auth token to my web service, having the server verify it's valid (by getting graph.facebook.com/me) and then creating my own signed token that I sent back. I authorize based on that token from then on... Kinda lame.

Categories

Resources