Login with password and facebook - oauth-2.0

I am in the process of designing an app that is supposed to let you login using either a username/password combination or facebook login. We have a custom OAuth server that uses user credentials to authenticate users. Now, the question is how to add facebook into this.
As I see it now, when the user wants to login with facebook, the client does all the work and gets the access token in the end. But how do we let our server know that this access token is a good one (and corresponds to a user in the database)? To me it seems like our OAuth server should be able to handle this as well, and I'm just missing the how.

OAuth supports different scenarios (flows). Client-does-all-the-work is so called "implicit" flow.
In your case it would be better to use authorization-code flow and extend your OAuth server. You put a "Facebook" button on your login page and instruct Facebook to redirect to a new special page on your OAuth server. Delivered authorization code then can be exchanged to the access token inside of your OAuth server and the server may issue its own session and tokens based on this.

Related

How should the server for a single-page application handle expired oAuth tokens?

As background, I'm using the Google OAuth2 NodeJS client, but I think my question is more abstract / technology independent.
My website is single-page application that communicates via AJAX to the server.
When a user first visits my website, I perform an OAuth2 flow which redirects them to Google to log in, and then redirects back to my site with an access token. I store this access token in a cookie, and use it to handle various calls made to the server via AJAX.
My challenge is that I'm unsure what to do when that access_token expires. Should I be storing the refresh_token in a cookie as well, and using that, or are there security issues in doing so?
Should I be redirecting the browser to perform the login flow again? That seems fairly ugly for a single-page application.
You can do the OAuth2 flow via js in the background(like the login flow with the popup window), and if the access hasn't been revoked for you app id, then the user shouldn't see anything about it. Although you can set a hint on the user email to authenticate, this may not work.
The other way that you mentioned, is the refresh token, that you can use to ask for a new access token, without user interaction. Maybe that would be the better idea, but remember, that you will only get a refresh token if you set the access type to offline.

OAuth 2.0 without a login on iOS?

For my current work project we're trying to use OAuth to secure a mobile API, but the app doesn't have user accounts, so authentication would take place invisibly from the user, where the app will send up some secrets to the server and receive the token to be used for subsequent web service calls. The problem is, all the libraries and tutorials I can find implementing OAuth follow this pattern:
Present a web view allowing a user to login
Receive a callback to a custom URL scheme, and parse the necessary information to authenticate future web service calls
How do I achieve this without the webview step? I should be able to make an HTTP request directly with the correct credentials which will return the necessary authentication details.
The app will use OAuth 2.0
It is not clear what do you mean by
the app doesn't have user accounts
If you want to call some API on behalf of user you should ask him for a password. Doing it in webview or not depends on provider implementation. For example, twitter doesn't force you to do that.
In other case, if you want to call service on behalf of client, take a look at this answer: https://stackoverflow.com/a/7477112/2283405
If the app doesn't require "personalised" or "user-specific" data to be manipulated, then you can probably try using "client-credentials" grant type to obtain access tokens using the application credentials granted upon the application registration process by the Authorisation Server (for e.g.: OAuth server) that's there in your environment. The idea is that, your app is what basically authenticates with the Authentication Server for you using the aforesaid credentials (i.e. Client Consumer Key and Client Secret Key).
NO, you have to do login compalsary. if you try without. it won't be possible.

Thinktecture single sign out

I am working on a AngularJS web app and I am trying to implement single sign on. I had a nice implementation using Identity server and authorization server with implicit flow and oAuth tokens, however I need a mechanism to sign the user out of all apps they are signed into.
I am currently redirecting the user to authorization server, this then redirects the user to identity server. The user logs on and it shown a consent screen, a Json web token is then sent to the app via the query string and is put into local storage. This token is attached to the Authorization header which the web api (that is on a different domain) receives and either allows or denies the request.
The problem is oAuth has no way of singing a user out of all apps. I have now looked at WS-Federation using Json web tokens but this approach still appears to use cookies which I would like to avoid as the api and client app are on different domains.
Does Thinktecture Identity Server have any way to do this and if so are there any examples I could take a look at.
Thanks
As you already said - OAuth2 is not an authentication protocol and hence does not have the concept of (single) signout.

Doorkeeper without web views

I'm using Rails to write an API for mobile application and OAuth seems like a standard way to handle user authorization.
If I understand Doorkeeper docs correctly it requires user to be signed in with the website before it grants access for the mobile app.
The issue in may case is that there really isn't any website (it may be in the future but for now it's just api). I would like the user creation/signing in etc be handled in the ios application.
This makes me wonder if OAuth is the correct solution here?
The OAuth "Resource Owner Password Credentials Grant," according to rfc6749 Section 4.3, will grant an authorization token and optionally a refresh token given user name and password. Thus the mobile app doesn't have to store user name and password to gain authorized access. It becomes like a long running session using token and refresh token. OAuthClientSetup an iOS example that runs against a doorkeeper api.
So there is the OAuth method for gaining authorization without having web site login authentication and access grant.
What is left is how to register new users from your mobile app. Agree that does not look to be covered by OAuth. OmniAuth will let you register a user authorized by a third party site. You allow the user to be the user they are on Twitter or FaceBook, StackOverflow or GitHub or wherever else. Maybe that would help.

can an OAuth consumer app expose an API to an iOS app?

I'm creating an app for iOS that consumes an API I've created, which requires authentication and authorization of users. I'm thinking of using OAuth to let the mobile users do this with Facebook. This is an internal API that isn't meant to be exposed to third parties.
Anyway, I'm a little confused about the abilities and limitations of OAuth consumers versus OAuth providers. Basically, I want to implement "Login with Facebook" functionality from the iOS app. It seems to me that this implies that my API should be an OAuth consumer, but the problem with this is that the login flow for a web app assumes a browser -- an NSURLConnection instance isn't going to know what to do with an HTML login page, and even if the redirect to the login page was made to work by prefixing the redirect URI with the fb:// schema, surely the login form is going to pass the authorization token back to the iOS app and not my API?
So my question is: is there a way to implement my API as an OAuth consumer? If not, and I should implement it as an OAuth provider, what does logging in with credentials from another provider like Facebook even mean?
I think things are a bit mixed up:
OAuth is to Authenticate your app against facebook. A user grants
access to his FB account to your app on behalf of him
"Login with FB" is the other way round and is not OAuth: A User
with an FB account is using this data to register AND login to your
app.
The entire flow of the # 2 can be read here.

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