Flutter/Adonis server and Google auth - flutter

I have API server written with Adonis JS (it handles REST calls, auth, contain DB). When user login/register successful server return opaque access token.
I need to create Flutter App and it should use existing server. Also i need to add social authentication (google, twitter, facebook). I'm thinking of creating user on my server when social API return user credentials.
But i'm totally confused with the way it should work. How to initiate process of social login (from app or from server?). Who should handle redirects/callbacks from auth app. How to handle case when created user login again with social app.
I will appreciate if someone can describe that process (general overview).
Thank you!

Related

Keycloal Social Login and Custom Login Authenticator

I am using keycloak as security layer and working towards enabling social login.
Social login was working and I was able to integrate Facebook with just configurations using the doicuments.
However I have a requirement where in I need to provide an API end points for the same.
Our mobile devices will be communicating to facebook via the app and will have the token from the facebook (Implicit Flow).
I will then be exchanging the token with keycloak for the keycloak access token.
I have two questions:
Is this approach correct? If not why?
How can I achieve this?
I was thinking of writing a custom authenticator (Am not sure if thats the right approoach as I have to register user are well if FB Access token user is not available with us (We can afford to login user and with jsut emailID as we can onbaord new users later)
I am blocked because authenticator is not working with any build from 2.4.0 onwards
Let me know if my approach is correct and if so how to proceed about it.

How to secure REST service that login from third parties

I have a REST service that my mobile app uses to authenticate when the users click on the Facebook or Google icons.
The service accepts the user's id from the provider and checks if it exists on the database and then issues the access_token to be used for the other methods.
The problem is that I just thought that it could be pretty easy for someone to intercept the calls and discover which service authenticates and what the user id is and then call it with to get a token.
How can I avoid this?
I think you just need to separate the authentication and authorization functions. You can let Google (Google Sign-In) handle authentication. If you follow the API they will securely authenticate the user and send you the token which you can validate.
Once you know who they are for sure, your site can safely authorize that user approriately. For example, they might be an existing user, need to make an account, be an administrator. You can make those authorizations on your site based on the user authenticated by Google (in my example).
Twitter, Facebook and others do the same. Also see OpenID Connect.

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.

Can my web service api call facebook/google oauth2 on behalf of another web service?

I'm building a web service for use as an api component in web sites or apps built by others.
I am building a set of functionality that my clients can use on their sites for their users, but which are served by my application.
One of these services is user login. I intend to support multiple types of logins, and provide the client application a user token once the user is logged in. So the client application only has to implement one login interface, but they get a variety of oauth2 strategies for it.
To make this work with their google or facebook accounts, they would have to provide my app with their application id and secret key. Entering a secret key on someone else's site, even for integrating with your own site seems dangerous. They call it a "secret" key for a reason.
I have found one web service which seems to be doing something similar to what I am planning to do:
https://www.authic.com/documentation/google_oauth2
They have a configuration page for client accounts where the user enters oauth2 credentials to enable the Authic oauth2 login pages on behalf of the client app.
What are the security concerns to be aware of with this kind of service, and can the client app use a service like this safely? If it can be used safely, what is required for safe use? I think the app doing the oauth2 interface would be able to do other things on behalf of the client app, since it has an app secret, and the client app owners would have to trust that this was not happening.
The alternative to this strategy seems to be using my own application id with oauth2, and having the client apps redirect to my app's login page. Then the user will see the oauth2 permissions page with my app's logo instead of the app they were intending to log in to.

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.