Google OAuth2 - tokens, on-line, offline, adding scopes incrementally - access-token

Trying to organize this question into something clear. We are integrating Google for Work into our application, to use login, Google+, and eventually Contacts, Calendar, etc. As is recommended by Google and everything I have read, we are going to use incremental access, only adding scopes when they are needed. We are a PHP shop.
But, we will also be needing offline access, as our Contacts (and eventually Calendar) access will be synchronizing with our internal database.
We currently capture the Access and Refresh Tokens when doing the initial link, and store them locally, so that we can re-authorize at any time by using the Refresh token whenever the Access token expires. This is working correctly.
Questions:
a) when adding the incremental scopes for Contacts, the documentation says we need to call the gapi.auth.signIn() function in the page javascript with the new scopes. This is working on the page where we are allowing folks to manage settings. In the original login function callback, I save the Access Token and scopes with an Ajax call that uses the access code passed into the callback, and calls the Google_Client authenticate() function to get the access code and scopes... but at that point, the information I get back does not have the new scopes. Why? Do I have to re-extend the scopes every time the page is drawn?
b) since we are going to have a batch process do the contact synchronization, do I need to get an entirely different access token with access_type=offline, or can I use the current access token (properly extended with the new scopes). Can an off-line access token be used for on-line access as well as off-line? Or vice-versa?

For your questions:
a) have you used the parameter "include_granted_scopes"? as mentioned here:
https://developers.google.com/accounts/docs/OAuth2WebServer#incrementalAuth
b) When you request an offline access token, the response contains the access token and refresh token. so you can refresh the access token after it expires without having the user grant the permissions again.
online access token and offline access token work for the same.
the difference between both its the capability to refresh the access token when it expires without involving the user. Which is the functionality for the offline type.
The online access token doesn't mean that it works for your client-side authentication (done in the browser) and the offline works for the server-side.
You mentioned that you can get an access token, refresh token and authorization code from the client-side of your app. You could send that information to your server and make api calls from there, although this is not a good practice.
I would suggest that you do the OAuth Flow in the server side and from there manage the users information and API calls.
Here you can find the documentation on both Web server applications and Client Side applications.
Hope it's clearer.

Related

Elixir Phoenix Absinthe GraphQL API authentication in both web and mobile app's

I'm working on an Absinthe GraphQL API for my app. I'm still learning the procedure(so please go easy on me).
I've a Absinthe/GraphQL MyAppWeb.schema.ex file in which I use for my queries and mutations. My question is how do I use this API for authenticating the user on both Mobile and Web app?
How do set a cookie(httpOnly & secure) in my web app and access/refresh tokens in a single Absinthe API to serve my website and mobile app. Basically what I'm trying to learn is how do I authenticate the user based on specific platform.
If my question sounds bit confusing, I would be happy to provide more information related to my question. I would really be grateful if someone could explain the procedure, I've been very stuck on this for a while.
I would avoid using authentication mechanisms provided by absinthe(if there are any). Depending on what front-end you are using, I would go with JSON API authentication. The flow on server goes the following way:
Create a endpoint for login that will receive a user and password and will return a refresh token.
Create a endpoint for exchanging refresh token for access token.
Use a library like guardian to generate your refresh/access tokens.
Create a phoenix plug for authentication that will check your tokens, guardian has some built-in plugs for this.
Now on device you have to implement:
Ability to save refresh and access token on device.
Have a global handler for injecting access token on authorized requests.
Have a global handler for case when access token is expired. (you usually check if your request returns Unauthorized, then you should request a new access token from the server using your refresh token)
This seems like a crude implementation, however I would advise in implementing your system instead of using a black box library that you have no idea how it works under the hood.

How to invalidate mobile personal access token after backend deletion?

I am using Laravel as my backend together with Sanctum which generates personal access token for mobile users. For my mobile application I am using flutter.
To authenticate users they login with their username/password and get a personal access token in return. This works but requires a user to login every time they open the application again so I did what most tutorials suggest which is saving the token on the mobile device using shared preferences/secure storage.
Now comes the question how do you invalidate a user when you remove their token from the backend? On initial login it appears everything is still fine because like in most tutorial I check for the existence of a token. After that whenever I want to make a request which uses the token I obviously run into problems because it not longer exists on the backend.
Most tutorials/guide suggest saving the token and using that a reference to see if the user is logged in or not but this seems flawed because it gives the false impression you actually have a valid token.
My guess is this can be solved by always performing a heartbeat/ping action to check if the current token is valid and if not send them to the login screen instead of simply checking for the existence of the token.
Thoughts on this?
I can suggest a hack or trick here in every launch of the app you can send a request to an API to check if the user's token is valid or not and if it is valid then you can continue the app otherwise force the user to login and generate new token this way your app will be secure via server / API.
For this, you can store the user's secret token in the database and check it via HTTP API call and send a response from the API accordingly and check the response in app and do the next operation according to the response you get.
I don't know if this is a great way of doing this job but it is a kind of hack/trick to achieve what is needed.
Thanks

What to return after login via API?

I'm creating an API server which will be consumed by a mobile app that I will work on later. I have yet to see any reference of API best practices related to user flow and returned data even after searching for several hours.
My question is whether the login response of an API should return the a personal access token with the refresh token along with the user info? Or should I just return the token and make another API call for getting the user info.
I could just do what I have in mind but I'm trying to learn the best practices so that I don't have to adjust a lot of things later.
I need suggestions as well as good references related to my question.
Thank you.
It depends on what you are using for your authentication. If you are using libraries like Laravel Passport or JWT, you can have the token endpoint which returns the access token, refresh token, validity period and the token type (Bearer). You can then have an authenticated endpoint which will be used to get a user's profile based of the token passed in the request header.
However, if you go through the documentation for those libraries, in most there is an allowance to manually generate a token. You can use this in a custom endpoint that will return the token as well as the user profile Passport Manually Generate Token.
If you are using JWT, you can also embed a few user properties in the token itself. The client can the get the profile info from the JWT itself without having to make a round trip to the server. Passport ADD Profile to JWT
If you have a custom way in which you are handling authentication, you can pass the token as well as the user profile in the same response.
In the end, it's up to you to decide what suits you best.
Have you looked at OpenID Connect? It's another layer on top of OAuth 2.0 and provides user authentication (OAuth 2.0 does not cover authentication, it just assumes it happens) and ways to find information about the current user.
It has the concept of an ID_token, in addition to the OAuth access token, and also provides a /userinfo endpoint to retrieve information about the user.
You could put user information in your access token, but security best practice is to NOT allow your access token to be accessible from JavaScript (i.e. use HTTP_ONLY cookies to store your access token).

Open ID Connect Session Management Access/Refresh Token vs Session iFrame

We have a web app in which we allow users to log into the app using any Open ID provider(e.g. Okta, Google, Facebook etc.). We want to implement the correct Open ID Connect prescribed methodology/workflow to keep the user logged into the site.
The existing implementation, looks at the expiry of the Access Token then if it's close to expiry uses a Refresh Token to get a new Access Token to keep the user logged in. I feel like this is wrong. When a user logs in to the web app, the Identity Token is used to Authenticate the identity of the user using the Authorization Code workflow. The Access Token and Refresh Token are stored on the server side. Periodically, the Refresh Token is used to get new Access Tokens to keep the user logged into the site. I believe this is a security risk because -
Imagine if a user is logged onto his OP account in a browser. He opens up Sky and is directly logged into MP because he’s already logged into MP. He then in a separate tab, logs out of his OP account. He will continue to be logged into MP for days on the basis of this Refresh Token/Access Token mechanism! Isn’t this a security risk?
If feel like the correct way to go about this is to use Session Management using iframes as prescribed here on OIDC -
https://openid.net/specs/openid-connect-session-1_0.html
For more context, when a user logs into our WebApp we pull data from the OP's UserInfo endpoint to create a profile within our WebApp and set permissions/roles within our app based on data sent over from the OP's UserInfo endpoint. We continue doing this periodically. For this purpose, I feel like using the Access Token(and using the Refresh Token to get new Access Token) to access the UserInfo API is correct because it conforms to the OAuth 2.0 concept of protecting/authorizing API/Resource endpoints using Access Tokens.
I want to know if this is indeed the correct way to manage how a user should be logged in when supporting Open ID Connect.
I think the first question is whether you want to bind the lifetime of an OpenID Connect provider Single Sign On session with the session of your application. You just want to authenticate a user using their OpenID Connect service. If I logout of Google, I expect to be logged out of GMail, but not a third-party application that used Google for authentication. Would you like to implement Single Sign Out as well?
But if I wanted to be logged out when you logout of the OpenID Connect provider, I would implement the OpenID Connect Session management. There is one thing good to be aware of when using iframes and cookies - browsers have an option to "Block third-party cookies" (that's how Chrome calls it), it's turned off by default, but as far as I know, it disables the SSO functionality when turned on.
I'm not sure why you request the userinfo endpoint periodically. If you just want to check whether the access token is still valid, you could also use the token introspection endpoint.
For security concerns, I would suggest you to read the OAuth 2.0 for Browser-Based Apps RFC. It recommends using the auth code flow with PKCE instead of the implicit flow. With the implicit flow, access tokens transported in redirect URLs stay in network and browser caches and can be used right away by an attacker. The auth code with PKCE needs a code_verifier (one-time secret) in order to be exchanged for tokens. So I would first check how the providers work with a configuration you choose and if it's even supported.

Alexa skill account linking with Google APIs credentials, problem refreshing token

I'm having some problems with the Alexa account linking authorization.
These are the steps I followed:
I got the credentials (client id, client secret...) from the Google Cloud Console
Setup on the Alexa Developer Console, using 'Auth Code Grant' as authorization grant type
Activated the skill on my Alexa application and successfully logged in with my Google account
Now I got the access token in the request, in handler_input.request_envelope.context.system.user.access_token
The problem is that the access token expires after one hour and Alexa does not manage the refreshment of the token.
What should I do to avoid having to ask my users to login every time after one hour? Should I use Implicit grant as authorization type? Should I get a refresh token somehow?
Additional info: it's a custom skill that connects to an AWS Lambda using Python3
While #pinoyyid's answer was correct, it didn't provide a solution so I'm posting one for future reference.
The problem was indeed that Amazon servers did not receive a refresh token from Google, thus making it impossible to refresh the access token after its expiration time of one hour.
Following this link and other Amazon forum posts, I got to a working solution.
Amazon Alexa developer console 'Account Linking' configuration:
Authorization grant type: Auth Code Grant
Authorization URI: https://accounts.google.com/o/oauth2/v2/auth?access_type=offline (even though the one from the google credentials was not v2, it shouldn't make a difference)
The access type is very important because, as documentation goes:
Set the [access_type] value to offline if your application needs to refresh access tokens when the user is not present at the browser. [...] This value instructs the Google authorization server to return a refresh token and an access token the first time that your application exchanges an authorization code for tokens.
Access Token URI: https://accounts.google.com/o/oauth2/token
Client ID & Secret: downloaded on Google Cloud Platform
Client Authentication Scheme: HTTP Basic
Domain List: google.com and googleapis.com
Default access Token Expiration Time: left empty
Now, after doing this and saving the configuration, be aware that you might not notice the change, as, from here:
When Alexa uses the refresh token to retrieve a new access token for an existing user, Alexa uses the access token URI that was configured at the time the user linked their account. Therefore, if you change the access token URI later, users who linked their accounts before continue to use the old URI for retrieving updated tokens. The users must unlink and re-link accounts to switch to the new access token URI.
So, in order to complete the procedure:
Deactivate your skill
Go to the Google third party applications that have access to your data and remove your Google Project associated
Reactivate your skill and login again (if done correctly it should ask you the permissions for the scope you specified in the Alexa developer console again
Done! after one hour you should re-try and it should have a renewed access token
Additional Info
I found that many suggested to retrieve the refresh token, I don't believe this is possible because, even if Google sends it, it's Amazon that stores it and uses it to refresh the access token.
EDIT:
This works fine for developing and testing but I discovered here that for publication purposes you must own the landing page that you redirect your users to. For me it was just necessary to create a simple HTML page hosted in a public S3 bucket that would redirect the request to the Authorization URI I wrote before, while the Access Token URI must remain the Google one.
Have you read https://developer.amazon.com/docs/account-linking/configure-authorization-code-grant.html ?
My guess is that the Refresh Token is missing because you have already auithorised the app. The RT is only issued once. Try going into https://myaccount.google.com/permissions?utm_source=google-account&utm_medium=web to revoke the permission and try again.

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