we are running into an issue that once our users are login in the app and are authenticated thru the oauth flow the authentication page is never being displayed again, in that way user cannot switch account if needed. We are using a popup display mode (which does not provide options to switch user) and "switch user" small button in top right side of the screen is not appearing in our mobile small screen devices (as Iphones). We tried the auth_type=reauthenticate but it does not provide any option to switch user in popup mode either. We can´t control user´s cookies as well so there is not how to delete them. Is there any way to always ask user to reathenticate during all oauth requests allowing user to switch accounts?
If Facebook has implemented OpenID Connect correctly, try to add prompt=login or prompt=select_account to your authorization request. See "3.1.2.1. Authentication Request" in OpenID Connect Core 1.0 for details.
Related
Using this page: https://developers.google.com/identity/sign-in/web/sign-in
It's really easy to add a button to a page for a client side only login with Google.
On Clicking the button, the user is presented with a screen like this:
There are 2 ux_mode for this button: "popup" and "redirect":
https://developers.google.com/identity/sign-in/web/reference
My question is about ux_mode=popup specifically, where the originating page doesn't change, and all the login flow is handled in a separate popup window.
Imagine a good app is published. It seems like an attacker could clone the app, present it to a user. The user thinking it's good app would login and the attacker would have a way to grab a valid token from the user for good app.
Now I understand that in that mode (popup), the IDP (Google) will reject anything that doesn't come from an Origin that is not part of the explicit list of redirect URIs set in the configuration of the project.
But is that the only thing that prevents this? I have read again and again that one should not rely on CORS for the security. Also I'm not sure but it seems that it can be circumvented with a little bit of crafting.
Is there another aspect of the security of this login flow I am missing?
I do not know google implementation but from OAuth 2 point of view:
1/ "The user thinking it's good app" user should check the address bar and a green lock in his browser. It is considered as a users responsibility.
2/ you registered redirect uris which are checked when client is trying to get access token. So google will reject to generate and redirect users browser to malicious app with the token.
3/ browser will reject any communication between popup window and other webpages since they are not same origin. This is called same origin policy and is considered as important security feature of a browser.
In general: app location/uri/origin/domain (as you want) is what identifys your app and security is based on that.
Hope it helped.
I am writing a Reddit client that uses OAuth to authenticate the user. One of the features I would like to implement is the ability to use multiple accounts simultaneously. This requires the user to authorize my client on each account they want to use. The problem I'm running into is that if the user is already logged into Reddit in their browser, when I pop a browser to perform the auth, it will have them authenticate my client against their currently logged in user.
Is there a way to force the user to re-enter their credentials? I would rather not have to put some kind of disclaimer on my Add Account screen that says "Please log out of Reddit in any open browser windows".
I tried opening the Reddit login page in a WebView so the request is sandboxed, and while that worked, it gives the user access to the entire login page (including all the links that navigate to elsewhere on the site). I don't mind that experience when I'm popping an external browser, but in an embedded WebView I really just want to present a username and password box along with the OAuth validation prompt.
Note: I do kind of prefer the embedded experience because it doesn't interfere with the users existing browser cookies, I just don't like how cluttered the login page is this way and I'm not sure how to prevent the user from navigating away from login. Also, for completeness, this is a UWP app, though this problem is largely technology independent.
The problem I'm running into is that if the user is already logged into Reddit in their browser, when I pop a browser to perform the auth, it will have them authenticate my client against their currently logged in user.
It may be caused by the authorization server. If so, we can not do anything in our client app.
But if it is not the server issue, in UWP, there is a WebAuthenticationBroker class witch can help you to authorize your app to access the user info from Resource server by getting a token. You can try to use the class to implement OAuth authorization. You don't need to use the in a WebView so that you can authorize your app with multiple users if you can manage all the user with the token properly in your code logic.
See the Web authentication broker topic and the sample to learn more details.
Short description:
If a user has already granted my application OAuth access to their google profile, I want to spare them of having to press "sign in using google" button every time they land on my home page and log them in automatically.
If user has not granted access yet, I want to present them with sign in options page with "sign in using google" button.
Long description:
I am implementing Google OAuth flow as described on this link:
Using OAuth 2.0 for Web Server Applications
Just for the clarity, the flow in question is as follows:
present (client side) user with "sign in using google" button
after user presses the button, redirect them to google's OAuth 2.0 server, where they allow/deny my application to access their google profile
if user allows access, google redirects them back to my application
my application (server side) uses acquired grant to get access token
my application (server side) access user's profile using acquired access token
I want to achieve the following:
If user has already allowed my application access to their google profile before (either on current computer or some other), I want them to have an impression of being signed in to my application (using google) immediately after they navigate to my application's URL. Without having to click anything.
This is at first glance not a problem. To achieve this, I would automate steps 1 and 2 of the flow described above. User would be redirected to google oauth server automatically - without having to press "sign in using google" button - right after they navigates to application's URL. Google in turn immediately redirects user back to my application with a valid grant (again without requiring any input from the user). The rest remains the same. User would have an impression of being logged in immediately .
This approach has a problem though. If user goes to my page for the first time (not having granted my application access before), they would also be redirected to google OAuth page. But since they haven't granted access yet, and didn't press any sing in button, they would and end up staring at google oauth server page confused having no clue, what is going on.
Is there some API, by which I can detect that user has not yet granted access to my app (and I should present him with sing in button first)?
Please, if your solution would involve some API calls, point me to a HTTP/REST API, as I don't use (and do not want use) any higher level OAuth library.
Thanks.
Add "prompt=none" parameter to your initial OAuth redirect. This way google will not block if user has not logged in or has not granted your app the permissions.
See Chapter 3.1.2.1 of http://openid.net/specs/openid-connect-core-1_0.html#AuthRequest
Short summary of other possible "prompt" values:
none - will not prompt anything, redirects back with error "login_required" or "interaction_required" if silent login is not possible.
login - force the login prompt, even when user is logged-in.
consent - force the consent prompt, even if user has provided consent in the past.
select_account - present account selection prompt.
Google's login integration guide for iOS does not actually describe the possibility of programmatically switching accounts.
My requirement is to allow the user to switch their Google account, but if they choose to cancel the switch then they should stay logged in with their current credentials. Youtube already do this but I can see they're using a custom built screen instead of the default account selection screen.
What I've done so far is to call this when user taps account image
GIDSignIn.sharedInstance().signOut()
GIDSignIn.sharedInstance().signIn()
which prompts the account selection screen each time, with the disadvantage that, of course, if the user cancels, they will be signed out of the app. There must be a way to preserve the authorisation token in the Keychain, but I don't know they key for it in order to trigger the save before displaying the screen. Is there an easier way to go about this?
According to Facebook docs, Facebook login for IOS provide "FBSDKLoginManager" - which directly call into the API to perform login or additional authorizations with your own UI.
https://developers.facebook.com/docs/facebook-login/ios#login-apicalls
If an application uses its own login UI, it can potentially steals user credentials typed into it. That seems violates the purpose of OAuth2.0/OpenID to make authentication mechanisms and credentials independent from the client/app.
I'm wondering why there is a "FBSDKLoginManager" and what is the right use case for it?
The phrase "with your own UI" was referring to the UI elements that trigger the login flow (such as a custom login button). The authentication exchange still occurs over Facebook UI (i.e., the login manager will typically app switch to the native Facebook app if installed, or to the Safari browser).