How should handle users logout use case when multi

问题:

I am using angular-oauth2-oidc with Identity Server 4.

Users need to Login via OpenId Connect Implicit Flow. My Id and Access token are stored in the web browser localStorage.

When user opens multiple browser tabs and then user logs out from one of the tabs, how should I handle rest of the tabs?

I have tried to catch session_terminated events , and they try to log the user out. However, it does not redirect the user back to the login page.

this.oauthService.events.filter(e => e.type ==='session_terminated')
                  .subscribe(e => {this.oauthService.logout();})

any suggestions? thanks

回答1:

Interesting. It was on my to do list to see how this works with the library anyways.

I had already created a dedicated playground example repo that was perfect for testing this. What I found was that there are two distinct scenarios:

1. The user goes to the IdentityServer themselves, and click log out
2. The user does a Single Sign Out via our own app

Only in the first scenario do you get a session_terminated event. In the second scenario (which you seem to have) you get a session_error event in the second tab because the first tab:

1. Clears your stored tokens
2. Redirects you to the log out page (where you still have to click log out)

You can see as much in these screencaptures:

Scenario 1: log out explicitly in a third tab

Scenario 2: log out from the app

So I think your solution is to also hook into session_error, or something similar.

---

Footnote: thinking some more about the above, I reckon that other workarounds might also be possible by listening to localStorage events, and notice when the access_token is being cleared by another tab.

回答2:

This is what the OIDC session management spec is all about. You can be notified on the client side when their IDP session changes/ends and then react accordingly.

http://openid.net/specs/openid-connect-session-1_0.html#ChangeNotification

Works well, doesn't have any network overhead and gives you full control over what to do when the condition is detected.

回答3:

I've experienced a similar issue: using angular-oauth2-oidc with default storage (sessionStorage) leads to the behavior that if a user opens a new Tab (Tab B), he is being logged-in again with a new Token. When he logs-out on Tab A, the token stored in sessionStorage of Tab B is still there, of course.

Using localStorage has the disadvantage that the token is persisted even if the browser is closed (kinda "keep me logged in").

What I've done to overcome this is using an own OAuthStorage that internally uses sessionStorage but if the user logs out, it sends an event to all other open Browser-Tabs and triggers a clearing up of the session-storages there.

See the accroding gist