Cookie settings, Session Timeouts, and Token Lifespans
Keycloak has a bunch of fine-grain settings to manage browser cookies, user login sessions, and token lifespans.
Sessions can be viewed and managed within the admin console for all users, and individually in the user's account
management pages. This chapter goes over configuration options for cookies, sessions, and tokens.
Remember Me
If you go to the admin console page of Settings->General, you should see a Remember Me on/off switch.
Your realm sets a SSO cookie so that you only have to enter in your login credentials once.
This Remember Me admin config option, when turned on, will show a "Remember Me" checkbox on the user's login page.
If the user clicks this, the realm's SSO cookie will be persistent. This means that if the user closes their browser
they will still be logged in the next time they start up their browser.
Session Timeouts
If you go to the Sesions and Tokens->Timeout Settings page of the Keycloak adminstration console there is a bunch of fine tuning
you can do as far as login session timeouts go.
The SSO Session Idle Timeout is the idle time of a user session. If there is no activity
in the user's session for this amount of time, the user session will be destroyed, and the user will become logged
out. The idle time is refreshed with every action against the keycloak server for that session, i.e.: a user login,
SSO, a refresh token grant, etc.
The SSO Session Max Lifespan setting is the maximum time a user session is allowed to be alive. This
max lifespan countdown starts from when the user first logs in and is never refreshed. This works great with Remember Me
in that it allow you to force a relogin after a set timeframe.
Token Timeouts
The Access Token Lifespan is how long an access token is valid for. An access token contains everything
an application needs to authorize a client. It contains roles allowed as well as other user information. When
an access token expires, your application will attempt to refresh it using a refresh token that it obtained in the
initial login. The value of this configuration option should be however long you feel comfortable with the
application not knowing if the user's permissions have changed. This value is usually in minutes.
The Client login timeout is how long an access code is valid for. An access code is obtained
on the 1st leg of the OAuth 2.0 redirection protocol. This should be a short time limit. Usually seconds.
The Login user action lifespan is how long a user is allowed to attempt a login. When a user tries
to login, they may have to change their password, set up TOTP, or perform some other action before they are redirected
back to your application as an authentnicated user. This value is relatively short and is usually measured in minutes.
Offline Access
The Offline access is the feature described in OpenID Connect specification .
The idea is that during login, your client application will request Offline token instead of classic Refresh token.
Then the application can save this offline token in the database and can use it anytime later even if user is logged out.
This is useful for example if your application needs to do some "offline" actions on behalf of user even if user is not online. For example
periodic backup of some data every night etc.
Your application is responsible for persist the offline token in some storage (usually database) and then use it to
manually retrieve new access token from Keycloak server.
The difference between classic Refresh token and Offline token is, that offline token will never expire and is not subject of SSO Session Idle timeout .
The offline token is valid even after user logout or server restart. User can revoke the offline tokens in Account management UI. The admin
user can revoke offline tokens for individual users in admin console (The Consent tab of particular user) and he can
see all the offline tokens of all users for particular client application in the settings of the client. Revoking of all offline tokens for particular
client is possible by set notBefore policy for the client.
For requesting the offline token, user needs to be in realm role offline_access and client needs to have
scope for this role. If client has Full scope allowed, the scope is granted by default. Also users are automatically
members of the role as it's the default role.
The client can request offline token by adding parameter scope=offline_access
when sending authorization request to Keycloak. The adapter automatically adds this parameter when you use it to access secured
URL of your application (ie. http://localhost:8080/customer-portal/secured?scope=offline_access ).
The Direct Access Grant or Service account flows also support
offline tokens if you include scope=offline_access in the body of the authentication request. For more details,
see the offline-access-app example from Keycloak demo.