{kib} supports the following authentication mechanisms:
- Basic Authentication
- SAML Single Sign-On
==== Basic Authentication
Basic Authentication requires a username and password to successfully log in to {kib}. It is enabled by default and based on the Native security realm provided by {es}. For more information about Basic Authentication and built-in users, see {xpack-ref}/setting-up-authentication.html[Setting Up User Authentication].
==== SAML Single Sign-On
SAML authentication allows users to log in to {kib} with an external Identity Provider, such as Okta or Auth0. Make sure that SAML is enabled and configured in {es} before setting it up in {kib}. See {xpack-ref}/saml-guide.html[Configuring SAML Single-Sign-On on the Elastic Stack].
Set the configuration values in `kibana.yml` as follows:
. The Identify Provider sends authentication requests to the `Assertion Consumer Service` endpoint that {kib} exposes through a "non-safe" `POST` HTTP method. This does not include CSRF protection HTTP headers specific to {kib}. You must disable the CSRF check for this endpoint.
. Sometimes {kib} is behind a reverse proxy so that the user-facing {kib} protocol, hostname, and port are different than what is known to {kib}. If this is your case, update the following settings:
IMPORTANT: The {kib} user-facing origin should be the same in {kib}, {es}, and the Identity Provider SAML configuration.
Users will be able to log in to {kib} via SAML Single Sign-On by navigating directly to the {kib} URL. Users who aren't authenticated are redirected to the Identity Provider for login. Most Identity Providers maintain a long-lived session—users who logged in to a different application using the same Identity Provider in the same browser are automatically authenticated. An exception is if {es} or the Identity Provider is configured to force user to re-authenticate. This login scenario is called _Service Provider initiated login_.
NOTE: Some Identity Providers support a portal or dashboard from which users can open an application that is integrated with the Identity Provider. This login scenario is known as _Identity Provider initiated login_, and {kib} has limitations with this scenario. Users cannot open {kib} in multiple tabs from the Identity Provider portal in the same browser context if an active {kib} session exists. No issues exist if users open {kib} in multiple tabs using _direct_ {kib} URL.
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===== Access and Refresh Tokens
Once the user logs in to {kib} via SAML Single Sign-On, {es} issues access and refresh tokens that {kib} encrypts and stores them in its own session cookie. This way, the user isn't redirected to the Identity Provider for every request that requires authentication. It also means that the {kib} SAML session depends on the `xpack.security.sessionTimeout` setting and the user is automatically logged out if the session expires. An access token that is stored in the session cookie can expire, in which case {kib} will automatically renew it with a one-time-use refresh token and store it in the same cookie.
{kib} can only determine if an access token has expired if it receives a request that requires authentication. If both access and refresh tokens have already expired (for example, after 24 hours of inactivity), {kib} initiates a new SAML "handshake" and redirects the user to the Identity Provider. Depending on {es} and the Identity Provider configuration, the user might be asked to re-enter credentials.
If {kib} can't redirect the user to the Identity Provider (for example, for AJAX/XHR requests), an error indicates that both access and refresh tokens are expired. Reloading the current {kib} page fixes the error.
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===== Local and Global Logout
During logout, both the {kib} session cookie and access/refresh token pair are invalidated. Even if the cookie has been leaked, it can't be re-used after logout. This is known as SAML "local" logout.
{kib} can also initiate a SAML "global" logout or _Single Logout_ if it's supported by the Identity Provider and not explicitly disabled by {es}. In this case, the user is redirected to the Identity Provider for log out of all applications associated with the active Identity Provider session.
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===== SAML and Basic Authentication
SAML support in {kib} is designed to be the primary (or sole) authentication method for users of that {kib} instance. However, you can configure both SAML and Basic authentication for the same {kib} instance:
The order of `saml` and `basic` is important. Users who open {kib} will go through the SAML Single Sign-On process unless the direct Basic authentication `/login` link is used. This might be the case for {kib} or {es} admins whose accounts aren't linked to the Single Sign-On users database. Or, when the `Authorization: Basic base64(username:password)` HTTP header is included in the request (for example, by reverse proxy).
Basic authentication is supported _only_ if `basic` authentication provider is explicitly declared in `xpack.security.authProviders` setting in addition to `saml`.