All users and groups in authentik's database are searchable. Currently, there is limited support for filters (you can only search for objectClass), but this will be expanded in further releases.
Binding against the LDAP Server uses a flow in the background. This allows you to use the same policies and flows as you do for web-based logins. For more info, see [Bind modes](#bind-modes).
You can configure under which base DN the information should be available. For this documentation we'll use the default of `DC=ldap,DC=goauthentik,DC=io`.
Users are available under `ou=users,<base DN>` and groups under `ou=groups,<base DN>`. To aid compatibility, each user belongs to its own "virtual" group, as is standard on most Unix-like systems. This group does not exist in the authentik database, and is generated on the fly. These virtual groups are under the `ou=virtual-groups,<base DN>` DN.
-`homeDirectory`: A default home directory path for the user, by default `/home/$username`. Can be overwritten by setting `homeDirectory` as an attribute on users or groups.
A virtual group is also created for each user, they have the same fields as groups but have an additional objectClass: `goauthentik.io/ldap/virtual-group`.
Starting with authentik 2023.6, StartTLS is supported, and the provider will pick the correct certificate based on the configured _TLS Server name_ field. The certificate is not picked based on the Bind DN, as the StartTLS operation should happen be the bind request to ensure bind credentials are transmitted over TLS.
Starting with authentik 2023.6, code-based authenticators are only supported when _Code-based MFA Support_ is enabled in the provider. When enabled, all users that will bind to the LDAP provider should have a TOTP device configured, as otherwise a password might be incorrectly rejected when semicolons are used in the password.
For code-based authenticators, the code must be given as part of the bind password, separated by a semicolon. For example for the password `example-password` and the code `123456`, the input must be `example-password;123456`.
SMS-based authenticators are not supported as they require a code to be sent from authentik, which is not possible during the bind.
This mode uses the same logic as direct bind, however the result is cached for the entered credentials, and saved in memory for the standard session duration. Sessions are saved independently, meaning that revoking sessions does _not_ remove them from the outpost, and neither will changing a users credentials.
Every LDAP search request will trigger one or more requests to the authentik core API. This will always return the latest data, however also has a performance hit due all the layers the backend requests have to go through, etc.
#### Cached search
In this mode, the outpost will periodically fetch all users and groups from the backend, hold them in memory, and respond to search queries directly. This means greatly improved performance but potentially returning old/invalid data.
