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LDAP Provider

You can configure an LDAP Provider for applications that don't support any newer protocols or require LDAP.

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Note: This provider requires the deployment of the LDAP Outpost

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.

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.

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Note: Every LDAP provider needs to have a unique base DN. You can achieve this by prepending an application-specific OU or DC. e.g. OU=appname,DC=ldap,DC=goauthentik,DC=io

The following fields are currently sent for users:

  • cn: User's username
  • uid: Unique user identifier
  • uidNumber: A unique numeric identifier for the user
  • name: User's name
  • displayName: User's name
  • mail: User's email address
  • objectClass: A list of these strings:
    • "user"
    • "organizationalPerson"
    • "goauthentik.io/ldap/user"
  • memberOf: A list of all DNs that the user is a member of
  • 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.
  • ak-active: "true" if the account is active, otherwise "false"
  • ak-superuser: "true" if the account is part of a group with superuser permissions, otherwise "false"

The following fields are current set for groups:

  • cn: The group's name
  • uid: Unique group identifier
  • gidNumber: A unique numeric identifier for the group
  • member: A list of all DNs of the groups members
  • objectClass: A list of these strings:
    • "group"
    • "goauthentik.io/ldap/group"

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. The virtual groups gidNumber is equal to the uidNumber of the user.

Additionally, for both users and (non-virtual) groups, any attributes you set are also present as LDAP Attributes.

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Starting with 2021.9.1, custom attributes will override the inbuilt attributes.

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Starting with 2023.3, periods and slashes in custom attributes will be sanitized.

SSL / StartTLS​

You can also configure SSL for your LDAP Providers by selecting a certificate and a server name in the provider settings.

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.

This enables you to bind on port 636 using LDAPS.

Integrations​

See the integration guide for sssd for an example guide.

Binding & Bind Modes​

All bind modes rely on flows.

The following stages are supported:

  • Identification

  • Password

  • Authenticator validation

    Note: Authenticator validation currently only supports DUO, TOTP and static authenticators.

    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.

  • User Logout

  • User Login

  • Deny

Direct bind​

In this mode, the outpost will always execute the configured flow when a new bind request is received.

Cached 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.

Searching & Search Modes​

Any user that is authorized to access the LDAP provider's application can execute search the LDAP directory. Without explicit permissions to do broader searches, a user's search request will return information about themselves, including user info, group info, and group membership.

Users and roles can be assigned the permission "Search full LDAP directory" to allow them to search the full LDAP directory and retrieve information about all users in the authentik instance.

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Up to authentik version 2024.8 this was managed using the "Search group" attribute in the LDAP Provider, where users could be added to a group to grant them this permission. With authentik 2024.8 this is automatically migrated to the "Search full LDAP directory" permission, which can be assigned more flexibly.

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.

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.