GitLab authentication and authorization

GitLab integrates with a number of OmniAuth providers, and the following external authentication and authorization providers:

note
UltraAuth has removed their software which supports OmniAuth integration. We have therefore removed all references to UltraAuth integration.

SaaS vs Self-Managed Comparison

The external authentication and authorization providers may support the following capabilities. For more information, see the links shown on this page for each external provider.

Capability SaaS Self-managed
User Provisioning SCIM
SAML 1
LDAP 1
SAML 1
OmniAuth Providers 1
User Detail Updating (not group management) Not Available LDAP Sync
Authentication SAML at top-level group (1 provider) LDAP (multiple providers)
Generic OAuth2
SAML (only 1 permitted per unique provider)
Kerberos
JWT
Smartcard
OmniAuth Providers (only 1 permitted per unique provider)
Provider-to-GitLab Role Sync SAML Group Sync LDAP Group Sync
SAML Group Sync (GitLab 15.1 and later)
User Removal SCIM (remove user from top-level group) LDAP (remove user from groups and block from the instance)
  1. Using Just-In-Time (JIT) provisioning, user accounts are created when the user first signs in.

Change apps or configuration

When GitLab doesn’t support having multiple providers (such as OAuth), GitLab configuration and user identification must be updated at the same time if the provider or app is changed.

These instructions apply to all methods of authentication where GitLab stores an extern_uid and it is the only data used for user authentication.

When changing apps within a provider, if the user extern_uid does not change, only the GitLab configuration must be updated.

To swap configurations:

  1. Change provider configuration in your gitlab.rb file.
  2. Update extern_uid for all users that have an identity in GitLab for the previous provider.

To find the extern_uid, look at an existing user’s current extern_uid for an ID that matches the appropriate field in your current provider for the same user.

There are two methods to update the extern_uid:

  • Using the Users API. Pass the provider name and the new extern_uid.
  • Using the Rails console:

    Identity.where(extern_uid: 'old-id').update!(extern_uid: 'new-id')`