LDAP has been the backbone for directory services for decades. It stores user identities, groups, and access rules in a central place. OIDC extends OAuth 2.0 with an identity layer, bringing modern, token-based authentication and single sign-on to web and mobile apps. When you integrate LDAP with OIDC, you bridge old infrastructure with secure, lightweight, web-ready protocols.
LDAP handles the authoritative user store. OIDC lets you authenticate and authorize across distributed services without sharing passwords directly. Instead, it issues signed JSON Web Tokens (JWTs) containing identity claims. Your applications verify tokens rather than query the directory every time. This reduces latency, load, and attack surface.
To connect LDAP and OIDC, you typically run an identity provider (IdP) that supports both protocols. Examples include Keycloak, Auth0 (with LDAP sync), Gluu Server, and ForgeRock. These systems bind to LDAP for user data, then offer OIDC endpoints for client applications. Configuration involves mapping LDAP attributes (like uid, mail, memberOf) to OIDC claims (sub, email, groups). Security best practices include enforcing TLS on LDAP connections, using signed tokens with short expiration, and refreshing claims periodically to reflect directory changes.