The OAuth2 Authentication extension enables secure single sign-on capabilities for CKAN through industry-standard OAuth2 protocol integration with external identity providers. This comprehensive authentication solution allows organizations to integrate CKAN with existing identity management systems including FIWARE IdM, Google, Microsoft Azure AD, Okta, and custom OAuth2 servers. The extension handles the complete OAuth2 flow including authorization code exchange, token management, user profile synchronization, and secure session management. Users benefit from seamless login experiences without managing separate CKAN credentials while administrators gain centralized user management and enhanced security controls. The system supports automatic user provisioning, role mapping from external systems, and configurable user attribute synchronization including email, names, and organization memberships. Security features include token validation, secure cookie handling, and protection against common OAuth2 vulnerabilities. Essential for enterprise environments requiring centralized authentication, compliance with organizational security policies, and integration with existing identity infrastructure for streamlined user experience.