This extension provides LDAP support for TYPO3 by delegating the authentication of frontend and/or backend users to the centrally-managed directory of your organization. It fully supports OpenLDAP and Active Directory and is capable of connecting securely to the authentication server using either TLS or SSL (ldaps://). In case of use in an intranet environment, this extension is a perfect match since it natively brings Single Sign-On (SSO) capability to TYPO3 without any complex configuration.
Last version compatible with TYPO3 6.2. Various bug fixes for TYPO3 8 LTS. Details on https://forge.typo3.org/projects/extension-ig_ldap_sso_auth/wiki/IG_LDAP_SSO_AUTH_322