Description
This article describes the use of RADIUS Chained Authentication in FortiAuthenticator where 3rd Party Multi-Factor Authentication tokens can be used as 2FA.
Scope
FortiAuthenticator.
Solution
RADIUS Chained Authentication is useful for providing and integrating FortiAuthenticator services in an environment where 3rd Party Multi-Factor Authentication tokens are already widely deployed.
The authentication flow will be as follows, using FortiClient as a VPN login:
FortiClient <SSL> FortiGate <RADIUS> FortiAuthenticator <LDAP> LDAP server (user database)
After the LDAP server accepted the authentication, FortiAuthenticator sends an Access-Challenge to the RADIUS client (for a 3rd token that is expected in this configuration). With the Access-Request, a response will be received containing the answer or OTP. FortiAuthenticator sends an Access-request to the remote RADIUS server, expecting an Access-Accept.
For instance, use chained authentication for administrative access to a FortiGate wherein FortiAuthenticator can validate the username/password (Remote LDAP) and rely on the RSA server for token authentication only.
RADIUS Chained Authentication can be created under the FortiAuthenticator Realm.
- Go to Authentication -> User Management -> Realms and create a new entry. Enter the following information:
- Provide a name.
- For User source, select the LDAP server from the drop-down menu.
- Enable 'Chained token authentication with remote RADIUS server'.
- Select the FortiToken server added as a RADIUS server.
- Optionally, it is possible to configure selected groups are applied with chained token authentication.
