LinOTP is a solution for strong two-factor authentication with one time passwords. It includes a FreeRADIUS plugin, an LDAP schema for OpenLDAP, helper utilities, and a C library for database access. You can use LinOTP to authenticate with any software or hardware token which generates one time passwords according to HMAC-OTP (RFC 4226). For example, it can work with Aladdin eToken PASS and Safeword or LSE MobileOTP. Using the FreeRADIUS plugin, LinOTP provides a way for applications and services to use the OTP authentication. Applications with which it has been used include PAM for local and ssh login, Apache HTTPD, VPN, and Windows Terminal Server (via LSE RadiusGINA).
