yubikey-server-c - 0.5-1.1 main

Yubikeys are USB tokens that act like keyboards and generate one-time
passwords. The tokens are produced and sold by Yubico
.
This is a server that checks the validity of those OTP tokens. There
are servers written in Java and PHP, while this one is written in C
.
It implements the server side of the API as described on
http://www.yubico.com/developers/api/ and can be used with any client
that implements the same API.