Yubikey-php is a project mainly written in PHP, it's free.
Yubikey PHP Class
Version 0.96
Included are two files:
Yubikey.php - The Yubikey class
yubikeytest.php - A sample php script which uses the class.
Pretty self explanitory. Open 'yubikeytest.php' and change the $apiID and $signatureKey variables to the id and key you got from Yubico. If you have no idea what I'm talking about, go to:
https://api.yubico.com/get-api-key/
Enter your email and your Yubikey output and Yubico will supply you with an id and key.
The 'Yubikey.php' file has instructions at its head.
Tom Corwine [email protected]