Guster

@Jnchi You can use [web.archive.org](web.archive.org) - [Writing PAM Modules, Part One](https://web.archive.org/web/20101219134423/http://linuxdevcenter.com/pub/a/linux/2002/05/02/pam_modules.html?page=1) - [Writing PAM Modules, Part Two](http://web.archive.org/web/20111015004124/http://linuxdevcenter.com/pub/a/linux/2002/05/23/pam_modules.html) - [Writing PAM Modules, Part Three](https://web.archive.org/web/20180101164802/http://www.linuxdevcenter.com/pub/a/linux/2002/05/30/pam_modules.html)