As seen in the previous chapters, PAM is a very powerful and flexible framework. Of course, applications that require authentication must be aware of PAM. But most basic applications and utilities in the UNIX and Linux world have been migrated. If you are an application programmer and your application requires authentication, you might wish to dig into the possibilities of PAM.
You can find modules for almost any situation, or maybe a combination of modules can solve your problem. But still you might end up in the situation where you cannot find a suitable module. In this chapter, you will learn how to develop your own modules.