Installing PAM

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It's probably pretty clear that PAM is a low-level system. That is, PAM is used by many other programs, and so it's an important part of a distribution. PAM is really at the same level as the other core system libraries, such as the GNU Project's glibc libraries or XFree86.

For this reason, the installation of PAM really has to be done by the distribution vendor. To see why, consider what an administrator would have to do to install PAM. Obviously, the first step would be to install the PAM libraries themselves; however, after that any program that is to use PAM would have to be recompiled to do so. This means that a potentially significant number of applications would have to be reinstalled. This is quite a bit of effort, and so if PAM is to be used on a distribution, it has to be installed early in the process.

Therefore, this book will not describe the process of installing PAM itself. Really, it's a simple process, and it's similar to the installation of any other software package. However, it involves so much effort and low-level "hacking" of the Linux distribution that it's a task best left to the vendor. If your distribution comes with PAM installed, then the following sections might be of interest. If it doesn't, then it's probably not worth trying to install it.

Of course, this is a chapter on installing software, right? If I'm not going to discuss the installation of PAM, why even mention it? The reason is that the installation of other programs frequently requires interaction with PAM. That is, you may need to do some PAM-related configuration when you install a program that needs to perform user authentication (such as OpenSSH or even the Apache web server if it has the appropriate modules loaded). The next section discusses this task.

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