pam_unix.so options

[Scott Henson]

Zach wrote:

>Hi,
>
>I posted this question a while back, but didn't get much response.
>
>Can anyone point me to documentation on the options to pam_unix.so? 
>Specifically, I'm looking for details on the "obscure" option as well
>as the "min" and "max" options, both of which are used in Ubuntu's
>pam.d passwd config file.
>
>I've checked the pam system administrator's guide,
>http://www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam.html,
>which is dated 2002, and these options are not documented there.  Also
>there does not appear to be a man page for pam_unix.so.  I've checked
>the Linux Documentation Project, and while there is a howto on user
>authentication, it doesn't go into the various options to this module.
>  
>

Pam have never really been well documented, at least as far as Ive been 
able to find.  There is some basic documentation in a pam doc package 
that you can install, but I'm pretty sure its the same as what you found 
on kernel.org.  Beyond that, all you really have is the source.  Its 
unfortunate, but I find myself going to the source a lot when dealing 
with pam.  Its especially cute when the documentation says one thing and 
you bang your head against the configuration files for a while before 
looking at the source and finding out that the documentation is just 
wrong. 

Pam is really good, but unfortunately it can be really obscure.  I would 
suggest only messing around with its configurations if you really need 
to and you really understand what your doing.  You can introduce some 
very hard to diagnose problems by messing around with it.