Add password conversation.

[adiroiban]

Scope

I made those changes while trying to write a test pam module to help with my automated tests.

It updates the README and adds password conversation so that you can check the password.

Changes

Not all pam modules are located in /lib/security/.
On my Ubuntu 14.04 they are in /lib/x86_64-linux-gnu/security/

I find the putting them in /tmp/ is easier as the pam conf file allow absolute paths.

To link it to pam you need to pass -lpam

Rather than messing with common-auth or any existing service I think that it is better to create a dedicated pam service configuration.

I have extended pam_test to also get the service name as argument.

I found that the auth check part from the test was strange... please check that the changes from test.c are ok

Feel free to reject it or to merge only part of this PR.

How to test

Folllow the insctruction from the README file

allowed account test-user/test-pass

Thanks!

[beatgammit]

Thanks for the PR! I haven't touched this in like forever (mostly because I stopped working on the project I was using this for), and the original intention was as an example, so I'll have to review this to make sure it's not becoming too application-y.

I'll take a look at this once I get some time. I can't promise a time frame though.

[adiroiban]

NP.

Just some more feedback. I tried the code on AIX/HPUX/Solaris and it failed miserably with both gcc and proprietary compilers :(