KDE-Forum.org

Quoted

The KCheckPass authentication software:
-----------------------------------------

KCheckPass is KDE's authentication program. It is meant to be
used by any software in need of user authentication, most
notably screensavers.

It enhances security be the following means:

- It's only a small program, which is hopefully simple enough to
allow it to be SUID root. Setting it to SUID root is necessary
on Shadow Password systems.
- No other program in need of user authentication, must be
SUID root.
- It provides a single implementation to check passwords. So one
only must take a closer look at KCheckPass to ensure password
security. It's much easier for programs using KCheckPass to
preserve security.


Technique:
----------
KCheckPass is a simple password checker. Just invoke and
send it the password on stdin.

If the password was accepted, the program exits with 0;
if it was rejected, it exits with 1. Any other exit
code signals an error.