Re: Start linux without login prompt

From: CoinCoveredEyes (simpleeqbest@hotmail.com)
Date: 02/19/03 

From: simpleeqbest@hotmail.com (CoinCoveredEyes)
Date: 19 Feb 2003 12:22:16 -0800

> > Is there any method to start linux without login prompt?
> > That means login with root without prompting for user and password
> In open source world everything is possible, but I doubt if there's
> any kind of patch or dedicated software (some kind of login not asking
> for password) to do that... well, maybe you'll find something on the
> internet, but besides of that it's hard to find, it's also not the best
> thing to do, it's against unix/linux philosophy.

Philosophy?
Being able to skip login on a single user system is user friendly.

I did this on Slackware 8.0.
Don't have the mods in front of me, but this is what I remember:
I got the agetty source from www.slackware.org.
I added a "-u" flag to agetty. (u for user)
I changed inittab so one agetty would run with "-u guest".
I put a password for guest in /etc/shadow.
I cleared the password for guest in /etc/passwd.
I edited /home/guest/.bashrc to add "startx".

Now the computer boots straight to guest's account
and runs X windows. If the user exits X and logs out,
the agetty program immediately logs back in as guest.
In short, there is no such thing as being logged out anymore.
The user may of course log in as someone else from the
guest account which is chiefly useful for organizational
purposes, not security.
Finally, I made sure that any user could run "halt" and that
"halt" was easily accessed from the menus in X.

For security, I disabled telnet, rsh, etc. I can log in
remotely with ssh, and only ssh. Since ssh uses the /etc/shadow file
I can't log in as guest without the password, which can be
as hard as I want. Agetty, login, and those use the /etc/passwd file.

My thinking is that if anyone has access to the physical hardware,
no cute login/password prompt is going to keep them out.
You would have to encrypt the hard drive to do that.
Otherwise, it is trivial to boot the machine with a floppy or CD
(DemoLinux for instance) and mount the partitions.
It's only a little more work to yank the hard drive out and
stick it in another machine, in case the first machine has
a BIOS password scheme enabled. So why hassle someone who
is right at the console with that nonsense?

This is not much different from users leaving a
computer on and logged in so they don't have to log in all
the time. This scheme allows the users to turn the machine
off and remain logged in, so to speak.

Brent

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