[linux-help] Re: passwd files...

[Tom Hull <thull@xxxxxxxxxxx>]

/usr/bin/passwd is the program that you run to change your password,
which is probably stored in /etc/shadow. /etc/passwd is the password
file, which doesn't contain passwords if you have /etc/shadow.

The 's' tells you that the setuid bit is set. Since /usr/bin/passwd
is owned by root, when you run it its effective user id is root,
which gives it permission to change /etc/shadow (or /etc/passwd).
This is reasonable, because /usr/bin/passwd has been written to
implement its own security; i.e., even though it runs as root, it
doesn't allow you to do anything that you shouldn't be able to do.

You might try running some commands like:

  file /etc/passwd /usr/bin/passwd
  man 1 passwd
  man 5 passwd

Also, man 1 ls will explain the permissions encoding for ls(1).

"Lrs v.d.Ast" wrote:
> 
> I notice on my Linux box two different passwd files:
> /etc/passwd
> -rw-r--r--    1 root     root          923 May 24 19:56 passwd
> 
> /usr/bin/passwd:
> -r-s--x--x    1 root     root        12244 Feb  7 16:20 passwd
> 
> What are they doing? I know the "s" has something to do with sticky bit
> stuff. Can someone explain?
> 
> Lrs v.d.Ast
> 
> -- This is the linux-help@xxxxxxxxx list.  To unsubscribe,
> visit http://tmp2.complete.org/cgi-bin/listargate-aclug.cgi

-- 
/*
 *  Tom Hull * thull@xxxxxxxxxxx * http://www.ocston.org/~thull/
 */

-- This is the linux-help@xxxxxxxxx list.  To unsubscribe,
visit http://tmp2.complete.org/cgi-bin/listargate-aclug.cgi