Default Passwords of default users when install

[GerGon]

Hi,
I recently installed linux, but it created several account by default.
Somebody can tellme wich are the passwords?
What happend if a change some passwords of default users...??

Thanks

[Chris Xu]

Can you name a few of the default accounts? Some default accounts are not meant for users to log on with. These accounts are used by the system only.

Chris

[GerGon]

Thanks Chris.
Some of them are: bin, daemon, mail, wwwrun, ldap, sshd, gdm, mailman, pop, etc..

[Chris Xu]

These are system accounts and they are not supposed to logged on by users. Therefore can't change their passwords. In the /etc/passwd file, the lines starting with those accounts (bin) should have something like /sbin/nologin at the end. Don't worry about their passwords get changed.

[GerGon]

Here is the passwd file:
bin:x:1:1:bin:/bin:/bin/bash
daemon:x:2:2:Daemon:/sbin:/bin/bash
lp:x:4:7:Printing daemon:/var/spool/lpd:/bin/bash
mail:x:8:12:Mailer daemon:/var/spool/clientmqueue:/bin/false
wwwrun:x:30:65534:WWW daemon apache:/var/lib/wwwrun:/bin/bash
named:x:44:44:Nameserver daemon:/var/named:/bin/bash
man:x:13:62:Manual pages viewer:/var/cache/man:/bin/bash
uucp:x:10:14:Unix-to-Unix CoPy system:/etc/uucp:/bin/bash
at:x:25:25:Batch jobs daemon:/var/spool/atjobs:/bin/bash
mysql:x:60:2:MySQL database admin:/var/lib/mysql:/bin/false

What do those lines mean?
With false at end, not password needed??

[Chris Xu · Accepted solution]

By saying "don't worry about...", I assume you are the admin of the system, and you won't change the passwords yourself!! As root, you have the power to change them, though. I meant non-root users would not be able to change them as they can't be logged on as those accounts.

Chris

[Chris Xu]

The second column (: separated) in /etc/shadow should have a * for those accounts. That indicates the accounts are disabled.

Check out this doc:
http://www.tldp.org/LDP/lame/LAME/linux-admin-made-easy/shadow-file-formats.html

[Stuart Browne]

What do the corresponding entries in the '/etc/shadow' say?

The 'x' in the 2nd column tells the password subsystems to use the Shadow password systems.

If the 2nd column in the /etc/shadow file for the corresponding user's line is '!!' or a '*', then the account is disabled (no password will ever encrypt to start with either an '*' or '!!', thus they are locked for login). You should still be able to 'su' to them assuming the shell allows that.

[GerGon]

Thanks to all...