Users

Linux

@see User groups, Some useful password policies, Debian libpam-pwquality man

To create a new user you can use the low level utility useradd or the more user-friendly utility adduser which is basically a frontend for useradd. When using adduser you will be prompted to enter some information about the new user (only the password in mandatory).

adduser username

Similarly to adding a user, to delete one you can use the low level utility userdel or the more user-friendly deluser utility which is basically a frontend for userdel.

deluser username

When using deluser you have access to the following flags flags:

• –remove-home: Removes the home directory of the specified user.
• –remove-all-files: Removes all the files belonging to the specified user including its home directory.

To set a user’s password as expired an thus forcing the user to change it on next login run the following command:

passwd --expire

or

passwd -e

Password policies

It is a good practice to set a periodic expiration policy for user password to do this you can use the following options of the /etc/login.defs configuration file:

#
# Password aging controls:
#
#	PASS_MAX_DAYS	Maximum number of days a password may be used.
#	PASS_MIN_DAYS	Minimum number of days allowed between password changes.
#	PASS_WARN_AGE	Number of days warning given before a password expires.
#
PASS_MAX_DAYS	30
PASS_MIN_DAYS	2
PASS_WARN_AGE	7