How to manage user password expiration information in Linux

Why should I set user password expiration in linux?

 

Setting user password expiration is an important security measure in Linux. Here are some reasons why:

1. Passwords can be compromised: No matter how strong a password is, there is always a risk of it being compromised. By setting password expiration, you ensure that even if a password is compromised, it is only usable for a limited period of time.
2. Protect against unauthorized access: If a user is no longer authorized to access a system, their password should no longer grant them access. Setting password expiration ensures that old passwords are no longer valid and access can be restricted.
3. Compliance: Many regulatory frameworks, such as PCI-DSS and HIPAA, require password expiration as part of their security requirements. Failing to comply with these requirements can result in penalties and fines.
4. Encourage regular password changes: Setting password expiration encourages users to change their passwords on a regular basis. This helps to ensure that passwords are not reused, and that users are not relying on the same password for extended periods of time.

In summary, setting user password expiration is an important security measure that helps protect against unauthorized access, compliance requirements, and encourages regular password changes.

 

 

The chage command in Linux is used to manage user password expiration information. It allows you to view and modify the password aging information for a user account. Here is the option table for chage command:

OptionDescription

-d, --lastday DAYS	Set the number of days since January 1st, 1970 when the password was last changed.
-E, --expiredate DATE	Set the date or number of days since January 1st, 1970 on which the user's account will no longer be accessible.
-h, --help	Display help message and exit.
-I, --inactive INACTIVE	Set the number of days after a password has expired before the account is permanently disabled.
-l, --list	Display the current password aging information for a user account.
-m, --mindays MIN_DAYS	Set the minimum number of days required between password changes.
-M, --maxdays MAX_DAYS	Set the maximum number of days a password is valid.
-R, --root CHROOT_DIR	Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.
-W, --warndays WARN_DAYS	Set the number of days before a password is set to expire that a warning message is issued.

Here are a few simple examples of using chage:

• To display the password aging information for a user account:

chage -l username

 

• To set the maximum number of days a password is valid for a user account:

chage -M 90 username

 

• To set the date on which the user's account will no longer be accessible:

chage -E "2023-03-31" username

• To set the minimum number of days required between password changes:

chage -m 7 username