Changing Passwords in Linux

Basic Command for Changing Password

• To change a password in Linux, use the passwd or password command.

Storage of Passwords

• When a password is set, it is:
  • Securely scrambled.
  • Stored in a special privileged file: /etc/shadow.
  • This file is readable only by root to prevent unauthorized access.
  • Even with access, passwords cannot be de-scrambled from this file.

Forcing Password Change for Users

• To force a standard user to change their password:
  • Use the -e or --expire flag with the passwd command.
  • This action will immediately expire a user's password.
  • The user will be required to set a new password on their next login.