/etc/shadow

• Historically, passwords appeared, in encrypted format, in the "/etc/passwd" file.
• However, since this file is world-readable (i.e. all Users on the system can and must be able to read it), this allowed various cracking attacks.
• Thus, passwords are now stored in the file "/etc/shadow", and only the "root" User may read this file.
• A line in this file is split into fields using the ':' character:
  • User Name
  • Password (in encrypted format).
  • Various dates, used for account management.

Originally written by guy keren