問題文
An auditor asks why the file that lists the accounts on a host is readable by everyone, and whether that exposes the passwords. The administrator explains that the encrypted passwords live elsewhere. Which arrangement is being described?
選択肢
- The account list holds names, numeric identifiers and the login shell, while a separate file that regular users cannot read holds the encrypted passwords and the aging information.
- Both files are readable by everyone, but the passwords are stored in a form that cannot be reversed, which is why exposing the file causes no risk at all.
- There is only one file and it is readable only by the administrator, and it is why ordinary programs ask a service for the mapping.
- The passwords are held in the account list but are hidden from users whose numeric identifier is above a threshold set at install time.