Verify All Account Password Hashes are Shadowed

Description

If any password hashes are stored in /etc/passwd (in the second field, instead of an x or *), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.

Rationale

The hashes for all user account passwords should be stored in the file /etc/shadow and never in /etc/passwd, which is readable by all users.

PREVIEWING: may/unit-testing