/etc/shadow

25 Jul, 2023

/etc/shadow stores the actual hashed user passwords and the additional properties related to the password. The structure of the items in this file can be seen in the example below:
rangeforce:$6$3A6480HDa$3a011416c644336.e802RF433af:18075:0:99999:7:::

Username.
Password hash: Usually stored in the format $i d$ salt $h a s h, w h e r e t h e i d i d e n t i f i e s t h e h a s h i n g a l g o r i t h m :$ 1$ is MD5 $2$ is bcrypt $5$ is SHA-256 $6$ is SHA-512
Days since last password change in Unix time.
The minimum number of days required between password changes.
The maximum number of days the password is valid.
The number of days before password expiration that the user is warned that his/her password must be changed.