Shadow password hash explained

You can programmatically generate shadow password hash via:

$ openssl passwd -1 -salt G5cYam5w test.123

-1 means md5
G5cYam5w is a random salt (minimum 8)
test.123 is the password

Here is the breakdown:

The first $1 means that it is an md5 hash.
The second $G5cYam5w is a random salt.
The third $z0NDUjMRX4xVBKw9Nb6YL0 is the md5 hash.