[CentOS] Multiple grub2 Users with Passwords

Sun Nov 11 21:34:29 UTC 2018
Dr. Zenzic <dr.zenzic at gmail.com>

Hello All,

I am trying to set multiple users with passwords for modifying grub2
menu entries at boot. I know I can set a "root" user grub2 password with
grub2-setpassword. I have also been able to make a grub2 user password
using the grub2-mkpasswd-pbkdf2 command and adding

    set superusers="user1"

to the /etc/grub.d/40_custom file. However, I have multiple user
administrators that will possibly need access to grub at boot (i.e. to
boot to single user mode to fix a broken configuration file). I've tried
generating two different passwords with grub2-mkpasswd-pbkdf2 and adding:

    set superusers="user1, user2"

    password_pbkdf2 user1 grub.pbkdf2.sha512.1000./hash1/

    password_pbkdf2 user2 grub.pbkdf2.sha512.1000./hash2/

with no success. The first user account worked but not the second.

Does anyone know the correct syntax to add multiple grub2 user accounts
with different passwords in 40_custom? All tutorials I've found online
explain a single user but not multiple.