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GRUB & BIOS Password LINK

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GRUB Password Creation

This enables putting a password for accessing GRUB

1. Generate a GRUB Password Hash

First, create an encrypted password hash. Open your terminal and run:

grub2-mkpasswd-pbkdf2

Enter your desired password twice. The command will output a long hash string that looks like grub.pbkdf2.sha512.10000.E2.... Copy this entire string.

2. Set the Superuser and Password

Next, you need to add a configuration file to tell GRUB to use this password. The safest method is to create a new file in /etc/grub.d/ to avoid your changes being overwritten by system updates.

sudo nano /etc/grub.d/01_users

Paste the following content into the file. Replace admin with your desired username and paste the hash you copied in the previous step.

# Set a superuser and password for GRUB
cat << EOF
set superusers="admin"
password_pbkdf2 admin YOUR_COPIED_PASSWORD_HASH_HERE
EOF

Save the file and exit the editor (in nano, press Ctrl+X, then Y, then Enter).

Make the script executable:

sudo chmod +x /etc/grub.d/01_users

3. Update the GRUB Configuration

Finally, apply the changes to your GRUB configuration. The command differs based on your Linux distribution family.

  • On Debian/Ubuntu:
sudo update-grub
  • On Fedora/RHEL/CentOS:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

To protect menu entries, add this after each menuentry in /etc/grub.d/10_linux or similar:

--unrestricted  # if you want a specific entry to stay open

Or remove --unrestricted if you want password protection for that entry

You can remove it from the /etc/grub.d/10_linux file from the line starting with “CLASS”

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