Procedure to password protect your grub menu is simple. Steps are mentioned below.
1. Use the command grub-md5-crypt to generate an encrypted password in MD5 (Message Digest Algorithm 5) format.
[root@localhost ~]# grub-md5-crypt
Password:
Retype password:
$1$POASwwdRoW$3.eaRn3fFinARCXjN9CRh/qG/
Password:
Retype password:
$1$POASwwdRoW$3.eaRn3fFinARCXjN9CRh/qG/
2. Open your /boot/grub/grub.conf file and copy the encrypted password.
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that
# all kernel and initrd paths are relative to /, eg.
# root (hd0,0)
# kernel /boot/vmlinuz-version ro root=/dev/sda1
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
password --md5 $1$POASwwdRoW$3.eaRn3fFinARCXjN9CRh/qG/
title Fedora (2.6.23.1-42.fc8)
root (hd0,0)
kernel /boot/vmlinuz-2.6.23.1-42.fc8 ro root=LABEL=/
initrd /boot/initrd-2.6.23.1-42.fc8.img
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that
# all kernel and initrd paths are relative to /, eg.
# root (hd0,0)
# kernel /boot/vmlinuz-version ro root=/dev/sda1
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
password --md5 $1$POASwwdRoW$3.eaRn3fFinARCXjN9CRh/qG/
title Fedora (2.6.23.1-42.fc8)
root (hd0,0)
kernel /boot/vmlinuz-2.6.23.1-42.fc8 ro root=LABEL=/
initrd /boot/initrd-2.6.23.1-42.fc8.img
Enter the password --md5 ENCRYPTED-PASSWORD line just before the title line.
3. Restart your computer and to modify the GRUB menu first enter p and then enter the password that you encrypted.
4. Now your GRUB is MD5 password protected.
