Linux prohibits single-user mode (single) to enhance system security

Linux prohibits the single user mode (single) and enhances System Security-General Linux technology-Linux technology and application information. For more information, see the following. When the kernel is listed at boot, press any key to stop at the kernel selection. Press e on the kernel, press e on Red Hat Enterprise Linux, and add single to single user mode at the end of the kernel startup partition, in this way, we can get a password to access the system. It's so uncomfortable that someone else has logged on to the system and taken the file away.

Here we will introduce a method to add a password to grub to prohibit others from entering the system in single-user mode. 2 methods

1. in plaintext mode, add the following line in the splashimage parameter:

Password = password

2. MD5 encryption method. Add the following line in the splashimage parameter:

Password -- md5 MD5 ciphertext

For example:

Splashimage = (hd0, 0)/grub/splash.xpm.gz
Password -- md5 $1 $ xI6vS $ Wi5pi8JyORUNnj3/0Yq2/0
Hiddenmenu

Ciphertext in linux system with grub-md5-crypt to create, terminal input grub-md5-crypt press enter, then the system will require two identical password, then the system will output the MD5 code.

[Root @ localhost ~] # Grub-md5-crypt
Password:
Retype password:
$1 $ xI6vS $ Wi5pi8JyORUNnj3/0Yq2/0
[Root @ localhost ~] #

After saving it, restart the computer and log on to the GRUB menu page again. You cannot directly use the e command to edit the startup tag. You must use the p command first, enter the correct password to edit the startup tag.