vlock
vlock is a Virtual Console lock program.
Concepts
Sometimes a malicious local user could cause more problems than a sophisticated remote one. vlock is a program that locks one or more sessions on the Linux console to prevent attackers from gaining physical access to the machine.
Installation
USE flags
USE flags for app-misc/vlock Allows to lock one or all of the sessions of your console display
pam
|
Add support for PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip |
selinux
|
!!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur |
test
|
Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently) |
Emerge
To install app-misc/vlock:
root #emerge --ask app-misc/vlockUsage
When not working in a virtual console, switch to one by pressing CTRL+ALT+F1 through F6. By default, vlock locks the current console session. Use the -a switch in order to lock all console sessions.
user $vlock -aIt is also possible to use vlock from an X session. Use the -n option to make vlock switch to an empty virtual console.
root #usermod -a -G vlock larryuser $vlock -naDisable SysRq key
The magic SysRq key combination can unlock consoles when least expected. In order to prevent this, disable the SysRq mechanism while consoles are locked like so:
user $vlock -saIf a user does not know how to use the SysRq key, then it is probably not needed. Disable it when configuring the kernel:
Kernel hacking --->
[ ] Magic SysRq key