UEFI Secure Boot sign tool

The default signed Linux kernel on Ubuntu (>=16.04.x), Fedora and perhaps on other distributions as well, won't load unsigned external kernel modules if Secure Boot is enabled on UEFI systems. Hence, any external kernel modules like the proprietary Nvidia kernel driver, Oracle VM VirtualBox's host/guest kernel driver etc. won't work.

External kernel modules must be signed for UEFI Secure Boot using a Machine Owner Key (MOK). This is useful if you can't or don't wish to disable Secure Boot on your UEFI-enabled system.

UEFI Secure Boot Sign Tool can be used to sign kernel modules. Essentially, it is a wrapper around the sign-file binary in the kernel sources.

The systemd service can be enabled to automatically sign specific kernel modules with user's own once setup is complete.

Install and Setup

Fedora Dependencies:

• kernel-devel
• mokutil
• openssl
• Any text editor

Extract/Install the files in their respective locations. Download installation script from the releases page and run install.sh as root.

# ./install.sh

Generating a Public and Private X.509 Key Pair:

Generate a X.509 Key Pair as the UEFI Secure Boot Machine Owner Key.

$ openssl req -new -x509 -newkey rsa:2048 -keyout "/etc/sb-signtool/keyfiles/sb.priv" -outform DER -out "/etc/sb-signtool/keyfiles/sb_pub.der" -nodes -days 36500 -subj "/CN=<your name>/"

Import Public Key into UEFI-enabled System:

# mokutil --import "/etc/sb-signtool/sb_pub.der"

Edit the UEFI Secure Boot Sign Tool config file(s):

Must edit the following file before running script:

/etc/sb-signtool/modules.conf

You can check out an example file in the documentation.

Usage

Must run the Signing Tool every time a kernel module is rebuilt or when a new kernel is installed. Or enable the systemd service to do that on boot.

Run the UEFI Secure Boot Signing Tool:

# /usr/bin/sb-signtool-sign

Enable the systemd service:

# systemctl enable sb-signtool.service

TODO

• Packaging and distribution for Ubuntu, Fedora, Arch Linux etc.

Contributing and License

Feel free to create GitHub Issues and issue Pull Requests to contribute to this project.

Code released under GNU General Public License v2.0.