Installing Trisquel GNU/Linux with full disk encryption (including /boot)

Because GRUB is installed directly as a payload of libreboot (or coreboot), you don't need an unencrypted /boot partition when setting up an encrypted system. This means that your machine can really secure data while powered off.

This works in Trisquel 7, and probably Trisquel 6. Boot the 'net installer' (Install Trisquel in Text Mode). How to boot a GNU/Linux installer.

Set a strong user password (ideally above 40 characters, of lowercase/uppercase, numbers and symbols).

when the installer asks you to setup encryption (ecryptfs) for your home directory, select 'Yes' if you want to: LUKS is already secure and performs well. Having ecryptfs on top of it will add noticeable performance penalty, for little security gain in most use cases. This is therefore optional, and not recommended. Choose 'no'.

Your user password should be different than the LUKS password which you will set later on. Your LUKS password should, like the user password, be secure.

Partitioning

Choose 'Manual' partitioning:

Further partitioning

Now you are back at the main partitioning screen. You will simply set mountpoints and filesystems to use.

Kernel

Installation will ask what kernel you want to use. linux-generic is fine.

Tasksel

Just continue here, without selecting anything. You can install everything later (it's really easy).

Install the GRUB boot loader to the master boot record

Choose 'Yes'. It will fail, but don't worry. Then at the main menu, choose 'Continue without a bootloader'.

You do not need to install GRUB at all, since in libreboot you are using the GRUB payload (for libreboot) to boot your system directly.

Clock UTC

Just say 'Yes'.

Booting your system

At this point, you will have finished the installation. At your GRUB payload, press C to get to the command line.

Do that:
grub> cryptomount -a (ahci0,msdos1)
grub> set root='lvm/buzz-distro'
grub> linux /vmlinuz root=/dev/mapper/buzz-distro cryptdevice=/dev/mapper/buzz-distro:root
grub> initrd /initrd.img
grub> boot

ecryptfs

If you didn't encrypted your home directory, then you can safely ignore this section.

Immediately after logging in, do that:
$ sudo ecryptfs-unwrap-passphrase

This will be needed in the future if you ever need to recover your home directory from another system, so write it down and keep the note somewhere secret. Ideally, you should memorize it and then burn the note (or not even write it down, and memorize it still)>

Modify grub.cfg (CBFS)

Now you need to set it up so that the system will automatically boot, without having to type a bunch of commands.

Modify your grub.cfg (in the firmware) using this tutorial; just change the default menu entry 'Load Operating System' to say this inside:

cryptomount -a (ahci0,msdos1)
set root='lvm/buzz-distro'
linux /vmlinuz root=/dev/mapper/buzz-distro cryptdevice=/dev/mapper/buzz-distro:root
initrd /initrd.img

Additionally, you should set a GRUB password. This is not your LUKS password, but it's a password that you have to enter to see GRUB. This protects your system from an attacker simply booting a live USB and re-flashing your firmware. This should be different than your LUKS passphrase and user password.

The GRUB utility can be used like so:
$ grub-mkpasswd-pbkdf2

Give it a password (remember, it has to be secure) and it'll output something like:
grub.pbkdf2.sha512.10000.711F186347156BC105CD83A2ED7AF1EB971AA2B1EB2640172F34B0DEFFC97E654AF48E5F0C3B7622502B76458DA494270CC0EA6504411D676E6752FD1651E749.8DD11178EB8D1F633308FD8FCC64D0B243F949B9B99CCEADE2ECA11657A757D22025986B0FA116F1D5191E0A22677674C994EDBFADE62240E9D161688266A711

Put that in the grub.cfg (the one for CBFS inside the ROM) before the 'Load Operating System' menu entry like so (example):

set superusers="root"
password_pbkdf2 root grub.pbkdf2.sha512.10000.711F186347156BC105CD83A2ED7AF1EB971AA2B1EB2640172F34B0DEFFC97E654AF48E5F0C3B7622502B76458DA494270CC0EA6504411D676E6752FD1651E749.8DD11178EB8D1F633308FD8FCC64D0B243F949B9B99CCEADE2ECA11657A757D22025986B0FA116F1D5191E0A22677674C994EDBFADE62240E9D161688266A711
		

Obviously, replace it with the correct hash that you actually got for the password that you entered. Meaning, not the hash that you see above!

After this, you will have a modified ROM with the menu entry for cryptomount, and the entry before that for the GRUB password. Flash the modified ROM using this tutorial.

Update Trisquel

$ sudo apt-get update
$ sudo apt-get upgrade

Install a desktop (optional)

Installs the default desktop:
$ sudo apt-get install trisquel

It might ask for postfix configuration. I just choose 'No configuration'.

Next time you boot, it'll start lightdm and you can login. To start lightdm now, do:
$ sudo service lightdm start

Go back to the terminal (ctrl-alt-f1) and exit:
$ exit

Go back to lightdm (ctrl-alt-f7) and login.

Since you installed using net install and you only installed the base system, network-manager isn't controlling your eth0 but instead /etc/network/interfaces is. Comment out the eth0 lines in that file, and then do:
$ sudo /etc/init.d/networking stop
$ sudo service network-manager restart

Conclusion

If you followed all that correctly, you should now have a fully encrypted system.


Copyright © 2014 Francis Rowe <info@gluglug.org.uk>
This document is released under the Creative Commons Attribution-ShareAlike 4.0 International Public License and all future versions. A copy of the license can be found at ../license.txt.

This document is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See ../license.txt for more information.