Linux Mint with Full Disk Encryption, directory /boot included
Part 1 - PC with firmware BIOS & HDD with MBR partitioning scheme
Author: Naldi Stefano (linux22 at Mint Forum)
June 2015

Version 2.4

Last update:  3 May 2017

 

Other tutorials concerning  Linux Mint with Full Disk Encryption, directory /boot included:

• LINUX MINT FDE FOR PC UEFI + HDD GPT, BOOTING WITH EFI STUB LOADER   New !!!
• LINUX MINT FDE FOR PC BIOS + HDD GPT
• LINUX MINT FDE FOR PC UEFI + HDD GPT
• HOW TO ENABLE UEFI SECURE BOOT WITH YOUR OWN CUSTOM KEYS
• DUAL BOOT FOR WINDOWS 10 & LINUX MINT FOR PC UEFI + HDD GPT

 

Table of contents

GNU Free Documentation License

GNU GENERAL PUBLIC LICENSE

Disclaimer and acknowledgments

Useful links

LINUX MINT FDE INSTALLATION FOR PC WITH BIOS AND HDD WITH MBR

Step 1 - Set up the target HDD, require Ubiquity

Step 2 - Set up the LVM, Physical Volume, Volume Group and Logical Volumes for root and  swap, require a few Terminal commands

Step 3 - Set up of the Linux installation, require Ubiquity

Step 4 - Fixing, patching and updating of the Linux installation made with Ubiquity, require a lot of Terminal commands

Appendix A – How to enhance the encryption strength of your Linux Mint FDE (for paranoids, like me)

Appendix B – Emergency tools - How to access your encrypted partition with your Mint or Ubuntu Live CD

Appendix C – Emergency tools - How to reinstall GRUB after ...

 

 

GNU Free Documentation License
Version 1.3, 3 November 2008

Linux Mint with Full Disk Encryption, directory /boot included - PC with BIOS and HDD with MBR

Copyright (C) 2015 2016 2017 2018 Naldi Stefano.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.

You should have received a copy of the "GNU Free Documentation License" along with this document.

If not, see <http://www.gnu.org/licenses/>.

 

 

GNU GENERAL PUBLIC LICENSE
Version 3, 29 June 2007

Linux Mint with Full Disk Encryption, directory /boot included - PC with BIOS and HDD with MBR

Copyright (C) 2015 2016 2017 2018 Naldi Stefano

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program 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 the GNU General Public License for more details.

You should have received a copy of the "GNU General Public License" along with this program.

If not, see <http://www.gnu.org/licenses/>.

 

 

Linux Mint 17.X and 18.X Full Disk Encryption (directory /boot included) - PC with firmware BIOS

I wrote this guide/tutorial with the hope that it will be useful for everyone who need a Linux installation with Full Disk Encryption. The solution here reported is EXPERIMENTAL and need a good experience with Linux and ts installation. At the moment I have successfully experimented this solution with Linux Mint 17.X and 18.X Cinnamon and Mate, Ubuntu 14.X, 15.X, 16.X and 17.X, all 64 bit version.
This guide/tutorial comes with ABSOLUTELY NO WARRANTY.

Prior of all I must thank Pavel Kogan (http://www.pavelkogan.com/2014/05/23/luks-full-disk-encryption/ and http://www.pavelkogan.com/2015/01/25/linux-mint-encryption/), because without his publications this solution would have never been possible.

Another thanks go to Rarylson Freitas (http://askubuntu.com/questions/468466/why-this-occurs-error-diskfilter-writes-are-not-supported), whose 00_header file patch has solved a fastidious warning during start-up.

Another thanks go to Callum Cameron, whose advices have showed me the correct installation of the system via Ubiquity (see the new structure of Step 1). That is an important achievement because now Ubiquity ends without errors, performing all the expected tasks. Callum has also build a script for the automatisation of the procedures described in this tutorial. If you want to try and test this script see the instructions at https://github.com/CallumCameron/mint-encrypted-install.

Other useful links are these:
 

• https://help.ubuntu.com/community/EncryptedFilesystemsViaUbiquity
• http://thesimplecomputer.info/full-disk-encryption-with-ubuntu
• https://wiki.archlinux.org/index.php/Dm-crypt/Encrypting_an_entire_system
• https://wiki.archlinux.org/index.php/Dm-crypt/Device_encryption#Keyfiles
• https://wiki.archlinux.org/index.php/Dm-crypt/System_configuration
• https://wiki.archlinux.org/index.php/GRUB#Boot_partition
• https://wiki.archlinux.org/index.php/LVM
• https://wiki.gentoo.org/wiki/GRUB2

The solution is essentially simple but require a lot of terminal commands. If the user make a mistake and commit a wrong command he can cancel the target HDD or damage its software structure. So, if you commit the commands listed in this guide/tutorial using 'Copy' and 'Paste' pay attention to do not alter them.

 

INSTALLATION FOR PC WITH BIOS AND HDD WITH MBR - BEGINNING

The installation require:

PC with firmware BIOS and HDD with MBR partitioning scheme.

HDD with at least 25 GB free space.

CD Live Mint 17.X, 18.X Cinnamon or Mate, or Ubuntu 14.X, 15.X, 16.X, 17.X

The installation here described assume:

Installation of Linux on: /dev/sda

Physical volume for encryption build on: /dev/sda1

Device for boot loader installation: /dev/sda

Physical Volume: /dev/mapper/sda1_crypt

Volume Group: mint

Logical Volume for swap: swap

Logical Volume for root: root

 

IF YOU CHANGE THESE ASSUMPTIONS THEN CHANGE THE UBIQUITY SETTINGS AND THE LISTED TERMINAL COMMANDS ACCORDINGLY !!!

MY ADVICE, BEFORE EXPERIMENTING THIS INSTALLATION ON A REAL PC, IS TO TRY AND INSTALL IT ON A VIRTUAL MACHINE LIKE VIRTUALBOX. WHEN THE USER SUCCEEDS WITH THE INSTALLATION AND BECOMES FAMILIAR WITH THE LISTED TERMINAL COMMANDS THEN HE CAN TRY A REAL INSTALLATION.
 

The procedure described in this guide/tutorial is divided in 4 steps and 3 appendix:


Step 1 – Set up the target HDD, require Ubiquity

Step 2 – Set up the LVM, Physical Volume, Volume Group and Logical Volumes for root and swap,
               require a few Terminal commands

Step 3 – Set up of the Linux installation, require Ubiquity

Step 4 – Fixing, patching and updating of the Linux installation made with Ubiquity, require a lot of
               Terminal commands

Appendix A – How to enhance the encryption strength of your Linux Mint FDE (for paranoids, like me)

Appendix B – Emergency tools - How to access your encrypted partition with your Mint or Ubuntu Live CD

Appendix C – Emergency tools - How to reinstall GRUB after ...

 

The Terminal commands listed in this guide/tutorial are typed in RED COLOR.


If you use 'Copy' and 'Paste' to insert these commands in your Terminal window, pay attention for those whose lenght takes two or more lines.
Prior to 'Paste' these long commands in Terminal check them inside an editor and if the command is broken in two or more lines reassemble it correctly over one single line. Then you can 'Paste' the command in your Terminal window.



Step 1

Boot your Live CD in the target PC and when ready open a Terminal windows, then start Ubiquity committing the following Terminal command:

 

In this way you can start Ubiquity skipping the installation of the boot loader and therefore finish the Ubiquity process without errors.

 

Click 'Continue'

 

If you are installing Linux Mint 18.X this new Ubiquity page will appear.

Here you can choose if installing third-party software or not.

Make your choice and go on.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Click 'Continue'

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Now you are in the 'Installation type' page. Select 'Something else' and click 'Continue'

 

Now you are in the “Partition manager” page. Check that your HDD is showed. Select the free space on your HDD and click '+'. You can see that the ComboBox 'Device for the boot loader installation' is not available. Please assume the same concept also for the next pictures. I will update them as soon as possible.

 

 

From the dropdown menu select the 'Type for the new partition' as 'Primary', 'Location for the new partition' as 'Beginning of this space' and 'Use as' as 'physical volume for encryption'. The system will ask for the security key (password) of the physical volume. Insert it twice. If you want to erase the empty disk space check the radio button below, but remember that it take a long time. Then click 'OK'.

 

 

After a few seconds you will see a new device named '/dev/mapper/sda1_crypt'.

Leave Ubiquity window open and go on.


Step 2

Open a Terminal window and commit the following 4 commands:
 

 

 

 

 

 

 

 

 

 

 

 

The first command create the Physical Volume, the second command create the Volume Group, the third command create the Logical Volumes for swap, with a size of 4 GB (the size is arbitrary), the fourth command create the Logical Volumes for root, with the remaining space available in the Volume group.

Leave the Terminal window open and go back to Ubiquity window and there click 'Back'.


Step 3
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

You are again in the 'Installation type' page of Ubiquity. Select 'Something else' and click 'Continue'

 

 

Now you are in the Partition manager page again. Check for the presence of the Logical Volumes named '/dev/mapper/mint-root' and '/dev/mapper/mint-swap'.

 

Select '/dev/mapper/mint-root', click 'Change' and select 'Use as' as 'Etx4 journaling file system' from the dropdown menu, then select 'Format the partition' and choose 'Mount point' as '/'. Then click 'OK'.

If you choose a different file system type (btrfs, JFS, XFS) pay attention for 'btrfs' file system. In this case see here for the correct 'btrfs' file system handling in Step 4.

 

 

Select '/dev/mapper/mint-swap', click 'Change' and select 'Use as' as 'swap area' from the dropdown menu, then click 'OK'. Then click 'Install Now'.

 

A popoup window named 'Write the changes to disks ?' will appear. Click 'Continue'.

 

Select your timezone and then click 'Continue'

Select your keyboard and then click 'Continue'

Choose your username and password and then click 'Continue'

 

Wait until Ubiquity show a popup like that ...

 

Click 'Continue Testing'. Ubiquity will ends.

 

Step 4

Now we have a Linux system build by Ubiquity that we must remount, fix, patch and update.

Go back to the Terminal window and commit the following 6 commands:

 

These commands mount the Linux system, previusly build by Ubiquity, in the directory /mnt.

If you have chosen a 'btrfs' type filesystem for your '/dev/mapper/mint-root' device you must substitute the first command

     sudo mount /dev/mapper/mint-root /mnt

with this new one

You will get a few warnings during GRUB installation but it seems working correctly anyway. If you need more detail about using 'btrfs' filesystem with LUKS/dm-crypt you can read the ArchLinux wiki at 'https://wiki.archlinux.org/index.php/Dm-crypt/Encrypting_an_entire_system#Btrfs_subvolumes_with_swap', paragraph 'Mount top-level subvolumes'.

-----

Now commit the following 4 commands:

 

The second command in this list of 4 will ask for the password of the encrypted volume. When the
script 'Enter any passphrase:' appear enter it.

These commands create a keyfile for automatic mounting of the encrypted volume when GRUB process ends. For more details see the articles of Pavel Kogan at http://www.pavelkogan.com.

-----

Now commit the following 2 commands:

 

These commands create the hook required by initramfs for the keyfile loading. For more details see the articles of Pavel Kogan at http://www.pavelkogan.com.

Otherwise you can create the hook file with sudo gedit /mnt/etc/initramfs-tools/hooks/crypto_keyfile and insert this line inside: cp /boot/crypto_keyfile.bin "${DESTDIR}"

-----

Now commit the following command:

 

This command update the crypttab file. For more details see the articles of Pavel Kogan at http://www.pavelkogan.com and the tutorial from the Ubuntu Official Documentation page at https://help.ubuntu.com/community/EncryptedFilesystemsViaUbiquity

-----

Now commit the following 2 commands:

 

These commands update the initramfs

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Now commit the following 3 commands:

 

These commands update the grub file. For more details see the articles of Pavel Kogan at http://www.pavelkogan.com.

Otherwise you can edit the grub file with sudo gedit /mnt/etc/default/grub and modify the directives inside in this way:

############################################################
GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_ENABLE_CRYPTODISK=y
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda1:sda1_crypt"
############################################################

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If you are installing Linux Mint 18.X or Ubuntu 16.X skip the following 4 commands !!!

Otherwise commit them.

These commands patch the 00_header file, fixing the handling of RAID and LVM volumes in GRUB.
You can omit these four command but when your system boot up it will show a message like that
"Error: diskfilter writes are not supported. Press any key to continue...". The system go fuhrter anyway but it is noisy. For more details see the article of  Rarylson Freitas  at http://askubuntu.com/questions/468466/why-this-occurs-error-diskfilter-writes-are-not-supported.

-----

Now commit the following 3 commands:

 

These commands update GRUB

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Now start the file browser Nemo (or Nautilus in Ubuntu) and search for a file named /mnt/sbin/initctl.REAL.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

If the file /mnt/sbin/initctl.REAL is present  you must rename /mnt/sbin/initctl  to  /mnt/sbin/initctl.orig and then rename /mnt/sbin/initctl.REAL  to  /mnt/sbin/initctl, committing the following 2 commands:

These commands rename the correct initctl file

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Now commit the last command:

 

This command umount the Linux system build by Ubiquity, now fixed, patched and updated.

-----------------------------------------------------------------------------------------------------------------------------
 

Now you can shut down the CD Live system and restart.

When your brand new Linux FDE start it will show a screen mask of GRUB like that.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Type your password for the encrypted volume and wait until the GRUB menu list appear (see hd0,msdos1).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wait until the countdown expires or type ENTER.

At this point, sometimes, the system remain frozen 1 or 2 minutes, wait until it go on.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Then the system will show the usual Mint logo and then the cryptsetup message.

 

 

 

 

 

 

 

 

 

 

 

 

 

When the login page appear insert you username and your password and ... enjoy.

 

INSTALLATION FOR PC WITH BIOS AND HDD WITH MBR - END

 

 

Appendix A

How to enhance the encryption strength of your Linux Mint FDE (for paranoids, like me)

 

You can see at the start of this tutorial that is Ubiquity who create the encrypted partition.

But you can enhance the strenght of you Linux Mint FDE creating the encrypted partition with the characteristics of your choice.

 

My first advice for a stronger encrypted installation is:

Boot your Live CD in the target PC and when ready ...

 

• Remeber that also this Appendix uses the same assumptions listed above
• Do not even start Ubiquity
• Skip Steps 1 and 2 of this tutorial

 

For HDD with MBR open a Terminal window and commit the following 8 commands:

The third command listed above will ask you for entering 'YES' (in uppercase) to continue; then remember to turn off the uppercase when it ask you for entering the password twice !!!

You can rise the '--iter-time' value of this third command but remember that it will slow down your system during the boot up !!!

A value of --iter-time 100000 take approx. 5 minutes for boot up on a PC with CPU i5 !!!

 

Now start Ubiquity with the Terminal command:

 

 

Select your language and Click 'Continue'

 

If you are installing Linux Mint 18.X this new Ubiquity page will appear.

Here you can choose if installing thirdy-part software or not.

Make your choice and go on.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Click 'Continue'

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When you reach the 'Installation type' page select 'Something else', click 'Continue' and then proceed with steps 3 and 4 of this tutorial until the end.

 

My second advice is:

Change the sixth command listed in Step 4 of this tutorial:

sudo dd bs=512 count=4 if=/dev/urandom of=/mnt/boot/crypto_keyfile.bin

with this new one

Warning: this command take a long long long time - approx. 30-40 minutes !!! on a PC with CPU i5, but only during the installation !!!

 

Anyway, also after these enhancements, you must not think that you are invulnerable.

You are vulnerable when you leave your system on and alone and when you are connected to a network or to internet.

 

And finally you must never forget that if your files are really interesting for the bad guys, the ugly truth is probably best depicted in this vignette:

 

I found this vignette on internet same years ago. Below you can see links to its repositories and its license.

https://xkcd.com/538/

http://www.explainxkcd.com/wiki/index.php/538:_Security

http://creativecommons.org/licenses/by-nc/2.5/

 

 

Appendix B

Emergency tools - How to access your encrypted partition with your Mint or Ubuntu Live CD
 

If your system does not start, because of PC hardware failure, boot-up files damage, ecc., but you are sure that your HDD (containing the encrypted partition) is OK you can access your data using the following procedure.

Start your PC with a Mint Live CD containing the same Linux Mint version installed in your HDD.

 

 

When your live system is up and running open a terminal window and commit the following 2 commands:

In this example we assume that your HDD reside on the installation PC and that you followed the installation procedure listed in this tutorial. Otherwise change the devices and LVM letter, number and names accordingly.

Remember that if you have chosen a 'btrfs' type filesystem for your '/dev/mapper/mint-root' device you must substitute the second command

     sudo mount /dev/mapper/mint-root /mnt

with this new one

    

Now your encrypted partition is mounted under the /mnt directory of your Linux Mint live system and you can recover, backup or copy all the files that you need.
 

 

 

Appendix C

Emergency tools - How to reinstall GRUB after ...

A few people who have installed my Linux Full Disk Encryption solutions have asked me how reinstall GRUB after a:

- GRUB package update/upgrade
- Boot up failure
- Booting files damage
- Linux Mint release upgrade
- Linux kernel release upgrade

They are right because this Linux FDE solution is EXPERIMENTAL and the GRUB configuration is made with an unusual and NOT STANDARD method.

The lacking of a recovery/emergency tool for these eventualities has reached a great importance once I have knew that many people are using this Linux FDE solution and they are upgrading their Linux version with the latest release or they are installing software packages that modifies GRUB and its configuration files.

So I have writed this simple appendix containing the correct procedure for the reinstallation of the original GRUB configuration for this Linux FDE solution.

The first step is reaching the access to your encrypted partition using the procedure listed in the Appendix B of this tutorial.

Once you have a Linux Mint or Ubuntu Live CD system up and running and your encrypted partition mounted under the "/mnt" directory you can proceeed with the reconfiguration of GRUB.

You must only repeat 15 Terminal commands yet listed in Step 4 of this tutorial:

The eighth ninth tenth and eleventh commands are necessary only in case of GRUB package update/upgrade and never if you are installing Linux Mint 18.X or Ubuntu 16.X !!!

Now your original Linux Mint FDE GRUB configuration have been reinstalled and you can restart your PC.

 

As my last consideration I want to say that I do not believe necessary rebuild also the '/mnt/etc/default/grub' file, because I think that a smart update/upgrade package for GRUB or Linux should not discard the modifications made by the user. Anyway if it will be necessary you must only edit your '/mnt/etc/default/grub' file and  rebuild the same modifications listed in Step 4 of this tutorial (remember only that you must do these modifications in the appropriate order, i.e. after you have committed the commands for the update of the initramfs).

 

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The topic for this tutorial at the Mint Forum is: https://forums.linuxmint.com/viewtopic.php?t=198077


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