Cryptsetup guide

cryptsetup-gui is a fairly simple application for unlocking and mounting LUKS paritions with a GUI. The intended use is for mounting an encrypted home partition after login, but it can be used for any encrypted partition. It is invoked with the name of an encrypted partition, looks up that name in /etc/crypttab to find the device, prompts the Setup the decrypted block device sudo cryptsetup open /dev/loop0 loop0 Format the decrypted block device sudo mkfs.ext4 /dev/mapper/loop0 Finally, mount it over your existing home directory sudo mount /dev/mapper/loop0 "/home/$ {USER}" The first time, you'll need to fix the permissions sudo chown "$ {USER}:$ {USER}" "/home/$ {USER}" Installation of cryptsetup. Install cryptsetup by running the following commands: ./configure --prefix=/usr --disable-ssh-token && make. To test the result, issue as the root user: make check. Some tests will fail if appropriate kernel configuration options are not set. cryptsetup luksFormat --type luks2 /dev/sda3 cryptsetup open /dev/sda3 cryptlvm. Instead of cryptlvm you can also use your own custom name, just make sure to replace every occurrence of cryptlvm in this tutorial with it. LVM setup. Let's create a new LVM inside the encrypted partition: Manually, by using the cryptsetup repair command on the LUKS2 device. 12.4. Encrypting existing data on a block device using LUKS2 This procedure encrypts existing data on a not yet encrypted device using the LUKS2 format. A new LUKS header is stored in the head of the device. Prerequisites The block device contains a file system. $ sudo cryptsetup luksOpen /path/to/encrypted/block/device dm-volume-name The volume name is exactly what we need to provide in the first column of each row in the crypttab file. The second column: the encrypted block device The second column of the crypttab file is used to reference the encrypted block device. On Ubuntu (Gnome) press the Show Applications button at lower-left corner In the subsequent text search field type " Term " until just the Terminal icon is shown Press the icon to launch Terminal. Instead of these steps you can just press Ctrl+Alt+T hot-key combination. Pre-Prepare Encrypted Partitions Boot the system Press and hold the Enter key Wait for about ninety seconds That's it. A Busybox shell will appear, giving the attacker the keys to your encrypted kingdom. How do you fix this? 2 Encrypting the device holding /boot There are two alternatives here: Either format an existing /boot partition to LUKS1; or Move /boot to the root file system. The root device (s) needs to use LUKS version 1, but existing LUKS2 devices can be converted (in-place) to LUKS1. These two alternatives are described in the two following sub-sections. Use LUKS1 ( cryptsetup luksFormat --type luks1) for partitions that GRUB will need to unlock. The LUKS2 format has a high RAM usage per design, defaulting to 1GB per encrypted mapper. Machines with low RAM and/or multiple LUKS2 partitions unlocked in parallel may error on boot. See the --pbkdf-memory option to control memory usage. [1] cryptsetup; cryptsetup; Wiki; DMCrypt; Last edited by Milan Broz Aug 20, 2020. Page history DMCrypt. Clone repository. ABI tracker index.html API index.html Cryptsetup wiki DMCrypt DMIntegrity DMVerity FrequentlyAskedQuestions Specification TKS1 TrueCryptOnDiskFormat Home The Cargo Guide cryptsetup-0.2.0. cryptsetup 0.2.0 Docs.rs crate page Apache-2.0 Links; Documentation Repository Crates.io Source Owners; pijul P-E-Meunier cryptsetup; crypt