Cryptsetup on Kenno's Open Note

Changing LUKS Passphrase

Sun, 12 Jul 2020 23:07:26 +1000

In my previous blog post, Managing File System Encryption with LUKS, I showed how to create an encrypted partition (of disk) using LUKS.

Today, I’d like to show you how we can change the passphrase on this LUKS encrypted partition and keeping this passphrase (key) in the same slot.

While I’m writing this blog post, I cannot remember how to do this, and I’m going to try to figure this out without doing the Google search. :)

Managing File System Encryption with LUKS

Sun, 28 Jun 2020 21:31:48 +1000

Last year, I already wrote a blog post about the same topic: Configure Encrypted Storage With LUKS, and I had used fdisk to create a disk partition. In this post, I’ll use parted to achieve the same thing.

I’m going to perform this operation on a server called servera on a disk device /dev/vdb.

First, let’s verify that vdb is available and has no partition:

[root@servera ~]# parted -l
...

Error: /dev/vdb: unrecognised disk label
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:

Use parted to create a partition on vdb using the whole disk.

Gentoo Luks Fails Kernel 5.6

Sat, 11 Apr 2020 01:05:06 +1000

My Gentoo based Linux laptop which is still running the older kernel 5.3.15. A short while back, I had a failed attempt to upgrade the kernel to 5.4.2 as the disk which encrypted with dm-crypt couldn’t be decrypted on boot. Since the older kernel 5.3.15 was working fine and free time was I what I lacked of, it seemed logical to just not doing anything about it.

Today while updating all the packages on my Gentoo laptop, I notice there was a newer kernel available: 5.6.3. So let’s try to install this newest kernel again and see if the issue with Luks/dm-crypt still persists.

Configure Encrypted Storage With LUKS

Thu, 29 Aug 2019 22:30:12 +1000

I’m currently preparing for the Red Hat Certified Specialist in Security: Linux exam (EX415). One of the exam objectives is about storage encryption using LUKS.

Here’s my note learning about LUKS. It’s not meant to be a guide which you should copy and paste and run it on your production system.

Suppose I have a new disk (/dev/vdb) attached to my server and I’d like to use it as an encrypted storage using LUKS. Here is how I’d do it.