[Image description:
Screenshot of terminal output:
~ ❯ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 1 62.5M 0 disk
└─topLuks 254:2 0 60.5M 0 crypt
└─bottomLuks 254:3 0 44.5M 0 crypt
/end image description]
I had no idea!
If anyone else is curious, it’s pretty much what you would expect:
cryptsetup -y -v luksFormat /dev/sda
cryptsetup open /dev/sda topLuks
cryptsetup -y -v luksFormat /dev/mapper/topLuks
cryptsetup open /dev/mapper/topLuks bottomLuks
lsblk
Then you can make a filesystem and mount it:
mkfs.ext4 /dev/mapper/bottomLuks
mount /dev/mapper/bottomLuks ~/mnt/embeddedLuksTest
I’ve tested putting files on it and then unmounting & re-encrypting it, and the files are indeed still there upon decrypting and re-mounting.
Again, sorry if this is not news to anyone else, but I didn’t realise this was possible before, and thought it was very cool when I found it out. Sharing in case other people didn’t know and also find it cool :)
we really ain’t making any jokes on the name of the drives? okay…
Well considdering it was posted by a user with the username “communism” i will assume bottomLuks
Wouldn’t that be Anarchism/ Libertarian Socialism? Communism requires a state which is an implicit hierarchy.
Yeah, LUKS and most block level overlays just don’t care. That’s what good abstraction layers do for you!
You can LUKS on a disk image mounted over SSHFS that itself resides on a Ceph cluster and mounted over iSCSI for all it cares. Is it a block device? Yes? Good to go.
You can even LUKS a floppy if you want. Or a CD.
I remember years ago investigating alternatives to VMware vSAN and doing hyperconverged storage clusters in Red Hat with glusterFS in top of a couple of other layers. Feels rickety as heck putting it all together but it works well. Hard sell for “normal” people who expect to hit a Next button and get some pretty graphical chart though.
It would be good if you wanted to have a system that two people need to be present to unlock. Like those nuke launch locks that need two keys.
You can also just split the password for a single LUKS into two parts and give one each to the two people :D
But then you know both parts of the password and so must be killed to keep the machine secure
Tbf this would enforce the order in which the two people decrypt it, which may not be good if you expect these two people to “arrive” asyncrhonously and you don’t want them to have to wait for the other before entering their password/key. But maybe that’s too specific of a use case.
You’re a programmer, aren’t you? Always thinking about those race conditions and edge cases.
Definitely not professionally lol. I think I’d only want a programming job if I could somehow develop FOSS for a living, which is hard to get a full-time job in. And only to a limited extent as a hobby, though I do enjoy programming and am trying to teach myself more whenever I have the time :)
What about this: Top layer encrypted by Alice Middle layer encrypted by Bob Bottom layer encrypted by Alice
If Alice arrives first, she decrypts the top layer and has to wait for Bob to arrive. She cannot go because she has to decrypt the last layer. If Bob arrives first, he has to wait for Alice to arrive. He cannot go because he hasn’t decrypted anything yet.
Not really a solution but kind of helps.
That would just mean they both have to wait for each other rather than one having to wait for the other but not vice versa. Worse if you want to reduce the total amount of waiting, I guess better if you want there to be equality in having to wait for the other person lol
Never apologize for enjoying the discovery of new things. That’s awesome, enjoy it.
Now recursively create more layers until you have barely any free space left on the disk, then do some performance benchmarks. ;)
