[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 :)
Never apologize for enjoying the discovery of new things. That’s awesome, enjoy it.
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
Ideally you would never have to because you just have the two people come up with their part of the password and then initialise the LUKS partition together. Sorta like a key ceremony
Yeah, you’re right. That’s better.
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.
we really ain’t making any jokes on the name of the drives? okay…
Actually the bottomLuks generates most of the power.
Speed has everything to do with it.
Well considdering it was posted by a user with the username “communism” i will assume bottomLuks
Communism doesn’t have hierarchy tho
That’s very true.
But Marxist-Leninism (Lemmy.ml), the attempt to make communism practical and achievable and bumbling into fascism, does have a 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.
top / bottom
( ͡° ͜ʖ ͡°)
You can, sure, but you probably shouldn’t. Encrypting and decrypting consume additional cpu time, and you won’t gain much in terms of security.
not really if you have a hardware chip that does the encrypt/decrypting
