Warning: ubuntu tpm recovery key cannot unlock disk outside of boot
Hi everybody, bit of a warning here: The recovery key generated during the installation of Ubuntu 23.10 (if you select tpm-backed fde) cannot be used to unlock the disk outside of boot, as in any 'cryptsetup' command and so on will not accept the recovery key. unlocking when accessed from different system does not work etc.
You can use it to unlock the disk while booting if your tpm somehow fails, but ONLY in that specific situation.
I kind of purposefully broke my tpm keys to see if it could be restored with 23.10 and ended up having to reinstal, as I ended up having to enter the recovery key at boot every time and no way of adding additional unlock options to the volume, as cryptsetup would not accept the recovery key as passphrase.
This bug could be very bad for new users.
See this bug report: https://bugs.launchpad.net/ubuntu-desktop-installer/+bug/2039741
@Skull giver -- I mentioned this above, but couldn't link it to you.
I like the code but the
go run recover.go 2> key.textdoes not redirect the key to a file. It does not get input of the recovery key, so errors. Could you please add a few lines to write it directly to that file, instead of displaying it? (or output to both?)As someone thought, what is displayed onscreen is jibberish, because console cannot display raw hex characters... I'm thinking the LUKS key in the keyslot is raw or hex.
As I now know, it is translated. And we can get the recovery key (hopefully) translated the other way around...
If I can just find the valid key value, and write it to a file, then I can help @inchbinjasokreativ to write it back to his TPM. I've already written a BASH script to do that, but am just missing that key-file. I have the problem replicated to a VM, so can test it on that first.