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
Is it still possible to add an extra key (in another slot) to unlock it with cryptsetup? Adding this extra key might beat the purpose of using the TPM but if you choose a long random key and store it in a password manager that should still be pretty safe right?
it’s not, because to to so you need to enter a valid passphrase to cryptsetup, which the recovery key is NOT