Can't get it to work with Ubuntu 20.04

[rrthomas]

I just upgraded to Ubuntu 20.04. I found that once again I am prompted for my passphrase on booting.

I re-did the installation process, which worked without error, and checked all the configuration items, none of which had changed.

I don't get any error on boot, but I have to enter my passphrase.

I had a look at /var/log/boot.log, and I can't see any messages written by /etc/decryptkeydevice/decryptkeydevice.sh.

The prompt I get for my passphrase is the normal one; I don't get the message FAILED to find suitable Key device from decryptkeydevice.sh, which suggests that it is not being run.

I checked the driver required for my key device, sdhci, and added it to modules.

As far as I can tell, the bug which this setup was created to work around has not been fixed.

Any ideas?

[stesee]

I had no time to look into Ubuntu 20.04 + automated unlocking until now. Have you seen https://unix.stackexchange.com/questions/582594/systemd-how-to-load-luks-passphrase-from-usb-falling-back-to-keyboard ? Sounds promising that it can be done. I plan to look into their solution and update my repo after testing it.

[rrthomas]

I hadn't found that question/answer; thanks very much! I'll take a look.

[rrthomas]

That worked fine in the end; it's simpler than your current system, requiring only a patched /usr/share/initramfs-tools/local-top/cryptroot, and a keyfile, and the only configuration items are the encrypted device name and the place to store the keyfile. The only obvious difference is that the keyfile is assumed to be a series of lines, and needs to be substituted into a shell script, so a randomly-generated key must not contain newline, quote, or other characters that could have meaning in a shell script. Probably easier, therefore, to base64-encode the output of the random source, or something similar.