HOWTO: Unlock A LUKS Encrypted Root Partition Via SSH On Ubuntu

[peter7]

I am trying to apply the Howto indicated in the title to a fully encrypted (by alternative
install) Kubuntu 8.04. I can login over ssh after the boot but the
"unlock" command is just hanging there with the message:

Setting up cryptographic volume sda2_crypt (based on /dev/disk/by-uuid/...

It never prompts for the pass phrase or does anything.

I was wondering if anybody has some idea how to proceed. I tried to do
manually what unlock does with the same result.

[sjau]

you do have a fully encrypted system?

[peter7]

Yes I do, except the /boot partition of course.

[sjau]

Post your /etc/initramfs-tools/scripts/local-top/cryptroot script

[peter7]

Originally Posted by sjau

Post your /etc/initramfs-tools/scripts/local-top/cryptroot script

This directory is empty.

If you mean the file /scripts/local-top/cryptroot in the netboot initrd image then it is the same as what is in the original initrd. Which in turn comes from /usr/share/initramfs-tools/scripts/local-top/cryptroot unmodified. These files are part of the cryptsetup package and are the same over all ubuntu based distros. My cryptsetup is version 2:1.0.5-2ubuntu12

What I noticed that the prompt asking for the pass phrase showed up on the console instead of in my ssh session but took no input.

[sjau]

are you using LVM?

[peter7]

Originally Posted by sjau

are you using LVM?

Yes, but the encryption is on the underlying (single) physical partition.
The failed netboot procedure does not get to the lvm phase at all.

[sjau]

there has been an issue with kernel and lvm... I don't recall the exact specifics right now....

[sjau]

I just re-set it up according to my howto in a vm... it works great... the only problem I had (in the beginning) that I did copy a single/recovery user grub entry.... once I realized that it worked again...

So, try it on your computer in a vmware or so with a non-lvm install....