dropbear-initramfs can't find modprobe and blkid

Question

I'm trying to have dropbear remote ssh boot on a debian system which is encrypted with lvm crypto luks.

I can get it work on my raspberry pi but not on my regular system

steps: 1 install debian with encrypted LVM

ls -l /lib/modules/ |awk -F" " '{print $9}'
mkinitramfs -o /boot/initramfs.gz
echo initramfs initramfs.gz >> /boot/config.txt

then create an rsa ssh key with the following line in front and save it to /etc/dropbear-initramfs/authorized_keys: command="/scripts/local-top/cryptroot && kill -9 `ps | grep -m 1 'cryptroot' | cut -d ' ' -f 3`" ssh...

then:

mkinitramfs -o /boot/initramfs.gz 
reboot

i can type the password and decrypt with a keyboard but when i login with ssh I get :

/scripts/local-top/cryptroot: line 218: modprobe: not found
/scripts/local-top/cryptroot: line 378: blkid: not found
/scripts/local-top/cryptroot: line 378: blkid: not found
/scripts/local-top/cryptroot: line 378: blkid: not found
/scripts/local-top/cryptroot: line 378: blkid: not found
/scripts/local-top/cryptroot: line 378: blkid: not found
...

please help?

extra info:
my blkid

/dev/sda1: UUID="42a9ca50-b757-4e11-985f-8fc75323b598" TYPE="ext2" PARTUUID="38de37f0-01"
/dev/sda5: UUID="3448b157-a1f9-4f6a-a1ea-37e6362cdea8" TYPE="crypto_LUKS" PARTUUID="38de37f0-05"       
/dev/mapper/sda5_crypt: UUID="nzAaP7-Ocx9-BJzO-BM7S-SQcY-BHqp-tbgvH6" TYPE="LVM2_member"
/dev/mapper/deb--vg-root: UUID="f8ec5b07-75fe-4870-9fb6-9e9035d21a20" TYPE="ext4"               
/dev/mapper/deb--vg-swap_1: UUID="ff915ae6-210f-4bbb-8988-b30aacae3dea" TYPE="swap"

my /etc/fstab

/dev/sda1: UUID="42a9ca50-b757-4e11-985f-8fc75323b598" TYPE="ext2" PARTUUID="38de37f0-01"
/dev/sda5: UUID="3448b157-v4a5-4f6a-a1ea-28e6362cdea9" TYPE="crypto_LUKS" PARTUUID="38de37f0-05"
/dev/sdb1: UUID="CC55-BAFE" TYPE="vfat" PARTUUID="0000370e-01"                                          /dev/mapper/sda5_crypt: UUID="nzAaP7-Ocx9-BJzO-BM7S-SQcY-BHqp-tbgvH6" TYPE="LVM2_member"
/dev/mapper/theproject1--vg-root: UUID="f8ec5b07-75fe-4870-9fb6-9e9035d21a20" TYPE="ext4"
/dev/mapper/theproject1--vg-swap_1: UUID="ff915ae6-210f-4bbb-8988-b30aacae3dea" TYPE="swap"

my /etc/crypttab

sda5_crypt UUID=3448b157-v4a5-4f6a-a1ea-28e6362cdea9 none luks,discard

score 1 · Answer 1 · answered Oct 19 '19 at 14:46

I had a similar issue, but different resolution.

I have a encrypted Kali Linux computer and use the dropbear-initramfs package to unlock the root disk at boot remotely over the dropbear ssh session using cryptroot-unlock.

This worked fine for a long time, but after some update it stopped working. I could SSH to the initramfs disk dropbear session but when I did "cryptroot-unlock" it would hang and I would get the error "Error: Timeout reached while waiting for askpass."

Eventually I found the solution:- https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1687842.html Basically to fix I uninstalled "cryptsetup-nuke-password" package "apt remove cryptsetup-nuke-password". Then rebooted and then I could successfully open the encrypted /root partition remotely via the dropbear-initramfs.

If you are getting the error "Error: Timeout reached while waiting for askpass." when ssh'ed to your dropbear-initramfs at boot, trying to cryptroot-unlock the drive. To confirm if the issue is the same as mine then do a "ps" and look through the processes running. If see something similar to "/lib/cryptsetup/askpass.cryptsetup Please unlock disk .." then I suggest logging on via the console and removing "cryptsetup-nuke-password", to resolve the issue.

i'll try it right away, but might not be useful if you wanna have nuk keys on your drive. hope the developers are on it to fix the problem asap — soroush, Oct 20 '19 at 15:05

dropbear-initramfs can't find modprobe and blkid

1 Answers1