a script to initramfs that allows for keyfiles on USB drives to be used to unlock 22.04 disks

usb-unlock

#!/bin/sh
set -e

file="usbtries.txt"

if [ -e ${file} ]; then
    count=$(cat ${file})
else
    count=0
fi

count=$((count+1))

echo ${count} > ${file}

if [ "$count" -gt 3 ]; then
    /lib/cryptsetup/askpass "USB Unlock Key Not Found, Please enter your password: "
    exit;
fi

if [ ! -e /mnt ]; then
    mkdir -p /mnt
    sleep 3
fi

if mount /dev/disk/by-label/linux-key /mnt 2>/dev/null; then
    if [ -e /mnt/linux.key ]; then
        cat /mnt/linux.key
        exit
    fi
fi