Ubuntu 无法使用 dropbear 启动到 busybox 进行远程 LUKS 解密

Question 1

在对 Google 进行深入研究并反复尝试了无数次之后，我终于弄明白了这一点。

以下是我根据问题中概述的步骤所采取的步骤：

删除了问题中引用的博客文章中的脚本
在反复试验中，最终从博客文章中概述的第 6 步ifconfig eth0 0.0.0.0 down中删除了它usr/share/initramfs-tools/scripts/init-bottom/dropbear；我从未将其添加回去，但从来不需要它

修改并添加了以下脚本这个帖子：

# Comment lines in /usr/share/initramfs-tools/scripts/local-top/cryptroot as follows:
#
if [ -z "$cryptkeyscript" ]; then
cryptkey="Unlocking the disk $cryptsource ($crypttarget)\nEnter passphrase: "
#if [ -x /bin/plymouth ] && plymouth --ping; then
# cryptkeyscript="plymouth ask-for-password --prompt"
# cryptkey=$(echo -e "$cryptkey")
#else
cryptkeyscript="/lib/cryptsetup/askpass"
#fi
fi



# Add /usr/share/initramfs-tools/hooks/cryptroot_unlock and make executable
#
# Prompt to unlock LUKS encrypted root partition remotely
#
# See linked post for sources and acknowledgements
#
#!/bin/sh
PREREQ=""
prereqs()
{
echo "$PREREQ"
}
case $1 in
prereqs)
prereqs
exit 0
;;
esac
. /usr/share/initramfs-tools/hook-functions
#
# Begin real processing
#
SCRIPTNAME=unlock
# 1) Create script to unlock luks partitions
cat > ${DESTDIR}/bin/${SCRIPTNAME} << '__EOF'
#!/bin/sh
/lib/cryptsetup/askpass "Enter volume password: " > /lib/cryptsetup/passfifo
__EOF
chmod 700 ${DESTDIR}/bin/${SCRIPTNAME}
# 2) Enhance Message Of The Day (MOTD) with info how to unlock luks partition
cat >> ${DESTDIR}/etc/motd << '__EOF'
To unlock root-partition run "${SCRIPTNAME}"
__EOF



# Add /usr/share/initramfs-tools/scripts/local-bottom/dropbear_kill_clients and make executable
#
#
# Kills all DropBear client sessions if InitRAMFS is left
#
# See linked post for sources and acknowledgements
#
#!/bin/sh
PREREQ=""
prereqs()
{
echo "$PREREQ"
}
case $1 in
prereqs)
prereqs
exit 0
;;
esac
#
# Begin real processing
#
NAME=dropbear
PROG=/sbin/dropbear
# get all server pids that should be ignored
ignore=""
for server in `cat /var/run/${NAME}*.pid`
do
ignore="${ignore} ${server}"
done
# get all running pids and kill client connections
for pid in `pidof "${NAME}"`
do
# check if correct program, otherwise process next pid
grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" || {
continue
}
# check if pid should be ignored (servers)
skip=0
for server in ${ignore}
do
if [ "${pid}" == "${server}" ]
then
skip=1
break
fi
done
[ "${skip}" -ne 0 ] && continue
# kill process
echo "$0: Killing ${pid}..."
kill -KILL ${pid}
done

修改并添加这些脚本之后，dropbear 可以启动了，但是我的网络设备无法连接网络，所以仍然无法连接到服务器。

我最终通过使用发现ls /sys/class/net我的网络适配器没有被调用eth0；显然这是一个旧的符号，不再被最近的 Ubuntu 版本使用，而且由于我找到的所有帖子都很旧，甚至很古老，eth0所以我只找到了相关的参考。

因此，利用这些信息以及从其他来源找到的一些片段，我进行了initramfs.conf如下修改：

修改了DEVICE=部分/etc/initramfs-tools/initramfs.conf内容如下：

DEVICE=<name of network adapter discovered using ls /sys/class/net>
IP=<Static IP Address>::<Default Gateway>:<Subnet Mask>::<name of network adapter>:off

更新initramfs（sudo update-initramfs -u）

现在dropbear连接到网络，我可以连接到服务器并远程解锁。

Answer

在对 Google 进行深入研究并反复尝试了无数次之后，我终于弄明白了这一点。