From: James Bunton <jamesbunton@delx.net.au>
Date: Fri, 30 Oct 2015 23:57:59 +0000 (+1100)
Subject: reboot-no-passphrase for systems with LUKS encrypted root filesystems
X-Git-Url: https://code.delx.au/monosys/commitdiff_plain/1dab9607a5d0ce1cdd3fb02f04445fc38040f456

reboot-no-passphrase for systems with LUKS encrypted root filesystems
---

diff --git a/etc/systemd/system/disable-crypto_keyfile.service b/etc/systemd/system/disable-crypto_keyfile.service
new file mode 100644
index 0000000..7959532
--- /dev/null
+++ b/etc/systemd/system/disable-crypto_keyfile.service
@@ -0,0 +1,11 @@
+[Unit]
+Description=Disable /root/crypto_keyfile.bin on every boot
+After=basic.target
+
+[Service]
+Type=oneshot
+ExecStart=cryptsetup luksRemoveKey /dev/disk/by-uuid/%i /crypto_keyfile.bin
+SuccessExitStatus=2
+
+[Install]
+WantedBy=basic.target
diff --git a/scripts/reboot-no-passphrase b/scripts/reboot-no-passphrase
new file mode 100755
index 0000000..ebd8451
--- /dev/null
+++ b/scripts/reboot-no-passphrase
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# When using the Arch Linux mkinitcpio encrypt if the file /crypto_keyfile.bin
+# exists in the initramfs then it will be used to attempt unlocking.
+# 1. dd if=/dev/urandom of=/crypto_keyfile.bin bs=1 count=512
+# 2. mkinitcpio -p linux
+# 3. Add /crypto_keyfile.bin to FILES in /etc/mkinitcpio.conf
+# 4. Enable the disable-crypto_keyfiles@<root-disk-uuid>.service
+# 5. Run this script when you want to reboot without a passphrase
+
+
+crypto_keyfile="/crypto_keyfile.bin"
+
+if [ ! -f "$crypto_keyfile" ]; then
+    echo "Failed to find $crypto_keyfile"
+    exit 1
+fi
+
+disk_uuid="$(ls /etc/systemd/system/basic.target.wants/disable-crypto_keyfile@*.service | cut -d'@' -f2 | cut -d. -f1)"
+device_filename="/dev/disk/by-uuid/${disk_uuid}"
+if [ -z "$device_filename" ]; then
+    echo "Failed to find your encrypted device. You must have disable-crypto_keyfile@.service enabled."
+    exit 1
+fi
+
+set -x
+sudo cryptsetup luksAddKey "$device_filename" "$crypto_keyfile"
+sudo reboot