From 7e550dc1b266c7fede3edc101bd49cdecfa4a5da Mon Sep 17 00:00:00 2001
From: n <n@tourmentine.com>
Date: Thu, 14 Mar 2019 17:18:30 +0100
Subject: [PATCH] pivotroot.sh to wipe a remote debian machine

---
 README.md    |  1 +
 pivotroot.sh | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100755 pivotroot.sh

diff --git a/README.md b/README.md
index 5c6c7c5..86e1d36 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ Scripts
   * [secupdate](https://forge.tourmentine.com/n/scripts/src/master/secupdate) => apply security updates & recompile kernel (FreeBSD)
   * [superscreen](https://forge.tourmentine.com/n/scripts/src/master/superscreen) => open multiple ssh sessions to a bunch of servers inside a screen
   * [zfsync.sh](https://forge.tourmentine.com/n/scripts/src/master/zfsync.sh) => sync some ZFS pools between two machines
+  * [pivotroot.sh](https://forge.tourmentine.com/n/scripts/src/master/pivotroot.sh) => pivot root to tmpfs on a live server in order to wipe it
 
 Greasemonkey/Userscripts
 ------------------------
diff --git a/pivotroot.sh b/pivotroot.sh
new file mode 100755
index 0000000..89d1946
--- /dev/null
+++ b/pivotroot.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+
+# script used to chroot/pivot a live system on tmpfs in order to wipe it
+# only tested with Debian 7.11
+#
+# first copy and execute it:
+# scp pivotroot.sh root@<remote_host>:/tmp/
+# ssh root@<remote_host> bash /tmp/pivotroot.sh
+#
+# you will then be able to connect again to it on port 666 (change it if you like) and do what you want
+#
+# note: bash is the default shell under debian so there will be bashisms (don't run it with Bourne shell)
+#
+
+apt-get install -y dropbear screen tmux
+
+CHROOTDIR='/tmp/tmproot'
+CHROOTPORT=666
+
+mkdir ${CHROOTDIR}
+mount -t tmpfs none ${CHROOTDIR}
+
+mkdir ${CHROOTDIR}/{bin,sbin,proc,sys,dev,run,usr,var,tmp,etc,root,oldroot}
+mkdir -p ${CHROOTDIR}/usr/bin
+mkdir -p ${CHROOTDIR}/lib/x86_64-linux-gnu ${CHROOTDIR}/lib64 ${CHROOTDIR}/usr/share ${CHROOTDIR}/usr/lib/x86_64-linux-gnu ${CHROOTDIR}/var/run/screen
+
+mount -t proc proc ${CHROOTDIR}/proc
+mount --bind /dev ${CHROOTDIR}/dev
+mount --bind /dev/pts ${CHROOTDIR}/dev/pts
+mount --make-rprivate / # necessary for pivot_root to work
+
+cp -vrp /usr/share/terminfo ${CHROOTDIR}/usr/share/
+cp -vrp /usr/lib/x86_64-linux-gnu/libevent* ${CHROOTDIR}/usr/lib/x86_64-linux-gnu/
+cp -vrp /lib/x86_64-linux-gnu/* ${CHROOTDIR}/lib/x86_64-linux-gnu/
+cp -vrp /lib64/ld-linux-x86-64.so.2 ${CHROOTDIR}/lib64/
+cp -vrp /sbin/* ${CHROOTDIR}/sbin/
+cp -vrp /bin/* ${CHROOTDIR}/bin/
+cp -vrp /usr/bin/id /usr/bin/shred /usr/bin/ldd /usr/bin/screen /usr/bin/tmux ${CHROOTDIR}/usr/bin/
+cp -vrp /usr/sbin/dropbear ${CHROOTDIR}/sbin/
+
+#cp -vrp /etc/passwd* /etc/shadow* /etc/group* /etc/shells ${CHROOTDIR}/etc/
+#cp -vrp /etc/dropbear ${CHROOTDIR}/etc/
+cp -vrp /etc/* ${CHROOTDIR}/etc/
+
+chmod g+w ${CHROOTDIR}/run 
+
+echo "" > ${CHROOTDIR}/root/.bash_history
+echo "TERM=xterm-16color" >>${CHROOTDIR}/root/.profile #necessary for tmux/screen to work
+echo "alias halt=\"echo 'o' > /proc/sysrq-trigger\"" >>${CHROOTDIR}/root/.profile 
+echo "alias reboot=\"echo 'b' > /proc/sysrq-trigger\"" >>${CHROOTDIR}/root/.profile 
+
+pivot_root ${CHROOTDIR} ${CHROOTDIR}/oldroot
+/sbin/dropbear -p ${CHROOTPORT}
+
+echo
+echo "system pivot-rooted."
+echo "you can now connect with ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p ${CHROOTPORT} root@`hostname`, launch screen/tmux and shred"
+echo "and finaly use reboot or halt commands (warning: they are not the real thing...)"
+echo
+echo "happy wiping!"
+echo