#!/bin/sh
# -*- sh-basic-offset: 4; sh-indentation: 4; tab-width: 4; indent-tabs-mode: t; sh-indent-comment: t; -*-
# This script encrypts an user's home
#
# Written by Yan Li <yan.i.li@intel.com>, <yanli@gnome.org>
# Copyright (C) 2010 Intel Corporation
#
# Modified by Dustin Kirkland <kirkland@canonical.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.

set -e

PRIVATE_DIR="Private"

usage() {
       echo "
Usage:

$0 -u USER

 -u,--user       Migrate USER's home directory to an encrypted home directory

WARNING: Make a complete backup copy of the non-encrypted data to
another system or external media. This script is dangerous and, in
case of an error, could result in data lost, or lock you out of your
system!

This program must be executed by root.

"
	exit 1
}

error() {
	echo "$(gettext 'ERROR: ')" "$@" 1>&2
	exit 1
}

warning() {
	echo "$(gettext 'WARNING: ')" "$@" 1>&2
}

info() {
	echo "$(gettext 'INFO: ')" "$@" 1>&2
}

assert_dir_empty() {
	local DIR="$1"
	if [ -e "$DIR" ]; then
		# if $DIR is a directory, make sure it's empty
		if [ -d "$DIR" ]; then
			ls=$(ls -A "$DIR" | wc -l)
			if [ "$ls" != "0" ]; then
				echo 1>&2 "If you already have some data in directory $DIR,"
				echo 1>&2 "please move all of these files and directories out of the way, and"
				echo 1>&2 "follow the instructions in:"
				echo 1>&2 "    ecryptfs-setup-private --undo"
				echo 1>&2 
				error "$DIR is not empty, cannot continue."
			fi
		else
			error "$DIR exists but is not an empty directory, cannot continue."
		fi
	fi
}

# get user home by username
get_user_home () {
	local USER_NAME="$1"
	local USER_HOME=$(getent passwd $USER_NAME | cut -d":" -f 6)
	if [ -z "$USER_HOME" ]; then
		error "Cannot find the home directory of $USER_NAME."
	fi
	echo "$USER_HOME"
}

sanity_check () {
	local USER_NAME="$1"
	local USER_HOME="$2"
	if [ -e "$USER_HOME/.ecryptfs" ]; then
		error "$USER_HOME appears to be encrypted already."
	fi
	# Check for rsync
	if ! which rsync >/dev/null 2>&1; then
		error "Please install the rsync package."
	fi
	# Check free space: make sure we have sufficient disk space
	# available. To make a full copy, we will need at least 2.5x the
	# disk usage of the target home directory.
	info "Checking disk space, this may take a few moments.  Please be patient."
	needed=$(du -s "$USER_HOME" | awk '{printf "%.0f", $1*2.5}')
	free=$(df -P "$USER_HOME" | tail -n 1 | awk '{print $4}')
	if [ $needed -gt $free ]; then
		info "2.5x the size your current home directory is required to perform a migration."
		info "Once the migration succeeds, you may recover most of this space by deleting the cleartext directory."
		error "Not enough free disk space."
	fi
	assert_dir_empty "$USER_HOME/.$PRIVATE_DIR"
	assert_dir_empty "$USER_HOME/.ecryptfs"
	assert_dir_empty "/home/.ecryptfs/$USER_NAME"
}

encrypt_dir () {
	local USER_NAME="$1"
	local USER_HOME="$2"
	if ! which lsof >/dev/null 2>&1; then
		info "Please install lsof."
		error "Can not tell whether $USER_HOME is in use or not."
	fi
	info "Checking for open files in $USER_HOME"
	lsof=$(lsof +D "$USER_HOME" | wc -l)
	if [ "$lsof" != "0" ]; then
		info "The following files are in use:"
		echo
		lsof +D "$USER_HOME" | sed "s/^/    /"
		echo
		error "Cannot proceed."
	fi
	# start encryption
	orig=$(mktemp /home/$USER_NAME.XXXXXXXX)
	rm "$orig" && mv "$USER_HOME" "$orig"
	chmod 700 "$orig"
	mkdir -p -m 700 "$USER_HOME"
	USER_GROUP=$(id -g "$USER_NAME")
	chown "$USER_NAME:$USER_GROUP" "$USER_HOME" "$orig"
	ECRYPTFS_SETUP_PRIVATE_ARGS=""
	if [ -n "$LOGINPASS" ]; then
		ECRYPTFS_SETUP_PRIVATE_ARGS="-l $LOGINPASS"
	fi
	if [ -n "$MOUNTPASS" ]; then
		ECRYPTFS_SETUP_PRIVATE_ARGS="$ECRYPTFS_SETUP_PRIVATE_ARGS -m $MOUNTPASS"
	fi
	if ! ecryptfs-setup-private -u "$USER_NAME" -b $ECRYPTFS_SETUP_PRIVATE_ARGS; then
		# too bad, something went wrong, we'll try to recover
		rm -rf "$USER_HOME"
		mv "$orig" "$USER_HOME"
		exit 1
	fi
	info "Encrypted home has been set up, encrypting files now...this may take a while."
	rsync -a "$orig/" "$USER_HOME/"
	umount "$USER_HOME/"
	echo
	echo "========================================================================"
	echo "Some Important Notes!"
	echo
	echo " 1. The file encryption appears to have completed successfully, however,"
	echo "    $USER_NAME MUST LOGIN IMMEDIATELY, _BEFORE_THE_NEXT_REBOOT_,"
	echo "    TO COMPLETE THE MIGRATION!!!"
	echo
	echo " 2. If $USER_NAME can log in and read and write their files, then the migration is complete,"
	echo "    and you should remove $orig."
	echo "    Otherwise, restore $orig back to $USER_HOME."
	echo
	echo " 3. $USER_NAME should also run 'ecryptfs-unwrap-passphrase' and record"
	echo "    their randomly generated mount passphrase as soon as possible."
	echo
	echo " 4. To ensure the integrity of all encrypted data on this system, you"
	echo "    should also encrypted swap space with 'ecryptfs-setup-swap'."
	echo "========================================================================"
	echo
}

DO_ENCRYPT=
while true; do
	[ -z "$1" ] && break
	case "$1" in
		-u|--user)
			DO_ENCRYPT=1
			USER_NAME="$2"
			shift 2
		;;
		*)
			usage
		;;
	esac
done

if [ "$DO_ENCRYPT" != "1" ]; then
	usage
fi

if [ "$(id -u)" != "0" ]; then
	error "This program must be executed with root privileges"
fi

if [ "$DO_ENCRYPT" = "1" ]; then
	USER_HOME=$(get_user_home "$USER_NAME")
	sanity_check "$USER_NAME" "$USER_HOME"
	encrypt_dir "$USER_NAME" "$USER_HOME" "$LOGINPASS" "$MOUNTPASS"
fi