#!/bin/sh -e
#    ecryptfs-verify
#    Copyright (C) 2011 Dustin Kirkland <kirkland@ubuntu.com>
#
#    Authors: Dustin Kirkland <kirkland@ubuntu.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; version 2 of the License.
#
#    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, see <http://www.gnu.org/licenses/>.

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

info() {
	echo `gettext "INFO:"` "$@"
}

usage() {
	echo "
Usage:
ecryptfs-verify [-h|--home] [-p|--private] [-e|--filenames-encrypted] [-n|--filenames-not-encrypted] [-u|--user USER] [--help]

 -h|--home			True if HOME is correctly configured for
				encryption, False otherwise

 -p|--private			True if a non-HOME directory is correctly
				configured for encryption, False otherwise

 -e|--filenames-encrypted	True if filenames are set for encryption,
				False otherwise

 -n|--filenames-not-encrypted	True if filenames are not encrypted,
				False otherwise

 -u|--user USER			By default, the current user's configuration
				is checked, override with this option

 --help 			This usage information

 Note that options are additive.  ALL checks must pass in order for this
 program to exit 0.  Any failing check will cause this program to exit
 non-zero.

"
	return 1
}

ecryptfs_exists() {
	local dotecryptfs="$1/.ecryptfs"
	if [ -d "$dotecryptfs" ]; then
		info "[$dotecryptfs] exists"
	else
		error "[$dotecryptfs] does not exist"
	fi
	return 0
}

sigfile_valid() {
	local sigfile="$1/.ecryptfs/Private.sig"
	if [ -f "$sigfile" ]; then
		info "[$sigfile] exists"
	else
		error "[$sigfile] does not exist"
	fi
	local c=$(wc -l "$sigfile" | awk '{print $1}')
	if [ "$c" = "1" ] || [ "$c" = "2" ]; then
		info "[$sigfile] contains [$c] signatures"
	else
		error "[$sigfile] does not contain exactly 1 or 2 lines"
	fi
	return 0
}

mountfile_valid() {
	local mountfile="$1/.ecryptfs/Private.mnt"
	if [ -f "$mountfile" ]; then
		info "[$mountfile] exists"
	else
		error "[$mountfile] does not exist"
	fi
	local m=$(cat "$mountfile")
	if [ -d "$m" ]; then
		info "[$m] is a directory"
	else
		error "[$m] is not a directory"
	fi
	return 0
}

automount_true() {
	local home="$1"
	local automount="$1/.ecryptfs/auto-mount"
	if [ -f "$automount" ]; then
		info "[$automount] Automount is set"
	else
		error "[$home/.ecryptfs/auto-mount] does not exist"
	fi
	return 0
}

owns_mountpoint() {
	local owner=$(stat -c "%U" "$2")
	if [ "$owner" = "$1" ]; then
		info "Ownership [$owner] of mount point [$2] is correct"
	else
		error "Invalid owner [$owner] of mount point [$2]"
	fi
}

mount_is_home() {
	local home="$1"
	local mountfile="$home/.ecryptfs/Private.mnt"
	local m=$(cat "$mountfile")
	if [ "$m" = "$home" ]; then
		info "Mount point [$m] is the user's home"
	else
		error "Mount point [$m] is not the user's home [$home]"
	fi
	owns_mountpoint "$user" "$m"
	return 0
}

mount_is_private() {
	local home="$1"
	local mountfile="$home/.ecryptfs/Private.mnt"
	local m=$(cat "$mountfile")
	if [ "$m" != "$home" ]; then
		info "Mount point [$m] is not the user's home [$home]"
	else
		error "Mount point [$m] is the user's home"
	fi
	if [ -d "$m" ]; then
		info "Mount point [$m] is a valid directory"
	else
		error "[$m] is not a valid mount point"
	fi
	owns_mountpoint "$user" "$m"
	return 0
}

filenames_encrypted() {
	local sigfile="$1/.ecryptfs/Private.sig"
	local c=$(wc -l "$sigfile" | awk '{print $1}')
	if [ "$c" = "2" ]; then
		info "Filenames are encrypted"
	else
		error "Filenames are not encrypted"
	fi
	return 0
}

filenames_not_encrypted() {
	local sigfile="$1/.ecryptfs/Private.sig"
	local c=$(wc -l "$sigfile" | awk '{print $1}')
	if [ "$c" = "1" ]; then
		info "Filenames are not encrypted"
	else
		error "Filenames are encrypted"
	fi
	return 0
}

home="$HOME"
user="$USER"
checks=
while [ ! -z "$1" ]; do
	case "$1" in
		-h|--home)
			checks="$checks check_home"
			shift
		;;
		-p|--private)
			checks="$checks check_private"
			shift
		;;
		-e|--filenames-encrypted)
			checks="$checks check_filenames_encrypted"
			shift
		;;
		-n|--filenames-not-encrypted)
			checks="$checks check_filenames_not_encrypted"
			shift
		;;
		--help)
			usage
		;;
		-u|--user)
			user="$2"
			home=$(getent passwd "$user" | awk -F: '{print $6}')
			if [ ! -d "$home" ]; then
				error "Invalid home directory [$home] of [$user]"
			fi
			shift 2
		;;
	esac
done

if [ -z "$checks" ]; then
	error "No checks given"
fi

for i in $checks; do
	case "$i" in
		check_home)
			ecryptfs_exists "$home"
			sigfile_valid "$home"
			mountfile_valid "$home"
			automount_true "$home"
			mount_is_home "$home"
		;;
		check_private)
			ecryptfs_exists "$home"
			sigfile_valid "$home"
			mountfile_valid "$home"
			mount_is_private "$home"
		;;
		check_filenames_encrypted)
			ecryptfs_exists "$home"
			sigfile_valid "$home"
			filenames_encrypted "$home"
		;;
		check_filenames_not_encrypted)
			ecryptfs_exists "$home"
			sigfile_valid "$home"
			filenames_not_encrypted "$home"
		;;
		*)
			error "Invalid check [$i]"
		;;
	esac
done

info "Configuration valid"
exit 0