#!/usr/bin/env python
#
# Copyright (c) 2003-2007 Andrea Luzzardi <scox@sig11.org>
#
# This file is part of the pam_usb project. pam_usb is free software;
# you can redistribute it and/or modify it under the terms of the GNU General
# Public License version 2, as published by the Free Software Foundation.
#
# pam_usb 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


import dbus
import sys
import os
from xml.dom import minidom

class Device:
	def __init__(self, udi):
		self.__udi = udi
		self.__findStorageDevice()
		deviceObj = bus.get_object('org.freedesktop.Hal',
				udi)
		deviceProperties = deviceObj.GetAllProperties(
				dbus_interface = 'org.freedesktop.Hal.Device')
		self.vendor = deviceProperties['usb_device.vendor']
		self.product = deviceProperties['info.product']
		self.serialNumber = deviceProperties['usb_device.serial']

	def __isChildOfDevice(self, udi):
		obj = bus.get_object('org.freedesktop.Hal', udi)
		properties = obj.GetAllProperties(
				dbus_interface = 'org.freedesktop.Hal.Device')
		if not properties.has_key('info.parent'):
			return False
		if properties.has_key('info.bus') and properties['info.bus'] == 'usb_device':
			return False
		if properties['info.parent'] == self.__udi:
			return True
		return self.__isChildOfDevice(properties['info.parent'])

	def __findStorageDevice(self):
		for child in halManager.FindDeviceByCapability('storage'):
			if self.__isChildOfDevice(child):
				self.__storageUdi = child
				return
		raise Exception, '%s is not a storage device.' % self.__udi

	def __repr__(self):
		return "%s %s (%s)" % (self.vendor, self.product, self.serialNumber)

	def volumes(self):
		vols = []
		for volume in halManager.FindDeviceByCapability('volume'):
			deviceObj = bus.get_object('org.freedesktop.Hal',
					volume)
			deviceProperties = deviceObj.GetAllProperties(
					dbus_interface = 'org.freedesktop.Hal.Device')
			if deviceProperties['block.storage_device'] != self.__storageUdi:
				continue
			vols.append({'uuid' : deviceProperties['volume.uuid'],
				'device' : deviceProperties['block.device']})
			return vols

def listOptions(question, options, autodetect = True):
	if autodetect == True and len(options) == 1:
		print question
		print "* Using \"%s\" (only option)" % options[0]
		print
		return 0

	while True:
		try:
			print question
			for i in range(len(options)):
				print "%d) %s" % (i, options[i])
			print
			sys.stdout.write('[%s-%s]: ' % (0, len(options) - 1))
			optionId = int(sys.stdin.readline())
			print
			if optionId not in range(len(options)):
				raise Exception
			return optionId
		except KeyboardInterrupt: sys.exit()
		except Exception: pass
		else: break

def writeConf(options, doc):
	try:
		f = open(options['configFile'], 'w')
		doc.writexml(f)
		f.close()
	except Exception, err:
		print 'Unable to save %s: %s' % (options['configFile'], err)
		sys.exit(1)
	else:
		print 'Done.'

def shouldSave(options, items):
	print "\n".join(["%s\t\t: %s" % item for item in items])
	print
	print 'Save to %s ?' % options['configFile']
	sys.stdout.write('[Y/n] ')
	response = sys.stdin.readline().strip()
	if len(response) > 0 and response.lower() != 'y':
		sys.exit(1)

def prettifyElement(element):
	tmp = minidom.parseString(element.toprettyxml())
	return tmp.lastChild

def addUser(options):
	try:
		doc = minidom.parse(options['configFile'])
	except Exception, err:
		print 'Unable to read %s: %s' % (options['configFile'], err)
		sys.exit(1)
	devSection = doc.getElementsByTagName('devices')
	if len(devSection) == 0:
		print 'Malformed configuration file: No <devices> section found.'
		sys.exit(1)
	devicesObj = devSection[0].getElementsByTagName('device')
	if len(devicesObj) == 0:
		print 'No devices found.'
		print 'You must add a device (--add-device) before adding users'
		sys.exit(1)

	devices = []
	for device in devicesObj:
		devices.append(device.getAttribute('id'))
	device = devices[listOptions("Which device would you like to use for authentication ?",
		devices)]

	shouldSave(options, [
		('User', options['userName']),
		('Device', device)
		])

	users = doc.getElementsByTagName('users')
	user = doc.createElement('user')
	user.attributes['id'] = options['userName']
	e = doc.createElement('device')
	t = doc.createTextNode(device)
	e.appendChild(t)
	user.appendChild(e)
	users[0].appendChild(prettifyElement(user))
	writeConf(options, doc)

def addDevice(options):
	devices = []

	for udi in halManager.FindDeviceStringMatch('info.bus', 'usb_device'):
		try:
			devices.append(Device(udi))
		except Exception, ex:
			pass

	if len(devices) == 0:
		print 'No devices detected.'
		sys.exit()
	device = devices[listOptions("Please select the device you wish to add.", devices)]

	volumes = device.volumes()
	volume = volumes[listOptions("Which volume would you like to use for " \
			"storing data ?",
			["%s (UUID: %s)" % (volume['device'],
				volume['uuid'] or "<UNDEFINED>")
				for volume in volumes]
			)]

	if volume['uuid'] == '':
		print 'WARNING: No UUID detected for device %s. One time pads will be disabled.' % volume['device']

	shouldSave(options,[
		('Name', options['deviceName']),
		('Vendor', device.vendor),
		('Model', device.product),
		('Serial', device.serialNumber),
		('UUID', volume['uuid'] or "<UNDEFINED>")
		])

	try:
		doc = minidom.parse(options['configFile'])
	except Exception, err:
		print 'Unable to read %s: %s' % (options['configFile'], err)
		sys.exit(1)

	devs = doc.getElementsByTagName('devices')
	dev = doc.createElement('device')
	dev.attributes['id'] = options['deviceName']

	for name, value in (('vendor', device.vendor),
			('model', device.product),
			('serial', device.serialNumber),
			('volume_uuid', volume['uuid'])):
		if value == '':
			continue
		e = doc.createElement(name)
		t = doc.createTextNode(value)
		e.appendChild(t)
		dev.appendChild(e)

	# Disable one time pads if there's no device UUID
	if volume['uuid'] == '':
		e = doc.createElement('option')
		e.setAttribute('name', 'one_time_pad')
		e.appendChild(doc.createTextNode('false'))
		dev.appendChild(e)

	devs[0].appendChild(prettifyElement(dev))
	writeConf(options, doc)

def usage():
	print 'Usage: %s [--config file] --add-device <name> [--no-autodetect]' % os.path.basename(__file__)
	sys.exit(1)

import getopt

try:
	opts, args = getopt.getopt(sys.argv[1:], "hd:nu:c:",
			["help", "add-device=", "add-user=", "config="])
except getopt.GetoptError:
	usage()

if len(args) != 0:
	usage()

options = { 'deviceName' : None, 'userName' : None,
		'configFile' : '/etc/pamusb.conf' }

for o, a in opts:
	if o in ("-h", "--help"):
		usage()
	if o in ("-d", "--add-device"):
		options['deviceName'] = a
	if o in ("-u", "--add-user"):
		options['userName'] = a
	if o in ("-c", "--config"):
		options['configFile'] = a

if options['deviceName'] is not None and options['userName'] is not None:
	print 'You cannot use both --add-user and --add-device'
	usage()

if options['deviceName'] is None and options['userName'] is None:
	usage()

if options['deviceName'] is not None:
	bus = dbus.SystemBus()
	halService = bus.get_object('org.freedesktop.Hal',
			'/org/freedesktop/Hal/Manager')
	halManager = dbus.Interface(halService, 'org.freedesktop.Hal.Manager')
	try:
		addDevice(options)
	except KeyboardInterrupt:
		sys.exit(1)

if options['userName'] is not None:
	try:
		addUser(options)
	except KeyboardInterrupt:
		sys.exit(1)