# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# Mobius Forensic Toolkit
# Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020 Eduardo Aguiar
#
# 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, 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, see <http://www.gnu.org/licenses/>.
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
import mobius
import pymobius.registry.main
import pymobius.operating_system
import binascii
import traceback

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# @brief Generic dataholder class
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
class dataholder (object):
  pass

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# @brief Ant: turing.dpapi_sys_mk
# @author Eduardo Aguiar
# Retrieves and decrypts DPAPI System Master Keys
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
class Ant (object):

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Initialize object
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __init__ (self, item):
    self.name = 'Turing DPAPI System Master Keys'
    self.version = '1.0'
    self.__item = item

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Run ant
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def run (self):
    self.__dpapi_system = []
    self.__keys = []
    self.__count = 0

    try:
      ant = pymobius.registry.main.Ant (self.__item)

      for registry in ant.get_data ():
        self.__retrieve_dpapi_system_from_registry (registry)
    except Exception, e:
      mobius.core.log ('WRN %s' % str (e))

    try:
      self.__retrieve_dpapi_system_master_keys_files ()
    except Exception, e:
      mobius.core.log ('WRN %s' % str (e))

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Event <i>on_export_data</i>: Export data to mediator ant
  # @param ant Mediator ant object
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def on_export_data (self, ant):
    for key in self.__keys:
      ant.add_key (key)

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Event <i>on_stop</i>: Terminate this ant
  # @param ant Mediator ant object
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def on_stop (self, ant):
    mobius.core.log ('INF ant.turing: %d/%d system master key(s) decrypted' % (len (self.__keys), self.__count))

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Retrieve DPAPI_SYSTEM values from registry
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __retrieve_dpapi_system_from_registry (self, registry):
    key = registry.get_key_by_path ('\\HKLM\\SECURITY\\Policy\\Secrets\\DPAPI_SYSTEM')

    if key:
      data = key.get_data_by_path ('CurrVal\\(default)')
      self.__retrieve_dpapi_system_from_value (data)

      data = key.get_data_by_path ('OldVal\\(default)')
      self.__retrieve_dpapi_system_from_value (data)

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Decoder DPAPI_SYSTEM value
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __retrieve_dpapi_system_from_value (self, data):

    if data and data.size == 44:
      decoder = mobius.decoder.data_decoder (data.data)

      revision = decoder.get_uint32_le ()
      local_credential = decoder.get_bytearray_by_size (20)
      user_credential = decoder.get_bytearray_by_size (20)
    
      if local_credential not in self.__dpapi_system:
        self.__dpapi_system.append (local_credential)

      if user_credential not in self.__dpapi_system:
        self.__dpapi_system.append (user_credential)

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Retrieve and decrypt DPAPI system master keys
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __retrieve_dpapi_system_master_keys_files (self):
    for opsys in pymobius.operating_system.scan (self.__item):
      for root in opsys.get_root_folders ():
        folder = root.get_child_by_path ('windows/system32/microsoft/protect/s-1-5-18')
        if folder:
          self.__retrieve_dpapi_system_master_keys_from_folder (folder)

          folder = folder.get_child_by_name ('User')
          if folder:
            self.__retrieve_dpapi_system_master_keys_from_folder (folder)

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Retrieve and decrypt DPAPI system master keys from folder
  # @param folder Folder
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __retrieve_dpapi_system_master_keys_from_folder (self, folder):
    for child in folder.get_children ():
      if child.is_file () and child.name.count ('-') == 4:
        try:
          self.__retrieve_dpapi_system_master_key_from_file (child)
        except Exception, e:
          mobius.core.log ('WRN turing.dpapi_sys_mk: ' + str (e) + ' ' + traceback.format_exc ())

  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Retrieve and decrypt DPAPI system master key from file
  # @param f File
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __retrieve_dpapi_system_master_key_from_file (self, f):

    # parse master key file
    reader = f.new_reader ()
    if not reader:
      return

    mkf = mobius.os.win.dpapi.master_key_file (reader)
    if not mkf:
      return

    self.__count += 1
    f.set_handled ()

    # try to decrypt using DPAPI_SYSTEM keys
    mk = mkf.master_key

    for key in self.__dpapi_system:
      mk.decrypt_with_key (key)

      if mk.is_decrypted ():
        key = self.__create_key (f, mkf, mk)
        self.__keys.append (key)
        return

    mobius.core.log ('INF ant.turing: Sys mk not decrypted: ' + mkf.guid)
    
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  # @brief Create DPAPI sys key
  # =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  def __create_key (self, f, mkf, mk):
    key = dataholder ()
    key.type = 'dpapi.sys'
    key.id = mkf.guid
    key.value = mk.plain_text

    key.metadata = []
    key.metadata.append (('source', f.path.replace ('/', '\\')))
    key.metadata.append (('DPAPI GUID', mkf.guid))
    key.metadata.append (('Revision', mk.revision))
    key.metadata.append (('Salt', binascii.hexlify (mk.salt)))
    key.metadata.append (('Iterations', mk.iterations))
    key.metadata.append (('Hash ID', '(0x%04x)' % mk.hash_id))
    key.metadata.append (('Cipher ID', '(0x%04x)' % mk.cipher_id))
    key.metadata.append (('Flags',  mk.flags))

    return key
