#!/usr/bin/ruby

## docxtract v0.1 : Extract files from docx document
## Copyright (C) 2009  Franck GUENICHOT
## franck {dot} guenichot {at} orange {dot} fr
##
## 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 3
## of the License, or any later version.
##
## 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 3 of the License, or
## 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/>.

## Written for the Network Forensic Puzzle #2
## http://forensicscontest.com

require 'rubygems'
require 'zip/zip'
require 'zip/zipfilesystem'
require 'digest/md5'
require 'optparse'

$VERSION = "0.1"


# USeful funcs.

def md5sum(file)
  #Calculate md5sum of a file
  digest = Digest::MD5.hexdigest(File.read(file))
  digest
end


#################################################################################################

# handle command line args
options = {}
opts = OptionParser.new do|opts|
  opts.banner = "
    docxtract version #{$VERSION} 
    Copyright (C) 2009 Franck GUENICHOT
    docxtract comes with ABSOLUTELY NO WARRANTY;
    This is free software, and you are welcome
    to redistribute it under certain conditions.
    (GPL v3)	

    Usage: docxtract -x [-i] [-d <path>] <filename>"

  options[:xtract] = false
  opts.on( '-x', '--xtract', 'xtract files (by default to current dir)' ) do
    options[:xtract] = true
  end

  options[:img_only] = false
  opts.on( '-i', '--img_only', '(extract) images only' ) do
    options[:img_only] = true
  end

  options[:md5sum] = false
    opts.on( '-m', '--md5', 'Display extracted file MD5 Hash' ) do
    options[:md5sum] = true
  end  

  options[:destdir] = nil
  opts.on( '-d', '--destdir DIR', 'define destination DIR' ) do|dir|
    options[:destdir] = dir
  end

  opts.on( '-h', '--help', 'Display this screen' ) do
    puts opts
    exit
  end
end

#parse command line args
opts.parse!

$filename = ARGV[ARGV.length-1]


# if no file in input => display help and exit
if $filename == nil
  puts opts
  exit(0)
end

unless File.exist?($filename)
  puts "File: #{$filename} does not exist."
  exit(0)
end

begin
if options[:xtract] then
  
  # open docx file
  
  Zip::ZipFile.open($filename) do |zipfile|
    zipfile.each {|file|
      if options[:destdir] then
        destpath = File.join(options[:destdir],file.name)
      else
	destpath = file.name.gsub('word/media/',"")
      end			
      
      if options[:img_only] then
        if file.name =~ /word\/media\/.*$/ then
	  puts "Extracting: #{file.name.gsub('word/media/',"")} (#{file.size} bytes)"
	  FileUtils.mkpath(File.dirname(destpath.gsub('word/media/',"")))
	  file.extract(destpath.gsub('word/media/',""),&proc{true})
	  if options[:md5sum] then
	      md5 = md5sum(destpath)
	      puts "MD5: #{md5}"
	  end
	end
      else
	puts "Extracting: #{file.name} (#{file.size} bytes)"
	#create dir
	FileUtils.mkpath(File.dirname(destpath))
	zipfile.extract(file,destpath)
	if options[:md5sum] then
	      md5 = md5sum(destpath)
	      puts "MD5: #{md5}"
	end
      end
    }
  end
else
  puts opts
end

rescue => exception
  puts "An error occurred"
  puts exception
end	

#################################################################################################
# END of docxtract										#
#################################################################################################