#!/usr/bin/env ruby
# -*- coding: binary -*-

#
# Check for data scripts to ensure they are up to date
#
# by h00die
#

require 'digest'
require 'open-uri'
require 'optparse'

options = {}
optparse = OptionParser.new do |opts|
  opts.banner = 'Usage: chececk_external_scripts.rb [options]'
  opts.on('-u', '--update', 'Overwrite old scripts with newer ones.') do
    options[:update] = true
  end
  opts.on('-h', '--help', 'Display this screen.') do
    puts opts
    exit
  end
end
optparse.parse!

# colors and puts templates from msftidy.rb

class String
  def red
    "\e[1;31;40m#{self}\e[0m"
  end

  def yellow
    "\e[1;33;40m#{self}\e[0m"
  end

  def green
    "\e[1;32;40m#{self}\e[0m"
  end

  def cyan
    "\e[1;36;40m#{self}\e[0m"
  end
end

#
# Display an error message, given some text
#
def error(txt)
  line_msg = ''
  puts "[#{'ERROR'.red}] #{cleanup_text(txt)}"
end

#
# Display a warning message, given some text
#
def warn(txt)
  line_msg = ''
  puts "[#{'WARNING'.yellow}] #{cleanup_text(txt)}"
end

#
# Display a info message, given some text
#
def info(txt)
  line_msg = ''
  puts "[#{'INFO'.cyan}] #{cleanup_text(txt)}"
end

def cleanup_text(txt)
  # remove line breaks
  txt = txt.gsub(/[\r\n]/, ' ')
  # replace multiple spaces by one space
  txt.gsub(/\s{2,}/, ' ')
end

#
#
#  Main
#
#

scripts = []
scripts << {
  name: 'Sharphound (Bloodhound)',
  addr: 'https://raw.githubusercontent.com/BloodHoundAD/BloodHound/master/Ingestors/SharpHound.ps1',
  dest: '/data/post/powershell/SharpHound.ps1',
  subs: [
    ["\t", "    "], # tabs to spaces
    [/\s+$/, '']    # trailing whitespace
  ]
}

path = File.expand_path('../../', File.dirname(__FILE__))

scripts.each do |script|
  puts "Downloading: #{script[:name]}"
  begin
    old_content = File.binread(path + script[:dest])
    old_hash = Digest::SHA1.hexdigest old_content
    info "Old Hash: #{old_hash}"

    new_content = open(script[:addr]).read
    if script.key?(:subs) then
      script[:subs].each do |sub|
        new_content.gsub!(sub[0], sub[1])
      end
    end
    new_hash = Digest::SHA1.hexdigest new_content
    info "New Hash: #{new_hash}"

    unless old_hash == new_hash
      warn "  New version identified!"
      if options[:update] == true
        warn "    Updating MSF copy of #{script[:dest]}"
        File.binwrite(path + script[:dest], new_content)
      end
    end
  rescue OpenURI::HTTPError
    error "Unable to download, check URL: #{script[:addr]}"
  rescue Errno::ENOENT
    error "Destination not found, check path: #{path + script[:dest]}"
  end
end