Tor blocker

0 - Intro.md

Tor blocker for Rails

Live app: http://runnable.com/VASQX76Fg-9atbmM/rails-tor-blocker

Not tested

1 - tor_blacklist.rb

class TorBlacklist
  attr_accessor :current_mtime

  def self.tor_ips?(ip)
    ips.include?(ip)
  end

  def self.ips
    reset if file_updated?
    @ips ||= read_blacklist_file.map(&:strip)
  end

  def self.read_blacklist_file
    self.current_mtime = File.stat(blacklist_file_path).mtime
    IO.readlines(blacklist_file_path)
  end

  def self.blacklist_file_path(root = Rails.root)
    root.join("db/tor.db")
  end

  def self.file_updated?
    current_mtime and (current_mtime < new_mtime)
  end

  def self.reset
    @ips = nil
  end

  def self.new_mtime
    File.stat(blacklist_file_path).mtime
  end
end

2 - get_tor_ips.rake

task :get_tor_ips do
  system("wget -q https://dan.me.uk/torlist/ -O #{Rails.root}/db/tor.db")
end

3 - application_controller.rb

class ApplicationController < ActionController::Base
  before_action :block_tor

  def block_tor
    @tor_ips = IO.readlines("#{Rails.root}/db/tor.db").map(&:strip)

    if @tor_ips.include? request.remote_ip
      render "layouts/blocked_tor", layout: false
    end
  end
end

4 - blocked_tor.html.erb

<!-- TODO: I18n -->

<h1>Access denied: Tor</h1> 

5 - tor_blacklist_test.rb

require "test_helper"
require "tor_blacklist"

describe TorBlacklist do
  let(:file_contents) do
    <<LIST
192.168.1.1
192.168.1.2
192.168.1.3
192.168.1.4
LIST
  end

  subject { TorBlacklist }

  after(:each) do
    subject.reset
  end

  describe ".ips" do
    it "parses the IPs from a blacklist file" do
      list_of_ips = file_contents.split
      subject.expects(:read_blacklist_file).returns(list_of_ips)
      subject.ips.must_equal %w( 192.168.1.1 192.168.1.2 192.168.1.3 192.168.1.4 )
    end

    it "does not open the file again once it is read" do
      subject.expects(:read_blacklist_file).once.returns([])
      subject.ips
      subject.ips
    end

    it "re-parses the IPs from the blacklist file when it is updated" do
      subject.expects(:read_blacklist_file).twice.returns([])
      subject.ips
      subject.stubs(:file_updated?).returns(true)
      subject.ips
    end
  end

  describe ".tor_ips?" do
    it "returns true if the supplied IP is on the list" do
      subject.stubs(:ips).returns(["192.168.1.1"])
      subject.tor_ips?("192.168.1.1").should be_true
    end

    it "returns false if the IP is not included on the list" do
      subject.stubs(:ips).returns(["192.168.1.1"])
      subject.tor_ips?("192.168.1.2").should be_false
    end
  end

  describe ".read_blacklist_file" do
    before(:each) do
      subject.stubs(:blacklist_file_path).returns(Pathname.new("./spec/fixtures/tor.db"))
    end

    it "reads the file" do
      contents = subject.read_blacklist_file
      contents.should be_an Array
      contents.should have(4).lines
    end
  end

  describe ".blacklist_file_path" do
    it "defaults to db/tor.db" do
      root = Pathname.new(".")
      subject.blacklist_file_path(root).must_equal root.join("db/tor.db")
    end
  end

  describe ".file_updated?" do
    it "returns false if the file has not been read yet" do
      subject.stubs(:current_mtime).returns(nil)
      subject.file_updated?.should be_false
    end

    it "returns true if mtime of the file has changed" do
      subject.stubs(:current_mtime).returns(Time.now)
      subject.stubs(:new_mtime).returns(Time.now)
      subject.file_updated?.should be_true
    end

    it "returns false the file has not changed" do
      time = Time.now
      subject.stubs(:current_mtime).returns(time)
      subject.stubs(:new_mtime).returns(time)
      subject.file_updated?.should be_false
    end
  end
end