Module: Raptcha

Defined in:

lib/raptcha.rb,
lib/raptcha.rb

Overview

the command line code

Defined Under Namespace

Modules: Encoder, Encryptor, Image Classes: BadInput, CLI, Error, Expired, NoInput

Constant Summary

README =

<<-__
  NAME
    raptcha.rb

  SYNOPSIS
    super low drain bamage, K.I.S.S., storage-less, session-less,
    plugin-less, dependency-less, zero admin, single-source-file secure
    captcha system for ruby and/or rails.

    bitchin.

  DESCRIPTION
    raptcha manages image generation via a streaming controller.  the result
    is that *no* disk storage is ever needed for captcha images.  it also
    manages authentication via openssl(aes-256) encoded hidden fields which
    are relayed through the form submission process, obviating the need for
    session/database interaction for captcha validation.  the library is
    useful outside of rails, even from the command line.

    what this means to you is that you can have a nice looking, and easy to
    customize, safe captcha solution in about 1 minute that requires zero
    maintenance moving forward.

    see a sample image here
      http://github.com/ahoward/raptcha/blob/master/images/raptcha.png

  INSTALL
    1) INSTALL Image Magick 
        ~> which convert

    2) COPY A SINGLE FILE INTO YOUR RAILS APP
        ~> cp raptcha.rb ./app/lib/

    3) GENERATE THE CONROLLER
        ruby lib/raptcha.rb generate controller

    4) ADD A ROUTE
        match 'raptcha(/:action)', :controller => 'raptcha'

    5) PUT A RAPTCHA IMAGE AND FORM INPUT IN YOUR VIEW
        <%= Raptcha.input %>

    6) REQUIRE VALID RAPTCHA INPUT IN A CONTROLLER ACTION
        class SessionsController < ApplicationController
          def create 
            unless Raptcha.valid?(params)
              # ...
            end
          end
        end

    7) TRY THE EXAMPLES LOCALLY AT
        http://0.0.0.0:3000/raptcha/form
        http://0.0.0.0:3000/raptcha/inline

  URIS
    http://github.com/ahoward/raptcha
    http://codforpeople.com


  COMMAND LINE USAGE
    * make an image by hand
      ~> ruby lib/raptcha.rb image foreground:pink raptcha.png && open raptcha.png

    * generate the controller
      ~> ruby lib/rapcha.rb generate controller

  DOC
    less lib/raptcha.rb
__

Version =

'2.0.0'

Class Method Summary

• .alphabet ⇒ Object
• .close_enough ⇒ Object
• .fuzzy(word) ⇒ Object
• .fuzzy_match(a, b) ⇒ Object
• .gravity ⇒ Object
• .image(*args, &block) ⇒ Object
• .img(options = {}) ⇒ Object
• .inline(options = {}) ⇒ Object
• .input(options = {}) ⇒ Object (also: tag)
• .key ⇒ Object
• .normalize(options) ⇒ Object
• .render(controller, params) ⇒ Object
• .route ⇒ Object
• .timebomb ⇒ Object
• .ttl ⇒ Object
• .valid?(params) ⇒ Boolean
• .validate!(params) ⇒ Object
• .version ⇒ Object
• .word(size = 6) ⇒ Object

Class Method Details

.alphabet ⇒ Object

# File 'lib/raptcha.rb', line 369

def alphabet
  @alphabet ||= ('A' .. 'Z').to_a
end

.close_enough ⇒ Object

# File 'lib/raptcha.rb', line 227

def close_enough
  @close_enough ||= {
    '0OoQ' => '0',
    '1l'   => '1',
    '2zZ'  => '2',
    '5sS'  => '5',
    'kKxX' => 'x',
  }
end

.fuzzy(word) ⇒ Object

# File 'lib/raptcha.rb', line 283

def fuzzy(word)
  result = word.to_s.downcase
  close_enough.each do |charset, replace|
    result.gsub!(%r"[#{ charset }]", replace)
  end
  result.upcase.strip
end

.fuzzy_match(a, b) ⇒ Object

# File 'lib/raptcha.rb', line 291

def fuzzy_match(a, b)
  fuzzy(a) == fuzzy(b)
end

.gravity ⇒ Object

# File 'lib/raptcha.rb', line 219

def gravity
  @gravity ||= 'north'
end

.image(*args, &block) ⇒ Object

# File 'lib/raptcha.rb', line 373

def image(*args, &block)
  Raptcha::Image.create(*args, &block)
end

.img(options = {}) ⇒ Object

# File 'lib/raptcha.rb', line 341

def img(options = {})
  options = Raptcha.normalize(options)
  return(inline(options)) if options[:inline]
  route = options[:route] || Raptcha.route
  word = options[:word] || Raptcha.word
  encrypted_word = Encryptor.encrypt(word)
  %[
    <img src="#{ route }?e=#{ encrypted_word }" alt="raptcha.png" class="raptcha-image"/>
  ]
end

.inline(options = {}) ⇒ Object

# File 'lib/raptcha.rb', line 352

def inline(options = {})
  options = Raptcha.normalize(options)
  %[
    <img src="data:image/png;base64,#{ Image.inline(options)  }" alt="raptcha.png" class="raptcha-image"/>
  ]
end

.input(options = {}) ⇒ Object Also known as: tag

# File 'lib/raptcha.rb', line 295

def input(options = {})
  options = Raptcha.normalize(options)

  options[:route] ||= Raptcha.route
  options[:word] ||= Raptcha.word
  options[:timebomb] ||= Raptcha.timebomb
  options[:gravity] ||= Raptcha.gravity

  encrypted_word = Encryptor.encrypt(options[:word])
  encrypted_timebomb = Encryptor.encrypt(options[:timebomb])

  west = north = east = south = nil

  case gravity.to_s
    when /w(est)?/
      west = Raptcha.img(options)
    when /n(orth)?/
      north = Raptcha.img(options) + '<br>'
    when /e(ast)?/
      east = Raptcha.img(options)
    when /s(outh)?/
      south = '<br>' + Raptcha.img(options)
  end

  html =
    <<-html
      <div class="raptcha">
        #{ north } #{ west }
        <input type="textarea" name="raptcha[t]" value="" class="raptcha-input"/>
        <input type="hidden" name="raptcha[w]" value="#{ encrypted_word }" class="raptcha-word"/>
        <input type="hidden" name="raptcha[b]" value="#{ encrypted_timebomb }" class="raptcha-timebomb"/>
        #{ east } #{ south }
      </div>
    html

  singleton_class =
    class << html
      self
    end
  word = options[:word]
  singleton_class.send(:define_method, :word){ word }

  html
end

.key ⇒ Object

# File 'lib/raptcha.rb', line 211

def key
  @key ||= Rails::Application.config.secret_token
end

.normalize(options) ⇒ Object

# File 'lib/raptcha.rb', line 237

def normalize(options)
  options.inject({}){|h, kv| h.update(kv.first.to_s.to_sym => kv.last) }
end

.render(controller, params) ⇒ Object

# File 'lib/raptcha.rb', line 377

def render(controller, params)
  controller.instance_eval do
    send_data(Raptcha.image(params), :type => 'image/png', :disposition => 'inline', :filename => 'raptcha.png')
  end
end

.route ⇒ Object

# File 'lib/raptcha.rb', line 215

def route
  @route ||= '/raptcha'
end

.timebomb ⇒ Object

# File 'lib/raptcha.rb', line 359

def timebomb
  Time.now.utc.to_i + Raptcha.ttl
end

.ttl ⇒ Object

# File 'lib/raptcha.rb', line 223

def ttl
  @ttl ||= 30 * 60
end

.valid?(params) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/raptcha.rb', line 241

def valid?(params)
  begin
    validate!(params)
  rescue NoInput
    nil
  rescue BadInput, Expired
    false
  end
end

.validate!(params) ⇒ Object

# File 'lib/raptcha.rb', line 251

def validate!(params)
  params = Raptcha.normalize(params)

  if params.has_key?(:raptcha)
    raptcha = params[:raptcha]

    textarea = raptcha[:t]
    word = raptcha[:w]
    timebomb = raptcha[:b]

    raise NoInput unless(textarea and word and timebomb)

    word = Encryptor.decrypt(word)
    timebomb = Encryptor.decrypt(timebomb)

    begin
      timebomb = Integer(timebomb)
      timebomb = Time.at(timebomb).utc
      now = Time.now.utc
      raise Expired unless now < timebomb
    rescue
      raise Expired
    end

    raise BadInput unless fuzzy_match(word, textarea)

    textarea
  else
    validate!(:raptcha => params)
  end
end

.version ⇒ Object

# File 'lib/raptcha.rb', line 77

def Raptcha.version() Version end

.word(size = 6) ⇒ Object

# File 'lib/raptcha.rb', line 363

def word(size = 6)
  word = ''
  size.times{ word << alphabet[rand(alphabet.size - 1)]}
  word
end