Added captcha for sign up form

• Added:
- captcha for sign up form
- empty ENV variables for: GAB_CAPTCHA_SECRET_KEY, GAB_CAPTCHA_CLIENT_KEY to be configured within captcha.gab.com
- Script insertion within registrations/new.html.haml containing instantiation for captcha.gab.com with our client key and challenge buster
- Div within registration form for #gab-captcha for the challenge to get inserted within
- Checks in RegistrationsController for captcha verification using server token (automatically generated in form), secret [server] key before checking if username/password/email is valid

.env.nanobox

@@ -224,3 +224,7 @@ SMTP_FROM_ADDRESS=notifications@${APP_NAME}.nanoapp.io
 # SAML_UID_ATTRIBUTE="urn:oid:0.9.2342.19200300.100.1.1"
 # SAML_ATTRIBUTES_STATEMENTS_VERIFIED=
 # SAML_ATTRIBUTES_STATEMENTS_VERIFIED_EMAIL=
+
+# Gab Captcha
+GAB_CAPTCHA_SECRET_KEY=
+GAB_CAPTCHA_CLIENT_KEY=

.env.production.sample

@@ -231,3 +231,7 @@ STREAMING_CLUSTER_NUM=1
 # http_proxy=http://gateway.local:8118
 # Access control for hidden service.
 # ALLOW_ACCESS_TO_HIDDEN_SERVICE=true
+
+# Gab Captcha
+GAB_CAPTCHA_SECRET_KEY=
+GAB_CAPTCHA_CLIENT_KEY=

app/controllers/auth/registrations_controller.rb

@@ -3,26 +3,22 @@
 class Auth::RegistrationsController < Devise::RegistrationsController
   layout :determine_layout
 
-  before_action :set_challenge, only: [:new]
   before_action :check_enabled_registrations, only: [:new, :create]
   before_action :configure_sign_up_params, only: [:create]
   before_action :set_sessions, only: [:edit, :update]
   before_action :set_instance_presenter, only: [:new, :create, :update]
   before_action :set_body_classes, only: [:new, :create, :edit, :update]
   before_action :set_cache_headers, only: [:edit, :update]
+  prepend_before_action :check_captcha, only: [:create]
 
   def new
+    set_challenge_buster
     super
   end
 
   def create
-    if session[:challenge_answer].to_s == params[:user][:challenge].to_s.strip
-      # Reset after, may be errors to return and this ensures its still visible
-      set_challenge
-      super
-    else
-      return false
-    end
+    set_challenge_buster
+    super
   end
 
   def destroy
@@ -66,6 +62,18 @@ class Auth::RegistrationsController < Devise::RegistrationsController
 
   private
 
+  def check_captcha
+    unless passed_challenge?(params["gab-captcha-st"], params[:user])
+      self.resource = resource_class.new configure_sign_up_params
+      resource.validate # Look for any other validation errors besides reCAPTCHA
+      flash[:captcha_error] = "Incorrect text. Please try again."
+      set_challenge_buster
+      respond_with_navigational(resource) {
+        redirect_to new_user_registration_path
+      }
+    end 
+  end
+
   def set_instance_presenter
     @instance_presenter = InstancePresenter.new
   end
@@ -74,10 +82,37 @@ class Auth::RegistrationsController < Devise::RegistrationsController
     @body_classes = %w(edit update).include?(action_name) ? 'admin' : ''
   end
 
-  def set_challenge
-    @challenge_add_1 = rand(0...9)
-    @challenge_add_2 = rand(0...9)
-    session[:challenge_answer] = @challenge_add_1 + @challenge_add_2
+  def set_challenge_buster
+    @challenge_buster = SecureRandom.hex
+  end
+
+  def passed_challenge?(serverToken, userParams)
+    # Log if captcha keys not present in ENV
+    if ENV.fetch('GAB_CAPTCHA_CLIENT_KEY', '').empty? || ENV.fetch('GAB_CAPTCHA_CLIENT_KEY', '').nil?
+      Rails.logger.debug "RegistrationsController: GAB_CAPTCHA_CLIENT_KEY is undefined"
+    end
+
+    # Log and return false is captcha key is not present. This will disallow anyone from signing up
+    if ENV.fetch('GAB_CAPTCHA_SECRET_KEY', '').empty? || ENV.fetch('GAB_CAPTCHA_SECRET_KEY', '').nil?
+      Rails.logger.debug "RegistrationsController: GAB_CAPTCHA_SECRET_KEY is undefined"
+      return false
+    end
+
+    typedChallenge = userParams[:challenge]
+    username = userParams[:account_attributes][:username]
+
+    return false if serverToken.nil? || serverToken.empty? || typedChallenge.nil? || typedChallenge.empty?
+    
+    Request.new(:post, "https://captcha.gab.com/captcha/#{serverToken}/verify", form: {
+      "serverKey" => ENV.fetch('GAB_CAPTCHA_SECRET_KEY', ''),
+      "value" => typedChallenge,
+      "username" => username,
+      "ip" => request.env['REMOTE_ADDR']
+    }).perform do |res|
+      body = JSON.parse(res.body_with_limit)
+      result = !!body["success"]
+      return result
+    end
   end
 
   def determine_layout

app/views/auth/registrations/new.html.haml

@@ -5,7 +5,10 @@
   = render partial: 'shared/og'
 
 = simple_form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f|
-  %h2.form-title Sign up for Gab
+  %div{style: "display:flex;flex-direction:row;height:36px;width:100%;align-items:center;margin-bottom:15px;"}
+    %h2.form-title{style: "padding:0;margin:0;"} Sign up for Gab
+    %div{style: "display:flex;width:90px;height:36px;margin-left:auto;margin-top:-10px;"}
+      = f.button :button, t('auth.register'), type: :submit, style: "height:36px;font-size:14px;"
 
   = render 'shared/error_messages', object: resource
 
@@ -22,9 +25,12 @@
   .fields-group
     = f.input :password_confirmation, wrapper: :with_label, label: t('simple_form.labels.defaults.confirm_password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.confirm_password'), :autocomplete => 'off' }
 
-  .fields-group
-    = f.input :challenge, wrapper: :with_label, label: "Are you a human? What is #{@challenge_add_1} + #{@challenge_add_2} = ", required: true, input_html: { 'aria-label' => "Are you a human? What is #{@challenge_add_1} + #{@challenge_add_2}", :autocomplete => 'off' }
-
+  .fields-group{style: "flex-direction:column;"}
+    = f.input :challenge, wrapper: :with_label, label: "Are you a human? Enter the text below.", required: true, input_html: { 'aria-label' => "Are you a human? Enter the text below.", :autocomplete => 'off' }
+    %span{style: "margin-top:5px;font-size:12px;color:red;"}= flash[:captcha_error]
+    %div#gab-captcha{style: "display:block;position:relative;width:240px;height:100px;margin-top:10px;border-radius:6px;overflow:hidden;border:1px solid #ccc;"}
+      %span{style:"display:block;position:absolute;line-height:100px;width:240px;height:100px;top:0;left:0;right:0;bottom:0;text-align:center;color:#ccc;"} •   •   •
+ 
   .fields-group-agreement
     = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', about_tos_path: about_tos_path)
 
@@ -32,3 +38,6 @@
     = f.button :button, t('auth.register'), type: :submit
 
 .form-footer= render 'auth/shared/links'
+
+
+%script{src: "https://captcha.gab.com/captcha/#{ENV.fetch('GAB_CAPTCHA_CLIENT_KEY', '')}/challenge.js?b=#{@challenge_buster}", type: "application/javascript" }