Add IP block on authentication via EID

Also, correct mistakenly used 403 error code.
Update aplication-example.yml to include new functionality.

app/controllers/api/v1/registrant/auth_controller.rb

@@ -5,6 +5,8 @@ module Api
   module V1
     module Registrant
       class AuthController < ActionController::API
+        before_action :check_ip_whitelist
+
         rescue_from(ActionController::ParameterMissing) do |parameter_missing_exception|
           error = {}
           error[parameter_missing_exception.param] = ['parameter is required']
@@ -39,6 +41,14 @@ module Api
           hash = token_creator.token_in_hash
           hash
         end
+
+        def check_ip_whitelist
+          allowed_ips = ENV['registrant_api_auth_allowed_ips'].to_s.split(',').map(&:strip)
+
+          unless allowed_ips.include?(request.ip) || Rails.env.development?
+            render json: { error: 'Not authorized' }, status: 401
+          end
+        end
       end
     end
   end

app/controllers/api/v1/registrant/base_controller.rb

@@ -7,6 +7,13 @@ module Api
       class BaseController < ActionController::API
         before_action :authenticate
 
+        rescue_from(ActionController::ParameterMissing) do |parameter_missing_exception|
+          error = {}
+          error[parameter_missing_exception.param] = ['parameter is required']
+          response = { errors: [error] }
+          render json: response, status: :unprocessable_entity
+        end
+
         private
 
         def bearer_token
@@ -22,7 +29,7 @@ module Api
           if decryptor.valid?
             sign_in decryptor.user
           else
-            render json: { error: 'Not authorized' }, status: 403
+            render json: { error: 'Not authorized' }, status: 401
           end
         end
       end

app/controllers/api/v1/registrant/domains_controller.rb

@@ -7,11 +7,11 @@ module Api
       class DomainsController < BaseController
         def index
           registrant = ::Registrant.find_by(ident: current_user.registrant_ident)
-          unless registrant
-            render json: Domain.all
-          else
+          if registrant
             domains = Domain.where(registrant_id: registrant.id)
             render json: domains
+          else
+            render json: []
           end
         end
       end