Grace period support for TFA

app/controllers/application_controller.rb

@@ -225,9 +225,13 @@ class ApplicationController < ActionController::Base
   end
   def check_tfa_requirement
-    if two_factor_authentication_required? && current_user && !current_user.two_factor_enabled
+    if two_factor_authentication_required? && current_user && !current_user.two_factor_enabled && !skip_two_factor?
+      grace_period_started = current_user.otp_grace_period_started_at
+      grace_period_deadline = grace_period_started + two_factor_grace_period.hours
+
+      deadline_text = "until #{l(grace_period_deadline)}" unless two_factor_grace_period_expired?(grace_period_started)
       redirect_to new_profile_two_factor_auth_path,
-                  alert: 'You must configure Two-Factor Authentication in your account'
+                  alert: "You must configure Two-Factor Authentication in your account #{deadline_text}"
     end
   end
@@ -369,6 +373,18 @@ class ApplicationController < ActionController::Base
     current_application_settings.require_two_factor_authentication
   end
+  def two_factor_grace_period
+    current_application_settings.two_factor_grace_period
+  end
+
+  def two_factor_grace_period_expired?(date)
+    date && (date + two_factor_grace_period.hours) < Time.current
+  end
+
+  def skip_two_factor?
+    session[:skip_tfa] && session[:skip_tfa] > Time.current
+  end
+
   def redirect_to_home_page_url?
     # If user is not signed-in and tries to access root_path - redirect him to landing page
     # Don't redirect to the default URL to prevent endless redirections

app/controllers/profiles/two_factor_auths_controller.rb

@@ -4,8 +4,11 @@ class Profiles::TwoFactorAuthsController < Profiles::ApplicationController
   def new
     unless current_user.otp_secret
       current_user.otp_secret = User.generate_otp_secret(32)
-      current_user.save!
     end
+    unless current_user.otp_grace_period_started_at && two_factor_grace_period
+      current_user.otp_grace_period_started_at = Time.current
+    end
+    current_user.save! if current_user.changed?
     @qr_code = build_qr_code
   end
@@ -36,6 +39,15 @@ class Profiles::TwoFactorAuthsController < Profiles::ApplicationController
     redirect_to profile_account_path
   end
+  def skip
+    if two_factor_grace_period_expired?(current_user.otp_grace_period_started_at)
+      redirect_to new_profile_two_factor_auth_path, alert: 'Cannot skip two factor authentication setup'
+    else
+      session[:skip_tfa] = current_user.otp_grace_period_started_at + two_factor_grace_period.hours
+      redirect_to root_path
+    end
+  end
+
   private
   def build_qr_code

app/helpers/auth_helper.rb

@@ -50,5 +50,17 @@ module AuthHelper
     current_user.identities.exists?(provider: provider.to_s)
   end
+  def two_factor_skippable?
+    current_application_settings.require_two_factor_authentication &&
+      !current_user.two_factor_enabled &&
+      current_application_settings.two_factor_grace_period &&
+      !two_factor_grace_period_expired?
+  end
+
+  def two_factor_grace_period_expired?
+    current_user.otp_grace_period_started_at &&
+      (current_user.otp_grace_period_started_at + current_application_settings.two_factor_grace_period.hours) < Time.current
+  end
+
   extend self
 end

app/views/profiles/two_factor_auths/new.html.haml

@@ -38,3 +38,4 @@
       = text_field_tag :pin_code, nil, class: "form-control", required: true, autofocus: true
   .form-actions
     = submit_tag 'Submit', class: 'btn btn-success'
+    = link_to 'Configure it later', skip_profile_two_factor_auth_path, :method => :patch,  class: 'btn btn-cancel' if two_factor_skippable?

config/routes.rb

@@ -297,6 +297,7 @@ Rails.application.routes.draw do
       resource :two_factor_auth, only: [:new, :create, :destroy] do
         member do
           post :codes
+          patch :skip
         end
       end
     end

db/migrate/20151221234414_add_tfa_additional_fields.rb

+class AddTfaAdditionalFields < ActiveRecord::Migration
+  def change
+    change_table :users do |t|
+      t.datetime :otp_grace_period_started_at, null: true
+    end
+  end
+end

db/schema.rb

@@ -840,6 +840,7 @@ ActiveRecord::Schema.define(version: 20151224123230) do
     t.integer  "layout",                     default: 0
     t.boolean  "hide_project_limit",         default: false
     t.string   "unlock_token"
+    t.datetime "otp_grace_period_started_at"
   end
   add_index "users", ["admin"], name: "index_users_on_admin", using: :btree