Implement U2F registration.

- Move the `TwoFactorAuthsController`'s `new` action to `show`, since
  the page is not used to create a single "two factor auth" anymore. We
  can have a single 2FA authenticator app, along with any number of U2F
  devices, in any combination, so the page will be accessed after the
  first "two factor auth" is created.
- Add the `u2f` javascript library, which provides an API to the
  browser's U2F implementation.
- Add tests for the JS components

1 files changed, 11 insertions, 0 deletions

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index e73b2d08551..62f63701799 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -342,6 +342,10 @@ class ApplicationController < ActionController::Base
     session[:skip_tfa] && session[:skip_tfa] > Time.current
   end
 
+  def browser_supports_u2f?
+    browser.chrome? && browser.version.to_i >= 41 && !browser.device.mobile?
+  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
@@ -355,6 +359,13 @@ class ApplicationController < ActionController::Base
     current_user.nil? && root_path == request.path
   end
 
+  # U2F (universal 2nd factor) devices need a unique identifier for the application
+  # to perform authentication.
+  # https://developers.yubico.com/U2F/App_ID.html
+  def u2f_app_id
+    request.base_url
+  end
+
   private
 
   def set_default_sort