From 31abee0341cb9d19f0234da7b42dddbabfcd1d4a Mon Sep 17 00:00:00 2001 From: Andrew White Date: Fri, 16 Feb 2018 13:21:48 +0000 Subject: Add support for automatic nonce generation for Rails UJS Because the UJS library creates a script tag to process responses it normally requires the script-src attribute of the content security policy to include 'unsafe-inline'. To work around this we generate a per-request nonce value that is embedded in a meta tag in a similar fashion to how CSRF protection embeds its token in a meta tag. The UJS library can then read the nonce value and set it on the dynamically generated script tag to enable it to execute without needing 'unsafe-inline' enabled. Nonce generation isn't 100% safe - if your script tag is including user generated content in someway then it may be possible to exploit an XSS vulnerability which can take advantage of the nonce. It is however an improvement on a blanket permission for inline scripts. It is also possible to use the nonce within your own script tags by using `nonce: true` to set the nonce value on the tag, e.g <%= javascript_tag nonce: true do %> alert('Hello, World!'); <% end %> Fixes #31689. --- actionview/lib/action_view/helpers.rb | 2 ++ 1 file changed, 2 insertions(+) (limited to 'actionview/lib/action_view/helpers.rb') diff --git a/actionview/lib/action_view/helpers.rb b/actionview/lib/action_view/helpers.rb index 46f20c4277..8cc8013718 100644 --- a/actionview/lib/action_view/helpers.rb +++ b/actionview/lib/action_view/helpers.rb @@ -13,6 +13,7 @@ module ActionView #:nodoc: autoload :CacheHelper autoload :CaptureHelper autoload :ControllerHelper + autoload :CspHelper autoload :CsrfHelper autoload :DateHelper autoload :DebugHelper @@ -46,6 +47,7 @@ module ActionView #:nodoc: include CacheHelper include CaptureHelper include ControllerHelper + include CspHelper include CsrfHelper include DateHelper include DebugHelper -- cgit v1.2.3