config/initializers/content_security_policy.rb

   1 # Define an application-wide content security policy
   2 # For further information see the following documentation
   3 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
   4
   5 def host_to_url(str)
   6   "http#{Rails.configuration.x.use_https ? 's' : ''}://#{str}" unless str.blank?
   7 end
   8
   9 base_host = Rails.configuration.x.web_domain
  10
  11 assets_host   = Rails.configuration.action_controller.asset_host
  12 assets_host ||= host_to_url(base_host)
  13
  14 media_host   = host_to_url(ENV['S3_ALIAS_HOST'])
  15 media_host ||= host_to_url(ENV['S3_CLOUDFRONT_HOST'])
  16 media_host ||= host_to_url(ENV['S3_HOSTNAME']) if ENV['S3_ENABLED'] == 'true'
  17 media_host ||= assets_host
  18
  19 Rails.application.config.content_security_policy do |p|
  20   p.base_uri        :none
  21   p.default_src     :none
  22   p.frame_ancestors :none
  23   p.font_src        :self, assets_host
  24   p.img_src         :self, :https, :data, :blob, assets_host
  25   p.style_src       :self, assets_host
  26   p.media_src       :self, :https, :data, assets_host
  27   p.frame_src       :self, :https
  28   p.manifest_src    :self, assets_host
  29
  30   if Rails.env.development?
  31     webpacker_urls = %w(ws http).map { |protocol| "#{protocol}#{Webpacker.dev_server.https? ? 's' : ''}://#{Webpacker.dev_server.host_with_port}" }
  32
  33     p.connect_src :self, :data, :blob, assets_host, media_host, Rails.configuration.x.streaming_api_base_url, *webpacker_urls
  34     p.script_src  :self, :unsafe_inline, :unsafe_eval, assets_host
  35     p.child_src   :self, :blob, assets_host
  36     p.worker_src  :self, :blob, assets_host
  37   else
  38     p.connect_src :self, :data, :blob, assets_host, media_host, Rails.configuration.x.streaming_api_base_url
  39     p.script_src  :self, assets_host
  40     p.child_src   :self, :blob, assets_host
  41     p.worker_src  :self, :blob, assets_host
  42   end
  43 end
  44
  45 # Report CSP violations to a specified URI
  46 # For further information see the following documentation:
  47 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
  48 # Rails.application.config.content_security_policy_report_only = true
  49
  50 Rails.application.config.content_security_policy_nonce_generator = -> request { SecureRandom.base64(16) }
  51
  52 Rails.application.config.content_security_policy_nonce_directives = %w(style-src)
  53
  54 PgHero::HomeController.content_security_policy do |p|
  55   p.script_src :self, :unsafe_inline, assets_host
  56   p.style_src  :self, :unsafe_inline, assets_host
  57 end
  58
  59 PgHero::HomeController.after_action do
  60   request.content_security_policy_nonce_generator = nil
  61 end