config/initializers/content_security_policy.rb

   1 # Be sure to restart your server when you modify this file.
   2
   3 # Define an application-wide content security policy.
   4 # See the Securing Rails Applications Guide for more information:
   5 # https://guides.rubyonrails.org/security.html#content-security-policy-header
   6
   7 Rails.application.configure do
   8   connect_src = [:self]
   9   img_src = [:self, :data, "www.gravatar.com", "*.wp.com", "tile.openstreetmap.org", "*.tile.thunderforest.com", "tile.tracestrack.com", "*.openstreetmap.fr"]
  10   script_src = [:self]
  11
  12   connect_src << Settings.matomo["location"] if defined?(Settings.matomo)
  13   img_src << Settings.matomo["location"] if defined?(Settings.matomo)
  14   script_src << Settings.matomo["location"] if defined?(Settings.matomo)
  15
  16   img_src << Settings.avatar_storage_url if Settings.key?(:avatar_storage_url)
  17   img_src << Settings.trace_image_storage_url if Settings.key?(:trace_image_storage_url)
  18
  19   config.content_security_policy do |policy|
  20     policy.default_src :self
  21     policy.child_src(:self)
  22     policy.connect_src(*connect_src)
  23     policy.font_src(:none)
  24     policy.form_action(:self)
  25     policy.frame_ancestors(:self)
  26     policy.frame_src(:self)
  27     policy.img_src(*img_src)
  28     policy.manifest_src(:self)
  29     policy.media_src(:none)
  30     policy.object_src(:self)
  31     policy.plugin_types
  32     policy.script_src(*script_src)
  33     policy.style_src(:self)
  34     policy.worker_src(:none)
  35     policy.manifest_src(:self)
  36     policy.report_uri(Settings.csp_report_url) if Settings.key?(:csp_report_url)
  37   end
  38
  39   # Generate session nonces for permitted importmap and inline scripts
  40   config.content_security_policy_nonce_generator = ->(_request) { SecureRandom.base64(24) }
  41   config.content_security_policy_nonce_directives = %w[style-src]
  42
  43   # Report violations without enforcing the policy.
  44   config.content_security_policy_report_only = true unless Settings.csp_enforce
  45 end