config/initializers/content_security_policy.rb
# Be sure to restart your server when you modify this file.
# Define an application-wide content security policy.
# See the Securing Rails Applications Guide for more information:
# https://guides.rubyonrails.org/security.html#content-security-policy-header
Rails.application.configure do
config.content_security_policy do |policy|
policy.default_src :self, :https
policy.font_src :self, :https, :data
policy.img_src :self, :https, :data
policy.object_src :none
# TODO: unsafe_inline should be removed but this cannot be done until some Javascript is refactored.
policy.script_src :self, "'wasm-unsafe-eval'", :unsafe_inline, :https
policy.style_src :self, :unsafe_inline, :https
# Specify URI for violation reports
policy.report_uri "/csp_report"
end
# Generate session nonces for permitted importmap and inline scripts
# TODO: Enable these options. This can only be done when unsafe_inline is removed above.
# config.content_security_policy_nonce_generator = ->(request) { request.session.id.to_s }
# config.content_security_policy_nonce_directives = %w(script-src)
# Report violations without enforcing the policy.
config.content_security_policy_report_only = true
end