```ruby
# Be sure to restart your server when you modify this file.

# Define an application-wide content security policy
# For further information see the following documentation
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy

Rails.application.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
  policy.script_src  :self, :https
  policy.style_src   :self, :https

  # Specify URI for violation reports
  # policy.report_uri "/csp-violation-report-endpoint"
end

# If you are using UJS then enable automatic nonce generation
Rails.application.config.content_security_policy_nonce_generator = -> (request) do
  # use the same csp nonce for turbolinks requests
  if request.env['HTTP_TURBOLINKS_REFERRER'].present?
    request.env['HTTP_X_TURBOLINKS_NONCE']
  else
    SecureRandom.base64(16)
  end
end

# Report CSP violations to a specified URI
# For further information see the following documentation:
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
# Rails.application.config.content_security_policy_report_only = true
```

Check for content security policy support in sandbox
user
```ruby
# Be sure to restart your server when you modify this file.

if Rails.application.config.respond_to?(:content_security_policy)
  # Define an application-wide content security policy
  # For further information see the following documentation
  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
  Rails.application.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
    policy.script_src  :self, :https
    policy.style_src   :self, :https

    # Specify URI for violation reports
    # policy.report_uri "/csp-violation-report-endpoint"
  end

  # If you are using UJS then enable automatic nonce generation
  Rails.application.config.content_security_policy_nonce_generator = -> (request) do
    # use the same csp nonce for turbolinks requests
    if request.env['HTTP_TURBOLINKS_REFERRER'].present?
      request.env['HTTP_X_TURBOLINKS_NONCE']
    else
      SecureRandom.base64(16)
    end
  end

  # Report CSP violations to a specified URI
  # For further information see the following documentation:
  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
  # Rails.application.config.content_security_policy_report_only = true
end
```
assistant