Merge pull request #31162 from rails/add-csp-config

Add DSL for configuring Content-Security-Policy header

2 files changed, 198 insertions, 0 deletions

diff --git a/railties/test/application/content_security_policy_test.rb b/railties/test/application/content_security_policy_test.rb
new file mode 100644
index 0000000000..97f2957c33
--- /dev/null
+++ b/railties/test/application/content_security_policy_test.rb
@@ -0,0 +1,197 @@
+# frozen_string_literal: true
+
+require "isolation/abstract_unit"
+require "rack/test"
+
+module ApplicationTests
+  class ContentSecurityPolicyTest < ActiveSupport::TestCase
+    include ActiveSupport::Testing::Isolation
+    include Rack::Test::Methods
+
+    def setup
+      build_app
+    end
+
+    def teardown
+      teardown_app
+    end
+
+    test "default content security policy is empty" do
+      controller :pages, <<-RUBY
+        class PagesController < ApplicationController
+          def index
+            render html: "<h1>Welcome to Rails!</h1>"
+          end
+        end
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          root to: "pages#index"
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_equal ";", last_response.headers["Content-Security-Policy"]
+    end
+
+    test "global content security policy in an initializer" do
+      controller :pages, <<-RUBY
+        class PagesController < ApplicationController
+          def index
+            render html: "<h1>Welcome to Rails!</h1>"
+          end
+        end
+      RUBY
+
+      app_file "config/initializers/content_security_policy.rb", <<-RUBY
+        Rails.application.config.content_security_policy do |p|
+          p.default_src :self, :https
+        end
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          root to: "pages#index"
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_policy "default-src 'self' https:;"
+    end
+
+    test "global report only content security policy in an initializer" do
+      controller :pages, <<-RUBY
+        class PagesController < ApplicationController
+          def index
+            render html: "<h1>Welcome to Rails!</h1>"
+          end
+        end
+      RUBY
+
+      app_file "config/initializers/content_security_policy.rb", <<-RUBY
+        Rails.application.config.content_security_policy do |p|
+          p.default_src :self, :https
+        end
+
+        Rails.application.config.content_security_policy_report_only = true
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          root to: "pages#index"
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_policy "default-src 'self' https:;", report_only: true
+    end
+
+    test "override content security policy in a controller" do
+      controller :pages, <<-RUBY
+        class PagesController < ApplicationController
+          content_security_policy do |p|
+            p.default_src "https://example.com"
+          end
+
+          def index
+            render html: "<h1>Welcome to Rails!</h1>"
+          end
+        end
+      RUBY
+
+      app_file "config/initializers/content_security_policy.rb", <<-RUBY
+        Rails.application.config.content_security_policy do |p|
+          p.default_src :self, :https
+        end
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          root to: "pages#index"
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_policy "default-src https://example.com;"
+    end
+
+    test "override content security policy to report only in a controller" do
+      controller :pages, <<-RUBY
+        class PagesController < ApplicationController
+          content_security_policy_report_only
+
+          def index
+            render html: "<h1>Welcome to Rails!</h1>"
+          end
+        end
+      RUBY
+
+      app_file "config/initializers/content_security_policy.rb", <<-RUBY
+        Rails.application.config.content_security_policy do |p|
+          p.default_src :self, :https
+        end
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          root to: "pages#index"
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_policy "default-src 'self' https:;", report_only: true
+    end
+
+    test "global content security policy added to rack app" do
+      app_file "config/initializers/content_security_policy.rb", <<-RUBY
+        Rails.application.config.content_security_policy do |p|
+          p.default_src :self, :https
+        end
+      RUBY
+
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+
+          app = ->(env) {
+            [200, { "Content-Type" => "text/html" }, ["<p>Hello, World!</p>"]]
+          }
+
+          root to: app
+        end
+      RUBY
+
+      app("development")
+
+      get "/"
+      assert_policy "default-src 'self' https:;"
+    end
+
+    private
+
+      def assert_policy(expected, report_only: false)
+        assert_equal 200, last_response.status
+
+        if report_only
+          expected_header = "Content-Security-Policy-Report-Only"
+          unexpected_header = "Content-Security-Policy"
+        else
+          expected_header = "Content-Security-Policy"
+          unexpected_header = "Content-Security-Policy-Report-Only"
+        end
+
+        assert_nil last_response.headers[unexpected_header]
+        assert_equal expected, last_response.headers[expected_header]
+      end
+  end
+end
diff --git a/railties/test/application/middleware_test.rb b/railties/test/application/middleware_test.rb
index 0a5a524692..470a5326c6 100644
--- a/railties/test/application/middleware_test.rb
+++ b/railties/test/application/middleware_test.rb
@@ -42,6 +42,7 @@ module ApplicationTests
         "ActionDispatch::Cookies",
         "ActionDispatch::Session::CookieStore",
         "ActionDispatch::Flash",
+        "ActionDispatch::ContentSecurityPolicy::Middleware",
         "Rack::Head",
         "Rack::ConditionalGet",
         "Rack::ETag"