discourse/spec/lib/content_security_policy_spec.rb

# frozen_string_literal: true
require 'rails_helper'

describe ContentSecurityPolicy do
  after do
    DiscoursePluginRegistry.reset!
  end

  describe 'report-uri' do
    it 'is enabled by SiteSetting' do
      SiteSetting.content_security_policy_collect_reports = true
      report_uri = parse(policy)['report-uri'].first
      expect(report_uri).to eq('http://test.localhost/csp_reports')

      SiteSetting.content_security_policy_collect_reports = false
      report_uri = parse(policy)['report-uri']
      expect(report_uri).to eq(nil)
    end
  end

  describe 'base-uri' do
    it 'is set to none' do
      base_uri = parse(policy)['base-uri']
      expect(base_uri).to eq(["'none'"])
    end
  end

  describe 'object-src' do
    it 'is set to none' do
      object_srcs = parse(policy)['object-src']
      expect(object_srcs).to eq(["'none'"])
    end
  end

  describe 'worker-src' do
    it 'has expected values' do
      worker_srcs = parse(policy)['worker-src']
      expect(worker_srcs).to eq(%w[
        'self'
        http://test.localhost/assets/
        http://test.localhost/brotli_asset/
        http://test.localhost/javascripts/
        http://test.localhost/plugins/
      ])
    end
  end

  describe 'script-src' do
    it 'always has self, logster, sidekiq, and assets' do
      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include(*%w[
        http://test.localhost/logs/
        http://test.localhost/sidekiq/
        http://test.localhost/mini-profiler-resources/
        http://test.localhost/assets/
        http://test.localhost/brotli_asset/
        http://test.localhost/extra-locales/
        http://test.localhost/highlight-js/
        http://test.localhost/javascripts/
        http://test.localhost/plugins/
        http://test.localhost/theme-javascripts/
        http://test.localhost/svg-sprite/
      ])
    end

    it 'includes "report-sample" when report collection is enabled' do
      SiteSetting.content_security_policy_collect_reports = true
      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include("'report-sample'")
    end

    context 'for Google Analytics' do
      before do
        SiteSetting.ga_universal_tracking_code = 'UA-12345678-9'
      end

      it 'allowlists Google Analytics v3 when integrated' do
        script_srcs = parse(policy)['script-src']
        expect(script_srcs).to include('https://www.google-analytics.com/analytics.js')
        expect(script_srcs).not_to include('https://www.googletagmanager.com/gtag/js')
      end

      it 'allowlists Google Analytics v4 when integrated' do
        SiteSetting.ga_version = 'v4_gtag'

        script_srcs = parse(policy)['script-src']
        expect(script_srcs).to include('https://www.google-analytics.com/analytics.js')
        expect(script_srcs).to include('https://www.googletagmanager.com/gtag/js')
      end
    end

    it 'allowlists Google Tag Manager when integrated' do
      SiteSetting.gtm_container_id = 'GTM-ABCDEF'

      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include('https://www.googletagmanager.com/gtm.js')
      expect(script_srcs.to_s).to include('nonce-')
    end

    it 'allowlists CDN assets when integrated' do
      set_cdn_url('https://cdn.com')

      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include(*%w[
        https://cdn.com/assets/
        https://cdn.com/brotli_asset/
        https://cdn.com/highlight-js/
        https://cdn.com/javascripts/
        https://cdn.com/plugins/
        https://cdn.com/theme-javascripts/
        http://test.localhost/extra-locales/
      ])

      global_setting(:s3_cdn_url, 'https://s3-cdn.com')

      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include(*%w[
        https://s3-cdn.com/assets/
        https://s3-cdn.com/brotli_asset/
        https://cdn.com/highlight-js/
        https://cdn.com/javascripts/
        https://cdn.com/plugins/
        https://cdn.com/theme-javascripts/
        http://test.localhost/extra-locales/
      ])
    end

    it 'adds subfolder to CDN assets' do
      set_cdn_url('https://cdn.com')
      set_subfolder('/forum')

      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include(*%w[
        https://cdn.com/forum/assets/
        https://cdn.com/forum/brotli_asset/
        https://cdn.com/forum/highlight-js/
        https://cdn.com/forum/javascripts/
        https://cdn.com/forum/plugins/
        https://cdn.com/forum/theme-javascripts/
        http://test.localhost/forum/extra-locales/
      ])

      global_setting(:s3_cdn_url, 'https://s3-cdn.com')

      script_srcs = parse(policy)['script-src']
      expect(script_srcs).to include(*%w[
        https://s3-cdn.com/assets/
        https://s3-cdn.com/brotli_asset/
        https://cdn.com/forum/highlight-js/
        https://cdn.com/forum/javascripts/
        https://cdn.com/forum/plugins/
        https://cdn.com/forum/theme-javascripts/
        http://test.localhost/forum/extra-locales/
      ])
    end
  end

  describe 'frame-ancestors' do
    context 'with content_security_policy_frame_ancestors enabled' do
      before do
        SiteSetting.content_security_policy_frame_ancestors = true
        Fabricate(:embeddable_host, host: 'https://a.org')
        Fabricate(:embeddable_host, host: 'https://b.org')
      end

      it 'always has self' do
        frame_ancestors = parse(policy)['frame-ancestors']
        expect(frame_ancestors).to include("'self'")
      end

      it 'includes all EmbeddableHost' do
        EmbeddableHost
        frame_ancestors = parse(policy)['frame-ancestors']
        expect(frame_ancestors).to include("https://a.org")
        expect(frame_ancestors).to include("https://b.org")
      end
    end

    context 'with content_security_policy_frame_ancestors disabled' do
      before do
        SiteSetting.content_security_policy_frame_ancestors = false
      end

      it 'does not set frame-ancestors' do
        frame_ancestors = parse(policy)['frame-ancestors']
        expect(frame_ancestors).to be_nil
      end
    end
  end

  it 'can be extended by plugins' do
    plugin = Class.new(Plugin::Instance) do
      attr_accessor :enabled
      def enabled?
        @enabled
      end
    end.new(nil, "#{Rails.root}/spec/fixtures/plugins/csp_extension/plugin.rb")

    plugin.activate!
    Discourse.plugins << plugin

    plugin.enabled = true
    expect(parse(policy)['script-src']).to include('https://from-plugin.com')
    expect(parse(policy)['object-src']).to include('https://test-stripping.com')
    expect(parse(policy)['object-src']).to_not include("'none'")

    plugin.enabled = false
    expect(parse(policy)['script-src']).to_not include('https://from-plugin.com')

    Discourse.plugins.pop
  end

  it 'only includes unsafe-inline for qunit paths' do
    expect(parse(policy(path_info: "/qunit"))['script-src']).to include("'unsafe-eval'")
    expect(parse(policy(path_info: "/wizard/qunit"))['script-src']).to include("'unsafe-eval'")
    expect(parse(policy(path_info: "/"))['script-src']).to_not include("'unsafe-eval'")
  end

  context "with a theme" do
    let!(:theme) {
      Fabricate(:theme).tap do |t|
        settings = <<~YML
          extend_content_security_policy:
            type: list
            default: 'script-src: from-theme.com'
        YML
        t.set_field(target: :settings, name: :yaml, value: settings)
        t.save!
      end
    }

    def theme_policy
      policy([theme.id])
    end

    it 'can be extended by themes' do
      policy # call this first to make sure further actions clear the cache

      expect(parse(policy)['script-src']).not_to include('from-theme.com')

      expect(parse(theme_policy)['script-src']).to include('from-theme.com')

      theme.update_setting(:extend_content_security_policy, "script-src: https://from-theme.net|worker-src: from-theme.com")
      theme.save!

      expect(parse(theme_policy)['script-src']).to_not include('from-theme.com')
      expect(parse(theme_policy)['script-src']).to include('https://from-theme.net')
      expect(parse(theme_policy)['worker-src']).to include('from-theme.com')

      theme.destroy!

      expect(parse(theme_policy)['script-src']).to_not include('https://from-theme.net')
      expect(parse(theme_policy)['worker-src']).to_not include('from-theme.com')
    end

    it 'can be extended by theme modifiers' do
      policy # call this first to make sure further actions clear the cache

      theme.theme_modifier_set.csp_extensions = ["script-src: https://from-theme-flag.script", "worker-src: from-theme-flag.worker"]
      theme.save!

      expect(parse(theme_policy)['script-src']).to include('https://from-theme-flag.script')
      expect(parse(theme_policy)['worker-src']).to include('from-theme-flag.worker')

      theme.destroy!

      expect(parse(theme_policy)['script-src']).to_not include('https://from-theme-flag.script')
      expect(parse(theme_policy)['worker-src']).to_not include('from-theme-flag.worker')
    end

    it 'is extended automatically when themes reference external scripts' do
      policy # call this first to make sure further actions clear the cache

      theme.set_field(target: :common, name: "header", value: <<~SCRIPT)
        <script src='https://example.com/myscript.js'></script>
        <script src='https://example.com/myscript2.js?with=query'></script>
        <script src='//example2.com/protocol-less-script.js'></script>
        <script src='domain-only.com'></script>
        <script>console.log('inline script')</script>
      SCRIPT

      theme.set_field(target: :desktop, name: "header", value: "")
      theme.save!

      expect(parse(theme_policy)['script-src']).to include('https://example.com/myscript.js')
      expect(parse(theme_policy)['script-src']).to include('https://example.com/myscript2.js')
      expect(parse(theme_policy)['script-src']).not_to include('?')
      expect(parse(theme_policy)['script-src']).to include('example2.com/protocol-less-script.js')
      expect(parse(theme_policy)['script-src']).not_to include('domain-only.com')
      expect(parse(theme_policy)['script-src']).not_to include(a_string_matching /^\/theme-javascripts/)

      theme.destroy!

      expect(parse(theme_policy)['script-src']).to_not include('https://example.com/myscript.js')
    end
  end

  it 'can be extended by site setting' do
    SiteSetting.content_security_policy_script_src = 'from-site-setting.com|from-site-setting.net'

    expect(parse(policy)['script-src']).to include('from-site-setting.com', 'from-site-setting.net')
  end

  def parse(csp_string)
    csp_string.split(';').map do |policy|
      directive, *sources = policy.split
      [directive, sources]
    end.to_h
  end

  def policy(theme_ids = [], path_info: "/")
    ContentSecurityPolicy.policy(theme_ids, path_info: path_info)
  end
end