[csp] Telemetry for csp configuration (#43223)

We collect the boolean configurations which can be derived by any
end-user of Kibana by making any HTTP request. Since the rules
configuration involves strings that can leak identifiable information,
we only collect whether the rules have been changed from their defaults.

x-pack/legacy/plugins/oss_telemetry/server/lib/collectors/csp/csp_collector.test.ts

@@ -0,0 +1,78 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import sinon from 'sinon';
+import { DEFAULT_CSP_RULES } from '../../../../../../../../src/legacy/server/csp';
+import {
+  getMockCallWithInternal,
+  getMockKbnServer,
+  getMockTaskFetch,
+} from '../../../../test_utils';
+import { createCspCollector } from './csp_collector';
+
+test('fetches whether strict mode is enabled', async () => {
+  const { collector, mockConfig } = setupCollector();
+
+  expect((await collector.fetch()).strict).toEqual(true);
+
+  mockConfig.get.withArgs('csp.strict').returns(false);
+  expect((await collector.fetch()).strict).toEqual(false);
+});
+
+test('fetches whether the legacy browser warning is enabled', async () => {
+  const { collector, mockConfig } = setupCollector();
+
+  expect((await collector.fetch()).warnLegacyBrowsers).toEqual(true);
+
+  mockConfig.get.withArgs('csp.warnLegacyBrowsers').returns(false);
+  expect((await collector.fetch()).warnLegacyBrowsers).toEqual(false);
+});
+
+test('fetches whether the csp rules have been changed or not', async () => {
+  const { collector, mockConfig } = setupCollector();
+
+  expect((await collector.fetch()).rulesChangedFromDefault).toEqual(false);
+
+  mockConfig.get.withArgs('csp.rules').returns(['not', 'default']);
+  expect((await collector.fetch()).rulesChangedFromDefault).toEqual(true);
+});
+
+test('does not include raw csp.rules under any property names', async () => {
+  const { collector } = setupCollector();
+
+  // It's important that we do not send the value of csp.rules here as it
+  // can be customized with values that can be identifiable to given
+  // installs, such as URLs
+  //
+  // We use a snapshot here to ensure csp.rules isn't finding its way into the
+  // payload under some new and unexpected variable name (e.g. cspRules).
+  expect(await collector.fetch()).toMatchInlineSnapshot(`
+    Object {
+      "rulesChangedFromDefault": false,
+      "strict": true,
+      "warnLegacyBrowsers": true,
+    }
+  `);
+});
+
+test('does not arbitrarily fetch other csp configurations (e.g. whitelist only)', async () => {
+  const { collector, mockConfig } = setupCollector();
+
+  mockConfig.get.withArgs('csp.foo').returns('bar');
+
+  expect(await collector.fetch()).not.toHaveProperty('foo');
+});
+
+function setupCollector() {
+  const mockConfig = { get: sinon.stub() };
+  mockConfig.get.withArgs('csp.rules').returns(DEFAULT_CSP_RULES);
+  mockConfig.get.withArgs('csp.strict').returns(true);
+  mockConfig.get.withArgs('csp.warnLegacyBrowsers').returns(true);
+
+  const mockKbnServer = getMockKbnServer(getMockCallWithInternal(), getMockTaskFetch(), mockConfig);
+
+  return { mockConfig, collector: createCspCollector(mockKbnServer) };
+}

x-pack/legacy/plugins/oss_telemetry/server/lib/collectors/csp/csp_collector.ts

@@ -0,0 +1,39 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import {
+  createCSPRuleString,
+  DEFAULT_CSP_RULES,
+} from '../../../../../../../../src/legacy/server/csp';
+import { HapiServer } from '../../../../';
+
+export function createCspCollector(server: HapiServer) {
+  return {
+    type: 'csp',
+    isReady: () => true,
+    async fetch() {
+      const config = server.config();
+
+      // It's important that we do not send the value of csp.rules here as it
+      // can be customized with values that can be identifiable to given
+      // installs, such as URLs
+      const defaultRulesString = createCSPRuleString([...DEFAULT_CSP_RULES]);
+      const actualRulesString = createCSPRuleString(config.get('csp.rules'));
+
+      return {
+        strict: config.get('csp.strict'),
+        warnLegacyBrowsers: config.get('csp.warnLegacyBrowsers'),
+        rulesChangedFromDefault: defaultRulesString !== actualRulesString,
+      };
+    },
+  };
+}
+
+export function registerCspCollector(server: HapiServer): void {
+  const { usage } = server;
+  const collector = usage.collectorSet.makeUsageCollector(createCspCollector(server));
+  usage.collectorSet.register(collector);
+}

x-pack/legacy/plugins/oss_telemetry/server/lib/collectors/csp/index.ts

@@ -0,0 +1,7 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+export { registerCspCollector } from './csp_collector';

x-pack/legacy/plugins/oss_telemetry/server/lib/collectors/index.ts

@@ -5,8 +5,10 @@
  */
 
 import { HapiServer } from '../../../';
+import { registerCspCollector } from './csp';
 import { registerVisualizationsCollector } from './visualizations/register_usage_collector';
 
 export function registerCollectors(server: HapiServer) {
   registerVisualizationsCollector(server);
+  registerCspCollector(server);
 }

x-pack/legacy/plugins/oss_telemetry/test_utils/index.ts

@@ -30,9 +30,16 @@ export const getMockTaskFetch = (docs: TaskInstance[] = defaultMockTaskDocs) =>
   return () => Promise.resolve({ docs });
 };
 
+export const getMockConfig = () => {
+  return {
+    get: () => '',
+  };
+};
+
 export const getMockKbnServer = (
   mockCallWithInternal = getMockCallWithInternal(),
-  mockTaskFetch = getMockTaskFetch()
+  mockTaskFetch = getMockTaskFetch(),
+  mockConfig = getMockConfig()
 ): HapiServer => ({
   plugins: {
     elasticsearch: {
@@ -53,6 +60,6 @@ export const getMockKbnServer = (
       register: () => undefined,
     },
   },
-  config: () => ({ get: () => '' }),
+  config: () => mockConfig,
   log: () => undefined,
 });