core(csp-xss): csp evaluator npm module

lighthouse-core/audits/csp-xss.js

@@ -9,9 +9,7 @@ const Audit = require('./audit.js');
 const MainResource = require('../computed/main-resource.js');
 const i18n = require('../lib/i18n/i18n.js');
 const {
-  evaluateRawCspForFailures,
-  evaluateRawCspForWarnings,
-  evaluateRawCspForSyntax,
+  evaluateRawCspsForXss,
   getTranslatedDescription,
 } = require('../lib/csp-evaluator.js');
 
@@ -29,8 +27,6 @@ const UIStrings = {
   /** Message shown when one or more CSPs are defined in a <meta> tag. Shown in a table with a list of other CSP bypasses and warnings. "CSP" stands for "Content Security Policy". "CSP" and "HTTP" do not need to be translated. */
   metaTagMessage: 'The page contains a CSP defined in a <meta> tag. ' +
     'Consider defining the CSP in an HTTP header if you can.',
-  /** Message shown when a CSP has no syntax errors. Shown in a table with a list of other CSP bypasses and warnings. "CSP" stands for "Content Security Policy". */
-  noSyntaxErrors: 'No syntax errors.',
   /** Label for a column in a data table; entries will be a directive of a CSP. "CSP" stands for "Content Security Policy". */
   columnDirective: 'Directive',
 };
@@ -88,20 +84,17 @@ class CspXss extends Audit {
   }
 
   /**
+   * @param {import('../lib/csp-evaluator').Finding[][]} syntaxFindings
    * @param {string[]} rawCsps
    * @return {LH.Audit.Details.TableItem[]}
    */
-  static collectSyntaxResults(rawCsps) {
+  static constructSyntaxResults(syntaxFindings, rawCsps) {
     /** @type {LH.Audit.Details.TableItem[]} */
     const results = [];
 
-    const syntaxFindingsByCsp = evaluateRawCspForSyntax(rawCsps);
-    for (let i = 0; i < rawCsps.length; ++i) {
-      const items = syntaxFindingsByCsp[i].map(this.findingToTableItem);
-      if (!items.length) {
-        items.push({description: str_(UIStrings.noSyntaxErrors)});
-      }
-
+    for (let i = 0; i < syntaxFindings.length; ++i) {
+      const items = syntaxFindings[i].map(this.findingToTableItem);
+      if (!items.length) continue;
       results.push({
         description: {
           type: 'code',
@@ -117,27 +110,6 @@ class CspXss extends Audit {
     return results;
   }
 
-  /**
-   * @param {string[]} rawCsps
-   * @return {LH.Audit.Details.TableItem[]}
-   */
-  static collectBypassResults(rawCsps) {
-    const findings = evaluateRawCspForFailures(rawCsps);
-    return findings.map(this.findingToTableItem);
-  }
-
-  /**
-   * @param {string[]} rawCsps
-   * @return {LH.Audit.Details.TableItem[]}
-   */
-  static collectWarningResults(rawCsps) {
-    const findings = evaluateRawCspForWarnings(rawCsps);
-    const results = [
-      ...findings.map(this.findingToTableItem),
-    ];
-    return results;
-  }
-
   /**
    * @param {LH.Artifacts} artifacts
    * @param {LH.Audit.Context} context
@@ -155,17 +127,19 @@ class CspXss extends Audit {
     }
 
     // TODO: Add severity icons for bypasses and warnings.
-    const bypasses = this.collectBypassResults(rawCsps);
-    const warnings = this.collectWarningResults(rawCsps);
-    const syntax = this.collectSyntaxResults(rawCsps);
+    const {bypasses, warnings, syntax} = evaluateRawCspsForXss(rawCsps);
+
+    const results = [
+      ...this.constructSyntaxResults(syntax, rawCsps),
+      ...bypasses.map(this.findingToTableItem),
+      ...warnings.map(this.findingToTableItem),
+    ];
 
     // Add extra warning for a CSP defined in a meta tag.
     if (cspMetaTags.length) {
-      warnings.push({description: str_(UIStrings.metaTagMessage), directive: undefined});
+      results.push({description: str_(UIStrings.metaTagMessage), directive: undefined});
     }
 
-    const results = [...syntax, ...bypasses, ...warnings];
-
     /** @type {LH.Audit.Details.Table['headings']} */
     const headings = [
       /* eslint-disable max-len */

lighthouse-core/lib/csp-evaluator.js

@@ -5,32 +5,25 @@
  */
 'use strict';
 
-/**
- * @typedef Finding
- * @property {number} type
- * @property {string} description
- * @property {number} severity Severity value 0-100 where 0 is the most severe.
- * @property {string} directive The directive the finding applies to.
- * @property {string|undefined} value Keyword if the finding applies to one.
- */
+/** @typedef {import('csp_evaluator/finding').Finding} Finding */
 
-const log = require('lighthouse-logger');
-const i18n = require('../lib/i18n/i18n.js');
 const {
-  Parser,
-  Type,
-  Directive,
   evaluateForFailure,
   evaluateForSyntaxErrors,
   evaluateForWarnings,
-} = require('../../third-party/csp-evaluator/optimized_binary.js');
+} = require('csp_evaluator/dist/lighthouse/lighthouse_checks.js');
+const {Type} = require('csp_evaluator/dist/finding.js');
+const {CspParser} = require('csp_evaluator/dist/parser.js');
+const {Directive} = require('csp_evaluator/dist/csp.js');
+
+const log = require('lighthouse-logger');
+const i18n = require('../lib/i18n/i18n.js');
 
 const UIStrings = {
   /** Message shown when a CSP does not have a base-uri directive. Shown in a table with a list of other CSP vulnerabilities and suggestions. "CSP" stands for "Content Security Policy". "base-uri", "'none'", and "'self'" do not need to be translated. */
-  missingBaseUri: 'Missing base-uri allows the injection of <base> tags. ' +
-    'They can be used to set the base URL for all relative (script) ' +
-    'URLs to an attacker controlled domain. ' +
-    'Can you set it to \'none\' or \'self\'?',
+  missingBaseUri: 'Missing base-uri allows injected <base> tags to set the base URL for all ' +
+    'relative URLs (e.g. scripts) to an attacker controlled domain. ' +
+    'Consider setting base-uri to \'none\' or \'self\'.',
   /** Message shown when a CSP does not have a script-src directive. Shown in a table with a list of other CSP vulnerabilities and suggestions. "CSP" stands for "Content Security Policy". "script-src" does not need to be translated. */
   missingScriptSrc: 'script-src directive is missing. ' +
     'This can allow the execution of unsafe scripts.',
@@ -140,37 +133,27 @@ function getTranslatedDescription(finding) {
 }
 
 /**
- * Evaluator looks at all CSPs together to find bypasses.
- * Multiple CSPs can form a strict policy even if they would be bypassable on their own.
- * @param {string[]} rawCsps
- * @return {Finding[]}
- */
-function evaluateRawCspForFailures(rawCsps) {
-  return evaluateForFailure(rawCsps.map(c => new Parser(c).csp));
-}
-
-/**
- * Evaluator looks at all CSPs together to find warnings.
- * Multiple CSPs can form a policy without warnings even if they would have warnings on their own.
- * @param {string[]} rawCsps
- * @return {Finding[]}
+ * @param {string} rawCsp
  */
-function evaluateRawCspForWarnings(rawCsps) {
-  return evaluateForWarnings(rawCsps.map(c => new Parser(c).csp));
+function parseCsp(rawCsp) {
+  return new CspParser(rawCsp).csp;
 }
 
 /**
  * @param {string[]} rawCsps
- * @return {Finding[][]} Entries are a list of findings corresponding to the CSP at the same index in `rawCsps`.
+ * @return {{bypasses: Finding[], warnings: Finding[], syntax: Finding[][]}}
  */
-function evaluateRawCspForSyntax(rawCsps) {
-  return evaluateForSyntaxErrors(rawCsps.map(c => new Parser(c).csp));
+function evaluateRawCspsForXss(rawCsps) {
+  const parsedCsps = rawCsps.map(parseCsp);
+  const bypasses = evaluateForFailure(parsedCsps);
+  const warnings = evaluateForWarnings(parsedCsps);
+  const syntax = evaluateForSyntaxErrors(parsedCsps);
+  return {bypasses, warnings, syntax};
 }
 
 module.exports = {
-  evaluateRawCspForFailures,
-  evaluateRawCspForWarnings,
-  evaluateRawCspForSyntax,
   getTranslatedDescription,
+  evaluateRawCspsForXss,
+  parseCsp,
   UIStrings,
 };