gecko-dev/security/sandbox/test/browser_bug1393259.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";

/*
 * This test validates that an OTF font installed in a directory not
 * accessible to content processes is rendered correctly by checking that
 * content displayed never uses the OS fallback font "LastResort". When
 * a content process renders a page with the fallback font, that is an
 * indication the content process failed to read or load the computed font.
 * The test uses a version of the Fira Sans font and depends on the font
 * not being already installed and enabled.
 */

ChromeUtils.import("resource://gre/modules/FileUtils.jsm");

const kPageURL =
  "http://example.com/browser/security/sandbox/test/bug1393259.html";

const environment = Cc["@mozilla.org/process/environment;1"]
                    .getService(Ci.nsIEnvironment);

const InspectorUtils = SpecialPowers.InspectorUtils;

// Parameters for running the python script that registers/unregisters fonts.
const kPythonPath = "/usr/bin/python";
const kFontInstallerPath = "browser/security/sandbox/test/mac_register_font.py";
const kUninstallFlag = "-u";
const kVerboseFlag = "-v";

// Where to find the font in the test environment.
const kRepoFontPath = "browser/security/sandbox/test/FiraSans-Regular.otf";

// Font name strings to check for.
const kLastResortFontName = "LastResort";
const kTestFontName = "Fira Sans";

// Home-relative path to install a private font. Where a private font is
// a font at a location not readable by content processes.
const kPrivateFontSubPath = "/FiraSans-Regular.otf";

add_task(async function() {
  await new Promise(resolve => waitForFocus(resolve, window));

  await BrowserTestUtils.withNewTab({
    gBrowser,
    url: kPageURL
  }, async function(aBrowser) {
    function runProcess(aCmd, aArgs, blocking = true) {
      let cmdFile = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
      cmdFile.initWithPath(aCmd);

      let process = Cc["@mozilla.org/process/util;1"]
                      .createInstance(Ci.nsIProcess);
      process.init(cmdFile);
      process.run(blocking, aArgs, aArgs.length);
      return process.exitValue;
    }

    // Register the font at path |fontPath| and wait
    // for the brower to detect the change.
    async function registerFont(fontPath) {
      let fontRegistered = getFontNotificationPromise();
      let exitCode = runProcess(kPythonPath, [kFontInstallerPath, kVerboseFlag,
                                              fontPath]);
      Assert.ok(exitCode == 0, "registering font" + fontPath);
      if (exitCode == 0) {
        // Wait for the font registration to be detected by the browser.
        await fontRegistered;
      }
    }

    // Unregister the font at path |fontPath|. If |waitForUnreg| is true,
    // don't wait for the browser to detect the change and don't use
    // the verbose arg for the unregister command.
    async function unregisterFont(fontPath, waitForUnreg = true) {
      let args = [kFontInstallerPath, kUninstallFlag];
      let fontUnregistered;

      if (waitForUnreg) {
        args.push(kVerboseFlag);
        fontUnregistered = getFontNotificationPromise();
      }

      let exitCode = runProcess(kPythonPath, args.concat(fontPath));
      if (waitForUnreg) {
        Assert.ok(exitCode == 0, "unregistering font" + fontPath);
        if (exitCode == 0) {
          await fontUnregistered;
        }
      }
    }

    // Pref "font.internaluseonly.changed" is updated when system
    // fonts change. We use it to wait for changes to be detected
    // in the browser.
    let prefBranch =
      Services.prefs.getBranch("font.internaluseonly.");

    // Returns a promise that resolves when the pref is changed
    let getFontNotificationPromise = () => new Promise(resolve => {
      let prefObserver = {
        QueryInterface: ChromeUtils.generateQI([Ci.nsIObserver]),
        observe() {
          prefBranch.removeObserver("changed", prefObserver);
          resolve();
        },
      };
      prefBranch.addObserver("changed", prefObserver);
    });

    let homeDir = Services.dirsvc.get("Home", Ci.nsIFile);
    let privateFontPath = homeDir.path + kPrivateFontSubPath;

    registerCleanupFunction(function() {
      unregisterFont(privateFontPath, /* waitForUnreg = */ false);
      runProcess("/bin/rm", [privateFontPath], /* blocking = */ false);
    });

    // Copy the font file to the private path.
    runProcess("/bin/cp", [kRepoFontPath, privateFontPath]);

    // Cleanup previous aborted tests.
    unregisterFont(privateFontPath, /* waitForUnreg = */ false);

    await registerFont(privateFontPath);

    // Get a list of fonts being used to display the web content.
    let fontList = await ContentTask.spawn(aBrowser, {}, async function() {
      let window = content.window.wrappedJSObject;
      let range = window.document.createRange();
      let contentDiv = window.document.getElementById("content");
      range.selectNode(contentDiv);
      let fonts = InspectorUtils.getUsedFontFaces(range);

      let fontList = [];
      for (let i = 0; i < fonts.length; i++) {
        fontList.push({name: fonts[i].name});
      }
      return fontList;
    });

    let lastResortFontUsed = false;
    let testFontUsed = false;

    for (let font of fontList) {
      // Did we fall back to the "LastResort" font?
      if (!lastResortFontUsed && font.name.includes(kLastResortFontName)) {
        lastResortFontUsed = true;
        continue;
      }
      // Did we render using our test font as expected?
      if (!testFontUsed && font.name.includes(kTestFontName)) {
        testFontUsed = true;
        continue;
      }
    }

    Assert.ok(!lastResortFontUsed,
      `The ${kLastResortFontName} fallback font was not used`);

    Assert.ok(testFontUsed,
      `The test font "${kTestFontName}" was used`);

    await unregisterFont(privateFontPath);
  });
});