Bug 1743524 don't expose speaker device info after getUserMedia({audio: true, fake: true}) r=jib

Differential Revision: https://phabricator.services.mozilla.com/D132434
2021-12-01 21:53:32 +00:00 · 2021-12-01 21:53:32 +00:00 · a775058a48
--- a/dom/media/MediaDevices.cpp
+++ b/dom/media/MediaDevices.cpp
@ -93,11 +93,13 @@ already_AddRefed<Promise> MediaDevices::GetUserMedia(
      }
    }
  }
+  bool haveFake = aConstraints.mFake.WasPassed() && aConstraints.mFake.Value();
  const OwningBooleanOrMediaTrackConstraints& audio = aConstraints.mAudio;
  bool isMicrophone =
-      audio.IsBoolean()
-          ? audio.GetAsBoolean()
-          : !audio.GetAsMediaTrackConstraints().mMediaSource.WasPassed();
+      !haveFake &&
+      (audio.IsBoolean()
+           ? audio.GetAsBoolean()
+           : !audio.GetAsMediaTrackConstraints().mMediaSource.WasPassed());
  RefPtr<MediaDevices> self(this);
  MediaManager::Get()
      ->GetUserMedia(owner, aConstraints, aCallerType)
--- a/dom/media/webrtc/tests/mochitests/head.js
+++ b/dom/media/webrtc/tests/mochitests/head.js
@ -418,6 +418,15 @@ function pushPrefs(...p) {
  return SpecialPowers.pushPrefEnv({ set: p });
 }

+async function withPrefs(prefs, func) {
+  await SpecialPowers.pushPrefEnv({ set: prefs });
+  try {
+    return await func();
+  } finally {
+    await SpecialPowers.popPrefEnv();
+  }
+}
+
 function setupEnvironment() {
  var defaultMochitestPrefs = {
    set: [
--- a/dom/media/webrtc/tests/mochitests/mochitest.ini
+++ b/dom/media/webrtc/tests/mochitests/mochitest.ini
@ -61,6 +61,7 @@ scheme=http
 [test_enumerateDevices.html]
 [test_enumerateDevices_navigation.html]
 skip-if = true # Disabled because it is a racy test and causes timeouts, see bug 1650932
+[test_enumerateDevices_getUserMediaFake.html]
 [test_groupId.html]
 [test_setSinkId.html]
 skip-if =
--- a/dom/media/webrtc/tests/mochitests/test_enumerateDevices_getUserMediaFake.html
+++ b/dom/media/webrtc/tests/mochitests/test_enumerateDevices_getUserMediaFake.html
@ -0,0 +1,75 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <meta charset="utf-8">
+  <script src="mediaStreamPlayback.js"></script>
+</head>
+<body>
+  <script>
+"use strict";
+
+createHTML({
+  title: "Test enumerateDevices() after fake getUserMedia()",
+  bug: "1743524"
+});
+
+runTest(async () => {
+  await pushPrefs(
+    ["media.setsinkid.enabled", true],
+    // This test uses real devices because fake devices are not grouped with
+    // audiooutput devices.
+    ["media.navigator.streams.fake", false],
+    // Non empty media.audio_loopback_dev would disable fake:true for streams
+    // returned from getUserMedia().
+    ["media.audio_loopback_dev", ""]);
+  const devices = navigator.mediaDevices;
+  {
+    // `fake:true` means that getUserMedia() resolves without any permission
+    // check, and so this should not be sufficient to expose real device info.
+    const stream = await devices.getUserMedia({ audio: true, fake: true });
+    // permission.disabled exposes labels - bug 1528042
+    const list = await withPrefs(
+      [["media.navigator.permission.disabled", false]],
+      async () => devices.enumerateDevices());
+    stream.getTracks()[0].stop();
+    const labeledDevices = list.filter(({label}) => label != "");
+    is(labeledDevices.length, 0, "number of labeled devices after fake gUM");
+    const outputDevices = list.filter(({kind}) => kind == "audiooutput");
+    is(outputDevices.length, 0, "number of output devices after fake gUM");
+  }
+  {
+    // Check without `fake:true` to verify assumptions about existing devices.
+    const streamPromise = devices.getUserMedia({ audio: true });
+    if (navigator.userAgent.includes("Mac OS X")) {
+      let rejection = "resolved";
+      try {
+        await streamPromise;
+      } catch (e) {
+        rejection = e.name;
+      }
+      todo_isnot(rejection, "NotFoundError",
+                 "Expecting no real audioinput device on Mac.");
+      return;
+    }
+    const stream = await streamPromise;
+    {
+      const list = await devices.enumerateDevices();
+      // input labels disappear when the track is stopped - bug 1528042
+      const unlabeledAudioDevices =
+            list.filter(({ kind, label }) => {
+              return kind != "videoinput" && label == ""
+            });
+      is(unlabeledAudioDevices.length, 0,
+         "number of unlabeled audio devices after real gUM");
+    }
+    stream.getTracks()[0].stop();
+    const list = await devices.enumerateDevices();
+    const outputDevices = list.filter(({ kind, label }) => {
+      return kind == "audiooutput" && label != "";
+    });
+    isnot(outputDevices.length, 0, "number of output devices after real gUM");
+  }
+});
+  </script>
+</body>
+</html>