AudioContext, HTMLMediaElement, and MediaStream provide currentTime to content scripts

The worst offender is probably AudioContext, where you can get the current time thus:

var audioContext = new AudioContext();
audioContext.currentTime;

Similarly, HTMLVideoElement.currentTime, HTMLAudioElement.currentTime, and CanvasCaptureMediaStream.currentTime can each be used as a time source with resolution better than 10 ms.

added TorBrowserTeam201606R component::applications/tor browser owner::tbb-team priority::medium resolution::fixed severity::normal status::closed type::defect labels

Here is a branch with two patches.

https://github.com/arthuredelstein/tor-browser/commits/19193

b91f47cce42a2e048f970a18710f9c15672a6cfc is a fixup for our #1517 (moved) patch that rounds the values returned by the currentTime attributes mentioned above.

936cadcc8dd2b0e6784be69cabe44880e36839b0 provides regression tests for all time sources we are rounding in the old and new patches.

Trac:
Status: new to needs_review
Keywords: TorBrowserTeam201605 deleted, TorBrowserTeam201605R added
Description: The worst offender is probably AudioContext, where you can get the current time thus:

var audioContext = new AudioContext();
audioContext.currentTime;

Similarly, HTMLVideoElement.currentTime, HTMLAudioElement.currentTime, and CanvasCaptureMediaStream.currentTime can be used as a time source with resolution better than 10 ms.

to

The worst offender is probably AudioContext, where you can get the current time thus:

var audioContext = new AudioContext();
audioContext.currentTime;

Similarly, HTMLVideoElement.currentTime, HTMLAudioElement.currentTime, and CanvasCaptureMediaStream.currentTime can each be used as a time source with resolution better than 10 ms.

Looks good to me.

Trac:
Cc: N/A to mcs, brade

Moving reviews to June

Trac:
Keywords: N/A deleted, TorBrowserTeam201606 added

Trac:
Keywords: TorBrowserTeam201605R deleted, TorBrowserTeam201606R added

Trac:
Keywords: TorBrowserTeam201606 deleted, N/A added

For the regression test patch (936cadcc8dd2b0e6784be69cabe44880e36839b0), the test code references silence.ogg but the patch adds a file named audio.ogg. Shouldn't they match?

The currentTime rounding patch (b91f47cce42a2e048f970a18710f9c15672a6cfc) looks good.

I tried to run the regression tests myself, but mach mochitest is not cooperating at the moment (I think this is due to Mac OS 10.11 Python differences; it is definitely not related to the tests themselves).

Replying to mcs:

I tried to run the regression tests myself, but mach mochitest is not cooperating at the moment (I think this is due to Mac OS 10.11 Python differences; it is definitely not related to the tests themselves).

OK, I was able to run tbb-tests/test_tor_bug1517.html on a different system and it worked correctly. I guess the test does not care about the silence.ogg vs. audio.ogg difference (but it should probably be fixed).

Replying to mcs:

Replying to mcs:

I tried to run the regression tests myself, but mach mochitest is not cooperating at the moment (I think this is due to Mac OS 10.11 Python differences; it is definitely not related to the tests themselves).

OK, I was able to run tbb-tests/test_tor_bug1517.html on a different system and it worked correctly. I guess the test does not care about the silence.ogg vs. audio.ogg difference (but it should probably be fixed).

Thanks for catching that mistake. I've corrected it here:

https://github.com/arthuredelstein/tor-browser/commits/19193+1

Fixed on tor-browser-45.2.0esr-6.5-1 with commit 49d0c6389eea055e94a8fb492bd95de56b9111a4 and b60b8871fa08feaaca24bcf6dff43df0cd1c5f29, thanks.

Trac:
Resolution: N/A to fixed
Status: needs_review to closed

closed

moved to tpo/applications/tor-browser#19193 (closed)