Closed palemieux closed 4 years ago
I've added this to the agenda for this week's call at w3c/ttwg#118. I believe the main outstanding questions we need to resolve, from this pull request, are:
condition
attribute, as per https://github.com/w3c/ttml2/pull/1203#discussion_r411271787 For the discussion on Thursday, my hope is that we can agree to change "Font Matching" to "Font Detection" as per Nick's comment.
I also hope we can get to agreement on whether the use of the condition
attribute provides any further ability to detect fonts. If we agree that it does not, then I will be happy to proceed with the current pull request. Then, consequently, I would like to know if the media queries available via the condition
attribute are considered a fingerprinting risk by PING. If not, then no further action need be taken. However if they are, then I would like to learn more about this, since it seems to me that exactly the same risk must exist in CSS, and therefore there may be some off the shelf potential mitigations available.
More information about the potential concern: the condition
attribute supports queries including media queries. All the external resource elements, audio
, image
, source
etc support this condition
attribute. Therefore it would be possible, while processing a TTML2 document, to request a URL from a remote origin based on the result of a media query, thus providing information to that origin. This is effectively the same functionality as CSS Media Queries provides – see https://drafts.csswg.org/mediaqueries-4/#priv-sec and https://github.com/w3c/csswg-drafts/issues/3488 for example. The CSS3 Media Query Rec at https://www.w3.org/TR/css3-mediaqueries/ from 2012 does not include any security and privacy section.
The Timed Text Working Group just discussed Add consideration for font fingerprinting w3c/ttml2#1203
, and agreed to the following:
RESOLUTION: Rename "Font Matching" to "Font Detection".
RESOLUTION: Detections based on condition attribute need not be factored into this pull request.
@samuelweiler @npdoty The TTWG has consensus to merge this PR. Are you in agreement that it resolves the issue to the best that we can get to at this stage? This does not prejudice us against making more normative statements in future editions, should we get agreement to do so.
Per https://github.com/w3c/ttml2/pull/1203#issuecomment-638923838 (see last sentence), we have approvals and consensus for merging.
Per #1203 (comment) (see last sentence), we have approvals and consensus for merging.
@skynavga That was a TTWG resolution, but in https://github.com/w3c/ttml2/pull/1203#issuecomment-638984684 I asked for the non-TTWG members who raised/commented on the issue for their view, with the intent of not merging before we had confirmation. If there are further comments we may now need to open a new pull request and review cycle: I had been hoping to avoid that; it may still not be needed of course.
@samuelweiler @npdoty The TTWG has consensus to merge this PR. Are you in agreement that it resolves the issue to the best that we can get to at this stage? This does not prejudice us against making more normative statements in future editions, should we get agreement to do so.
No. As in https://github.com/w3c/ttml2/pull/1203#discussion_r438418061, I think a normative mitigation is in order.
Closes #1202