[mediacapture-main] new getUserMedia language mandates collateral grants.

jan-ivar has just created a new issue for 
https://github.com/w3c/mediacapture-main:

== new getUserMedia language mandates collateral grants. ==
A 
[commit](https://github.com/w3c/mediacapture-main/commit/bbdee2433051107e597a4fbd277b6d619113ac54)
 from a month ago unilaterally changed the [getUserMedia 
algorithm](http://w3c.github.io/mediacapture-main/getusermedia.html#dom-mediadevices-getusermedia)'s
 step 7:
> [Request 
permission](http://w3c.github.io/mediacapture-main/getusermedia.html#request-permission)
 for use of the devices, while considering all devices attached to a 
`live` MediaStreamTrack to have permission status "granted", resulting
 in a set of provided media.

Putting aside https://github.com/w3c/mediacapture-main/issues/350, 
this mandates that UAs grant access to a camera if the site already 
has access to a microphone or a different camera. In essence, this 
makes any grant of a single device into a grant of all devices, a 
collateral grant.

Some browsers, like Chrome, already implement collateral grants by 
default (ask for anything once, and you have access to everything all 
the time). That's even a persistent collateral grant.

Other browsers, like Firefox, however, quite narrowly restricts grants
 to individual requests by default (unless the user explicitly chooses
 "Always Allow"). By restricting grants to individual requests, 
Firefox users effectively also restrict grants to specific devices (as
 long as they don't choose "Always Allow").

For instance, this means that in Firefox, users can grant permission 
to their microphone, but deny permission to their camera, and still 
hopefully participate in a conference call as an audio-only 
participant.
 
With this new language, it is not possible for Firefox to maintain or 
contemplate per-device permission.

The spec here is impinging on individual browser's permission models, 
and this change has apparently had no discussion.

Please view or discuss this issue at 
https://github.com/w3c/mediacapture-main/issues/355 using your GitHub 
account

Received on Friday, 29 April 2016 20:08:25 UTC