Does WebUSB is supported by permissions infrastructure?

Question

WebUSB API documentation introduces new powerful feature with name "usb" to permissions infrastructure (https://wicg.github.io/webusb/#permission-api). But when I try to use permissions api to query permissions for "usb":

navigator.permissions.query({name:'usb'})

I got error:

TypeError: Failed to execute 'query' on 'Permissions': The provided value 'usb' is not a valid enum value of type PermissionName.

I use Chrome Version 83.0.4103.97 (Official Build) (64-bit) on Ubuntu. My first question:

1. Does permissions api support "usb" feature? If yes, what I do wrong in upper code?

Specification on WebUSB defines where to store allowed devices, but it again offered to use permissions infrastructure as I understood (https://wicg.github.io/webusb/#request-the-usb-permission). My second question:

2. If permissions api not yet support "usb" feature, where/how allowed devices are stored in browser? Can I programmatically get access to this storage?

3. Can website request user to allow permissions to group of devices (in my case by vid+pid) which not only connected right now, but also can be connected in future? In other words, I want to ask user "Please, let me work with usb devices (with this vid+pid) which you connect in a future, because I don't want to bore you with permission question every time you connect new device of particular type".

Answer 1

1. Does permissions api support "usb" feature? If yes, what I do wrong in upper code?

No. While the Permissions API integration defined in the specification is implemented in Chromium-based browsers it is not exposed through the Permissions API's query() method. This is tracked by issue 638721 but has not been a priority given the available alternatives.

2. If permissions api not yet support "usb" feature, where/how allowed devices are stored in browser? Can I programmatically get access to this storage?

Permissions are stored in the browser's user preferences file and internal data structures which are not directly accessible to Javascript. The only way these permissions are currently exposed are through the settings UI (chrome://settings/content/usbDevices) and the navigator.usb.getDevices() method, which only returns allowed devices if they are currently connected.

3. Can website request user to allow permissions to group of devices (in my case by vid+pid) which not only connected right now, but also can be connected in future? In other words, I want to ask user "Please, let me work with usb devices (with this vid+pid) which you connect in a future, because I don't want to bore you with permission question every time you connect new device of particular type".

No. It is important to the security design of the API that the user make the decision based on the devices currently connected rather than a hypothetical future device.

For enterprise managed devices the WebUsbAllowDevicesForUrls policy allows an administrator to make this type of decision on behalf of their users.