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so, a lot of people I know have a severely negative view of WebUSB. that view is, mostly, justified. I think it is only more interesting then that I see the GrapheneOS flashing tool--yes, flashing stuff via the browser--as net beneficial

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An experimental version of our web-based installer for GrapheneOS is now available: grapheneos.org/install/web This can be used from browsers with WebUSB support. Most Chromium-based browsers are supported including Chrome, Edge and Brave. No need to run any additional software.

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it's beneficial because flashing is hard and most people rightfully don't want learn how fastboot, adb, etc work, and seek out convenience. they'll find it either with the first party, GrapheneOS, or a potentially malicious or negligent third party. here, WebUSB is harm reduction

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I'm not sure if WebUSB could have been designed in a way that makes harm negligible. I know that it could have been designed to minimize potential harm, and it clearly wasn't (Chrome just lets you do ~anything to ~any device), and I find that unfortunate.

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now that I re-read what I wrote above it sounds way more pessimistic than I intended, so let me clarify that:

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Replying to @taviso @analogist_net and @XMPPwocky

yes. I agree that it's often far better, too. I just think it doesn't go far enough! basically, I want WebUSB to be more like WebAssembly: not only merely isolate previously privileged code, but advance state of the art beyond that, like WASI does with the ObjCap stuff

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Brian Mastenbrook

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dumb question, do you know how Chrome handles elevation for WebUSB? is it once only, once per origin, silently handled by a privileged helper, or just not done at all?

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I've never used WebUSB with Chrome on Windows but lemme just spin up a VM because I conveniently have a WebUSB native device on my desk

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... it... doesn't work on Windows

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As far as I can tell, it uses the normal drivers for devices instead of a special one for WebUSB, so you need a working driver for it.

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which makes sense really, it would be pretty concerning if it started elevating itself and self-signing INFs

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It also means it depends on installing the same fastboot udev rules as usual on Linux which annoys me. I had to add that back to grapheneos.org/install/web since I'd deleted it when I copied the CLI installation guide there expecting that it wasn't going to be needed.

GrapheneOS web installer

Web-based installer for GrapheneOS, a security and privacy focused mobile OS with Android app compatibility.

3:56 AM · Jan 25, 2021Twitter Web App

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it would be *much* more concerning if it had a SUID binary that can talk to udev.

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Yeah, but originally I expected that WebUSB was a special thing that would use a generic WebUSB driver. I didn't realize it was just normal USB.

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It actually bubbles up a proper permission denied error to JavaScript which we end up displaying so at least there's a reasonable chance of figuring out why a user is getting the error.

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