Sys-audio and bluetooth - how safe?

[nexus]

Hi, I’m trying to make a final judgement on the functionality and the safety considerations of putting a bluetooth daemon inside of sys-audio in order to stream sound to an external bluetooth sink.

1. Is this a functional approach to getting your sound streamed? Are there any issues that come up that make it impractical or not-what-you-want?

2. What are the safety considerations of this? Assuming bluetooth is compromised how much of a risk are you taking? Does sys-audio only get data from other qubes or does it also offer an attack vector into them? Is the only fear that you might have someone listening over bluetooth to your audio?

3. What are the alternative ways to stream audio to an external bluetooth device? I imagine that you could 1) install a bluetooth daemon inside of a specific qube and stream from that and 2) install a bluetooth daemon inside of some sys-qube, would that be different somehow than using sys-audio? What are the considerations?

Thanks.

[Suspicious_Actions]

Interessting question.

Sadly i am not too deep into the sound stuff to give any educated guess for the first two questions, but will read the answer here as i am interested in that too.

I wanted to state that the safest way to transmit audio over bluetooth is probably to use a dedicated hardware bluetooth transmitter attached to your audio out.

[fsflover]

@nexus

What are the safety considerations of this? Assuming bluetooth is compromised how much of a risk are you taking?

Here is some hint from the developers:

Even Bluetooth audio devices (like headphones) could finally be used securely, without exposing the whole system to attack.

[enmus]

@nexus

Is this a functional approach to getting your sound streamed?

Yes, as far as I see it.

@nexus

Are there any issues that come up that make it impractical or not-what-you-want?

Not that I’m aware of

@nexus

What are the safety considerations of this?

Usual regarding bluetooth.

@nexus

Assuming bluetooth is compromised how much of a risk are you taking?

It depends on your neighbors, I’d say.

@nexus

Does sys-audio … offer an attack vector into them?

As far as I see it not bigger than any audio in dom0 to any other qube.

@nexus

Is the only fear that you might have someone listening over bluetooth to your audio?

It depends on your neighbors, I guess.

@nexus

What are the alternative ways to stream audio to an external bluetooth device?

@nexus

I imagine that you could 1) install a bluetooth daemon inside of a specific qube and stream from that and

Sys-audio?
The whole point of sys-audio is to remove as much as possible hardware from dom0 thus further reducing attack surface.

If you decide to use bluetooth, it’s irrelevant to what app qube you would attach it, but at least make it offline. You saved dom0 anyway.

Maybe something of this would give you an idea

Guide on using an USB audio device with Qubes 4.1

I am not good at writing guides, but will do my best. The point of this guide-for-noobs-like-me is, by using the tips from a link in the OP to set up a separate sys-audio-like domain for USB audio cards in Qubes OS 4.1, so to avoid the need to attach-detach USB card from qube to qube when needed. Instead, a single qube will be set, to which the USB card and microphone will be permanently attached, so all other qubes could use USB card without the need of direct attach. I have named the domain…

Unable to passthrough audio device to sys-audio

I am trying to create functional sys-audio according to this post since there are no official manuals so far. running qvm-pci: dom0:00_1b.0 Audio device: Intel Corporation 7 Series/C216 Chipset Family High Definition Audio Controller sys-audio (no-strict-reset=True) I didn’t change automatically created /etc/qubes/policy.d/50-sys-audio.policy file, for the same reason and since I am not familiar with it’s meaning, so it’s content is

Summary

admin.Events * sys-audio sys-au…

[nexus]

The usual safety considerations in regards to bluetooth is that if someone is able to compromise bluetooth then they’ll be able to own your system. I’m under the impression that even if someone was to compromise bluetooth if you use it inside of sys-audio there is no channel that lets sys-audio change other qubes and as such you’re safe except for perhaps having your sound listened to if you assume Qubes does not have an unintentional leak.
To me that sounds like these safety considerations are a lot safer than the usual bluetooth ones. Am I misunderstanding something?