Librem 15v4 first impressions

[kieran]

@whistler

Hopefully the plugin mic on Librem 14 will be wired to the same mechanical kill switch as the environmental mic. It’s architecturally obvious but easily forgotten.

Not forgotten though:

Blog Post: Librem 14 Adds Microphone Kill Switch Enhancements

Last week I announced that the Librem 14 would feature a special “kill switch” of sorts on the motherboard that would write-protect the BIOS and EC chips. I’m pleased to announce another enhancement that will be in the Librem 14: the microphone kill switch will also kill microphones connected through the headphone jack . Check out the full post here:

@Freedom_Right

You could toggle the Hardware Kill Switch for WiFi during startup for preventing a similar scenario.

I don’t think that works. If the HKS works as advertised then the WiFi will be dead as a dodo. So you can’t send it any commands e.g. to override the MAC address. As soon as you flip the HKS, and give power to the WiFi, it could in theory leak its MAC address.

So as far as I can see, three safe options are:

• the WiFi card has non-volatile storage for an overridden MAC address that can be rewritten many thousands of times
• the WiFi card guarantees not to transmit anything after power on until the operating system has had a chance to configure a random MAC address - but as noone controls the firmware of the WiFi card it would be difficult to accept such a guarantee
• the WiFi card powers up with no MAC address (let’s say 00:00:00:00:00:00) and simply doesn’t have a realistic address to leak until the operating system sets the MAC address - but the WiFi card does provide some means of at least supplying to the operating system (at least) the top three bytes of the MAC address.