[systemd-devel] What information does machine-id leak?

[Zbigniew Jędrzejewski-Szmek]

On Fri, Jan 20, 2017 at 02:54:30PM -0500, Bryan Quigley wrote:
> But what information is it carrying that is private?  If it's just the
> best way to identify a machine, that's really what I'm after.

machine-id is used to seed the identification of the machine in
different contexts (by hashing the machine-id with some application
specific seed). If you know the raw machine id, you can generate the
identifier for all contexts. If you want to preserve privacy
(in particular by making tracking across contexts harder), you cannot
use the raw machine-id.

> Here are two of my uses (all in debugging/troubleshooting purposes):
> * Sosreport captures logs/other information and currently captures the
> dbus machine-id (which this is) and the whoopsie-id
> * currently if you have the whoopsie-id you can lookup crashreports*
> on the Ubuntu Error tracker.
> 
> Neither use is app specific,
They both are. That's exactly what "application specific" means.

Zbyszek