Re: USB HID devices not linked to RNG

On Mon, Sep 7, 2015 at 2:09 PM, Stephan Mueller [off-list ref] wrote:

Am Montag, 7. September 2015, 15:07:47 schrieb Mike Mestnik:

Hi Mike,

quoted

This is just an off the wall guess.  Wouldn't such entropy already be
collected at a lower level, like raw usb traffic?

The RNG collects data from interrupts (that also covers normal PS/2 mice and
keyboards), block devices and HID (it hooks itself into the input layer).

So, raw USB traffic is not a source of entropy other than for the interrupts
the base PCI traffic would generate.

What I am wondering: isn't the USB mouse/keyboard support hooking into the
kernel's input layer?

All input devices add randomness, however I think for mouse
add_input_randomness() will drop majority of events since they are
likely have the same value (well, depends on which direction you are
moving the mouse)...

-- 
Dmitry