Re: [PATCH v4 12/13] bluetooth/smp: ensure RNG is properly seeded before ECDH use

From: Jason A. Donenfeld
Date: Thu Jun 08 2017 - 13:34:11 EST


On Thu, Jun 8, 2017 at 7:05 PM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote:
> on a powered down controller, you can not do any crypto. SMP is only during a connection and the RPAs are only generated when needed. So yes, doing this once in hci_power_on is plenty. However we might want to limit this to LE capable controllers since for BR/EDR only controllers this is not needed. For A2MP I need to check that we need the random numbers seeded there. However this hidden behind the high speed feature.

Okay so it sounds like certain controllers will use this and certain
won't, and so it might be slightly complicated to follow the mouse
through the tube ideally. In that case, I'd recommend continuing with
this current patchset, which just adds the wait (which is a no-op if
it's already seeded) close to the actual call sites.

Can you review that patch and give your Signed-off-by if it looks good?

Jason