Re: [PATCH] arm: re-randomize rng-seed on reboot

[Jason A. Donenfeld]

On Thu, Sep 29, 2022 at 10:57:22PM +0200, Jason A. Donenfeld via wrote:
> Hi Peter,
> 
> On Tue, Sep 27, 2022 at 06:07:42PM +0200, Jason A. Donenfeld wrote:
> > When the system reboots, the rng-seed that the FDT has should be
> > re-randomized, so that the new boot gets a new seed. Since the FDT is in
> > the ROM region at this point, we add a hook right after the ROM has been
> > added, so that we have a pointer to that copy of the FDT. When the
> > reboot happens, we then look for RNG seeds and replace their contents
> > with new random data.
> > 
> > Cc: Peter Maydell <peter.maydell@linaro.org>
> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> 
> Just FYI, I'm waiting for your feedback on this approach, first, before
> I add a similar thing for other architectures (at which point perhaps
> rerandomize_fdt_seeds will be moved into device_tree.c or something).

Actually, I think I'll generalize it now, and then we can evaluate it
all together. It actually looks a bit nicer split into patches. So I'll
have a replacement series for you shortly.

Jason