Re: [PATCH v2 1/2] lib: uuid: use RNG device if present

18 Dec 2020


      On Fri, Dec 18, 2020 at 09:37:28AM +0100, Torsten Duwe wrote:
...
On Wed, 16 Dec 2020 17:28:06 +0100
matthias.bgg@kernel.org wrote:
...
@@ -249,9 +251,22 @@ void gen_rand_uuid(unsigned char *uuid_bin)
 {
   u32 ptr[4];
   struct uuid *uuid = (struct uuid *)ptr;

int i;

srand(get_ticks() + rand());


int i, ret;
struct udevice *devp;
u8 randv = 0;

^^
Only 1 byte? The UUID could use some more, and, having a HW RNG, it
doesn't hurt to seed it with more entropy here. I suggest using u32 as
well.
...



+#if defined(CONFIG_DM_RNG)

ret = uclass_get_device(UCLASS_RNG, 0, &devp);
if (ret) {
ret = dm_rng_read(devp, &randv, sizeof(randv));


if (ret < 0)


	randv = 0;


}

See my reply to the cover letter. I'd suggest to wrap this with
   if (IS_ENABLED(CONFIG_DM_RNG))
instead, likewise for the MAC.
Sounds good, I'll send a new version addressing both issues.
Thanks for the review.
Matthias

    

mbrugger