Hi Mattias,
On Wed, 16 Dec 2020 at 09:28, <matthias....@kernel.org> wrote:
>
> From: Matthias Brugger <mbrug...@suse.com>
>
> When calculating a random UUID we use a weak seed.
> Use a RNG device if present to increase entropy.
>
> Signed-off-by: Matthias Brugger <mbrug...@suse.com>
>
> ---
>
> Changes in v2:
> - fix dm_rng_read() parameters
> - add missing include
>
> lib/uuid.c | 21 ++++++++++++++++++---
> 1 file changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/lib/uuid.c b/lib/uuid.c
> index e62d5ca264..e3487380c3 100644
> --- a/lib/uuid.c
> +++ b/lib/uuid.c
> @@ -15,6 +15,8 @@
> #include <asm/io.h>
> #include <part_efi.h>
> #include <malloc.h>
> +#include <dm/uclass.h>
> +#include <rng.h>
>
> /*
> * UUID - Universally Unique IDentifier - 128 bits unique number.
> @@ -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;
> +
> +#if defined(CONFIG_DM_RNG)
This seems a little backwards to me. The caller should request a RNG
device, getting either a hardware one or a software one, and then call
the uclass method to get the uuid.
> + ret = uclass_get_device(UCLASS_RNG, 0, &devp);
> + if (ret) {
> + ret = dm_rng_read(devp, &randv, sizeof(randv));
> + if (ret < 0)
> + randv = 0;
> + }
> + if (randv)
> + srand(randv);
> + else
> +#endif
> + srand(get_ticks() + rand());
>
> /* Set all fields randomly */
> for (i = 0; i < 4; i++)
> --
> 2.29.2
>
Regards,
Simon
