| Message ID | 20201218092804.19753-2-matthias.bgg@kernel.org |
|---|---|
| State | Accepted |
| Commit | 92fdad28cfdf078fe34c198ef430933e7b2825a1 |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | Use RNG to get random behaviour | expand |
On Fri, 18 Dec 2020 10:28:03 +0100 matthias.bgg@kernel.org wrote: > From: Matthias Brugger <mbrugger@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 <mbrugger@suse.com> Reviewed-by: Torsten Duwe <duwe@suse.de>
On Fri, Dec 18, 2020 at 10:28:03AM +0100, matthias.bgg@kernel.org wrote: > From: Matthias Brugger <mbrugger@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 <mbrugger@suse.com> > Reviewed-by: Torsten Duwe <duwe@suse.de> Applied to u-boot/master, thanks!
Hi On 12/18/20 10:28 AM, matthias.bgg@kernel.org wrote: > From: Matthias Brugger <mbrugger@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 <mbrugger@suse.com> > > --- > > Changes in v3: > - use IS_ENABLED instead of #if > - use 4 byte for entropy > > 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..23af2b4800 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; > + u32 randv = 0; > + > + if (IS_ENABLED(CONFIG_DM_RNG)) { > + ret = uclass_get_device(UCLASS_RNG, 0, &devp); > + if (ret) { For information, as this patch already merged here we need to test if ret == 0: + if (!ret) { I push a patch to correct this test: "lib: uuid: fix the test on RNG device presence" http://patchwork.ozlabs.org/project/uboot/patch/20211022170544.1.Ib218a8a747f99cab44c3fac6af649f17f003b2e2@changeid/ > + ret = dm_rng_read(devp, &randv, sizeof(randv)); > + if (ret < 0) > + randv = 0; > + } > + } > + if (randv) > + srand(randv); > + else > + srand(get_ticks() + rand()); > > /* Set all fields randomly */ > for (i = 0; i < 4; i++) Regards Patrick
diff --git a/lib/uuid.c b/lib/uuid.c index e62d5ca264..23af2b4800 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; + u32 randv = 0; + + if (IS_ENABLED(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; + } + } + if (randv) + srand(randv); + else + srand(get_ticks() + rand()); /* Set all fields randomly */ for (i = 0; i < 4; i++)