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) { + 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++)