lib: uuid: use RNG device if present

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>

diff --git a/lib/uuid.c b/lib/uuid.c
index 54a93aa..5bc6867 100644 (file)
--- 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++)