From: Matthias Brugger mbrugger@suse.com
When calling srand_mac we use a weak seed dependent on the mac address. If present, use a RNG device instead to incerase entropy.
Signed-off-by: Matthias Brugger mbrugger@suse.com
---
Changes in v3: - use IS_ENABLED instead of #if
Changes in v2: - fix dm_rng_read() parameters - add missing include file
net/net_rand.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/net/net_rand.h b/net/net_rand.h index 4bf9bd817e..6a52cda85e 100644 --- a/net/net_rand.h +++ b/net/net_rand.h @@ -10,6 +10,8 @@ #define __NET_RAND_H__
#include <common.h> +#include <dm/uclass.h> +#include <rng.h>
/* * Return a seed for the PRNG derived from the eth0 MAC address. @@ -37,7 +39,22 @@ static inline unsigned int seed_mac(void) */ static inline void srand_mac(void) { - srand(seed_mac()); + int 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(seed_mac()); }
#endif /* __NET_RAND_H__ */