mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-16 23:18:51 +09:00
![Matthias Brugger](/assets/img/avatar_default.png)
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> Reviewed-by: Torsten Duwe <duwe@suse.de>
61 lines
1.1 KiB
C
61 lines
1.1 KiB
C
/*
|
|
* Copied from LiMon - BOOTP.
|
|
*
|
|
* Copyright 1994, 1995, 2000 Neil Russell.
|
|
* (See License)
|
|
* Copyright 2000 Paolo Scaffardi
|
|
*/
|
|
|
|
#ifndef __NET_RAND_H__
|
|
#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.
|
|
*/
|
|
static inline unsigned int seed_mac(void)
|
|
{
|
|
unsigned char enetaddr[ARP_HLEN];
|
|
unsigned int seed;
|
|
|
|
/* get our mac */
|
|
memcpy(enetaddr, eth_get_ethaddr(), ARP_HLEN);
|
|
|
|
seed = enetaddr[5];
|
|
seed ^= enetaddr[4] << 8;
|
|
seed ^= enetaddr[3] << 16;
|
|
seed ^= enetaddr[2] << 24;
|
|
seed ^= enetaddr[1];
|
|
seed ^= enetaddr[0] << 8;
|
|
|
|
return seed;
|
|
}
|
|
|
|
/*
|
|
* Seed the random number generator using the eth0 MAC address.
|
|
*/
|
|
static inline void srand_mac(void)
|
|
{
|
|
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__ */
|