ea707dc0aa
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
/*
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* Copied from LiMon - BOOTP.
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*
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* Copyright 1994, 1995, 2000 Neil Russell.
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* (See License)
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* Copyright 2000 Paolo Scaffardi
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*/
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#ifndef __NET_RAND_H__
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#define __NET_RAND_H__
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#include <common.h>
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#include <dm/uclass.h>
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#include <rng.h>
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/*
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* Return a seed for the PRNG derived from the eth0 MAC address.
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*/
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static inline unsigned int seed_mac(void)
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{
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unsigned char enetaddr[ARP_HLEN];
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unsigned int seed;
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/* get our mac */
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memcpy(enetaddr, eth_get_ethaddr(), ARP_HLEN);
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seed = enetaddr[5];
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seed ^= enetaddr[4] << 8;
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seed ^= enetaddr[3] << 16;
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seed ^= enetaddr[2] << 24;
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seed ^= enetaddr[1];
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seed ^= enetaddr[0] << 8;
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return seed;
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}
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/*
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* Seed the random number generator using the eth0 MAC address.
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*/
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static inline void srand_mac(void)
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{
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int ret;
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struct udevice *devp;
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u32 randv = 0;
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if (IS_ENABLED(CONFIG_DM_RNG)) {
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ret = uclass_get_device(UCLASS_RNG, 0, &devp);
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if (ret) {
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ret = dm_rng_read(devp, &randv, sizeof(randv));
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if (ret < 0)
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randv = 0;
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}
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}
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if (randv)
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srand(randv);
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else
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srand(seed_mac());
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}
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#endif /* __NET_RAND_H__ */
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