From mboxrd@z Thu Jan 1 00:00:00 1970 From: Torsten Duwe Date: Wed, 16 Dec 2020 14:20:37 +0100 Subject: [PATCH 2/2] net: Use NDRNG device in srand_mac() In-Reply-To: <20201216104117.10836-3-matthias.bgg@kernel.org> References: <20201216104117.10836-1-matthias.bgg@kernel.org> <20201216104117.10836-3-matthias.bgg@kernel.org> Message-ID: <20201216142014.43a583c4@blackhole.lan> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, 16 Dec 2020 11:41:17 +0100 matthias.bgg at kernel.org wrote: > From: Matthias Brugger > > 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 > > --- > > net/net_rand.h | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/net/net_rand.h b/net/net_rand.h > index 4bf9bd817e..600c3d825e 100644 > --- a/net/net_rand.h > +++ b/net/net_rand.h > @@ -10,6 +10,7 @@ > #define __NET_RAND_H__ > > #include > +#include > > /* > * Return a seed for the PRNG derived from the eth0 MAC address. > @@ -37,7 +38,22 @@ static inline unsigned int seed_mac(void) > */ > static inline void srand_mac(void) > { > - srand(seed_mac()); > +#if defined(CONFIG_DM_RNG) > + int ret; > + struct udevice *devp; > + u32 randv = 0; > + > + ret = uclass_get_device(UCLASS_RNG, 0, &devp); > + if (ret) { > + ret = dm_rng_read(dev, randv, sizeof(randv)); Haven't tested this (yet), but shouldn't this be ret = dm_rng_read(devp, &randv, sizeof(randv)); ^ ^ ? > + if (ret < 0) > + randv = 0; > + } > + if (randv) > + srand(randv); > + else > +#endif > + srand(seed_mac()); > } > > #endif /* __NET_RAND_H__ */