From mboxrd@z Thu Jan 1 00:00:00 1970 From: matthias.bgg at kernel.org Date: Fri, 18 Dec 2020 10:28:04 +0100 Subject: [PATCH v3 2/2] net: Use NDRNG device in srand_mac() In-Reply-To: <20201218092804.19753-1-matthias.bgg@kernel.org> References: <20201218092804.19753-1-matthias.bgg@kernel.org> Message-ID: <20201218092804.19753-3-matthias.bgg@kernel.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 --- 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 +#include +#include /* * 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__ */ -- 2.29.2