From mboxrd@z Thu Jan 1 00:00:00 1970 From: matthias.bgg at kernel.org Date: Fri, 18 Dec 2020 10:28:03 +0100 Subject: [PATCH v3 1/2] lib: uuid: use RNG device if present In-Reply-To: <20201218092804.19753-1-matthias.bgg@kernel.org> References: <20201218092804.19753-1-matthias.bgg@kernel.org> Message-ID: <20201218092804.19753-2-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 calculating a random UUID we use a weak seed. Use a RNG device if present to increase entropy. Signed-off-by: Matthias Brugger --- Changes in v3: - use IS_ENABLED instead of #if - use 4 byte for entropy Changes in v2: - fix dm_rng_read() parameters - add missing include lib/uuid.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/lib/uuid.c b/lib/uuid.c index e62d5ca264..23af2b4800 100644 --- a/lib/uuid.c +++ b/lib/uuid.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include /* * UUID - Universally Unique IDentifier - 128 bits unique number. @@ -249,9 +251,22 @@ void gen_rand_uuid(unsigned char *uuid_bin) { u32 ptr[4]; struct uuid *uuid = (struct uuid *)ptr; - int i; - - srand(get_ticks() + rand()); + int i, 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(get_ticks() + rand()); /* Set all fields randomly */ for (i = 0; i < 4; i++) -- 2.29.2