From 282b61a64921775e5d167df942347a8a3cf984e7 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 30 Apr 2022 15:25:55 +0200 Subject: [PATCH] seedrng: prepare read_new_seed() to not need a "success" retval We do not expect /dev/[u]random to be not openable/readable. If they are, just bail out (something is obviously very wrong). function old new delta seedrng_main 1077 1076 -1 .rodata 104939 104929 -10 Signed-off-by: Denys Vlasenko --- util-linux/seedrng.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/util-linux/seedrng.c b/util-linux/seedrng.c index 82c69b72b..3f4c5c0c8 100644 --- a/util-linux/seedrng.c +++ b/util-linux/seedrng.c @@ -79,25 +79,27 @@ static int read_new_seed(uint8_t *seed, size_t len, bool *is_creditable) { ssize_t ret; - *is_creditable = false; ret = getrandom(seed, len, GRND_NONBLOCK); if (ret == (ssize_t)len) { *is_creditable = true; return 0; - } else if (ret < 0 && errno == ENOSYS) { + } + if (ret < 0 && errno == ENOSYS) { struct pollfd random_fd = { - .fd = open("/dev/random", O_RDONLY), + .fd = xopen("/dev/random", O_RDONLY), .events = POLLIN }; - if (random_fd.fd < 0) - return -1; *is_creditable = poll(&random_fd, 1, 0) == 1; close(random_fd.fd); - } else if (getrandom(seed, len, GRND_INSECURE) == (ssize_t)len) - return 0; - if (open_read_close("/dev/urandom", seed, len) == (ssize_t)len) - return 0; - return -1; + } else { + *is_creditable = false; + if (getrandom(seed, len, GRND_INSECURE) == (ssize_t)len) + return 0; + } + errno = 0; + if (open_read_close("/dev/urandom", seed, len) != (ssize_t)len) + bb_perror_msg_and_die("can't read '%s'", "/dev/urandom"); + return 0; } static void seed_rng(uint8_t *seed, size_t len, bool credit)