From ca93ca23409b827b48a2fc0a692496d3f7b67944 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Tue, 29 Mar 2022 21:31:25 -0400 Subject: [PATCH] wireguard: selftests: simplify RNG seeding The seed_rng() function was written to work across lots of old kernels, back when WireGuard used a big compatibility layer. Now that things have evolved, we can vastly simplify this, by just marking the RNG as seeded. Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski --- tools/testing/selftests/wireguard/qemu/init.c | 26 +++++-------------- 1 file changed, 7 insertions(+), 19 deletions(-) diff --git a/tools/testing/selftests/wireguard/qemu/init.c b/tools/testing/selftests/wireguard/qemu/init.c index c9698120ac9d..0b45055d9de0 100644 --- a/tools/testing/selftests/wireguard/qemu/init.c +++ b/tools/testing/selftests/wireguard/qemu/init.c @@ -56,26 +56,14 @@ static void print_banner(void) static void seed_rng(void) { - int fd; - struct { - int entropy_count; - int buffer_size; - unsigned char buffer[256]; - } entropy = { - .entropy_count = sizeof(entropy.buffer) * 8, - .buffer_size = sizeof(entropy.buffer), - .buffer = "Adding real entropy is not actually important for these tests. Don't try this at home, kids!" - }; + int bits = 256, fd; - if (mknod("/dev/urandom", S_IFCHR | 0644, makedev(1, 9))) - panic("mknod(/dev/urandom)"); - fd = open("/dev/urandom", O_WRONLY); + pretty_message("[+] Fake seeding RNG..."); + fd = open("/dev/random", O_WRONLY); if (fd < 0) - panic("open(urandom)"); - for (int i = 0; i < 256; ++i) { - if (ioctl(fd, RNDADDENTROPY, &entropy) < 0) - panic("ioctl(urandom)"); - } + panic("open(random)"); + if (ioctl(fd, RNDADDTOENTCNT, &bits) < 0) + panic("ioctl(RNDADDTOENTCNT)"); close(fd); } @@ -270,10 +258,10 @@ static void check_leaks(void) int main(int argc, char *argv[]) { - seed_rng(); ensure_console(); print_banner(); mount_filesystems(); + seed_rng(); kmod_selftests(); enable_logging(); clear_leaks();