| /* |
| * Copyright 2017 Timothy Arceri |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| * |
| */ |
| |
| #include "detect_os.h" |
| |
| #if !DETECT_OS_WINDOWS |
| #if defined(HAVE_GETRANDOM) |
| #include <sys/random.h> |
| #endif |
| #include <unistd.h> |
| #include <fcntl.h> |
| #endif |
| |
| #include <time.h> |
| |
| #include "rand_xor.h" |
| |
| /* Super fast random number generator. |
| * |
| * This rand_xorshift128plus function by Sebastiano Vigna belongs |
| * to the public domain. |
| */ |
| uint64_t |
| rand_xorshift128plus(uint64_t seed[2]) |
| { |
| uint64_t *s = seed; |
| |
| uint64_t s1 = s[0]; |
| const uint64_t s0 = s[1]; |
| s[0] = s0; |
| s1 ^= s1 << 23; |
| s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); |
| |
| return s[1] + s0; |
| } |
| |
| void |
| s_rand_xorshift128plus(uint64_t seed[2], bool randomised_seed) |
| { |
| if (!randomised_seed) { |
| /* Use a fixed seed */ |
| seed[0] = 0x3bffb83978e24f88; |
| seed[1] = 0x9238d5d56c71cd35; |
| return; |
| } |
| |
| #if !DETECT_OS_WINDOWS |
| size_t seed_size = sizeof(uint64_t) * 2; |
| |
| #if defined(HAVE_GETRANDOM) |
| ssize_t ret = getrandom(seed, seed_size, GRND_NONBLOCK); |
| if (ret == seed_size) |
| return; |
| #endif |
| |
| int fd = open("/dev/urandom", O_RDONLY); |
| if (fd >= 0) { |
| if (read(fd, seed, seed_size) == seed_size) { |
| close(fd); |
| return; |
| } |
| close(fd); |
| } |
| #endif |
| |
| seed[0] = 0x3bffb83978e24f88; |
| seed[1] = time(NULL); |
| } |