diff options
Diffstat (limited to 'src/basic/random-util.c')
| -rw-r--r-- | src/basic/random-util.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/src/basic/random-util.c b/src/basic/random-util.c index b230044f50..ad7b3eedf2 100644 --- a/src/basic/random-util.c +++ b/src/basic/random-util.c @@ -17,21 +17,24 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include <stdint.h> +#include <elf.h> #include <errno.h> -#include <sys/types.h> -#include <sys/stat.h> #include <fcntl.h> -#include <time.h> +#include <stdbool.h> +#include <stdlib.h> +#include <sys/time.h> +#include <linux/random.h> +#include <stdint.h> + #ifdef HAVE_SYS_AUXV_H #include <sys/auxv.h> #endif -#include <linux/random.h> +#include "fd-util.h" +#include "io-util.h" +#include "missing.h" #include "random-util.h" #include "time-util.h" -#include "missing.h" -#include "util.h" int dev_urandom(void *p, size_t n) { static int have_syscall = -1; @@ -43,7 +46,7 @@ int dev_urandom(void *p, size_t n) { * never block, and will always return some data from the * kernel, regardless if the random pool is fully initialized * or not. It thus makes no guarantee for the quality of the - * returned entropy, but is good enough for or usual usecases + * returned entropy, but is good enough for our usual usecases * of seeding the hash functions for hashtable */ /* Use the getrandom() syscall unless we know we don't have @@ -92,17 +95,18 @@ void initialize_srand(void) { if (srand_called) return; - x = 0; - #ifdef HAVE_SYS_AUXV_H - /* The kernel provides us with a bit of entropy in auxv, so - * let's try to make use of that to seed the pseudo-random - * generator. It's better than nothing... */ + /* The kernel provides us with 16 bytes of entropy in auxv, so let's try to make use of that to seed the + * pseudo-random generator. It's better than nothing... */ auxv = (void*) getauxval(AT_RANDOM); - if (auxv) - x ^= *(unsigned*) auxv; + if (auxv) { + assert_cc(sizeof(x) < 16); + memcpy(&x, auxv, sizeof(x)); + } else #endif + x = 0; + x ^= (unsigned) now(CLOCK_REALTIME); x ^= (unsigned) gettid(); |