summaryrefslogtreecommitdiff
path: root/src/shared/random-util.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/shared/random-util.c')
-rw-r--r--src/shared/random-util.c129
1 files changed, 0 insertions, 129 deletions
diff --git a/src/shared/random-util.c b/src/shared/random-util.c
deleted file mode 100644
index b230044f50..0000000000
--- a/src/shared/random-util.c
+++ /dev/null
@@ -1,129 +0,0 @@
-/***
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <stdint.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <time.h>
-#ifdef HAVE_SYS_AUXV_H
-#include <sys/auxv.h>
-#endif
-#include <linux/random.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;
-
- _cleanup_close_ int fd = -1;
- int r;
-
- /* Gathers some randomness from the kernel. This call will
- * 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
- * of seeding the hash functions for hashtable */
-
- /* Use the getrandom() syscall unless we know we don't have
- * it, or when the requested size is too large for it. */
- if (have_syscall != 0 || (size_t) (int) n != n) {
- r = getrandom(p, n, GRND_NONBLOCK);
- if (r == (int) n) {
- have_syscall = true;
- return 0;
- }
-
- if (r < 0) {
- if (errno == ENOSYS)
- /* we lack the syscall, continue with
- * reading from /dev/urandom */
- have_syscall = false;
- else if (errno == EAGAIN)
- /* not enough entropy for now. Let's
- * remember to use the syscall the
- * next time, again, but also read
- * from /dev/urandom for now, which
- * doesn't care about the current
- * amount of entropy. */
- have_syscall = true;
- else
- return -errno;
- } else
- /* too short read? */
- return -ENODATA;
- }
-
- fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
- if (fd < 0)
- return errno == ENOENT ? -ENOSYS : -errno;
-
- return loop_read_exact(fd, p, n, true);
-}
-
-void initialize_srand(void) {
- static bool srand_called = false;
- unsigned x;
-#ifdef HAVE_SYS_AUXV_H
- void *auxv;
-#endif
-
- 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... */
-
- auxv = (void*) getauxval(AT_RANDOM);
- if (auxv)
- x ^= *(unsigned*) auxv;
-#endif
-
- x ^= (unsigned) now(CLOCK_REALTIME);
- x ^= (unsigned) gettid();
-
- srand(x);
- srand_called = true;
-}
-
-void random_bytes(void *p, size_t n) {
- uint8_t *q;
- int r;
-
- r = dev_urandom(p, n);
- if (r >= 0)
- return;
-
- /* If some idiot made /dev/urandom unavailable to us, he'll
- * get a PRNG instead. */
-
- initialize_srand();
-
- for (q = p; q < (uint8_t*) p + n; q ++)
- *q = rand();
-}