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authorOtto Moerbeek <otto@cvs.openbsd.org>2005-11-30 07:51:03 +0000
committerOtto Moerbeek <otto@cvs.openbsd.org>2005-11-30 07:51:03 +0000
commit1fcb44d8d6accf4b13417c63d21bd922f79d386a (patch)
treed5f0eb26e09410e4bf7f6d954c2e138b95ccd125 /lib/libc/stdlib
parent0f97be5213bc1c35042f4403759d8c954c4e631a (diff)
Use sysctl(KERN_ARND) to get n bytes, instead of just 4 at a time
and remove fallback code. If somebody is dumb enough to make the sysctl fail using systrace, he deserves what he gets. Saves 7 syscalls on process startup. looks good miod@ ok deraadt@ tedu@
Diffstat (limited to 'lib/libc/stdlib')
-rw-r--r--lib/libc/stdlib/random.37
-rw-r--r--lib/libc/stdlib/random.c49
2 files changed, 14 insertions, 42 deletions
diff --git a/lib/libc/stdlib/random.3 b/lib/libc/stdlib/random.3
index f43f06420dc..626b040b505 100644
--- a/lib/libc/stdlib/random.3
+++ b/lib/libc/stdlib/random.3
@@ -25,7 +25,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.\" $OpenBSD: random.3,v 1.17 2003/06/02 20:18:38 millert Exp $
+.\" $OpenBSD: random.3,v 1.18 2005/11/30 07:51:02 otto Exp $
.\"
.Dd April 19, 1991
.Dt RANDOM 3
@@ -89,9 +89,8 @@ as the seed.
.Pp
The
.Fn srandomdev
-routine initializes a state array using the
-.Xr arandom 4
-random number device which returns good random numbers,
+routine initializes a state array using
+random numbers obtained from the kernel,
suitable for cryptographic use.
Note that this particular seeding procedure can generate
states which are impossible to reproduce by calling
diff --git a/lib/libc/stdlib/random.c b/lib/libc/stdlib/random.c
index 565542ecdb2..48e892042ba 100644
--- a/lib/libc/stdlib/random.c
+++ b/lib/libc/stdlib/random.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: random.c,v 1.14 2005/08/08 08:05:37 espie Exp $ */
+/* $OpenBSD: random.c,v 1.15 2005/11/30 07:51:02 otto Exp $ */
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
@@ -220,17 +220,17 @@ srandom(unsigned int x)
* srandomdev:
*
* Many programs choose the seed value in a totally predictable manner.
- * This often causes problems. We seed the generator using the much more
- * secure arandom(4) interface. Note that this particular seeding
- * procedure can generate states which are impossible to reproduce by
- * calling srandom() with any value, since the succeeding terms in the
- * state buffer are no longer derived from the LC algorithm applied to
- * a fixed seed.
+ * This often causes problems. We seed the generator using random
+ * data from the kernel.
+ * Note that this particular seeding procedure can generate states
+ * which are impossible to reproduce by calling srandom() with any
+ * value, since the succeeding terms in the state buffer are no longer
+ * derived from the LC algorithm applied to a fixed seed.
*/
void
srandomdev(void)
{
- int fd, i, mib[2], n;
+ int mib[2];
size_t len;
if (rand_type == TYPE_0)
@@ -238,36 +238,9 @@ srandomdev(void)
else
len = rand_deg * sizeof(state[0]);
- /*
- * To get seed data, first try reading from /dev/arandom.
- * If that fails, try the KERN_ARND sysctl() (one int at a time).
- * As a last resort, call srandom().
- */
- if ((fd = open("/dev/arandom", O_RDONLY, 0)) != -1 &&
- read(fd, (void *) state, len) == (ssize_t) len) {
- close(fd);
- } else {
- if (fd != -1)
- close(fd);
- mib[0] = CTL_KERN;
- mib[1] = KERN_ARND;
- n = len / sizeof(int);
- len = sizeof(int);
- for (i = 0; i < n; i++) {
- if (sysctl(mib, 2, (char *)((int *)state + i), &len,
- NULL, 0) == -1)
- break;
- }
- if (i != n) {
- struct timeval tv;
- u_int junk;
-
- /* XXX - this could be better */
- gettimeofday(&tv, NULL);
- srandom(getpid() ^ tv.tv_sec ^ tv.tv_usec ^ junk);
- return;
- }
- }
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_ARND;
+ sysctl(mib, 2, state, &len, NULL, 0);
if (rand_type != TYPE_0) {
fptr = &state[rand_sep];