Use arc4random_buf() when requesting more than a single word of output

Use arc4random_uniform() when the desired random number upper bound
is not a power of two
ok deraadt@ millert@

src/lib/libc/stdlib/malloc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.88 2008/02/20 18:31:34 otto Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.89 2008/04/13 00:22:16 djm Exp $	*/
 
 /*
  * ----------------------------------------------------------------------------
@@ -1140,7 +1140,7 @@ malloc_bytes(size_t size)
 
 	if (malloc_guard) {
 		/* Walk to a random position. */
-		i = arc4random() % bp->free;
+		i = arc4random_uniform(bp->free);
 		while (i > 0) {
 			u += u;
 			k++;

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.103 2008/01/28 11:45:59 mpf Exp $ */
+/*	$OpenBSD: ntp.c,v 1.104 2008/04/13 00:22:17 djm Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -659,7 +659,7 @@ scale_interval(time_t requested)
 	time_t interval, r;
 
 	interval = requested * conf->scale;
-	r = arc4random() % MAX(5, interval / 10);
+	r = arc4random_uniform(MAX(5, interval / 10));
 	return (interval + r);
 }
 
@@ -669,7 +669,7 @@ error_interval(void)
 	time_t interval, r;
 
 	interval = INTERVAL_QUERY_PATHETIC * QSCALE_OFF_MAX / QSCALE_OFF_MIN;
-	r = arc4random() % (interval / 10);
+	r = arc4random_uniform(interval / 10);
 	return (interval + r);
 }