From 5b76a09697bfc76f5acefd65d5b37b1214d271a8 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Wed, 4 Dec 2002 01:19:28 +0000
Subject: [PATCH] 1405.   [func]          Use arc4random() if available. from:
 jakob@crt.se reviewed: marka

---
 CHANGES               |  2 ++
 acconfig.h            |  5 ++++-
 bin/tests/genrandom.c |  8 +++++++-
 configure.in          |  7 ++++++-
 lib/dns/rdataset.c    | 10 +++++++++-
 lib/isc/random.c      | 16 +++++++++++++++-
 6 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/CHANGES b/CHANGES
index e834472982..2ae45c1df1 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+1405.	[func]		Use arc4random() if available.
+
 1404.	[bug]		libbind: ns_name_ntol() could overwite a zero length
 			buffer.
 
diff --git a/acconfig.h b/acconfig.h
index b04dc0db4d..814b9fdd69 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: acconfig.h,v 1.38 2002/10/15 04:32:49 marka Exp $ */
+/* $Id: acconfig.h,v 1.39 2002/12/04 01:19:27 marka Exp $ */
 
 /***
  *** This file is not to be included by any public header files, because
@@ -76,6 +76,9 @@
 /* define if gai_strerror() exists */
 #undef HAVE_GAISTRERROR
 
+/* define if arc4random() exists */
+#undef HAVE_ARC4RANDOM
+
 /* define if pthread_setconcurrency() should be called to tell the
  * OS how many threads we might want to run.
  */
diff --git a/bin/tests/genrandom.c b/bin/tests/genrandom.c
index e90cbacc65..800623ccaf 100644
--- a/bin/tests/genrandom.c
+++ b/bin/tests/genrandom.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: genrandom.c,v 1.8 2001/01/09 21:41:04 bwelling Exp $ */
+/* $Id: genrandom.c,v 1.9 2002/12/04 01:19:28 marka Exp $ */
 
 #include <config.h>
 
@@ -47,9 +47,15 @@ main(int argc, char **argv) {
 		exit(1);
 	}
 
+#ifndef HAVE_ARC4RANDOM
 	srand(0x12345678);
+#endif
 	while (bytes > 0) {
+#ifndef HAVE_ARC4RANDOM
 		unsigned short int x = (rand() & 0xFFFF);
+#else
+		unsigned short int x = (arc4random() & 0xFFFF);
+#endif
 		unsigned char c = x & 0xFF;
 		if (putc(c, fp) == EOF) {
 			printf("error writing to file\n");
diff --git a/configure.in b/configure.in
index 917953a495..8b99fb23be 100644
--- a/configure.in
+++ b/configure.in
@@ -18,7 +18,7 @@ AC_DIVERT_PUSH(AC_DIVERSION_NOTICE)dnl
 esyscmd([sed "s/^/# /" COPYRIGHT])dnl
 AC_DIVERT_POP()dnl
 
-AC_REVISION($Revision: 1.333 $)
+AC_REVISION($Revision: 1.334 $)
 
 AC_INIT(lib/dns/name.c)
 AC_PREREQ(2.13)
@@ -521,6 +521,11 @@ case "$use_randomdev" in
 		;;
 esac
 
+#
+# Do we have arc4random() ?
+#
+AC_CHECK_FUNC(arc4random, AC_DEFINE(HAVE_ARC4RANDOM))
+
 #
 # Begin pthreads checking.
 #
diff --git a/lib/dns/rdataset.c b/lib/dns/rdataset.c
index aca841ca21..2b3c0c22c4 100644
--- a/lib/dns/rdataset.c
+++ b/lib/dns/rdataset.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: rdataset.c,v 1.63 2002/04/02 06:06:29 marka Exp $ */
+/* $Id: rdataset.c,v 1.64 2002/12/04 01:19:28 marka Exp $ */
 
 #include <config.h>
 
@@ -370,7 +370,11 @@ towiresorted(dns_rdataset_t *rdataset, dns_name_t *owner_name,
 			 */
 			for (i = 0; i < count; i++) {
 				dns_rdata_t rdata;
+#ifndef HAVE_ARC4RANDOM
 				choice = i + (((u_int)rand()>>3) % (count - i));
+#else
+				choice = i + (((u_int)arc4random()>>3) % (count - i));
+#endif
 				rdata = shuffled[i];
 				shuffled[i] = shuffled[choice];
 				shuffled[choice] = rdata;
@@ -385,7 +389,11 @@ towiresorted(dns_rdataset_t *rdataset, dns_name_t *owner_name,
 			/*
 			 * "Cyclic" order.
 			 */
+#ifndef HAVE_ARC4RANDOM
 			unsigned int j = (((unsigned int)rand()) >> 3) % count;
+#else
+			unsigned int j = (((unsigned int)arc4random()) >> 3) % count;
+#endif
 			for (i = 0; i < count; i++) {
 				if (order != NULL)
 					sorted[j].key = (*order)(&shuffled[i],
diff --git a/lib/isc/random.c b/lib/isc/random.c
index 4ed13d977d..c52b9a9957 100644
--- a/lib/isc/random.c
+++ b/lib/isc/random.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: random.c,v 1.15 2001/01/09 21:56:22 bwelling Exp $ */
+/* $Id: random.c,v 1.16 2002/12/04 01:19:28 marka Exp $ */
 
 #include <config.h>
 
@@ -33,7 +33,9 @@ static isc_once_t once = ISC_ONCE_INIT;
 static void
 initialize_rand(void)
 {
+#ifndef HAVE_ARC4RANDOM
 	srand(time(NULL));
+#endif
 }
 
 static void
@@ -47,7 +49,11 @@ isc_random_seed(isc_uint32_t seed)
 {
 	initialize();
 
+#ifndef HAVE_ARC4RANDOM
 	srand(seed);
+#else
+	arc4random_addrandom((u_char *) &seed, sizeof(isc_uint32_t));
+#endif
 }
 
 void
@@ -57,7 +63,11 @@ isc_random_get(isc_uint32_t *val)
 
 	initialize();
 
+#ifndef HAVE_ARC4RANDOM
 	*val = rand();
+#else
+	*val = arc4random();
+#endif
 }
 
 isc_uint32_t
@@ -66,5 +76,9 @@ isc_random_jitter(isc_uint32_t max, isc_uint32_t jitter) {
 	if (jitter == 0)
 		return (max);
 	else
+#ifndef HAVE_ARC4RANDOM
 		return (max - rand() % jitter);
+#else
+		return (max - arc4random() % jitter);
+#endif
 }