Update to bind-9.10.5-P3, which appears to have been the last ISC version.

We only use this tree to build dig and nslookup. Our previous version
predated edns0 support in those tools, and we want that.  This is the worst
code I've looked at in years, with layers and layers of spaghetti abstraction
clearly unfit for reuse, but then reused anyways, and the old ones remain
behind.  So this is a 8MB diff.
florian, sthen, and otto tried this merge before but failed.

1 files changed, 35 insertions, 52 deletions

diff --git a/usr.sbin/bind/lib/isc/random.c b/usr.sbin/bind/lib/isc/random.c
index 8730d5213e9..1199c5eb766 100644
--- a/usr.sbin/bind/lib/isc/random.c
+++ b/usr.sbin/bind/lib/isc/random.c
@@ -1,9 +1,8 @@
 /*
- * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2004, 2005, 2007, 2009, 2013, 2014, 2016  Internet Systems Consortium, Inc. ("ISC")
  * Copyright (C) 1999-2003  Internet Software Consortium.
- * Copyright (C) 2008 Damien Miller
  *
- * Permission to use, copy, modify, and distribute this software for any
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
@@ -16,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $ISC: random.c,v 1.21.18.2 2005/04/29 00:16:48 marka Exp $ */
+/* $Id: random.c,v 1.10 2019/12/16 16:16:26 deraadt Exp $ */
 
 /*! \file */
 
@@ -44,14 +43,14 @@ initialize_rand(void)
 {
 #ifndef HAVE_ARC4RANDOM
 	unsigned int pid = getpid();
-	
+
 	/*
 	 * The low bits of pid generally change faster.
 	 * Xor them with the high bits of time which change slowly.
 	 */
 	pid = ((pid << 16) & 0xffff0000) | ((pid >> 16) & 0xffff);
 
-	srand(time(NULL) ^ pid);
+	srand((unsigned)time(NULL) ^ pid);
 #endif
 }
 
@@ -68,6 +67,21 @@ isc_random_seed(isc_uint32_t seed)
 
 #ifndef HAVE_ARC4RANDOM
 	srand(seed);
+#elif defined(HAVE_ARC4RANDOM_STIR)
+	/* Formally not necessary... */
+	UNUSED(seed);
+	arc4random_stir();
+#elif defined(HAVE_ARC4RANDOM_ADDRANDOM)
+	arc4random_addrandom((u_char *) &seed, sizeof(isc_uint32_t));
+#else
+       /*
+	* If arc4random() is available and no corresponding seeding
+	* function arc4random_addrandom() is available, no seeding is
+	* done on such platforms (e.g., OpenBSD 5.5).  This is because
+	* the OS itself is supposed to seed the RNG and it is assumed
+	* that no explicit seeding is required.
+	*/
+       UNUSED(seed);
 #endif
 }
 
@@ -83,61 +97,30 @@ isc_random_get(isc_uint32_t *val)
 	 * rand()'s lower bits are not random.
 	 * rand()'s upper bit is zero.
 	 */
+#if RAND_MAX >= 0xfffff
+	/* We have at least 20 bits.  Use lower 16 excluding lower most 4 */
 	*val = ((rand() >> 4) & 0xffff) | ((rand() << 12) & 0xffff0000);
+#elif RAND_MAX >= 0x7fff
+	/* We have at least 15 bits.  Use lower 10/11 excluding lower most 4 */
+	*val = ((rand() >> 4) & 0x000007ff) | ((rand() << 7) & 0x003ff800) |
+		((rand() << 18) & 0xffc00000);
 #else
-	*val = arc4random();
+#error RAND_MAX is too small
 #endif
-}
-
-isc_uint32_t
-isc_random_uniform(isc_uint32_t upper_bound)
-{
-	isc_uint32_t r, min;
-
-	/*
-	 * Uniformity is achieved by generating new random numbers until
-	 * the one returned is outside the range [0, 2**32 % upper_bound).
-	 * This guarantees the selected random number will be inside
-	 * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
-	 * after reduction modulo upper_bound.
-	 */
-
-	if (upper_bound < 2)
-		return 0;
-
-#if (ULONG_MAX > 0xffffffffUL)
-	min = 0x100000000UL % upper_bound;
 #else
-	/* Calculate (2**32 % upper_bound) avoiding 64-bit math */
-	if (upper_bound > 0x80000000)
-		min = 1 + ~upper_bound;		/* 2**32 - upper_bound */
-	else {
-		/* (2**32 - x) % x == 2**32 % x when x <= 2**31 */
-		min = ((0xffffffff - upper_bound) + 1) % upper_bound;
-	}
+	*val = arc4random();
 #endif
-
-	/*
-	 * This could theoretically loop forever doing this, but each retry
-	 * has p > 0.5 (worst case, usually far better) of selecting a
-	 * number inside the range we need, so it should rarely need to
-	 * re-roll.
-	 */
-	for (;;) {
-		isc_random_get(&r);
-		if (r >= min)
-			break;
-	}
-
-	return r % upper_bound;
 }
 
 isc_uint32_t
 isc_random_jitter(isc_uint32_t max, isc_uint32_t jitter) {
-	REQUIRE(jitter < max);
+	isc_uint32_t rnd;
+
+	REQUIRE(jitter < max || (jitter == 0 && max == 0));
+
 	if (jitter == 0)
 		return (max);
-	else
-		return max - isc_random_uniform(jitter);
-}
 
+	isc_random_get(&rnd);
+	return (max - rnd % jitter);
+}