From b674db54ca9a538703e1e3f129faee1f5fba70ef Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Wed, 7 May 2014 08:58:47 -0700
Subject: [PATCH] [v9_10] check for arc4random_addrandom()

3840.	[port]		Check for arc4random_addrandom() before using it;
			it's been removed from OpenBSD 5.5. [RT #35907]

(cherry picked from commit 1ea6e09c376b1351c614474a88675b1a9bda6571)
---
 CHANGES          |  3 +++
 acconfig.h       |  3 +++
 config.h.in      |  3 +++
 configure        |  9 ++++++++-
 configure.in     |  4 +++-
 lib/isc/random.c | 10 +++++++++-
 6 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index cd04d58202..7a40a28152 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3840.	[port]		Check for arc4random_addrandom() before using it;
+			it's been removed from OpenBSD 5.5. [RT #35907]
+
 3839.	[test]		Use only posix-compatible shell in system tests.
 			[RT #35625]
 
diff --git a/acconfig.h b/acconfig.h
index 34feb556a0..125d18e466 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -73,6 +73,9 @@
 /** define if arc4random() exists */
 #undef HAVE_ARC4RANDOM
 
+/** define if arc4random_addrandom() exists */
+#undef HAVE_ARC4RANDOM_ADDRANDOM
+
 /**
  * define if pthread_setconcurrency() should be called to tell the
  * OS how many threads we might want to run.
diff --git a/config.h.in b/config.h.in
index 0f6658fdf3..09d77b4265 100644
--- a/config.h.in
+++ b/config.h.in
@@ -73,6 +73,9 @@
 /** define if arc4random() exists */
 #undef HAVE_ARC4RANDOM
 
+/** define if arc4random_addrandom() exists */
+#undef HAVE_ARC4RANDOM_ADDRANDOM
+
 /**
  * define if pthread_setconcurrency() should be called to tell the
  * OS how many threads we might want to run.
diff --git a/configure b/configure
index ee3c490a03..21a014c2b3 100755
--- a/configure
+++ b/configure
@@ -14113,7 +14113,8 @@ fi
 
 
 #
-# Do we have arc4random() ?
+# Do we have arc4random(), etc ? arc4random_addrandom() has been removed
+# from OpenBSD 5.5 onwards.
 #
 ac_fn_c_check_func "$LINENO" "arc4random" "ac_cv_func_arc4random"
 if test "x$ac_cv_func_arc4random" = xyes; then :
@@ -14121,6 +14122,12 @@ if test "x$ac_cv_func_arc4random" = xyes; then :
 
 fi
 
+ac_fn_c_check_func "$LINENO" "arc4random_addrandom" "ac_cv_func_arc4random_addrandom"
+if test "x$ac_cv_func_arc4random_addrandom" = xyes; then :
+  $as_echo "#define HAVE_ARC4RANDOM_ADDRANDOM 1" >>confdefs.h
+
+fi
+
 
 #
 # Begin pthreads checking.
diff --git a/configure.in b/configure.in
index 43de6e6ebc..6bca7fe1ce 100644
--- a/configure.in
+++ b/configure.in
@@ -967,9 +967,11 @@ fi
 AC_SUBST(CHECK_DSA)
 
 #
-# Do we have arc4random() ?
+# Do we have arc4random(), etc ? arc4random_addrandom() has been removed
+# from OpenBSD 5.5 onwards.
 #
 AC_CHECK_FUNC(arc4random, AC_DEFINE(HAVE_ARC4RANDOM))
+AC_CHECK_FUNC(arc4random_addrandom, AC_DEFINE(HAVE_ARC4RANDOM_ADDRANDOM))
 
 sinclude(config.threads.in)dnl
 
diff --git a/lib/isc/random.c b/lib/isc/random.c
index 4c48e60fd7..624ac1bad9 100644
--- a/lib/isc/random.c
+++ b/lib/isc/random.c
@@ -67,8 +67,16 @@ isc_random_seed(isc_uint32_t seed)
 
 #ifndef HAVE_ARC4RANDOM
 	srand(seed);
-#else
+#elif defined(HAVE_ARC4RANDOM_ADDRANDOM)
 	arc4random_addrandom((u_char *) &seed, sizeof(isc_uint32_t));
+#else
+	/*
+	 * If arcrandom() 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.
+	 */
 #endif
 }