From 6541168d7037457b8e5c51cc354f11bd94e618b6 Mon Sep 17 00:00:00 2001
From: Marek Sebera <marek.sebera@gmail.com>
Date: Mon, 6 Mar 2017 00:55:16 +0300
Subject: [PATCH] Detect arch4random_addrandom() existence

Refs: #370
Refs: #475
---
 CMakeLists.txt        | 1 +
 configure.ac          | 1 +
 evutil_rand.c         | 2 ++
 include/event2/util.h | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a861e7d96..f609d02d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -338,6 +338,7 @@ CHECK_FUNCTION_EXISTS_EX(sysctl EVENT__HAVE_SYSCTL)
 CHECK_FUNCTION_EXISTS_EX(accept4 EVENT__HAVE_ACCEPT4)
 CHECK_FUNCTION_EXISTS_EX(arc4random EVENT__HAVE_ARC4RANDOM)
 CHECK_FUNCTION_EXISTS_EX(arc4random_buf EVENT__HAVE_ARC4RANDOM_BUF)
+CHECK_FUNCTION_EXISTS_EX(arc4random_addrandom EVENT__HAVE_ARC4RANDOM_ADDRANDOM)
 CHECK_FUNCTION_EXISTS_EX(epoll_create1 EVENT__HAVE_EPOLL_CREATE1)
 CHECK_FUNCTION_EXISTS_EX(getegid EVENT__HAVE_GETEGID)
 CHECK_FUNCTION_EXISTS_EX(geteuid EVENT__HAVE_GETEUID)
diff --git a/configure.ac b/configure.ac
index a127bbc91..e73c29b14 100644
--- a/configure.ac
+++ b/configure.ac
@@ -342,6 +342,7 @@ AC_CHECK_FUNCS([ \
   accept4 \
   arc4random \
   arc4random_buf \
+  arc4random_addrandom \
   eventfd \
   epoll_create1 \
   fcntl \
diff --git a/evutil_rand.c b/evutil_rand.c
index 046a14b07..4be0b1c5e 100644
--- a/evutil_rand.c
+++ b/evutil_rand.c
@@ -192,12 +192,14 @@ evutil_secure_rng_get_bytes(void *buf, size_t n)
 	ev_arc4random_buf(buf, n);
 }
 
+#if !defined(EVENT__HAVE_ARC4RANDOM) || defined(EVENT__HAVE_ARC4RANDOM_ADDRANDOM)
 void
 evutil_secure_rng_add_bytes(const char *buf, size_t n)
 {
 	arc4random_addrandom((unsigned char*)buf,
 	    n>(size_t)INT_MAX ? INT_MAX : (int)n);
 }
+#endif
 
 void
 evutil_free_secure_rng_globals_(void)
diff --git a/include/event2/util.h b/include/event2/util.h
index dd4bbb69d..c4af2bd60 100644
--- a/include/event2/util.h
+++ b/include/event2/util.h
@@ -842,6 +842,7 @@ int evutil_secure_rng_init(void);
 EVENT2_EXPORT_SYMBOL
 int evutil_secure_rng_set_urandom_device_file(char *fname);
 
+#ifdef EVENT__HAVE_ARC4RANDOM_ADDRANDOM
 /** Seed the random number generator with extra random bytes.
 
     You should almost never need to call this function; it should be
@@ -858,6 +859,7 @@ int evutil_secure_rng_set_urandom_device_file(char *fname);
  */
 EVENT2_EXPORT_SYMBOL
 void evutil_secure_rng_add_bytes(const char *dat, size_t datlen);
+#endif
 
 #ifdef __cplusplus
 }