From 5cf24dab9e1d478f795da255d758e886f1129f05 Mon Sep 17 00:00:00 2001
From: Benjamin Drung <bdrung@ubuntu.com>
Date: Tue, 4 Oct 2022 12:13:06 +0200
Subject: [PATCH] Keep evutil_secure_rng_add_bytes

glibc 2.36 on Linux defines `arc4random` and `arc4random_buf` but not
`arc4random_addrandom`. This leads to `evutil_secure_rng_add_bytes` not
being defined.

Use `arc4random_addrandom` from `arc4random.c` in case it is not
defined.

Bug: https://launchpad.net/bugs/1990941
Signed-off-by: Benjamin Drung <bdrung@ubuntu.com>
---
 arc4random.c          |  2 ++
 evutil_rand.c         | 26 +++++++++++++++++++++++---
 include/event2/util.h |  2 --
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/arc4random.c b/arc4random.c
index c9533b17..7b486d65 100644
--- a/arc4random.c
+++ b/arc4random.c
@@ -471,6 +471,7 @@ arc4random(void)
 }
 #endif
 
+#ifndef ARC4RANDOM_NOBUF
 ARC4RANDOM_EXPORT void
 arc4random_buf(void *buf_, size_t n)
 {
@@ -484,6 +485,7 @@ arc4random_buf(void *buf_, size_t n)
 	}
 	ARC4_UNLOCK_();
 }
+#endif
 
 #ifndef ARC4RANDOM_NOUNIFORM
 /*
diff --git a/evutil_rand.c b/evutil_rand.c
index 8e9afdaa..603d65ba 100644
--- a/evutil_rand.c
+++ b/evutil_rand.c
@@ -114,7 +114,29 @@ ev_arc4random_buf(void *buf, size_t n)
 #endif
 }
 
-#else /* !EVENT__HAVE_ARC4RANDOM { */
+#if !defined(EVENT__HAVE_ARC4RANDOM_ADDRANDOM)
+
+#ifdef EVENT__ssize_t
+#define ssize_t EVENT__ssize_t
+#endif
+#define ARC4RANDOM_EXPORT static
+#define ARC4_LOCK_() EVLOCK_LOCK(arc4rand_lock, 0)
+#define ARC4_UNLOCK_() EVLOCK_UNLOCK(arc4rand_lock, 0)
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+static void *arc4rand_lock;
+#endif
+
+#define ARC4RANDOM_UINT32 ev_uint32_t
+#define ARC4RANDOM_NOSTIR
+#define ARC4RANDOM_NORANDOM
+#define ARC4RANDOM_NOUNIFORM
+#define ARC4RANDOM_NOBUF
+
+#include "./arc4random.c"
+
+#endif /* !EVENT__HAVE_ARC4RANDOM_ADDRANDOM */
+
+#else /* !EVENT__HAVE_ARC4RANDON { */
 
 #ifdef EVENT__ssize_t
 #define ssize_t EVENT__ssize_t
@@ -190,14 +212,12 @@ 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 43955bf6..62f142c6 100644
--- a/include/event2/util.h
+++ b/include/event2/util.h
@@ -862,7 +862,6 @@ int evutil_secure_rng_init(void);
 EVENT2_EXPORT_SYMBOL
 int evutil_secure_rng_set_urandom_device_file(char *fname);
 
-#if !defined(EVENT__HAVE_ARC4RANDOM) || defined(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
@@ -879,7 +878,6 @@ 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
 }
-- 
2.37.2