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| author | Ganesh Ajjanagadde <gajjanagadde@gmail.com> | 2015-12-06 21:10:21 -0500 |
|---|---|---|
| committer | Ganesh Ajjanagadde <gajjanagadde@gmail.com> | 2015-12-17 08:12:41 -0800 |
| commit | 39f8c7961dcd530e88d13c600145097106647d2e (patch) | |
| tree | 0519a50d0ca6c71a57b98525a3b8ef0bd74bf244 | |
| parent | 7b880464cb31b779259d56123e03cf3903d476e5 (diff) | |
| download | ffmpeg-39f8c7961dcd530e88d13c600145097106647d2e.tar.gz | |
lavu/random_seed: use arc4random() when available
arc4random() was designed as a superior interface for system random
number generation, designed for OpenBSD and subsequently incorporated by
other BSD's, Mac OS X, and some non-standard libc's. It is thus an improvement to
use it whenever available.
As a side note, this may or may not get included in glibc, and there is
a proposal to create a posix_random family based on these ideas:
http://austingroupbugs.net/view.php?id=859.
Tested on Mac OS X.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
| -rwxr-xr-x | configure | 2 | ||||
| -rw-r--r-- | libavutil/random_seed.c | 4 |
2 files changed, 6 insertions, 0 deletions
@@ -1841,6 +1841,7 @@ MATH_FUNCS=" SYSTEM_FUNCS=" access aligned_malloc + arc4random clock_gettime closesocket CommandLineToArgvW @@ -5232,6 +5233,7 @@ check_func ${malloc_prefix}memalign && enable memalign check_func ${malloc_prefix}posix_memalign && enable posix_memalign check_func access +check_func arc4random check_func_headers time.h clock_gettime || { check_func_headers time.h clock_gettime -lrt && add_extralibs -lrt && LIBRT="-lrt"; } check_func fcntl check_func fork diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c index 8aa8c3879b..205a636f92 100644 --- a/libavutil/random_seed.c +++ b/libavutil/random_seed.c @@ -121,6 +121,10 @@ uint32_t av_get_random_seed(void) } #endif +#if HAVE_ARC4RANDOM + return arc4random(); +#endif + if (read_random(&seed, "/dev/urandom") == sizeof(seed)) return seed; if (read_random(&seed, "/dev/random") == sizeof(seed)) |