[FFmpeg-devel] [PATCH 1/2] avformat/hlsenc: fall back to av_get_random_seed() when generating AES128 key

[Marton Balint]

It should be OK to use av_get_random_seed() to generate the key instead of
using openSSL/Gcrypt functions. This removes the hard dependancy of those libs
for key generation functionality.

Fixes ticket #10441.

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 libavformat/hlsenc.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index 1e0848ce3d..0b22c71186 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -40,6 +40,7 @@
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"
 #include "libavutil/log.h"
+#include "libavutil/random_seed.h"
 #include "libavutil/time.h"
 #include "libavutil/time_internal.h"
 
@@ -710,18 +711,18 @@ fail:
     return ret;
 }
 
-static int randomize(uint8_t *buf, int len)
+static void randomize(uint8_t *buf, int len)
 {
 #if CONFIG_GCRYPT
     gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
-    return 0;
+    return;
 #elif CONFIG_OPENSSL
     if (RAND_bytes(buf, len))
-        return 0;
-#else
-    return AVERROR(ENOSYS);
+        return;
 #endif
-    return AVERROR(EINVAL);
+    av_assert0(len % 4 == 0);
+    for (int i = 0; i < len; i += 4)
+        AV_WB32(buf + i, av_get_random_seed());
 }
 
 static int do_encrypt(AVFormatContext *s, VariantStream *vs)
@@ -775,10 +776,7 @@ static int do_encrypt(AVFormatContext *s, VariantStream *vs)
     if (!*hls->key_string) {
         AVDictionary *options = NULL;
         if (!hls->key) {
-            if ((ret = randomize(key, sizeof(key))) < 0) {
-                av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
-                return ret;
-            }
+            randomize(key, sizeof(key));
         } else {
             memcpy(key, hls->key, sizeof(key));
         }
-- 
2.35.3