X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Frandom_seed.c;h=ec9caa74b709ce37ce14b7af8f8984cda3e2ec03;hb=932117171f32fc3160f3d92943290238945fcb28;hp=6dc8d22ca4fc608f5ce6ec8b1af59ab560e03115;hpb=2912e87a6c9264d556734e2bf94a99c64cf9b102;p=ffmpeg

diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c
index 6dc8d22ca4f..ec9caa74b70 100644
--- a/libavutil/random_seed.c
+++ b/libavutil/random_seed.c
@@ -18,15 +18,24 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "config.h"
+
+#if HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#if HAVE_CRYPTGENRANDOM
+#include <windows.h>
+#include <wincrypt.h>
+#endif
 #include <fcntl.h>
+#include <math.h>
+#include <time.h>
 #include "timer.h"
-#include "time.h"
 #include "random_seed.h"
-#include "avutil.h"
 
 static int read_random(uint32_t *dst, const char *file)
 {
+#if HAVE_UNISTD_H
     int fd = open(file, O_RDONLY);
     int err = -1;
 
@@ -36,28 +45,31 @@ static int read_random(uint32_t *dst, const char *file)
     close(fd);
 
     return err;
+#else
+    return -1;
+#endif
 }
 
 static uint32_t get_generic_seed(void)
 {
-    clock_t last_t=0;
-    int bits=0;
-    uint64_t random=0;
+    clock_t last_t  = 0;
+    int bits        = 0;
+    uint64_t random = 0;
     unsigned i;
-    float s=0.000000000001;
+    float s = 0.000000000001;
 
-    for(i=0;bits<64;i++){
-        clock_t t= clock();
-        if(last_t && fabs(t-last_t)>s || t==(clock_t)-1){
-            if(i<10000 && s<(1<<24)){
-                s+=s;
-                i=t=0;
-            }else{
-                random= 2*random + (i&1);
+    for (i = 0; bits < 64; i++) {
+        clock_t t = clock();
+        if (last_t && fabs(t - last_t) > s || t == (clock_t) -1) {
+            if (i < 10000 && s < (1 << 24)) {
+                s += s;
+                i = t = 0;
+            } else {
+                random = 2 * random + (i & 1);
                 bits++;
             }
         }
-        last_t= t;
+        last_t = t;
     }
 #ifdef AV_READ_TIME
     random ^= AV_READ_TIME();
@@ -65,7 +77,7 @@ static uint32_t get_generic_seed(void)
     random ^= clock();
 #endif
 
-    random += random>>32;
+    random += random >> 32;
 
     return random;
 }
@@ -74,17 +86,20 @@ uint32_t av_get_random_seed(void)
 {
     uint32_t seed;
 
+#if HAVE_CRYPTGENRANDOM
+    HCRYPTPROV provider;
+    if (CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
+                            CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
+        BOOL ret = CryptGenRandom(provider, sizeof(seed), (PBYTE) &seed);
+        CryptReleaseContext(provider, 0);
+        if (ret)
+            return seed;
+    }
+#endif
+
     if (read_random(&seed, "/dev/urandom") == sizeof(seed))
         return seed;
     if (read_random(&seed, "/dev/random")  == sizeof(seed))
         return seed;
     return get_generic_seed();
 }
-
-#if LIBAVUTIL_VERSION_MAJOR < 51
-attribute_deprecated uint32_t ff_random_get_seed(void);
-uint32_t ff_random_get_seed(void)
-{
-    return av_get_random_seed();
-}
-#endif