/*
* Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* 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 "internal.h"
#include "timer.h"
#include "random_seed.h"
-#include "avutil.h"
static int read_random(uint32_t *dst, const char *file)
{
- int fd = open(file, O_RDONLY);
+#if HAVE_UNISTD_H
+ int fd = avpriv_open(file, O_RDONLY);
int err = -1;
if (fd == -1)
close(fd);
return err;
+#else
+ return -1;
+#endif
}
-uint32_t av_get_random_seed(void)
+static uint32_t get_generic_seed(void)
{
- uint32_t seed;
- int err;
-
- err = read_random(&seed, "/dev/urandom");
- if (err != sizeof(seed))
- err = read_random(&seed, "/dev/random");
- if (err == sizeof(seed))
- return seed;
+ clock_t last_t = 0;
+ int bits = 0;
+ uint64_t random = 0;
+ unsigned i;
+ 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);
+ bits++;
+ }
+ }
+ last_t = t;
+ }
#ifdef AV_READ_TIME
- seed = AV_READ_TIME();
+ random ^= AV_READ_TIME();
+#else
+ random ^= clock();
#endif
- // XXX what to do ?
- return seed;
+
+ random += random >> 32;
+
+ return random;
}
-#if LIBAVUTIL_VERSION_MAJOR < 51
-attribute_deprecated uint32_t ff_random_get_seed(void);
-uint32_t ff_random_get_seed(void)
+uint32_t av_get_random_seed(void)
{
- return av_get_random_seed();
-}
+ 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();
+}