146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/*
|
|
* Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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,
|
|
* 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
|
|
* 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_IO_H
|
|
#include <io.h>
|
|
#endif
|
|
#if HAVE_BCRYPT
|
|
#include <windows.h>
|
|
#include <bcrypt.h>
|
|
#endif
|
|
#include <fcntl.h>
|
|
#include <math.h>
|
|
#include <time.h>
|
|
#include <string.h>
|
|
#include "avassert.h"
|
|
#include "internal.h"
|
|
#include "intreadwrite.h"
|
|
#include "timer.h"
|
|
#include "random_seed.h"
|
|
#include "sha.h"
|
|
|
|
#ifndef TEST
|
|
#define TEST 0
|
|
#endif
|
|
|
|
static int read_random(uint32_t *dst, const char *file)
|
|
{
|
|
#if HAVE_UNISTD_H
|
|
int fd = avpriv_open(file, O_RDONLY);
|
|
int err = -1;
|
|
|
|
if (fd == -1)
|
|
return -1;
|
|
err = read(fd, dst, sizeof(*dst));
|
|
close(fd);
|
|
|
|
return err;
|
|
#else
|
|
return -1;
|
|
#endif
|
|
}
|
|
|
|
static uint32_t get_generic_seed(void)
|
|
{
|
|
uint64_t tmp[120/8];
|
|
struct AVSHA *sha = (void*)tmp;
|
|
clock_t last_t = 0;
|
|
clock_t last_td = 0;
|
|
clock_t init_t = 0;
|
|
static uint64_t i = 0;
|
|
static uint32_t buffer[512] = { 0 };
|
|
unsigned char digest[20];
|
|
uint64_t last_i = i;
|
|
|
|
av_assert0(sizeof(tmp) >= av_sha_size);
|
|
|
|
if(TEST){
|
|
memset(buffer, 0, sizeof(buffer));
|
|
last_i = i = 0;
|
|
}else{
|
|
#ifdef AV_READ_TIME
|
|
buffer[13] ^= AV_READ_TIME();
|
|
buffer[41] ^= AV_READ_TIME()>>32;
|
|
#endif
|
|
}
|
|
|
|
for (;;) {
|
|
clock_t t = clock();
|
|
if (last_t + 2*last_td + (CLOCKS_PER_SEC > 1000) >= t) {
|
|
last_td = t - last_t;
|
|
buffer[i & 511] = 1664525*buffer[i & 511] + 1013904223 + (last_td % 3294638521U);
|
|
} else {
|
|
last_td = t - last_t;
|
|
buffer[++i & 511] += last_td % 3294638521U;
|
|
if ((t - init_t) >= CLOCKS_PER_SEC>>5)
|
|
if (last_i && i - last_i > 4 || i - last_i > 64 || TEST && i - last_i > 8)
|
|
break;
|
|
}
|
|
last_t = t;
|
|
if (!init_t)
|
|
init_t = t;
|
|
}
|
|
|
|
if(TEST) {
|
|
buffer[0] = buffer[1] = 0;
|
|
} else {
|
|
#ifdef AV_READ_TIME
|
|
buffer[111] += AV_READ_TIME();
|
|
#endif
|
|
}
|
|
|
|
av_sha_init(sha, 160);
|
|
av_sha_update(sha, (const uint8_t *)buffer, sizeof(buffer));
|
|
av_sha_final(sha, digest);
|
|
return AV_RB32(digest) + AV_RB32(digest + 16);
|
|
}
|
|
|
|
uint32_t av_get_random_seed(void)
|
|
{
|
|
uint32_t seed;
|
|
|
|
#if HAVE_BCRYPT
|
|
BCRYPT_ALG_HANDLE algo_handle;
|
|
NTSTATUS ret = BCryptOpenAlgorithmProvider(&algo_handle, BCRYPT_RNG_ALGORITHM,
|
|
MS_PRIMITIVE_PROVIDER, 0);
|
|
if (BCRYPT_SUCCESS(ret)) {
|
|
NTSTATUS ret = BCryptGenRandom(algo_handle, (UCHAR*)&seed, sizeof(seed), 0);
|
|
BCryptCloseAlgorithmProvider(algo_handle, 0);
|
|
if (BCRYPT_SUCCESS(ret))
|
|
return seed;
|
|
}
|
|
#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))
|
|
return seed;
|
|
return get_generic_seed();
|
|
}
|