diff options
Diffstat (limited to 'ffmpeg/libavutil/random_seed.c')
| -rw-r--r-- | ffmpeg/libavutil/random_seed.c | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/ffmpeg/libavutil/random_seed.c b/ffmpeg/libavutil/random_seed.c deleted file mode 100644 index aa89024..0000000 --- a/ffmpeg/libavutil/random_seed.c +++ /dev/null @@ -1,152 +0,0 @@ -/* - * 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_CRYPTGENRANDOM -#include <windows.h> -#include <wincrypt.h> -#endif -#include <fcntl.h> -#include <math.h> -#include <time.h> -#include <string.h> -#include "avassert.h" -#include "internal.h" -#include "timer.h" -#include "random_seed.h" -#include "sha.h" -#include "intreadwrite.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) -{ - uint8_t tmp[120]; - struct AVSHA *sha = (void*)tmp; - clock_t last_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 == t){ - buffer[i&511]++; - }else{ - buffer[++i&511]+= (t-last_t) % 3294638521U; - if(last_i && i-last_i > 4 || i-last_i > 64 || TEST && i-last_i > 8) - break; - } - last_t = t; - } - - if(TEST) - buffer[0] = buffer[1] = 0; - - av_sha_init(sha, 160); - av_sha_update(sha, (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_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 TEST -#undef printf -#define N 256 -#include <stdio.h> - -int main(void) -{ - int i, j, retry; - uint32_t seeds[N]; - - for (retry=0; retry<3; retry++){ - for (i=0; i<N; i++){ - seeds[i] = av_get_random_seed(); - for (j=0; j<i; j++) - if (seeds[j] == seeds[i]) - goto retry; - } - printf("seeds OK\n"); - return 0; - retry:; - } - printf("FAIL at %d with %X\n", j, seeds[j]); - return 1; -} -#endif |
