FFmpeg  4.3
random_seed.c
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1 /*
2  * Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config.h"
22 
23 #if HAVE_UNISTD_H
24 #include <unistd.h>
25 #endif
26 #if HAVE_IO_H
27 #include <io.h>
28 #endif
29 #if HAVE_BCRYPT
30 #include <windows.h>
31 #include <bcrypt.h>
32 #endif
33 #include <fcntl.h>
34 #include <math.h>
35 #include <time.h>
36 #include <string.h>
37 #include "avassert.h"
38 #include "internal.h"
39 #include "intreadwrite.h"
40 #include "timer.h"
41 #include "random_seed.h"
42 #include "sha.h"
43 
44 #ifndef TEST
45 #define TEST 0
46 #endif
47 
48 static int read_random(uint32_t *dst, const char *file)
49 {
50 #if HAVE_UNISTD_H
51  int fd = avpriv_open(file, O_RDONLY);
52  int err = -1;
53 
54  if (fd == -1)
55  return -1;
56  err = read(fd, dst, sizeof(*dst));
57  close(fd);
58 
59  return err;
60 #else
61  return -1;
62 #endif
63 }
64 
65 static uint32_t get_generic_seed(void)
66 {
67  uint64_t tmp[120/8];
68  struct AVSHA *sha = (void*)tmp;
69  clock_t last_t = 0;
70  clock_t last_td = 0;
71  clock_t init_t = 0;
72  static uint64_t i = 0;
73  static uint32_t buffer[512] = { 0 };
74  unsigned char digest[20];
75  uint64_t last_i = i;
76 
77  av_assert0(sizeof(tmp) >= av_sha_size);
78 
79  if(TEST){
80  memset(buffer, 0, sizeof(buffer));
81  last_i = i = 0;
82  }else{
83 #ifdef AV_READ_TIME
84  buffer[13] ^= AV_READ_TIME();
85  buffer[41] ^= AV_READ_TIME()>>32;
86 #endif
87  }
88 
89  for (;;) {
90  clock_t t = clock();
91  if (last_t + 2*last_td + (CLOCKS_PER_SEC > 1000) >= t) {
92  last_td = t - last_t;
93  buffer[i & 511] = 1664525*buffer[i & 511] + 1013904223 + (last_td % 3294638521U);
94  } else {
95  last_td = t - last_t;
96  buffer[++i & 511] += last_td % 3294638521U;
97  if ((t - init_t) >= CLOCKS_PER_SEC>>5)
98  if (last_i && i - last_i > 4 || i - last_i > 64 || TEST && i - last_i > 8)
99  break;
100  }
101  last_t = t;
102  if (!init_t)
103  init_t = t;
104  }
105 
106  if(TEST) {
107  buffer[0] = buffer[1] = 0;
108  } else {
109 #ifdef AV_READ_TIME
110  buffer[111] += AV_READ_TIME();
111 #endif
112  }
113 
114  av_sha_init(sha, 160);
115  av_sha_update(sha, (const uint8_t *)buffer, sizeof(buffer));
116  av_sha_final(sha, digest);
117  return AV_RB32(digest) + AV_RB32(digest + 16);
118 }
119 
120 uint32_t av_get_random_seed(void)
121 {
122  uint32_t seed;
123 
124 #if HAVE_BCRYPT
125  BCRYPT_ALG_HANDLE algo_handle;
126  NTSTATUS ret = BCryptOpenAlgorithmProvider(&algo_handle, BCRYPT_RNG_ALGORITHM,
127  MS_PRIMITIVE_PROVIDER, 0);
128  if (BCRYPT_SUCCESS(ret)) {
129  NTSTATUS ret = BCryptGenRandom(algo_handle, (UCHAR*)&seed, sizeof(seed), 0);
130  BCryptCloseAlgorithmProvider(algo_handle, 0);
131  if (BCRYPT_SUCCESS(ret))
132  return seed;
133  }
134 #endif
135 
136 #if HAVE_ARC4RANDOM
137  return arc4random();
138 #endif
139 
140  if (read_random(&seed, "/dev/urandom") == sizeof(seed))
141  return seed;
142  if (read_random(&seed, "/dev/random") == sizeof(seed))
143  return seed;
144  return get_generic_seed();
145 }
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:26
av_sha_init
av_cold int av_sha_init(AVSHA *ctx, int bits)
Initialize SHA-1 or SHA-2 hashing.
Definition: sha.c:273
TEST
#define TEST
Definition: random_seed.c:45
av_get_random_seed
uint32_t av_get_random_seed(void)
Get a seed to use in conjunction with random functions.
Definition: random_seed.c:120
U
#define U(x)
Definition: vp56_arith.h:37
avassert.h
intreadwrite.h
avpriv_open
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
av_sha_final
void av_sha_final(AVSHA *ctx, uint8_t *digest)
Finish hashing and output digest value.
Definition: sha.c:345
av_sha_size
const int av_sha_size
Definition: sha.c:43
sha.h
timer.h
time.h
seed
static unsigned int seed
Definition: videogen.c:78
AV_RB32
#define AV_RB32
Definition: intreadwrite.h:130
av_sha_update
void av_sha_update(struct AVSHA *ctx, const uint8_t *data, unsigned int len)
Update hash value.
Definition: sha.c:315
AV_READ_TIME
#define AV_READ_TIME
Definition: timer.h:26
read_random
static int read_random(uint32_t *dst, const char *file)
Definition: random_seed.c:48
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
internal.h
uint8_t
uint8_t
Definition: audio_convert.c:194
AVSHA
hash context
Definition: sha.c:34
ret
ret
Definition: filter_design.txt:187
file
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration file
Definition: fate.txt:125
random_seed.h
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
config.h
get_generic_seed
static uint32_t get_generic_seed(void)
Definition: random_seed.c:65