FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavutil/random_seed.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 41 48 85.4%
Functions: 4 4 100.0%
Branches: 15 24 62.5%
Line Branch Exec Source
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 #if CONFIG_GCRYPT
34 #include <gcrypt.h>
35 #elif CONFIG_OPENSSL
36 #include <openssl/rand.h>
37 #endif
38 #include <fcntl.h>
39 #include <math.h>
40 #include <time.h>
41 #include <string.h>
42 #include "avassert.h"
43 #include "file_open.h"
44 #include "internal.h"
45 #include "intreadwrite.h"
46 #include "timer.h"
47 #include "random_seed.h"
48 #include "sha.h"
49
50 #ifndef TEST
51 #define TEST 0
52 #endif
53
54 370 static int read_random(uint8_t *dst, size_t len, const char *file)
55 {
56 #if HAVE_UNISTD_H
57 370 FILE *fp = avpriv_fopen_utf8(file, "r");
58 size_t err;
59
60
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 370 if (!fp)
61 ✗ return AVERROR_UNKNOWN;
62 370 setvbuf(fp, NULL, _IONBF, 0);
63 370 err = fread(dst, 1, len, fp);
64 370 fclose(fp);
65
66
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 370 if (err != len)
67 ✗ return AVERROR_UNKNOWN;
68
69 370 return 0;
70 #else
71 return AVERROR(ENOSYS);
72 #endif
73 }
74
75 256 static uint32_t get_generic_seed(void)
76 {
77 uint64_t tmp[120/8];
78 256 struct AVSHA *sha = (void*)tmp;
79 256 clock_t last_t = 0;
80 256 clock_t last_td = 0;
81 256 clock_t init_t = 0;
82 static uint64_t i = 0;
83 static uint32_t buffer[512] = { 0 };
84 unsigned char digest[20];
85 256 uint64_t last_i = i;
86
87
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 256 av_assert0(sizeof(tmp) >= av_sha_size);
88
89 if(TEST){
90 256 memset(buffer, 0, sizeof(buffer));
91 256 last_i = i = 0;
92 }else{
93 #ifdef AV_READ_TIME
94 ✗ buffer[13] ^= AV_READ_TIME();
95 ✗ buffer[41] ^= AV_READ_TIME()>>32;
96 #endif
97 }
98
99 21265727 for (;;) {
100 21265983 clock_t t = clock();
101
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 21265983 if (last_t + 2*last_td + (CLOCKS_PER_SEC > 1000) >= t) {
102 21263641 last_td = t - last_t;
103 21263641 buffer[i & 511] = 1664525*buffer[i & 511] + 1013904223 + (last_td % 3294638521U);
104 } else {
105 2342 last_td = t - last_t;
106 2342 buffer[++i & 511] += last_td % 3294638521U;
107
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 2342 if ((t - init_t) >= CLOCKS_PER_SEC>>5)
108
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 1419 if (last_i && i - last_i > 4 || i - last_i > 64 || TEST && i - last_i > 8)
109 break;
110 }
111 21265727 last_t = t;
112
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 21265727 if (!init_t)
113 256 init_t = t;
114 }
115
116 if(TEST) {
117 256 buffer[0] = buffer[1] = 0;
118 } else {
119 #ifdef AV_READ_TIME
120 ✗ buffer[111] += AV_READ_TIME();
121 #endif
122 }
123
124 256 av_sha_init(sha, 160);
125 256 av_sha_update(sha, (const uint8_t *)buffer, sizeof(buffer));
126 256 av_sha_final(sha, digest);
127 256 return AV_RB32(digest) + AV_RB32(digest + 16);
128 }
129
130 370 int av_random_bytes(uint8_t* buf, size_t len)
131 {
132 int err;
133
134 #if HAVE_BCRYPT
135 BCRYPT_ALG_HANDLE algo_handle;
136 NTSTATUS ret = BCryptOpenAlgorithmProvider(&algo_handle, BCRYPT_RNG_ALGORITHM,
137 MS_PRIMITIVE_PROVIDER, 0);
138 if (BCRYPT_SUCCESS(ret)) {
139 NTSTATUS ret = BCryptGenRandom(algo_handle, (PUCHAR)buf, len, 0);
140 BCryptCloseAlgorithmProvider(algo_handle, 0);
141 if (BCRYPT_SUCCESS(ret))
142 return 0;
143 }
144 #endif
145
146 #if HAVE_ARC4RANDOM_BUF
147 arc4random_buf(buf, len);
148 return 0;
149 #endif
150
151 370 err = read_random(buf, len, "/dev/urandom");
152
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 370 if (!err)
153 370 return err;
154
155 #if CONFIG_GCRYPT
156 gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
157 return 0;
158 #elif CONFIG_OPENSSL
159 if (RAND_bytes(buf, len) == 1)
160 return 0;
161 return AVERROR_EXTERNAL;
162 #else
163 ✗ return err;
164 #endif
165 }
166
167 370 uint32_t av_get_random_seed(void)
168 {
169 uint32_t seed;
170
171
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 370 if (av_random_bytes((uint8_t *)&seed, sizeof(seed)) < 0)
172 ✗ return get_generic_seed();
173
174 370 return seed;
175 }
176