/src/suricata7/src/util-random.c
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1 | | /* Copyright (C) 2007-2017 Open Information Security Foundation |
2 | | * |
3 | | * You can copy, redistribute or modify this Program under the terms of |
4 | | * the GNU General Public License version 2 as published by the Free |
5 | | * Software Foundation. |
6 | | * |
7 | | * This program is distributed in the hope that it will be useful, |
8 | | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
9 | | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
10 | | * GNU General Public License for more details. |
11 | | * |
12 | | * You should have received a copy of the GNU General Public License |
13 | | * version 2 along with this program; if not, write to the Free Software |
14 | | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
15 | | * 02110-1301, USA. |
16 | | */ |
17 | | |
18 | | /** |
19 | | * \file |
20 | | * |
21 | | * \author Victor Julien <victor@inliniac.net> |
22 | | * |
23 | | * Functions for getting a random value based on |
24 | | * SEI CERT C Coding Standard MSC30-C |
25 | | */ |
26 | | |
27 | | #include "suricata-common.h" |
28 | | #include "suricata.h" |
29 | | #include "util-random.h" |
30 | | #include "util-debug.h" |
31 | | |
32 | | #if !(defined(HAVE_WINCRYPT_H) && defined(OS_WIN32)) |
33 | | #if defined(HAVE_CLOCK_GETTIME) |
34 | | |
35 | | static long int RandomGetClock(void) |
36 | 0 | { |
37 | 0 | struct timespec ts; |
38 | 0 | clock_gettime(CLOCK_REALTIME, &ts); |
39 | | |
40 | | // coverity[dont_call : FALSE] |
41 | 0 | srandom(ts.tv_nsec ^ ts.tv_sec); |
42 | 0 | long int value = random(); |
43 | 0 | return value; |
44 | 0 | } |
45 | | |
46 | | #else |
47 | | |
48 | | static long int RandomGetPosix(void) |
49 | | { |
50 | | struct timeval tv; |
51 | | memset(&tv, 0, sizeof(tv)); |
52 | | gettimeofday(&tv, NULL); |
53 | | |
54 | | // coverity[dont_call : FALSE] |
55 | | srandom(tv.tv_usec ^ tv.tv_sec); |
56 | | long int value = random(); |
57 | | return value; |
58 | | } |
59 | | |
60 | | #endif |
61 | | #endif /* !(defined(HAVE_WINCRYPT_H) && defined(OS_WIN32)) */ |
62 | | |
63 | | #if defined(HAVE_WINCRYPT_H) && defined(OS_WIN32) |
64 | | #include <wincrypt.h> |
65 | | |
66 | | long int RandomGet(void) |
67 | | { |
68 | | if (g_disable_randomness) |
69 | | return 0; |
70 | | |
71 | | HCRYPTPROV p; |
72 | | if (!CryptAcquireContext(&p, NULL, NULL, PROV_RSA_FULL, 0)) { |
73 | | DWORD err = GetLastError(); |
74 | | SCLogDebug("CryptAcquireContext error: %" PRIu32, (uint32_t)err); |
75 | | if (err == (DWORD)NTE_BAD_KEYSET) { |
76 | | /* The key doesn't exist yet, create it */ |
77 | | if (!CryptAcquireContext(&p, NULL, NULL, PROV_RSA_FULL, |
78 | | CRYPT_NEWKEYSET)) { |
79 | | |
80 | | SCLogDebug("CryptAcquireContext error: %" PRIu32, |
81 | | (uint32_t)err); |
82 | | return -1; |
83 | | } |
84 | | } else { |
85 | | return -1; |
86 | | } |
87 | | } |
88 | | |
89 | | long int value = 0; |
90 | | if (!CryptGenRandom(p, sizeof(value), (BYTE *)&value)) { |
91 | | (void)CryptReleaseContext(p, 0); |
92 | | return -1; |
93 | | } |
94 | | |
95 | | (void)CryptReleaseContext(p, 0); |
96 | | |
97 | | return value; |
98 | | } |
99 | | #elif defined(HAVE_GETRANDOM) |
100 | | long int RandomGet(void) |
101 | 22.8k | { |
102 | 22.8k | if (g_disable_randomness) |
103 | 22.8k | return 0; |
104 | | |
105 | 0 | long int value = 0; |
106 | 0 | int ret = getrandom(&value, sizeof(value), 0); |
107 | | /* ret should be sizeof(value), but if it is > 0 and < sizeof(value) |
108 | | * it's still better than nothing so we return what we have */ |
109 | 0 | if (ret <= 0) { |
110 | 0 | if (ret == -1 && errno == ENOSYS) { |
111 | 0 | #if defined(HAVE_CLOCK_GETTIME) |
112 | 0 | return RandomGetClock(); |
113 | | #else |
114 | | return RandomGetPosix(); |
115 | | #endif |
116 | 0 | } |
117 | 0 | return -1; |
118 | 0 | } |
119 | 0 | return value; |
120 | 0 | } |
121 | | #elif defined(HAVE_CLOCK_GETTIME) |
122 | | long int RandomGet(void) |
123 | | { |
124 | | if (g_disable_randomness) |
125 | | return 0; |
126 | | |
127 | | return RandomGetClock(); |
128 | | } |
129 | | #else |
130 | | long int RandomGet(void) |
131 | | { |
132 | | if (g_disable_randomness) |
133 | | return 0; |
134 | | |
135 | | return RandomGetPosix(); |
136 | | } |
137 | | #endif |