1 /*
2 * $Id: libnet_prand.c,v 1.7 2004/01/28 19:45:00 mike Exp $
3 *
4 * libnet
5 * libnet_prand.c - pseudo-random number generation
6 *
7 * Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 */
32
33 #if (HAVE_CONFIG_H)
34 #include "../include/config.h"
35 #endif
36 #if (!(_WIN32) || (__CYGWIN__))
37 #include "../include/libnet.h"
38 #else
39 #include "../include/win32/libnet.h"
40 #endif
41 int
libnet_seed_prand(libnet_t * l)42 libnet_seed_prand(libnet_t *l)
43 {
44 #if !(__WIN32__)
45 struct timeval seed;
46 #endif
47
48 if (l == NULL)
49 {
50 return (-1);
51 }
52
53 #if __WIN32__
54 srand((unsigned)time(NULL));
55 #else
56 if (gettimeofday(&seed, NULL) == -1)
57 {
58 snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
59 "%s(): cannot gettimeofday\n", __func__);
60 return (-1);
61 }
62
63 /*
64 * More entropy then just seeding with time(2).
65 */
66 srandom((unsigned)(seed.tv_sec ^ seed.tv_usec));
67 #endif
68 return (1);
69 }
70
71
72 uint32_t
libnet_get_prand(int mod)73 libnet_get_prand(int mod)
74 {
75 uint32_t n; /* 0 to 4,294,967,295 */
76 #ifndef _WIN32
77 n = random();
78 #else
79 HCRYPTPROV hProv = 0;
80 CryptAcquireContext(&hProv,
81 0, 0, PROV_RSA_FULL,
82 CRYPT_VERIFYCONTEXT);
83
84 CryptGenRandom(hProv,
85 sizeof(n), (BYTE*)&n);
86 CryptReleaseContext(hProv, 0);
87 #endif
88 switch (mod)
89 {
90 case LIBNET_PR2:
91 return (n % 0x2); /* 0 - 1 */
92 case LIBNET_PR8:
93 return (n % 0xff); /* 0 - 255 */
94 case LIBNET_PR16:
95 return (n % 0x7fff); /* 0 - 32767 */
96 case LIBNET_PRu16:
97 return (n % 0xffff); /* 0 - 65535 */
98 case LIBNET_PR32:
99 return (n % 0x7fffffff); /* 0 - 2147483647 */
100 case LIBNET_PRu32:
101 return (n); /* 0 - 4294967295 */
102 }
103 return (0); /* NOTTREACHED */
104 }
105
106 /* EOF */
107