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/*
* libnet
* libnet_prand.c - pseudo-random number generation
*
* Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include "common.h"
#ifdef _WIN32
#include <wincrypt.h>
#include <time.h>
#else
#include <sys/time.h> /* gettimeofday() */
#endif
int
libnet_seed_prand(libnet_t *l)
{
#ifndef WIN32
struct timeval seed;
#endif
if (l == NULL)
{
return (-1);
}
#ifdef WIN32
srand((unsigned)time(NULL));
#else
if (gettimeofday(&seed, NULL) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
"%s(): cannot gettimeofday", __func__);
return (-1);
}
/*
* More entropy then just seeding with time(2).
*/
srandom((unsigned)(seed.tv_sec ^ seed.tv_usec));
#endif
return (1);
}
/* FIXME this code makes no sense. On unix we use random(), which
* is intended to have no security, and under win32 we use cryptographically
* strong entropy source? If necessary, why aren't we using /dev/random
* on unix? What's going on here?
*/
uint32_t
libnet_get_prand(int mod)
{
uint32_t n; /* 0 to 4,294,967,295 */
#ifndef WIN32
n = random();
#else
HCRYPTPROV hProv = 0;
CryptAcquireContext(&hProv,
0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
CryptGenRandom(hProv, sizeof(n), (BYTE*)&n);
CryptReleaseContext(hProv, 0);
#endif
switch (mod)
{
case LIBNET_PR2:
return (n % 0x2); /* 0 - 1 */
case LIBNET_PR8:
return (n % 0xff); /* 0 - 255 */
case LIBNET_PR16:
return (n % 0x7fff); /* 0 - 32767 */
case LIBNET_PRu16:
return (n % 0xffff); /* 0 - 65535 */
case LIBNET_PR32:
return (n % 0x7fffffff); /* 0 - 2147483647 */
case LIBNET_PRu32:
return (n); /* 0 - 4294967295 */
}
return (0); /* NOTTREACHED */
}
/* EOF */
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