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1.1.6

    1: /*
    2:  *  $Id: libnet_prand.c,v 1.1.1.2 2013/07/22 11:54:42 misho 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
   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
   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 */