lib/roken/rand.c

   1 /*
   2  * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33 #include <config.h>
  34
  35 #include "roken.h"
  36
  37 #ifdef HAVE_WIN32_RAND_S
  38 static int hasRand_s = 1;
  39 #endif
  40
  41 void ROKEN_LIB_FUNCTION
  42 rk_random_init(void)
  43 {
  44 #if defined(HAVE_ARC4RANDOM)
  45     arc4random_stir();
  46 #elif defined(HAVE_SRANDOMDEV)
  47     srandomdev();
  48 #elif defined(HAVE_RANDOM)
  49     srandom(time(NULL));
  50 #else
  51 # ifdef HAVE_WIN32_RAND_S
  52     OSVERSIONINFO osInfo;
  53
  54     osInfo.dwOSVersionInfoSize = sizeof(osInfo);
  55     hasRand_s =
  56         (GetVersionEx(&osInfo)
  57           && ((osInfo.dwMajorVersion > 5) ||
  58                (osInfo.dwMajorVersion == 5) && (osInfo.dwMinorVersion >= 1)));
  59 # endif
  60     srand (time(NULL));
  61 #endif
  62 }
  63
  64 #ifdef HAVE_WIN32_RAND_S
  65 unsigned int ROKEN_LIB_FUNCTION
  66 rk_random(void)
  67 {
  68     if (hasRand_s) {
  69         unsigned int n;
  70         int code;
  71
  72         code = rand_s(&n);
  73         if (code == 0)
  74             return n;
  75     }
  76
  77     return rand();
  78 }
  79 #endif