sal/osl/w32/random.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #if !defined _CRT_RAND_S
  11 #define _CRT_RAND_S
  12 #endif
  13
  14 #include <stdlib.h>
  15 #include <memory.h>
  16
  17 #include <oslrandom.h>
  18
  19 int osl_get_system_random_data(char* buffer, size_t desired_len)
  20 {
  21     unsigned int val;
  22
  23     /* if unaligned fill to alignment */
  24     if(reinterpret_cast<uintptr_t>(buffer) & 3)
  25     {
  26         size_t len = 4 - (reinterpret_cast<size_t>(buffer) & 3);
  27
  28         if(len > desired_len)
  29         {
  30             len = desired_len;
  31         }
  32         if(rand_s(&val))
  33         {
  34             return 0;
  35         }
  36         memcpy(buffer, &val, len);
  37         buffer += len;
  38         desired_len -= len;
  39     }
  40     /* fill directly into the buffer as long as we can */
  41     while(desired_len >= 4)
  42     {
  43         if(rand_s(reinterpret_cast<unsigned int*>(buffer)))
  44         {
  45             return 0;
  46         }
  47         else
  48         {
  49             buffer += 4;
  50             desired_len -= 4;
  51         }
  52     }
  53     /* deal with the partial int reminder to fill */
  54     if(desired_len)
  55     {
  56         if(rand_s(&val))
  57         {
  58             return 0;
  59         }
  60         memcpy(buffer, &val, desired_len);
  61     }
  62     return 1;
  63 }
  64
  65
  66 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */