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 #define _CRT_RAND_S
  11
  12 #include <stdlib.h>
  13 #include <memory.h>
  14
  15 #include <oslrandom.h>
  16
  17 int osl_get_system_random_data(char* buffer, size_t desired_len)
  18 {
  19     unsigned int val;
  20
  21     /* if unaligned fill to alignment */
  22     if (reinterpret_cast<uintptr_t>(buffer) & 3)
  23     {
  24         size_t len = 4 - (reinterpret_cast<size_t>(buffer) & 3);
  25
  26         if (len > desired_len)
  27         {
  28             len = desired_len;
  29         }
  30         if (rand_s(&val))
  31         {
  32             return 0;
  33         }
  34         memcpy(buffer, &val, len);
  35         buffer += len;
  36         desired_len -= len;
  37     }
  38     /* fill directly into the buffer as long as we can */
  39     while (desired_len >= 4)
  40     {
  41         if (rand_s(reinterpret_cast<unsigned int*>(buffer)))
  42         {
  43             return 0;
  44         }
  45         else
  46         {
  47             buffer += 4;
  48             desired_len -= 4;
  49         }
  50     }
  51     /* deal with the partial int reminder to fill */
  52     if (desired_len)
  53     {
  54         if (rand_s(&val))
  55         {
  56             return 0;
  57         }
  58         memcpy(buffer, &val, desired_len);
  59     }
  60     return 1;
  61 }
  62
  63 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */