src/base/utils/randomlayer_win.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2024  Mike Tzou (Chocobo1)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  */
  28
  29 #include <limits>
  30
  31 #include <windows.h>
  32
  33 #include <QtLogging>
  34
  35 #include "base/global.h"
  36 #include "base/utils/os.h"
  37
  38 namespace
  39 {
  40     class RandomLayer
  41     {
  42     // need to satisfy UniformRandomBitGenerator requirements
  43     public:
  44         using result_type = uint32_t;
  45
  46         RandomLayer()
  47             : m_processPrng {Utils::OS::loadWinAPI<PPROCESSPRNG>(u"BCryptPrimitives.dll"_s, "ProcessPrng")}
  48         {
  49             if (!m_processPrng)
  50                 qFatal("Failed to load ProcessPrng().");
  51         }
  52
  53         static constexpr result_type min()
  54         {
  55             return std::numeric_limits<result_type>::min();
  56         }
  57
  58         static constexpr result_type max()
  59         {
  60             return std::numeric_limits<result_type>::max();
  61         }
  62
  63         result_type operator()()
  64         {
  65             result_type buf = 0;
  66             const bool result = m_processPrng(reinterpret_cast<PBYTE>(&buf), sizeof(buf));
  67             if (!result)
  68                 qFatal("ProcessPrng() failed.");
  69
  70             return buf;
  71         }
  72
  73     private:
  74         using PPROCESSPRNG = BOOL (WINAPI *)(PBYTE, SIZE_T);
  75         const PPROCESSPRNG m_processPrng = nullptr;
  76     };
  77 }