qBittorrent/src/base/utils/randomlayer_other.cpp
Chocobo1 f51ad39ad9
Add fallback for random number generator
`getrandom()` is available since Linux 3.17 (2014/10/05) yet there are older devices that don't
meet this requirement.

Closes #22691.
PR #22723.
2025-05-18 12:40:49 +03:00

79 lines
2.5 KiB
C++

/*
* Bittorrent Client using Qt and libtorrent.
* Copyright (C) 2024 Mike Tzou (Chocobo1)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* In addition, as a special exception, the copyright holders give permission to
* link this program with the OpenSSL project's "OpenSSL" library (or with
* modified versions of it that use the same license as the "OpenSSL" library),
* and distribute the linked executables. You must obey the GNU General Public
* License in all respects for all of the code used other than "OpenSSL". If you
* modify file(s), you may extend this exception to your version of the file(s),
* but you are not obligated to do so. If you do not wish to do so, delete this
* exception statement from your version.
*/
#include <limits>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <QtLogging>
namespace
{
class RandomLayer
{
// need to satisfy UniformRandomBitGenerator requirements
public:
using result_type = uint32_t;
RandomLayer()
: m_randDev {fopen("/dev/urandom", "rb")}
{
if (!m_randDev)
qFatal("Failed to open /dev/urandom. Reason: \"%s\". Error code: %d.", std::strerror(errno), errno);
}
~RandomLayer()
{
fclose(m_randDev);
}
static constexpr result_type min()
{
return std::numeric_limits<result_type>::min();
}
static constexpr result_type max()
{
return std::numeric_limits<result_type>::max();
}
result_type operator()() const
{
result_type buf = 0;
if (fread(&buf, sizeof(buf), 1, m_randDev) == 1)
return buf;
qFatal("Read /dev/urandom error. Reason: \"%s\". Error code: %d.", std::strerror(errno), errno);
}
private:
FILE *m_randDev = nullptr;
};
}