ClickHouse/contrib/libpoco/Foundation/src/RandomStream.cpp

130 lines
2.3 KiB
C++

//
// RandomStream.cpp
//
// $Id: //poco/1.4/Foundation/src/RandomStream.cpp#1 $
//
// Library: Foundation
// Package: Crypt
// Module: RandomStream
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/RandomStream.h"
#include "Poco/Random.h"
#include "Poco/SHA1Engine.h"
#if defined(POCO_OS_FAMILY_WINDOWS)
#include "Poco/UnWindows.h"
#include <wincrypt.h>
#elif defined(POCO_OS_FAMILY_UNIX)
#include <fcntl.h>
#include <unistd.h>
#endif
#include <ctime>
namespace Poco {
RandomBuf::RandomBuf(): BufferedStreamBuf(256, std::ios::in)
{
}
RandomBuf::~RandomBuf()
{
}
int RandomBuf::readFromDevice(char* buffer, std::streamsize length)
{
int n = 0;
#if defined(POCO_OS_FAMILY_WINDOWS)
HCRYPTPROV hProvider = 0;
CryptAcquireContext(&hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
CryptGenRandom(hProvider, (DWORD) length, (BYTE*) buffer);
CryptReleaseContext(hProvider, 0);
n = static_cast<int>(length);
#else
#if defined(POCO_OS_FAMILY_UNIX)
int fd = open("/dev/urandom", O_RDONLY, 0);
if (fd >= 0)
{
n = read(fd, buffer, length);
close(fd);
}
#endif
if (n <= 0)
{
// x is here as a source of randomness, so it does not make
// much sense to protect it with a Mutex.
static UInt32 x = 0;
Random rnd1(256);
Random rnd2(64);
x += rnd1.next();
n = 0;
SHA1Engine engine;
UInt32 t = (UInt32) std::time(NULL);
engine.update(&t, sizeof(t));
void* p = this;
engine.update(&p, sizeof(p));
engine.update(buffer, length);
UInt32 junk[32];
engine.update(junk, sizeof(junk));
while (n < length)
{
for (int i = 0; i < 100; ++i)
{
UInt32 r = rnd2.next();
engine.update(&r, sizeof(r));
engine.update(&x, sizeof(x));
x += rnd1.next();
}
DigestEngine::Digest d = engine.digest();
for (DigestEngine::Digest::const_iterator it = d.begin(); it != d.end() && n < length; ++it, ++n)
{
engine.update(*it);
*buffer++ = *it++;
}
}
}
#endif
return n;
}
RandomIOS::RandomIOS()
{
poco_ios_init(&_buf);
}
RandomIOS::~RandomIOS()
{
}
RandomBuf* RandomIOS::rdbuf()
{
return &_buf;
}
RandomInputStream::RandomInputStream(): std::istream(&_buf)
{
}
RandomInputStream::~RandomInputStream()
{
}
} // namespace Poco