randomstream.cpp

This software aims to create an applet and panel tools to manage a wireless interface card, such as

//
// RandomStream.cpp
//
// $Id: //poco/Main/Foundation/src/RandomStream.cpp#5 $
//
// Copyright (c) 2004, Guenter Obiltschnig/Applied Informatics.
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 
// 3. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//


#include "Foundation/RandomStream.h"
#include "Foundation/Random.h"
#include "Foundation/SHA1Engine.h"
#if defined(POCO_OS_FAMILY_WINDOWS)
#include <windows.h>
#include <wincrypt.h>
#elif defined(POCO_OS_FAMILY_UNIX)
#include <fcntl.h>
#include <unistd.h>
#endif
#include <time.h>


Foundation_BEGIN


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, length, (BYTE*) buffer);
	CryptReleaseContext(hProvider, 0);
	n = 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) 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()
{
	init(&_buf);
}


RandomIOS::~RandomIOS()
{
}


RandomBuf* RandomIOS::rdbuf()
{
	return &_buf;
}


RandomInputStream::RandomInputStream(): std::istream(&_buf)
{
}


RandomInputStream::~RandomInputStream()
{
}


Foundation_END