xor256block.cpp

一些加密算法的介绍,可对文件或字符串加密

	unsigned char const* pucXOR_1;
	unsigned char const* puc256_1;
	pucBlock += m_iBlockSize1;
	for(int i=0; i<m_blockSize; i++,pucBlock--)
	{
		pucXOR += m_iIRounds;
		puc256 += m_iIRounds;
		pucXOR_1 = pucXOR - 1;
		puc256_1 = puc256 - 1;
		//The Last m_iIRounds-1 Internal Rounds
		for(int j=m_iIRounds1; j>0; j--,pucXOR_1--,puc256_1--)
		{
			if(*puc256_1 <= *pucBlock)
				*pucBlock -= *puc256_1;
			else
				(*pucBlock += ~(*puc256_1))++;
			*pucBlock ^= *pucXOR_1;
		}
		//The First Internal Round
		if(*puc256_1 <= *pucBlock)
			*pucBlock -= *puc256_1;
		else
			(*pucBlock += ~(*puc256_1))++;
		*pucBlock ^= ucPrev ^ *pucXOR_1;
		ucPrev ^= *pucBlock;
	}
}

void CXOR256Block::EncryptBlock(unsigned char* pucBlock)
{
	unsigned char const* pucXOR = m_pucXOR;
	unsigned char const* puc256 = m_puc256;
	bool bDir = true;
	for(int i=0; i<m_iORounds1; i++,pucXOR+=m_iProd,puc256+=m_iProd)
	{
		if(true == bDir)
			EncryptDirect(pucBlock, pucXOR, puc256);
		else
			EncryptReverse(pucBlock, pucXOR, puc256);
		bDir = !bDir;
	}
	if(true == bDir)
		EncryptDirect1(pucBlock, pucXOR, puc256);
	else
		EncryptReverse1(pucBlock, pucXOR, puc256);
}

void CXOR256Block::DecryptBlock(unsigned char* pucBlock)
{
	unsigned char const* pucXOR = m_pucXOR + m_iDelta;
	unsigned char const* puc256 = m_puc256 + m_iDelta;
	bool bDir;	
	if(1 == m_iORounds%2)
	{
		DecryptDirect1(pucBlock, pucXOR, puc256);
		bDir = false;
	}
	else
	{
		DecryptReverse1(pucBlock, pucXOR, puc256);
		bDir = true;
	}
	pucXOR-=m_iProd;
	puc256-=m_iProd;
	for(int i=0; i<m_iORounds1; i++,pucXOR-=m_iProd,puc256-=m_iProd)
	{
		if(true == bDir)
			DecryptDirect(pucBlock, pucXOR, puc256);
		else
			DecryptReverse(pucBlock, pucXOR, puc256);
		bDir = !bDir;
	}
}

void CXOR256Block::Encrypt(char const* in, char* result, size_t n)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
	//n should be > 0 and multiple of m_blockSize
	if(n<1 || n%m_blockSize!=0)
		throw runtime_error(string(sm_szErrorMsg6));
	unsigned int ui;
	unsigned char const* pucCurrentIn;
	unsigned char* pucCurrentOut;
	if(m_iMode == CBC) //CBC mode, using the Chain
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			Xor(reinterpret_cast<char*>(pucCurrentOut), m_apchain.get());
			EncryptBlock(pucCurrentOut);
			memcpy(m_apchain.get(), pucCurrentOut, m_blockSize);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
	else if(m_iMode == CFB) //CFB mode, using the Chain
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			EncryptBlock(reinterpret_cast<unsigned char*>(m_apchain.get()));
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			Xor(reinterpret_cast<char*>(pucCurrentOut), m_apchain.get());
			memcpy(m_apchain.get(), pucCurrentOut, m_blockSize);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
	else //ECB mode, not using the Chain
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			EncryptBlock(pucCurrentOut);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
}

void CXOR256Block::Decrypt(char const* in, char* result, size_t n)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
	//n should be > 0 and multiple of m_blockSize
	if(n<1 || n%m_blockSize!=0)
		throw runtime_error(string(sm_szErrorMsg6));
	unsigned int ui;
	unsigned char const* pucCurrentIn;
	unsigned char* pucCurrentOut;
	if(m_iMode == CBC) //CBC mode, using the Chain
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			memcpy(m_apTemp.get(), pucCurrentOut, m_blockSize);
			DecryptBlock(pucCurrentOut);
			Xor(reinterpret_cast<char*>(pucCurrentOut), m_apchain.get());
			memcpy(m_apchain.get(), m_apTemp.get(), m_blockSize);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
	else if(m_iMode == CFB) //CFB mode, using the Chain, not using Decrypt()
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			EncryptBlock(reinterpret_cast<unsigned char*>(m_apchain.get()));
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			memcpy(m_apTemp.get(), pucCurrentOut, m_blockSize);
			Xor(reinterpret_cast<char*>(pucCurrentOut), m_apchain.get());
			memcpy(m_apchain.get(), m_apTemp.get(), m_blockSize);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
	else //ECB mode, not using the Chain
	{
		for(ui=0,pucCurrentIn=reinterpret_cast<unsigned char const*>(in),
			pucCurrentOut=reinterpret_cast<unsigned char*>(result); ui<n/m_blockSize; ui++)
		{
			memcpy(pucCurrentOut, pucCurrentIn, m_blockSize);
			DecryptBlock(pucCurrentOut);
			pucCurrentIn += m_blockSize;
			pucCurrentOut += m_blockSize;
		}
	}
}

void CXOR256Block::EncryptFile(string const& rostrFileIn, string const& rostrFileOut)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
	//Check if the same file for input and output
	if(rostrFileIn == rostrFileOut)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg8 << rostrFileIn << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Open Input File
	ifstream in(rostrFileIn.c_str(), ios::binary);
	if(!in)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg7 << rostrFileIn << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Open Output File
	ofstream out(rostrFileOut.c_str(), ios::binary);
	if(!out)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg7 << rostrFileOut << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Computing the signature
	char acSig[33] = {0};
	Signature(acSig);
	//Writing the Signature
	out.write(acSig, 32);
	//Resetting the chain
	ResetChain();
	//Reading from file
	char szLargeBuff[BUFF_LEN+1] = {0};
	int DATA_LEN = (BUFF_LEN/m_blockSize/2)*m_blockSize;
	char szBuffIn[BUFF_LEN/2+1] = {0};
	char szBuffOut[BUFF_LEN/2+1] = {0};
	CDoubleBuffering oDoubleBuffering(in, szLargeBuff, BUFF_LEN, DATA_LEN);
	int iRead;
	while((iRead=oDoubleBuffering.GetData(szBuffIn)) > 0)
	{
		if(iRead < DATA_LEN)
			iRead = Pad(szBuffIn, iRead);
		//Encrypting
		Encrypt(szBuffIn, szBuffOut, iRead);
		out.write(szBuffOut, iRead);
	}
	in.close();
	out.close();
}

void CXOR256Block::DecryptFile(string const& rostrFileIn, string const& rostrFileOut)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
	//Check if the same file for input and output
	if(rostrFileIn == rostrFileOut)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg8 << rostrFileIn << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Open Input File
	ifstream in(rostrFileIn.c_str(), ios::binary);
	if(!in)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg7 << rostrFileIn << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Open Output File
	ofstream out(rostrFileOut.c_str(), ios::binary);
	if(!out)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg7 << rostrFileOut << "!" << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Computing the signature
	char acSig[33] = {0};
	Signature(acSig);
	char acSig1[33] = {0};
	//Reading the Signature
	in.read(acSig1, 32);
	//Compare the signatures
	if(memcmp(acSig1, acSig, 32) != 0)
	{
		ostrstream ostr;
		ostr << sm_szErrorMsg9 << rostrFileIn << sm_szErrorMsg10 << ends;
		string ostrMsg = ostr.str();
		ostr.freeze(false);
		throw runtime_error(ostrMsg);
	}
	//Resetting the chain
	ResetChain();
	//Reading from file
	char szLargeBuff[BUFF_LEN+1] = {0};
	int DATA_LEN = (BUFF_LEN/m_blockSize/2)*m_blockSize;
	char szBuffIn[BUFF_LEN/2+1] = {0};
	char szBuffOut[BUFF_LEN/2+1] = {0};
	CDoubleBuffering oDoubleBuffering(in, szLargeBuff, BUFF_LEN, DATA_LEN);
	int iRead;
	while((iRead=oDoubleBuffering.GetData(szBuffIn)) > 0)
	{
		//Encrypting
		Decrypt(szBuffIn, szBuffOut, iRead);
		out.write(szBuffOut, iRead);
	}
	in.close();
	out.close();
}