rijndael.cpp

很好的文件加密程序,用vc++编的,适合初学者!

void CRijndael::EncryptBlock(char const* in, char* result)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
    if(DEFAULT_BLOCK_SIZE == m_blockSize)
	{
		DefEncryptBlock(in, result);
		return;
	}
	int BC = m_blockSize / 4;
	int SC = (BC == 4) ? 0 : (BC == 6 ? 1 : 2);
	int s1 = sm_shifts[SC][1][0];
	int s2 = sm_shifts[SC][2][0];
	int s3 = sm_shifts[SC][3][0];
	int i;
	int tt;
	int* pi = t;
	for(i=0; i<BC; i++)
	{
		*pi = ((unsigned char)*(in++) << 24);
		*pi |= ((unsigned char)*(in++) << 16);
		*pi |= ((unsigned char)*(in++) << 8);
		(*(pi++) |= (unsigned char)*(in++)) ^= m_Ke[0][i];
	}
	//Apply Round Transforms
	for(int r=1; r<m_iROUNDS; r++)
	{
		for(i=0; i<BC; i++)
			a[i] = (sm_T1[(t[i] >> 24) & 0xFF] ^
				sm_T2[(t[(i + s1) % BC] >> 16) & 0xFF] ^
				sm_T3[(t[(i + s2) % BC] >>  8) & 0xFF] ^
				sm_T4[ t[(i + s3) % BC] & 0xFF] ) ^ m_Ke[r][i];
		memcpy(t, a, 4*BC);
	}
	int j;
	//Last Round is Special
	for(i=0,j=0; i<BC; i++)
	{
		tt = m_Ke[m_iROUNDS][i];
		result[j++] = sm_S[(t[i] >> 24) & 0xFF] ^ (tt >> 24);
		result[j++] = sm_S[(t[(i + s1) % BC] >> 16) & 0xFF] ^ (tt >> 16);
		result[j++] = sm_S[(t[(i + s2) % BC] >>  8) & 0xFF] ^ (tt >>  8);
		result[j++] = sm_S[ t[(i + s3) % BC] & 0xFF] ^ tt;
	}
}

//Decrypt exactly one block of ciphertext.
// in         - The ciphertext.
// result     - The plaintext generated from a ciphertext using the session key.
void CRijndael::DecryptBlock(char const* in, char* result)
{
	if(false==m_bInit)
		throw runtime_error(string(sm_szErrorMsg1));
	if(DEFAULT_BLOCK_SIZE == m_blockSize)
	{
		DefDecryptBlock(in, result);
		return;
	}
	int BC = m_blockSize / 4;
	int SC = BC == 4 ? 0 : (BC == 6 ? 1 : 2);
	int s1 = sm_shifts[SC][1][1];
	int s2 = sm_shifts[SC][2][1];
	int s3 = sm_shifts[SC][3][1];
	int i;
	int tt;
	int* pi = t;
	for(i=0; i<BC; i++)
	{
		*pi = ((unsigned char)*(in++) << 24);
		*pi |= ((unsigned char)*(in++) << 16);
		*pi |= ((unsigned char)*(in++) << 8);
		(*(pi++) |= (unsigned char)*(in++)) ^= m_Kd[0][i];
	}
	//Apply Round Transforms
	for(int r=1; r<m_iROUNDS; r++)
	{
		for(i=0; i<BC; i++)
			a[i] = (sm_T5[(t[i] >> 24) & 0xFF] ^
				sm_T6[(t[(i + s1) % BC] >> 16) & 0xFF] ^
				sm_T7[(t[(i + s2) % BC] >>  8) & 0xFF] ^
				sm_T8[ t[(i + s3) % BC] & 0xFF]) ^ m_Kd[r][i];
		memcpy(t, a, 4*BC);
	}
	int j;
	//Last Round is Special
	for(i=0,j=0; i<BC; i++)
	{
		tt = m_Kd[m_iROUNDS][i];
		result[j++] = sm_Si[(t[i] >> 24) & 0xFF] ^ (tt >> 24);
		result[j++] = sm_Si[(t[(i + s1) % BC] >> 16) & 0xFF] ^ (tt >> 16);
		result[j++] = sm_Si[(t[(i + s2) % BC] >>  8) & 0xFF] ^ (tt >>  8);
		result[j++] = sm_Si[ t[(i + s3) % BC] & 0xFF] ^ tt;
	}
}

void CRijndael::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));
	int i;
	char const* pin;
	char* presult;
	if(CBC == m_iMode) //CBC mode, using the Chain
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			Xor(m_chain, pin);
			EncryptBlock(m_chain, presult);
			memcpy(m_chain, presult, m_blockSize);
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
	else if(CFB == m_iMode) //CFB mode, using the Chain
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			EncryptBlock(m_chain, presult);
			Xor(presult, pin);
			memcpy(m_chain, presult, m_blockSize);
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
	else //ECB mode, not using the Chain
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			EncryptBlock(pin, presult);
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
}

void CRijndael::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));
	int i;
	char const* pin;
	char* presult;
	if(CBC == m_iMode) //CBC mode, using the Chain
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			DecryptBlock(pin, presult);
			Xor(presult, m_chain);
			memcpy(m_chain, pin, m_blockSize);				
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
	else if(CFB == m_iMode) //CFB mode, using the Chain, not using Decrypt()
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			EncryptBlock(m_chain, presult);
			//memcpy(presult, pin, m_blockSize);
			Xor(presult, pin);
			memcpy(m_chain, pin, m_blockSize);
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
	else //ECB mode, not using the Chain
	{
		for(i=0,pin=in,presult=result; i<n/m_blockSize; i++)
		{
			DecryptBlock(pin, presult);
			pin += m_blockSize;
			presult += m_blockSize;
		}
	}
}

void CRijndael::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};
	char szBuffIn[DATA_LEN+1] = {0};
	char szBuffOut[DATA_LEN+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 CRijndael::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};
	char szBuffIn[DATA_LEN+1] = {0};
	char szBuffOut[DATA_LEN+1] = {0};
	CDoubleBuffering oDoubleBuffering(in, szLargeBuff, BUFF_LEN, DATA_LEN);
	int iRead;
	while((iRead=oDoubleBuffering.GetData(szBuffIn)) > 0)
	{
		//Decrypting
		Decrypt(szBuffIn, szBuffOut, iRead);
		out.write(szBuffOut, iRead);
	}
	in.close();
	out.close();
}