filters.cpp

lots Elliptic curve cryptography codes. Use Visual c++ to compile

					newLength -= m_blockSize;
				}

				if (newLength >= m_blockSize + m_lastSize && m_queue.CurrentSize() > 0)
				{
					assert(m_queue.CurrentSize() < m_blockSize);
					size_t len = m_blockSize - m_queue.CurrentSize();
					m_queue.Put(inString, len);
					inString += len;
					NextPutModifiable(m_queue.GetBlock(), m_blockSize);
					newLength -= m_blockSize;
				}

				if (newLength >= m_blockSize + m_lastSize)
				{
					size_t len = RoundDownToMultipleOf(newLength - m_lastSize, m_blockSize);
					NextPutMaybeModifiable(inString, len, modifiable);
					inString += len;
					newLength -= len;
				}
			}
		}

		m_queue.Put(inString, newLength - m_queue.CurrentSize());
	}

	if (messageEnd)
	{
		if (!m_firstInputDone && m_firstSize==0)
			FirstPut(NULL);

		SecByteBlock temp(m_queue.CurrentSize());
		m_queue.GetAll(temp);
		LastPut(temp, temp.size());

		m_firstInputDone = false;
		m_queue.ResetQueue(1, m_firstSize);

		Output(1, NULL, 0, messageEnd, blocking);
	}
	return 0;
}

void FilterWithBufferedInput::ForceNextPut()
{
	if (!m_firstInputDone)
		return;
	
	if (m_blockSize > 1)
	{
		while (m_queue.CurrentSize() >= m_blockSize)
			NextPutModifiable(m_queue.GetBlock(), m_blockSize);
	}
	else
	{
		size_t len;
		while ((len = m_queue.CurrentSize()) > 0)
			NextPutModifiable(m_queue.GetContigousBlocks(len), len);
	}
}

void FilterWithBufferedInput::NextPutMultiple(const byte *inString, size_t length)
{
	assert(m_blockSize > 1);	// m_blockSize = 1 should always override this function
	while (length > 0)
	{
		assert(length >= m_blockSize);
		NextPutSingle(inString);
		inString += m_blockSize;
		length -= m_blockSize;
	}
}

// *************************************************************

void Redirector::Initialize(const NameValuePairs &parameters, int propagation)
{
	m_target = parameters.GetValueWithDefault("RedirectionTargetPointer", (BufferedTransformation*)NULL);
	m_behavior = parameters.GetIntValueWithDefault("RedirectionBehavior", PASS_EVERYTHING);

	if (m_target && GetPassSignals())
		m_target->Initialize(parameters, propagation);
}

// *************************************************************

ProxyFilter::ProxyFilter(BufferedTransformation *filter, size_t firstSize, size_t lastSize, BufferedTransformation *attachment)
	: FilterWithBufferedInput(firstSize, 1, lastSize, attachment), m_filter(filter)
{
	if (m_filter.get())
		m_filter->Attach(new OutputProxy(*this, false));
}

bool ProxyFilter::IsolatedFlush(bool hardFlush, bool blocking)
{
	return m_filter.get() ? m_filter->Flush(hardFlush, -1, blocking) : false;
}

void ProxyFilter::SetFilter(Filter *filter)
{
	m_filter.reset(filter);
	if (filter)
	{
		OutputProxy *proxy;
		std::auto_ptr<OutputProxy> temp(proxy = new OutputProxy(*this, false));
		m_filter->TransferAllTo(*proxy);
		m_filter->Attach(temp.release());
	}
}

void ProxyFilter::NextPutMultiple(const byte *s, size_t len)
{
	if (m_filter.get())
		m_filter->Put(s, len);
}

void ProxyFilter::NextPutModifiable(byte *s, size_t len)
{
	if (m_filter.get())
		m_filter->PutModifiable(s, len);
}

// *************************************************************

void RandomNumberSink::IsolatedInitialize(const NameValuePairs &parameters)
{
	parameters.GetRequiredParameter("RandomNumberSink", "RandomNumberGeneratorPointer", m_rng);
}

size_t RandomNumberSink::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
	m_rng->IncorporateEntropy(begin, length);
	return 0;
}

size_t ArraySink::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
	if (m_buf+m_total != begin)
		memcpy(m_buf+m_total, begin, STDMIN(length, SaturatingSubtract(m_size, m_total)));
	m_total += length;
	return 0;
}

byte * ArraySink::CreatePutSpace(size_t &size)
{
	size = SaturatingSubtract(m_size, m_total);
	return m_buf + m_total;
}

void ArraySink::IsolatedInitialize(const NameValuePairs &parameters)
{
	ByteArrayParameter array;
	if (!parameters.GetValue(Name::OutputBuffer(), array))
		throw InvalidArgument("ArraySink: missing OutputBuffer argument");
	m_buf = array.begin();
	m_size = array.size();
	m_total = 0;
}

size_t ArrayXorSink::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
	xorbuf(m_buf+m_total, begin, STDMIN(length, SaturatingSubtract(m_size, m_total)));
	m_total += length;
	return 0;
}

// *************************************************************

StreamTransformationFilter::StreamTransformationFilter(StreamTransformation &c, BufferedTransformation *attachment, BlockPaddingScheme padding, bool allowAuthenticatedSymmetricCipher)
   : FilterWithBufferedInput(attachment)
	, m_cipher(c)
{
	assert(c.MinLastBlockSize() == 0 || c.MinLastBlockSize() > c.MandatoryBlockSize());

	if (!allowAuthenticatedSymmetricCipher && dynamic_cast<AuthenticatedSymmetricCipher *>(&c) != 0)
		throw InvalidArgument("StreamTransformationFilter: please use AuthenticatedEncryptionFilter and AuthenticatedDecryptionFilter for AuthenticatedSymmetricCipher");

	IsolatedInitialize(MakeParameters(Name::BlockPaddingScheme(), padding));
}

size_t StreamTransformationFilter::LastBlockSize(StreamTransformation &c, BlockPaddingScheme padding)
{
	if (c.MinLastBlockSize() > 0)
		return c.MinLastBlockSize();
	else if (c.MandatoryBlockSize() > 1 && !c.IsForwardTransformation() && padding != NO_PADDING && padding != ZEROS_PADDING)
		return c.MandatoryBlockSize();
	else
		return 0;
}

void StreamTransformationFilter::InitializeDerivedAndReturnNewSizes(const NameValuePairs &parameters, size_t &firstSize, size_t &blockSize, size_t &lastSize)
{
	BlockPaddingScheme padding = parameters.GetValueWithDefault(Name::BlockPaddingScheme(), DEFAULT_PADDING);
	bool isBlockCipher = (m_cipher.MandatoryBlockSize() > 1 && m_cipher.MinLastBlockSize() == 0);

	if (padding == DEFAULT_PADDING)
		m_padding = isBlockCipher ? PKCS_PADDING : NO_PADDING;
	else
		m_padding = padding;

	if (!isBlockCipher && (m_padding == PKCS_PADDING || m_padding == ONE_AND_ZEROS_PADDING))
		throw InvalidArgument("StreamTransformationFilter: PKCS_PADDING and ONE_AND_ZEROS_PADDING cannot be used with " + m_cipher.AlgorithmName());

	firstSize = 0;
	blockSize = m_cipher.MandatoryBlockSize();
	lastSize = LastBlockSize(m_cipher, m_padding);
}

void StreamTransformationFilter::FirstPut(const byte *inString)
{
	m_optimalBufferSize = m_cipher.OptimalBlockSize();
	m_optimalBufferSize = (unsigned int)STDMAX(m_optimalBufferSize, RoundDownToMultipleOf(4096U, m_optimalBufferSize));
}

void StreamTransformationFilter::NextPutMultiple(const byte *inString, size_t length)
{
	if (!length)
		return;

	size_t s = m_cipher.MandatoryBlockSize();

	do
	{
		size_t len = m_optimalBufferSize;
		byte *space = HelpCreatePutSpace(*AttachedTransformation(), DEFAULT_CHANNEL, s, length, len);
		if (len < length)
		{
			if (len == m_optimalBufferSize)
				len -= m_cipher.GetOptimalBlockSizeUsed();
			len = RoundDownToMultipleOf(len, s);
		}
		else
			len = length;
		m_cipher.ProcessString(space, inString, len);
		AttachedTransformation()->PutModifiable(space, len);
		inString += len;
		length -= len;
	}
	while (length > 0);
}

void StreamTransformationFilter::NextPutModifiable(byte *inString, size_t length)
{
	m_cipher.ProcessString(inString, length);
	AttachedTransformation()->PutModifiable(inString, length);
}

void StreamTransformationFilter::LastPut(const byte *inString, size_t length)
{
	byte *space = NULL;
	
	switch (m_padding)
	{
	case NO_PADDING:
	case ZEROS_PADDING:
		if (length > 0)
		{
			size_t minLastBlockSize = m_cipher.MinLastBlockSize();
			bool isForwardTransformation = m_cipher.IsForwardTransformation();

			if (isForwardTransformation && m_padding == ZEROS_PADDING && (minLastBlockSize == 0 || length < minLastBlockSize))
			{
				// do padding
				size_t blockSize = STDMAX(minLastBlockSize, (size_t)m_cipher.MandatoryBlockSize());
				space = HelpCreatePutSpace(*AttachedTransformation(), DEFAULT_CHANNEL, blockSize);
				memcpy(space, inString, length);
				memset(space + length, 0, blockSize - length);
				m_cipher.ProcessLastBlock(space, space, blockSize);
				AttachedTransformation()->Put(space, blockSize);
			}
			else
			{
				if (minLastBlockSize == 0)
				{
					if (isForwardTransformation)
						throw InvalidDataFormat("StreamTransformationFilter: plaintext length is not a multiple of block size and NO_PADDING is specified");
					else
						throw InvalidCiphertext("StreamTransformationFilter: ciphertext length is not a multiple of block size");
				}

				space = HelpCreatePutSpace(*AttachedTransformation(), DEFAULT_CHANNEL, length, m_optimalBufferSize);
				m_cipher.ProcessLastBlock(space, inString, length);
				AttachedTransformation()->Put(space, length);
			}
		}
		break;

	case PKCS_PADDING:
	case ONE_AND_ZEROS_PADDING:
		unsigned int s;
		s = m_cipher.MandatoryBlockSize();
		assert(s > 1);
		space = HelpCreatePutSpace(*AttachedTransformation(), DEFAULT_CHANNEL, s, m_optimalBufferSize);
		if (m_cipher.IsForwardTransformation())
		{
			assert(length < s);
			memcpy(space, inString, length);
			if (m_padding == PKCS_PADDING)
			{
				assert(s < 256);
				byte pad = byte(s-length);
				memset(space+length, pad, s-length);
			}
			else
			{
				space[length] = 0x80;
				memset(space+length+1, 0, s-length-1);
			}
			m_cipher.ProcessData(space, space, s);
			AttachedTransformation()->Put(space, s);
		}
		else
		{
			if (length != s)
				throw InvalidCiphertext("StreamTransformationFilter: ciphertext length is not a multiple of block size");
			m_cipher.ProcessData(space, inString, s);
			if (m_padding == PKCS_PADDING)
			{
				byte pad = space[s-1];
				if (pad < 1 || pad > s || std::find_if(space+s-pad, space+s, std::bind2nd(std::not_equal_to<byte>(), pad)) != space+s)
					throw InvalidCiphertext("StreamTransformationFilter: invalid PKCS #7 block padding found");
				length = s-pad;
			}
			else
			{
				while (length > 1 && space[length-1] == 0)
					--length;
				if (space[--length] != 0x80)
					throw InvalidCiphertext("StreamTransformationFilter: invalid ones-and-zeros padding found");
			}
			AttachedTransformation()->Put(space, length);
		}
		break;

	default:
		assert(false);
	}
}

// *************************************************************

HashFilter::HashFilter(HashTransformation &hm, BufferedTransformation *attachment, bool putMessage, int truncatedDigestSize, const std::string &messagePutChannel, const std::string &hashPutChannel)
	: m_hashModule(hm), m_putMessage(putMessage), m_messagePutChannel(messagePutChannel), m_hashPutChannel(hashPutChannel)
{
	m_digestSize = truncatedDigestSize < 0 ? m_hashModule.DigestSize() : truncatedDigestSize;
	Detach(attachment);
}

void HashFilter::IsolatedInitialize(const NameValuePairs &parameters)
{
	m_putMessage = parameters.GetValueWithDefault(Name::PutMessage(), false);
	int s = parameters.GetIntValueWithDefault(Name::TruncatedDigestSize(), -1);
	m_digestSize = s < 0 ? m_hashModule.DigestSize() : s;
}

size_t HashFilter::Put2(const byte *inString, size_t length, int messageEnd, bool blocking)
{
	FILTER_BEGIN;
	if (m_putMessage)
		FILTER_OUTPUT3(1, 0, inString, length, 0, m_messagePutChannel);
	m_hashModule.Update(inString, length);
	if (messageEnd)
	{
		{
			size_t size;
			m_space = HelpCreatePutSpace(*AttachedTransformation(), m_hashPutChannel, m_digestSize, m_digestSize, size = m_digestSize);
			m_hashModule.TruncatedFinal(m_space, m_digestSize);
		}
		FILTER_OUTPUT3(2, 0, m_space, m_digestSize, messageEnd, m_hashPutChannel);
	}
	FILTER_END_NO_MESSAGE_END;
}

// *************************************************************