1 files changed, 160 insertions, 0 deletions

diff --git a/CryptoPP/iterhash.cpp b/CryptoPP/iterhash.cpp
new file mode 100644
index 000000000..1e31e9fb3
--- /dev/null
+++ b/CryptoPP/iterhash.cpp
@@ -0,0 +1,160 @@
+// iterhash.cpp - written and placed in the public domain by Wei Dai
+
+#ifndef __GNUC__
+#define CRYPTOPP_MANUALLY_INSTANTIATE_TEMPLATES
+#endif
+
+#include "iterhash.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte *input, size_t len)
+{
+	HashWordType oldCountLo = m_countLo, oldCountHi = m_countHi;
+	if ((m_countLo = oldCountLo + HashWordType(len)) < oldCountLo)
+		m_countHi++;             // carry from low to high
+	m_countHi += (HashWordType)SafeRightShift<8*sizeof(HashWordType)>(len);
+	if (m_countHi < oldCountHi || SafeRightShift<2*8*sizeof(HashWordType)>(len) != 0)
+		throw HashInputTooLong(this->AlgorithmName());
+
+	unsigned int blockSize = this->BlockSize();
+	unsigned int num = ModPowerOf2(oldCountLo, blockSize);
+	T* dataBuf = this->DataBuf();
+	byte* data = (byte *)dataBuf;
+
+	if (num != 0)	// process left over data
+	{
+		if (num+len >= blockSize)
+		{
+			memcpy(data+num, input, blockSize-num);
+			HashBlock(dataBuf);
+			input += (blockSize-num);
+			len -= (blockSize-num);
+			num = 0;
+			// drop through and do the rest
+		}
+		else
+		{
+			memcpy(data+num, input, len);
+			return;
+		}
+	}
+
+	// now process the input data in blocks of blockSize bytes and save the leftovers to m_data
+	if (len >= blockSize)
+	{
+		if (input == data)
+		{
+			assert(len == blockSize);
+			HashBlock(dataBuf);
+			return;
+		}
+		else if (IsAligned<T>(input))
+		{
+			size_t leftOver = HashMultipleBlocks((T *)input, len);
+			input += (len - leftOver);
+			len = leftOver;
+		}
+		else
+			do
+			{   // copy input first if it's not aligned correctly
+				memcpy(data, input, blockSize);
+				HashBlock(dataBuf);
+				input+=blockSize;
+				len-=blockSize;
+			} while (len >= blockSize);
+	}
+
+	if (len && data != input)
+		memcpy(data, input, len);
+}
+
+template <class T, class BASE> byte * IteratedHashBase<T, BASE>::CreateUpdateSpace(size_t &size)
+{
+	unsigned int blockSize = this->BlockSize();
+	unsigned int num = ModPowerOf2(m_countLo, blockSize);
+	size = blockSize - num;
+	return (byte *)DataBuf() + num;
+}
+
+template <class T, class BASE> size_t IteratedHashBase<T, BASE>::HashMultipleBlocks(const T *input, size_t length)
+{
+	unsigned int blockSize = this->BlockSize();
+	bool noReverse = NativeByteOrderIs(this->GetByteOrder());
+	T* dataBuf = this->DataBuf();
+	do
+	{
+		if (noReverse)
+			this->HashEndianCorrectedBlock(input);
+		else
+		{
+			ByteReverse(dataBuf, input, this->BlockSize());
+			this->HashEndianCorrectedBlock(dataBuf);
+		}
+
+		input += blockSize/sizeof(T);
+		length -= blockSize;
+	}
+	while (length >= blockSize);
+	return length;
+}
+
+template <class T, class BASE> void IteratedHashBase<T, BASE>::PadLastBlock(unsigned int lastBlockSize, byte padFirst)
+{
+	unsigned int blockSize = this->BlockSize();
+	unsigned int num = ModPowerOf2(m_countLo, blockSize);
+	T* dataBuf = this->DataBuf();
+	byte* data = (byte *)dataBuf;
+	data[num++] = padFirst;
+	if (num <= lastBlockSize)
+		memset(data+num, 0, lastBlockSize-num);
+	else
+	{
+		memset(data+num, 0, blockSize-num);
+		HashBlock(dataBuf);
+		memset(data, 0, lastBlockSize);
+	}
+}
+
+template <class T, class BASE> void IteratedHashBase<T, BASE>::Restart()
+{
+	m_countLo = m_countHi = 0;
+	Init();
+}
+
+template <class T, class BASE> void IteratedHashBase<T, BASE>::TruncatedFinal(byte *digest, size_t size)
+{
+	this->ThrowIfInvalidTruncatedSize(size);
+
+	T* dataBuf = this->DataBuf();
+	T* stateBuf = this->StateBuf();
+	unsigned int blockSize = this->BlockSize();
+	ByteOrder order = this->GetByteOrder();
+
+	PadLastBlock(blockSize - 2*sizeof(HashWordType));
+	dataBuf[blockSize/sizeof(T)-2+order] = ConditionalByteReverse(order, this->GetBitCountLo());
+	dataBuf[blockSize/sizeof(T)-1-order] = ConditionalByteReverse(order, this->GetBitCountHi());
+
+	HashBlock(dataBuf);
+
+	if (IsAligned<HashWordType>(digest) && size%sizeof(HashWordType)==0)
+		ConditionalByteReverse<HashWordType>(order, (HashWordType *)digest, stateBuf, size);
+	else
+	{
+		ConditionalByteReverse<HashWordType>(order, stateBuf, stateBuf, this->DigestSize());
+		memcpy(digest, stateBuf, size);
+	}
+
+	this->Restart();		// reinit for next use
+}
+
+#ifdef __GNUC__
+	template class IteratedHashBase<word64, HashTransformation>;
+	template class IteratedHashBase<word64, MessageAuthenticationCode>;
+
+	template class IteratedHashBase<word32, HashTransformation>;
+	template class IteratedHashBase<word32, MessageAuthenticationCode>;
+#endif
+
+NAMESPACE_END