Align input buffer in HashMultipleBlocks

IteratedHashBase::Update aligns the buffer, but IteratedHashBase::HashBlock does not. It was causing a fair number of asserts to fire when the code was instrumented with alignment checks. Linux benchmarks shows the code does not run materially slower on i686 or x86_64.

1 files changed, 26 insertions, 7 deletions

diff --git a/iterhash.cpp b/iterhash.cpp
index 91e00af8..e9974ced 100644
--- a/iterhash.cpp
+++ b/iterhash.cpp
@@ -27,13 +27,14 @@ template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte
 

 	T* dataBuf = this->DataBuf();

 	byte* data = (byte *)dataBuf;

-	CRYPTOPP_ASSERT(dataBuf && data);

 

 	if (num != 0)	// process left over data

 	{

 		if (num+length >= blockSize)

 		{

-			if (data && input) {memcpy(data+num, input, blockSize-num);}

+			if (input)

+				{memcpy(data+num, input, blockSize-num);}

+

 			HashBlock(dataBuf);

 			input += (blockSize-num);

 			length -= (blockSize-num);

@@ -42,7 +43,8 @@ template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte
 		}

 		else

 		{

-			if (data && input && length) {memcpy(data+num, input, length);}

+			if (input && length)

+				{memcpy(data+num, input, length);}

 			return;

 		}

 	}

@@ -63,16 +65,20 @@ template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte
 			length = leftOver;

 		}

 		else

+		{

 			do

 			{   // copy input first if it's not aligned correctly

-				if (data && input) memcpy(data, input, blockSize);

+				if (input)

+					{ memcpy(data, input, blockSize); }

+

 				HashBlock(dataBuf);

 				input+=blockSize;

 				length-=blockSize;

 			} while (length >= blockSize);

+		}

 	}

 

-	if (data && input && data != input)

+	if (input && data != input)

 		memcpy(data, input, length);

 }

 

@@ -89,10 +95,22 @@ template <class T, class BASE> size_t IteratedHashBase<T, BASE>::HashMultipleBlo
 	unsigned int blockSize = this->BlockSize();

 	bool noReverse = NativeByteOrderIs(this->GetByteOrder());

 	T* dataBuf = this->DataBuf();

+

+	// IteratedHashBase Update calls this with an aligned input,

+	// but HashBlock may call it with an unaligned buffer.

+

 	do

 	{

 		if (noReverse)

-			this->HashEndianCorrectedBlock(input);

+		{

+			if (IsAligned<word64>(input))

+				this->HashEndianCorrectedBlock(input);

+			else

+			{

+				std::memcpy(dataBuf, input, this->BlockSize());

+				this->HashEndianCorrectedBlock(dataBuf);

+			}

+		}

 		else

 		{

 			ByteReverse(dataBuf, input, this->BlockSize());

@@ -112,6 +130,7 @@ template <class T, class BASE> void IteratedHashBase<T, BASE>::PadLastBlock(unsi
 	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);

@@ -150,7 +169,7 @@ template <class T, class BASE> void IteratedHashBase<T, BASE>::TruncatedFinal(by
 	else

 	{

 		ConditionalByteReverse<HashWordType>(order, stateBuf, stateBuf, this->DigestSize());

-		memcpy(digest, stateBuf, size);

+		std::memcpy(digest, stateBuf, size);

 	}

 

 	this->Restart();		// reinit for next use