Rework OperateKeystream (GH #680)

This improves performance on a Core i5 6400 from 5.4 cpb to 2.9 cpb

1 files changed, 25 insertions, 26 deletions

diff --git a/hc256.cpp b/hc256.cpp
index ff75b2b2..c0bf48cc 100644
--- a/hc256.cpp
+++ b/hc256.cpp
@@ -18,43 +18,43 @@ using CryptoPP::rotrConstant;
 

 inline word32 f1(word32 x)

 {

-	return rotrConstant<7>(x) ^ rotrConstant<18>(x) ^ ((x) >> 3);

+	return rotrConstant<7>(x) ^ rotrConstant<18>(x) ^ (x >> 3);

 }

 

 inline word32 f2(word32 x)

 {

-	return rotrConstant<17>(x) ^ rotrConstant<19>(x) ^ ((x) >> 10);

+	return rotrConstant<17>(x) ^ rotrConstant<19>(x) ^ (x >> 10);

 }

 

 ANONYMOUS_NAMESPACE_END

 

 NAMESPACE_BEGIN(CryptoPP)

 

-word32 HC256Policy::H1(word32 u)

+inline word32 HC256Policy::H1(word32 u)

 {

 	word32 tem;

-	unsigned char a, b, c, d;

-	a = (unsigned char)((u));

-	b = (unsigned char)((u) >> 8);

-	c = (unsigned char)((u) >> 16);

-	d = (unsigned char)((u) >> 24);

+	byte a, b, c, d;

+	a = (byte)((u));

+	b = (byte)((u) >> 8);

+	c = (byte)((u) >> 16);

+	d = (byte)((u) >> 24);

 	tem = m_Q[a] + m_Q[256 + b] + m_Q[512 + c] + m_Q[768 + d];

 	return (tem);

 }

 

-word32 HC256Policy::H2(word32 u)

+inline word32 HC256Policy::H2(word32 u)

 {

 	word32 tem;

-	unsigned char a, b, c, d;

-	a = (unsigned char)((u));

-	b = (unsigned char)((u) >> 8);

-	c = (unsigned char)((u) >> 16);

-	d = (unsigned char)((u) >> 24);

+	byte a, b, c, d;

+	a = (byte)((u));

+	b = (byte)((u) >> 8);

+	c = (byte)((u) >> 16);

+	d = (byte)((u) >> 24);

 	tem = m_P[a] + m_P[256 + b] + m_P[512 + c] + m_P[768 + d];

 	return (tem);

 }

 

-word32 HC256Policy::Generate() /*one step of the cipher*/

+inline word32 HC256Policy::Generate() /*one step of the cipher*/

 {

 	word32 i, i3, i10, i12, i1023;

 	word32 output;

@@ -94,17 +94,16 @@ void HC256Policy::CipherSetKey(const NameValuePairs &params, const byte *userKey
 

 void HC256Policy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)

 {

-	size_t msglen = (GetBytesPerIteration() * iterationCount) >> 2;

-	for (unsigned int i = 0; i < msglen; i++, input += 4, output += 4)

-	{

-		PutWord(false, LITTLE_ENDIAN_ORDER, output, Generate());

-

-		// If AdditiveCipherTemplate does not have an acculated keystream

-		//  then it will ask OperateKeystream to XOR the plaintext with

-		//  the keystream and write it to the ciphertext buffer.

-		if ((operation & INPUT_NULL) != INPUT_NULL)

-			xorbuf(output, input, 4);

-	}

+	size_t msglen = GetBytesPerIteration() * iterationCount;

+	const byte* in = input; byte* out = output;

+	for (unsigned int i = 0; i < (msglen >> 2); i++, in += 4, out += 4)

+		PutWord(false, LITTLE_ENDIAN_ORDER, out, Generate());

+

+	// If AdditiveCipherTemplate does not have an acculated keystream

+	//  then it will ask OperateKeystream to XOR the plaintext with

+	//  the keystream and write it to the ciphertext buffer.

+	if ((operation & INPUT_NULL) != INPUT_NULL)

+		xorbuf(output, input, msglen);

 }

 

 void HC256Policy::CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)