Add ChaCha NEON implementation

1 files changed, 33 insertions, 1 deletions

diff --git a/chacha.cpp b/chacha.cpp
index 23fd3be8..aa2e9268 100644
--- a/chacha.cpp
+++ b/chacha.cpp
@@ -11,6 +11,10 @@
 

 NAMESPACE_BEGIN(CryptoPP)

 

+#if (CRYPTOPP_ARM_NEON_AVAILABLE)

+extern void ChaCha_OperateKeystream_NEON(const word32 *state, const byte* input, byte *output, unsigned int rounds, bool xorInput);

+#endif

+

 #if (CRYPTOPP_SSE2_INTRIN_AVAILABLE || CRYPTOPP_SSE2_ASM_AVAILABLE)

 extern void ChaCha_OperateKeystream_SSE2(const word32 *state, const byte* input, byte *output, unsigned int rounds, bool xorInput);

 #endif

@@ -34,6 +38,10 @@ std::string ChaCha_Policy::AlgorithmProvider() const
 	if (HasSSE2())

 		return "SSE2";

 #endif

+#if (CRYPTOPP_ARM_NEON_AVAILABLE)

+	if (HasNEON())

+		return "NEON";

+#endif

 	return "C++";

 }

 

@@ -92,6 +100,11 @@ unsigned int ChaCha_Policy::GetOptimalBlockSize() const
 		return 4*BYTES_PER_ITERATION;

 	else

 #endif

+#if (CRYPTOPP_ARM_NEON_AVAILABLE)

+	if (HasNEON())

+		return 4*BYTES_PER_ITERATION;

+	else

+#endif

 		return BYTES_PER_ITERATION;

 }

 

@@ -113,7 +126,26 @@ void ChaCha_Policy::OperateKeystream(KeystreamOperation operation,
 			if (m_state[12] < 4)

 				m_state[13]++;

 

-			input += !!xorInput*4*BYTES_PER_ITERATION;

+			input += (!!xorInput)*4*BYTES_PER_ITERATION;

+			output += 4*BYTES_PER_ITERATION;

+			iterationCount -= 4;

+		}

+	}

+#endif

+

+#if (CRYPTOPP_ARM_NEON_AVAILABLE)

+	if (HasNEON())

+	{

+		while (iterationCount >= 4)

+		{

+			bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;

+			ChaCha_OperateKeystream_NEON(m_state, input, output, m_rounds, xorInput);

+

+			m_state[12] += 4;

+			if (m_state[12] < 4)

+				m_state[13]++;

+

+			input += (!!xorInput)*4*BYTES_PER_ITERATION;

 			output += 4*BYTES_PER_ITERATION;

 			iterationCount -= 4;

 		}