From b21162cf8e06f40baa1f58be6a8c17435cebc34d Mon Sep 17 00:00:00 2001
From: weidai <weidai@57ff6487-cd31-0410-9ec3-f628ee90f5f0>
Date: Fri, 4 Oct 2002 17:31:41 +0000
Subject: Initial revision

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/trunk/c5@2 57ff6487-cd31-0410-9ec3-f628ee90f5f0
---
 3way.cpp | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 3way.cpp

(limited to '3way.cpp')

diff --git a/3way.cpp b/3way.cpp
new file mode 100644
index 0000000..0b7d4f2
--- /dev/null
+++ b/3way.cpp
@@ -0,0 +1,140 @@
+// 3way.cpp - modifed by Wei Dai from Joan Daemen's 3way.c
+// The original code and all modifications are in the public domain.
+
+#include "pch.h"
+#include "3way.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void ThreeWay_TestInstantiations()
+{
+	ThreeWay::Encryption x1;
+	ThreeWay::Decryption x2;
+}
+
+static const word32 START_E = 0x0b0b; // round constant of first encryption round
+static const word32 START_D = 0xb1b1; // round constant of first decryption round
+static const word32 RC_MODULUS = 0x11011;
+
+static inline word32 reverseBits(word32 a)
+{
+	a = ((a & 0xAAAAAAAA) >> 1) | ((a & 0x55555555) << 1);
+	a = ((a & 0xCCCCCCCC) >> 2) | ((a & 0x33333333) << 2);
+	return ((a & 0xF0F0F0F0) >> 4) | ((a & 0x0F0F0F0F) << 4);
+}
+
+#define mu(a0, a1, a2)				\
+{									\
+	a1 = reverseBits(a1);			\
+	word32 t = reverseBits(a0);		\
+	a0 = reverseBits(a2);			\
+	a2 = t;							\
+}
+
+#define pi_gamma_pi(a0, a1, a2)		\
+{									\
+	word32 b0, b2;					\
+	b2 = rotlFixed(a2, 1U);				\
+	b0 = rotlFixed(a0, 22U);				\
+	a0 = rotlFixed(b0 ^ (a1|(~b2)), 1U);	\
+	a2 = rotlFixed(b2 ^ (b0|(~a1)), 22U);\
+	a1 ^= (b2|(~b0));				\
+}
+
+// thanks to Paulo Barreto for this optimized theta()
+#define theta(a0, a1, a2)									\
+{ 															\
+	word32 b0, b1, c; 										\
+	c = a0 ^ a1 ^ a2; 										\
+	c = rotlFixed(c, 16U) ^ rotlFixed(c, 8U);				\
+	b0 = (a0 << 24) ^ (a2 >> 8) ^ (a1 << 8) ^ (a0 >> 24); 	\
+	b1 = (a1 << 24) ^ (a0 >> 8) ^ (a2 << 8) ^ (a1 >> 24); 	\
+	a0 ^= c ^ b0; 											\
+	a1 ^= c ^ b1; 											\
+	a2 ^= c ^ (b0 >> 16) ^ (b1 << 16); 						\
+}															
+
+#define rho(a0, a1, a2)			\
+{								\
+	theta(a0, a1, a2);			\
+	pi_gamma_pi(a0, a1, a2);	\
+}											
+
+void ThreeWay::Base::UncheckedSetKey(CipherDir dir, const byte *uk, unsigned int length, unsigned int r)
+{
+	AssertValidKeyLength(length);
+	AssertValidRounds(r);
+
+	m_rounds = r;
+
+	for (unsigned int i=0; i<3; i++)
+		m_k[i] = (word32)uk[4*i+3] | ((word32)uk[4*i+2]<<8) | ((word32)uk[4*i+1]<<16) | ((word32)uk[4*i]<<24);
+
+	if (dir == DECRYPTION)
+	{
+		theta(m_k[0], m_k[1], m_k[2]);
+		mu(m_k[0], m_k[1], m_k[2]);
+		m_k[0] = ByteReverse(m_k[0]);
+		m_k[1] = ByteReverse(m_k[1]);
+		m_k[2] = ByteReverse(m_k[2]);
+	}
+}
+
+void ThreeWay::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+	typedef BlockGetAndPut<word32, BigEndian> Block;
+
+	word32 a0, a1, a2;
+	Block::Get(inBlock)(a0)(a1)(a2);
+
+	word32 rc = START_E;
+
+	for(unsigned i=0; i<m_rounds; i++)
+	{
+		a0 ^= m_k[0] ^ (rc<<16);
+		a1 ^= m_k[1];
+		a2 ^= m_k[2] ^ rc;
+		rho(a0, a1, a2);
+
+		rc <<= 1;
+		if (rc&0x10000) rc ^= 0x11011;
+	}
+	a0 ^= m_k[0] ^ (rc<<16);
+	a1 ^= m_k[1];
+	a2 ^= m_k[2] ^ rc;
+	theta(a0, a1, a2);
+
+	Block::Put(xorBlock, outBlock)(a0)(a1)(a2);
+}
+
+void ThreeWay::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+	typedef BlockGetAndPut<word32, LittleEndian> Block;
+
+	word32 a0, a1, a2;
+	Block::Get(inBlock)(a0)(a1)(a2);
+
+	word32 rc = START_D;
+
+	mu(a0, a1, a2);
+	for(unsigned i=0; i<m_rounds; i++)
+	{
+		a0 ^= m_k[0] ^ (rc<<16);
+		a1 ^= m_k[1];
+		a2 ^= m_k[2] ^ rc;
+		rho(a0, a1, a2);
+
+		rc <<= 1;
+		if (rc&0x10000) rc ^= 0x11011;
+	}
+	a0 ^= m_k[0] ^ (rc<<16);
+	a1 ^= m_k[1];
+	a2 ^= m_k[2] ^ rc;
+	theta(a0, a1, a2);
+	mu(a0, a1, a2);
+
+	Block::Put(xorBlock, outBlock)(a0)(a1)(a2);
+}
+
+NAMESPACE_END
-- 
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