First Commit

externals/cryptopp/mars.cpp

@@ -0,0 +1,154 @@
+// mars.cpp - originally written and placed in the public domain by Wei Dai
+
+// includes IBM's key setup "tweak" proposed in August 1999 (http://www.research.ibm.com/security/key-setup.txt)
+
+#include "pch.h"
+#include "mars.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void MARS::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
+{
+	AssertValidKeyLength(length);
+
+	// Initialize T[] with the key data
+	FixedSizeSecBlock<word32, 15> T;
+	GetUserKey(LITTLE_ENDIAN_ORDER, T.begin(), 15, userKey, length);
+	T[length/4] = length/4;
+
+	for (unsigned int j=0; j<4; j++)	// compute 10 words of K[] in each iteration
+	{
+		unsigned int i;
+		// Do linear transformation
+		for (i=0; i<15; i++)
+			T[i] = T[i] ^ rotlConstant<3>(T[(i + 8) % 15] ^ T[(i + 13) % 15]) ^ (4 * i + j);
+
+		// Do four rounds of stirring
+		for (unsigned int k=0; k<4; k++)
+			for (i=0; i<15; i++)
+				T[i] = rotlConstant<9>(T[i] + Sbox[T[(i + 14) % 15] % 512]);
+
+		// Store next 10 key words into K[]
+		for (i=0; i<10; i++)
+			m_k[10*j+i] = T[4*i%15];
+	}
+
+	// Modify multiplication key-words
+	for(unsigned int i = 5; i < 37; i += 2)
+	{
+		word32 m, w = m_k[i] | 3;
+		m = (~w ^ (w<<1)) & (~w ^ (w>>1)) & 0x7ffffffe;
+		m &= m>>1; m &= m>>2; m &= m>>4;
+		m |= m<<1; m |= m<<2; m |= m<<4;
+		m &= 0x7ffffffc;
+		w ^= rotlMod(Sbox[265 + (m_k[i] & 3)], m_k[i-1]) & m;
+		m_k[i] = w;
+	}
+}
+
+#define S(a)	Sbox[(a)&0x1ff]
+#define S0(a)	Sbox[(a)&0xff]
+#define S1(a)	Sbox[((a)&0xff) + 256]
+
+typedef BlockGetAndPut<word32, LittleEndian> Block;
+
+void MARS::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+	unsigned int i;
+	word32 a, b, c, d, l, m, r, t;
+	const word32 *k = m_k;
+
+	Block::Get(inBlock)(a)(b)(c)(d);
+
+	a += k[0];	b += k[1];	c += k[2];	d += k[3];
+
+	for (i=0; i<8; i++)
+	{
+		b = (b ^ S0(a)) + S1(a>>8);
+		c += S0(a>>16);
+		a = rotrConstant<24>(a);
+		d ^= S1(a);
+		a += (i%4==0) ? d : 0;
+		a += (i%4==1) ? b : 0;
+		t = a;	a = b;	b = c;	c = d;	d = t;
+	}
+
+	for (i=0; i<16; i++)
+	{
+		t = rotlConstant<13>(a);
+		r = rotlConstant<10>(t * k[2 * i + 5]);
+		m = a + k[2*i+4];
+		l = rotlMod((S(m) ^ rotrConstant<5>(r) ^ r), r);
+		c += rotlMod(m, rotrConstant<5>(r));
+		(i<8 ? b : d) += l;
+		(i<8 ? d : b) ^= r;
+		a = b;	b = c;	c = d;	d = t;
+	}
+
+	for (i=0; i<8; i++)
+	{
+		a -= (i%4==2) ? d : 0;
+		a -= (i%4==3) ? b : 0;
+		b ^= S1(a);
+		c -= S0(a>>24);
+		t = rotlConstant<24>(a);
+		d = (d - S1(a>>16)) ^ S0(t);
+		a = b;	b = c;	c = d;	d = t;
+	}
+
+	a -= k[36];	b -= k[37];	c -= k[38];	d -= k[39];
+
+	Block::Put(xorBlock, outBlock)(a)(b)(c)(d);
+}
+
+void MARS::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+	unsigned int i;
+	word32 a, b, c, d, l, m, r, t;
+	const word32 *k = m_k;
+
+	Block::Get(inBlock)(d)(c)(b)(a);
+
+	d += k[36];	c += k[37];	b += k[38];	a += k[39];
+
+	for (i=0; i<8; i++)
+	{
+		b = (b ^ S0(a)) + S1(a>>8);
+		c += S0(a>>16);
+		a = rotrConstant<24>(a);
+		d ^= S1(a);
+		a += (i%4==0) ? d : 0;
+		a += (i%4==1) ? b : 0;
+		t = a;	a = b;	b = c;	c = d;	d = t;
+	}
+
+	for (i=0; i<16; i++)
+	{
+		t = rotrConstant<13>(a);
+		r = rotlConstant<10>(a * k[35 - 2 * i]);
+		m = t + k[34-2*i];
+		l = rotlMod((S(m) ^ rotrConstant<5>(r) ^ r), r);
+		c -= rotlMod(m, rotrConstant<5>(r));
+		(i<8 ? b : d) -= l;
+		(i<8 ? d : b) ^= r;
+		a = b;	b = c;	c = d;	d = t;
+	}
+
+	for (i=0; i<8; i++)
+	{
+		a -= (i%4==2) ? d : 0;
+		a -= (i%4==3) ? b : 0;
+		b ^= S1(a);
+		c -= S0(a>>24);
+		t = rotlConstant<24>(a);
+		d = (d - S1(a>>16)) ^ S0(t);
+		a = b;	b = c;	c = d;	d = t;
+	}
+
+	d -= k[0];	c -= k[1];	b -= k[2];	a -= k[3];
+
+	Block::Put(xorBlock, outBlock)(d)(c)(b)(a);
+}
+
+NAMESPACE_END