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1 files changed, 211 insertions, 0 deletions

diff --git a/seal.cpp b/seal.cpp
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+// seal.cpp - written and placed in the public domain by Wei Dai
+// updated to SEAL 3.0 by Leonard Janke
+
+#include "pch.h"
+#include "seal.h"
+#include "sha.h"
+#include "misc.h"
+
+#include "strciphr.cpp"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void SEAL_TestInstantiations()
+{
+	SEAL<>::Encryption x;
+}
+
+struct SEAL_Gamma
+{
+	SEAL_Gamma(const byte *key)
+		: H(5), Z(5), D(16), lastIndex(0xffffffff)
+	{
+		GetUserKey(BIG_ENDIAN_ORDER, H.begin(), 5, key, 20);
+		memset(D, 0, 64);
+	}
+
+	word32 Apply(word32 i);
+
+	SecBlock<word32> H, Z, D;
+	word32 lastIndex;
+};
+
+word32 SEAL_Gamma::Apply(word32 i)
+{
+	word32 shaIndex = i/5;
+	if (shaIndex != lastIndex)
+	{
+		memcpy(Z, H, 20);
+		D[0] = shaIndex;
+		SHA::Transform(Z, D);
+		lastIndex = shaIndex;
+	}
+	return Z[i%5];
+}
+
+template <class B>
+void SEAL_Policy<B>::CipherSetKey(const NameValuePairs &params, const byte *key, unsigned int length)
+{
+	m_insideCounter = m_outsideCounter = m_startCount = 0;
+
+	unsigned int L = params.GetIntValueWithDefault("NumberOfOutputBitsPerPositionIndex", 32*1024);
+	m_iterationsPerCount = L / 8192;
+
+	SEAL_Gamma gamma(key);
+	unsigned int i;
+
+	for (i=0; i<512; i++)
+		m_T[i] = gamma.Apply(i);
+
+	for (i=0; i<256; i++)
+		m_S[i] = gamma.Apply(0x1000+i);
+
+	m_R.New(4*(L/8192));
+
+	for (i=0; i<m_R.size(); i++)
+		m_R[i] = gamma.Apply(0x2000+i);
+}
+
+template <class B>
+void SEAL_Policy<B>::CipherResynchronize(byte *keystreamBuffer, const byte *IV)
+{
+	m_outsideCounter = UnalignedGetWord<word32>(BIG_ENDIAN_ORDER, IV);
+	m_startCount = m_outsideCounter;
+	m_insideCounter = 0;
+}
+
+template <class B>
+void SEAL_Policy<B>::SeekToIteration(dword iterationCount)
+{
+	m_outsideCounter = m_startCount + iterationCount / m_iterationsPerCount;
+	m_insideCounter = iterationCount % m_iterationsPerCount;
+}
+
+template <class B>
+void SEAL_Policy<B>::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, unsigned int iterationCount)
+{
+	KeystreamOutput<B> keystreamOutput(operation, output, input);
+	word32 a, b, c, d, n1, n2, n3, n4;
+	unsigned int p, q;
+
+	for (unsigned int iteration = 0; iteration < iterationCount; ++iteration)
+	{
+#define Ttab(x) *(word32 *)((byte *)m_T.begin()+x)
+
+		a = m_outsideCounter ^ m_R[4*m_insideCounter];
+		b = rotrFixed(m_outsideCounter, 8U) ^ m_R[4*m_insideCounter+1];
+		c = rotrFixed(m_outsideCounter, 16U) ^ m_R[4*m_insideCounter+2];
+		d = rotrFixed(m_outsideCounter, 24U) ^ m_R[4*m_insideCounter+3];
+
+		for (unsigned int j=0; j<2; j++)
+		{
+			p = a & 0x7fc;
+			b += Ttab(p);
+			a = rotrFixed(a, 9U);
+
+			p = b & 0x7fc;
+			c += Ttab(p);
+			b = rotrFixed(b, 9U);
+
+			p = c & 0x7fc;
+			d += Ttab(p);
+			c = rotrFixed(c, 9U);
+
+			p = d & 0x7fc;
+			a += Ttab(p);
+			d = rotrFixed(d, 9U);
+		}
+
+		n1 = d, n2 = b, n3 = a, n4 = c;
+
+		p = a & 0x7fc;
+		b += Ttab(p);
+		a = rotrFixed(a, 9U);
+
+		p = b & 0x7fc;
+		c += Ttab(p);
+		b = rotrFixed(b, 9U);
+
+		p = c & 0x7fc;
+		d += Ttab(p);
+		c = rotrFixed(c, 9U);
+
+		p = d & 0x7fc;
+		a += Ttab(p);
+		d = rotrFixed(d, 9U);
+		
+		// generate 8192 bits
+		for (unsigned int i=0; i<64; i++)
+		{
+			p = a & 0x7fc;
+			a = rotrFixed(a, 9U);
+			b += Ttab(p);
+			b ^= a;
+
+			q = b & 0x7fc;
+			b = rotrFixed(b, 9U);
+			c ^= Ttab(q);
+			c += b;
+
+			p = (p+c) & 0x7fc;
+			c = rotrFixed(c, 9U);
+			d += Ttab(p);
+			d ^= c;
+
+			q = (q+d) & 0x7fc;
+			d = rotrFixed(d, 9U);
+			a ^= Ttab(q);
+			a += d;
+
+			p = (p+a) & 0x7fc;
+			b ^= Ttab(p);
+			a = rotrFixed(a, 9U);
+
+			q = (q+b) & 0x7fc;
+			c += Ttab(q);
+			b = rotrFixed(b, 9U);
+
+			p = (p+c) & 0x7fc;
+			d ^= Ttab(p);
+			c = rotrFixed(c, 9U);
+
+			q = (q+d) & 0x7fc;
+			d = rotrFixed(d, 9U);
+			a += Ttab(q);
+
+			keystreamOutput	(b + m_S[4*i+0])
+							(c ^ m_S[4*i+1])
+							(d + m_S[4*i+2])
+							(a ^ m_S[4*i+3]);
+
+			if (i & 1)
+			{
+				a += n3;
+				b += n4;
+				c ^= n3;
+				d ^= n4;
+			}
+			else
+			{
+				a += n1;
+				b += n2;        
+				c ^= n1;
+				d ^= n2;
+			}
+		}
+
+		if (++m_insideCounter == m_iterationsPerCount)
+		{
+			++m_outsideCounter;
+			m_insideCounter = 0;
+		}
+	}
+
+	a = b = c = d = n1 = n2 = n3 = n4 = 0;
+	p = q = 0;
+}
+
+template class SEAL_Policy<BigEndian>;
+template class SEAL_Policy<LittleEndian>;
+
+NAMESPACE_END