1 files changed, 0 insertions, 882 deletions

diff --git a/lib/cryptopp/gf2n.cpp b/lib/cryptopp/gf2n.cpp
deleted file mode 100644
index bcc56071a..000000000
--- a/lib/cryptopp/gf2n.cpp
+++ /dev/null
@@ -1,882 +0,0 @@
-// gf2n.cpp - written and placed in the public domain by Wei Dai
-
-#include "pch.h"
-
-#ifndef CRYPTOPP_IMPORTS
-
-#include "gf2n.h"
-#include "algebra.h"
-#include "words.h"
-#include "randpool.h"
-#include "asn.h"
-#include "oids.h"
-
-#include <iostream>
-
-NAMESPACE_BEGIN(CryptoPP)
-
-PolynomialMod2::PolynomialMod2()
-{
-}
-
-PolynomialMod2::PolynomialMod2(word value, size_t bitLength)
-	: reg(BitsToWords(bitLength))
-{
-	assert(value==0 || reg.size()>0);
-
-	if (reg.size() > 0)
-	{
-		reg[0] = value;
-		SetWords(reg+1, 0, reg.size()-1);
-	}
-}
-
-PolynomialMod2::PolynomialMod2(const PolynomialMod2& t)
-	: reg(t.reg.size())
-{
-	CopyWords(reg, t.reg, reg.size());
-}
-
-void PolynomialMod2::Randomize(RandomNumberGenerator &rng, size_t nbits)
-{
-	const size_t nbytes = nbits/8 + 1;
-	SecByteBlock buf(nbytes);
-	rng.GenerateBlock(buf, nbytes);
-	buf[0] = (byte)Crop(buf[0], nbits % 8);
-	Decode(buf, nbytes);
-}
-
-PolynomialMod2 PolynomialMod2::AllOnes(size_t bitLength)
-{
-	PolynomialMod2 result((word)0, bitLength);
-	SetWords(result.reg, ~(word)0, result.reg.size());
-	if (bitLength%WORD_BITS)
-		result.reg[result.reg.size()-1] = (word)Crop(result.reg[result.reg.size()-1], bitLength%WORD_BITS);
-	return result;
-}
-
-void PolynomialMod2::SetBit(size_t n, int value)
-{
-	if (value)
-	{
-		reg.CleanGrow(n/WORD_BITS + 1);
-		reg[n/WORD_BITS] |= (word(1) << (n%WORD_BITS));
-	}
-	else
-	{
-		if (n/WORD_BITS < reg.size())
-			reg[n/WORD_BITS] &= ~(word(1) << (n%WORD_BITS));
-	}
-}
-
-byte PolynomialMod2::GetByte(size_t n) const
-{
-	if (n/WORD_SIZE >= reg.size())
-		return 0;
-	else
-		return byte(reg[n/WORD_SIZE] >> ((n%WORD_SIZE)*8));
-}
-
-void PolynomialMod2::SetByte(size_t n, byte value)
-{
-	reg.CleanGrow(BytesToWords(n+1));
-	reg[n/WORD_SIZE] &= ~(word(0xff) << 8*(n%WORD_SIZE));
-	reg[n/WORD_SIZE] |= (word(value) << 8*(n%WORD_SIZE));
-}
-
-PolynomialMod2 PolynomialMod2::Monomial(size_t i) 
-{
-	PolynomialMod2 r((word)0, i+1); 
-	r.SetBit(i); 
-	return r;
-}
-
-PolynomialMod2 PolynomialMod2::Trinomial(size_t t0, size_t t1, size_t t2) 
-{
-	PolynomialMod2 r((word)0, t0+1);
-	r.SetBit(t0);
-	r.SetBit(t1);
-	r.SetBit(t2);
-	return r;
-}
-
-PolynomialMod2 PolynomialMod2::Pentanomial(size_t t0, size_t t1, size_t t2, size_t t3, size_t t4)
-{
-	PolynomialMod2 r((word)0, t0+1);
-	r.SetBit(t0);
-	r.SetBit(t1);
-	r.SetBit(t2);
-	r.SetBit(t3);
-	r.SetBit(t4);
-	return r;
-}
-
-template <word i>
-struct NewPolynomialMod2
-{
-	PolynomialMod2 * operator()() const
-	{
-		return new PolynomialMod2(i);
-	}
-};
-
-const PolynomialMod2 &PolynomialMod2::Zero()
-{
-	return Singleton<PolynomialMod2>().Ref();
-}
-
-const PolynomialMod2 &PolynomialMod2::One()
-{
-	return Singleton<PolynomialMod2, NewPolynomialMod2<1> >().Ref();
-}
-
-void PolynomialMod2::Decode(const byte *input, size_t inputLen)
-{
-	StringStore store(input, inputLen);
-	Decode(store, inputLen);
-}
-
-void PolynomialMod2::Encode(byte *output, size_t outputLen) const
-{
-	ArraySink sink(output, outputLen);
-	Encode(sink, outputLen);
-}
-
-void PolynomialMod2::Decode(BufferedTransformation &bt, size_t inputLen)
-{
-	reg.CleanNew(BytesToWords(inputLen));
-
-	for (size_t i=inputLen; i > 0; i--)
-	{
-		byte b;
-		bt.Get(b);
-		reg[(i-1)/WORD_SIZE] |= word(b) << ((i-1)%WORD_SIZE)*8;
-	}
-}
-
-void PolynomialMod2::Encode(BufferedTransformation &bt, size_t outputLen) const
-{
-	for (size_t i=outputLen; i > 0; i--)
-		bt.Put(GetByte(i-1));
-}
-
-void PolynomialMod2::DEREncodeAsOctetString(BufferedTransformation &bt, size_t length) const
-{
-	DERGeneralEncoder enc(bt, OCTET_STRING);
-	Encode(enc, length);
-	enc.MessageEnd();
-}
-
-void PolynomialMod2::BERDecodeAsOctetString(BufferedTransformation &bt, size_t length)
-{
-	BERGeneralDecoder dec(bt, OCTET_STRING);
-	if (!dec.IsDefiniteLength() || dec.RemainingLength() != length)
-		BERDecodeError();
-	Decode(dec, length);
-	dec.MessageEnd();
-}
-
-unsigned int PolynomialMod2::WordCount() const
-{
-	return (unsigned int)CountWords(reg, reg.size());
-}
-
-unsigned int PolynomialMod2::ByteCount() const
-{
-	unsigned wordCount = WordCount();
-	if (wordCount)
-		return (wordCount-1)*WORD_SIZE + BytePrecision(reg[wordCount-1]);
-	else
-		return 0;
-}
-
-unsigned int PolynomialMod2::BitCount() const
-{
-	unsigned wordCount = WordCount();
-	if (wordCount)
-		return (wordCount-1)*WORD_BITS + BitPrecision(reg[wordCount-1]);
-	else
-		return 0;
-}
-
-unsigned int PolynomialMod2::Parity() const
-{
-	unsigned i;
-	word temp=0;
-	for (i=0; i<reg.size(); i++)
-		temp ^= reg[i];
-	return CryptoPP::Parity(temp);
-}
-
-PolynomialMod2& PolynomialMod2::operator=(const PolynomialMod2& t)
-{
-	reg.Assign(t.reg);
-	return *this;
-}
-
-PolynomialMod2& PolynomialMod2::operator^=(const PolynomialMod2& t)
-{
-	reg.CleanGrow(t.reg.size());
-	XorWords(reg, t.reg, t.reg.size());
-	return *this;
-}
-
-PolynomialMod2 PolynomialMod2::Xor(const PolynomialMod2 &b) const
-{
-	if (b.reg.size() >= reg.size())
-	{
-		PolynomialMod2 result((word)0, b.reg.size()*WORD_BITS);
-		XorWords(result.reg, reg, b.reg, reg.size());
-		CopyWords(result.reg+reg.size(), b.reg+reg.size(), b.reg.size()-reg.size());
-		return result;
-	}
-	else
-	{
-		PolynomialMod2 result((word)0, reg.size()*WORD_BITS);
-		XorWords(result.reg, reg, b.reg, b.reg.size());
-		CopyWords(result.reg+b.reg.size(), reg+b.reg.size(), reg.size()-b.reg.size());
-		return result;
-	}
-}
-
-PolynomialMod2 PolynomialMod2::And(const PolynomialMod2 &b) const
-{
-	PolynomialMod2 result((word)0, WORD_BITS*STDMIN(reg.size(), b.reg.size()));
-	AndWords(result.reg, reg, b.reg, result.reg.size());
-	return result;
-}
-
-PolynomialMod2 PolynomialMod2::Times(const PolynomialMod2 &b) const
-{
-	PolynomialMod2 result((word)0, BitCount() + b.BitCount());
-
-	for (int i=b.Degree(); i>=0; i--)
-	{
-		result <<= 1;
-		if (b[i])
-			XorWords(result.reg, reg, reg.size());
-	}
-	return result;
-}
-
-PolynomialMod2 PolynomialMod2::Squared() const
-{
-	static const word map[16] = {0, 1, 4, 5, 16, 17, 20, 21, 64, 65, 68, 69, 80, 81, 84, 85};
-
-	PolynomialMod2 result((word)0, 2*reg.size()*WORD_BITS);
-
-	for (unsigned i=0; i<reg.size(); i++)
-	{
-		unsigned j;
-
-		for (j=0; j<WORD_BITS; j+=8)
-			result.reg[2*i] |= map[(reg[i] >> (j/2)) % 16] << j;
-
-		for (j=0; j<WORD_BITS; j+=8)
-			result.reg[2*i+1] |= map[(reg[i] >> (j/2 + WORD_BITS/2)) % 16] << j;
-	}
-
-	return result;
-}
-
-void PolynomialMod2::Divide(PolynomialMod2 &remainder, PolynomialMod2 &quotient,
-				   const PolynomialMod2 &dividend, const PolynomialMod2 &divisor)
-{
-	if (!divisor)
-		throw PolynomialMod2::DivideByZero();
-
-	int degree = divisor.Degree();
-	remainder.reg.CleanNew(BitsToWords(degree+1));
-	if (dividend.BitCount() >= divisor.BitCount())
-		quotient.reg.CleanNew(BitsToWords(dividend.BitCount() - divisor.BitCount() + 1));
-	else
-		quotient.reg.CleanNew(0);
-
-	for (int i=dividend.Degree(); i>=0; i--)
-	{
-		remainder <<= 1;
-		remainder.reg[0] |= dividend[i];
-		if (remainder[degree])
-		{
-			remainder -= divisor;
-			quotient.SetBit(i);
-		}
-	}
-}
-
-PolynomialMod2 PolynomialMod2::DividedBy(const PolynomialMod2 &b) const
-{
-	PolynomialMod2 remainder, quotient;
-	PolynomialMod2::Divide(remainder, quotient, *this, b);
-	return quotient;
-}
-
-PolynomialMod2 PolynomialMod2::Modulo(const PolynomialMod2 &b) const
-{
-	PolynomialMod2 remainder, quotient;
-	PolynomialMod2::Divide(remainder, quotient, *this, b);
-	return remainder;
-}
-
-PolynomialMod2& PolynomialMod2::operator<<=(unsigned int n)
-{
-	if (!reg.size())
-		return *this;
-
-	int i;
-	word u;
-	word carry=0;
-	word *r=reg;
-
-	if (n==1)	// special case code for most frequent case
-	{
-		i = (int)reg.size();
-		while (i--)
-		{
-			u = *r;
-			*r = (u << 1) | carry;
-			carry = u >> (WORD_BITS-1);
-			r++;
-		}
-
-		if (carry)
-		{
-			reg.Grow(reg.size()+1);
-			reg[reg.size()-1] = carry;
-		}
-
-		return *this;
-	}
-
-	int shiftWords = n / WORD_BITS;
-	int shiftBits = n % WORD_BITS;
-
-	if (shiftBits)
-	{
-		i = (int)reg.size();
-		while (i--)
-		{
-			u = *r;
-			*r = (u << shiftBits) | carry;
-			carry = u >> (WORD_BITS-shiftBits);
-			r++;
-		}
-	}
-
-	if (carry)
-	{
-		reg.Grow(reg.size()+shiftWords+1);
-		reg[reg.size()-1] = carry;
-	}
-	else
-		reg.Grow(reg.size()+shiftWords);
-
-	if (shiftWords)
-	{
-		for (i = (int)reg.size()-1; i>=shiftWords; i--)
-			reg[i] = reg[i-shiftWords];
-		for (; i>=0; i--)
-			reg[i] = 0;
-	}
-
-	return *this;
-}
-
-PolynomialMod2& PolynomialMod2::operator>>=(unsigned int n)
-{
-	if (!reg.size())
-		return *this;
-
-	int shiftWords = n / WORD_BITS;
-	int shiftBits = n % WORD_BITS;
-
-	size_t i;
-	word u;
-	word carry=0;
-	word *r=reg+reg.size()-1;
-
-	if (shiftBits)
-	{
-		i = reg.size();
-		while (i--)
-		{
-			u = *r;
-			*r = (u >> shiftBits) | carry;
-			carry = u << (WORD_BITS-shiftBits);
-			r--;
-		}
-	}
-
-	if (shiftWords)
-	{
-		for (i=0; i<reg.size()-shiftWords; i++)
-			reg[i] = reg[i+shiftWords];
-		for (; i<reg.size(); i++)
-			reg[i] = 0;
-	}
-
-	return *this;
-}
-
-PolynomialMod2 PolynomialMod2::operator<<(unsigned int n) const
-{
-	PolynomialMod2 result(*this);
-	return result<<=n;
-}
-
-PolynomialMod2 PolynomialMod2::operator>>(unsigned int n) const
-{
-	PolynomialMod2 result(*this);
-	return result>>=n;
-}
-
-bool PolynomialMod2::operator!() const
-{
-	for (unsigned i=0; i<reg.size(); i++)
-		if (reg[i]) return false;
-	return true;
-}
-
-bool PolynomialMod2::Equals(const PolynomialMod2 &rhs) const
-{
-	size_t i, smallerSize = STDMIN(reg.size(), rhs.reg.size());
-
-	for (i=0; i<smallerSize; i++)
-		if (reg[i] != rhs.reg[i]) return false;
-
-	for (i=smallerSize; i<reg.size(); i++)
-		if (reg[i] != 0) return false;
-
-	for (i=smallerSize; i<rhs.reg.size(); i++)
-		if (rhs.reg[i] != 0) return false;
-
-	return true;
-}
-
-std::ostream& operator<<(std::ostream& out, const PolynomialMod2 &a)
-{
-	// Get relevant conversion specifications from ostream.
-	long f = out.flags() & std::ios::basefield;	// Get base digits.
-	int bits, block;
-	char suffix;
-	switch(f)
-	{
-	case std::ios::oct :
-		bits = 3;
-		block = 4;
-		suffix = 'o';
-		break;
-	case std::ios::hex :
-		bits = 4;
-		block = 2;
-		suffix = 'h';
-		break;
-	default :
-		bits = 1;
-		block = 8;
-		suffix = 'b';
-	}
-
-	if (!a)
-		return out << '0' << suffix;
-
-	SecBlock<char> s(a.BitCount()/bits+1);
-	unsigned i;
-
-	static const char upper[]="0123456789ABCDEF";
-	static const char lower[]="0123456789abcdef";
-	const char* vec = (out.flags() & std::ios::uppercase) ? upper : lower;
-
-	for (i=0; i*bits < a.BitCount(); i++)
-	{
-		int digit=0;
-		for (int j=0; j<bits; j++)
-			digit |= a[i*bits+j] << j;
-		s[i]=vec[digit];
-	}
-
-	while (i--)
-	{
-		out << s[i];
-		if (i && (i%block)==0)
-			out << ',';
-	}
-
-	return out << suffix;
-}
-
-PolynomialMod2 PolynomialMod2::Gcd(const PolynomialMod2 &a, const PolynomialMod2 &b)
-{
-	return EuclideanDomainOf<PolynomialMod2>().Gcd(a, b);
-}
-
-PolynomialMod2 PolynomialMod2::InverseMod(const PolynomialMod2 &modulus) const
-{
-	typedef EuclideanDomainOf<PolynomialMod2> Domain;
-	return QuotientRing<Domain>(Domain(), modulus).MultiplicativeInverse(*this);
-}
-
-bool PolynomialMod2::IsIrreducible() const
-{
-	signed int d = Degree();
-	if (d <= 0)
-		return false;
-
-	PolynomialMod2 t(2), u(t);
-	for (int i=1; i<=d/2; i++)
-	{
-		u = u.Squared()%(*this);
-		if (!Gcd(u+t, *this).IsUnit())
-			return false;
-	}
-	return true;
-}
-
-// ********************************************************
-
-GF2NP::GF2NP(const PolynomialMod2 &modulus)
-	: QuotientRing<EuclideanDomainOf<PolynomialMod2> >(EuclideanDomainOf<PolynomialMod2>(), modulus), m(modulus.Degree()) 
-{
-}
-
-GF2NP::Element GF2NP::SquareRoot(const Element &a) const
-{
-	Element r = a;
-	for (unsigned int i=1; i<m; i++)
-		r = Square(r);
-	return r;
-}
-
-GF2NP::Element GF2NP::HalfTrace(const Element &a) const
-{
-	assert(m%2 == 1);
-	Element h = a;
-	for (unsigned int i=1; i<=(m-1)/2; i++)
-		h = Add(Square(Square(h)), a);
-	return h;
-}
-
-GF2NP::Element GF2NP::SolveQuadraticEquation(const Element &a) const
-{
-	if (m%2 == 0)
-	{
-		Element z, w;
-		RandomPool rng;
-		do
-		{
-			Element p((RandomNumberGenerator &)rng, m);
-			z = PolynomialMod2::Zero();
-			w = p;
-			for (unsigned int i=1; i<=m-1; i++)
-			{
-				w = Square(w);
-				z = Square(z);
-				Accumulate(z, Multiply(w, a));
-				Accumulate(w, p);
-			}
-		} while (w.IsZero());
-		return z;
-	}
-	else
-		return HalfTrace(a);
-}
-
-// ********************************************************
-
-GF2NT::GF2NT(unsigned int t0, unsigned int t1, unsigned int t2)
-	: GF2NP(PolynomialMod2::Trinomial(t0, t1, t2))
-	, t0(t0), t1(t1)
-	, result((word)0, m)
-{
-	assert(t0 > t1 && t1 > t2 && t2==0);
-}
-
-const GF2NT::Element& GF2NT::MultiplicativeInverse(const Element &a) const
-{
-	if (t0-t1 < WORD_BITS)
-		return GF2NP::MultiplicativeInverse(a);
-
-	SecWordBlock T(m_modulus.reg.size() * 4);
-	word *b = T;
-	word *c = T+m_modulus.reg.size();
-	word *f = T+2*m_modulus.reg.size();
-	word *g = T+3*m_modulus.reg.size();
-	size_t bcLen=1, fgLen=m_modulus.reg.size();
-	unsigned int k=0;
-
-	SetWords(T, 0, 3*m_modulus.reg.size());
-	b[0]=1;
-	assert(a.reg.size() <= m_modulus.reg.size());
-	CopyWords(f, a.reg, a.reg.size());
-	CopyWords(g, m_modulus.reg, m_modulus.reg.size());
-
-	while (1)
-	{
-		word t=f[0];
-		while (!t)
-		{
-			ShiftWordsRightByWords(f, fgLen, 1);
-			if (c[bcLen-1])
-				bcLen++;
-			assert(bcLen <= m_modulus.reg.size());
-			ShiftWordsLeftByWords(c, bcLen, 1);
-			k+=WORD_BITS;
-			t=f[0];
-		}
-
-		unsigned int i=0;
-		while (t%2 == 0)
-		{
-			t>>=1;
-			i++;
-		}
-		k+=i;
-
-		if (t==1 && CountWords(f, fgLen)==1)
-			break;
-
-		if (i==1)
-		{
-			ShiftWordsRightByBits(f, fgLen, 1);
-			t=ShiftWordsLeftByBits(c, bcLen, 1);
-		}
-		else
-		{
-			ShiftWordsRightByBits(f, fgLen, i);
-			t=ShiftWordsLeftByBits(c, bcLen, i);
-		}
-		if (t)
-		{
-			c[bcLen] = t;
-			bcLen++;
-			assert(bcLen <= m_modulus.reg.size());
-		}
-
-		if (f[fgLen-1]==0 && g[fgLen-1]==0)
-			fgLen--;
-
-		if (f[fgLen-1] < g[fgLen-1])
-		{
-			std::swap(f, g);
-			std::swap(b, c);
-		}
-
-		XorWords(f, g, fgLen);
-		XorWords(b, c, bcLen);
-	}
-
-	while (k >= WORD_BITS)
-	{
-		word temp = b[0];
-		// right shift b
-		for (unsigned i=0; i+1<BitsToWords(m); i++)
-			b[i] = b[i+1];
-		b[BitsToWords(m)-1] = 0;
-
-		if (t1 < WORD_BITS)
-			for (unsigned int j=0; j<WORD_BITS-t1; j++)
-				temp ^= ((temp >> j) & 1) << (t1 + j);
-		else
-			b[t1/WORD_BITS-1] ^= temp << t1%WORD_BITS;
-
-		if (t1 % WORD_BITS)
-			b[t1/WORD_BITS] ^= temp >> (WORD_BITS - t1%WORD_BITS);
-
-		if (t0%WORD_BITS)
-		{
-			b[t0/WORD_BITS-1] ^= temp << t0%WORD_BITS;
-			b[t0/WORD_BITS] ^= temp >> (WORD_BITS - t0%WORD_BITS);
-		}
-		else
-			b[t0/WORD_BITS-1] ^= temp;
-
-		k -= WORD_BITS;
-	}
-
-	if (k)
-	{
-		word temp = b[0] << (WORD_BITS - k);
-		ShiftWordsRightByBits(b, BitsToWords(m), k);
-
-		if (t1 < WORD_BITS)
-			for (unsigned int j=0; j<WORD_BITS-t1; j++)
-				temp ^= ((temp >> j) & 1) << (t1 + j);
-		else
-			b[t1/WORD_BITS-1] ^= temp << t1%WORD_BITS;
-
-		if (t1 % WORD_BITS)
-			b[t1/WORD_BITS] ^= temp >> (WORD_BITS - t1%WORD_BITS);
-
-		if (t0%WORD_BITS)
-		{
-			b[t0/WORD_BITS-1] ^= temp << t0%WORD_BITS;
-			b[t0/WORD_BITS] ^= temp >> (WORD_BITS - t0%WORD_BITS);
-		}
-		else
-			b[t0/WORD_BITS-1] ^= temp;
-	}
-
-	CopyWords(result.reg.begin(), b, result.reg.size());
-	return result;
-}
-
-const GF2NT::Element& GF2NT::Multiply(const Element &a, const Element &b) const
-{
-	size_t aSize = STDMIN(a.reg.size(), result.reg.size());
-	Element r((word)0, m);
-
-	for (int i=m-1; i>=0; i--)
-	{
-		if (r[m-1])
-		{
-			ShiftWordsLeftByBits(r.reg.begin(), r.reg.size(), 1);
-			XorWords(r.reg.begin(), m_modulus.reg, r.reg.size());
-		}
-		else
-			ShiftWordsLeftByBits(r.reg.begin(), r.reg.size(), 1);
-
-		if (b[i])
-			XorWords(r.reg.begin(), a.reg, aSize);
-	}
-
-	if (m%WORD_BITS)
-		r.reg.begin()[r.reg.size()-1] = (word)Crop(r.reg[r.reg.size()-1], m%WORD_BITS);
-
-	CopyWords(result.reg.begin(), r.reg.begin(), result.reg.size());
-	return result;
-}
-
-const GF2NT::Element& GF2NT::Reduced(const Element &a) const
-{
-	if (t0-t1 < WORD_BITS)
-		return m_domain.Mod(a, m_modulus);
-
-	SecWordBlock b(a.reg);
-
-	size_t i;
-	for (i=b.size()-1; i>=BitsToWords(t0); i--)
-	{
-		word temp = b[i];
-
-		if (t0%WORD_BITS)
-		{
-			b[i-t0/WORD_BITS] ^= temp >> t0%WORD_BITS;
-			b[i-t0/WORD_BITS-1] ^= temp << (WORD_BITS - t0%WORD_BITS);
-		}
-		else
-			b[i-t0/WORD_BITS] ^= temp;
-
-		if ((t0-t1)%WORD_BITS)
-		{
-			b[i-(t0-t1)/WORD_BITS] ^= temp >> (t0-t1)%WORD_BITS;
-			b[i-(t0-t1)/WORD_BITS-1] ^= temp << (WORD_BITS - (t0-t1)%WORD_BITS);
-		}
-		else
-			b[i-(t0-t1)/WORD_BITS] ^= temp;
-	}
-
-	if (i==BitsToWords(t0)-1 && t0%WORD_BITS)
-	{
-		word mask = ((word)1<<(t0%WORD_BITS))-1;
-		word temp = b[i] & ~mask;
-		b[i] &= mask;
-
-		b[i-t0/WORD_BITS] ^= temp >> t0%WORD_BITS;
-
-		if ((t0-t1)%WORD_BITS)
-		{
-			b[i-(t0-t1)/WORD_BITS] ^= temp >> (t0-t1)%WORD_BITS;
-			if ((t0-t1)%WORD_BITS > t0%WORD_BITS)
-				b[i-(t0-t1)/WORD_BITS-1] ^= temp << (WORD_BITS - (t0-t1)%WORD_BITS);
-			else
-				assert(temp << (WORD_BITS - (t0-t1)%WORD_BITS) == 0);
-		}
-		else
-			b[i-(t0-t1)/WORD_BITS] ^= temp;
-	}
-
-	SetWords(result.reg.begin(), 0, result.reg.size());
-	CopyWords(result.reg.begin(), b, STDMIN(b.size(), result.reg.size()));
-	return result;
-}
-
-void GF2NP::DEREncodeElement(BufferedTransformation &out, const Element &a) const
-{
-	a.DEREncodeAsOctetString(out, MaxElementByteLength());
-}
-
-void GF2NP::BERDecodeElement(BufferedTransformation &in, Element &a) const
-{
-	a.BERDecodeAsOctetString(in, MaxElementByteLength());
-}
-
-void GF2NT::DEREncode(BufferedTransformation &bt) const
-{
-	DERSequenceEncoder seq(bt);
-		ASN1::characteristic_two_field().DEREncode(seq);
-		DERSequenceEncoder parameters(seq);
-			DEREncodeUnsigned(parameters, m);
-			ASN1::tpBasis().DEREncode(parameters);
-			DEREncodeUnsigned(parameters, t1);
-		parameters.MessageEnd();
-	seq.MessageEnd();
-}
-
-void GF2NPP::DEREncode(BufferedTransformation &bt) const
-{
-	DERSequenceEncoder seq(bt);
-		ASN1::characteristic_two_field().DEREncode(seq);
-		DERSequenceEncoder parameters(seq);
-			DEREncodeUnsigned(parameters, m);
-			ASN1::ppBasis().DEREncode(parameters);
-			DERSequenceEncoder pentanomial(parameters);
-				DEREncodeUnsigned(pentanomial, t3);
-				DEREncodeUnsigned(pentanomial, t2);
-				DEREncodeUnsigned(pentanomial, t1);
-			pentanomial.MessageEnd();
-		parameters.MessageEnd();
-	seq.MessageEnd();
-}
-
-GF2NP * BERDecodeGF2NP(BufferedTransformation &bt)
-{
-	// VC60 workaround: auto_ptr lacks reset()
-	member_ptr<GF2NP> result;
-
-	BERSequenceDecoder seq(bt);
-		if (OID(seq) != ASN1::characteristic_two_field())
-			BERDecodeError();
-		BERSequenceDecoder parameters(seq);
-			unsigned int m;
-			BERDecodeUnsigned(parameters, m);
-			OID oid(parameters);
-			if (oid == ASN1::tpBasis())
-			{
-				unsigned int t1;
-				BERDecodeUnsigned(parameters, t1);
-				result.reset(new GF2NT(m, t1, 0));
-			}
-			else if (oid == ASN1::ppBasis())
-			{
-				unsigned int t1, t2, t3;
-				BERSequenceDecoder pentanomial(parameters);
-				BERDecodeUnsigned(pentanomial, t3);
-				BERDecodeUnsigned(pentanomial, t2);
-				BERDecodeUnsigned(pentanomial, t1);
-				pentanomial.MessageEnd();
-				result.reset(new GF2NPP(m, t3, t2, t1, 0));
-			}
-			else
-			{
-				BERDecodeError();
-				return NULL;
-			}
-		parameters.MessageEnd();
-	seq.MessageEnd();
-
-	return result.release();
-}
-
-NAMESPACE_END
-
-#endif