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Diffstat (limited to 'lib/cryptopp/gf2n.cpp')
| -rw-r--r-- | lib/cryptopp/gf2n.cpp | 882 |
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 "ient, - const PolynomialMod2 ÷nd, 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 |