From 3438e5d3ddf8444f0e31009ffbe8237ef3752c22 Mon Sep 17 00:00:00 2001 From: Alexander Harkness Date: Sun, 24 Nov 2013 14:21:13 +0000 Subject: move cryptopp into lib --- lib/cryptopp/ecp.cpp | 473 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 473 insertions(+) create mode 100644 lib/cryptopp/ecp.cpp (limited to 'lib/cryptopp/ecp.cpp') diff --git a/lib/cryptopp/ecp.cpp b/lib/cryptopp/ecp.cpp new file mode 100644 index 000000000..55a7cc15b --- /dev/null +++ b/lib/cryptopp/ecp.cpp @@ -0,0 +1,473 @@ +// ecp.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "ecp.h" +#include "asn.h" +#include "nbtheory.h" + +#include "algebra.cpp" + +NAMESPACE_BEGIN(CryptoPP) + +ANONYMOUS_NAMESPACE_BEGIN +static inline ECP::Point ToMontgomery(const ModularArithmetic &mr, const ECP::Point &P) +{ + return P.identity ? P : ECP::Point(mr.ConvertIn(P.x), mr.ConvertIn(P.y)); +} + +static inline ECP::Point FromMontgomery(const ModularArithmetic &mr, const ECP::Point &P) +{ + return P.identity ? P : ECP::Point(mr.ConvertOut(P.x), mr.ConvertOut(P.y)); +} +NAMESPACE_END + +ECP::ECP(const ECP &ecp, bool convertToMontgomeryRepresentation) +{ + if (convertToMontgomeryRepresentation && !ecp.GetField().IsMontgomeryRepresentation()) + { + m_fieldPtr.reset(new MontgomeryRepresentation(ecp.GetField().GetModulus())); + m_a = GetField().ConvertIn(ecp.m_a); + m_b = GetField().ConvertIn(ecp.m_b); + } + else + operator=(ecp); +} + +ECP::ECP(BufferedTransformation &bt) + : m_fieldPtr(new Field(bt)) +{ + BERSequenceDecoder seq(bt); + GetField().BERDecodeElement(seq, m_a); + GetField().BERDecodeElement(seq, m_b); + // skip optional seed + if (!seq.EndReached()) + { + SecByteBlock seed; + unsigned int unused; + BERDecodeBitString(seq, seed, unused); + } + seq.MessageEnd(); +} + +void ECP::DEREncode(BufferedTransformation &bt) const +{ + GetField().DEREncode(bt); + DERSequenceEncoder seq(bt); + GetField().DEREncodeElement(seq, m_a); + GetField().DEREncodeElement(seq, m_b); + seq.MessageEnd(); +} + +bool ECP::DecodePoint(ECP::Point &P, const byte *encodedPoint, size_t encodedPointLen) const +{ + StringStore store(encodedPoint, encodedPointLen); + return DecodePoint(P, store, encodedPointLen); +} + +bool ECP::DecodePoint(ECP::Point &P, BufferedTransformation &bt, size_t encodedPointLen) const +{ + byte type; + if (encodedPointLen < 1 || !bt.Get(type)) + return false; + + switch (type) + { + case 0: + P.identity = true; + return true; + case 2: + case 3: + { + if (encodedPointLen != EncodedPointSize(true)) + return false; + + Integer p = FieldSize(); + + P.identity = false; + P.x.Decode(bt, GetField().MaxElementByteLength()); + P.y = ((P.x*P.x+m_a)*P.x+m_b) % p; + + if (Jacobi(P.y, p) !=1) + return false; + + P.y = ModularSquareRoot(P.y, p); + + if ((type & 1) != P.y.GetBit(0)) + P.y = p-P.y; + + return true; + } + case 4: + { + if (encodedPointLen != EncodedPointSize(false)) + return false; + + unsigned int len = GetField().MaxElementByteLength(); + P.identity = false; + P.x.Decode(bt, len); + P.y.Decode(bt, len); + return true; + } + default: + return false; + } +} + +void ECP::EncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const +{ + if (P.identity) + NullStore().TransferTo(bt, EncodedPointSize(compressed)); + else if (compressed) + { + bt.Put(2 + P.y.GetBit(0)); + P.x.Encode(bt, GetField().MaxElementByteLength()); + } + else + { + unsigned int len = GetField().MaxElementByteLength(); + bt.Put(4); // uncompressed + P.x.Encode(bt, len); + P.y.Encode(bt, len); + } +} + +void ECP::EncodePoint(byte *encodedPoint, const Point &P, bool compressed) const +{ + ArraySink sink(encodedPoint, EncodedPointSize(compressed)); + EncodePoint(sink, P, compressed); + assert(sink.TotalPutLength() == EncodedPointSize(compressed)); +} + +ECP::Point ECP::BERDecodePoint(BufferedTransformation &bt) const +{ + SecByteBlock str; + BERDecodeOctetString(bt, str); + Point P; + if (!DecodePoint(P, str, str.size())) + BERDecodeError(); + return P; +} + +void ECP::DEREncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const +{ + SecByteBlock str(EncodedPointSize(compressed)); + EncodePoint(str, P, compressed); + DEREncodeOctetString(bt, str); +} + +bool ECP::ValidateParameters(RandomNumberGenerator &rng, unsigned int level) const +{ + Integer p = FieldSize(); + + bool pass = p.IsOdd(); + pass = pass && !m_a.IsNegative() && m_a

= 1) + pass = pass && ((4*m_a*m_a*m_a+27*m_b*m_b)%p).IsPositive(); + + if (level >= 2) + pass = pass && VerifyPrime(rng, p); + + return pass; +} + +bool ECP::VerifyPoint(const Point &P) const +{ + const FieldElement &x = P.x, &y = P.y; + Integer p = FieldSize(); + return P.identity || + (!x.IsNegative() && x

().Ref(); +} + +const ECP::Point& ECP::Inverse(const Point &P) const +{ + if (P.identity) + return P; + else + { + m_R.identity = false; + m_R.x = P.x; + m_R.y = GetField().Inverse(P.y); + return m_R; + } +} + +const ECP::Point& ECP::Add(const Point &P, const Point &Q) const +{ + if (P.identity) return Q; + if (Q.identity) return P; + if (GetField().Equal(P.x, Q.x)) + return GetField().Equal(P.y, Q.y) ? Double(P) : Identity(); + + FieldElement t = GetField().Subtract(Q.y, P.y); + t = GetField().Divide(t, GetField().Subtract(Q.x, P.x)); + FieldElement x = GetField().Subtract(GetField().Subtract(GetField().Square(t), P.x), Q.x); + m_R.y = GetField().Subtract(GetField().Multiply(t, GetField().Subtract(P.x, x)), P.y); + + m_R.x.swap(x); + m_R.identity = false; + return m_R; +} + +const ECP::Point& ECP::Double(const Point &P) const +{ + if (P.identity || P.y==GetField().Identity()) return Identity(); + + FieldElement t = GetField().Square(P.x); + t = GetField().Add(GetField().Add(GetField().Double(t), t), m_a); + t = GetField().Divide(t, GetField().Double(P.y)); + FieldElement x = GetField().Subtract(GetField().Subtract(GetField().Square(t), P.x), P.x); + m_R.y = GetField().Subtract(GetField().Multiply(t, GetField().Subtract(P.x, x)), P.y); + + m_R.x.swap(x); + m_R.identity = false; + return m_R; +} + +template void ParallelInvert(const AbstractRing &ring, Iterator begin, Iterator end) +{ + size_t n = end-begin; + if (n == 1) + *begin = ring.MultiplicativeInverse(*begin); + else if (n > 1) + { + std::vector vec((n+1)/2); + unsigned int i; + Iterator it; + + for (i=0, it=begin; i::iterator it) : it(it) {} + Integer& operator*() {return it->z;} + int operator-(ZIterator it2) {return int(it-it2.it);} + ZIterator operator+(int i) {return ZIterator(it+i);} + ZIterator& operator+=(int i) {it+=i; return *this;} + std::vector::iterator it; +}; + +ECP::Point ECP::ScalarMultiply(const Point &P, const Integer &k) const +{ + Element result; + if (k.BitCount() <= 5) + AbstractGroup::SimultaneousMultiply(&result, P, &k, 1); + else + ECP::SimultaneousMultiply(&result, P, &k, 1); + return result; +} + +void ECP::SimultaneousMultiply(ECP::Point *results, const ECP::Point &P, const Integer *expBegin, unsigned int expCount) const +{ + if (!GetField().IsMontgomeryRepresentation()) + { + ECP ecpmr(*this, true); + const ModularArithmetic &mr = ecpmr.GetField(); + ecpmr.SimultaneousMultiply(results, ToMontgomery(mr, P), expBegin, expCount); + for (unsigned int i=0; i bases; + std::vector exponents; + exponents.reserve(expCount); + std::vector > baseIndices(expCount); + std::vector > negateBase(expCount); + std::vector > exponentWindows(expCount); + unsigned int i; + + for (i=0; iNotNegative()); + exponents.push_back(WindowSlider(*expBegin++, InversionIsFast(), 5)); + exponents[i].FindNextWindow(); + } + + unsigned int expBitPosition = 0; + bool notDone = true; + + while (notDone) + { + notDone = false; + bool baseAdded = false; + for (i=0; i > finalCascade; + for (i=0; i::CascadeScalarMultiply(P, k1, Q, k2); +} + +NAMESPACE_END + +#endif -- cgit v1.2.3