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222 lines
5.5 KiB
222 lines
5.5 KiB
// rabin.cpp - written and placed in the public domain by Wei Dai |
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#include "pch.h" |
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#include "rabin.h" |
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#include "integer.h" |
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#include "nbtheory.h" |
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#include "modarith.h" |
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#include "asn.h" |
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#include "sha.h" |
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NAMESPACE_BEGIN(CryptoPP) |
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void RabinFunction::BERDecode(BufferedTransformation &bt) |
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{ |
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BERSequenceDecoder seq(bt); |
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m_n.BERDecode(seq); |
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m_r.BERDecode(seq); |
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m_s.BERDecode(seq); |
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seq.MessageEnd(); |
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} |
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void RabinFunction::DEREncode(BufferedTransformation &bt) const |
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{ |
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DERSequenceEncoder seq(bt); |
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m_n.DEREncode(seq); |
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m_r.DEREncode(seq); |
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m_s.DEREncode(seq); |
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seq.MessageEnd(); |
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} |
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Integer RabinFunction::ApplyFunction(const Integer &in) const |
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{ |
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DoQuickSanityCheck(); |
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Integer out = in.Squared()%m_n; |
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if (in.IsOdd()) |
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out = out*m_r%m_n; |
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if (Jacobi(in, m_n)==-1) |
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out = out*m_s%m_n; |
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return out; |
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} |
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bool RabinFunction::Validate(RandomNumberGenerator& /*rng*/, unsigned int level) const |
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{ |
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bool pass = true; |
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pass = pass && m_n > Integer::One() && m_n%4 == 1; |
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pass = pass && m_r > Integer::One() && m_r < m_n; |
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pass = pass && m_s > Integer::One() && m_s < m_n; |
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if (level >= 1) |
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pass = pass && Jacobi(m_r, m_n) == -1 && Jacobi(m_s, m_n) == -1; |
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return pass; |
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} |
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bool RabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const |
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{ |
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return GetValueHelper(this, name, valueType, pValue).Assignable() |
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CRYPTOPP_GET_FUNCTION_ENTRY(Modulus) |
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CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime1) |
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CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime2) |
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; |
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} |
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void RabinFunction::AssignFrom(const NameValuePairs &source) |
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{ |
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AssignFromHelper(this, source) |
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CRYPTOPP_SET_FUNCTION_ENTRY(Modulus) |
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CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime1) |
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CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime2) |
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; |
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} |
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// ***************************************************************************** |
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// private key operations: |
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// generate a random private key |
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void InvertibleRabinFunction::GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg) |
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{ |
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int modulusSize = 2048; |
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alg.GetIntValue("ModulusSize", modulusSize) || alg.GetIntValue("KeySize", modulusSize); |
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if (modulusSize < 16) |
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throw InvalidArgument("InvertibleRabinFunction: specified modulus size is too small"); |
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// VC70 workaround: putting these after primeParam causes overlapped stack allocation |
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bool rFound=false, sFound=false; |
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Integer t=2; |
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AlgorithmParameters primeParam = MakeParametersForTwoPrimesOfEqualSize(modulusSize) |
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("EquivalentTo", 3)("Mod", 4); |
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m_p.GenerateRandom(rng, primeParam); |
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m_q.GenerateRandom(rng, primeParam); |
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while (!(rFound && sFound)) |
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{ |
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int jp = Jacobi(t, m_p); |
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int jq = Jacobi(t, m_q); |
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if (!rFound && jp==1 && jq==-1) |
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{ |
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m_r = t; |
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rFound = true; |
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} |
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if (!sFound && jp==-1 && jq==1) |
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{ |
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m_s = t; |
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sFound = true; |
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} |
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++t; |
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} |
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m_n = m_p * m_q; |
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m_u = m_q.InverseMod(m_p); |
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} |
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void InvertibleRabinFunction::BERDecode(BufferedTransformation &bt) |
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{ |
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BERSequenceDecoder seq(bt); |
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m_n.BERDecode(seq); |
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m_r.BERDecode(seq); |
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m_s.BERDecode(seq); |
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m_p.BERDecode(seq); |
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m_q.BERDecode(seq); |
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m_u.BERDecode(seq); |
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seq.MessageEnd(); |
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} |
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void InvertibleRabinFunction::DEREncode(BufferedTransformation &bt) const |
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{ |
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DERSequenceEncoder seq(bt); |
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m_n.DEREncode(seq); |
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m_r.DEREncode(seq); |
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m_s.DEREncode(seq); |
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m_p.DEREncode(seq); |
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m_q.DEREncode(seq); |
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m_u.DEREncode(seq); |
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seq.MessageEnd(); |
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} |
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Integer InvertibleRabinFunction::CalculateInverse(RandomNumberGenerator &rng, const Integer &in) const |
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{ |
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DoQuickSanityCheck(); |
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ModularArithmetic modn(m_n); |
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Integer r(rng, Integer::One(), m_n - Integer::One()); |
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r = modn.Square(r); |
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Integer r2 = modn.Square(r); |
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Integer c = modn.Multiply(in, r2); // blind |
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Integer cp=c%m_p, cq=c%m_q; |
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int jp = Jacobi(cp, m_p); |
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int jq = Jacobi(cq, m_q); |
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if (jq==-1) |
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{ |
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cp = cp*EuclideanMultiplicativeInverse(m_r, m_p)%m_p; |
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cq = cq*EuclideanMultiplicativeInverse(m_r, m_q)%m_q; |
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} |
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if (jp==-1) |
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{ |
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cp = cp*EuclideanMultiplicativeInverse(m_s, m_p)%m_p; |
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cq = cq*EuclideanMultiplicativeInverse(m_s, m_q)%m_q; |
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} |
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cp = ModularSquareRoot(cp, m_p); |
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cq = ModularSquareRoot(cq, m_q); |
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if (jp==-1) |
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cp = m_p-cp; |
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Integer out = CRT(cq, m_q, cp, m_p, m_u); |
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out = modn.Divide(out, r); // unblind |
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if ((jq==-1 && out.IsEven()) || (jq==1 && out.IsOdd())) |
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out = m_n-out; |
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return out; |
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} |
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bool InvertibleRabinFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const |
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{ |
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bool pass = RabinFunction::Validate(rng, level); |
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pass = pass && m_p > Integer::One() && m_p%4 == 3 && m_p < m_n; |
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pass = pass && m_q > Integer::One() && m_q%4 == 3 && m_q < m_n; |
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pass = pass && m_u.IsPositive() && m_u < m_p; |
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if (level >= 1) |
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{ |
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pass = pass && m_p * m_q == m_n; |
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pass = pass && m_u * m_q % m_p == 1; |
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pass = pass && Jacobi(m_r, m_p) == 1; |
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pass = pass && Jacobi(m_r, m_q) == -1; |
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pass = pass && Jacobi(m_s, m_p) == -1; |
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pass = pass && Jacobi(m_s, m_q) == 1; |
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} |
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if (level >= 2) |
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pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2); |
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return pass; |
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} |
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bool InvertibleRabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const |
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{ |
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return GetValueHelper<RabinFunction>(this, name, valueType, pValue).Assignable() |
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CRYPTOPP_GET_FUNCTION_ENTRY(Prime1) |
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CRYPTOPP_GET_FUNCTION_ENTRY(Prime2) |
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CRYPTOPP_GET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) |
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; |
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} |
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void InvertibleRabinFunction::AssignFrom(const NameValuePairs &source) |
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{ |
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AssignFromHelper<RabinFunction>(this, source) |
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CRYPTOPP_SET_FUNCTION_ENTRY(Prime1) |
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CRYPTOPP_SET_FUNCTION_ENTRY(Prime2) |
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CRYPTOPP_SET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) |
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; |
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} |
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NAMESPACE_END
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