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Diffstat (limited to '')
| -rw-r--r-- | CryptoPP/rabin.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/CryptoPP/rabin.cpp b/CryptoPP/rabin.cpp new file mode 100644 index 000000000..d496333b5 --- /dev/null +++ b/CryptoPP/rabin.cpp @@ -0,0 +1,221 @@ +// rabin.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" +#include "rabin.h" +#include "nbtheory.h" +#include "asn.h" +#include "sha.h" +#include "modarith.h" + +NAMESPACE_BEGIN(CryptoPP) + +void RabinFunction::BERDecode(BufferedTransformation &bt) +{ + BERSequenceDecoder seq(bt); + m_n.BERDecode(seq); + m_r.BERDecode(seq); + m_s.BERDecode(seq); + seq.MessageEnd(); +} + +void RabinFunction::DEREncode(BufferedTransformation &bt) const +{ + DERSequenceEncoder seq(bt); + m_n.DEREncode(seq); + m_r.DEREncode(seq); + m_s.DEREncode(seq); + seq.MessageEnd(); +} + +Integer RabinFunction::ApplyFunction(const Integer &in) const +{ + DoQuickSanityCheck(); + + Integer out = in.Squared()%m_n; + if (in.IsOdd()) + out = out*m_r%m_n; + if (Jacobi(in, m_n)==-1) + out = out*m_s%m_n; + return out; +} + +bool RabinFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const +{ + bool pass = true; + pass = pass && m_n > Integer::One() && m_n%4 == 1; + pass = pass && m_r > Integer::One() && m_r < m_n; + pass = pass && m_s > Integer::One() && m_s < m_n; + if (level >= 1) + pass = pass && Jacobi(m_r, m_n) == -1 && Jacobi(m_s, m_n) == -1; + return pass; +} + +bool RabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const +{ + return GetValueHelper(this, name, valueType, pValue).Assignable() + CRYPTOPP_GET_FUNCTION_ENTRY(Modulus) + CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime1) + CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime2) + ; +} + +void RabinFunction::AssignFrom(const NameValuePairs &source) +{ + AssignFromHelper(this, source) + CRYPTOPP_SET_FUNCTION_ENTRY(Modulus) + CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime1) + CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime2) + ; +} + +// ***************************************************************************** +// private key operations: + +// generate a random private key +void InvertibleRabinFunction::GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg) +{ + int modulusSize = 2048; + alg.GetIntValue("ModulusSize", modulusSize) || alg.GetIntValue("KeySize", modulusSize); + + if (modulusSize < 16) + throw InvalidArgument("InvertibleRabinFunction: specified modulus size is too small"); + + // VC70 workaround: putting these after primeParam causes overlapped stack allocation + bool rFound=false, sFound=false; + Integer t=2; + + AlgorithmParameters primeParam = MakeParametersForTwoPrimesOfEqualSize(modulusSize) + ("EquivalentTo", 3)("Mod", 4); + m_p.GenerateRandom(rng, primeParam); + m_q.GenerateRandom(rng, primeParam); + + while (!(rFound && sFound)) + { + int jp = Jacobi(t, m_p); + int jq = Jacobi(t, m_q); + + if (!rFound && jp==1 && jq==-1) + { + m_r = t; + rFound = true; + } + + if (!sFound && jp==-1 && jq==1) + { + m_s = t; + sFound = true; + } + + ++t; + } + + m_n = m_p * m_q; + m_u = m_q.InverseMod(m_p); +} + +void InvertibleRabinFunction::BERDecode(BufferedTransformation &bt) +{ + BERSequenceDecoder seq(bt); + m_n.BERDecode(seq); + m_r.BERDecode(seq); + m_s.BERDecode(seq); + m_p.BERDecode(seq); + m_q.BERDecode(seq); + m_u.BERDecode(seq); + seq.MessageEnd(); +} + +void InvertibleRabinFunction::DEREncode(BufferedTransformation &bt) const +{ + DERSequenceEncoder seq(bt); + m_n.DEREncode(seq); + m_r.DEREncode(seq); + m_s.DEREncode(seq); + m_p.DEREncode(seq); + m_q.DEREncode(seq); + m_u.DEREncode(seq); + seq.MessageEnd(); +} + +Integer InvertibleRabinFunction::CalculateInverse(RandomNumberGenerator &rng, const Integer &in) const +{ + DoQuickSanityCheck(); + + ModularArithmetic modn(m_n); + Integer r(rng, Integer::One(), m_n - Integer::One()); + r = modn.Square(r); + Integer r2 = modn.Square(r); + Integer c = modn.Multiply(in, r2); // blind + + Integer cp=c%m_p, cq=c%m_q; + + int jp = Jacobi(cp, m_p); + int jq = Jacobi(cq, m_q); + + if (jq==-1) + { + cp = cp*EuclideanMultiplicativeInverse(m_r, m_p)%m_p; + cq = cq*EuclideanMultiplicativeInverse(m_r, m_q)%m_q; + } + + if (jp==-1) + { + cp = cp*EuclideanMultiplicativeInverse(m_s, m_p)%m_p; + cq = cq*EuclideanMultiplicativeInverse(m_s, m_q)%m_q; + } + + cp = ModularSquareRoot(cp, m_p); + cq = ModularSquareRoot(cq, m_q); + + if (jp==-1) + cp = m_p-cp; + + Integer out = CRT(cq, m_q, cp, m_p, m_u); + + out = modn.Divide(out, r); // unblind + + if ((jq==-1 && out.IsEven()) || (jq==1 && out.IsOdd())) + out = m_n-out; + + return out; +} + +bool InvertibleRabinFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const +{ + bool pass = RabinFunction::Validate(rng, level); + pass = pass && m_p > Integer::One() && m_p%4 == 3 && m_p < m_n; + pass = pass && m_q > Integer::One() && m_q%4 == 3 && m_q < m_n; + pass = pass && m_u.IsPositive() && m_u < m_p; + if (level >= 1) + { + pass = pass && m_p * m_q == m_n; + pass = pass && m_u * m_q % m_p == 1; + pass = pass && Jacobi(m_r, m_p) == 1; + pass = pass && Jacobi(m_r, m_q) == -1; + pass = pass && Jacobi(m_s, m_p) == -1; + pass = pass && Jacobi(m_s, m_q) == 1; + } + if (level >= 2) + pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2); + return pass; +} + +bool InvertibleRabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const +{ + return GetValueHelper<RabinFunction>(this, name, valueType, pValue).Assignable() + CRYPTOPP_GET_FUNCTION_ENTRY(Prime1) + CRYPTOPP_GET_FUNCTION_ENTRY(Prime2) + CRYPTOPP_GET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) + ; +} + +void InvertibleRabinFunction::AssignFrom(const NameValuePairs &source) +{ + AssignFromHelper<RabinFunction>(this, source) + CRYPTOPP_SET_FUNCTION_ENTRY(Prime1) + CRYPTOPP_SET_FUNCTION_ENTRY(Prime2) + CRYPTOPP_SET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) + ; +} + +NAMESPACE_END |