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Diffstat (limited to '')
| -rw-r--r-- | CryptoPP/rw.cpp | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/CryptoPP/rw.cpp b/CryptoPP/rw.cpp new file mode 100644 index 000000000..cdd9f2d22 --- /dev/null +++ b/CryptoPP/rw.cpp @@ -0,0 +1,196 @@ +// rw.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" +#include "rw.h" +#include "nbtheory.h" +#include "asn.h" + +#ifndef CRYPTOPP_IMPORTS + +NAMESPACE_BEGIN(CryptoPP) + +void RWFunction::BERDecode(BufferedTransformation &bt) +{ + BERSequenceDecoder seq(bt); + m_n.BERDecode(seq); + seq.MessageEnd(); +} + +void RWFunction::DEREncode(BufferedTransformation &bt) const +{ + DERSequenceEncoder seq(bt); + m_n.DEREncode(seq); + seq.MessageEnd(); +} + +Integer RWFunction::ApplyFunction(const Integer &in) const +{ + DoQuickSanityCheck(); + + Integer out = in.Squared()%m_n; + const word r = 12; + // this code was written to handle both r = 6 and r = 12, + // but now only r = 12 is used in P1363 + const word r2 = r/2; + const word r3a = (16 + 5 - r) % 16; // n%16 could be 5 or 13 + const word r3b = (16 + 13 - r) % 16; + const word r4 = (8 + 5 - r/2) % 8; // n%8 == 5 + switch (out % 16) + { + case r: + break; + case r2: + case r2+8: + out <<= 1; + break; + case r3a: + case r3b: + out.Negate(); + out += m_n; + break; + case r4: + case r4+8: + out.Negate(); + out += m_n; + out <<= 1; + break; + default: + out = Integer::Zero(); + } + return out; +} + +bool RWFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const +{ + bool pass = true; + pass = pass && m_n > Integer::One() && m_n%8 == 5; + return pass; +} + +bool RWFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const +{ + return GetValueHelper(this, name, valueType, pValue).Assignable() + CRYPTOPP_GET_FUNCTION_ENTRY(Modulus) + ; +} + +void RWFunction::AssignFrom(const NameValuePairs &source) +{ + AssignFromHelper(this, source) + CRYPTOPP_SET_FUNCTION_ENTRY(Modulus) + ; +} + +// ***************************************************************************** +// private key operations: + +// generate a random private key +void InvertibleRWFunction::GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg) +{ + int modulusSize = 2048; + alg.GetIntValue("ModulusSize", modulusSize) || alg.GetIntValue("KeySize", modulusSize); + + if (modulusSize < 16) + throw InvalidArgument("InvertibleRWFunction: specified modulus length is too small"); + + AlgorithmParameters primeParam = MakeParametersForTwoPrimesOfEqualSize(modulusSize); + m_p.GenerateRandom(rng, CombinedNameValuePairs(primeParam, MakeParameters("EquivalentTo", 3)("Mod", 8))); + m_q.GenerateRandom(rng, CombinedNameValuePairs(primeParam, MakeParameters("EquivalentTo", 7)("Mod", 8))); + + m_n = m_p * m_q; + m_u = m_q.InverseMod(m_p); +} + +void InvertibleRWFunction::BERDecode(BufferedTransformation &bt) +{ + BERSequenceDecoder seq(bt); + m_n.BERDecode(seq); + m_p.BERDecode(seq); + m_q.BERDecode(seq); + m_u.BERDecode(seq); + seq.MessageEnd(); +} + +void InvertibleRWFunction::DEREncode(BufferedTransformation &bt) const +{ + DERSequenceEncoder seq(bt); + m_n.DEREncode(seq); + m_p.DEREncode(seq); + m_q.DEREncode(seq); + m_u.DEREncode(seq); + seq.MessageEnd(); +} + +Integer InvertibleRWFunction::CalculateInverse(RandomNumberGenerator &rng, const Integer &x) const +{ + DoQuickSanityCheck(); + ModularArithmetic modn(m_n); + Integer r, rInv; + do { // do this in a loop for people using small numbers for testing + r.Randomize(rng, Integer::One(), m_n - Integer::One()); + rInv = modn.MultiplicativeInverse(r); + } while (rInv.IsZero()); + Integer re = modn.Square(r); + re = modn.Multiply(re, x); // blind + + Integer cp=re%m_p, cq=re%m_q; + if (Jacobi(cp, m_p) * Jacobi(cq, m_q) != 1) + { + cp = cp.IsOdd() ? (cp+m_p) >> 1 : cp >> 1; + cq = cq.IsOdd() ? (cq+m_q) >> 1 : cq >> 1; + } + + #pragma omp parallel + #pragma omp sections + { + #pragma omp section + cp = ModularSquareRoot(cp, m_p); + #pragma omp section + cq = ModularSquareRoot(cq, m_q); + } + + Integer y = CRT(cq, m_q, cp, m_p, m_u); + y = modn.Multiply(y, rInv); // unblind + y = STDMIN(y, m_n-y); + if (ApplyFunction(y) != x) // check + throw Exception(Exception::OTHER_ERROR, "InvertibleRWFunction: computational error during private key operation"); + return y; +} + +bool InvertibleRWFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const +{ + bool pass = RWFunction::Validate(rng, level); + pass = pass && m_p > Integer::One() && m_p%8 == 3 && m_p < m_n; + pass = pass && m_q > Integer::One() && m_q%8 == 7 && 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; + } + if (level >= 2) + pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2); + return pass; +} + +bool InvertibleRWFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const +{ + return GetValueHelper<RWFunction>(this, name, valueType, pValue).Assignable() + CRYPTOPP_GET_FUNCTION_ENTRY(Prime1) + CRYPTOPP_GET_FUNCTION_ENTRY(Prime2) + CRYPTOPP_GET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) + ; +} + +void InvertibleRWFunction::AssignFrom(const NameValuePairs &source) +{ + AssignFromHelper<RWFunction>(this, source) + CRYPTOPP_SET_FUNCTION_ENTRY(Prime1) + CRYPTOPP_SET_FUNCTION_ENTRY(Prime2) + CRYPTOPP_SET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1) + ; +} + +NAMESPACE_END + +#endif |