dh的C++加密算法代码.zip

// dh.cpp - written and placed in the public domain by Wei Dai #include "pch.h" #include "dh.h" #include "asn.h" #include "nbtheory.h" NAMESPACE_BEGIN(CryptoPP) DH::DH(const Integer &p, const Integer &g) : p(p), g(g), gpc(p, g, ExponentBitLength(), 1) { } DH::DH(RandomNumberGenerator &rng, unsigned int pbits) { PrimeAndGenerator pg(1, rng, pbits); p = pg.Prime(); g = pg.Generator(); gpc.Precompute(p, g, ExponentBitLength(), 1); } DH::DH(BufferedTransformation &bt) { BERSequenceDecoder seq(bt); p.BERDecode(seq); g.BERDecode(seq); gpc.Precompute(p, g, ExponentBitLength(), 1); } void DH::DEREncode(BufferedTransformation &bt) const { DERSequenceEncoder seq(bt); p.DEREncode(seq); g.DEREncode(seq); } void DH::Precompute(unsigned int precomputationStorage) { gpc.Precompute(p, g, ExponentBitLength(), precomputationStorage); } void DH::LoadPrecomputation(BufferedTransformation &bt) { gpc.Load(p, bt); } void DH::SavePrecomputation(BufferedTransformation &bt) const { gpc.Save(bt); } bool DH::ValidateDomainParameters(RandomNumberGenerator &rng) const { return VerifyPrime(rng, p) && VerifyPrime(rng, (p-1)/2) && g > 1 && g < p && Jacobi(g, p) == 1; } void DH::GenerateKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const { Integer x(rng, ExponentBitLength()); Integer y = gpc.Exponentiate(x); x.Encode(privateKey, PrivateKeyLength()); y.Encode(publicKey, PublicKeyLength()); } bool DH::Agree(byte *agreedValue, const byte *privateKey, const byte *otherPublicKey, bool validateOtherPublicKey) const { Integer w(otherPublicKey, PublicKeyLength()); if (validateOtherPublicKey && !(w > 1 && w < p && Jacobi(w, p) == 1)) return false; Integer s(privateKey, PrivateKeyLength()); Integer z = a_exp_b_mod_c(w, s, p); z.Encode(agreedValue, AgreedValueLength()); return true; } unsigned int DH::ExponentBitLength() const { return 2*DiscreteLogWorkFactor(p.BitCount()); } NAMESPACE_END