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Diffstat (limited to '')
| -rw-r--r-- | CryptoPP/mqv.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/CryptoPP/mqv.h b/CryptoPP/mqv.h new file mode 100644 index 000000000..2683817b0 --- /dev/null +++ b/CryptoPP/mqv.h @@ -0,0 +1,141 @@ +#ifndef CRYPTOPP_MQV_H +#define CRYPTOPP_MQV_H + +/** \file +*/ + +#include "gfpcrypt.h" + +NAMESPACE_BEGIN(CryptoPP) + +//! _ +template <class GROUP_PARAMETERS, class COFACTOR_OPTION = CPP_TYPENAME GROUP_PARAMETERS::DefaultCofactorOption> +class MQV_Domain : public AuthenticatedKeyAgreementDomain +{ +public: + typedef GROUP_PARAMETERS GroupParameters; + typedef typename GroupParameters::Element Element; + typedef MQV_Domain<GROUP_PARAMETERS, COFACTOR_OPTION> Domain; + + MQV_Domain() {} + + MQV_Domain(const GroupParameters ¶ms) + : m_groupParameters(params) {} + + MQV_Domain(BufferedTransformation &bt) + {m_groupParameters.BERDecode(bt);} + + template <class T1, class T2> + MQV_Domain(T1 v1, T2 v2) + {m_groupParameters.Initialize(v1, v2);} + + template <class T1, class T2, class T3> + MQV_Domain(T1 v1, T2 v2, T3 v3) + {m_groupParameters.Initialize(v1, v2, v3);} + + template <class T1, class T2, class T3, class T4> + MQV_Domain(T1 v1, T2 v2, T3 v3, T4 v4) + {m_groupParameters.Initialize(v1, v2, v3, v4);} + + const GroupParameters & GetGroupParameters() const {return m_groupParameters;} + GroupParameters & AccessGroupParameters() {return m_groupParameters;} + + CryptoParameters & AccessCryptoParameters() {return AccessAbstractGroupParameters();} + + unsigned int AgreedValueLength() const {return GetAbstractGroupParameters().GetEncodedElementSize(false);} + unsigned int StaticPrivateKeyLength() const {return GetAbstractGroupParameters().GetSubgroupOrder().ByteCount();} + unsigned int StaticPublicKeyLength() const {return GetAbstractGroupParameters().GetEncodedElementSize(true);} + + void GenerateStaticPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const + { + Integer x(rng, Integer::One(), GetAbstractGroupParameters().GetMaxExponent()); + x.Encode(privateKey, StaticPrivateKeyLength()); + } + + void GenerateStaticPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const + { + const DL_GroupParameters<Element> ¶ms = GetAbstractGroupParameters(); + Integer x(privateKey, StaticPrivateKeyLength()); + Element y = params.ExponentiateBase(x); + params.EncodeElement(true, y, publicKey); + } + + unsigned int EphemeralPrivateKeyLength() const {return StaticPrivateKeyLength() + StaticPublicKeyLength();} + unsigned int EphemeralPublicKeyLength() const {return StaticPublicKeyLength();} + + void GenerateEphemeralPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const + { + const DL_GroupParameters<Element> ¶ms = GetAbstractGroupParameters(); + Integer x(rng, Integer::One(), params.GetMaxExponent()); + x.Encode(privateKey, StaticPrivateKeyLength()); + Element y = params.ExponentiateBase(x); + params.EncodeElement(true, y, privateKey+StaticPrivateKeyLength()); + } + + void GenerateEphemeralPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const + { + memcpy(publicKey, privateKey+StaticPrivateKeyLength(), EphemeralPublicKeyLength()); + } + + bool Agree(byte *agreedValue, + const byte *staticPrivateKey, const byte *ephemeralPrivateKey, + const byte *staticOtherPublicKey, const byte *ephemeralOtherPublicKey, + bool validateStaticOtherPublicKey=true) const + { + try + { + const DL_GroupParameters<Element> ¶ms = GetAbstractGroupParameters(); + Element WW = params.DecodeElement(staticOtherPublicKey, validateStaticOtherPublicKey); + Element VV = params.DecodeElement(ephemeralOtherPublicKey, true); + + Integer s(staticPrivateKey, StaticPrivateKeyLength()); + Integer u(ephemeralPrivateKey, StaticPrivateKeyLength()); + Element V = params.DecodeElement(ephemeralPrivateKey+StaticPrivateKeyLength(), false); + + const Integer &r = params.GetSubgroupOrder(); + Integer h2 = Integer::Power2((r.BitCount()+1)/2); + Integer e = ((h2+params.ConvertElementToInteger(V)%h2)*s+u) % r; + Integer tt = h2 + params.ConvertElementToInteger(VV) % h2; + + if (COFACTOR_OPTION::ToEnum() == NO_COFACTOR_MULTIPLICTION) + { + Element P = params.ExponentiateElement(WW, tt); + P = m_groupParameters.MultiplyElements(P, VV); + Element R[2]; + const Integer e2[2] = {r, e}; + params.SimultaneousExponentiate(R, P, e2, 2); + if (!params.IsIdentity(R[0]) || params.IsIdentity(R[1])) + return false; + params.EncodeElement(false, R[1], agreedValue); + } + else + { + const Integer &k = params.GetCofactor(); + if (COFACTOR_OPTION::ToEnum() == COMPATIBLE_COFACTOR_MULTIPLICTION) + e = ModularArithmetic(r).Divide(e, k); + Element P = m_groupParameters.CascadeExponentiate(VV, k*e, WW, k*(e*tt%r)); + if (params.IsIdentity(P)) + return false; + params.EncodeElement(false, P, agreedValue); + } + } + catch (DL_BadElement &) + { + return false; + } + return true; + } + +private: + DL_GroupParameters<Element> & AccessAbstractGroupParameters() {return m_groupParameters;} + const DL_GroupParameters<Element> & GetAbstractGroupParameters() const {return m_groupParameters;} + + GroupParameters m_groupParameters; +}; + +//! Menezes-Qu-Vanstone in GF(p) with key validation, AKA <a href="http://www.weidai.com/scan-mirror/ka.html#MQV">MQV</a> +typedef MQV_Domain<DL_GroupParameters_GFP_DefaultSafePrime> MQV; + +NAMESPACE_END + +#endif |