dh2.h

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// dh2.h - originally written and placed in the public domain by Wei Dai

/// \file dh2.h
/// \brief Classes for Unified Diffie-Hellman key exchange
/// \since Crypto++ 3.0

#ifndef CRYPTOPP_DH2_H
#define CRYPTOPP_DH2_H

#include "cryptlib.h"

NAMESPACE_BEGIN(CryptoPP)

/// \brief Unified Diffie-Hellman in GF(p)
/// \details A Diffie-Hellman domain is a set of parameters that must be shared
///   by two parties in a key agreement protocol, along with the algorithms
///   for generating key pairs and deriving agreed values.
/// \sa AuthenticatedKeyAgreementDomain, <a href="http://www.weidai.com/scan-mirror/ka.html#DH2">Unified Diffie-Hellman</a>
/// \since Crypto++ 3.0
class DH2 : public AuthenticatedKeyAgreementDomain
{
public:
    virtual ~DH2() {}

    /// \brief Construct a DH2
    DH2(SimpleKeyAgreementDomain &domain)
        : d1(domain), d2(domain) {}
    /// \brief Construct a DH2
    DH2(SimpleKeyAgreementDomain &staticDomain, SimpleKeyAgreementDomain &ephemeralDomain)
        : d1(staticDomain), d2(ephemeralDomain) {}

    CryptoParameters & AccessCryptoParameters() {return d1.AccessCryptoParameters();}

    unsigned int AgreedValueLength() const
        {return d1.AgreedValueLength() + d2.AgreedValueLength();}

    unsigned int StaticPrivateKeyLength() const
        {return d1.PrivateKeyLength();}
    unsigned int StaticPublicKeyLength() const
        {return d1.PublicKeyLength();}
    void GenerateStaticPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const
        {d1.GeneratePrivateKey(rng, privateKey);}
    void GenerateStaticPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const
        {d1.GeneratePublicKey(rng, privateKey, publicKey);}
    void GenerateStaticKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const
        {d1.GenerateKeyPair(rng, privateKey, publicKey);}

    unsigned int EphemeralPrivateKeyLength() const
        {return d2.PrivateKeyLength();}
    unsigned int EphemeralPublicKeyLength() const
        {return d2.PublicKeyLength();}
    void GenerateEphemeralPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const
        {d2.GeneratePrivateKey(rng, privateKey);}
    void GenerateEphemeralPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const
        {d2.GeneratePublicKey(rng, privateKey, publicKey);}
    void GenerateEphemeralKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const
        {d2.GenerateKeyPair(rng, privateKey, publicKey);}

    bool Agree(byte *agreedValue,
        const byte *staticPrivateKey, const byte *ephemeralPrivateKey,
        const byte *staticOtherPublicKey, const byte *ephemeralOtherPublicKey,
        bool validateStaticOtherPublicKey=true) const;

protected:
    SimpleKeyAgreementDomain &d1, &d2;
};

NAMESPACE_END

#endif