rabin.h

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


#ifndef CRYPTOPP_RABIN_H
#define CRYPTOPP_RABIN_H

#include "cryptlib.h"
#include "oaep.h"
#include "pssr.h"
#include "integer.h"

NAMESPACE_BEGIN(CryptoPP)

class RabinFunction : public TrapdoorFunction, public PublicKey
{
        typedef RabinFunction ThisClass;

public:

        void Initialize(const Integer &n, const Integer &r, const Integer &s)
                {m_n = n; m_r = r; m_s = s;}

        void BERDecode(BufferedTransformation &bt);
        void DEREncode(BufferedTransformation &bt) const;

        Integer ApplyFunction(const Integer &x) const;
        Integer PreimageBound() const {return m_n;}
        Integer ImageBound() const {return m_n;}

        bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
        bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
        void AssignFrom(const NameValuePairs &source);

        const Integer& GetModulus() const {return m_n;}
        const Integer& GetQuadraticResidueModPrime1() const {return m_r;}
        const Integer& GetQuadraticResidueModPrime2() const {return m_s;}

        void SetModulus(const Integer &n) {m_n = n;}
        void SetQuadraticResidueModPrime1(const Integer &r) {m_r = r;}
        void SetQuadraticResidueModPrime2(const Integer &s) {m_s = s;}

protected:
        Integer m_n, m_r, m_s;
};

class InvertibleRabinFunction : public RabinFunction, public TrapdoorFunctionInverse, public PrivateKey
{
        typedef InvertibleRabinFunction ThisClass;

public:

        void Initialize(const Integer &n, const Integer &r, const Integer &s, const Integer &p, const Integer &q, const Integer &u)
                {m_n = n; m_r = r; m_s = s; m_p = p; m_q = q; m_u = u;}

        void Initialize(RandomNumberGenerator &rng, unsigned int keybits)
                {GenerateRandomWithKeySize(rng, keybits);}

        void BERDecode(BufferedTransformation &bt);
        void DEREncode(BufferedTransformation &bt) const;

        Integer CalculateInverse(RandomNumberGenerator &rng, const Integer &x) const;

        bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
        bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
        void AssignFrom(const NameValuePairs &source);
        void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);

        const Integer& GetPrime1() const {return m_p;}
        const Integer& GetPrime2() const {return m_q;}
        const Integer& GetMultiplicativeInverseOfPrime2ModPrime1() const {return m_u;}

        void SetPrime1(const Integer &p) {m_p = p;}
        void SetPrime2(const Integer &q) {m_q = q;}
        void SetMultiplicativeInverseOfPrime2ModPrime1(const Integer &u) {m_u = u;}

protected:
        Integer m_p, m_q, m_u;
};

struct Rabin
{
        static std::string StaticAlgorithmName() {return "Rabin-Crypto++Variant";}
        typedef RabinFunction PublicKey;
        typedef InvertibleRabinFunction PrivateKey;
};

template <class STANDARD>
struct RabinES : public TF_ES<Rabin, STANDARD>
{
};

template <class STANDARD, class H>
struct RabinSS : public TF_SS<Rabin, STANDARD, H>
{
};

// More typedefs for backwards compatibility
class SHA1;
typedef RabinES<OAEP<SHA1> >::Decryptor RabinDecryptor;
typedef RabinES<OAEP<SHA1> >::Encryptor RabinEncryptor;

NAMESPACE_END

#endif