/************************************************* * Modular Exponentiator Header File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #ifndef BOTAN_POWER_MOD_H__ #define BOTAN_POWER_MOD_H__ #include namespace Botan { /************************************************* * Modular Exponentiator Interface * *************************************************/ class BOTAN_DLL Modular_Exponentiator { public: virtual void set_base(const BigInt&) = 0; virtual void set_exponent(const BigInt&) = 0; virtual BigInt execute() const = 0; virtual Modular_Exponentiator* copy() const = 0; virtual ~Modular_Exponentiator() {} }; /************************************************* * Modular Exponentiator Proxy * *************************************************/ class BOTAN_DLL Power_Mod { public: enum Usage_Hints { NO_HINTS = 0x0000, BASE_IS_FIXED = 0x0001, BASE_IS_SMALL = 0x0002, BASE_IS_LARGE = 0x0004, BASE_IS_2 = 0x0008, EXP_IS_FIXED = 0x0100, EXP_IS_SMALL = 0x0200, EXP_IS_LARGE = 0x0400 }; void set_modulus(const BigInt&, Usage_Hints = NO_HINTS) const; void set_base(const BigInt&) const; void set_exponent(const BigInt&) const; BigInt execute() const; Power_Mod& operator=(const Power_Mod&); Power_Mod(const BigInt& = 0, Usage_Hints = NO_HINTS); Power_Mod(const Power_Mod&); ~Power_Mod(); private: mutable Modular_Exponentiator* core; Usage_Hints hints; }; /************************************************* * Fixed Exponent Modular Exponentiator Proxy * *************************************************/ class BOTAN_DLL Fixed_Exponent_Power_Mod : public Power_Mod { public: BigInt operator()(const BigInt& b) const { set_base(b); return execute(); } Fixed_Exponent_Power_Mod() {} Fixed_Exponent_Power_Mod(const BigInt&, const BigInt&, Usage_Hints = NO_HINTS); }; /************************************************* * Fixed Base Modular Exponentiator Proxy * *************************************************/ class BOTAN_DLL Fixed_Base_Power_Mod : public Power_Mod { public: BigInt operator()(const BigInt& e) const { set_exponent(e); return execute(); } Fixed_Base_Power_Mod() {} Fixed_Base_Power_Mod(const BigInt&, const BigInt&, Usage_Hints = NO_HINTS); }; } #endif