diff options
Diffstat (limited to 'src/math/gfpmath/gfp_element.h')
| -rw-r--r-- | src/math/gfpmath/gfp_element.h | 122 |
1 files changed, 59 insertions, 63 deletions
diff --git a/src/math/gfpmath/gfp_element.h b/src/math/gfpmath/gfp_element.h index e9850df30..d576363ac 100644 --- a/src/math/gfpmath/gfp_element.h +++ b/src/math/gfpmath/gfp_element.h @@ -1,41 +1,42 @@ /****************************************************** * Arithmetic for prime fields GF(p) (header file) * * * - * (C) 2007 Martin Döring * -* [email protected] * -* Christoph Ludwig * -* [email protected] * -* Falko Strenzke * -* [email protected] * -******************************************************/ + * (C) 2007 Martin Doering * + * [email protected] * + * Christoph Ludwig * + * [email protected] * + * Falko Strenzke * + * [email protected] * + ******************************************************/ -#ifndef BOTAN_MATH_GF_GFP_ELEMENT_H_GUARD_ -#define BOTAN_MATH_GF_GFP_ELEMENT_H_GUARD_ +#ifndef BOTAN_GFP_ELEMENT_H__ +#define BOTAN_GFP_ELEMENT_H__ -#include <botan/gfp_modulus.h> #include <botan/bigint.h> -#include <tr1/memory> +#include <botan/gfp_modulus.h> +#include <botan/freestore.h> +#include <iostream> -namespace Botan -{ +namespace Botan { struct Illegal_Transformation : public Exception -{ - Illegal_Transformation(const std::string& err = "Requested transformation is not possible") - : Exception(err) {} -}; + { + Illegal_Transformation(const std::string& err = + "Requested transformation is not possible") + : Exception(err) {} + }; /** -* This class represents one element in GF(p). Enables the convenient, transparent use -* of the montgomery multiplication. -*/ + * This class represents one element in GF(p). Enables the convenient, transparent use + * of the montgomery multiplication. + */ class GFpElement { - private: std::tr1::shared_ptr<GFpModulus> mp_mod; mutable BigInt m_value; // ordinary residue or m-residue respectively mutable BigInt workspace; + // ***************************************** // data members for montgomery multiplication mutable bool m_use_montgm; @@ -44,22 +45,20 @@ class GFpElement // the actual value (in this case mValue doesn´t) mutable bool m_is_trf; - void ensure_montgm_precomp() const; void trf_to_mres() const; void trf_to_ordres() const; public: - /** construct an element of GF(p) with the given value. - * use_montg defaults to false and determines wether Montgomery multiplications - * will be use when applying operators '*' , '*='. + * use_montg defaults to false and determines wether Montgomery + * multiplications will be use when applying operators *, *= * @param p the prime number of the field * @param value the element value * @param use_montgm whether this object will use Montgomery multiplication */ - explicit GFpElement ( const BigInt& p, const BigInt& value, bool use_montgm = false ); + explicit GFpElement (const BigInt& p, const BigInt& value, bool use_montgm = false ); /** construct an element of GF(p) with the given value (defaults to 0). @@ -80,7 +79,7 @@ class GFpElement * Copy constructor * @param other The element to clone */ - GFpElement ( GFpElement const& other ); + GFpElement ( const GFpElement& other ); /** * Assignment operator. @@ -89,7 +88,7 @@ class GFpElement * * @param other The element to assign to our object */ - GFpElement const& operator= ( GFpElement const& other ); + const GFpElement& operator= ( const GFpElement& other ); /** * Works like the assignment operator, but lets @@ -99,7 +98,7 @@ class GFpElement * the shared GFpModulus objects! * @param other The element to assign to our object */ - void share_assign(GFpElement const& other); + void share_assign(const GFpElement& other); /** * Switch Montgomery multiplcation optimizations ON @@ -116,27 +115,27 @@ class GFpElement * @param rhs the GFpElement to add to the local value * @result *this */ - GFpElement& operator+= ( GFpElement const& rhs ); + GFpElement& operator+= ( const GFpElement& rhs ); /** * -= Operator * @param rhs the GFpElement to subtract from the local value * @result *this */ - GFpElement& operator-= ( GFpElement const& rhs ); + GFpElement& operator-= ( const GFpElement& rhs ); /** * *= Operator * @param rhs the GFpElement to multiply with the local value * @result *this */ - GFpElement& operator*= ( GFpElement const& rhs ); + GFpElement& operator*= ( const GFpElement& rhs ); /** * /= Operator * @param rhs the GFpElement to divide the local value by * @result *this */ - GFpElement& operator/= ( GFpElement const& rhs ); + GFpElement& operator/= ( const GFpElement& rhs ); /** * *= Operator @@ -235,7 +234,7 @@ class GFpElement * @result true if both are transformed to their m-residue, * false it both are transformed to their normal residue. */ - static bool align_operands_res(GFpElement const& lhs, GFpElement const& rhs); + static bool align_operands_res(const GFpElement& lhs, const GFpElement& rhs); //friend declarations for non-member functions @@ -245,6 +244,8 @@ class GFpElement * @param elem the object to write * @result the output stream */ + friend std::ostream& operator<< ( std::ostream& output, const GFpElement& elem ); + friend class Point_Coords_GFp; /** @@ -256,53 +257,48 @@ class GFpElement }; // relational operators -bool operator== ( GFpElement const& lhs, GFpElement const& rhs ); -inline bool operator!= ( GFpElement const& lhs, GFpElement const& rhs ) +bool operator== ( const GFpElement& lhs, const GFpElement& rhs ); +inline bool operator!= ( const GFpElement& lhs, const GFpElement& rhs ) { return !operator== ( lhs, rhs ); } // arithmetic operators -GFpElement operator+ ( GFpElement const& lhs, GFpElement const& rhs ); -GFpElement operator- ( GFpElement const& lhs, GFpElement const& rhs ); -GFpElement operator- ( GFpElement const& lhs ); +GFpElement operator+ ( const GFpElement& lhs, const GFpElement& rhs ); +GFpElement operator- ( const GFpElement& lhs, const GFpElement& rhs ); +GFpElement operator- ( const GFpElement& lhs ); + +GFpElement operator* ( const GFpElement& lhs, const GFpElement& rhs ); +GFpElement operator/ ( const GFpElement& lhs, const GFpElement& rhs ); +GFpElement operator* (const GFpElement& lhs, u32bit rhs); +GFpElement operator* (u32bit rhs, const GFpElement& lhs); -GFpElement operator* ( GFpElement const& lhs, GFpElement const& rhs ); -GFpElement operator/ ( GFpElement const& lhs, GFpElement const& rhs ); -GFpElement operator* (GFpElement const& lhs, u32bit rhs); -GFpElement operator* (u32bit rhs, GFpElement const& lhs); +// io operators +std::ostream& operator<< ( std::ostream& output, const GFpElement& elem ); // return (*this)^(-1) -GFpElement inverse ( GFpElement const& elem ); +GFpElement inverse ( const GFpElement& elem ); // encoding and decoding -SecureVector<byte> FE2OSP ( GFpElement const& elem ); -GFpElement OS2FEP ( MemoryRegion<byte> const& os, BigInt p ); - +SecureVector<byte> FE2OSP ( const GFpElement& elem ); +GFpElement OS2FEP ( MemoryRegion<byte> const& os, BigInt p); -// swaps the states of elem1 and elem2, does not throw! -// cf. Meyers, Item 25 -inline -void swap ( GFpElement& elem1, GFpElement& elem2 ) +inline void swap(GFpElement& x, GFpElement& y) { - elem1.swap ( elem2 ); + x.swap(y); } -} // namespace Botan +} -namespace std -{ +namespace std { -// swaps the states of elem1 and elem2, does not throw! -// cf. Meyers, Item 25 -template<> -inline -void swap< Botan::GFpElement>(Botan::GFpElement& elem1, - Botan::GFpElement& elem2) +template<> inline +void swap<Botan::GFpElement>(Botan::GFpElement& x, + Botan::GFpElement& y) { - elem1.swap(elem2); + x.swap(y); } -} // namespace std +} #endif |