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Diffstat (limited to 'src/math/gfpmath/gfp_element.h')
| -rw-r--r-- | src/math/gfpmath/gfp_element.h | 249 |
1 files changed, 0 insertions, 249 deletions
diff --git a/src/math/gfpmath/gfp_element.h b/src/math/gfpmath/gfp_element.h deleted file mode 100644 index 17d4d9458..000000000 --- a/src/math/gfpmath/gfp_element.h +++ /dev/null @@ -1,249 +0,0 @@ -/* -* Arithmetic for prime fields GF(p) -* -* (C) 2007 Martin Doering, Christoph Ludwig, Falko Strenzke -* 2008-2010 Jack Lloyd -* -* Distributed under the terms of the Botan license -*/ - -#ifndef BOTAN_GFP_ELEMENT_H__ -#define BOTAN_GFP_ELEMENT_H__ - -#include <botan/bigint.h> -#include <botan/numthry.h> - -namespace Botan { - -/** - * This class represents one element in GF(p). Enables the convenient, - * transparent use of the montgomery multiplication. - */ -class BOTAN_DLL GFpElement - { - 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 *, *= - * @param p the prime number of the field - * @param value the element value - */ - GFpElement(const BigInt& p, const BigInt& value) : - mod_p(p), m_value(value % p) {} - - // GFpElement(const GFpElement& other) = default; - // const GFpElement& operator=(const GFpElement& other) = default; - - /** - * += Operator - * @param rhs the GFpElement to add to the local value - * @result *this - */ - GFpElement& operator+=(const GFpElement& rhs) - { - m_value += rhs.m_value; - if(m_value >= mod_p) - m_value -= mod_p; - - return *this; - } - - /** - * -= Operator - * @param rhs the GFpElement to subtract from the local value - * @result *this - */ - GFpElement& operator-=(const GFpElement& rhs) - { - m_value -= rhs.m_value; - if(m_value.is_negative()) - m_value += mod_p; - - return *this; - } - - /** - * *= Operator - * @param rhs the value to multiply with the local value - * @result *this - */ - GFpElement& operator*=(u32bit rhs) - { - m_value *= rhs; - m_value %= mod_p; - return *this; - } - - /** - * *= Operator - * @param rhs the GFpElement to multiply with the local value - * @result *this - */ - GFpElement& operator*=(const GFpElement& rhs) - { - m_value *= rhs.m_value; - m_value %= mod_p; - return *this; - } - - /** - * /= Operator - * @param rhs the GFpElement to divide the local value by - * @result *this - */ - GFpElement& operator/=(const GFpElement& rhs) - { - GFpElement inv_rhs(rhs); - inv_rhs.inverse_in_place(); - *this *= inv_rhs; - return *this; - } - - /** - * Negate internal value(*this *= -1 ) - * @return *this - */ - GFpElement& negate() - { - m_value = mod_p - m_value; - return *this; - } - - /** - * Assigns the inverse of *this to *this, i.e. - * *this = (*this)^(-1) - * @result *this - */ - GFpElement& inverse_in_place() - { - m_value = inverse_mod(m_value, mod_p); - return *this; - } - - /** - * checks whether the value is zero (without provoking - * a backtransformation to the ordinary-residue) - * @result true, if the value is zero, false otherwise. - */ - bool is_zero() const { return m_value.is_zero(); } - - /** - * return prime number of GF(p) - * @result a prime number - */ - const BigInt& get_p() const { return mod_p; } - - /** - * Return the represented value in GF(p) - * @result The value in GF(p) - */ - const BigInt& get_value() const { return m_value; } - - /** - * swaps the states of *this and other, does not throw! - * @param other The value to swap with - */ - void swap(GFpElement& other) - { - std::swap(m_value, other.m_value); - std::swap(mod_p, other.mod_p); - } - - bool operator==(const GFpElement& other) const - { - return (m_value == other.m_value && mod_p == other.mod_p); - } - - private: - BigInt mod_p; // modulus - BigInt m_value; - }; - -inline bool operator!=(const GFpElement& lhs, const GFpElement& rhs ) - { - return !(lhs == rhs); - } - -// arithmetic operators -inline GFpElement operator+(const GFpElement& lhs, const GFpElement& rhs) - { - GFpElement result(lhs); - result += rhs; - return result; - } - -inline GFpElement operator-(const GFpElement& lhs, const GFpElement& rhs) - { - GFpElement result(lhs); - result -= rhs; - return result; - } - -inline GFpElement operator-(const GFpElement& lhs) - { - return(GFpElement(lhs)).negate(); - } - -inline GFpElement operator*(const GFpElement& lhs, u32bit rhs) - { - GFpElement result(lhs); - result *= rhs; - return result; - } - -inline GFpElement operator*(const GFpElement& lhs, const GFpElement& rhs) - { - GFpElement result(lhs); - result *= rhs; - return result; - } - -inline GFpElement operator*(u32bit rhs, const GFpElement& lhs) - { - return rhs*lhs; - } - -inline GFpElement operator/(const GFpElement& lhs, const GFpElement& rhs) - { - GFpElement result (lhs); - result /= rhs; - return result; - } - -// return (*this)^(-1) -inline GFpElement inverse(const GFpElement& elem) - { - return GFpElement(elem).inverse_in_place(); - } - -// encoding and decoding -inline SecureVector<byte> FE2OSP(const GFpElement& elem) - { - return BigInt::encode_1363(elem.get_value(), elem.get_p().bytes()); - } - -inline GFpElement OS2FEP(const MemoryRegion<byte>& os, const BigInt& p) - { - return GFpElement(p, BigInt::decode(os.begin(), os.size())); - } - -inline void swap(GFpElement& x, GFpElement& y) - { - x.swap(y); - } - -} - -namespace std { - -template<> inline -void swap<Botan::GFpElement>(Botan::GFpElement& x, - Botan::GFpElement& y) - { - x.swap(y); - } - -} - -#endif |