bn128_g2.hpp

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#ifndef BN128_G2_HPP_
#define BN128_G2_HPP_
#include "depends/ate-pairing/include/bn.h"
 
#include <iostream>
#include <libff/algebra/curves/bn128/bn128_init.hpp>
#include <libff/algebra/curves/curve_utils.hpp>
#include <vector>
 
namespace libff
{
 
class bn128_G2;
std::ostream &operator<<(std::ostream &, const bn128_G2 &);
std::istream &operator>>(std::istream &, bn128_G2 &);
 
class bn128_G2
{
private:
    static bn::Fp2 sqrt(const bn::Fp2 &el);
 
public:
#ifdef PROFILE_OP_COUNTS
    static long long add_cnt;
    static long long dbl_cnt;
#endif
    static std::vector<size_t> wnaf_window_table;
    static std::vector<size_t> fixed_base_exp_window_table;
    static bn128_G2 G2_zero;
    static bn128_G2 G2_one;
 
    typedef bn128_Fq base_field;
    typedef bn128_Fr scalar_field;
 
    // Cofactor
    static const mp_size_t h_bitcount = 256;
    static const mp_size_t h_limbs =
        (h_bitcount + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS;
    static bigint<h_limbs> h;
 
    bn::Fp2 X, Y, Z;
    void fill_coord(bn::Fp2 coord[3]) const
    {
        coord[0] = this->X;
        coord[1] = this->Y;
        coord[2] = this->Z;
    };
 
    bn128_G2();
    bn128_G2(bn::Fp2 coord[3]) : X(coord[0]), Y(coord[1]), Z(coord[2]){};
 
    void print() const;
    void print_coordinates() const;
 
    void to_affine_coordinates();
    void to_special();
    bool is_special() const;
 
    bool is_zero() const;
 
    bool operator==(const bn128_G2 &other) const;
    bool operator!=(const bn128_G2 &other) const;
 
    bn128_G2 operator+(const bn128_G2 &other) const;
    bn128_G2 operator-() const;
    bn128_G2 operator-(const bn128_G2 &other) const;
 
    bn128_G2 add(const bn128_G2 &other) const;
    bn128_G2 mixed_add(const bn128_G2 &other) const;
    bn128_G2 dbl() const;
    bn128_G2 mul_by_cofactor() const;
 
    bool is_well_formed() const;
    bool is_in_safe_subgroup() const;
 
    static const bn128_G2 &zero();
    static const bn128_G2 &one();
    static bn128_G2 random_element();
 
    static size_t size_in_bits() { return 2 * base_field::size_in_bits() + 1; }
    static bigint<base_field::num_limbs> base_field_char()
    {
        return base_field::field_char();
    }
    static bigint<scalar_field::num_limbs> order()
    {
        return scalar_field::field_char();
    }
 
    void write_uncompressed(std::ostream &) const;
    void write_compressed(std::ostream &) const;
    static void read_uncompressed(std::istream &, bn128_G2 &);
    static void read_compressed(std::istream &, bn128_G2 &);
 
    static void batch_to_special_all_non_zeros(std::vector<bn128_G2> &vec);
};
 
template<mp_size_t m>
bn128_G2 operator*(const bigint<m> &lhs, const bn128_G2 &rhs)
{
    return scalar_mul<bn128_G2, m>(rhs, lhs);
}
 
template<mp_size_t m, const bigint<m> &modulus_p>
bn128_G2 operator*(const Fp_model<m, modulus_p> &lhs, const bn128_G2 &rhs)
{
    return scalar_mul<bn128_G2, m>(rhs, lhs.as_bigint());
}
 
} // namespace libff
#endif // BN128_G2_HPP_