123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121 |
- // Copyright 2020 The go-ethereum Authors
- // This file is part of the go-ethereum library.
- //
- // The go-ethereum library is free software: you can redistribute it and/or modify
- // it under the terms of the GNU Lesser General Public License as published by
- // the Free Software Foundation, either version 3 of the License, or
- // (at your option) any later version.
- //
- // The go-ethereum library is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU Lesser General Public License for more details.
- //
- // You should have received a copy of the GNU Lesser General Public License
- // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
- package bls12381
- import (
- "errors"
- "math/big"
- )
- // E is type for target group element
- type E = fe12
- // GT is type for target multiplicative group GT.
- type GT struct {
- fp12 *fp12
- }
- func (e *E) Set(e2 *E) *E {
- return e.set(e2)
- }
- // One sets a new target group element to one
- func (e *E) One() *E {
- e = new(fe12).one()
- return e
- }
- // IsOne returns true if given element equals to one
- func (e *E) IsOne() bool {
- return e.isOne()
- }
- // Equal returns true if given two element is equal, otherwise returns false
- func (g *E) Equal(g2 *E) bool {
- return g.equal(g2)
- }
- // NewGT constructs new target group instance.
- func NewGT() *GT {
- fp12 := newFp12(nil)
- return >{fp12}
- }
- // Q returns group order in big.Int.
- func (g *GT) Q() *big.Int {
- return new(big.Int).Set(q)
- }
- // FromBytes expects 576 byte input and returns target group element
- // FromBytes returns error if given element is not on correct subgroup.
- func (g *GT) FromBytes(in []byte) (*E, error) {
- e, err := g.fp12.fromBytes(in)
- if err != nil {
- return nil, err
- }
- if !g.IsValid(e) {
- return e, errors.New("invalid element")
- }
- return e, nil
- }
- // ToBytes serializes target group element.
- func (g *GT) ToBytes(e *E) []byte {
- return g.fp12.toBytes(e)
- }
- // IsValid checks whether given target group element is in correct subgroup.
- func (g *GT) IsValid(e *E) bool {
- r := g.New()
- g.fp12.exp(r, e, q)
- return r.isOne()
- }
- // New initializes a new target group element which is equal to one
- func (g *GT) New() *E {
- return new(E).One()
- }
- // Add adds two field element `a` and `b` and assigns the result to the element in first argument.
- func (g *GT) Add(c, a, b *E) {
- g.fp12.add(c, a, b)
- }
- // Sub subtracts two field element `a` and `b`, and assigns the result to the element in first argument.
- func (g *GT) Sub(c, a, b *E) {
- g.fp12.sub(c, a, b)
- }
- // Mul multiplies two field element `a` and `b` and assigns the result to the element in first argument.
- func (g *GT) Mul(c, a, b *E) {
- g.fp12.mul(c, a, b)
- }
- // Square squares an element `a` and assigns the result to the element in first argument.
- func (g *GT) Square(c, a *E) {
- g.fp12.cyclotomicSquare(c, a)
- }
- // Exp exponents an element `a` by a scalar `s` and assigns the result to the element in first argument.
- func (g *GT) Exp(c, a *E, s *big.Int) {
- g.fp12.cyclotomicExp(c, a, s)
- }
- // Inverse inverses an element `a` and assigns the result to the element in first argument.
- func (g *GT) Inverse(c, a *E) {
- g.fp12.inverse(c, a)
- }
|