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