github.com/bigzoro/my_simplechain@v0.0.0-20240315012955-8ad0a2a29bb9/consensus/hotstuff/bls12-381/primitive.go (about)

     1  package bls
     2  
     3  import (
     4  	"math/big"
     5  
     6  	bls12381 "github.com/kilic/bls12-381"
     7  )
     8  
     9  var (
    10  	domain = []byte("BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_")
    11  
    12  	// the order r of G1
    13  	curveOrder, _ = new(big.Int).SetString("73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001", 16)
    14  )
    15  
    16  func subgroupCheck(point *bls12381.PointG2) bool {
    17  	g2, p := bls12381.NewG2(), new(bls12381.PointG2)
    18  	g2.MulScalarBig(p, point, curveOrder)
    19  	return g2.IsZero(p)
    20  }
    21  
    22  func sign(sec *big.Int, msg []byte) (*bls12381.PointG2, error) {
    23  	g2 := bls12381.NewG2()
    24  	point, err := g2.HashToCurve(msg, domain)
    25  	if err != nil {
    26  		return nil, err
    27  	}
    28  	g2.MulScalarBig(point, point, sec)
    29  	return point, nil
    30  }
    31  
    32  func verify(pub *bls12381.PointG1, msg []byte, sig *bls12381.PointG2) bool {
    33  	if !subgroupCheck(sig) {
    34  		return false
    35  	}
    36  	g2 := bls12381.NewG2()
    37  	point, err := g2.HashToCurve(msg, domain)
    38  	if err != nil {
    39  		return false
    40  	}
    41  	engine := bls12381.NewEngine()
    42  	engine.AddPairInv(&bls12381.G1One, sig)
    43  	engine.AddPair(pub, point)
    44  	return engine.Result().IsOne()
    45  }
    46  
    47  func fastAggregateVerify(msg []byte, sig *bls12381.PointG2, pubs ...*bls12381.PointG1) bool {
    48  	engine, aggregate := bls12381.NewEngine(), new(bls12381.PointG1)
    49  	for _, pub := range pubs {
    50  		engine.G1.Add(aggregate, aggregate, pub)
    51  	}
    52  	return verify(aggregate, msg, sig)
    53  }
    54  
    55  func combine(sigs ...*bls12381.PointG2) *bls12381.PointG2 {
    56  	g2, aggregate := bls12381.NewG2(), new(bls12381.PointG2)
    57  	for _, sig := range sigs {
    58  		g2.Add(aggregate, aggregate, sig)
    59  	}
    60  	return aggregate
    61  }