Function Sm2Sign

sm2/sm2.go:126–166

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(priv *PrivateKey, msg, uid []byte, random io.Reader)

//****************************************************************************//

func Sm2Sign(priv *PrivateKey, msg, uid []byte, random io.Reader) (r, s *big.Int, err error) {
	digest, err := priv.PublicKey.Sm3Digest(msg, uid)
	if err != nil {
		return nil, nil, err
	}
	e := new(big.Int).SetBytes(digest)
	c := priv.PublicKey.Curve
	N := c.Params().N
	if N.Sign() == 0 {
		return nil, nil, errZeroParam
	}
	var k *big.Int
	for { // 调整算法细节以实现SM2
		for {
			k, err = randFieldElement(c, random)
			if err != nil {
				r = nil
				return
			}
			r, _ = priv.Curve.ScalarBaseMult(k.Bytes())
			r.Add(r, e)
			r.Mod(r, N)
			if r.Sign() != 0 {
				if t := new(big.Int).Add(r, k); t.Cmp(N) != 0 {
					break
				}
			}

		}
		rD := new(big.Int).Mul(priv.D, r)
		s = new(big.Int).Sub(k, rD)
		d1 := new(big.Int).Add(priv.D, one)
		d1Inv := new(big.Int).ModInverse(d1, N)
		s.Mul(s, d1Inv)
		s.Mod(s, N)
		if s.Sign() != 0 {
			break
		}
	}
	return
}
func Sm2Verify(pub *PublicKey, msg, uid []byte, r, s *big.Int) bool {
	c := pub.Curve
	N := c.Params().N