diff --git a/src/crypto/elliptic/elliptic.go b/src/crypto/elliptic/elliptic.go index 35aacf24e5152..76b78a790ea01 100644 --- a/src/crypto/elliptic/elliptic.go +++ b/src/crypto/elliptic/elliptic.go @@ -210,8 +210,9 @@ func (curve *CurveParams) doubleJacobian(x, y, z *big.Int) (*big.Int, *big.Int, x3 := new(big.Int).Mul(alpha, alpha) beta8 := new(big.Int).Lsh(beta, 3) + beta8.Mod(beta8, curve.P) x3.Sub(x3, beta8) - for x3.Sign() == -1 { + if x3.Sign() == -1 { x3.Add(x3, curve.P) } x3.Mod(x3, curve.P)