Merge pull request #5 from iden3/decompress-modsqrt return error if no ModSqrt(x, q) exist in babyjubjub decompress point
Eduard S eduard@iden3.io
Tue, 10 Sep 2019 10:48:18 +0200
1 files changed,
4 insertions(+),
1 deletions(-)
jump to
M
babyjub/babyjub.go
→
babyjub/babyjub.go
@@ -203,7 +203,10 @@ }
xb.ModInverse(xb, constants.Q) p.X.Mul(xa, xb) // xa / xb p.X.Mod(p.X, constants.Q) - p.X.ModSqrt(p.X, constants.Q) + noSqrt := p.X.ModSqrt(p.X, constants.Q) + if noSqrt == nil { + return nil, fmt.Errorf("x is not a square mod q") + } if (sign && !PointCoordSign(p.X)) || (!sign && PointCoordSign(p.X)) { p.X.Mul(p.X, constants.MinusOne) }