From 760f82e79e717ffc3f27ceb7c3c1cc350d20b39e Mon Sep 17 00:00:00 2001
From: Filippo Valsorda <hi@filippo.io>
Date: Wed, 15 May 2019 14:36:17 -0400
Subject: [PATCH] ristretto255: add Scalar.Invert

---
 scalar.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/scalar.go b/scalar.go
index cce86d4..0b7531f 100644
--- a/scalar.go
+++ b/scalar.go
@@ -45,6 +45,14 @@ func (s *Scalar) Multiply(x, y *Scalar) *Scalar {
 	return s
 }
 
+// Invert sets s = 1 / x such that s * x = 1 mod l and returns s.
+//
+// If x is 0, the result is undefined.
+func (s *Scalar) Invert(x *Scalar) *Scalar {
+	s.s.Inv(&x.s)
+	return s
+}
+
 // FromUniformBytes sets s to an uniformly distributed value given 64 uniformly
 // distributed random bytes.
 func (s *Scalar) FromUniformBytes(x []byte) *Scalar {