From ea7e2e3a9e3122e9f2c0082f94641ed16f869d28 Mon Sep 17 00:00:00 2001
From: Tony Arcieri <bascule@gmail.com>
Date: Wed, 26 Aug 2020 12:47:35 -0700
Subject: [PATCH] elliptic-curve: conditionally impl Invert for NonZeroScalar

...if the underlying scalar type it wraps also impls `Invert`
---
 elliptic-curve/src/scalar.rs | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/elliptic-curve/src/scalar.rs b/elliptic-curve/src/scalar.rs
index 957d7bd74..78946fe02 100644
--- a/elliptic-curve/src/scalar.rs
+++ b/elliptic-curve/src/scalar.rs
@@ -1,6 +1,6 @@
 //! Scalar types
 
-use crate::{Arithmetic, Curve, ElementBytes, FromBytes};
+use crate::{ops::Invert, Arithmetic, Curve, ElementBytes, FromBytes};
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
 #[cfg(feature = "rand")]
@@ -84,6 +84,19 @@ where
     }
 }
 
+impl<C> Invert for NonZeroScalar<C>
+where
+    C: Curve + Arithmetic,
+    C::Scalar: Invert,
+{
+    type Output = <C::Scalar as Invert>::Output;
+
+    /// Perform a scalar inversion
+    fn invert(&self) -> CtOption<Self::Output> {
+        self.scalar.invert()
+    }
+}
+
 #[cfg(feature = "rand")]
 impl<C> Generate for NonZeroScalar<C>
 where