Implement From<NonIdentity> for Projective/AffinePoint (#1190)

Author: daxpedda

k256/src/arithmetic/affine.rs

@@ -8,7 +8,7 @@ use core::ops::{Mul, Neg};
 use elliptic_curve::{
     Error, Result,
     group::{GroupEncoding, prime::PrimeCurveAffine},
-    point::{AffineCoordinates, DecompactPoint, DecompressPoint},
+    point::{AffineCoordinates, DecompactPoint, DecompressPoint, NonIdentity},
     sec1::{self, FromEncodedPoint, ToEncodedPoint},
     subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption},
     zeroize::DefaultIsZeroes,
@@ -311,6 +311,12 @@ impl From<&AffinePoint> for EncodedPoint {
     }
 }
 
+impl From<NonIdentity<AffinePoint>> for AffinePoint {
+    fn from(affine_point: NonIdentity<AffinePoint>) -> Self {
+        affine_point.to_point()
+    }
+}
+
 impl From<PublicKey> for AffinePoint {
     fn from(public_key: PublicKey) -> AffinePoint {
         *public_key.as_affine()

k256/src/arithmetic/projective.rs

@@ -8,7 +8,6 @@ use core::{
     iter::Sum,
     ops::{Add, AddAssign, Neg, Sub, SubAssign},
 };
-use elliptic_curve::ops::BatchInvert;
 use elliptic_curve::{
     BatchNormalize, Error, Result,
     group::{
@@ -21,6 +20,7 @@ use elliptic_curve::{
     subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption},
     zeroize::DefaultIsZeroes,
 };
+use elliptic_curve::{ops::BatchInvert, point::NonIdentity};
 
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
@@ -318,6 +318,12 @@ impl From<&AffinePoint> for ProjectivePoint {
     }
 }
 
+impl From<NonIdentity<ProjectivePoint>> for ProjectivePoint {
+    fn from(p: NonIdentity<ProjectivePoint>) -> Self {
+        p.to_point()
+    }
+}
+
 impl From<ProjectivePoint> for AffinePoint {
     fn from(p: ProjectivePoint) -> AffinePoint {
         p.to_affine()

primeorder/src/affine.rs

@@ -12,7 +12,7 @@ use elliptic_curve::{
     array::ArraySize,
     ff::{Field, PrimeField},
     group::{GroupEncoding, prime::PrimeCurveAffine},
-    point::{AffineCoordinates, DecompactPoint, DecompressPoint, Double},
+    point::{AffineCoordinates, DecompactPoint, DecompressPoint, Double, NonIdentity},
     sec1::{
         self, CompressedPoint, EncodedPoint, FromEncodedPoint, ModulusSize, ToCompactEncodedPoint,
         ToEncodedPoint, UncompressedPointSize,
@@ -194,6 +194,15 @@ where
     }
 }
 
+impl<C> From<NonIdentity<AffinePoint<C>>> for AffinePoint<C>
+where
+    C: PrimeCurveParams,
+{
+    fn from(affine: NonIdentity<AffinePoint<C>>) -> Self {
+        affine.to_point()
+    }
+}
+
 impl<C> From<ProjectivePoint<C>> for AffinePoint<C>
 where
     C: PrimeCurveParams,

primeorder/src/projective.rs

@@ -18,7 +18,7 @@ use elliptic_curve::{
         prime::{PrimeCurve, PrimeGroup},
     },
     ops::{BatchInvert, LinearCombination},
-    point::Double,
+    point::{Double, NonIdentity},
     rand_core::TryRngCore,
     sec1::{
         CompressedPoint, EncodedPoint, FromEncodedPoint, ModulusSize, ToEncodedPoint,
@@ -238,6 +238,15 @@ where
     }
 }
 
+impl<C> From<NonIdentity<ProjectivePoint<C>>> for ProjectivePoint<C>
+where
+    C: PrimeCurveParams,
+{
+    fn from(p: NonIdentity<ProjectivePoint<C>>) -> Self {
+        p.to_point()
+    }
+}
+
 impl<C> From<PublicKey<C>> for ProjectivePoint<C>
 where
     C: PrimeCurveParams,