ed448-goldilocks: expose CurveWithScalar

Author: baloo

ed448-goldilocks/src/field.rs

@@ -2,9 +2,9 @@ mod element;
 mod scalar;
 
 pub(crate) use element::*;
-pub(crate) use scalar::CurveWithScalar;
 pub use scalar::{
-    MODULUS_LIMBS, NZ_ORDER, ORDER, Scalar, ScalarBytes, WIDE_ORDER, WideScalarBytes,
+    CurveWithScalar, MODULUS_LIMBS, NZ_ORDER, ORDER, Scalar, ScalarBytes, WIDE_ORDER,
+    WideScalarBytes,
 };
 
 use crate::curve::twedwards::extended::ExtendedPoint as TwExtendedPoint;

ed448-goldilocks/src/field/scalar.rs

@@ -41,13 +41,18 @@ pub type ScalarBytes<C> = Array<u8, <C as CurveWithScalar>::ReprSize>;
 /// The number of bytes needed to represent the safely create a scalar from a random bytes
 pub type WideScalarBytes<C> = Array<u8, Prod<<C as CurveWithScalar>::ReprSize, U2>>;
 
+/// Representation of a curve scalar for either Ed448 or Decaf448
 pub trait CurveWithScalar: 'static + CurveArithmetic + Send + Sync {
+    /// The size of the scalar for the given curve
     type ReprSize: ArraySize<ArrayType<u8>: Copy> + Mul<U2, Output: ArraySize<ArrayType<u8>: Copy>>;
 
+    /// Create a scalar from the wide representation
     fn from_bytes_mod_order_wide(input: &WideScalarBytes<Self>) -> Scalar<Self>;
 
+    /// Create a scalar from its serialization
     fn from_canonical_bytes(bytes: &ScalarBytes<Self>) -> CtOption<Scalar<Self>>;
 
+    /// Return the serialization for a given scalar
     fn to_repr(scalar: &Scalar<Self>) -> ScalarBytes<Self>;
 }
 

ed448-goldilocks/src/lib.rs

@@ -60,8 +60,8 @@ pub use edwards::{
     AffinePoint, CompressedEdwardsY, EdwardsPoint, EdwardsScalar, EdwardsScalarBytes,
     WideEdwardsScalarBytes,
 };
-pub use field::{MODULUS_LIMBS, ORDER, Scalar, WIDE_ORDER};
 pub use montgomery::{MontgomeryPoint, ProjectiveMontgomeryPoint};
+pub use field::{CurveWithScalar, MODULUS_LIMBS, ORDER, Scalar, WIDE_ORDER};
 pub use ristretto::{CompressedRistretto, RistrettoPoint};
 #[cfg(feature = "signing")]
 pub use sign::*;