elliptic-curve: add missing Debug impls (#1675)

elliptic-curve/src/ecdh.rs

@@ -30,7 +30,7 @@ use crate::{
     point::AffineCoordinates, AffinePoint, Curve, CurveArithmetic, FieldBytes, NonZeroScalar,
     ProjectivePoint, PublicKey,
 };
-use core::borrow::Borrow;
+use core::{borrow::Borrow, fmt};
 use digest::{crypto_common::BlockSizeUser, Digest};
 use group::Curve as _;
 use hkdf::{hmac::SimpleHmac, Hkdf};
@@ -97,6 +97,12 @@ where
     scalar: NonZeroScalar<C>,
 }
 
+impl<C: CurveArithmetic> fmt::Debug for EphemeralSecret<C> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("EphemeralSecret").finish_non_exhaustive()
+    }
+}
+
 impl<C> EphemeralSecret<C>
 where
     C: CurveArithmetic,
@@ -157,6 +163,12 @@ pub struct SharedSecret<C: Curve> {
     secret_bytes: FieldBytes<C>,
 }
 
+impl<C: Curve> fmt::Debug for SharedSecret<C> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("SharedSecret").finish_non_exhaustive()
+    }
+}
+
 impl<C: Curve> SharedSecret<C> {
     /// Create a new [`SharedSecret`] from an [`AffinePoint`] for this curve.
     #[inline]

elliptic-curve/src/hash2curve/hash2field/expand_msg.rs

@@ -43,6 +43,7 @@ pub trait Expander {
 /// Implements [section 5.4.3 of `draft-irtf-cfrg-hash-to-curve-13`][dst].
 ///
 /// [dst]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-13#section-5.4.3
+#[derive(Debug)]
 pub(crate) enum Domain<'a, L>
 where
     L: ArraySize + IsLess<U256>,

elliptic-curve/src/hash2curve/hash2field/expand_msg/xmd.rs

@@ -20,6 +20,7 @@ use digest::{
 /// - `len_in_bytes == 0`
 /// - `len_in_bytes > u16::MAX`
 /// - `len_in_bytes > 255 * HashT::OutputSize`
+#[derive(Debug)]
 pub struct ExpandMsgXmd<HashT>(PhantomData<HashT>)
 where
     HashT: BlockSizeUser + Default + FixedOutput + HashMarker,
@@ -87,6 +88,7 @@ where
 }
 
 /// [`Expander`] type for [`ExpandMsgXmd`].
+#[derive(Debug)]
 pub struct ExpanderXmd<'a, HashT>
 where
     HashT: BlockSizeUser + Default + FixedOutput + HashMarker,

elliptic-curve/src/hash2curve/hash2field/expand_msg/xof.rs

@@ -2,6 +2,7 @@
 
 use super::{Domain, ExpandMsg, Expander};
 use crate::{Error, Result};
+use core::fmt;
 use digest::{ExtendableOutput, Update, XofReader};
 use hybrid_array::typenum::U32;
 
@@ -18,6 +19,18 @@ where
     reader: <HashT as ExtendableOutput>::Reader,
 }
 
+impl<HashT> fmt::Debug for ExpandMsgXof<HashT>
+where
+    HashT: Default + ExtendableOutput + Update,
+    <HashT as ExtendableOutput>::Reader: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("ExpandMsgXof")
+            .field("reader", &self.reader)
+            .finish()
+    }
+}
+
 /// ExpandMsgXof implements `expand_message_xof` for the [`ExpandMsg`] trait
 impl<'a, HashT> ExpandMsg<'a> for ExpandMsgXof<HashT>
 where

elliptic-curve/src/hash2curve/isogeny.rs

@@ -7,6 +7,7 @@ use ff::Field;
 use hybrid_array::{typenum::Unsigned, Array, ArraySize};
 
 /// The coefficients for mapping from one isogenous curve to another
+#[derive(Debug)]
 pub struct IsogenyCoefficients<F: Field + AddAssign + Mul<Output = F>> {
     /// The coefficients for the x numerator
     pub xnum: &'static [F],

elliptic-curve/src/hash2curve/osswu.rs

@@ -8,6 +8,7 @@ use subtle::ConditionallySelectable;
 use subtle::ConstantTimeEq;
 
 /// The Optimized Simplified Shallue-van de Woestijne-Ulas parameters
+#[derive(Debug)]
 pub struct OsswuMapParams<F>
 where
     F: Field,

elliptic-curve/src/lib.rs

@@ -18,6 +18,7 @@
     clippy::panic,
     clippy::panic_in_result_fn,
     clippy::unwrap_used,
+    missing_debug_implementations,
     missing_docs,
     rust_2018_idioms,
     unused_lifetimes,

elliptic-curve/src/point/non_identity.rs

@@ -17,7 +17,7 @@ use crate::{CurveArithmetic, NonZeroScalar, Scalar};
 ///
 /// In the context of ECC, it's useful for ensuring that certain arithmetic
 /// cannot result in the identity point.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub struct NonIdentity<P> {
     point: P,
 }

elliptic-curve/src/scalar/blinded.rs

@@ -2,6 +2,7 @@
 
 use super::Scalar;
 use crate::{ops::Invert, CurveArithmetic};
+use core::fmt;
 use group::ff::Field;
 use rand_core::CryptoRngCore;
 use subtle::CtOption;
@@ -26,6 +27,12 @@ where
     mask: Scalar<C>,
 }
 
+impl<C: CurveArithmetic> fmt::Debug for BlindedScalar<C> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BlindedScalar").finish_non_exhaustive()
+    }
+}
+
 impl<C> BlindedScalar<C>
 where
     C: CurveArithmetic,

elliptic-curve/src/scalar/nonzero.rs

@@ -36,6 +36,12 @@ where
     scalar: Scalar<C>,
 }
 
+impl<C: CurveArithmetic> fmt::Debug for NonZeroScalar<C> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("NonZeroScalar").finish_non_exhaustive()
+    }
+}
+
 impl<C> NonZeroScalar<C>
 where
     C: CurveArithmetic,