From 5d78ab3508dcd1f9a4ae730024126ba9b9f53ea2 Mon Sep 17 00:00:00 2001
From: Kris Nuttycombe <kris@nutty.land>
Date: Mon, 26 Jul 2021 12:05:28 -0600
Subject: [PATCH] Add Eq and Ord implementations for Orchard keys.

---
 src/keys.rs                 | 20 +++++++++++---------
 src/primitives/redpallas.rs | 15 +++++++++++++++
 src/spec.rs                 |  2 +-
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/keys.rs b/src/keys.rs
index 152e3e62..708a546f 100644
--- a/src/keys.rs
+++ b/src/keys.rs
@@ -29,7 +29,7 @@ const KDF_ORCHARD_PERSONALIZATION: &[u8; 16] = b"Zcash_OrchardKDF";
 /// Defined in [Zcash Protocol Spec § 4.2.3: Orchard Key Components][orchardkeycomponents].
 ///
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct SpendingKey([u8; 32]);
 
 impl SpendingKey {
@@ -111,7 +111,7 @@ impl From<&SpendingKey> for SpendAuthorizingKey {
 /// $\mathsf{ak}$ but stored here as a RedPallas verification key.
 ///
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialOrd, Ord)]
 pub struct SpendValidatingKey(redpallas::VerificationKey<SpendAuth>);
 
 impl From<&SpendAuthorizingKey> for SpendValidatingKey {
@@ -132,6 +132,8 @@ impl PartialEq for SpendValidatingKey {
     }
 }
 
+impl Eq for SpendValidatingKey {}
+
 impl SpendValidatingKey {
     /// Randomizes this spend validating key with the given `randomizer`.
     pub fn randomize(&self, randomizer: &pallas::Scalar) -> redpallas::VerificationKey<SpendAuth> {
@@ -158,7 +160,7 @@ impl SpendValidatingKey {
 /// [`Nullifier`]: crate::note::Nullifier
 /// [`Note`]: crate::note::Note
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Copy, Debug, Clone)]
+#[derive(Copy, Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub(crate) struct NullifierDerivingKey(pallas::Base);
 
 impl NullifierDerivingKey {
@@ -199,7 +201,7 @@ impl NullifierDerivingKey {
 /// Defined in [Zcash Protocol Spec § 4.2.3: Orchard Key Components][orchardkeycomponents].
 ///
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Copy, Debug, Clone)]
+#[derive(Copy, Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub(crate) struct CommitIvkRandomness(pallas::Scalar);
 
 impl From<&SpendingKey> for CommitIvkRandomness {
@@ -237,7 +239,7 @@ impl CommitIvkRandomness {
 /// Defined in [Zcash Protocol Spec § 4.2.3: Orchard Key Components][orchardkeycomponents].
 ///
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct FullViewingKey {
     ak: SpendValidatingKey,
     nk: NullifierDerivingKey,
@@ -326,7 +328,7 @@ impl FullViewingKey {
 /// Defined in [Zcash Protocol Spec § 4.2.3: Orchard Key Components][orchardkeycomponents].
 ///
 /// [orchardkeycomponents]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct DiversifierKey([u8; 32]);
 
 impl From<&FullViewingKey> for DiversifierKey {
@@ -336,7 +338,7 @@ impl From<&FullViewingKey> for DiversifierKey {
 }
 
 /// The index for a particular diversifier.
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct DiversifierIndex([u8; 11]);
 
 macro_rules! di_from {
@@ -418,7 +420,7 @@ impl Diversifier {
 /// decryption of notes). When we actually want to serialize ivk, we're guaranteed to get
 /// a valid base field element encoding, because we always construct ivk from an integer
 /// in the correct range.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 struct KeyAgreementPrivateKey(NonZeroPallasScalar);
 
 impl From<&FullViewingKey> for KeyAgreementPrivateKey {
@@ -455,7 +457,7 @@ impl KeyAgreementPrivateKey {
 /// Defined in [Zcash Protocol Spec § 5.6.4.3: Orchard Raw Incoming Viewing Keys][orchardinviewingkeyencoding].
 ///
 /// [orchardinviewingkeyencoding]: https://zips.z.cash/protocol/nu5.pdf#orchardinviewingkeyencoding
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct IncomingViewingKey {
     dk: DiversifierKey,
     ivk: KeyAgreementPrivateKey,
diff --git a/src/primitives/redpallas.rs b/src/primitives/redpallas.rs
index f367c0b8..38de97f9 100644
--- a/src/primitives/redpallas.rs
+++ b/src/primitives/redpallas.rs
@@ -1,5 +1,6 @@
 //! A minimal RedPallas implementation for use in Zcash.
 
+use std::cmp::{Ord, Ordering, PartialOrd};
 use std::convert::{TryFrom, TryInto};
 
 use pasta_curves::pallas;
@@ -97,6 +98,20 @@ impl<T: SigType> PartialEq for VerificationKey<T> {
     }
 }
 
+impl<T: SigType> Eq for VerificationKey<T> {}
+
+impl<T: SigType> PartialOrd for VerificationKey<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        <[u8; 32]>::from(self).partial_cmp(&<[u8; 32]>::from(other))
+    }
+}
+
+impl<T: SigType> Ord for VerificationKey<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        <[u8; 32]>::from(self).cmp(&<[u8; 32]>::from(other))
+    }
+}
+
 impl VerificationKey<SpendAuth> {
     /// Used in the note encryption tests.
     #[cfg(test)]
diff --git a/src/spec.rs b/src/spec.rs
index 31cf1c95..0ffd4cb2 100644
--- a/src/spec.rs
+++ b/src/spec.rs
@@ -93,7 +93,7 @@ impl NonZeroPallasBase {
 }
 
 /// An integer in [1..r_P].
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub(crate) struct NonZeroPallasScalar(pallas::Scalar);
 
 impl Default for NonZeroPallasScalar {