Update the incremental merkle tree version and the Rust toolchain.

Use derived equality and ordering (which delegate to constant-time
versions) for note::nullifier::Nullifier and tree::MerkleHashOrchard
so that these types can be used as map keys in wallets.

.github/workflows/bench.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       - name: Run benchmark
         run: cargo bench -- --output-format bencher | tee output.txt

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       - name: Run tests
         uses: actions-rs/cargo@v1
@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       # Build benchmarks to prevent bitrot
       - name: Build benchmarks
@@ -46,7 +46,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       - name: Setup mdBook
         uses: peaceiris/actions-mdbook@v1
@@ -89,7 +89,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       - name: cargo fetch
         uses: actions-rs/cargo@v1
@@ -112,7 +112,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           override: true
       - run: rustup component add rustfmt
       - uses: actions-rs/cargo@v1

.github/workflows/lints-stable.yml

@@ -5,19 +5,19 @@ on: pull_request
 
 jobs:
   clippy:
-    name: Clippy (1.51.0)
+    name: Clippy (1.56.1)
     timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.51.0
+          toolchain: 1.56.1
           components: clippy
           override: true
       - name: Run Clippy
         uses: actions-rs/clippy-check@v1
         with:
-          name: Clippy (1.51.0)
+          name: Clippy (1.56.1)
           token: ${{ secrets.GITHUB_TOKEN }}
           args: --all-features --all-targets -- -D warnings

CHANGELOG.md

@@ -7,3 +7,6 @@ and this project adheres to Rust's notion of
 
 ## [Unreleased]
 Initial release!
+
+## [Removed]
+- The `std::hash::Hash` instance for `MerkleHashOrchard` has been removed.

Cargo.toml

@@ -46,6 +46,9 @@ incrementalmerkletree = "0.2"
 # Developer tooling dependencies
 plotters = { version = "0.3.0", optional = true }
 
+[patch.crates-io]
+incrementalmerkletree = { git = "https://github.com/zcash/incrementalmerkletree.git", rev = "23c0370b5414dc2ddd3305c6821bca5ea6fbf812" }
+
 [dev-dependencies]
 criterion = "0.3"
 hex = "0.4"

rust-toolchain

@@ -1 +1 @@
-1.51.0
+1.56.1

src/builder.rs

@@ -672,9 +672,9 @@ pub mod testing {
             for note in notes.iter() {
                 let leaf = MerkleHashOrchard::from_cmx(&note.commitment().into());
                 tree.append(&leaf);
-                tree.witness();
+                let (position, leaf) = tree.witness().unwrap();
 
-                let path = tree.authentication_path(&leaf).unwrap().into();
+                let path = MerklePath::from((position, tree.authentication_path(position, &leaf).unwrap()));
                 notes_and_auth_paths.push((*note, path));
             }
 

src/lib.rs

@@ -11,7 +11,7 @@
 // Temporary until we have more of the crate implemented.
 #![allow(dead_code)]
 // Catch documentation errors caused by code changes.
-#![deny(broken_intra_doc_links)]
+#![deny(rustdoc::broken_intra_doc_links)]
 #![deny(missing_debug_implementations)]
 #![deny(missing_docs)]
 #![deny(unsafe_code)]

src/note/nullifier.rs

@@ -11,7 +11,7 @@ use crate::{
 };
 
 /// A unique nullifier for a note.
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Nullifier(pub(crate) pallas::Base);
 
 impl Nullifier {

src/tree.rs

@@ -18,7 +18,7 @@ use serde::de::{Deserializer, Error};
 use serde::ser::Serializer;
 use serde::{Deserialize, Serialize};
 use std::iter;
-use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
+use subtle::{Choice, ConditionallySelectable, CtOption};
 
 // The uncommitted leaf is defined as pallas::Base(2).
 // <https://zips.z.cash/protocol/protocol.pdf#thmuncommittedorchard>
@@ -164,7 +164,7 @@ impl MerklePath {
 /// can produce a bottom value which needs to be accounted for in
 /// the production of a Merkle root. Leaf nodes are always wrapped
 /// with the `Some` constructor.
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct MerkleHashOrchard(pallas::Base);
 
 impl MerkleHashOrchard {
@@ -194,25 +194,6 @@ impl MerkleHashOrchard {
     }
 }
 
-/// This instance should only be used for hash table key comparisons.
-impl std::cmp::PartialEq for MerkleHashOrchard {
-    fn eq(&self, other: &Self) -> bool {
-        self.0.ct_eq(&other.0).into()
-    }
-}
-
-/// This instance should only be used for hash table key comparisons.
-impl std::cmp::Eq for MerkleHashOrchard {}
-
-/// This instance should only be used for hash table key hashing.
-impl std::hash::Hash for MerkleHashOrchard {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        <Option<pallas::Base>>::from(self.0)
-            .map(|b| b.to_bytes())
-            .hash(state)
-    }
-}
-
 impl ConditionallySelectable for MerkleHashOrchard {
     fn conditional_select(a: &Self, b: &Self, choice: Choice) -> Self {
         MerkleHashOrchard(pallas::Base::conditional_select(&a.0, &b.0, choice))
@@ -304,7 +285,7 @@ pub mod testing {
         {
             let cmx = MerkleHashOrchard::from_bytes(&tv.leaves[i]).unwrap();
             tree.append(&cmx);
-            tree.witness();
+            tree.witness().unwrap();
 
             assert_eq!(tree.root().0, pallas::Base::from_bytes(&tv.root).unwrap());
 
@@ -314,14 +295,13 @@ pub mod testing {
             for j in 0..=i {
                 let leaf = MerkleHashOrchard::from_bytes(&tv.leaves[j]).unwrap();
                 assert_eq!(
-                    tree.authentication_path(&leaf),
-                    Some((
-                        j.try_into().unwrap(),
+                    tree.authentication_path(j.try_into().unwrap(), &leaf),
+                    Some(
                         tv.paths[j]
                             .iter()
                             .map(|v| MerkleHashOrchard::from_bytes(v).unwrap())
                             .collect()
-                    ))
+                    )
                 );
             }
         }

tests/builder.rs

@@ -74,8 +74,8 @@ fn bundle_chain() {
         let leaf = MerkleHashOrchard::from_cmx(&cmx);
         let mut tree = BridgeTree::<MerkleHashOrchard, 32>::new(0);
         tree.append(&leaf);
-        tree.witness();
-        let (position, auth_path) = tree.authentication_path(&leaf).unwrap();
+        let (position, leaf) = tree.witness().unwrap();
+        let auth_path = tree.authentication_path(position, &leaf).unwrap();
         let merkle_path = MerklePath::from_parts(
             u64::from(position).try_into().unwrap(),
             auth_path[..].try_into().unwrap(),