Governance wallet support for shielded voting (zodl 3.4.0, pre-orchard 0.13)

.github/helpers/check-dep-graph.py

@@ -32,6 +32,14 @@
     'zip32',
 ])
 
+# Maps cargo package names to the logical name used in README.md's mermaid graph.
+# The workspace imports `orchard` via the `valar-orchard` crates.io package using
+# cargo's `package = "valar-orchard"` rename, so `cargo tree` reports the real
+# package name `valar-orchard` while the README uses the alias `orchard`.
+PACKAGE_NAME_REMAP = {
+    'valar-orchard': 'orchard',
+}
+
 def main():
     script_dir = os.path.dirname(os.path.realpath(__file__))
     base_dir = os.path.dirname(os.path.dirname(script_dir))
@@ -79,6 +87,7 @@ def main():
             continue
         (depth, crate, _) = line.strip().split(' ', 2)
         depth = int(depth)
+        crate = PACKAGE_NAME_REMAP.get(crate, crate)
 
         if depth == 0:
             crate_stack = [crate]

Cargo.toml

@@ -68,7 +68,14 @@ redjubjub = { version = "0.8", default-features = false }
 sapling = { package = "sapling-crypto", version = "0.6.2", default-features = false }
 
 # - Orchard
-orchard = { version = "0.12", default-features = false }
+#
+# Points at the Valar Group `valar-orchard` fork on crates.io, aliased locally to
+# `orchard` so every member still writes `use orchard::…`. The fork is
+# upstream-0.12.0 + post-release fixes (up to zcash/orchard 6b12c77) + governance-
+# visibility additions needed by the shielded-voting circuits in
+# valargroup/voting-circuits. Drop back to `orchard = "0.12"` once those
+# visibility changes land in zcash/orchard upstream.
+orchard = { version = "0.12.0", package = "valar-orchard", default-features = false }
 pasta_curves = "0.5"
 
 # - Transparent
@@ -231,4 +238,6 @@ unexpected_cfgs = { level = "warn", check-cfg = [
 
 [patch.crates-io]
 sapling = { package = "sapling-crypto", git = "https://github.com/zcash/sapling-crypto.git", rev = "b8a81c22f034d68f9bbd6cba728aab807b9ba2ea" }
-orchard = { package = "orchard", git = "https://github.com/zcash/orchard.git", rev = "b0bf2670e248958c6ce7c1deed466032e0dbd4d9" }
+# No orchard patch: the workspace resolves `orchard` via its `package = "valar-orchard"`
+# alias on crates.io, which already carries the post-0.12.0 upstream fixes plus the
+# governance-visibility additions.

pczt/CHANGELOG.md

@@ -14,6 +14,7 @@ workspace.
 - `pczt::ExtractError`
 - `pczt::EffectsOnly`
 - `pczt::orchard::Spend::spend_auth_sig` getter (via `getset`).
+- `pczt::roles::signer::Signer::shielded_sighash` getter.
 - `pczt::roles::signer`:
   - `Signer::sighash`
   - `Signer::append_transparent_signature`

pczt/src/roles/signer/mod.rs

@@ -80,7 +80,7 @@ impl Signer {
     /// Calculates the signature digest that must be signed to authorize shielded spends.
     ///
     /// This can be used to produce a signature externally suitable for passing to e.g.
-    /// [`Self::apply_orchard_signature`].}
+    /// [`Self::apply_orchard_signature`].
     pub fn shielded_sighash(&self) -> [u8; 32] {
         self.shielded_sighash
     }
@@ -89,7 +89,7 @@ impl Signer {
     /// spend at the given index.
     ///
     /// This can be used to produce a signature externally suitable for passing to e.g.
-    /// [`Self::append_transparent_signature`].}
+    /// [`Self::append_transparent_signature`].
     ///
     /// Returns an error if `index` is invalid for this PCZT.
     pub fn transparent_sighash(&self, index: usize) -> Result<[u8; 32], Error> {

supply-chain/config.toml

@@ -844,10 +844,6 @@ criteria = "safe-to-deploy"
 version = "11.1.4"
 criteria = "safe-to-deploy"
 
-[[exemptions.orchard]]
-version = "0.12.0@git:b0bf2670e248958c6ce7c1deed466032e0dbd4d9"
-criteria = "safe-to-deploy"
-
 [[exemptions.ordered-float]]
 version = "2.10.1"
 criteria = "safe-to-deploy"
@@ -1588,6 +1584,10 @@ criteria = "safe-to-deploy"
 version = "1.8.0"
 criteria = "safe-to-deploy"
 
+[[exemptions.valar-orchard]]
+version = "0.12.0"
+criteria = "safe-to-deploy"
+
 [[exemptions.wait-timeout]]
 version = "0.2.0"
 criteria = "safe-to-deploy"

zcash_client_sqlite/CHANGELOG.md

@@ -30,6 +30,22 @@ workspace.
 - `impl<'conn, P, CL, R> WalletWrite for WalletDb<SqlTransaction<'conn>, P, CL, R>` to
   enable calling `WalletWrite` methods inside `WalletDb::transactionally` (amortizing the
   database transaction overhead).
+- `WalletDb::get_unspent_orchard_notes_at_historical_height` returns all Orchard
+  notes that existed and were unspent at a given height.
+- `WalletDb::generate_orchard_witnesses_at_historical_height` generates Merkle
+  witnesses at a historical height using an ephemeral in-memory
+  `shardtree::store::memory::MemoryShardStore`.
+- Two new `orchard`-gated variants have been added to
+  `zcash_client_sqlite::error::SqliteClientError` to surface the failure modes
+  of `WalletDb::generate_orchard_witnesses_at_historical_height`:
+  - `HistoricalFrontierInvalid(shardtree::error::InsertionError)` —
+    the caller-supplied frontier is inconsistent with the shard data
+    reconstructed from the wallet at the requested height.
+  - `HistoricalWitnessUnavailable { position, height }` — no witness can be
+    produced for the specified position at the specified height (the wallet
+    most likely has not synced through that height).
+  Shard-read failures continue to surface via the existing
+  `SqliteClientError::CommitmentTree` variant.
 
 ### Changed
 - The `accounts` table now stores IVK item caches instead of FVK item caches for

zcash_client_sqlite/src/error.rs

@@ -3,7 +3,11 @@
 use std::error;
 use std::fmt;
 
+#[cfg(feature = "orchard")]
+use incrementalmerkletree::Position;
 use nonempty::NonEmpty;
+#[cfg(feature = "orchard")]
+use shardtree::error::InsertionError;
 use shardtree::error::ShardTreeError;
 
 #[cfg(feature = "transparent-key-import")]
@@ -116,6 +120,35 @@ pub enum SqliteClientError {
     /// commitment trees.
     CommitmentTree(ShardTreeError<commitment_tree::Error>),
 
+    /// The caller-supplied frontier passed to
+    /// [`WalletDb::generate_orchard_witnesses_at_historical_height`] is
+    /// inconsistent with the shard data reconstructed from the wallet at the
+    /// requested height.
+    ///
+    /// [`WalletDb::generate_orchard_witnesses_at_historical_height`]:
+    /// crate::WalletDb::generate_orchard_witnesses_at_historical_height
+    #[cfg(feature = "orchard")]
+    HistoricalFrontierInvalid(InsertionError),
+
+    /// A witness could not be generated for the specified position at the
+    /// specified historical height in a call to
+    /// [`WalletDb::generate_orchard_witnesses_at_historical_height`].
+    ///
+    /// The wallet most likely has not synced through `height`, the checkpoint
+    /// at `height` has been pruned, or `position` does not belong to the
+    /// wallet.
+    ///
+    /// [`WalletDb::generate_orchard_witnesses_at_historical_height`]:
+    /// crate::WalletDb::generate_orchard_witnesses_at_historical_height
+    #[cfg(feature = "orchard")]
+    HistoricalWitnessUnavailable {
+        /// The note commitment tree position for which a witness was
+        /// requested.
+        position: Position,
+        /// The historical height at which the witness was requested.
+        height: BlockHeight,
+    },
+
     /// The block at the specified height was not available from the block cache.
     CacheMiss(BlockHeight),
 
@@ -187,6 +220,8 @@ impl error::Error for SqliteClientError {
             SqliteClientError::Io(e) => Some(e),
             SqliteClientError::BalanceError(e) => Some(e),
             SqliteClientError::AddressGeneration(e) => Some(e),
+            #[cfg(feature = "orchard")]
+            SqliteClientError::HistoricalFrontierInvalid(e) => Some(e),
             _ => None,
         }
     }
@@ -272,6 +307,17 @@ impl fmt::Display for SqliteClientError {
                 f,
                 "An error occurred accessing or updating note commitment tree data: {err}."
             ),
+            #[cfg(feature = "orchard")]
+            SqliteClientError::HistoricalFrontierInvalid(err) => write!(
+                f,
+                "The frontier supplied to generate_orchard_witnesses_at_historical_height is inconsistent with the wallet's shard data: {err}"
+            ),
+            #[cfg(feature = "orchard")]
+            SqliteClientError::HistoricalWitnessUnavailable { position, height } => write!(
+                f,
+                "No witness is available for position {} at height {height} (the wallet may need to sync through this height).",
+                u64::from(*position),
+            ),
             SqliteClientError::CacheMiss(height) => write!(
                 f,
                 "Requested height {height} does not exist in the block cache."