Merge pull request #311 from str4d/zcash_client_sqlite-0.2.1

zcash_client_sqlite: Read rcm correctly from data DB after Canopy

zcash_client_sqlite/CHANGELOG.md

@@ -0,0 +1,12 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to Rust's notion of
+[Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [0.2.1] - 2020-10-24
+### Fixed
+- `transact::create_to_address` now correctly reconstructs notes from the data
+  DB after Canopy activation (zcash/librustzcash#311). This is critcal to correct
+  operation of spends after Canopy.

zcash_client_sqlite/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "zcash_client_sqlite"
 description = "An SQLite-based Zcash light client"
-version = "0.2.0"
+version = "0.2.1"
 authors = [
     "Jack Grigg <jack@z.cash>",
 ]

zcash_client_sqlite/src/transact.rs

@@ -6,7 +6,7 @@ use std::convert::TryInto;
 use std::path::Path;
 use zcash_client_backend::{address::RecipientAddress, encoding::encode_extended_full_viewing_key};
 use zcash_primitives::{
-    consensus::{self, NetworkUpgrade},
+    consensus,
     keys::OutgoingViewingKey,
     merkle_tree::{IncrementalWitness, MerklePath},
     note_encryption::Memo,
@@ -228,21 +228,18 @@ pub fn create_to_address<DB: AsRef<Path>, P: consensus::Parameters>(
             let note_value: i64 = row.get(1)?;
 
             let rseed = {
-                let d: Vec<_> = row.get(2)?;
+                let rcm_bytes: Vec<_> = row.get(2)?;
 
-                if params.is_nu_active(NetworkUpgrade::Canopy, height) {
-                    let mut r = [0u8; 32];
-                    r.copy_from_slice(&d[..]);
-                    Rseed::AfterZip212(r)
-                } else {
-                    let r = jubjub::Fr::from_repr(
-                        d[..]
-                            .try_into()
-                            .map_err(|_| Error(ErrorKind::InvalidNote))?,
-                    )
-                    .ok_or(Error(ErrorKind::InvalidNote))?;
-                    Rseed::BeforeZip212(r)
-                }
+                // We store rcm directly in the data DB, regardless of whether the note
+                // used a v1 or v2 note plaintext, so for the purposes of spending let's
+                // pretend this is a pre-ZIP 212 note.
+                let rcm = jubjub::Fr::from_repr(
+                    rcm_bytes[..]
+                        .try_into()
+                        .map_err(|_| Error(ErrorKind::InvalidNote))?,
+                )
+                .ok_or(Error(ErrorKind::InvalidNote))?;
+                Rseed::BeforeZip212(rcm)
             };
 
             let from = extfvk.fvk.vk.to_payment_address(diversifier).unwrap();