From 009e1dd37e5bebee6d58dcb8ebe6baeeee1d3c6c Mon Sep 17 00:00:00 2001
From: Deirdre Connolly <deirdre@zfnd.org>
Date: Sun, 14 Mar 2021 05:39:09 -0400
Subject: [PATCH] Orchard: some Action (de)serialization fixes

---
 zebra-chain/src/orchard/action.rs        |  4 ++--
 zebra-chain/src/transaction/serialize.rs | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/zebra-chain/src/orchard/action.rs b/zebra-chain/src/orchard/action.rs
index 097c6531..01df0346 100644
--- a/zebra-chain/src/orchard/action.rs
+++ b/zebra-chain/src/orchard/action.rs
@@ -43,9 +43,9 @@ pub struct Action {
 impl ZcashSerialize for Action {
     fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
         self.cv.zcash_serialize(&mut writer)?;
-        writer.write_32_bytes(self.nullifier.into())?;
+        writer.write_all(&<[u8; 32]>::from(self.nullifier)[..])?;
         writer.write_all(&<[u8; 32]>::from(self.rk)[..])?;
-        writer.write_all(self.cm_x.to_bytes())?;
+        writer.write_all(&<[u8; 32]>::from(self.cm_x)[..])?;
         self.ephemeral_key.zcash_serialize(&mut writer)?;
         self.enc_ciphertext.zcash_serialize(&mut writer)?;
         self.out_ciphertext.zcash_serialize(&mut writer)?;
diff --git a/zebra-chain/src/transaction/serialize.rs b/zebra-chain/src/transaction/serialize.rs
index b60d1b22..4dad887c 100644
--- a/zebra-chain/src/transaction/serialize.rs
+++ b/zebra-chain/src/transaction/serialize.rs
@@ -4,7 +4,7 @@
 use std::{convert::TryInto, io, sync::Arc};
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
-use halo2::pasta::pallas;
+use halo2::{arithmetic::FieldExt, pasta::pallas};
 
 use crate::{
     block::MAX_BLOCK_BYTES,
@@ -49,6 +49,20 @@ impl ZcashDeserialize for pallas::Scalar {
     }
 }
 
+impl ZcashDeserialize for pallas::Base {
+    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        let possible_field_element = pallas::Base::from_bytes(&reader.read_32_bytes()?);
+
+        if possible_field_element.is_some().into() {
+            Ok(possible_field_element.unwrap())
+        } else {
+            Err(SerializationError::Parse(
+                "Invalid pallas::Base, input not canonical",
+            ))
+        }
+    }
+}
+
 impl<P: ZkSnarkProof> ZcashSerialize for JoinSplitData<P> {
     fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
         writer.write_compactsize(self.joinsplits().count() as u64)?;