From ff64cde0e81222972b8a73f8c8e7547481678c86 Mon Sep 17 00:00:00 2001
From: Vivek Arte <vivek@qed-it.com>
Date: Thu, 19 Sep 2024 17:03:22 +0530
Subject: [PATCH] based on review comments

---
 zcash_test_vectors/orchard_zsa/digests.py |  2 +-
 zcash_test_vectors/transaction.py         |  3 ++-
 zcash_test_vectors/transaction_zsa.py     |  4 ++--
 zcash_test_vectors/zip_0244.py            | 29 ++++++++++-------------
 4 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/zcash_test_vectors/orchard_zsa/digests.py b/zcash_test_vectors/orchard_zsa/digests.py
index e488de6..6452b13 100755
--- a/zcash_test_vectors/orchard_zsa/digests.py
+++ b/zcash_test_vectors/orchard_zsa/digests.py
@@ -6,7 +6,7 @@
 
 NU7_VERSION_GROUP_ID = 0x124A69F8
 NU7_TX_VERSION = 6
-
+NU7_TX_VERSION_BYTES = NU7_TX_VERSION | (1 << 31)
 
 def orchard_zsa_burn_digest(tx):
     digest = blake2b(digest_size=32, person=b'ZTxIdOrcBurnHash')
diff --git a/zcash_test_vectors/transaction.py b/zcash_test_vectors/transaction.py
index 0ec4ff4..87b0801 100644
--- a/zcash_test_vectors/transaction.py
+++ b/zcash_test_vectors/transaction.py
@@ -25,6 +25,7 @@
 
 NU5_VERSION_GROUP_ID = 0x26A7270A
 NU5_TX_VERSION = 5
+NU5_TX_VERSION_BYTES = NU5_TX_VERSION | (1 << 31)
 
 # Sapling note magic values, copied from src/zcash/Zcash.h
 NOTEENCRYPTION_AUTH_BYTES = 16
@@ -561,7 +562,7 @@ def __init__(self, rand, consensus_branch_id):
 
     @staticmethod
     def version_bytes():
-        return NU5_TX_VERSION | (1 << 31)
+        return NU5_TX_VERSION_BYTES
 
     def __bytes__(self):
         ret = b''
diff --git a/zcash_test_vectors/transaction_zsa.py b/zcash_test_vectors/transaction_zsa.py
index 795bc42..0dde3a2 100644
--- a/zcash_test_vectors/transaction_zsa.py
+++ b/zcash_test_vectors/transaction_zsa.py
@@ -4,7 +4,7 @@
 from .orchard.key_components import FullViewingKey, SpendingKey
 from .orchard.pallas import Point
 from .orchard_zsa.key_components import IssuanceKeys
-from .orchard_zsa.digests import NU7_VERSION_GROUP_ID, NU7_TX_VERSION
+from .orchard_zsa.digests import NU7_VERSION_GROUP_ID, NU7_TX_VERSION_BYTES
 from .orchard_zsa.asset_base import zsa_value_base, asset_digest, encode_asset_id, get_random_unicode_bytes
 from .zc_utils import write_compact_size
 from .transaction import (
@@ -123,7 +123,7 @@ def __init__(self, rand, consensus_branch_id, have_orchard_zsa=True, have_burn=T
 
     @staticmethod
     def version_bytes():
-        return NU7_TX_VERSION | (1 << 31)
+        return NU7_TX_VERSION_BYTES
 
     def orchard_zsa_burn_field_bytes(self):
         ret = b''
diff --git a/zcash_test_vectors/zip_0244.py b/zcash_test_vectors/zip_0244.py
index 3961386..d20a3fb 100755
--- a/zcash_test_vectors/zip_0244.py
+++ b/zcash_test_vectors/zip_0244.py
@@ -4,14 +4,15 @@
 assert sys.version_info[0] >= 3, "Python 3 required."
 
 from hashlib import blake2b
+from collections import namedtuple
 import struct
 
-from .orchard_zsa.digests import NU7_TX_VERSION, orchard_zsa_burn_digest, issuance_digest, issuance_auth_digest
+from .orchard_zsa.digests import NU7_TX_VERSION_BYTES, orchard_zsa_burn_digest, issuance_digest, issuance_auth_digest
 from .transaction import (
     MAX_MONEY,
     Script,
     TransactionV5,
-    NU5_TX_VERSION,
+    NU5_TX_VERSION_BYTES,
 )
 from .output import render_args, render_tv
 from .rand import Rand
@@ -138,7 +139,7 @@ def orchard_digest(tx):
         digest.update(orchard_actions_compact_digest(tx))
         digest.update(orchard_actions_memos_digest(tx))
         digest.update(orchard_actions_noncompact_digest(tx))
-        if tx.version_bytes() == NU7_TX_VERSION | (1 << 31):
+        if tx.version_bytes() == NU7_TX_VERSION_BYTES:
             digest.update(orchard_zsa_burn_digest(tx))
         digest.update(struct.pack('<B', tx.flagsOrchard))
         digest.update(struct.pack('<Q', tx.valueBalanceOrchard))
@@ -158,19 +159,15 @@ def orchard_auth_digest(tx):
     return digest.digest()
 
 
-# - helpers for Actions functions
-class Offsets:
-    def __init__(self, compact_end, memo_end):
-        self.compact_end = compact_end
-        self.memo_end = memo_end
-
+# - helper for Actions functions
 def ciphertext_offset(tx_version_bytes):
-    if tx_version_bytes == NU5_TX_VERSION | (1 << 31):
+    Offsets = namedtuple('Offsets', ['compact_end', 'memo_end'])
+    if tx_version_bytes == NU5_TX_VERSION_BYTES:
         # Compact ends at 52, Memo ends at 564 for V5
-        return Offsets(52, 564)
-    elif tx_version_bytes == NU7_TX_VERSION | (1 << 31):
+        return Offsets(compact_end=52, memo_end=564)
+    elif tx_version_bytes == NU7_TX_VERSION_BYTES:
         # Compact ends at 84, Memo ends at 596 for V6
-        return Offsets(84, 596)
+        return Offsets(compact_end=84, memo_end=596)
     else:
         raise ValueError("Unsupported transaction version")
 
@@ -226,7 +223,7 @@ def txid_digest(tx):
     digest.update(transparent_digest(tx))
     digest.update(sapling_digest(tx))
     digest.update(orchard_digest(tx))
-    if tx.version_bytes() == NU7_TX_VERSION | (1 << 31):
+    if tx.version_bytes() == NU7_TX_VERSION_BYTES:
         digest.update(issuance_digest(tx))
 
     return digest.digest()
@@ -242,7 +239,7 @@ def auth_digest(tx):
     digest.update(transparent_scripts_digest(tx))
     digest.update(sapling_auth_digest(tx))
     digest.update(orchard_auth_digest(tx))
-    if tx.version_bytes() == NU7_TX_VERSION | (1 << 31):
+    if tx.version_bytes() == NU7_TX_VERSION_BYTES:
         digest.update(issuance_auth_digest(tx))
 
     return digest.digest()
@@ -265,7 +262,7 @@ def signature_digest(tx, t_inputs, nHashType, txin):
     digest.update(transparent_sig_digest(tx, t_inputs, nHashType, txin))
     digest.update(sapling_digest(tx))
     digest.update(orchard_digest(tx))
-    if tx.version_bytes() == NU7_TX_VERSION | (1 << 31):
+    if tx.version_bytes() == NU7_TX_VERSION_BYTES:
         digest.update(issuance_digest(tx))
 
     return digest.digest()