From 7e2aa8088be83ee671478cfc31dc28c3b15d5ee6 Mon Sep 17 00:00:00 2001
From: The MMGen Project <mmgen@tuta.io>
Date: Wed, 9 Sep 2026 18:33:59 +0000
Subject: [PATCH] transaction versioning

Transaction versioning provides a mechanism to require the user to keep
online and offline installations in sync.
---
 mmgen/tx/completed.py      | 15 +++++++++++++++
 mmgen/tx/file.py           |  8 ++++++--
 test/cmdtest_d/autosign.py |  9 ++++++---
 test/modtest_d/tx.py       |  8 +++++++-
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/mmgen/tx/completed.py b/mmgen/tx/completed.py
index 0c6a1127..38949260 100755
--- a/mmgen/tx/completed.py
+++ b/mmgen/tx/completed.py
@@ -21,6 +21,7 @@ class Completed(Base):
 	signed or unsigned transaction with associated file
 	"""
 	filename_api = True
+	txfile_version = 4
 
 	def __init__(self, cfg, *args, filename=None, data=None, quiet_open=False, **kwargs):
 
@@ -116,6 +117,20 @@ class Completed(Base):
 		fs = f'Request to {{}} legacy-format transaction ({desc}). {{}}'
 		self.die_on_version_error(fs.format(a, b))
 
+	def txfile_version_chk(self, f_ver, s_ver):
+		if 'sign' in gc.prog_name:
+			a = 'sign'
+			b = 'Is your {} installation out of date?'.format('offline' if f_ver > s_ver else 'online')
+		elif 'send' in gc.prog_name:
+			a = 'send'
+			b = 'Is your {} installation out of date?'.format('offline' if f_ver < s_ver else 'online')
+		else:
+			return
+		fs = (
+			f'Request to {{}} transaction with version {f_ver}, which is {{}} '
+			f'than version {s_ver} current with installed software. {{}}')
+		self.die_on_version_error(fs.format(a, ('greater' if f_ver > s_ver else 'less'), b))
+
 class DummyCompleted: # required by MMGenTxFile.get_proto()
 
 	desc = 'dummy transaction'
diff --git a/mmgen/tx/file.py b/mmgen/tx/file.py
index 8e8421c1..d4722e1d 100755
--- a/mmgen/tx/file.py
+++ b/mmgen/tx/file.py
@@ -94,7 +94,7 @@ class MMGenTxFile(MMGenObject):
 		tx = self.tx
 		tx.file_format = 'json'
 		outer_data = json.loads(data)
-		if 'MoneroMMGenTX' in outer_data:
+		if 'MoneroMMGenTX' in outer_data: # txfile_version_chk for Monero TBD
 			tx.proto = get_monero_proto(tx, outer_data)
 			return None
 		data = outer_data[self.data_label]
@@ -107,6 +107,9 @@ class MMGenTxFile(MMGenObject):
 		if get_proto_only:
 			return
 
+		if data.get('version', 0) != tx.txfile_version:
+			tx.txfile_version_chk(data.get('version', 0), tx.txfile_version)
+
 		for k, v in self.attrs.items():
 			if v != 'skip':
 				setattr(tx, k, v(data[k]) if v else data[k])
@@ -278,7 +281,8 @@ class MMGenTxFile(MMGenObject):
 
 		def format_data_json():
 			data = txfile_json_dumps({
-					'coin_id': coin_id
+					'coin_id': coin_id,
+					'version': tx.txfile_version
 				} | {
 					k: getattr(tx, k) for k in self.attrs
 				} | {
diff --git a/test/cmdtest_d/autosign.py b/test/cmdtest_d/autosign.py
index 990c5ded..c1a0b2bd 100755
--- a/test/cmdtest_d/autosign.py
+++ b/test/cmdtest_d/autosign.py
@@ -909,7 +909,7 @@ class CmdTestAutosign(CmdTestAutosignBase):
 		self.remove_device()
 		return 'ok'
 
-	def do_sign(self, args=[], have_msg=False, exc_exit_val=None, expect_str=None):
+	def do_sign(self, args=[], have_msg=False, exc_exit_val=None, expect_str=None, bad_version=False):
 
 		tx_desc = Signable.transaction.desc
 		self.insert_device()
@@ -930,6 +930,9 @@ class CmdTestAutosign(CmdTestAutosignBase):
 		if exc_exit_val:
 			return do_return()
 
+		if bad_version:
+			t.expect('out of date')
+
 		t.expect('legacy-format')
 
 		t.expect(
@@ -953,10 +956,10 @@ class CmdTestAutosign(CmdTestAutosignBase):
 		return do_return()
 
 	def sign_quiet(self):
-		return self.do_sign(['--quiet'])
+		return self.do_sign(['--quiet'], bad_version=True)
 
 	def sign_full_summary(self):
-		return self.do_sign(['--full-summary'])
+		return self.do_sign(['--full-summary'], bad_version=True)
 
 	def sign_led(self):
 		return self.do_sign(['--quiet', '--led'])
diff --git a/test/modtest_d/tx.py b/test/modtest_d/tx.py
index 6766a0ed..a5398907 100755
--- a/test/modtest_d/tx.py
+++ b/test/modtest_d/tx.py
@@ -45,7 +45,13 @@ async def do_txfile_test(desc, fns, cfg=cfg, do_format=True):
 			ref_text = txfile_json_dumps(ref_data)
 
 			# process newly-formatted data:
-			new_text = f.format()
+			if 'version' in ref_data:
+				new_text = f.format()
+			else:
+				new_data = json.loads(f.format())
+				del new_data['MMGenTransaction']['version']
+				new_data['chksum'] = make_chksum_6(txfile_json_dumps(new_data['MMGenTransaction']))
+				new_text = txfile_json_dumps(new_data)
 
 			assert new_text == ref_text, f'\nformatted text:\n{new_text}\n  !=\noriginal file:\n{ref_text}'