tlnchan: only sign force_close_tx when demanded, assure consistency, fix test - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
DIR Refs
DIR Submodules
---
DIR commit 2323118bda08dcb62b98c7bf08beba35bf2324a9
DIR parent 37a0315aab8210e18665c1d8719e7b600c6797d4
HTML Author: Janus <ysangkok@gmail.com>
Date: Tue, 18 Dec 2018 14:35:22 +0100
lnchan: only sign force_close_tx when demanded, assure consistency, fix test
Diffstat:
M electrum/lnchan.py | 45 +++++++++++++++++++++-----------
M electrum/tests/test_lnchan.py | 42 ++++++++++++++++++++++++++++---
2 files changed, 69 insertions(+), 18 deletions(-)
---
DIR diff --git a/electrum/lnchan.py b/electrum/lnchan.py
t@@ -147,7 +147,7 @@ class Channel(PrintError):
except:
return super().diagnostic_name()
- def __init__(self, state, sweep_address = None, name = None, payment_completed : Optional[Callable[[HTLCOwner, UpdateAddHtlc, bytes], None]] = None):
+ def __init__(self, state, sweep_address = None, name = None, payment_completed : Optional[Callable[[HTLCOwner, UpdateAddHtlc, bytes], None]] = None, local_commitment = None):
self.preimages = {}
if not payment_completed:
payment_completed = lambda this, x, y, z: None
t@@ -205,7 +205,12 @@ class Channel(PrintError):
for sub in (LOCAL, REMOTE):
self.log[sub].locked_in.update(self.log[sub].adds.keys())
- self.set_local_commitment(self.current_commitment(LOCAL))
+ if local_commitment:
+ local_commitment = Transaction(str(local_commitment))
+ local_commitment.deserialize(True)
+ self.set_local_commitment(local_commitment)
+ else:
+ self.set_local_commitment(self.current_commitment(LOCAL))
self.set_remote_commitment(self.current_commitment(REMOTE))
def set_local_commitment(self, ctx):
t@@ -213,6 +218,8 @@ class Channel(PrintError):
if self.sweep_address is not None:
self.local_sweeptxs = create_sweeptxs_for_our_latest_ctx(self, self.local_commitment, self.sweep_address)
+ self.assert_signature_fits(ctx)
+
def set_remote_commitment(self, ctx):
self.remote_commitment = ctx
if self.sweep_address is not None:
t@@ -449,7 +456,9 @@ class Channel(PrintError):
feerate=new_feerate
)
- self.set_local_commitment(self.pending_commitment(LOCAL))
+ # since we should not revoke our latest commitment tx,
+ # we do not update self.local_commitment here,
+ # it should instead be updated when we receive a new sig
return RevokeAndAck(last_secret, next_point), "current htlcs"
t@@ -541,7 +550,6 @@ class Channel(PrintError):
if self.constraints.is_initiator:
self.pending_fee[FUNDEE_ACKED] = True
- self.set_local_commitment(self.pending_commitment(LOCAL))
self.set_remote_commitment(self.pending_commitment(REMOTE))
self.remote_commitment_to_be_revoked = prev_remote_commitment
return received_this_batch, sent_this_batch
t@@ -773,7 +781,7 @@ class Channel(PrintError):
serialized_channel[k] = v
dumped = ChannelJsonEncoder().encode(serialized_channel)
roundtripped = json.loads(dumped)
- reconstructed = Channel(roundtripped)
+ reconstructed = Channel(roundtripped, local_commitment=self.local_commitment)
to_save_new = reconstructed.to_save()
if to_save_new != to_save_ref:
from pprint import PrettyPrinter
t@@ -864,19 +872,26 @@ class Channel(PrintError):
sig = ecc.sig_string_from_der_sig(der_sig[:-1])
return sig, closing_tx
+ def assert_signature_fits(self, tx):
+ remote_sig = self.config[LOCAL].current_commitment_signature
+ if remote_sig: # only None in test
+ preimage_hex = tx.serialize_preimage(0)
+ pre_hash = sha256d(bfh(preimage_hex))
+ assert ecc.verify_signature(self.config[REMOTE].multisig_key.pubkey, remote_sig, pre_hash)
+
def force_close_tx(self):
- tx = self.current_commitment(LOCAL)
+ tx = self.local_commitment
+ tx = Transaction(str(tx))
+ tx.deserialize(True)
+ self.assert_signature_fits(tx)
tx.sign({bh2u(self.config[LOCAL].multisig_key.pubkey): (self.config[LOCAL].multisig_key.privkey, True)})
remote_sig = self.config[LOCAL].current_commitment_signature
-
- preimage_hex = tx.serialize_preimage(0)
- pre_hash = sha256d(bfh(preimage_hex))
- assert ecc.verify_signature(self.config[REMOTE].multisig_key.pubkey, remote_sig, pre_hash)
-
- remote_sig = ecc.der_sig_from_sig_string(remote_sig) + b"\x01"
- none_idx = tx._inputs[0]["signatures"].index(None)
- tx.add_signature_to_txin(0, none_idx, bh2u(remote_sig))
- assert tx.is_complete()
+ if remote_sig: # only None in test
+ remote_sig = ecc.der_sig_from_sig_string(remote_sig) + b"\x01"
+ sigs = tx._inputs[0]["signatures"]
+ none_idx = sigs.index(None)
+ tx.add_signature_to_txin(0, none_idx, bh2u(remote_sig))
+ assert tx.is_complete()
return tx
def included_htlcs_in_their_latest_ctxs(self, htlc_initiator) -> Dict[int, List[UpdateAddHtlc]]:
DIR diff --git a/electrum/tests/test_lnchan.py b/electrum/tests/test_lnchan.py
t@@ -83,7 +83,7 @@ def create_channel_state(funding_txid, funding_index, funding_sat, local_feerate
funding_locked_received=True,
was_announced=False,
# just a random signature
- current_commitment_signature=sig_string_from_der_sig(bytes.fromhex('3046022100c66e112e22b91b96b795a6dd5f4b004f3acccd9a2a31bf104840f256855b7aa3022100e711b868b62d87c7edd95a2370e496b9cb6a38aff13c9f64f9ff2f3b2a0052dd')),
+ current_commitment_signature=None,
current_htlc_signatures=None,
),
"constraints":lnbase.ChannelConstraints(
t@@ -134,6 +134,20 @@ def create_test_channels(feerate=6000, local=None, remote=None):
alice.set_state('OPEN')
bob.set_state('OPEN')
+
+ #old_bob = bob.config[REMOTE]
+ #bob.config[REMOTE] = bob.config[REMOTE]._replace(ctn=bob.config[REMOTE].ctn)
+ #sig_from_bob = bob.sign_next_commitment()[0]
+ #bob.config[REMOTE] = old_bob
+
+ #old_alice = alice.config[REMOTE]
+ #alice.config[REMOTE] = alice.config[REMOTE]._replace(ctn=alice.config[REMOTE].ctn)
+ #sig_from_alice = alice.sign_next_commitment()[0]
+ #alice.config[REMOTE] = old_alice
+
+ #alice.config[LOCAL] = alice.config[LOCAL]._replace(current_commitment_signature=sig_from_bob)
+ #bob.config[LOCAL] = bob.config[LOCAL]._replace(current_commitment_signature=sig_from_alice)
+
return alice, bob
class TestFee(unittest.TestCase):
t@@ -204,6 +218,9 @@ class TestChannel(unittest.TestCase):
self.assertEqual({0: [], 1: []}, alice_channel.included_htlcs_in_their_latest_ctxs(REMOTE))
self.assertEqual({0: [], 1: []}, bob_channel.included_htlcs_in_their_latest_ctxs(LOCAL))
+ # this wouldn't work since we put None in the remote_sig
+ # alice_channel.force_close_tx()
+
# Next alice commits this change by sending a signature message. Since
# we expect the messages to be ordered, Bob will receive the HTLC we
# just sent before he receives this signature, so the signature will
t@@ -237,8 +254,6 @@ class TestChannel(unittest.TestCase):
# forward since she's sending an outgoing HTLC.
alice_channel.receive_revocation(bobRevocation)
- alice_channel.force_close_tx()
-
# test serializing with locked_in htlc
self.assertEqual(len(alice_channel.to_save()['local_log']), 1)
alice_channel.serialize()
t@@ -248,9 +263,15 @@ class TestChannel(unittest.TestCase):
# the point where she sent her signature, including the HTLC.
alice_channel.receive_new_commitment(bobSig, bobHtlcSigs)
+ tx1 = str(alice_channel.force_close_tx())
+
# Alice then generates a revocation for bob.
aliceRevocation, _ = alice_channel.revoke_current_commitment()
+ tx2 = str(alice_channel.force_close_tx())
+ # since alice already has the signature for the next one, it doesn't change her force close tx (it was already the newer one)
+ self.assertEqual(tx1, tx2)
+
# Finally Bob processes Alice's revocation, at this point the new HTLC
# is fully locked in within both commitment transactions. Bob should
# also be able to forward an HTLC now that the HTLC has been locked
t@@ -284,6 +305,10 @@ class TestChannel(unittest.TestCase):
alice_channel.receive_htlc_settle(preimage, self.aliceHtlcIndex)
+ tx3 = str(alice_channel.force_close_tx())
+ # just settling a htlc does not change her force close tx
+ self.assertEqual(tx2, tx3)
+
bobSig2, bobHtlcSigs2 = bob_channel.sign_next_commitment()
self.assertEqual({1: [htlc], 2: []}, alice_channel.included_htlcs_in_their_latest_ctxs(LOCAL))
t@@ -293,6 +318,9 @@ class TestChannel(unittest.TestCase):
alice_channel.receive_new_commitment(bobSig2, bobHtlcSigs2)
+ tx4 = str(alice_channel.force_close_tx())
+ self.assertNotEqual(tx3, tx4)
+
aliceRevocation2, _ = alice_channel.revoke_current_commitment()
aliceSig2, aliceHtlcSigs2 = alice_channel.sign_next_commitment()
self.assertEqual(aliceHtlcSigs2, [], "alice should generate no htlc signatures")
t@@ -326,8 +354,16 @@ class TestChannel(unittest.TestCase):
alice_channel.update_fee(100000, True)
bob_channel.update_fee(100000, False)
+
+ tx5 = str(alice_channel.force_close_tx())
+ # sending a fee update does not change her force close tx
+ self.assertEqual(tx4, tx5)
+
force_state_transition(alice_channel, bob_channel)
+ tx6 = str(alice_channel.force_close_tx())
+ self.assertNotEqual(tx5, tx6)
+
self.htlc_dict['amount_msat'] *= 5
bob_index = bob_channel.add_htlc(self.htlc_dict)
alice_index = alice_channel.receive_htlc(self.htlc_dict)