tlnpeer: check that remote only sends commit_sig if there are changes - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
DIR Refs
DIR Submodules
---
DIR commit 021f5d570ed8388f7d85f80172dfa7a6137600db
DIR parent dfc2a35ae6220b8dbabb090ab1064a61cf19ce35
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Tue, 26 Feb 2019 17:28:08 +0100
lnpeer: check that remote only sends commit_sig if there are changes
Diffstat:
M electrum/lnpeer.py | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
---
DIR diff --git a/electrum/lnpeer.py b/electrum/lnpeer.py
t@@ -36,7 +36,7 @@ from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc,
get_ln_flag_pair_of_bit, privkey_to_pubkey, UnknownPaymentHash, MIN_FINAL_CLTV_EXPIRY_ACCEPTED,
LightningPeerConnectionClosed, HandshakeFailed, NotFoundChanAnnouncementForUpdate,
MINIMUM_MAX_HTLC_VALUE_IN_FLIGHT_ACCEPTED, MAXIMUM_HTLC_MINIMUM_MSAT_ACCEPTED,
- MAXIMUM_REMOTE_TO_SELF_DELAY_ACCEPTED)
+ MAXIMUM_REMOTE_TO_SELF_DELAY_ACCEPTED, RemoteMisbehaving)
from .lntransport import LNTransport, LNTransportBase
from .lnmsg import encode_msg, decode_msg
t@@ -79,6 +79,7 @@ class Peer(PrintError):
self.attempted_route = {}
self.orphan_channel_updates = OrderedDict()
self.sent_commitment_for_ctn_last = defaultdict(lambda: None) # type: Dict[Channel, Optional[int]]
+ self.recv_commitment_for_ctn_last = defaultdict(lambda: None) # type: Dict[Channel, Optional[int]]
self._local_changed_events = defaultdict(asyncio.Event)
self._remote_changed_events = defaultdict(asyncio.Event)
t@@ -822,12 +823,13 @@ class Peer(PrintError):
def maybe_send_commitment(self, chan: Channel):
ctn_to_sign = chan.get_current_ctn(REMOTE) + 1
+ # if there are no changes, we will not (and must not) send a new commitment
pending, current = chan.hm.pending_htlcs(REMOTE), chan.hm.current_htlcs(REMOTE)
- if (pending == current \
+ if (pending == current
and chan.pending_feerate(REMOTE) == chan.constraints.feerate) \
or ctn_to_sign == self.sent_commitment_for_ctn_last[chan]:
return
- self.print_error('send_commitment. old number htlcs: {len(current)}, new number htlcs: {len(pending)}')
+ self.print_error(f'send_commitment. old number htlcs: {len(current)}, new number htlcs: {len(pending)}')
sig_64, htlc_sigs = chan.sign_next_commitment()
self.send_message("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=len(htlc_sigs), htlc_signature=b"".join(htlc_sigs))
self.sent_commitment_for_ctn_last[chan] = ctn_to_sign
t@@ -884,6 +886,14 @@ class Peer(PrintError):
self.print_error("on_commitment_signed")
channel_id = payload['channel_id']
chan = self.channels[channel_id]
+ ctn_to_recv = chan.get_current_ctn(LOCAL) + 1
+ # make sure there were changes to the ctx, otherwise the remote peer is misbehaving
+ if (chan.hm.pending_htlcs(LOCAL) == chan.hm.current_htlcs(LOCAL)
+ and chan.pending_feerate(LOCAL) == chan.constraints.feerate) \
+ or ctn_to_recv == self.recv_commitment_for_ctn_last[chan]:
+ raise RemoteMisbehaving('received commitment_signed without any change')
+ self.recv_commitment_for_ctn_last[chan] = ctn_to_recv
+
data = payload["htlc_signature"]
htlc_sigs = [data[i:i+64] for i in range(0, len(data), 64)]
chan.receive_new_commitment(payload["signature"], htlc_sigs)