Merge pull request #391 from ariard/2019-11-fix-preimage-collision-onchain

Avoid claiming remote received HTLCs with side-learned preimage
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Matt Corallo 2019-11-15 19:20:43 +00:00 committed by GitHub
commit a30946b292
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2 changed files with 107 additions and 38 deletions

View file

@ -1643,46 +1643,48 @@ impl ChannelMonitor {
return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user
}
if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
let input = TxIn {
previous_output: BitcoinOutPoint {
txid: commitment_txid,
vout: transaction_output_index,
},
script_sig: Script::new(),
sequence: idx as u32, // reset to 0xfffffffd in sign_input
witness: Vec::new(),
};
if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
inputs.push(input);
inputs_desc.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value, htlc.cltv_expiry));
total_value += tx.output[transaction_output_index as usize].value;
} else {
let mut single_htlc_tx = Transaction {
version: 2,
lock_time: 0,
input: vec![input],
output: vec!(TxOut {
script_pubkey: self.destination_script.clone(),
value: htlc.amount_msat / 1000,
}),
if htlc.offered {
let input = TxIn {
previous_output: BitcoinOutPoint {
txid: commitment_txid,
vout: transaction_output_index,
},
script_sig: Script::new(),
sequence: idx as u32, // reset to 0xfffffffd in sign_input
witness: Vec::new(),
};
let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }]);
let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
let mut used_feerate;
if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
let (redeemscript, htlc_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
assert!(predicted_weight >= single_htlc_tx.get_weight());
spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
output: single_htlc_tx.output[0].clone(),
});
match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
hash_map::Entry::Occupied(_) => {},
hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
inputs.push(input);
inputs_desc.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value, htlc.cltv_expiry));
total_value += tx.output[transaction_output_index as usize].value;
} else {
let mut single_htlc_tx = Transaction {
version: 2,
lock_time: 0,
input: vec![input],
output: vec!(TxOut {
script_pubkey: self.destination_script.clone(),
value: htlc.amount_msat / 1000,
}),
};
let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }]);
let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
let mut used_feerate;
if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
let (redeemscript, htlc_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
assert!(predicted_weight >= single_htlc_tx.get_weight());
spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
output: single_htlc_tx.output[0].clone(),
});
match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
hash_map::Entry::Occupied(_) => {},
hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
}
txn_to_broadcast.push(single_htlc_tx);
}
txn_to_broadcast.push(single_htlc_tx);
}
}
}

View file

@ -1245,6 +1245,73 @@ fn duplicate_htlc_test() {
claim_payment(&nodes[1], &vec!(&nodes[3])[..], payment_preimage);
}
#[test]
fn test_duplicate_htlc_different_direction_onchain() {
// Test that ChannelMonitor doesn't generate 2 preimage txn
// when we have 2 HTLCs with same preimage that go across a node
// in opposite directions.
let nodes = create_network(2, &[None, None]);
let chan_1 = create_announced_chan_between_nodes(&nodes, 0, 1, LocalFeatures::new(), LocalFeatures::new());
// balancing
send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000);
let (payment_preimage, payment_hash) = route_payment(&nodes[0], &vec!(&nodes[1])[..], 900_000);
let route = nodes[1].router.get_route(&nodes[0].node.get_our_node_id(), None, &Vec::new(), 800_000, TEST_FINAL_CLTV).unwrap();
send_along_route_with_hash(&nodes[1], route, &vec!(&nodes[0])[..], 800_000, payment_hash);
// Provide preimage to node 0 by claiming payment
nodes[0].node.claim_funds(payment_preimage);
check_added_monitors!(nodes[0], 1);
// Broadcast node 1 commitment txn
let remote_txn = nodes[1].node.channel_state.lock().unwrap().by_id.get(&chan_1.2).unwrap().last_local_commitment_txn.clone();
assert_eq!(remote_txn[0].output.len(), 4); // 1 local, 1 remote, 1 htlc inbound, 1 htlc outbound
let mut has_both_htlcs = 0; // check htlcs match ones committed
for outp in remote_txn[0].output.iter() {
if outp.value == 800_000 / 1000 {
has_both_htlcs += 1;
} else if outp.value == 900_000 / 1000 {
has_both_htlcs += 1;
}
}
assert_eq!(has_both_htlcs, 2);
let header = BlockHeader { version: 0x2000_0000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
nodes[0].chain_monitor.block_connected_with_filtering(&Block { header, txdata: vec![remote_txn[0].clone()] }, 1);
// Check we only broadcast 1 timeout tx
let claim_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().clone();
let htlc_pair = if claim_txn[0].output[0].value == 800_000 / 1000 { (claim_txn[0].clone(), claim_txn[1].clone()) } else { (claim_txn[1].clone(), claim_txn[0].clone()) };
assert_eq!(claim_txn.len(), 6);
assert_eq!(htlc_pair.0.input.len(), 1);
assert_eq!(htlc_pair.0.input[0].witness.last().unwrap().len(), OFFERED_HTLC_SCRIPT_WEIGHT); // HTLC 1 <--> 0, preimage tx
check_spends!(htlc_pair.0, remote_txn[0].clone());
assert_eq!(htlc_pair.1.input.len(), 1);
assert_eq!(htlc_pair.1.input[0].witness.last().unwrap().len(), ACCEPTED_HTLC_SCRIPT_WEIGHT); // HTLC 0 <--> 1, timeout tx
check_spends!(htlc_pair.1, remote_txn[0].clone());
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 2);
for e in events {
match e {
MessageSendEvent::BroadcastChannelUpdate { .. } => {},
MessageSendEvent::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, .. } } => {
assert!(update_add_htlcs.is_empty());
assert!(update_fail_htlcs.is_empty());
assert_eq!(update_fulfill_htlcs.len(), 1);
assert!(update_fail_malformed_htlcs.is_empty());
assert_eq!(nodes[1].node.get_our_node_id(), *node_id);
},
_ => panic!("Unexpected event"),
}
}
}
fn do_channel_reserve_test(test_recv: bool) {
use ln::msgs::HandleError;