]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Add test for aggregated revoked HTLC claim on anchors channel
authorWilmer Paulino <wilmer@wilmerpaulino.com>
Wed, 15 Feb 2023 00:10:52 +0000 (16:10 -0800)
committerWilmer Paulino <wilmer@wilmerpaulino.com>
Mon, 20 Mar 2023 18:32:15 +0000 (11:32 -0700)
lightning/src/ln/functional_test_utils.rs
lightning/src/ln/monitor_tests.rs

index f48c9d099e7e3eb3b03d4cf5f92cfca1d37f4b4b..51ad65949ef437fca0b0fc2057a072054cf96c92 100644 (file)
@@ -1239,24 +1239,23 @@ macro_rules! check_warn_msg {
 
 /// Check that a channel's closing channel update has been broadcasted, and optionally
 /// check whether an error message event has occurred.
-pub fn check_closed_broadcast(node: &Node, with_error_msg: bool) -> Option<msgs::ErrorMessage> {
+pub fn check_closed_broadcast(node: &Node, num_channels: usize, with_error_msg: bool) -> Vec<msgs::ErrorMessage> {
        let msg_events = node.node.get_and_clear_pending_msg_events();
-       assert_eq!(msg_events.len(), if with_error_msg { 2 } else { 1 });
-       match msg_events[0] {
-               MessageSendEvent::BroadcastChannelUpdate { ref msg } => {
-                       assert_eq!(msg.contents.flags & 2, 2);
-               },
-               _ => panic!("Unexpected event"),
-       }
-       if with_error_msg {
-               match msg_events[1] {
+       assert_eq!(msg_events.len(), if with_error_msg { num_channels * 2 } else { num_channels });
+       msg_events.into_iter().filter_map(|msg_event| {
+               match msg_event {
+                       MessageSendEvent::BroadcastChannelUpdate { ref msg } => {
+                               assert_eq!(msg.contents.flags & 2, 2);
+                               None
+                       },
                        MessageSendEvent::HandleError { action: msgs::ErrorAction::SendErrorMessage { ref msg }, node_id: _ } => {
+                               assert!(with_error_msg);
                                // TODO: Check node_id
                                Some(msg.clone())
                        },
                        _ => panic!("Unexpected event"),
                }
-       } else { None }
+       }).collect()
 }
 
 /// Check that a channel's closing channel update has been broadcasted, and optionally
@@ -1266,7 +1265,7 @@ pub fn check_closed_broadcast(node: &Node, with_error_msg: bool) -> Option<msgs:
 #[macro_export]
 macro_rules! check_closed_broadcast {
        ($node: expr, $with_error_msg: expr) => {
-               $crate::ln::functional_test_utils::check_closed_broadcast(&$node, $with_error_msg)
+               $crate::ln::functional_test_utils::check_closed_broadcast(&$node, 1, $with_error_msg).pop()
        }
 }
 
index af33ca7b737db3352fe04aebbb548b5f15e0835d..3bd50293ff24aa2bdf36f1935590d8341213cbca 100644 (file)
@@ -19,20 +19,34 @@ use crate::chain::chaininterface::LowerBoundedFeeEstimator;
 use crate::ln::channel;
 #[cfg(anchors)]
 use crate::ln::chan_utils;
+#[cfg(anchors)]
+use crate::ln::channelmanager::ChannelManager;
 use crate::ln::channelmanager::{BREAKDOWN_TIMEOUT, PaymentId};
 use crate::ln::msgs::ChannelMessageHandler;
 #[cfg(anchors)]
 use crate::util::config::UserConfig;
 #[cfg(anchors)]
+use crate::util::crypto::sign;
+#[cfg(anchors)]
 use crate::util::events::BumpTransactionEvent;
 use crate::util::events::{Event, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
+#[cfg(anchors)]
+use crate::util::ser::Writeable;
+#[cfg(anchors)]
+use crate::util::test_utils;
 
+#[cfg(anchors)]
+use bitcoin::blockdata::transaction::EcdsaSighashType;
 use bitcoin::blockdata::script::Builder;
 use bitcoin::blockdata::opcodes;
 use bitcoin::secp256k1::Secp256k1;
 #[cfg(anchors)]
-use bitcoin::{Amount, Script, TxIn, TxOut, PackedLockTime};
+use bitcoin::secp256k1::SecretKey;
+#[cfg(anchors)]
+use bitcoin::{Amount, PublicKey, Script, TxIn, TxOut, PackedLockTime, Witness};
 use bitcoin::Transaction;
+#[cfg(anchors)]
+use bitcoin::util::sighash::SighashCache;
 
 use crate::prelude::*;
 
@@ -1748,7 +1762,7 @@ fn test_yield_anchors_events() {
 
        let mut holder_events = nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events();
        // Certain block `ConnectStyle`s cause an extra `ChannelClose` event to be emitted since the
-       // best block is being updated prior to the confirmed transactions.
+       // best block is updated before the confirmed transactions are notified.
        match *nodes[0].connect_style.borrow() {
                ConnectStyle::BestBlockFirst|ConnectStyle::BestBlockFirstReorgsOnlyTip|ConnectStyle::BestBlockFirstSkippingBlocks => {
                        assert_eq!(holder_events.len(), 3);
@@ -1815,3 +1829,358 @@ fn test_yield_anchors_events() {
        // Clear the remaining events as they're not relevant to what we're testing.
        nodes[0].node.get_and_clear_pending_events();
 }
+
+#[cfg(anchors)]
+#[test]
+fn test_anchors_aggregated_revoked_htlc_tx() {
+       // Test that `ChannelMonitor`s can properly detect and claim funds from a counterparty claiming
+       // multiple HTLCs from multiple channels in a single transaction via the success path from a
+       // revoked commitment.
+       let secp = Secp256k1::new();
+       let mut chanmon_cfgs = create_chanmon_cfgs(2);
+       // Required to sign a revoked commitment transaction
+       chanmon_cfgs[1].keys_manager.disable_revocation_policy_check = true;
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let mut anchors_config = UserConfig::default();
+       anchors_config.channel_handshake_config.announced_channel = true;
+       anchors_config.channel_handshake_config.negotiate_anchors_zero_fee_htlc_tx = true;
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[Some(anchors_config), Some(anchors_config)]);
+
+       let bob_persister: test_utils::TestPersister;
+       let bob_chain_monitor: test_utils::TestChainMonitor;
+       let bob_deserialized: ChannelManager<
+               &test_utils::TestChainMonitor, &test_utils::TestBroadcaster, &test_utils::TestKeysInterface,
+               &test_utils::TestKeysInterface, &test_utils::TestKeysInterface, &test_utils::TestFeeEstimator,
+               &test_utils::TestRouter, &test_utils::TestLogger,
+       >;
+
+       let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let chan_a = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 20_000_000);
+       let chan_b = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 20_000_000);
+
+       // Route two payments for each channel from Alice to Bob to lock in the HTLCs.
+       let payment_a = route_payment(&nodes[0], &[&nodes[1]], 50_000_000);
+       let payment_b = route_payment(&nodes[0], &[&nodes[1]], 50_000_000);
+       let payment_c = route_payment(&nodes[0], &[&nodes[1]], 50_000_000);
+       let payment_d = route_payment(&nodes[0], &[&nodes[1]], 50_000_000);
+
+       // Serialize Bob with the HTLCs locked in. We'll restart Bob later on with the state at this
+       // point such that he broadcasts a revoked commitment transaction.
+       let bob_serialized = nodes[1].node.encode();
+       let bob_serialized_monitor_a = get_monitor!(nodes[1], chan_a.2).encode();
+       let bob_serialized_monitor_b = get_monitor!(nodes[1], chan_b.2).encode();
+
+       // Bob claims all the HTLCs...
+       claim_payment(&nodes[0], &[&nodes[1]], payment_a.0);
+       claim_payment(&nodes[0], &[&nodes[1]], payment_b.0);
+       claim_payment(&nodes[0], &[&nodes[1]], payment_c.0);
+       claim_payment(&nodes[0], &[&nodes[1]], payment_d.0);
+
+       // ...and sends one back through each channel such that he has a motive to broadcast his
+       // revoked state.
+       send_payment(&nodes[1], &[&nodes[0]], 30_000_000);
+       send_payment(&nodes[1], &[&nodes[0]], 30_000_000);
+
+       // Restart Bob with the revoked state and provide the HTLC preimages he claimed.
+       reload_node!(
+               nodes[1], anchors_config, bob_serialized, &[&bob_serialized_monitor_a, &bob_serialized_monitor_b],
+               bob_persister, bob_chain_monitor, bob_deserialized
+       );
+       for chan_id in [chan_a.2, chan_b.2].iter() {
+               let monitor = get_monitor!(nodes[1], chan_id);
+               for payment in [payment_a, payment_b, payment_c, payment_d].iter() {
+                       monitor.provide_payment_preimage(
+                               &payment.1, &payment.0, &node_cfgs[1].tx_broadcaster,
+                               &LowerBoundedFeeEstimator::new(node_cfgs[1].fee_estimator), &nodes[1].logger
+                       );
+               }
+       }
+
+       // Bob force closes by broadcasting his revoked state for each channel.
+       nodes[1].node.force_close_broadcasting_latest_txn(&chan_a.2, &nodes[0].node.get_our_node_id()).unwrap();
+       check_added_monitors(&nodes[1], 1);
+       check_closed_broadcast(&nodes[1], 1, true);
+       check_closed_event!(&nodes[1], 1, ClosureReason::HolderForceClosed);
+       let revoked_commitment_a = {
+               let mut txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+               assert_eq!(txn.len(), 1);
+               let revoked_commitment = txn.pop().unwrap();
+               assert_eq!(revoked_commitment.output.len(), 6); // 2 HTLC outputs + 1 to_self output + 1 to_remote output + 2 anchor outputs
+               check_spends!(revoked_commitment, chan_a.3);
+               revoked_commitment
+       };
+       nodes[1].node.force_close_broadcasting_latest_txn(&chan_b.2, &nodes[0].node.get_our_node_id()).unwrap();
+       check_added_monitors(&nodes[1], 1);
+       check_closed_broadcast(&nodes[1], 1, true);
+       check_closed_event!(&nodes[1], 1, ClosureReason::HolderForceClosed);
+       let revoked_commitment_b = {
+               let mut txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+               assert_eq!(txn.len(), 1);
+               let revoked_commitment = txn.pop().unwrap();
+               assert_eq!(revoked_commitment.output.len(), 6); // 2 HTLC outputs + 1 to_self output + 1 to_remote output + 2 anchor outputs
+               check_spends!(revoked_commitment, chan_b.3);
+               revoked_commitment
+       };
+
+       // Bob should now receive two events to bump his revoked commitment transaction fees.
+       assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+       let events = nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events();
+       assert_eq!(events.len(), 2);
+       let anchor_tx = {
+               let secret_key = SecretKey::from_slice(&[1; 32]).unwrap();
+               let public_key = PublicKey::new(secret_key.public_key(&secp));
+               let fee_utxo_script = Script::new_v0_p2wpkh(&public_key.wpubkey_hash().unwrap());
+               let coinbase_tx = Transaction {
+                       version: 2,
+                       lock_time: PackedLockTime::ZERO,
+                       input: vec![TxIn { ..Default::default() }],
+                       output: vec![TxOut { // UTXO to attach fees to `anchor_tx`
+                               value: Amount::ONE_BTC.to_sat(),
+                               script_pubkey: fee_utxo_script.clone(),
+                       }],
+               };
+               let mut anchor_tx = Transaction {
+                       version: 2,
+                       lock_time: PackedLockTime::ZERO,
+                       input: vec![
+                               TxIn { // Fee input
+                                       previous_output: bitcoin::OutPoint { txid: coinbase_tx.txid(), vout: 0 },
+                                       ..Default::default()
+                               },
+                       ],
+                       output: vec![TxOut { // Fee input change
+                               value: coinbase_tx.output[0].value / 2 ,
+                               script_pubkey: Script::new_op_return(&[]),
+                       }],
+               };
+               let mut signers = Vec::with_capacity(2);
+               for event in events {
+                       match event {
+                               Event::BumpTransaction(BumpTransactionEvent::ChannelClose { anchor_descriptor, .. })  => {
+                                       anchor_tx.input.push(TxIn {
+                                               previous_output: anchor_descriptor.outpoint,
+                                               ..Default::default()
+                                       });
+                                       let signer = nodes[1].keys_manager.derive_channel_keys(
+                                               anchor_descriptor.channel_value_satoshis, &anchor_descriptor.channel_keys_id,
+                                       );
+                                       signers.push(signer);
+                               },
+                               _ => panic!("Unexpected event"),
+                       }
+               }
+               for (i, signer) in signers.into_iter().enumerate() {
+                       let anchor_idx = i + 1;
+                       let funding_sig = signer.sign_holder_anchor_input(&mut anchor_tx, anchor_idx, &secp).unwrap();
+                       anchor_tx.input[anchor_idx].witness = chan_utils::build_anchor_input_witness(
+                               &signer.pubkeys().funding_pubkey, &funding_sig
+                       );
+               }
+               let fee_utxo_sig = {
+                       let witness_script = Script::new_p2pkh(&public_key.pubkey_hash());
+                       let sighash = hash_to_message!(&SighashCache::new(&anchor_tx).segwit_signature_hash(
+                               0, &witness_script, coinbase_tx.output[0].value, EcdsaSighashType::All
+                       ).unwrap()[..]);
+                       let sig = sign(&secp, &sighash, &secret_key);
+                       let mut sig = sig.serialize_der().to_vec();
+                       sig.push(EcdsaSighashType::All as u8);
+                       sig
+               };
+               anchor_tx.input[0].witness = Witness::from_vec(vec![fee_utxo_sig, public_key.to_bytes()]);
+               check_spends!(anchor_tx, coinbase_tx, revoked_commitment_a, revoked_commitment_b);
+               anchor_tx
+       };
+
+       for node in &nodes {
+               mine_transactions(node, &[&revoked_commitment_a, &revoked_commitment_b, &anchor_tx]);
+       }
+       check_added_monitors!(&nodes[0], 2);
+       check_closed_broadcast(&nodes[0], 2, true);
+       check_closed_event!(&nodes[0], 2, ClosureReason::CommitmentTxConfirmed);
+
+       // Alice should detect the confirmed revoked commitments, and attempt to claim all of the
+       // revoked outputs.
+       {
+               let txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+               assert_eq!(txn.len(), 2);
+
+               let (revoked_claim_a, revoked_claim_b) = if txn[0].input[0].previous_output.txid == revoked_commitment_a.txid() {
+                       (&txn[0], &txn[1])
+               } else {
+                       (&txn[1], &txn[0])
+               };
+
+               // TODO: to_self claim must be separate from HTLC claims
+               assert_eq!(revoked_claim_a.input.len(), 3); // Spends both HTLC outputs and to_self output
+               assert_eq!(revoked_claim_a.output.len(), 1);
+               check_spends!(revoked_claim_a, revoked_commitment_a);
+               assert_eq!(revoked_claim_b.input.len(), 3); // Spends both HTLC outputs and to_self output
+               assert_eq!(revoked_claim_b.output.len(), 1);
+               check_spends!(revoked_claim_b, revoked_commitment_b);
+       }
+
+       // Since Bob was able to confirm his revoked commitment, he'll now try to claim the HTLCs
+       // through the success path.
+       assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+       let mut events = nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events();
+       // Certain block `ConnectStyle`s cause an extra `ChannelClose` event to be emitted since the
+       // best block is updated before the confirmed transactions are notified.
+       match *nodes[1].connect_style.borrow() {
+               ConnectStyle::BestBlockFirst|ConnectStyle::BestBlockFirstReorgsOnlyTip|ConnectStyle::BestBlockFirstSkippingBlocks => {
+                       assert_eq!(events.len(), 4);
+                       if let Event::BumpTransaction(BumpTransactionEvent::ChannelClose { .. }) = events.remove(0) {}
+                       else { panic!("unexpected event"); }
+                       if let Event::BumpTransaction(BumpTransactionEvent::ChannelClose { .. }) = events.remove(1) {}
+                       else { panic!("unexpected event"); }
+
+               },
+               _ => assert_eq!(events.len(), 2),
+       };
+       let htlc_tx = {
+               let secret_key = SecretKey::from_slice(&[1; 32]).unwrap();
+               let public_key = PublicKey::new(secret_key.public_key(&secp));
+               let fee_utxo_script = Script::new_v0_p2wpkh(&public_key.wpubkey_hash().unwrap());
+               let coinbase_tx = Transaction {
+                       version: 2,
+                       lock_time: PackedLockTime::ZERO,
+                       input: vec![TxIn { ..Default::default() }],
+                       output: vec![TxOut { // UTXO to attach fees to `htlc_tx`
+                               value: Amount::ONE_BTC.to_sat(),
+                               script_pubkey: fee_utxo_script.clone(),
+                       }],
+               };
+               let mut htlc_tx = Transaction {
+                       version: 2,
+                       lock_time: PackedLockTime::ZERO,
+                       input: vec![TxIn { // Fee input
+                               previous_output: bitcoin::OutPoint { txid: coinbase_tx.txid(), vout: 0 },
+                               ..Default::default()
+                       }],
+                       output: vec![TxOut { // Fee input change
+                               value: coinbase_tx.output[0].value / 2 ,
+                               script_pubkey: Script::new_op_return(&[]),
+                       }],
+               };
+               let mut descriptors = Vec::with_capacity(4);
+               for event in events {
+                       if let Event::BumpTransaction(BumpTransactionEvent::HTLCResolution { mut htlc_descriptors, .. }) = event {
+                               assert_eq!(htlc_descriptors.len(), 2);
+                               for htlc_descriptor in &htlc_descriptors {
+                                       assert!(!htlc_descriptor.htlc.offered);
+                                       let signer = nodes[1].keys_manager.derive_channel_keys(
+                                               htlc_descriptor.channel_value_satoshis, &htlc_descriptor.channel_keys_id
+                                       );
+                                       let per_commitment_point = signer.get_per_commitment_point(htlc_descriptor.per_commitment_number, &secp);
+                                       htlc_tx.input.push(htlc_descriptor.unsigned_tx_input());
+                                       htlc_tx.output.push(htlc_descriptor.tx_output(&per_commitment_point, &secp));
+                               }
+                               descriptors.append(&mut htlc_descriptors);
+                       } else {
+                               panic!("Unexpected event");
+                       }
+               }
+               for (idx, htlc_descriptor) in descriptors.into_iter().enumerate() {
+                       let htlc_input_idx = idx + 1;
+                       let signer = nodes[1].keys_manager.derive_channel_keys(
+                               htlc_descriptor.channel_value_satoshis, &htlc_descriptor.channel_keys_id
+                       );
+                       let our_sig = signer.sign_holder_htlc_transaction(&htlc_tx, htlc_input_idx, &htlc_descriptor, &secp).unwrap();
+                       let per_commitment_point = signer.get_per_commitment_point(htlc_descriptor.per_commitment_number, &secp);
+                       let witness_script = htlc_descriptor.witness_script(&per_commitment_point, &secp);
+                       htlc_tx.input[htlc_input_idx].witness = htlc_descriptor.tx_input_witness(&our_sig, &witness_script);
+               }
+               let fee_utxo_sig = {
+                       let witness_script = Script::new_p2pkh(&public_key.pubkey_hash());
+                       let sighash = hash_to_message!(&SighashCache::new(&htlc_tx).segwit_signature_hash(
+                               0, &witness_script, coinbase_tx.output[0].value, EcdsaSighashType::All
+                       ).unwrap()[..]);
+                       let sig = sign(&secp, &sighash, &secret_key);
+                       let mut sig = sig.serialize_der().to_vec();
+                       sig.push(EcdsaSighashType::All as u8);
+                       sig
+               };
+               htlc_tx.input[0].witness = Witness::from_vec(vec![fee_utxo_sig, public_key.to_bytes()]);
+               check_spends!(htlc_tx, coinbase_tx, revoked_commitment_a, revoked_commitment_b);
+               htlc_tx
+       };
+
+       for node in &nodes {
+               mine_transaction(node, &htlc_tx);
+       }
+
+       // Alice should see that Bob is trying to claim to HTLCs, so she should now try to claim them at
+       // the second level instead.
+       let revoked_claims = {
+               let txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+               assert_eq!(txn.len(), 4);
+
+               let revoked_to_self_claim_a = txn.iter().find(|tx|
+                       tx.input.len() == 1 &&
+                       tx.output.len() == 1 &&
+                       tx.input[0].previous_output.txid == revoked_commitment_a.txid()
+               ).unwrap();
+               check_spends!(revoked_to_self_claim_a, revoked_commitment_a);
+
+               let revoked_to_self_claim_b = txn.iter().find(|tx|
+                       tx.input.len() == 1 &&
+                       tx.output.len() == 1 &&
+                       tx.input[0].previous_output.txid == revoked_commitment_b.txid()
+               ).unwrap();
+               check_spends!(revoked_to_self_claim_b, revoked_commitment_b);
+
+               let revoked_htlc_claims = txn.iter().filter(|tx|
+                       tx.input.len() == 2 &&
+                       tx.output.len() == 1 &&
+                       tx.input[0].previous_output.txid == htlc_tx.txid()
+               ).collect::<Vec<_>>();
+               assert_eq!(revoked_htlc_claims.len(), 2);
+               for revoked_htlc_claim in revoked_htlc_claims {
+                       check_spends!(revoked_htlc_claim, htlc_tx);
+               }
+
+               txn
+       };
+       for node in &nodes {
+               mine_transactions(node, &revoked_claims.iter().collect::<Vec<_>>());
+       }
+
+
+       // Connect one block to make sure the HTLC events are not yielded while ANTI_REORG_DELAY has not
+       // been reached.
+       connect_blocks(&nodes[0], 1);
+       connect_blocks(&nodes[1], 1);
+
+       assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+       assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+
+       // Connect the remaining blocks to reach ANTI_REORG_DELAY.
+       connect_blocks(&nodes[0], ANTI_REORG_DELAY - 2);
+       connect_blocks(&nodes[1], ANTI_REORG_DELAY - 2);
+
+       assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+       let spendable_output_events = nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events();
+       assert_eq!(spendable_output_events.len(), 4);
+       for (idx, event) in spendable_output_events.iter().enumerate() {
+               if let Event::SpendableOutputs { outputs } = event {
+                       assert_eq!(outputs.len(), 1);
+                       let spend_tx = nodes[0].keys_manager.backing.spend_spendable_outputs(
+                               &[&outputs[0]], Vec::new(), Script::new_op_return(&[]), 253, &Secp256k1::new(),
+                       ).unwrap();
+                       check_spends!(spend_tx, revoked_claims[idx]);
+               } else {
+                       panic!("unexpected event");
+               }
+       }
+
+       assert!(nodes[0].node.list_channels().is_empty());
+       assert!(nodes[1].node.list_channels().is_empty());
+       assert!(nodes[0].chain_monitor.chain_monitor.get_claimable_balances(&[]).is_empty());
+       // TODO: From Bob's PoV, he still thinks he can claim the outputs from his revoked commitment.
+       // This needs to be fixed before we enable pruning `ChannelMonitor`s once they don't have any
+       // balances to claim.
+       //
+       // The 6 claimable balances correspond to his `to_self` outputs and the 2 HTLC outputs in each
+       // revoked commitment which Bob has the preimage for.
+       assert_eq!(nodes[1].chain_monitor.chain_monitor.get_claimable_balances(&[]).len(), 6);
+}