Isolated channelmonitor weight unit tests and added anchor loops
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index dd33e7d0d02ea4d6f1e33d99ea0ddac75bfcf3c6..d749c0a4b976efecaad5773cdef6f215327e5d68 100644 (file)
@@ -115,14 +115,6 @@ impl Readable for ChannelMonitorUpdate {
        }
 }
 
-/// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
-/// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
-/// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
-/// corrupted.
-/// Contains a developer-readable error message.
-#[derive(Clone, Debug)]
-pub struct MonitorUpdateError(pub &'static str);
-
 /// An event to be processed by the ChannelManager.
 #[derive(Clone, PartialEq)]
 pub enum MonitorEvent {
@@ -695,6 +687,11 @@ pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        // remote monitor out-of-order with regards to the block view.
        holder_tx_signed: bool,
 
+       // If a spend of the funding output is seen, we set this to true and reject any further
+       // updates. This prevents any further changes in the offchain state no matter the order
+       // of block connection between ChannelMonitors and the ChannelManager.
+       funding_spend_seen: bool,
+
        funding_spend_confirmed: Option<Txid>,
        /// The set of HTLCs which have been either claimed or failed on chain and have reached
        /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
@@ -760,6 +757,7 @@ impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
                        self.outputs_to_watch != other.outputs_to_watch ||
                        self.lockdown_from_offchain != other.lockdown_from_offchain ||
                        self.holder_tx_signed != other.holder_tx_signed ||
+                       self.funding_spend_seen != other.funding_spend_seen ||
                        self.funding_spend_confirmed != other.funding_spend_confirmed ||
                        self.htlcs_resolved_on_chain != other.htlcs_resolved_on_chain
                {
@@ -935,6 +933,7 @@ impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
                        (1, self.funding_spend_confirmed, option),
                        (3, self.htlcs_resolved_on_chain, vec_type),
                        (5, self.pending_monitor_events, vec_type),
+                       (7, self.funding_spend_seen, required),
                });
 
                Ok(())
@@ -1033,6 +1032,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 
                                lockdown_from_offchain: false,
                                holder_tx_signed: false,
+                               funding_spend_seen: false,
                                funding_spend_confirmed: None,
                                htlcs_resolved_on_chain: Vec::new(),
 
@@ -1044,7 +1044,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
        }
 
        #[cfg(test)]
-       fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
+       fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
                self.inner.lock().unwrap().provide_secret(idx, secret)
        }
 
@@ -1066,12 +1066,10 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 
        #[cfg(test)]
        fn provide_latest_holder_commitment_tx(
-               &self,
-               holder_commitment_tx: HolderCommitmentTransaction,
+               &self, holder_commitment_tx: HolderCommitmentTransaction,
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
-       ) -> Result<(), MonitorUpdateError> {
-               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
-                       holder_commitment_tx, htlc_outputs)
+       ) -> Result<(), ()> {
+               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs).map_err(|_| ())
        }
 
        #[cfg(test)]
@@ -1112,7 +1110,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                broadcaster: &B,
                fee_estimator: &F,
                logger: &L,
-       ) -> Result<(), MonitorUpdateError>
+       ) -> Result<(), ()>
        where
                B::Target: BroadcasterInterface,
                F::Target: FeeEstimator,
@@ -1687,9 +1685,9 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
        /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
        /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
-       fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
+       fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
                if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
-                       return Err(MonitorUpdateError("Previous secret did not match new one"));
+                       return Err("Previous secret did not match new one");
                }
 
                // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
@@ -1781,7 +1779,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        /// is important that any clones of this channel monitor (including remote clones) by kept
        /// up-to-date as our holder commitment transaction is updated.
        /// Panics if set_on_holder_tx_csv has never been called.
-       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
+       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), &'static str> {
                // block for Rust 1.34 compat
                let mut new_holder_commitment_tx = {
                        let trusted_tx = holder_commitment_tx.trust();
@@ -1804,7 +1802,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
                self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
                if self.holder_tx_signed {
-                       return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
+                       return Err("Latest holder commitment signed has already been signed, update is rejected");
                }
                Ok(())
        }
@@ -1868,7 +1866,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
        }
 
-       pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
+       pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), ()>
        where B::Target: BroadcasterInterface,
                    F::Target: FeeEstimator,
                    L::Target: Logger,
@@ -1894,8 +1892,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        if self.lockdown_from_offchain { panic!(); }
                                        if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone()) {
                                                log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
-                                               log_error!(logger, "    {}", e.0);
-                                               ret = Err(e);
+                                               log_error!(logger, "    {}", e);
+                                               ret = Err(());
                                        }
                                }
                                ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
@@ -1910,8 +1908,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        log_trace!(logger, "Updating ChannelMonitor with commitment secret");
                                        if let Err(e) = self.provide_secret(*idx, *secret) {
                                                log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
-                                               log_error!(logger, "    {}", e.0);
-                                               ret = Err(e);
+                                               log_error!(logger, "    {}", e);
+                                               ret = Err(());
                                        }
                                },
                                ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
@@ -1937,7 +1935,11 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        }
                }
                self.latest_update_id = updates.update_id;
-               ret
+
+               if ret.is_ok() && self.funding_spend_seen {
+                       log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
+                       Err(())
+               } else { ret }
        }
 
        pub fn get_latest_update_id(&self) -> u64 {
@@ -2366,6 +2368,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        let mut balance_spendable_csv = None;
                                        log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
                                                log_bytes!(self.funding_info.0.to_channel_id()), tx.txid());
+                                       self.funding_spend_seen = true;
                                        if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
                                                let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
                                                if !new_outputs.1.is_empty() {
@@ -3215,10 +3218,12 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
 
                let mut funding_spend_confirmed = None;
                let mut htlcs_resolved_on_chain = Some(Vec::new());
+               let mut funding_spend_seen = Some(false);
                read_tlv_fields!(reader, {
                        (1, funding_spend_confirmed, option),
                        (3, htlcs_resolved_on_chain, vec_type),
                        (5, pending_monitor_events, vec_type),
+                       (7, funding_spend_seen, option),
                });
 
                let mut secp_ctx = Secp256k1::new();
@@ -3268,6 +3273,7 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
 
                                lockdown_from_offchain,
                                holder_tx_signed,
+                               funding_spend_seen: funding_spend_seen.unwrap(),
                                funding_spend_confirmed,
                                htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
 
@@ -3281,6 +3287,7 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
 
 #[cfg(test)]
 mod tests {
+       use bitcoin::blockdata::block::BlockHeader;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::opcodes;
        use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
@@ -3289,24 +3296,128 @@ mod tests {
        use bitcoin::hashes::Hash;
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::hex::FromHex;
-       use bitcoin::hash_types::Txid;
+       use bitcoin::hash_types::{BlockHash, Txid};
        use bitcoin::network::constants::Network;
+       use bitcoin::secp256k1::key::{SecretKey,PublicKey};
+       use bitcoin::secp256k1::Secp256k1;
+
        use hex;
-       use chain::BestBlock;
+
+       use super::ChannelMonitorUpdateStep;
+       use ::{check_added_monitors, check_closed_broadcast, check_closed_event, check_spends, get_local_commitment_txn, get_monitor, get_route_and_payment_hash, unwrap_send_err};
+       use chain::{BestBlock, Confirm};
        use chain::channelmonitor::ChannelMonitor;
        use chain::package::{WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC, WEIGHT_REVOKED_OUTPUT};
        use chain::transaction::OutPoint;
+       use chain::keysinterface::InMemorySigner;
        use ln::{PaymentPreimage, PaymentHash};
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
+       use ln::channelmanager::PaymentSendFailure;
+       use ln::features::InitFeatures;
+       use ln::functional_test_utils::*;
        use ln::script::ShutdownScript;
+       use util::errors::APIError;
+       use util::events::{ClosureReason, MessageSendEventsProvider};
        use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
-       use bitcoin::secp256k1::key::{SecretKey,PublicKey};
-       use bitcoin::secp256k1::Secp256k1;
+       use util::ser::{ReadableArgs, Writeable};
        use sync::{Arc, Mutex};
-       use chain::keysinterface::InMemorySigner;
+       use io;
        use prelude::*;
 
+       fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
+               // Previously, monitor updates were allowed freely even after a funding-spend transaction
+               // confirmed. This would allow a race condition where we could receive a payment (including
+               // the counterparty revoking their broadcasted state!) and accept it without recourse as
+               // long as the ChannelMonitor receives the block first, the full commitment update dance
+               // occurs after the block is connected, and before the ChannelManager receives the block.
+               // Obviously this is an incredibly contrived race given the counterparty would be risking
+               // their full channel balance for it, but its worth fixing nonetheless as it makes the
+               // potential ChannelMonitor states simpler to reason about.
+               //
+               // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
+               // updates is handled correctly in such conditions.
+               let chanmon_cfgs = create_chanmon_cfgs(3);
+               let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+               let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+               let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+               let channel = create_announced_chan_between_nodes(
+                       &nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+               create_announced_chan_between_nodes(
+                       &nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
+
+               // Rebalance somewhat
+               send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
+
+               // First route two payments for testing at the end
+               let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
+               let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
+
+               let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
+               assert_eq!(local_txn.len(), 1);
+               let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
+               assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
+               check_spends!(remote_txn[1], remote_txn[0]);
+               check_spends!(remote_txn[2], remote_txn[0]);
+               let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
+
+               // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
+               // channel is now closed, but the ChannelManager doesn't know that yet.
+               let new_header = BlockHeader {
+                       version: 2, time: 0, bits: 0, nonce: 0,
+                       prev_blockhash: nodes[0].best_block_info().0,
+                       merkle_root: Default::default() };
+               let conf_height = nodes[0].best_block_info().1 + 1;
+               nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
+                       &[(0, broadcast_tx)], conf_height);
+
+               let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
+                                               &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
+                                               &nodes[1].keys_manager.backing).unwrap();
+
+               // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
+               // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
+               let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
+               unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret)),
+                       true, APIError::ChannelUnavailable { ref err },
+                       assert!(err.contains("ChannelMonitor storage failure")));
+               check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
+               check_closed_broadcast!(nodes[1], true);
+               check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
+
+               // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
+               // and provides the claim preimages for the two pending HTLCs. The first update generates
+               // an error, but the point of this test is to ensure the later updates are still applied.
+               let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
+               let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
+               assert_eq!(replay_update.updates.len(), 1);
+               if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
+               } else { panic!(); }
+               replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
+               replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
+
+               let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
+               assert!(
+                       pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &&chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
+                       .is_err());
+               // Even though we error'd on the first update, we should still have generated an HTLC claim
+               // transaction
+               let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+               assert!(txn_broadcasted.len() >= 2);
+               let htlc_txn = txn_broadcasted.iter().filter(|tx| {
+                       assert_eq!(tx.input.len(), 1);
+                       tx.input[0].previous_output.txid == broadcast_tx.txid()
+               }).collect::<Vec<_>>();
+               assert_eq!(htlc_txn.len(), 2);
+               check_spends!(htlc_txn[0], broadcast_tx);
+               check_spends!(htlc_txn[1], broadcast_tx);
+       }
+       #[test]
+       fn test_funding_spend_refuses_updates() {
+               do_test_funding_spend_refuses_updates(true);
+               do_test_funding_spend_refuses_updates(false);
+       }
+
        #[test]
        fn test_prune_preimages() {
                let secp_ctx = Secp256k1::new();
@@ -3453,7 +3564,6 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
                let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
-               let mut sum_actual_sigs = 0;
 
                macro_rules! sign_input {
                        ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
@@ -3469,7 +3579,7 @@ mod tests {
                                let sig = secp_ctx.sign(&sighash, &privkey);
                                $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
                                $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
-                               sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
+                               $sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
                                if *$weight == WEIGHT_REVOKED_OUTPUT {
                                        $sighash_parts.access_witness($idx).push(vec!(1));
                                } else if *$weight == WEIGHT_REVOKED_OFFERED_HTLC || *$weight == WEIGHT_REVOKED_RECEIVED_HTLC {
@@ -3490,83 +3600,98 @@ mod tests {
                let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
 
                // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
-               let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
-               for i in 0..4 {
-                       claim_tx.input.push(TxIn {
-                               previous_output: BitcoinOutPoint {
-                                       txid,
-                                       vout: i,
-                               },
-                               script_sig: Script::new(),
-                               sequence: 0xfffffffd,
-                               witness: Vec::new(),
+               for &opt_anchors in [false, true].iter() {
+                       let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
+                       let mut sum_actual_sigs = 0;
+                       for i in 0..4 {
+                               claim_tx.input.push(TxIn {
+                                       previous_output: BitcoinOutPoint {
+                                               txid,
+                                               vout: i,
+                                       },
+                                       script_sig: Script::new(),
+                                       sequence: 0xfffffffd,
+                                       witness: Vec::new(),
+                               });
+                       }
+                       claim_tx.output.push(TxOut {
+                               script_pubkey: script_pubkey.clone(),
+                               value: 0,
                        });
-               }
-               claim_tx.output.push(TxOut {
-                       script_pubkey: script_pubkey.clone(),
-                       value: 0,
-               });
-               let base_weight = claim_tx.get_weight();
-               let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC];
-               let mut inputs_total_weight = 2; // count segwit flags
-               {
-                       let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
-                       for (idx, inp) in inputs_weight.iter().enumerate() {
-                               sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, false);
-                               inputs_total_weight += inp;
+                       let base_weight = claim_tx.get_weight();
+                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC];
+                       let mut inputs_total_weight = 2; // count segwit flags
+                       {
+                               let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
+                               for (idx, inp) in inputs_weight.iter().enumerate() {
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       inputs_total_weight += inp;
+                               }
                        }
+                       assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
                }
-               assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
 
                // Claim tx with 1 offered HTLCs, 3 received HTLCs
-               claim_tx.input.clear();
-               sum_actual_sigs = 0;
-               for i in 0..4 {
+               for &opt_anchors in [false, true].iter() {
+                       let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
+                       let mut sum_actual_sigs = 0;
+                       for i in 0..4 {
+                               claim_tx.input.push(TxIn {
+                                       previous_output: BitcoinOutPoint {
+                                               txid,
+                                               vout: i,
+                                       },
+                                       script_sig: Script::new(),
+                                       sequence: 0xfffffffd,
+                                       witness: Vec::new(),
+                               });
+                       }
+                       claim_tx.output.push(TxOut {
+                               script_pubkey: script_pubkey.clone(),
+                               value: 0,
+                       });
+                       let base_weight = claim_tx.get_weight();
+                       let inputs_weight = vec![WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC];
+                       let mut inputs_total_weight = 2; // count segwit flags
+                       {
+                               let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
+                               for (idx, inp) in inputs_weight.iter().enumerate() {
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       inputs_total_weight += inp;
+                               }
+                       }
+                       assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
+               }
+
+               // Justice tx with 1 revoked HTLC-Success tx output
+               for &opt_anchors in [false, true].iter() {
+                       let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
+                       let mut sum_actual_sigs = 0;
                        claim_tx.input.push(TxIn {
                                previous_output: BitcoinOutPoint {
                                        txid,
-                                       vout: i,
+                                       vout: 0,
                                },
                                script_sig: Script::new(),
                                sequence: 0xfffffffd,
                                witness: Vec::new(),
                        });
-               }
-               let base_weight = claim_tx.get_weight();
-               let inputs_weight = vec![WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC];
-               let mut inputs_total_weight = 2; // count segwit flags
-               {
-                       let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
-                       for (idx, inp) in inputs_weight.iter().enumerate() {
-                               sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, false);
-                               inputs_total_weight += inp;
-                       }
-               }
-               assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
-
-               // Justice tx with 1 revoked HTLC-Success tx output
-               claim_tx.input.clear();
-               sum_actual_sigs = 0;
-               claim_tx.input.push(TxIn {
-                       previous_output: BitcoinOutPoint {
-                               txid,
-                               vout: 0,
-                       },
-                       script_sig: Script::new(),
-                       sequence: 0xfffffffd,
-                       witness: Vec::new(),
-               });
-               let base_weight = claim_tx.get_weight();
-               let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
-               let mut inputs_total_weight = 2; // count segwit flags
-               {
-                       let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
-                       for (idx, inp) in inputs_weight.iter().enumerate() {
-                               sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, false);
-                               inputs_total_weight += inp;
+                       claim_tx.output.push(TxOut {
+                               script_pubkey: script_pubkey.clone(),
+                               value: 0,
+                       });
+                       let base_weight = claim_tx.get_weight();
+                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
+                       let mut inputs_total_weight = 2; // count segwit flags
+                       {
+                               let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
+                               for (idx, inp) in inputs_weight.iter().enumerate() {
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       inputs_total_weight += inp;
+                               }
                        }
+                       assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
                }
-               assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
        }
 
        // Further testing is done in the ChannelManager integration tests.