Merge pull request #1324 from valentinewallace/2022-02-phantom-followup
[rust-lightning] / lightning / src / ln / onion_route_tests.rs
index 4feae104d759a11fb47ee0b21b1f8f4be20b2311..414c98d4e85da80ee3f0ada988d5835f36ea8e13 100644 (file)
 //! returned errors decode to the correct thing.
 
 use chain::channelmonitor::{CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS};
+use chain::keysinterface::{KeysInterface, Recipient};
 use ln::{PaymentHash, PaymentSecret};
-use ln::channelmanager::{HTLCForwardInfo, CLTV_FAR_FAR_AWAY};
+use ln::channelmanager::{HTLCForwardInfo, CLTV_FAR_FAR_AWAY, MIN_CLTV_EXPIRY_DELTA, PendingHTLCInfo, PendingHTLCRouting};
 use ln::onion_utils;
-use routing::network_graph::NetworkUpdate;
-use routing::router::Route;
-use ln::features::InitFeatures;
+use routing::network_graph::{NetworkUpdate, RoutingFees};
+use routing::router::{get_route, PaymentParameters, Route, RouteHint, RouteHintHop};
+use ln::features::{InitFeatures, InvoiceFeatures};
 use ln::msgs;
 use ln::msgs::{ChannelMessageHandler, ChannelUpdate, OptionalField};
 use util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
 use util::ser::{Writeable, Writer};
+use util::{byte_utils, test_utils};
 use util::config::UserConfig;
 
 use bitcoin::hash_types::BlockHash;
 
 use bitcoin::hashes::Hash;
+use bitcoin::hashes::sha256::Hash as Sha256;
 
 use bitcoin::secp256k1;
 use bitcoin::secp256k1::Secp256k1;
-use bitcoin::secp256k1::key::SecretKey;
+use bitcoin::secp256k1::key::{PublicKey, SecretKey};
 
 use io;
 use prelude::*;
@@ -573,3 +576,420 @@ fn test_onion_failure() {
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, true, Some(23), None, None);
 }
+
+macro_rules! get_phantom_route {
+       ($nodes: expr, $amt: expr, $channel: expr) => {{
+               let secp_ctx = Secp256k1::new();
+               let phantom_secret = $nodes[1].keys_manager.get_node_secret(Recipient::PhantomNode).unwrap();
+               let phantom_pubkey = PublicKey::from_secret_key(&secp_ctx, &phantom_secret);
+               let phantom_route_hint = $nodes[1].node.get_phantom_route_hints();
+               let payment_params = PaymentParameters::from_node_id(phantom_pubkey)
+                       .with_features(InvoiceFeatures::known())
+                       .with_route_hints(vec![RouteHint(vec![
+                                       RouteHintHop {
+                                               src_node_id: $nodes[0].node.get_our_node_id(),
+                                               short_channel_id: $channel.0.contents.short_channel_id,
+                                               fees: RoutingFees {
+                                                       base_msat: $channel.0.contents.fee_base_msat,
+                                                       proportional_millionths: $channel.0.contents.fee_proportional_millionths,
+                                               },
+                                               cltv_expiry_delta: $channel.0.contents.cltv_expiry_delta,
+                                               htlc_minimum_msat: None,
+                                               htlc_maximum_msat: None,
+                                       },
+                                       RouteHintHop {
+                                               src_node_id: phantom_route_hint.real_node_pubkey,
+                                               short_channel_id: phantom_route_hint.phantom_scid,
+                                               fees: RoutingFees {
+                                                       base_msat: 0,
+                                                       proportional_millionths: 0,
+                                               },
+                                               cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
+                                               htlc_minimum_msat: None,
+                                               htlc_maximum_msat: None,
+                                       }
+               ])]);
+               let scorer = test_utils::TestScorer::with_penalty(0);
+               (get_route(
+                       &$nodes[0].node.get_our_node_id(), &payment_params, $nodes[0].network_graph,
+                       Some(&$nodes[0].node.list_usable_channels().iter().collect::<Vec<_>>()),
+                       $amt, TEST_FINAL_CLTV, $nodes[0].logger, &scorer
+               ).unwrap(), phantom_route_hint.phantom_scid)
+       }
+}}
+
+#[test]
+fn test_phantom_onion_hmac_failure() {
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route.
+       let recv_value_msat = 10_000;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
+       let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       // Modify the payload so the phantom hop's HMAC is bogus.
+       let sha256_of_onion = {
+               let mut channel_state = nodes[1].node.channel_state.lock().unwrap();
+               let mut pending_forward = channel_state.forward_htlcs.get_mut(&phantom_scid).unwrap();
+               match pending_forward[0] {
+                       HTLCForwardInfo::AddHTLC {
+                               forward_info: PendingHTLCInfo {
+                                       routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
+                                       ..
+                               }, ..
+                       } => {
+                               onion_packet.hmac[onion_packet.hmac.len() - 1] ^= 1;
+                               Sha256::hash(&onion_packet.hop_data).into_inner().to_vec()
+                       },
+                       _ => panic!("Unexpected forward"),
+               }
+       };
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .blamed_chan_closed(true)
+               .expected_htlc_error_data(0x8000 | 0x4000 | 5, &sha256_of_onion);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
+}
+
+#[test]
+fn test_phantom_invalid_onion_payload() {
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route.
+       let recv_value_msat = 10_000;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
+       let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);
+
+       // We'll use the session priv later when constructing an invalid onion packet.
+       let session_priv = [3; 32];
+       *nodes[0].keys_manager.override_session_priv.lock().unwrap() = Some(session_priv);
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       // Modify the onion packet to have an invalid payment amount.
+       for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
+               for f in pending_forwards.iter_mut() {
+                       match f {
+                               &mut HTLCForwardInfo::AddHTLC {
+                                       forward_info: PendingHTLCInfo {
+                                               routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
+                                               ..
+                                       }, ..
+                               } => {
+                                       // Construct the onion payloads for the entire route and an invalid amount.
+                                       let height = nodes[0].best_block_info().1;
+                                       let session_priv = SecretKey::from_slice(&session_priv).unwrap();
+                                       let mut onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
+                                       let (mut onion_payloads, _, _) = onion_utils::build_onion_payloads(&route.paths[0], msgs::MAX_VALUE_MSAT + 1, &Some(payment_secret), height + 1, &None).unwrap();
+                                       // We only want to construct the onion packet for the last hop, not the entire route, so
+                                       // remove the first hop's payload and its keys.
+                                       onion_keys.remove(0);
+                                       onion_payloads.remove(0);
+
+                                       let new_onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &payment_hash);
+                                       onion_packet.hop_data = new_onion_packet.hop_data;
+                                       onion_packet.hmac = new_onion_packet.hmac;
+                               },
+                               _ => panic!("Unexpected forward"),
+                       }
+               }
+       }
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let error_data = Vec::new();
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .blamed_chan_closed(true)
+               .expected_htlc_error_data(0x4000 | 22, &error_data);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
+}
+
+#[test]
+fn test_phantom_final_incorrect_cltv_expiry() {
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route.
+       let recv_value_msat = 10_000;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
+       let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       // Modify the payload so the phantom hop's HMAC is bogus.
+       for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
+               for f in pending_forwards.iter_mut() {
+                       match f {
+                               &mut HTLCForwardInfo::AddHTLC {
+                                       forward_info: PendingHTLCInfo { ref mut outgoing_cltv_value, .. }, ..
+                               } => {
+                                       *outgoing_cltv_value += 1;
+                               },
+                               _ => panic!("Unexpected forward"),
+                       }
+               }
+       }
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let expected_cltv = 82;
+       let error_data = byte_utils::be32_to_array(expected_cltv).to_vec();
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .expected_htlc_error_data(18, &error_data);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
+}
+
+#[test]
+fn test_phantom_failure_too_low_cltv() {
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route.
+       let recv_value_msat = 10_000;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
+       let (mut route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);
+
+       // Modify the route to have a too-low cltv.
+       route.paths[0][1].cltv_expiry_delta = 5;
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let error_data = Vec::new();
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .expected_htlc_error_data(17, &error_data);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
+}
+
+#[test]
+fn test_phantom_failure_too_low_recv_amt() {
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route with a too-low amount.
+       let recv_amt_msat = 10_000;
+       let bad_recv_amt_msat = recv_amt_msat - 10;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_amt_msat));
+       let (mut route, phantom_scid) = get_phantom_route!(nodes, bad_recv_amt_msat, channel);
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let mut error_data = byte_utils::be64_to_array(bad_recv_amt_msat).to_vec();
+       error_data.extend_from_slice(
+               &byte_utils::be32_to_array(nodes[1].node.best_block.read().unwrap().height()),
+       );
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .expected_htlc_error_data(0x4000 | 15, &error_data);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
+}
+
+#[test]
+fn test_phantom_dust_exposure_failure() {
+       // Set the max dust exposure to the dust limit.
+       let max_dust_exposure = 546;
+       let mut receiver_config = UserConfig::default();
+       receiver_config.channel_options.max_dust_htlc_exposure_msat = max_dust_exposure;
+       receiver_config.channel_options.announced_channel = true;
+
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, Some(receiver_config)]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route with an amount exceeding the dust exposure threshold of nodes[1].
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(max_dust_exposure + 1));
+       let (mut route, _) = get_phantom_route!(nodes, max_dust_exposure + 1, channel);
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let mut error_data = channel.1.encode_with_len();
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(channel.0.contents.short_channel_id)
+               .blamed_chan_closed(false)
+               .expected_htlc_error_data(0x1000 | 7, &error_data);
+               expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
+}
+
+#[test]
+fn test_phantom_failure_reject_payment() {
+       // Test that the user can successfully fail back a phantom node payment.
+       let chanmon_cfgs = create_chanmon_cfgs(2);
+       let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+       let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Get the route with a too-low amount.
+       let recv_amt_msat = 10_000;
+       let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_amt_msat));
+       let (mut route, phantom_scid) = get_phantom_route!(nodes, recv_amt_msat, channel);
+
+       // Route the HTLC through to the destination.
+       nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+       let mut update_add = update_0.update_add_htlcs[0].clone();
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
+       commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);
+
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+       expect_payment_received!(nodes[1], payment_hash, payment_secret, recv_amt_msat);
+       assert!(nodes[1].node.fail_htlc_backwards(&payment_hash));
+       expect_pending_htlcs_forwardable_ignore!(nodes[1]);
+       nodes[1].node.process_pending_htlc_forwards();
+
+       let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+       check_added_monitors!(&nodes[1], 1);
+       assert!(update_1.update_fail_htlcs.len() == 1);
+       let fail_msg = update_1.update_fail_htlcs[0].clone();
+       nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+       commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);
+
+       // Ensure the payment fails with the expected error.
+       let mut error_data = byte_utils::be64_to_array(recv_amt_msat).to_vec();
+       error_data.extend_from_slice(
+               &byte_utils::be32_to_array(nodes[1].node.best_block.read().unwrap().height()),
+       );
+       let mut fail_conditions = PaymentFailedConditions::new()
+               .blamed_scid(phantom_scid)
+               .expected_htlc_error_data(0x4000 | 15, &error_data);
+       expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
+}
+