_ Git - rust-lightning/blob - lightning/src/ln/blinded_payment_tests.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
  11 use crate::blinded_path::BlindedPath;
  12 use crate::blinded_path::payment::{ForwardNode, ForwardTlvs, PaymentConstraints, PaymentRelay, ReceiveTlvs};
  13 use crate::events::{Event, HTLCDestination, MessageSendEvent, MessageSendEventsProvider, PaymentFailureReason};
  14 use crate::ln::PaymentSecret;
  15 use crate::ln::channelmanager;
  16 use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
  17 use crate::ln::features::BlindedHopFeatures;
  18 use crate::ln::functional_test_utils::*;
  19 use crate::ln::msgs;
  20 use crate::ln::msgs::ChannelMessageHandler;
  21 use crate::ln::onion_utils;
  22 use crate::ln::onion_utils::INVALID_ONION_BLINDING;
  23 use crate::ln::outbound_payment::Retry;
  24 use crate::offers::invoice::BlindedPayInfo;
  25 use crate::prelude::*;
  26 use crate::routing::router::{Payee, PaymentParameters, RouteParameters};
  27 use crate::util::config::UserConfig;
  28 use crate::util::test_utils;
  29
  30 fn blinded_payment_path(
  31         payment_secret: PaymentSecret, node_ids: Vec<PublicKey>,
  32         channel_upds: &[&msgs::UnsignedChannelUpdate], keys_manager: &test_utils::TestKeysInterface
  33 ) -> (BlindedPayInfo, BlindedPath) {
  34         let mut intermediate_nodes = Vec::new();
  35         for (node_id, chan_upd) in node_ids.iter().zip(channel_upds) {
  36                 intermediate_nodes.push(ForwardNode {
  37                         node_id: *node_id,
  38                         tlvs: ForwardTlvs {
  39                                 short_channel_id: chan_upd.short_channel_id,
  40                                 payment_relay: PaymentRelay {
  41                                         cltv_expiry_delta: chan_upd.cltv_expiry_delta,
  42                                         fee_proportional_millionths: chan_upd.fee_proportional_millionths,
  43                                         fee_base_msat: chan_upd.fee_base_msat,
  44                                 },
  45                                 payment_constraints: PaymentConstraints {
  46                                         max_cltv_expiry: u32::max_value(),
  47                                         htlc_minimum_msat: chan_upd.htlc_minimum_msat,
  48                                 },
  49                                 features: BlindedHopFeatures::empty(),
  50                         },
  51                         htlc_maximum_msat: chan_upd.htlc_maximum_msat,
  52                 });
  53         }
  54         let payee_tlvs = ReceiveTlvs {
  55                 payment_secret,
  56                 payment_constraints: PaymentConstraints {
  57                         max_cltv_expiry: u32::max_value(),
  58                         htlc_minimum_msat: channel_upds.last().unwrap().htlc_minimum_msat,
  59                 },
  60         };
  61         let mut secp_ctx = Secp256k1::new();
  62         BlindedPath::new_for_payment(
  63                 &intermediate_nodes[..], *node_ids.last().unwrap(), payee_tlvs,
  64                 channel_upds.last().unwrap().htlc_maximum_msat, TEST_FINAL_CLTV as u16, keys_manager, &secp_ctx
  65         ).unwrap()
  66 }
  67
  68 pub fn get_blinded_route_parameters(
  69         amt_msat: u64, payment_secret: PaymentSecret, node_ids: Vec<PublicKey>,
  70         channel_upds: &[&msgs::UnsignedChannelUpdate], keys_manager: &test_utils::TestKeysInterface
  71 ) -> RouteParameters {
  72         RouteParameters::from_payment_params_and_value(
  73                 PaymentParameters::blinded(vec![
  74                         blinded_payment_path(payment_secret, node_ids, channel_upds, keys_manager)
  75                 ]), amt_msat
  76         )
  77 }
  78
  79 #[test]
  80 fn one_hop_blinded_path() {
  81         do_one_hop_blinded_path(true);
  82         do_one_hop_blinded_path(false);
  83 }
  84
  85 fn do_one_hop_blinded_path(success: bool) {
  86         let chanmon_cfgs = create_chanmon_cfgs(2);
  87         let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
  88         let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
  89         let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
  90         let chan_upd = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0).0.contents;
  91
  92         let amt_msat = 5000;
  93         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[1], Some(amt_msat), None);
  94         let payee_tlvs = ReceiveTlvs {
  95                 payment_secret,
  96                 payment_constraints: PaymentConstraints {
  97                         max_cltv_expiry: u32::max_value(),
  98                         htlc_minimum_msat: chan_upd.htlc_minimum_msat,
  99                 },
 100         };
 101         let mut secp_ctx = Secp256k1::new();
 102         let blinded_path = BlindedPath::one_hop_for_payment(
 103                 nodes[1].node.get_our_node_id(), payee_tlvs, TEST_FINAL_CLTV as u16,
 104                 &chanmon_cfgs[1].keys_manager, &secp_ctx
 105         ).unwrap();
 106
 107         let route_params = RouteParameters::from_payment_params_and_value(
 108                 PaymentParameters::blinded(vec![blinded_path]),
 109                 amt_msat,
 110         );
 111         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
 112         PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 113         check_added_monitors(&nodes[0], 1);
 114         pass_along_route(&nodes[0], &[&[&nodes[1]]], amt_msat, payment_hash, payment_secret);
 115         if success {
 116                 claim_payment(&nodes[0], &[&nodes[1]], payment_preimage);
 117         } else {
 118                 fail_payment(&nodes[0], &[&nodes[1]], payment_hash);
 119         }
 120 }
 121
 122 #[test]
 123 fn mpp_to_one_hop_blinded_path() {
 124         let chanmon_cfgs = create_chanmon_cfgs(4);
 125         let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
 126         let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
 127         let nodes = create_network(4, &node_cfgs, &node_chanmgrs);
 128         let mut secp_ctx = Secp256k1::new();
 129
 130         create_announced_chan_between_nodes(&nodes, 0, 1);
 131         create_announced_chan_between_nodes(&nodes, 0, 2);
 132         let chan_upd_1_3 = create_announced_chan_between_nodes(&nodes, 1, 3).0.contents;
 133         create_announced_chan_between_nodes(&nodes, 2, 3).0.contents;
 134
 135         let amt_msat = 15_000_000;
 136         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[3], Some(amt_msat), None);
 137         let payee_tlvs = ReceiveTlvs {
 138                 payment_secret,
 139                 payment_constraints: PaymentConstraints {
 140                         max_cltv_expiry: u32::max_value(),
 141                         htlc_minimum_msat: chan_upd_1_3.htlc_minimum_msat,
 142                 },
 143         };
 144         let blinded_path = BlindedPath::one_hop_for_payment(
 145                 nodes[3].node.get_our_node_id(), payee_tlvs, TEST_FINAL_CLTV as u16,
 146                 &chanmon_cfgs[3].keys_manager, &secp_ctx
 147         ).unwrap();
 148
 149         let bolt12_features =
 150                 channelmanager::provided_bolt12_invoice_features(&UserConfig::default());
 151         let route_params = RouteParameters::from_payment_params_and_value(
 152                 PaymentParameters::blinded(vec![blinded_path]).with_bolt12_features(bolt12_features).unwrap(),
 153                 amt_msat,
 154         );
 155         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 156         check_added_monitors(&nodes[0], 2);
 157
 158         let expected_route: &[&[&Node]] = &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]];
 159         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 160         assert_eq!(events.len(), 2);
 161
 162         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
 163         pass_along_path(&nodes[0], expected_route[0], amt_msat, payment_hash.clone(),
 164                 Some(payment_secret), ev.clone(), false, None);
 165
 166         let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
 167         pass_along_path(&nodes[0], expected_route[1], amt_msat, payment_hash.clone(),
 168                 Some(payment_secret), ev.clone(), true, None);
 169         claim_payment_along_route(&nodes[0], expected_route, false, payment_preimage);
 170 }
 171
 172 enum ForwardCheckFail {
 173         // Fail a check on the inbound onion payload. In this case, we underflow when calculating the
 174         // outgoing cltv_expiry.
 175         InboundOnionCheck,
 176         // The forwarding node's payload is encoded as a receive, i.e. the next hop HMAC is [0; 32].
 177         ForwardPayloadEncodedAsReceive,
 178         // Fail a check on the outbound channel. In this case, our next-hop peer is offline.
 179         OutboundChannelCheck,
 180 }
 181
 182 #[test]
 183 fn forward_checks_failure() {
 184         do_forward_checks_failure(ForwardCheckFail::InboundOnionCheck);
 185         do_forward_checks_failure(ForwardCheckFail::ForwardPayloadEncodedAsReceive);
 186         do_forward_checks_failure(ForwardCheckFail::OutboundChannelCheck);
 187 }
 188
 189 fn do_forward_checks_failure(check: ForwardCheckFail) {
 190         // Ensure we'll fail backwards properly if a forwarding check fails on initial update_add
 191         // receipt.
 192         let chanmon_cfgs = create_chanmon_cfgs(3);
 193         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 194         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 195         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 196         // We need the session priv to construct a bogus onion packet later.
 197         *nodes[0].keys_manager.override_random_bytes.lock().unwrap() = Some([3; 32]);
 198         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 199         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
 200
 201         let amt_msat = 5000;
 202         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
 203         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 204                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
 205                 &chanmon_cfgs[2].keys_manager);
 206
 207         let route = get_route(&nodes[0], &route_params).unwrap();
 208         node_cfgs[0].router.expect_find_route(route_params.clone(), Ok(route.clone()));
 209         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 210         check_added_monitors(&nodes[0], 1);
 211
 212         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 213         assert_eq!(events.len(), 1);
 214         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
 215         let mut payment_event = SendEvent::from_event(ev);
 216
 217         let mut update_add = &mut payment_event.msgs[0];
 218         match check {
 219                 ForwardCheckFail::InboundOnionCheck => {
 220                         update_add.cltv_expiry = 10; // causes outbound CLTV expiry to underflow
 221                 },
 222                 ForwardCheckFail::ForwardPayloadEncodedAsReceive => {
 223                         let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
 224                         let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
 225                         let cur_height = nodes[0].best_block_info().1;
 226                         let (mut onion_payloads, ..) = onion_utils::build_onion_payloads(
 227                                 &route.paths[0], amt_msat, RecipientOnionFields::spontaneous_empty(), cur_height, &None).unwrap();
 228                         // Remove the receive payload so the blinded forward payload is encoded as a final payload
 229                         // (i.e. next_hop_hmac == [0; 32])
 230                         onion_payloads.pop();
 231                         update_add.onion_routing_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &payment_hash).unwrap();
 232                 },
 233                 ForwardCheckFail::OutboundChannelCheck => {
 234                         // The intro node will see that the next-hop peer is disconnected and fail the HTLC backwards.
 235                         nodes[1].node.peer_disconnected(&nodes[2].node.get_our_node_id());
 236                 },
 237         }
 238         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 239         check_added_monitors!(nodes[1], 0);
 240         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, true, true);
 241
 242         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 243         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
 244         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
 245         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
 246                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
 247 }
 248
 249 #[test]
 250 fn failed_backwards_to_intro_node() {
 251         // Ensure the intro node will error backwards properly even if the downstream node did not blind
 252         // their error.
 253         let chanmon_cfgs = create_chanmon_cfgs(3);
 254         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 255         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 256         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 257         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 258         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
 259
 260         let amt_msat = 5000;
 261         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
 262         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 263                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
 264                 &chanmon_cfgs[2].keys_manager);
 265
 266         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 267         check_added_monitors(&nodes[0], 1);
 268
 269         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 270         assert_eq!(events.len(), 1);
 271         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
 272         let mut payment_event = SendEvent::from_event(ev);
 273
 274         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 275         check_added_monitors!(nodes[1], 0);
 276         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, false, false);
 277         expect_pending_htlcs_forwardable!(nodes[1]);
 278         check_added_monitors!(&nodes[1], 1);
 279
 280         let mut events = nodes[1].node.get_and_clear_pending_msg_events();
 281         assert_eq!(events.len(), 1);
 282         let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
 283         let mut payment_event = SendEvent::from_event(ev);
 284
 285         // Ensure the final node fails to handle the HTLC.
 286         payment_event.msgs[0].onion_routing_packet.hop_data[0] ^= 1;
 287         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
 288         check_added_monitors!(nodes[2], 0);
 289         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event.commitment_msg, true, true);
 290         nodes[2].node.process_pending_htlc_forwards();
 291
 292         let mut updates = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
 293         let mut update_malformed = &mut updates.update_fail_malformed_htlcs[0];
 294         // Check that the final node encodes its failure correctly.
 295         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
 296         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
 297
 298         // Modify such the final hop does not correctly blind their error so we can ensure the intro node
 299         // converts it to the correct error.
 300         update_malformed.sha256_of_onion = [1; 32];
 301         nodes[1].node.handle_update_fail_malformed_htlc(&nodes[2].node.get_our_node_id(), update_malformed);
 302         do_commitment_signed_dance(&nodes[1], &nodes[2], &updates.commitment_signed, true, false);
 303
 304         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 305         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
 306         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
 307         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
 308                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
 309 }
 310
 311 enum ProcessPendingHTLCsCheck {
 312         FwdPeerDisconnected,
 313         FwdChannelClosed,
 314 }
 315
 316 #[test]
 317 fn forward_fail_in_process_pending_htlc_fwds() {
 318         do_forward_fail_in_process_pending_htlc_fwds(ProcessPendingHTLCsCheck::FwdPeerDisconnected);
 319         do_forward_fail_in_process_pending_htlc_fwds(ProcessPendingHTLCsCheck::FwdChannelClosed);
 320 }
 321 fn do_forward_fail_in_process_pending_htlc_fwds(check: ProcessPendingHTLCsCheck) {
 322         // Ensure the intro node will error backwards properly if the HTLC fails in
 323         // process_pending_htlc_forwards.
 324         let chanmon_cfgs = create_chanmon_cfgs(3);
 325         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 326         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 327         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 328         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 329         let (chan_upd_1_2, channel_id) = {
 330                 let chan = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
 331                 (chan.0.contents, chan.2)
 332         };
 333
 334         let amt_msat = 5000;
 335         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
 336         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 337                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
 338                 &chanmon_cfgs[2].keys_manager);
 339
 340         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 341         check_added_monitors(&nodes[0], 1);
 342
 343         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 344         assert_eq!(events.len(), 1);
 345         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
 346         let mut payment_event = SendEvent::from_event(ev);
 347
 348         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 349         check_added_monitors!(nodes[1], 0);
 350         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, false, false);
 351
 352         match check {
 353                 ProcessPendingHTLCsCheck::FwdPeerDisconnected => {
 354                         // Disconnect the next-hop peer so when we go to forward in process_pending_htlc_forwards, the
 355                         // intro node will error backwards.
 356                         nodes[1].node.peer_disconnected(&nodes[2].node.get_our_node_id());
 357                         expect_pending_htlcs_forwardable!(nodes[1]);
 358                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1],
 359                                 vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id }]);
 360                 },
 361                 ProcessPendingHTLCsCheck::FwdChannelClosed => {
 362                         // Force close the next-hop channel so when we go to forward in process_pending_htlc_forwards,
 363                         // the intro node will error backwards.
 364                         nodes[1].node.force_close_broadcasting_latest_txn(&channel_id, &nodes[2].node.get_our_node_id()).unwrap();
 365                         let events = nodes[1].node.get_and_clear_pending_events();
 366                         match events[0] {
 367                                 crate::events::Event::PendingHTLCsForwardable { .. } => {},
 368                                 _ => panic!("Unexpected event {:?}", events),
 369                         };
 370                         match events[1] {
 371                                 crate::events::Event::ChannelClosed { .. } => {},
 372                                 _ => panic!("Unexpected event {:?}", events),
 373                         }
 374
 375                         nodes[1].node.process_pending_htlc_forwards();
 376                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1],
 377                                 vec![HTLCDestination::UnknownNextHop { requested_forward_scid: chan_upd_1_2.short_channel_id }]);
 378                         check_closed_broadcast(&nodes[1], 1, true);
 379                         check_added_monitors!(nodes[1], 1);
 380                         nodes[1].node.process_pending_htlc_forwards();
 381                 },
 382         }
 383
 384         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 385         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
 386         check_added_monitors!(nodes[1], 1);
 387         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
 388
 389         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
 390                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
 391 }
 392
 393 #[test]
 394 fn blinded_intercept_payment() {
 395         do_blinded_intercept_payment(true);
 396         do_blinded_intercept_payment(false);
 397 }
 398 fn do_blinded_intercept_payment(intercept_node_fails: bool) {
 399         let chanmon_cfgs = create_chanmon_cfgs(3);
 400         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 401         let mut intercept_forwards_config = test_default_channel_config();
 402         intercept_forwards_config.accept_intercept_htlcs = true;
 403         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, Some(intercept_forwards_config), None]);
 404         let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 405         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 406         let (channel_id, chan_upd) = {
 407                 let chan = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
 408                 (chan.2, chan.0.contents)
 409         };
 410
 411         let amt_msat = 5000;
 412         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
 413         let intercept_scid = nodes[1].node.get_intercept_scid();
 414         let mut intercept_chan_upd = chan_upd;
 415         intercept_chan_upd.short_channel_id = intercept_scid;
 416         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 417                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&intercept_chan_upd],
 418                 &chanmon_cfgs[2].keys_manager);
 419
 420         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
 421         PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 422         check_added_monitors(&nodes[0], 1);
 423         let payment_event = {
 424                 let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 425                 assert_eq!(events.len(), 1);
 426                 SendEvent::from_event(events.remove(0))
 427         };
 428         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 429         commitment_signed_dance!(nodes[1], nodes[0], &payment_event.commitment_msg, false, true);
 430
 431         let events = nodes[1].node.get_and_clear_pending_events();
 432         assert_eq!(events.len(), 1);
 433         let (intercept_id, expected_outbound_amount_msat) = match events[0] {
 434                 crate::events::Event::HTLCIntercepted {
 435                         intercept_id, payment_hash: pmt_hash,
 436                         requested_next_hop_scid: short_channel_id, expected_outbound_amount_msat, ..
 437                 } => {
 438                         assert_eq!(pmt_hash, payment_hash);
 439                         assert_eq!(short_channel_id, intercept_scid);
 440                         (intercept_id, expected_outbound_amount_msat)
 441                 },
 442                 _ => panic!()
 443         };
 444
 445         if intercept_node_fails {
 446                 nodes[1].node.fail_intercepted_htlc(intercept_id).unwrap();
 447                 expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1], vec![HTLCDestination::UnknownNextHop { requested_forward_scid: intercept_scid }]);
 448                 nodes[1].node.process_pending_htlc_forwards();
 449                 let update_fail = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 450                 check_added_monitors!(&nodes[1], 1);
 451                 assert!(update_fail.update_fail_htlcs.len() == 1);
 452                 let fail_msg = update_fail.update_fail_htlcs[0].clone();
 453                 nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
 454                 commitment_signed_dance!(nodes[0], nodes[1], update_fail.commitment_signed, false);
 455                 expect_payment_failed_conditions(&nodes[0], payment_hash, false,
 456                         PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
 457                 return
 458         }
 459
 460         nodes[1].node.forward_intercepted_htlc(intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap();
 461         expect_pending_htlcs_forwardable!(nodes[1]);
 462
 463         let payment_event = {
 464                 {
 465                         let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 466                         assert_eq!(added_monitors.len(), 1);
 467                         added_monitors.clear();
 468                 }
 469                 let mut events = nodes[1].node.get_and_clear_pending_msg_events();
 470                 assert_eq!(events.len(), 1);
 471                 SendEvent::from_event(events.remove(0))
 472         };
 473         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
 474         commitment_signed_dance!(nodes[2], nodes[1], &payment_event.commitment_msg, false, true);
 475         expect_pending_htlcs_forwardable!(nodes[2]);
 476
 477         expect_payment_claimable!(&nodes[2], payment_hash, payment_secret, amt_msat, None, nodes[2].node.get_our_node_id());
 478         do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[1], &nodes[2])[..]), false, payment_preimage);
 479         expect_payment_sent(&nodes[0], payment_preimage, Some(Some(1000)), true, true);
 480 }
 481
 482 #[test]
 483 fn two_hop_blinded_path_success() {
 484         let chanmon_cfgs = create_chanmon_cfgs(3);
 485         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 486         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 487         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 488         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 489         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
 490
 491         let amt_msat = 5000;
 492         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
 493         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 494                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
 495                 &chanmon_cfgs[2].keys_manager);
 496
 497         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 498         check_added_monitors(&nodes[0], 1);
 499         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2]]], amt_msat, payment_hash, payment_secret);
 500         claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], payment_preimage);
 501 }
 502
 503 #[test]
 504 fn three_hop_blinded_path_success() {
 505         let chanmon_cfgs = create_chanmon_cfgs(5);
 506         let node_cfgs = create_node_cfgs(5, &chanmon_cfgs);
 507         let node_chanmgrs = create_node_chanmgrs(5, &node_cfgs, &[None, None, None, None, None]);
 508         let mut nodes = create_network(5, &node_cfgs, &node_chanmgrs);
 509         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 510         create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
 511         let chan_upd_2_3 = create_announced_chan_between_nodes_with_value(&nodes, 2, 3, 1_000_000, 0).0.contents;
 512         let chan_upd_3_4 = create_announced_chan_between_nodes_with_value(&nodes, 3, 4, 1_000_000, 0).0.contents;
 513
 514         // Get all our nodes onto the same height so payments don't fail for CLTV violations.
 515         connect_blocks(&nodes[0], nodes[4].best_block_info().1 - nodes[0].best_block_info().1);
 516         connect_blocks(&nodes[1], nodes[4].best_block_info().1 - nodes[1].best_block_info().1);
 517         connect_blocks(&nodes[2], nodes[4].best_block_info().1 - nodes[2].best_block_info().1);
 518         assert_eq!(nodes[4].best_block_info().1, nodes[3].best_block_info().1);
 519
 520         let amt_msat = 5000;
 521         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[4], Some(amt_msat), None);
 522         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 523                 nodes.iter().skip(2).map(|n| n.node.get_our_node_id()).collect(),
 524                 &[&chan_upd_2_3, &chan_upd_3_4], &chanmon_cfgs[4].keys_manager);
 525
 526         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 527         check_added_monitors(&nodes[0], 1);
 528         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2], &nodes[3], &nodes[4]]], amt_msat, payment_hash, payment_secret);
 529         claim_payment(&nodes[0], &[&nodes[1], &nodes[2], &nodes[3], &nodes[4]], payment_preimage);
 530 }
 531
 532 #[derive(PartialEq)]
 533 enum ReceiveCheckFail {
 534         // The recipient fails the payment upon `PaymentClaimable`.
 535         RecipientFail,
 536         // Failure to decode the recipient's onion payload.
 537         OnionDecodeFail,
 538         // The incoming HTLC did not satisfy our requirements; in this case it underpaid us according to
 539         // the expected receive amount in the onion.
 540         ReceiveRequirements,
 541         // The incoming HTLC errors when added to the Channel, in this case due to the HTLC being
 542         // delivered out-of-order with a shutdown message.
 543         ChannelCheck,
 544         // The HTLC is successfully added to the inbound channel but fails receive checks in
 545         // process_pending_htlc_forwards.
 546         ProcessPendingHTLCsCheck,
 547         // The HTLC violates the `PaymentConstraints` contained within the receiver's encrypted payload.
 548         PaymentConstraints,
 549 }
 550
 551 #[test]
 552 fn multi_hop_receiver_fail() {
 553         do_multi_hop_receiver_fail(ReceiveCheckFail::RecipientFail);
 554         do_multi_hop_receiver_fail(ReceiveCheckFail::OnionDecodeFail);
 555         do_multi_hop_receiver_fail(ReceiveCheckFail::ReceiveRequirements);
 556         do_multi_hop_receiver_fail(ReceiveCheckFail::ChannelCheck);
 557         do_multi_hop_receiver_fail(ReceiveCheckFail::ProcessPendingHTLCsCheck);
 558         do_multi_hop_receiver_fail(ReceiveCheckFail::PaymentConstraints);
 559 }
 560
 561 fn do_multi_hop_receiver_fail(check: ReceiveCheckFail) {
 562         // Test that the receiver to a multihop blinded path fails back correctly.
 563         let chanmon_cfgs = create_chanmon_cfgs(3);
 564         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 565         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 566         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 567         // We need the session priv to construct an invalid onion packet later.
 568         let session_priv = [3; 32];
 569         *nodes[0].keys_manager.override_random_bytes.lock().unwrap() = Some(session_priv);
 570         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 571         let (chan_upd_1_2, chan_id_1_2) = {
 572                 let (chan_upd, _, channel_id, ..) = create_announced_chan_between_nodes_with_value(
 573                         &nodes, 1, 2, 1_000_000, 0
 574                 );
 575                 (chan_upd.contents, channel_id)
 576         };
 577
 578         let amt_msat = 5000;
 579         let excess_final_cltv_delta_opt = if check == ReceiveCheckFail::ProcessPendingHTLCsCheck {
 580                 // Set the final CLTV expiry too low to trigger the failure in process_pending_htlc_forwards.
 581                 Some(TEST_FINAL_CLTV as u16 - 2)
 582         } else { None };
 583         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), excess_final_cltv_delta_opt);
 584         let mut route_params = get_blinded_route_parameters(amt_msat, payment_secret,
 585                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
 586                 &chanmon_cfgs[2].keys_manager);
 587
 588         let route = if check == ReceiveCheckFail::ProcessPendingHTLCsCheck {
 589                 let mut route = get_route(&nodes[0], &route_params).unwrap();
 590                 // Set the final CLTV expiry too low to trigger the failure in process_pending_htlc_forwards.
 591                 route.paths[0].hops.last_mut().map(|h| h.cltv_expiry_delta += excess_final_cltv_delta_opt.unwrap() as u32);
 592                 route.paths[0].blinded_tail.as_mut().map(|bt| bt.excess_final_cltv_expiry_delta = excess_final_cltv_delta_opt.unwrap() as u32);
 593                 route
 594         } else if check == ReceiveCheckFail::PaymentConstraints {
 595                 // Create a blinded path where the receiver's encrypted payload has an htlc_minimum_msat that is
 596                 // violated by `amt_msat`, and stick it in the route_params without changing the corresponding
 597                 // BlindedPayInfo (to ensure pathfinding still succeeds).
 598                 let high_htlc_min_bp = {
 599                         let mut high_htlc_minimum_upd = chan_upd_1_2.clone();
 600                         high_htlc_minimum_upd.htlc_minimum_msat = amt_msat + 1000;
 601                         let high_htlc_min_params = get_blinded_route_parameters(amt_msat, payment_secret,
 602                                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&high_htlc_minimum_upd],
 603                                 &chanmon_cfgs[2].keys_manager);
 604                         if let Payee::Blinded { route_hints, .. } = high_htlc_min_params.payment_params.payee {
 605                                 route_hints[0].1.clone()
 606                         } else { panic!() }
 607                 };
 608                 if let Payee::Blinded { ref mut route_hints, .. } = route_params.payment_params.payee {
 609                         route_hints[0].1 = high_htlc_min_bp;
 610                 } else { panic!() }
 611                 find_route(&nodes[0], &route_params).unwrap()
 612         } else {
 613                 find_route(&nodes[0], &route_params).unwrap()
 614         };
 615         node_cfgs[0].router.expect_find_route(route_params.clone(), Ok(route.clone()));
 616         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
 617         check_added_monitors(&nodes[0], 1);
 618
 619         let mut payment_event_0_1 = {
 620                 let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 621                 assert_eq!(events.len(), 1);
 622                 let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
 623                 SendEvent::from_event(ev)
 624         };
 625         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event_0_1.msgs[0]);
 626         check_added_monitors!(nodes[1], 0);
 627         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event_0_1.commitment_msg, false, false);
 628         expect_pending_htlcs_forwardable!(nodes[1]);
 629         check_added_monitors!(&nodes[1], 1);
 630
 631         let mut payment_event_1_2 = {
 632                 let mut events = nodes[1].node.get_and_clear_pending_msg_events();
 633                 assert_eq!(events.len(), 1);
 634                 let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
 635                 SendEvent::from_event(ev)
 636         };
 637
 638         match check {
 639                 ReceiveCheckFail::RecipientFail => {
 640                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
 641                         check_added_monitors!(nodes[2], 0);
 642                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
 643                         expect_pending_htlcs_forwardable!(nodes[2]);
 644                         check_payment_claimable(
 645                                 &nodes[2].node.get_and_clear_pending_events()[0], payment_hash, payment_secret, amt_msat,
 646                                 None, nodes[2].node.get_our_node_id()
 647                         );
 648                         nodes[2].node.fail_htlc_backwards(&payment_hash);
 649                         expect_pending_htlcs_forwardable_conditions(
 650                                 nodes[2].node.get_and_clear_pending_events(), &[HTLCDestination::FailedPayment { payment_hash }]
 651                         );
 652                         nodes[2].node.process_pending_htlc_forwards();
 653                         check_added_monitors!(nodes[2], 1);
 654                 },
 655                 ReceiveCheckFail::OnionDecodeFail => {
 656                         let session_priv = SecretKey::from_slice(&session_priv).unwrap();
 657                         let mut onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
 658                         let cur_height = nodes[0].best_block_info().1;
 659                         let (mut onion_payloads, ..) = onion_utils::build_onion_payloads(
 660                                 &route.paths[0], amt_msat, RecipientOnionFields::spontaneous_empty(), cur_height, &None).unwrap();
 661
 662                         let update_add = &mut payment_event_1_2.msgs[0];
 663                         onion_payloads.last_mut().map(|p| {
 664                                 if let msgs::OutboundOnionPayload::BlindedReceive { ref mut intro_node_blinding_point, .. } = p {
 665                                         // The receiver should error if both the update_add blinding_point and the
 666                                         // intro_node_blinding_point are set.
 667                                         assert!(intro_node_blinding_point.is_none() && update_add.blinding_point.is_some());
 668                                         *intro_node_blinding_point = Some(PublicKey::from_slice(&[2; 33]).unwrap());
 669                                 } else { panic!() }
 670                         });
 671                         update_add.onion_routing_packet = onion_utils::construct_onion_packet(
 672                                 vec![onion_payloads.pop().unwrap()], vec![onion_keys.pop().unwrap()], [0; 32],
 673                                 &payment_hash
 674                         ).unwrap();
 675                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), update_add);
 676                         check_added_monitors!(nodes[2], 0);
 677                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
 678                 },
 679                 ReceiveCheckFail::ReceiveRequirements => {
 680                         let update_add = &mut payment_event_1_2.msgs[0];
 681                         update_add.amount_msat -= 1;
 682                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), update_add);
 683                         check_added_monitors!(nodes[2], 0);
 684                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
 685                 },
 686                 ReceiveCheckFail::ChannelCheck => {
 687                         nodes[2].node.close_channel(&chan_id_1_2, &nodes[1].node.get_our_node_id()).unwrap();
 688                         let node_2_shutdown = get_event_msg!(nodes[2], MessageSendEvent::SendShutdown, nodes[1].node.get_our_node_id());
 689                         nodes[1].node.handle_shutdown(&nodes[2].node.get_our_node_id(), &node_2_shutdown);
 690                         let node_1_shutdown = get_event_msg!(nodes[1], MessageSendEvent::SendShutdown, nodes[2].node.get_our_node_id());
 691
 692                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
 693                         nodes[2].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &payment_event_1_2.commitment_msg);
 694                         check_added_monitors!(nodes[2], 1);
 695
 696                         nodes[2].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &node_1_shutdown);
 697                         commitment_signed_dance!(nodes[2], nodes[1], (), false, true, false, false);
 698                 },
 699                 ReceiveCheckFail::ProcessPendingHTLCsCheck => {
 700                         assert_eq!(payment_event_1_2.msgs[0].cltv_expiry, nodes[0].best_block_info().1 + 1 + excess_final_cltv_delta_opt.unwrap() as u32 + TEST_FINAL_CLTV);
 701                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
 702                         check_added_monitors!(nodes[2], 0);
 703                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
 704                         expect_pending_htlcs_forwardable!(nodes[2]);
 705                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[2],
 706                                 vec![HTLCDestination::FailedPayment { payment_hash }]);
 707                         check_added_monitors!(nodes[2], 1);
 708                 },
 709                 ReceiveCheckFail::PaymentConstraints => {
 710                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
 711                         check_added_monitors!(nodes[2], 0);
 712                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
 713                 }
 714         }
 715
 716         let updates_2_1 = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
 717         assert_eq!(updates_2_1.update_fail_malformed_htlcs.len(), 1);
 718         let update_malformed = &updates_2_1.update_fail_malformed_htlcs[0];
 719         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
 720         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
 721         nodes[1].node.handle_update_fail_malformed_htlc(&nodes[2].node.get_our_node_id(), update_malformed);
 722         do_commitment_signed_dance(&nodes[1], &nodes[2], &updates_2_1.commitment_signed, true, false);
 723
 724         let updates_1_0 = if check == ReceiveCheckFail::ChannelCheck {
 725                 let events = nodes[1].node.get_and_clear_pending_msg_events();
 726                 assert_eq!(events.len(), 2);
 727                 events.into_iter().find_map(|ev| {
 728                         match ev {
 729                                 MessageSendEvent:: UpdateHTLCs { node_id, updates } => {
 730                                         assert_eq!(node_id, nodes[0].node.get_our_node_id());
 731                                         return Some(updates)
 732                                 },
 733                                 MessageSendEvent::SendClosingSigned { .. } => None,
 734                                 _ => panic!()
 735                         }
 736                 }).unwrap()
 737         } else { get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id()) };
 738         assert_eq!(updates_1_0.update_fail_htlcs.len(), 1);
 739         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates_1_0.update_fail_htlcs[0]);
 740         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates_1_0.commitment_signed, false, false);
 741         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
 742                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
 743 }
 744
 745 #[test]
 746 fn blinded_path_retries() {
 747         let chanmon_cfgs = create_chanmon_cfgs(4);
 748         // Make one blinded path's fees slightly higher so they are tried in a deterministic order.
 749         let mut higher_fee_chan_cfg = test_default_channel_config();
 750         higher_fee_chan_cfg.channel_config.forwarding_fee_base_msat += 1;
 751         let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
 752         let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, Some(higher_fee_chan_cfg), None]);
 753         let mut nodes = create_network(4, &node_cfgs, &node_chanmgrs);
 754
 755         // Create this network topology so nodes[0] has a blinded route hint to retry over.
 756         //      n1
 757         //    /    \
 758         // n0       n3
 759         //    \    /
 760         //      n2
 761         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 762         create_announced_chan_between_nodes_with_value(&nodes, 0, 2, 1_000_000, 0);
 763         let chan_1_3 = create_announced_chan_between_nodes_with_value(&nodes, 1, 3, 1_000_000, 0);
 764         let chan_2_3 = create_announced_chan_between_nodes_with_value(&nodes, 2, 3, 1_000_000, 0);
 765
 766         let amt_msat = 5000;
 767         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[3], Some(amt_msat), None);
 768         let route_params = {
 769                 let pay_params = PaymentParameters::blinded(
 770                         vec![
 771                                 blinded_payment_path(payment_secret,
 772                                         vec![nodes[1].node.get_our_node_id(), nodes[3].node.get_our_node_id()], &[&chan_1_3.0.contents],
 773                                         &chanmon_cfgs[3].keys_manager
 774                                 ),
 775                                 blinded_payment_path(payment_secret,
 776                                         vec![nodes[2].node.get_our_node_id(), nodes[3].node.get_our_node_id()], &[&chan_2_3.0.contents],
 777                                         &chanmon_cfgs[3].keys_manager
 778                                 ),
 779                         ]
 780                 )
 781                         .with_bolt12_features(channelmanager::provided_bolt12_invoice_features(&UserConfig::default()))
 782                         .unwrap();
 783                 RouteParameters::from_payment_params_and_value(pay_params, amt_msat)
 784         };
 785
 786         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params.clone(), Retry::Attempts(2)).unwrap();
 787         check_added_monitors(&nodes[0], 1);
 788         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[3]]], amt_msat, payment_hash, payment_secret);
 789
 790         macro_rules! fail_payment_back {
 791                 ($intro_node: expr) => {
 792                         nodes[3].node.fail_htlc_backwards(&payment_hash);
 793                         expect_pending_htlcs_forwardable_conditions(
 794                                 nodes[3].node.get_and_clear_pending_events(), &[HTLCDestination::FailedPayment { payment_hash }]
 795                         );
 796                         nodes[3].node.process_pending_htlc_forwards();
 797                         check_added_monitors!(nodes[3], 1);
 798
 799                         let updates = get_htlc_update_msgs!(nodes[3], $intro_node.node.get_our_node_id());
 800                         assert_eq!(updates.update_fail_malformed_htlcs.len(), 1);
 801                         let update_malformed = &updates.update_fail_malformed_htlcs[0];
 802                         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
 803                         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
 804                         $intro_node.node.handle_update_fail_malformed_htlc(&nodes[3].node.get_our_node_id(), update_malformed);
 805                         do_commitment_signed_dance(&$intro_node, &nodes[3], &updates.commitment_signed, true, false);
 806
 807                         let updates =  get_htlc_update_msgs!($intro_node, nodes[0].node.get_our_node_id());
 808                         assert_eq!(updates.update_fail_htlcs.len(), 1);
 809                         nodes[0].node.handle_update_fail_htlc(&$intro_node.node.get_our_node_id(), &updates.update_fail_htlcs[0]);
 810                         do_commitment_signed_dance(&nodes[0], &$intro_node, &updates.commitment_signed, false, false);
 811
 812                         let mut events = nodes[0].node.get_and_clear_pending_events();
 813                         assert_eq!(events.len(), 2);
 814                         match events[0] {
 815                                 Event::PaymentPathFailed { payment_hash: ev_payment_hash, payment_failed_permanently, ..  } => {
 816                                         assert_eq!(payment_hash, ev_payment_hash);
 817                                         assert_eq!(payment_failed_permanently, false);
 818                                 },
 819                                 _ => panic!("Unexpected event"),
 820                         }
 821                         match events[1] {
 822                                 Event::PendingHTLCsForwardable { .. } => {},
 823                                 _ => panic!("Unexpected event"),
 824                         }
 825                         nodes[0].node.process_pending_htlc_forwards();
 826                 }
 827         }
 828
 829         fail_payment_back!(nodes[1]);
 830
 831         // Pass the retry along.
 832         check_added_monitors!(nodes[0], 1);
 833         let mut msg_events = nodes[0].node.get_and_clear_pending_msg_events();
 834         assert_eq!(msg_events.len(), 1);
 835         pass_along_path(&nodes[0], &[&nodes[2], &nodes[3]], amt_msat, payment_hash, Some(payment_secret), msg_events.pop().unwrap(), true, None);
 836
 837         fail_payment_back!(nodes[2]);
 838         let evs = nodes[0].node.get_and_clear_pending_events();
 839         assert_eq!(evs.len(), 1);
 840         match evs[0] {
 841                 Event::PaymentFailed { payment_hash: ev_payment_hash, reason, .. } => {
 842                         assert_eq!(ev_payment_hash, payment_hash);
 843                         // We have 1 retry attempt remaining, but we're out of blinded paths to try.
 844                         assert_eq!(reason, Some(PaymentFailureReason::RouteNotFound));
 845                 },
 846                 _ => panic!()
 847         }
 848 }