Merge pull request #2878 from TheBlueMatt/2024-02-fix-build
[rust-lightning] / 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, 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, &chanmon_cfgs[1].keys_manager, &secp_ctx
104         ).unwrap();
105
106         let route_params = RouteParameters::from_payment_params_and_value(
107                 PaymentParameters::blinded(vec![blinded_path]),
108                 amt_msat,
109         );
110         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
111         PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
112         check_added_monitors(&nodes[0], 1);
113         pass_along_route(&nodes[0], &[&[&nodes[1]]], amt_msat, payment_hash, payment_secret);
114         if success {
115                 claim_payment(&nodes[0], &[&nodes[1]], payment_preimage);
116         } else {
117                 fail_payment(&nodes[0], &[&nodes[1]], payment_hash);
118         }
119 }
120
121 #[test]
122 fn mpp_to_one_hop_blinded_path() {
123         let chanmon_cfgs = create_chanmon_cfgs(4);
124         let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
125         let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
126         let nodes = create_network(4, &node_cfgs, &node_chanmgrs);
127         let mut secp_ctx = Secp256k1::new();
128
129         create_announced_chan_between_nodes(&nodes, 0, 1);
130         create_announced_chan_between_nodes(&nodes, 0, 2);
131         let chan_upd_1_3 = create_announced_chan_between_nodes(&nodes, 1, 3).0.contents;
132         create_announced_chan_between_nodes(&nodes, 2, 3).0.contents;
133
134         let amt_msat = 15_000_000;
135         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[3], Some(amt_msat), None);
136         let payee_tlvs = ReceiveTlvs {
137                 payment_secret,
138                 payment_constraints: PaymentConstraints {
139                         max_cltv_expiry: u32::max_value(),
140                         htlc_minimum_msat: chan_upd_1_3.htlc_minimum_msat,
141                 },
142         };
143         let blinded_path = BlindedPath::one_hop_for_payment(
144                 nodes[3].node.get_our_node_id(), payee_tlvs, &chanmon_cfgs[3].keys_manager, &secp_ctx
145         ).unwrap();
146
147         let bolt12_features =
148                 channelmanager::provided_bolt12_invoice_features(&UserConfig::default());
149         let route_params = RouteParameters::from_payment_params_and_value(
150                 PaymentParameters::blinded(vec![blinded_path]).with_bolt12_features(bolt12_features).unwrap(),
151                 amt_msat,
152         );
153         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
154         check_added_monitors(&nodes[0], 2);
155
156         let expected_route: &[&[&Node]] = &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]];
157         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
158         assert_eq!(events.len(), 2);
159
160         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
161         pass_along_path(&nodes[0], expected_route[0], amt_msat, payment_hash.clone(),
162                 Some(payment_secret), ev.clone(), false, None);
163
164         let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
165         pass_along_path(&nodes[0], expected_route[1], amt_msat, payment_hash.clone(),
166                 Some(payment_secret), ev.clone(), true, None);
167         claim_payment_along_route(&nodes[0], expected_route, false, payment_preimage);
168 }
169
170 enum ForwardCheckFail {
171         // Fail a check on the inbound onion payload. In this case, we underflow when calculating the
172         // outgoing cltv_expiry.
173         InboundOnionCheck,
174         // The forwarding node's payload is encoded as a receive, i.e. the next hop HMAC is [0; 32].
175         ForwardPayloadEncodedAsReceive,
176         // Fail a check on the outbound channel. In this case, our next-hop peer is offline.
177         OutboundChannelCheck,
178 }
179
180 #[test]
181 fn forward_checks_failure() {
182         do_forward_checks_failure(ForwardCheckFail::InboundOnionCheck);
183         do_forward_checks_failure(ForwardCheckFail::ForwardPayloadEncodedAsReceive);
184         do_forward_checks_failure(ForwardCheckFail::OutboundChannelCheck);
185 }
186
187 fn do_forward_checks_failure(check: ForwardCheckFail) {
188         // Ensure we'll fail backwards properly if a forwarding check fails on initial update_add
189         // receipt.
190         let chanmon_cfgs = create_chanmon_cfgs(3);
191         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
192         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
193         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
194         // We need the session priv to construct a bogus onion packet later.
195         *nodes[0].keys_manager.override_random_bytes.lock().unwrap() = Some([3; 32]);
196         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
197         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
198
199         let amt_msat = 5000;
200         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
201         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
202                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
203                 &chanmon_cfgs[2].keys_manager);
204
205         let route = get_route(&nodes[0], &route_params).unwrap();
206         node_cfgs[0].router.expect_find_route(route_params.clone(), Ok(route.clone()));
207         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
208         check_added_monitors(&nodes[0], 1);
209
210         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
211         assert_eq!(events.len(), 1);
212         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
213         let mut payment_event = SendEvent::from_event(ev);
214
215         let mut update_add = &mut payment_event.msgs[0];
216         match check {
217                 ForwardCheckFail::InboundOnionCheck => {
218                         update_add.cltv_expiry = 10; // causes outbound CLTV expiry to underflow
219                 },
220                 ForwardCheckFail::ForwardPayloadEncodedAsReceive => {
221                         let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
222                         let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
223                         let cur_height = nodes[0].best_block_info().1;
224                         let (mut onion_payloads, ..) = onion_utils::build_onion_payloads(
225                                 &route.paths[0], amt_msat, RecipientOnionFields::spontaneous_empty(), cur_height, &None).unwrap();
226                         // Remove the receive payload so the blinded forward payload is encoded as a final payload
227                         // (i.e. next_hop_hmac == [0; 32])
228                         onion_payloads.pop();
229                         update_add.onion_routing_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &payment_hash).unwrap();
230                 },
231                 ForwardCheckFail::OutboundChannelCheck => {
232                         // The intro node will see that the next-hop peer is disconnected and fail the HTLC backwards.
233                         nodes[1].node.peer_disconnected(&nodes[2].node.get_our_node_id());
234                 },
235         }
236         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
237         check_added_monitors!(nodes[1], 0);
238         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, true, true);
239
240         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
241         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
242         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
243         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
244                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
245 }
246
247 #[test]
248 fn failed_backwards_to_intro_node() {
249         // Ensure the intro node will error backwards properly even if the downstream node did not blind
250         // their error.
251         let chanmon_cfgs = create_chanmon_cfgs(3);
252         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
253         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
254         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
255         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
256         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
257
258         let amt_msat = 5000;
259         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
260         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
261                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
262                 &chanmon_cfgs[2].keys_manager);
263
264         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
265         check_added_monitors(&nodes[0], 1);
266
267         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
268         assert_eq!(events.len(), 1);
269         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
270         let mut payment_event = SendEvent::from_event(ev);
271
272         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
273         check_added_monitors!(nodes[1], 0);
274         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, false, false);
275         expect_pending_htlcs_forwardable!(nodes[1]);
276         check_added_monitors!(&nodes[1], 1);
277
278         let mut events = nodes[1].node.get_and_clear_pending_msg_events();
279         assert_eq!(events.len(), 1);
280         let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
281         let mut payment_event = SendEvent::from_event(ev);
282
283         // Ensure the final node fails to handle the HTLC.
284         payment_event.msgs[0].onion_routing_packet.hop_data[0] ^= 1;
285         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
286         check_added_monitors!(nodes[2], 0);
287         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event.commitment_msg, true, true);
288         nodes[2].node.process_pending_htlc_forwards();
289
290         let mut updates = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
291         let mut update_malformed = &mut updates.update_fail_malformed_htlcs[0];
292         // Check that the final node encodes its failure correctly.
293         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
294         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
295
296         // Modify such the final hop does not correctly blind their error so we can ensure the intro node
297         // converts it to the correct error.
298         update_malformed.sha256_of_onion = [1; 32];
299         nodes[1].node.handle_update_fail_malformed_htlc(&nodes[2].node.get_our_node_id(), update_malformed);
300         do_commitment_signed_dance(&nodes[1], &nodes[2], &updates.commitment_signed, true, false);
301
302         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
303         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
304         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
305         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
306                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
307 }
308
309 enum ProcessPendingHTLCsCheck {
310         FwdPeerDisconnected,
311         FwdChannelClosed,
312 }
313
314 #[test]
315 fn forward_fail_in_process_pending_htlc_fwds() {
316         do_forward_fail_in_process_pending_htlc_fwds(ProcessPendingHTLCsCheck::FwdPeerDisconnected);
317         do_forward_fail_in_process_pending_htlc_fwds(ProcessPendingHTLCsCheck::FwdChannelClosed);
318 }
319 fn do_forward_fail_in_process_pending_htlc_fwds(check: ProcessPendingHTLCsCheck) {
320         // Ensure the intro node will error backwards properly if the HTLC fails in
321         // process_pending_htlc_forwards.
322         let chanmon_cfgs = create_chanmon_cfgs(3);
323         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
324         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
325         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
326         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
327         let (chan_upd_1_2, channel_id) = {
328                 let chan = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
329                 (chan.0.contents, chan.2)
330         };
331
332         let amt_msat = 5000;
333         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
334         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
335                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
336                 &chanmon_cfgs[2].keys_manager);
337
338         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
339         check_added_monitors(&nodes[0], 1);
340
341         let mut events = nodes[0].node.get_and_clear_pending_msg_events();
342         assert_eq!(events.len(), 1);
343         let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
344         let mut payment_event = SendEvent::from_event(ev);
345
346         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
347         check_added_monitors!(nodes[1], 0);
348         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event.commitment_msg, false, false);
349
350         match check {
351                 ProcessPendingHTLCsCheck::FwdPeerDisconnected => {
352                         // Disconnect the next-hop peer so when we go to forward in process_pending_htlc_forwards, the
353                         // intro node will error backwards.
354                         nodes[1].node.peer_disconnected(&nodes[2].node.get_our_node_id());
355                         expect_pending_htlcs_forwardable!(nodes[1]);
356                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1],
357                                 vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id }]);
358                 },
359                 ProcessPendingHTLCsCheck::FwdChannelClosed => {
360                         // Force close the next-hop channel so when we go to forward in process_pending_htlc_forwards,
361                         // the intro node will error backwards.
362                         nodes[1].node.force_close_broadcasting_latest_txn(&channel_id, &nodes[2].node.get_our_node_id()).unwrap();
363                         let events = nodes[1].node.get_and_clear_pending_events();
364                         match events[0] {
365                                 crate::events::Event::PendingHTLCsForwardable { .. } => {},
366                                 _ => panic!("Unexpected event {:?}", events),
367                         };
368                         match events[1] {
369                                 crate::events::Event::ChannelClosed { .. } => {},
370                                 _ => panic!("Unexpected event {:?}", events),
371                         }
372
373                         nodes[1].node.process_pending_htlc_forwards();
374                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1],
375                                 vec![HTLCDestination::UnknownNextHop { requested_forward_scid: chan_upd_1_2.short_channel_id }]);
376                         check_closed_broadcast(&nodes[1], 1, true);
377                         check_added_monitors!(nodes[1], 1);
378                         nodes[1].node.process_pending_htlc_forwards();
379                 },
380         }
381
382         let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
383         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
384         check_added_monitors!(nodes[1], 1);
385         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
386
387         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
388                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
389 }
390
391 #[test]
392 fn blinded_intercept_payment() {
393         do_blinded_intercept_payment(true);
394         do_blinded_intercept_payment(false);
395 }
396 fn do_blinded_intercept_payment(intercept_node_fails: bool) {
397         let chanmon_cfgs = create_chanmon_cfgs(3);
398         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
399         let mut intercept_forwards_config = test_default_channel_config();
400         intercept_forwards_config.accept_intercept_htlcs = true;
401         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, Some(intercept_forwards_config), None]);
402         let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
403         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
404         let (channel_id, chan_upd) = {
405                 let chan = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
406                 (chan.2, chan.0.contents)
407         };
408
409         let amt_msat = 5000;
410         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
411         let intercept_scid = nodes[1].node.get_intercept_scid();
412         let mut intercept_chan_upd = chan_upd;
413         intercept_chan_upd.short_channel_id = intercept_scid;
414         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
415                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&intercept_chan_upd],
416                 &chanmon_cfgs[2].keys_manager);
417
418         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
419         PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
420         check_added_monitors(&nodes[0], 1);
421         let payment_event = {
422                 let mut events = nodes[0].node.get_and_clear_pending_msg_events();
423                 assert_eq!(events.len(), 1);
424                 SendEvent::from_event(events.remove(0))
425         };
426         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
427         commitment_signed_dance!(nodes[1], nodes[0], &payment_event.commitment_msg, false, true);
428
429         let events = nodes[1].node.get_and_clear_pending_events();
430         assert_eq!(events.len(), 1);
431         let (intercept_id, expected_outbound_amount_msat) = match events[0] {
432                 crate::events::Event::HTLCIntercepted {
433                         intercept_id, payment_hash: pmt_hash,
434                         requested_next_hop_scid: short_channel_id, expected_outbound_amount_msat, ..
435                 } => {
436                         assert_eq!(pmt_hash, payment_hash);
437                         assert_eq!(short_channel_id, intercept_scid);
438                         (intercept_id, expected_outbound_amount_msat)
439                 },
440                 _ => panic!()
441         };
442
443         if intercept_node_fails {
444                 nodes[1].node.fail_intercepted_htlc(intercept_id).unwrap();
445                 expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1], vec![HTLCDestination::UnknownNextHop { requested_forward_scid: intercept_scid }]);
446                 nodes[1].node.process_pending_htlc_forwards();
447                 let update_fail = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
448                 check_added_monitors!(&nodes[1], 1);
449                 assert!(update_fail.update_fail_htlcs.len() == 1);
450                 let fail_msg = update_fail.update_fail_htlcs[0].clone();
451                 nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
452                 commitment_signed_dance!(nodes[0], nodes[1], update_fail.commitment_signed, false);
453                 expect_payment_failed_conditions(&nodes[0], payment_hash, false,
454                         PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
455                 return
456         }
457
458         nodes[1].node.forward_intercepted_htlc(intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap();
459         expect_pending_htlcs_forwardable!(nodes[1]);
460
461         let payment_event = {
462                 {
463                         let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
464                         assert_eq!(added_monitors.len(), 1);
465                         added_monitors.clear();
466                 }
467                 let mut events = nodes[1].node.get_and_clear_pending_msg_events();
468                 assert_eq!(events.len(), 1);
469                 SendEvent::from_event(events.remove(0))
470         };
471         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
472         commitment_signed_dance!(nodes[2], nodes[1], &payment_event.commitment_msg, false, true);
473         expect_pending_htlcs_forwardable!(nodes[2]);
474
475         expect_payment_claimable!(&nodes[2], payment_hash, payment_secret, amt_msat, None, nodes[2].node.get_our_node_id());
476         do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[1], &nodes[2])[..]), false, payment_preimage);
477         expect_payment_sent(&nodes[0], payment_preimage, Some(Some(1000)), true, true);
478 }
479
480 #[test]
481 fn two_hop_blinded_path_success() {
482         let chanmon_cfgs = create_chanmon_cfgs(3);
483         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
484         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
485         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
486         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
487         let chan_upd_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
488
489         let amt_msat = 5000;
490         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), None);
491         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
492                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
493                 &chanmon_cfgs[2].keys_manager);
494
495         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
496         check_added_monitors(&nodes[0], 1);
497         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2]]], amt_msat, payment_hash, payment_secret);
498         claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], payment_preimage);
499 }
500
501 #[test]
502 fn three_hop_blinded_path_success() {
503         let chanmon_cfgs = create_chanmon_cfgs(5);
504         let node_cfgs = create_node_cfgs(5, &chanmon_cfgs);
505         let node_chanmgrs = create_node_chanmgrs(5, &node_cfgs, &[None, None, None, None, None]);
506         let mut nodes = create_network(5, &node_cfgs, &node_chanmgrs);
507         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
508         create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
509         let chan_upd_2_3 = create_announced_chan_between_nodes_with_value(&nodes, 2, 3, 1_000_000, 0).0.contents;
510         let chan_upd_3_4 = create_announced_chan_between_nodes_with_value(&nodes, 3, 4, 1_000_000, 0).0.contents;
511
512         // Get all our nodes onto the same height so payments don't fail for CLTV violations.
513         connect_blocks(&nodes[0], nodes[4].best_block_info().1 - nodes[0].best_block_info().1);
514         connect_blocks(&nodes[1], nodes[4].best_block_info().1 - nodes[1].best_block_info().1);
515         connect_blocks(&nodes[2], nodes[4].best_block_info().1 - nodes[2].best_block_info().1);
516         assert_eq!(nodes[4].best_block_info().1, nodes[3].best_block_info().1);
517
518         let amt_msat = 5000;
519         let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[4], Some(amt_msat), None);
520         let route_params = get_blinded_route_parameters(amt_msat, payment_secret,
521                 nodes.iter().skip(2).map(|n| n.node.get_our_node_id()).collect(),
522                 &[&chan_upd_2_3, &chan_upd_3_4], &chanmon_cfgs[4].keys_manager);
523
524         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
525         check_added_monitors(&nodes[0], 1);
526         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2], &nodes[3], &nodes[4]]], amt_msat, payment_hash, payment_secret);
527         claim_payment(&nodes[0], &[&nodes[1], &nodes[2], &nodes[3], &nodes[4]], payment_preimage);
528 }
529
530 #[derive(PartialEq)]
531 enum ReceiveCheckFail {
532         // The recipient fails the payment upon `PaymentClaimable`.
533         RecipientFail,
534         // Failure to decode the recipient's onion payload.
535         OnionDecodeFail,
536         // The incoming HTLC did not satisfy our requirements; in this case it underpaid us according to
537         // the expected receive amount in the onion.
538         ReceiveRequirements,
539         // The incoming HTLC errors when added to the Channel, in this case due to the HTLC being
540         // delivered out-of-order with a shutdown message.
541         ChannelCheck,
542         // The HTLC is successfully added to the inbound channel but fails receive checks in
543         // process_pending_htlc_forwards.
544         ProcessPendingHTLCsCheck,
545         // The HTLC violates the `PaymentConstraints` contained within the receiver's encrypted payload.
546         PaymentConstraints,
547 }
548
549 #[test]
550 fn multi_hop_receiver_fail() {
551         do_multi_hop_receiver_fail(ReceiveCheckFail::RecipientFail);
552         do_multi_hop_receiver_fail(ReceiveCheckFail::OnionDecodeFail);
553         do_multi_hop_receiver_fail(ReceiveCheckFail::ReceiveRequirements);
554         do_multi_hop_receiver_fail(ReceiveCheckFail::ChannelCheck);
555         do_multi_hop_receiver_fail(ReceiveCheckFail::ProcessPendingHTLCsCheck);
556         do_multi_hop_receiver_fail(ReceiveCheckFail::PaymentConstraints);
557 }
558
559 fn do_multi_hop_receiver_fail(check: ReceiveCheckFail) {
560         // Test that the receiver to a multihop blinded path fails back correctly.
561         let chanmon_cfgs = create_chanmon_cfgs(3);
562         let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
563         let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
564         let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
565         // We need the session priv to construct an invalid onion packet later.
566         let session_priv = [3; 32];
567         *nodes[0].keys_manager.override_random_bytes.lock().unwrap() = Some(session_priv);
568         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
569         let (chan_upd_1_2, chan_id_1_2) = {
570                 let (chan_upd, _, channel_id, ..) = create_announced_chan_between_nodes_with_value(
571                         &nodes, 1, 2, 1_000_000, 0
572                 );
573                 (chan_upd.contents, channel_id)
574         };
575
576         let amt_msat = 5000;
577         let excess_final_cltv_delta_opt = if check == ReceiveCheckFail::ProcessPendingHTLCsCheck {
578                 // Set the final CLTV expiry too low to trigger the failure in process_pending_htlc_forwards.
579                 Some(TEST_FINAL_CLTV as u16 - 2)
580         } else { None };
581         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[2], Some(amt_msat), excess_final_cltv_delta_opt);
582         let mut route_params = get_blinded_route_parameters(amt_msat, payment_secret,
583                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&chan_upd_1_2],
584                 &chanmon_cfgs[2].keys_manager);
585
586         let route = if check == ReceiveCheckFail::ProcessPendingHTLCsCheck {
587                 let mut route = get_route(&nodes[0], &route_params).unwrap();
588                 // Set the final CLTV expiry too low to trigger the failure in process_pending_htlc_forwards.
589                 route.paths[0].hops.last_mut().map(|h| h.cltv_expiry_delta += excess_final_cltv_delta_opt.unwrap() as u32);
590                 route.paths[0].blinded_tail.as_mut().map(|bt| bt.excess_final_cltv_expiry_delta = excess_final_cltv_delta_opt.unwrap() as u32);
591                 route
592         } else if check == ReceiveCheckFail::PaymentConstraints {
593                 // Create a blinded path where the receiver's encrypted payload has an htlc_minimum_msat that is
594                 // violated by `amt_msat`, and stick it in the route_params without changing the corresponding
595                 // BlindedPayInfo (to ensure pathfinding still succeeds).
596                 let high_htlc_min_bp = {
597                         let mut high_htlc_minimum_upd = chan_upd_1_2.clone();
598                         high_htlc_minimum_upd.htlc_minimum_msat = amt_msat + 1000;
599                         let high_htlc_min_params = get_blinded_route_parameters(amt_msat, payment_secret,
600                                 nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&high_htlc_minimum_upd],
601                                 &chanmon_cfgs[2].keys_manager);
602                         if let Payee::Blinded { route_hints, .. } = high_htlc_min_params.payment_params.payee {
603                                 route_hints[0].1.clone()
604                         } else { panic!() }
605                 };
606                 if let Payee::Blinded { ref mut route_hints, .. } = route_params.payment_params.payee {
607                         route_hints[0].1 = high_htlc_min_bp;
608                 } else { panic!() }
609                 find_route(&nodes[0], &route_params).unwrap()
610         } else {
611                 find_route(&nodes[0], &route_params).unwrap()
612         };
613         node_cfgs[0].router.expect_find_route(route_params.clone(), Ok(route.clone()));
614         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
615         check_added_monitors(&nodes[0], 1);
616
617         let mut payment_event_0_1 = {
618                 let mut events = nodes[0].node.get_and_clear_pending_msg_events();
619                 assert_eq!(events.len(), 1);
620                 let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
621                 SendEvent::from_event(ev)
622         };
623         nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event_0_1.msgs[0]);
624         check_added_monitors!(nodes[1], 0);
625         do_commitment_signed_dance(&nodes[1], &nodes[0], &payment_event_0_1.commitment_msg, false, false);
626         expect_pending_htlcs_forwardable!(nodes[1]);
627         check_added_monitors!(&nodes[1], 1);
628
629         let mut payment_event_1_2 = {
630                 let mut events = nodes[1].node.get_and_clear_pending_msg_events();
631                 assert_eq!(events.len(), 1);
632                 let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
633                 SendEvent::from_event(ev)
634         };
635
636         match check {
637                 ReceiveCheckFail::RecipientFail => {
638                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
639                         check_added_monitors!(nodes[2], 0);
640                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
641                         expect_pending_htlcs_forwardable!(nodes[2]);
642                         check_payment_claimable(
643                                 &nodes[2].node.get_and_clear_pending_events()[0], payment_hash, payment_secret, amt_msat,
644                                 None, nodes[2].node.get_our_node_id()
645                         );
646                         nodes[2].node.fail_htlc_backwards(&payment_hash);
647                         expect_pending_htlcs_forwardable_conditions(
648                                 nodes[2].node.get_and_clear_pending_events(), &[HTLCDestination::FailedPayment { payment_hash }]
649                         );
650                         nodes[2].node.process_pending_htlc_forwards();
651                         check_added_monitors!(nodes[2], 1);
652                 },
653                 ReceiveCheckFail::OnionDecodeFail => {
654                         let session_priv = SecretKey::from_slice(&session_priv).unwrap();
655                         let mut onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
656                         let cur_height = nodes[0].best_block_info().1;
657                         let (mut onion_payloads, ..) = onion_utils::build_onion_payloads(
658                                 &route.paths[0], amt_msat, RecipientOnionFields::spontaneous_empty(), cur_height, &None).unwrap();
659
660                         let update_add = &mut payment_event_1_2.msgs[0];
661                         onion_payloads.last_mut().map(|p| {
662                                 if let msgs::OutboundOnionPayload::BlindedReceive { ref mut intro_node_blinding_point, .. } = p {
663                                         // The receiver should error if both the update_add blinding_point and the
664                                         // intro_node_blinding_point are set.
665                                         assert!(intro_node_blinding_point.is_none() && update_add.blinding_point.is_some());
666                                         *intro_node_blinding_point = Some(PublicKey::from_slice(&[2; 33]).unwrap());
667                                 } else { panic!() }
668                         });
669                         update_add.onion_routing_packet = onion_utils::construct_onion_packet(
670                                 vec![onion_payloads.pop().unwrap()], vec![onion_keys.pop().unwrap()], [0; 32],
671                                 &payment_hash
672                         ).unwrap();
673                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), update_add);
674                         check_added_monitors!(nodes[2], 0);
675                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
676                 },
677                 ReceiveCheckFail::ReceiveRequirements => {
678                         let update_add = &mut payment_event_1_2.msgs[0];
679                         update_add.amount_msat -= 1;
680                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), update_add);
681                         check_added_monitors!(nodes[2], 0);
682                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
683                 },
684                 ReceiveCheckFail::ChannelCheck => {
685                         nodes[2].node.close_channel(&chan_id_1_2, &nodes[1].node.get_our_node_id()).unwrap();
686                         let node_2_shutdown = get_event_msg!(nodes[2], MessageSendEvent::SendShutdown, nodes[1].node.get_our_node_id());
687                         nodes[1].node.handle_shutdown(&nodes[2].node.get_our_node_id(), &node_2_shutdown);
688                         let node_1_shutdown = get_event_msg!(nodes[1], MessageSendEvent::SendShutdown, nodes[2].node.get_our_node_id());
689
690                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
691                         nodes[2].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &payment_event_1_2.commitment_msg);
692                         check_added_monitors!(nodes[2], 1);
693
694                         nodes[2].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &node_1_shutdown);
695                         commitment_signed_dance!(nodes[2], nodes[1], (), false, true, false, false);
696                 },
697                 ReceiveCheckFail::ProcessPendingHTLCsCheck => {
698                         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);
699                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
700                         check_added_monitors!(nodes[2], 0);
701                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
702                         expect_pending_htlcs_forwardable!(nodes[2]);
703                         expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[2],
704                                 vec![HTLCDestination::FailedPayment { payment_hash }]);
705                         check_added_monitors!(nodes[2], 1);
706                 },
707                 ReceiveCheckFail::PaymentConstraints => {
708                         nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event_1_2.msgs[0]);
709                         check_added_monitors!(nodes[2], 0);
710                         do_commitment_signed_dance(&nodes[2], &nodes[1], &payment_event_1_2.commitment_msg, true, true);
711                 }
712         }
713
714         let updates_2_1 = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
715         assert_eq!(updates_2_1.update_fail_malformed_htlcs.len(), 1);
716         let update_malformed = &updates_2_1.update_fail_malformed_htlcs[0];
717         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
718         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
719         nodes[1].node.handle_update_fail_malformed_htlc(&nodes[2].node.get_our_node_id(), update_malformed);
720         do_commitment_signed_dance(&nodes[1], &nodes[2], &updates_2_1.commitment_signed, true, false);
721
722         let updates_1_0 = if check == ReceiveCheckFail::ChannelCheck {
723                 let events = nodes[1].node.get_and_clear_pending_msg_events();
724                 assert_eq!(events.len(), 2);
725                 events.into_iter().find_map(|ev| {
726                         match ev {
727                                 MessageSendEvent:: UpdateHTLCs { node_id, updates } => {
728                                         assert_eq!(node_id, nodes[0].node.get_our_node_id());
729                                         return Some(updates)
730                                 },
731                                 MessageSendEvent::SendClosingSigned { .. } => None,
732                                 _ => panic!()
733                         }
734                 }).unwrap()
735         } else { get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id()) };
736         assert_eq!(updates_1_0.update_fail_htlcs.len(), 1);
737         nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &updates_1_0.update_fail_htlcs[0]);
738         do_commitment_signed_dance(&nodes[0], &nodes[1], &updates_1_0.commitment_signed, false, false);
739         expect_payment_failed_conditions(&nodes[0], payment_hash, false,
740                 PaymentFailedConditions::new().expected_htlc_error_data(INVALID_ONION_BLINDING, &[0; 32]));
741 }
742
743 #[test]
744 fn blinded_path_retries() {
745         let chanmon_cfgs = create_chanmon_cfgs(4);
746         // Make one blinded path's fees slightly higher so they are tried in a deterministic order.
747         let mut higher_fee_chan_cfg = test_default_channel_config();
748         higher_fee_chan_cfg.channel_config.forwarding_fee_base_msat += 1;
749         let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
750         let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, Some(higher_fee_chan_cfg), None]);
751         let mut nodes = create_network(4, &node_cfgs, &node_chanmgrs);
752
753         // Create this network topology so nodes[0] has a blinded route hint to retry over.
754         //      n1
755         //    /    \
756         // n0       n3
757         //    \    /
758         //      n2
759         create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
760         create_announced_chan_between_nodes_with_value(&nodes, 0, 2, 1_000_000, 0);
761         let chan_1_3 = create_announced_chan_between_nodes_with_value(&nodes, 1, 3, 1_000_000, 0);
762         let chan_2_3 = create_announced_chan_between_nodes_with_value(&nodes, 2, 3, 1_000_000, 0);
763
764         let amt_msat = 5000;
765         let (_, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[3], Some(amt_msat), None);
766         let route_params = {
767                 let pay_params = PaymentParameters::blinded(
768                         vec![
769                                 blinded_payment_path(payment_secret,
770                                         vec![nodes[1].node.get_our_node_id(), nodes[3].node.get_our_node_id()], &[&chan_1_3.0.contents],
771                                         &chanmon_cfgs[3].keys_manager
772                                 ),
773                                 blinded_payment_path(payment_secret,
774                                         vec![nodes[2].node.get_our_node_id(), nodes[3].node.get_our_node_id()], &[&chan_2_3.0.contents],
775                                         &chanmon_cfgs[3].keys_manager
776                                 ),
777                         ]
778                 )
779                         .with_bolt12_features(channelmanager::provided_bolt12_invoice_features(&UserConfig::default()))
780                         .unwrap();
781                 RouteParameters::from_payment_params_and_value(pay_params, amt_msat)
782         };
783
784         nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params.clone(), Retry::Attempts(2)).unwrap();
785         check_added_monitors(&nodes[0], 1);
786         pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[3]]], amt_msat, payment_hash, payment_secret);
787
788         macro_rules! fail_payment_back {
789                 ($intro_node: expr) => {
790                         nodes[3].node.fail_htlc_backwards(&payment_hash);
791                         expect_pending_htlcs_forwardable_conditions(
792                                 nodes[3].node.get_and_clear_pending_events(), &[HTLCDestination::FailedPayment { payment_hash }]
793                         );
794                         nodes[3].node.process_pending_htlc_forwards();
795                         check_added_monitors!(nodes[3], 1);
796
797                         let updates = get_htlc_update_msgs!(nodes[3], $intro_node.node.get_our_node_id());
798                         assert_eq!(updates.update_fail_malformed_htlcs.len(), 1);
799                         let update_malformed = &updates.update_fail_malformed_htlcs[0];
800                         assert_eq!(update_malformed.sha256_of_onion, [0; 32]);
801                         assert_eq!(update_malformed.failure_code, INVALID_ONION_BLINDING);
802                         $intro_node.node.handle_update_fail_malformed_htlc(&nodes[3].node.get_our_node_id(), update_malformed);
803                         do_commitment_signed_dance(&$intro_node, &nodes[3], &updates.commitment_signed, true, false);
804
805                         let updates =  get_htlc_update_msgs!($intro_node, nodes[0].node.get_our_node_id());
806                         assert_eq!(updates.update_fail_htlcs.len(), 1);
807                         nodes[0].node.handle_update_fail_htlc(&$intro_node.node.get_our_node_id(), &updates.update_fail_htlcs[0]);
808                         do_commitment_signed_dance(&nodes[0], &$intro_node, &updates.commitment_signed, false, false);
809
810                         let mut events = nodes[0].node.get_and_clear_pending_events();
811                         assert_eq!(events.len(), 2);
812                         match events[0] {
813                                 Event::PaymentPathFailed { payment_hash: ev_payment_hash, payment_failed_permanently, ..  } => {
814                                         assert_eq!(payment_hash, ev_payment_hash);
815                                         assert_eq!(payment_failed_permanently, false);
816                                 },
817                                 _ => panic!("Unexpected event"),
818                         }
819                         match events[1] {
820                                 Event::PendingHTLCsForwardable { .. } => {},
821                                 _ => panic!("Unexpected event"),
822                         }
823                         nodes[0].node.process_pending_htlc_forwards();
824                 }
825         }
826
827         fail_payment_back!(nodes[1]);
828
829         // Pass the retry along.
830         check_added_monitors!(nodes[0], 1);
831         let mut msg_events = nodes[0].node.get_and_clear_pending_msg_events();
832         assert_eq!(msg_events.len(), 1);
833         pass_along_path(&nodes[0], &[&nodes[2], &nodes[3]], amt_msat, payment_hash, Some(payment_secret), msg_events.pop().unwrap(), true, None);
834
835         fail_payment_back!(nodes[2]);
836         let evs = nodes[0].node.get_and_clear_pending_events();
837         assert_eq!(evs.len(), 1);
838         match evs[0] {
839                 Event::PaymentFailed { payment_hash: ev_payment_hash, reason, .. } => {
840                         assert_eq!(ev_payment_hash, payment_hash);
841                         // We have 1 retry attempt remaining, but we're out of blinded paths to try.
842                         assert_eq!(reason, Some(PaymentFailureReason::RouteNotFound));
843                 },
844                 _ => panic!()
845         }
846 }