_ Git - rust-lightning/blob - lightning-invoice/src/payment.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 //! Convenient utilities for paying Lightning invoices and sending spontaneous payments.
  11
  12 use crate::Invoice;
  13
  14 use bitcoin_hashes::Hash;
  15
  16 use lightning::chain;
  17 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  18 use lightning::chain::keysinterface::{NodeSigner, SignerProvider, EntropySource};
  19 use lightning::ln::PaymentHash;
  20 use lightning::ln::channelmanager::{ChannelManager, PaymentId, Retry, RetryableSendFailure, RecipientOnionFields};
  21 use lightning::routing::router::{PaymentParameters, RouteParameters, Router};
  22 use lightning::util::logger::Logger;
  23
  24 use core::fmt::Debug;
  25 use core::ops::Deref;
  26 use core::time::Duration;
  27
  28 /// Pays the given [`Invoice`], retrying if needed based on [`Retry`].
  29 ///
  30 /// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  31 /// as the payment is still pending. Once the payment completes or fails, you must ensure that
  32 /// a second payment with the same [`PaymentHash`] is never sent.
  33 ///
  34 /// If you wish to use a different payment idempotency token, see [`pay_invoice_with_id`].
  35 pub fn pay_invoice<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
  36         invoice: &Invoice, retry_strategy: Retry,
  37         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
  38 ) -> Result<PaymentId, PaymentError>
  39 where
  40                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
  41                 T::Target: BroadcasterInterface,
  42                 ES::Target: EntropySource,
  43                 NS::Target: NodeSigner,
  44                 SP::Target: SignerProvider,
  45                 F::Target: FeeEstimator,
  46                 R::Target: Router,
  47                 L::Target: Logger,
  48 {
  49         let payment_id = PaymentId(invoice.payment_hash().into_inner());
  50         pay_invoice_with_id(invoice, payment_id, retry_strategy, channelmanager)
  51                 .map(|()| payment_id)
  52 }
  53
  54 /// Pays the given [`Invoice`] with a custom idempotency key, retrying if needed based on [`Retry`].
  55 ///
  56 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
  57 /// payment completes or fails, no idempotency guarantees are made.
  58 ///
  59 /// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
  60 /// has never been paid before.
  61 ///
  62 /// See [`pay_invoice`] for a variant which uses the [`PaymentHash`] for the idempotency token.
  63 pub fn pay_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
  64         invoice: &Invoice, payment_id: PaymentId, retry_strategy: Retry,
  65         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
  66 ) -> Result<(), PaymentError>
  67 where
  68                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
  69                 T::Target: BroadcasterInterface,
  70                 ES::Target: EntropySource,
  71                 NS::Target: NodeSigner,
  72                 SP::Target: SignerProvider,
  73                 F::Target: FeeEstimator,
  74                 R::Target: Router,
  75                 L::Target: Logger,
  76 {
  77         let amt_msat = invoice.amount_milli_satoshis().ok_or(PaymentError::Invoice("amount missing"))?;
  78         pay_invoice_using_amount(invoice, amt_msat, payment_id, retry_strategy, channelmanager)
  79 }
  80
  81 /// Pays the given zero-value [`Invoice`] using the given amount, retrying if needed based on
  82 /// [`Retry`].
  83 ///
  84 /// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  85 /// as the payment is still pending. Once the payment completes or fails, you must ensure that
  86 /// a second payment with the same [`PaymentHash`] is never sent.
  87 ///
  88 /// If you wish to use a different payment idempotency token, see
  89 /// [`pay_zero_value_invoice_with_id`].
  90 pub fn pay_zero_value_invoice<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
  91         invoice: &Invoice, amount_msats: u64, retry_strategy: Retry,
  92         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
  93 ) -> Result<PaymentId, PaymentError>
  94 where
  95                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
  96                 T::Target: BroadcasterInterface,
  97                 ES::Target: EntropySource,
  98                 NS::Target: NodeSigner,
  99                 SP::Target: SignerProvider,
 100                 F::Target: FeeEstimator,
 101                 R::Target: Router,
 102                 L::Target: Logger,
 103 {
 104         let payment_id = PaymentId(invoice.payment_hash().into_inner());
 105         pay_zero_value_invoice_with_id(invoice, amount_msats, payment_id, retry_strategy,
 106                 channelmanager)
 107                 .map(|()| payment_id)
 108 }
 109
 110 /// Pays the given zero-value [`Invoice`] using the given amount and custom idempotency key,
 111 /// , retrying if needed based on [`Retry`].
 112 ///
 113 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
 114 /// payment completes or fails, no idempotency guarantees are made.
 115 ///
 116 /// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
 117 /// has never been paid before.
 118 ///
 119 /// See [`pay_zero_value_invoice`] for a variant which uses the [`PaymentHash`] for the
 120 /// idempotency token.
 121 pub fn pay_zero_value_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
 122         invoice: &Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
 123         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
 124 ) -> Result<(), PaymentError>
 125 where
 126                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 127                 T::Target: BroadcasterInterface,
 128                 ES::Target: EntropySource,
 129                 NS::Target: NodeSigner,
 130                 SP::Target: SignerProvider,
 131                 F::Target: FeeEstimator,
 132                 R::Target: Router,
 133                 L::Target: Logger,
 134 {
 135         if invoice.amount_milli_satoshis().is_some() {
 136                 Err(PaymentError::Invoice("amount unexpected"))
 137         } else {
 138                 pay_invoice_using_amount(invoice, amount_msats, payment_id, retry_strategy,
 139                         channelmanager)
 140         }
 141 }
 142
 143 fn pay_invoice_using_amount<P: Deref>(
 144         invoice: &Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
 145         payer: P
 146 ) -> Result<(), PaymentError> where P::Target: Payer {
 147         let payment_hash = PaymentHash((*invoice.payment_hash()).into_inner());
 148         let recipient_onion = RecipientOnionFields {
 149                 payment_secret: Some(*invoice.payment_secret()),
 150                 payment_metadata: invoice.payment_metadata().map(|v| v.clone()),
 151         };
 152         let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
 153                 invoice.min_final_cltv_expiry_delta() as u32)
 154                 .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 155                 .with_route_hints(invoice.route_hints());
 156         if let Some(features) = invoice.features() {
 157                 payment_params = payment_params.with_features(features.clone());
 158         }
 159         let route_params = RouteParameters {
 160                 payment_params,
 161                 final_value_msat: amount_msats,
 162         };
 163
 164         payer.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 165 }
 166
 167 fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
 168         invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 169 }
 170
 171 /// An error that may occur when making a payment.
 172 #[derive(Clone, Debug)]
 173 pub enum PaymentError {
 174         /// An error resulting from the provided [`Invoice`] or payment hash.
 175         Invoice(&'static str),
 176         /// An error occurring when sending a payment.
 177         Sending(RetryableSendFailure),
 178 }
 179
 180 /// A trait defining behavior of an [`Invoice`] payer.
 181 ///
 182 /// Useful for unit testing internal methods.
 183 trait Payer {
 184         /// Sends a payment over the Lightning Network using the given [`Route`].
 185         ///
 186         /// [`Route`]: lightning::routing::router::Route
 187         fn send_payment(
 188                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 189                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 190         ) -> Result<(), PaymentError>;
 191 }
 192
 193 impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> Payer for ChannelManager<M, T, ES, NS, SP, F, R, L>
 194 where
 195                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 196                 T::Target: BroadcasterInterface,
 197                 ES::Target: EntropySource,
 198                 NS::Target: NodeSigner,
 199                 SP::Target: SignerProvider,
 200                 F::Target: FeeEstimator,
 201                 R::Target: Router,
 202                 L::Target: Logger,
 203 {
 204         fn send_payment(
 205                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 206                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 207         ) -> Result<(), PaymentError> {
 208                 self.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 209                         .map_err(PaymentError::Sending)
 210         }
 211 }
 212
 213 #[cfg(test)]
 214 mod tests {
 215         use super::*;
 216         use crate::{InvoiceBuilder, Currency};
 217         use bitcoin_hashes::sha256::Hash as Sha256;
 218         use lightning::events::Event;
 219         use lightning::ln::msgs::ChannelMessageHandler;
 220         use lightning::ln::{PaymentPreimage, PaymentSecret};
 221         use lightning::ln::functional_test_utils::*;
 222         use secp256k1::{SecretKey, Secp256k1};
 223         use std::collections::VecDeque;
 224         use std::time::{SystemTime, Duration};
 225
 226         struct TestPayer {
 227                 expectations: core::cell::RefCell<VecDeque<Amount>>,
 228         }
 229
 230         impl TestPayer {
 231                 fn new() -> Self {
 232                         Self {
 233                                 expectations: core::cell::RefCell::new(VecDeque::new()),
 234                         }
 235                 }
 236
 237                 fn expect_send(self, value_msat: Amount) -> Self {
 238                         self.expectations.borrow_mut().push_back(value_msat);
 239                         self
 240                 }
 241
 242                 fn check_value_msats(&self, actual_value_msats: Amount) {
 243                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
 244                         if let Some(expected_value_msats) = expected_value_msats {
 245                                 assert_eq!(actual_value_msats, expected_value_msats);
 246                         } else {
 247                                 panic!("Unexpected amount: {:?}", actual_value_msats);
 248                         }
 249                 }
 250         }
 251
 252         #[derive(Clone, Debug, PartialEq, Eq)]
 253         struct Amount(u64); // msat
 254
 255         impl Payer for TestPayer {
 256                 fn send_payment(
 257                         &self, _payment_hash: PaymentHash, _recipient_onion: RecipientOnionFields,
 258                         _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
 259                 ) -> Result<(), PaymentError> {
 260                         self.check_value_msats(Amount(route_params.final_value_msat));
 261                         Ok(())
 262                 }
 263         }
 264
 265         impl Drop for TestPayer {
 266                 fn drop(&mut self) {
 267                         if std::thread::panicking() {
 268                                 return;
 269                         }
 270
 271                         if !self.expectations.borrow().is_empty() {
 272                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
 273                         }
 274                 }
 275         }
 276
 277         fn duration_since_epoch() -> Duration {
 278                 #[cfg(feature = "std")]
 279                 let duration_since_epoch =
 280                         SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 281                 #[cfg(not(feature = "std"))]
 282                 let duration_since_epoch = Duration::from_secs(1234567);
 283                 duration_since_epoch
 284         }
 285
 286         fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
 287                 let payment_hash = Sha256::hash(&payment_preimage.0);
 288                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 289
 290                 InvoiceBuilder::new(Currency::Bitcoin)
 291                         .description("test".into())
 292                         .payment_hash(payment_hash)
 293                         .payment_secret(PaymentSecret([0; 32]))
 294                         .duration_since_epoch(duration_since_epoch())
 295                         .min_final_cltv_expiry_delta(144)
 296                         .amount_milli_satoshis(128)
 297                         .build_signed(|hash| {
 298                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 299                         })
 300                         .unwrap()
 301         }
 302
 303         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 304                 let payment_hash = Sha256::hash(&payment_preimage.0);
 305                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 306
 307                 InvoiceBuilder::new(Currency::Bitcoin)
 308                         .description("test".into())
 309                         .payment_hash(payment_hash)
 310                         .payment_secret(PaymentSecret([0; 32]))
 311                         .duration_since_epoch(duration_since_epoch())
 312                         .min_final_cltv_expiry_delta(144)
 313                         .build_signed(|hash| {
 314                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 315                         })
 316                 .unwrap()
 317         }
 318
 319         #[test]
 320         fn pays_invoice() {
 321                 let payment_id = PaymentId([42; 32]);
 322                 let payment_preimage = PaymentPreimage([1; 32]);
 323                 let invoice = invoice(payment_preimage);
 324                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 325
 326                 let payer = TestPayer::new().expect_send(Amount(final_value_msat));
 327                 pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 328         }
 329
 330         #[test]
 331         fn pays_zero_value_invoice() {
 332                 let payment_id = PaymentId([42; 32]);
 333                 let payment_preimage = PaymentPreimage([1; 32]);
 334                 let invoice = zero_value_invoice(payment_preimage);
 335                 let amt_msat = 10_000;
 336
 337                 let payer = TestPayer::new().expect_send(Amount(amt_msat));
 338                 pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 339         }
 340
 341         #[test]
 342         fn fails_paying_zero_value_invoice_with_amount() {
 343                 let chanmon_cfgs = create_chanmon_cfgs(1);
 344                 let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 345                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 346                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 347
 348                 let payment_preimage = PaymentPreimage([1; 32]);
 349                 let invoice = invoice(payment_preimage);
 350                 let amt_msat = 10_000;
 351
 352                 match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), nodes[0].node) {
 353                         Err(PaymentError::Invoice("amount unexpected")) => {},
 354                         _ => panic!()
 355                 }
 356         }
 357
 358         #[test]
 359         #[cfg(feature = "std")]
 360         fn payment_metadata_end_to_end() {
 361                 // Test that a payment metadata read from an invoice passed to `pay_invoice` makes it all
 362                 // the way out through the `PaymentClaimable` event.
 363                 let chanmon_cfgs = create_chanmon_cfgs(2);
 364                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 365                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 366                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 367                 create_announced_chan_between_nodes(&nodes, 0, 1);
 368
 369                 let payment_metadata = vec![42, 43, 44, 45, 46, 47, 48, 49, 42];
 370
 371                 let (payment_hash, payment_secret) =
 372                         nodes[1].node.create_inbound_payment(None, 7200, None).unwrap();
 373
 374                 let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 375                         .description("test".into())
 376                         .payment_hash(Sha256::from_slice(&payment_hash.0).unwrap())
 377                         .payment_secret(payment_secret)
 378                         .current_timestamp()
 379                         .min_final_cltv_expiry_delta(144)
 380                         .amount_milli_satoshis(50_000)
 381                         .payment_metadata(payment_metadata.clone())
 382                         .build_signed(|hash| {
 383                                 Secp256k1::new().sign_ecdsa_recoverable(hash,
 384                                         &nodes[1].keys_manager.backing.get_node_secret_key())
 385                         })
 386                         .unwrap();
 387
 388                 pay_invoice(&invoice, Retry::Attempts(0), nodes[0].node).unwrap();
 389                 check_added_monitors(&nodes[0], 1);
 390                 let send_event = SendEvent::from_node(&nodes[0]);
 391                 nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_event.msgs[0]);
 392                 commitment_signed_dance!(nodes[1], nodes[0], &send_event.commitment_msg, false);
 393
 394                 expect_pending_htlcs_forwardable!(nodes[1]);
 395
 396                 let mut events = nodes[1].node.get_and_clear_pending_events();
 397                 assert_eq!(events.len(), 1);
 398                 match events.pop().unwrap() {
 399                         Event::PaymentClaimable { onion_fields, .. } => {
 400                                 assert_eq!(Some(payment_metadata), onion_fields.unwrap().payment_metadata);
 401                         },
 402                         _ => panic!("Unexpected event")
 403                 }
 404         }
 405 }