_ 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::Bolt11Invoice;
  13
  14 use bitcoin_hashes::Hash;
  15
  16 use lightning::chain;
  17 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  18 use lightning::sign::{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 [`Bolt11Invoice`], retrying if needed based on [`Retry`].
  29 ///
  30 /// [`Bolt11Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  31 /// as the payment is still pending. If the payment succeeds, you must ensure that a second payment
  32 /// 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: &Bolt11Invoice, 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 [`Bolt11Invoice`] with a custom idempotency key, retrying if needed based on
  55 /// [`Retry`].
  56 ///
  57 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
  58 /// payment completes or fails, no idempotency guarantees are made.
  59 ///
  60 /// You should ensure that the [`Bolt11Invoice::payment_hash`] is unique and the same
  61 /// [`PaymentHash`] has never been paid before.
  62 ///
  63 /// See [`pay_invoice`] for a variant which uses the [`PaymentHash`] for the idempotency token.
  64 pub fn pay_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
  65         invoice: &Bolt11Invoice, payment_id: PaymentId, retry_strategy: Retry,
  66         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
  67 ) -> Result<(), PaymentError>
  68 where
  69                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
  70                 T::Target: BroadcasterInterface,
  71                 ES::Target: EntropySource,
  72                 NS::Target: NodeSigner,
  73                 SP::Target: SignerProvider,
  74                 F::Target: FeeEstimator,
  75                 R::Target: Router,
  76                 L::Target: Logger,
  77 {
  78         let amt_msat = invoice.amount_milli_satoshis().ok_or(PaymentError::Invoice("amount missing"))?;
  79         pay_invoice_using_amount(invoice, amt_msat, payment_id, retry_strategy, channelmanager)
  80 }
  81
  82 /// Pays the given zero-value [`Bolt11Invoice`] using the given amount, retrying if needed based on
  83 /// [`Retry`].
  84 ///
  85 /// [`Bolt11Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
  86 /// as the payment is still pending. If the payment succeeds, you must ensure that a second payment
  87 /// with the same [`PaymentHash`] is never sent.
  88 ///
  89 /// If you wish to use a different payment idempotency token, see
  90 /// [`pay_zero_value_invoice_with_id`].
  91 pub fn pay_zero_value_invoice<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
  92         invoice: &Bolt11Invoice, amount_msats: u64, retry_strategy: Retry,
  93         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
  94 ) -> Result<PaymentId, PaymentError>
  95 where
  96                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
  97                 T::Target: BroadcasterInterface,
  98                 ES::Target: EntropySource,
  99                 NS::Target: NodeSigner,
 100                 SP::Target: SignerProvider,
 101                 F::Target: FeeEstimator,
 102                 R::Target: Router,
 103                 L::Target: Logger,
 104 {
 105         let payment_id = PaymentId(invoice.payment_hash().into_inner());
 106         pay_zero_value_invoice_with_id(invoice, amount_msats, payment_id, retry_strategy,
 107                 channelmanager)
 108                 .map(|()| payment_id)
 109 }
 110
 111 /// Pays the given zero-value [`Bolt11Invoice`] using the given amount and custom idempotency key,
 112 /// retrying if needed based on [`Retry`].
 113 ///
 114 /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
 115 /// payment completes or fails, no idempotency guarantees are made.
 116 ///
 117 /// You should ensure that the [`Bolt11Invoice::payment_hash`] is unique and the same
 118 /// [`PaymentHash`] has never been paid before.
 119 ///
 120 /// See [`pay_zero_value_invoice`] for a variant which uses the [`PaymentHash`] for the
 121 /// idempotency token.
 122 pub fn pay_zero_value_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
 123         invoice: &Bolt11Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
 124         channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
 125 ) -> Result<(), PaymentError>
 126 where
 127                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 128                 T::Target: BroadcasterInterface,
 129                 ES::Target: EntropySource,
 130                 NS::Target: NodeSigner,
 131                 SP::Target: SignerProvider,
 132                 F::Target: FeeEstimator,
 133                 R::Target: Router,
 134                 L::Target: Logger,
 135 {
 136         if invoice.amount_milli_satoshis().is_some() {
 137                 Err(PaymentError::Invoice("amount unexpected"))
 138         } else {
 139                 pay_invoice_using_amount(invoice, amount_msats, payment_id, retry_strategy,
 140                         channelmanager)
 141         }
 142 }
 143
 144 fn pay_invoice_using_amount<P: Deref>(
 145         invoice: &Bolt11Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
 146         payer: P
 147 ) -> Result<(), PaymentError> where P::Target: Payer {
 148         let payment_hash = PaymentHash((*invoice.payment_hash()).into_inner());
 149         let mut recipient_onion = RecipientOnionFields::secret_only(*invoice.payment_secret());
 150         recipient_onion.payment_metadata = invoice.payment_metadata().map(|v| v.clone());
 151         let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
 152                 invoice.min_final_cltv_expiry_delta() as u32)
 153                 .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 154                 .with_route_hints(invoice.route_hints()).unwrap();
 155         if let Some(features) = invoice.features() {
 156                 payment_params = payment_params.with_bolt11_features(features.clone()).unwrap();
 157         }
 158         let route_params = RouteParameters {
 159                 payment_params,
 160                 final_value_msat: amount_msats,
 161         };
 162
 163         payer.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 164 }
 165
 166 fn expiry_time_from_unix_epoch(invoice: &Bolt11Invoice) -> Duration {
 167         invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 168 }
 169
 170 /// An error that may occur when making a payment.
 171 #[derive(Clone, Debug, PartialEq, Eq)]
 172 pub enum PaymentError {
 173         /// An error resulting from the provided [`Bolt11Invoice`] or payment hash.
 174         Invoice(&'static str),
 175         /// An error occurring when sending a payment.
 176         Sending(RetryableSendFailure),
 177 }
 178
 179 /// A trait defining behavior of a [`Bolt11Invoice`] payer.
 180 ///
 181 /// Useful for unit testing internal methods.
 182 trait Payer {
 183         /// Sends a payment over the Lightning Network using the given [`Route`].
 184         ///
 185         /// [`Route`]: lightning::routing::router::Route
 186         fn send_payment(
 187                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 188                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 189         ) -> Result<(), PaymentError>;
 190 }
 191
 192 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>
 193 where
 194                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 195                 T::Target: BroadcasterInterface,
 196                 ES::Target: EntropySource,
 197                 NS::Target: NodeSigner,
 198                 SP::Target: SignerProvider,
 199                 F::Target: FeeEstimator,
 200                 R::Target: Router,
 201                 L::Target: Logger,
 202 {
 203         fn send_payment(
 204                 &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
 205                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 206         ) -> Result<(), PaymentError> {
 207                 self.send_payment(payment_hash, recipient_onion, payment_id, route_params, retry_strategy)
 208                         .map_err(PaymentError::Sending)
 209         }
 210 }
 211
 212 #[cfg(test)]
 213 mod tests {
 214         use super::*;
 215         use crate::{InvoiceBuilder, Currency};
 216         use bitcoin_hashes::sha256::Hash as Sha256;
 217         use lightning::events::Event;
 218         use lightning::ln::msgs::ChannelMessageHandler;
 219         use lightning::ln::{PaymentPreimage, PaymentSecret};
 220         use lightning::ln::functional_test_utils::*;
 221         use secp256k1::{SecretKey, Secp256k1};
 222         use std::collections::VecDeque;
 223         use std::time::{SystemTime, Duration};
 224
 225         struct TestPayer {
 226                 expectations: core::cell::RefCell<VecDeque<Amount>>,
 227         }
 228
 229         impl TestPayer {
 230                 fn new() -> Self {
 231                         Self {
 232                                 expectations: core::cell::RefCell::new(VecDeque::new()),
 233                         }
 234                 }
 235
 236                 fn expect_send(self, value_msat: Amount) -> Self {
 237                         self.expectations.borrow_mut().push_back(value_msat);
 238                         self
 239                 }
 240
 241                 fn check_value_msats(&self, actual_value_msats: Amount) {
 242                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
 243                         if let Some(expected_value_msats) = expected_value_msats {
 244                                 assert_eq!(actual_value_msats, expected_value_msats);
 245                         } else {
 246                                 panic!("Unexpected amount: {:?}", actual_value_msats);
 247                         }
 248                 }
 249         }
 250
 251         #[derive(Clone, Debug, PartialEq, Eq)]
 252         struct Amount(u64); // msat
 253
 254         impl Payer for TestPayer {
 255                 fn send_payment(
 256                         &self, _payment_hash: PaymentHash, _recipient_onion: RecipientOnionFields,
 257                         _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
 258                 ) -> Result<(), PaymentError> {
 259                         self.check_value_msats(Amount(route_params.final_value_msat));
 260                         Ok(())
 261                 }
 262         }
 263
 264         impl Drop for TestPayer {
 265                 fn drop(&mut self) {
 266                         if std::thread::panicking() {
 267                                 return;
 268                         }
 269
 270                         if !self.expectations.borrow().is_empty() {
 271                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
 272                         }
 273                 }
 274         }
 275
 276         fn duration_since_epoch() -> Duration {
 277                 #[cfg(feature = "std")]
 278                 let duration_since_epoch =
 279                         SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 280                 #[cfg(not(feature = "std"))]
 281                 let duration_since_epoch = Duration::from_secs(1234567);
 282                 duration_since_epoch
 283         }
 284
 285         fn invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 286                 let payment_hash = Sha256::hash(&payment_preimage.0);
 287                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 288
 289                 InvoiceBuilder::new(Currency::Bitcoin)
 290                         .description("test".into())
 291                         .payment_hash(payment_hash)
 292                         .payment_secret(PaymentSecret([0; 32]))
 293                         .duration_since_epoch(duration_since_epoch())
 294                         .min_final_cltv_expiry_delta(144)
 295                         .amount_milli_satoshis(128)
 296                         .build_signed(|hash| {
 297                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 298                         })
 299                         .unwrap()
 300         }
 301
 302         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Bolt11Invoice {
 303                 let payment_hash = Sha256::hash(&payment_preimage.0);
 304                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 305
 306                 InvoiceBuilder::new(Currency::Bitcoin)
 307                         .description("test".into())
 308                         .payment_hash(payment_hash)
 309                         .payment_secret(PaymentSecret([0; 32]))
 310                         .duration_since_epoch(duration_since_epoch())
 311                         .min_final_cltv_expiry_delta(144)
 312                         .build_signed(|hash| {
 313                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 314                         })
 315                 .unwrap()
 316         }
 317
 318         #[test]
 319         fn pays_invoice() {
 320                 let payment_id = PaymentId([42; 32]);
 321                 let payment_preimage = PaymentPreimage([1; 32]);
 322                 let invoice = invoice(payment_preimage);
 323                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 324
 325                 let payer = TestPayer::new().expect_send(Amount(final_value_msat));
 326                 pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 327         }
 328
 329         #[test]
 330         fn pays_zero_value_invoice() {
 331                 let payment_id = PaymentId([42; 32]);
 332                 let payment_preimage = PaymentPreimage([1; 32]);
 333                 let invoice = zero_value_invoice(payment_preimage);
 334                 let amt_msat = 10_000;
 335
 336                 let payer = TestPayer::new().expect_send(Amount(amt_msat));
 337                 pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 338         }
 339
 340         #[test]
 341         fn fails_paying_zero_value_invoice_with_amount() {
 342                 let chanmon_cfgs = create_chanmon_cfgs(1);
 343                 let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 344                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 345                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 346
 347                 let payment_preimage = PaymentPreimage([1; 32]);
 348                 let invoice = invoice(payment_preimage);
 349                 let amt_msat = 10_000;
 350
 351                 match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), nodes[0].node) {
 352                         Err(PaymentError::Invoice("amount unexpected")) => {},
 353                         _ => panic!()
 354                 }
 355         }
 356
 357         #[test]
 358         #[cfg(feature = "std")]
 359         fn payment_metadata_end_to_end() {
 360                 // Test that a payment metadata read from an invoice passed to `pay_invoice` makes it all
 361                 // the way out through the `PaymentClaimable` event.
 362                 let chanmon_cfgs = create_chanmon_cfgs(2);
 363                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 364                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 365                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 366                 create_announced_chan_between_nodes(&nodes, 0, 1);
 367
 368                 let payment_metadata = vec![42, 43, 44, 45, 46, 47, 48, 49, 42];
 369
 370                 let (payment_hash, payment_secret) =
 371                         nodes[1].node.create_inbound_payment(None, 7200, None).unwrap();
 372
 373                 let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 374                         .description("test".into())
 375                         .payment_hash(Sha256::from_slice(&payment_hash.0).unwrap())
 376                         .payment_secret(payment_secret)
 377                         .current_timestamp()
 378                         .min_final_cltv_expiry_delta(144)
 379                         .amount_milli_satoshis(50_000)
 380                         .payment_metadata(payment_metadata.clone())
 381                         .build_signed(|hash| {
 382                                 Secp256k1::new().sign_ecdsa_recoverable(hash,
 383                                         &nodes[1].keys_manager.backing.get_node_secret_key())
 384                         })
 385                         .unwrap();
 386
 387                 pay_invoice(&invoice, Retry::Attempts(0), nodes[0].node).unwrap();
 388                 check_added_monitors(&nodes[0], 1);
 389                 let send_event = SendEvent::from_node(&nodes[0]);
 390                 nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_event.msgs[0]);
 391                 commitment_signed_dance!(nodes[1], nodes[0], &send_event.commitment_msg, false);
 392
 393                 expect_pending_htlcs_forwardable!(nodes[1]);
 394
 395                 let mut events = nodes[1].node.get_and_clear_pending_events();
 396                 assert_eq!(events.len(), 1);
 397                 match events.pop().unwrap() {
 398                         Event::PaymentClaimable { onion_fields, .. } => {
 399                                 assert_eq!(Some(payment_metadata), onion_fields.unwrap().payment_metadata);
 400                         },
 401                         _ => panic!("Unexpected event")
 402                 }
 403         }
 404 }