_ 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, PaymentSecret};
  20 use lightning::ln::channelmanager::{ChannelManager, PaymentId, Retry, RetryableSendFailure};
  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().clone().into_inner());
 148         let payment_secret = Some(invoice.payment_secret().clone());
 149         let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
 150                 invoice.min_final_cltv_expiry_delta() as u32)
 151                 .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs())
 152                 .with_route_hints(invoice.route_hints());
 153         if let Some(features) = invoice.features() {
 154                 payment_params = payment_params.with_features(features.clone());
 155         }
 156         let route_params = RouteParameters {
 157                 payment_params,
 158                 final_value_msat: amount_msats,
 159                 final_cltv_expiry_delta: invoice.min_final_cltv_expiry_delta() as u32,
 160         };
 161
 162         payer.send_payment(payment_hash, &payment_secret, payment_id, route_params, retry_strategy)
 163 }
 164
 165 fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
 166         invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 167 }
 168
 169 /// An error that may occur when making a payment.
 170 #[derive(Clone, Debug)]
 171 pub enum PaymentError {
 172         /// An error resulting from the provided [`Invoice`] or payment hash.
 173         Invoice(&'static str),
 174         /// An error occurring when sending a payment.
 175         Sending(RetryableSendFailure),
 176 }
 177
 178 /// A trait defining behavior of an [`Invoice`] payer.
 179 ///
 180 /// Useful for unit testing internal methods.
 181 trait Payer {
 182         /// Sends a payment over the Lightning Network using the given [`Route`].
 183         ///
 184         /// [`Route`]: lightning::routing::router::Route
 185         fn send_payment(
 186                 &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 187                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 188         ) -> Result<(), PaymentError>;
 189 }
 190
 191 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>
 192 where
 193                 M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
 194                 T::Target: BroadcasterInterface,
 195                 ES::Target: EntropySource,
 196                 NS::Target: NodeSigner,
 197                 SP::Target: SignerProvider,
 198                 F::Target: FeeEstimator,
 199                 R::Target: Router,
 200                 L::Target: Logger,
 201 {
 202         fn send_payment(
 203                 &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
 204                 payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
 205         ) -> Result<(), PaymentError> {
 206                 self.send_payment_with_retry(payment_hash, payment_secret, payment_id, route_params, retry_strategy)
 207                         .map_err(|e| PaymentError::Sending(e))
 208         }
 209 }
 210
 211 #[cfg(test)]
 212 mod tests {
 213         use super::*;
 214         use crate::{InvoiceBuilder, Currency};
 215         use bitcoin_hashes::sha256::Hash as Sha256;
 216         use lightning::ln::PaymentPreimage;
 217         use lightning::ln::functional_test_utils::*;
 218         use secp256k1::{SecretKey, Secp256k1};
 219         use std::collections::VecDeque;
 220         use std::time::{SystemTime, Duration};
 221
 222         struct TestPayer {
 223                 expectations: core::cell::RefCell<VecDeque<Amount>>,
 224         }
 225
 226         impl TestPayer {
 227                 fn new() -> Self {
 228                         Self {
 229                                 expectations: core::cell::RefCell::new(VecDeque::new()),
 230                         }
 231                 }
 232
 233                 fn expect_send(self, value_msat: Amount) -> Self {
 234                         self.expectations.borrow_mut().push_back(value_msat);
 235                         self
 236                 }
 237
 238                 fn check_value_msats(&self, actual_value_msats: Amount) {
 239                         let expected_value_msats = self.expectations.borrow_mut().pop_front();
 240                         if let Some(expected_value_msats) = expected_value_msats {
 241                                 assert_eq!(actual_value_msats, expected_value_msats);
 242                         } else {
 243                                 panic!("Unexpected amount: {:?}", actual_value_msats);
 244                         }
 245                 }
 246         }
 247
 248         #[derive(Clone, Debug, PartialEq, Eq)]
 249         struct Amount(u64); // msat
 250
 251         impl Payer for TestPayer {
 252                 fn send_payment(
 253                         &self, _payment_hash: PaymentHash, _payment_secret: &Option<PaymentSecret>,
 254                         _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
 255                 ) -> Result<(), PaymentError> {
 256                         self.check_value_msats(Amount(route_params.final_value_msat));
 257                         Ok(())
 258                 }
 259         }
 260
 261         impl Drop for TestPayer {
 262                 fn drop(&mut self) {
 263                         if std::thread::panicking() {
 264                                 return;
 265                         }
 266
 267                         if !self.expectations.borrow().is_empty() {
 268                                 panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
 269                         }
 270                 }
 271         }
 272
 273         fn duration_since_epoch() -> Duration {
 274                 #[cfg(feature = "std")]
 275                 let duration_since_epoch =
 276                         SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 277                 #[cfg(not(feature = "std"))]
 278                 let duration_since_epoch = Duration::from_secs(1234567);
 279                 duration_since_epoch
 280         }
 281
 282         fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
 283                 let payment_hash = Sha256::hash(&payment_preimage.0);
 284                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 285
 286                 InvoiceBuilder::new(Currency::Bitcoin)
 287                         .description("test".into())
 288                         .payment_hash(payment_hash)
 289                         .payment_secret(PaymentSecret([0; 32]))
 290                         .duration_since_epoch(duration_since_epoch())
 291                         .min_final_cltv_expiry_delta(144)
 292                         .amount_milli_satoshis(128)
 293                         .build_signed(|hash| {
 294                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 295                         })
 296                         .unwrap()
 297         }
 298
 299         fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 300                 let payment_hash = Sha256::hash(&payment_preimage.0);
 301                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 302
 303                 InvoiceBuilder::new(Currency::Bitcoin)
 304                         .description("test".into())
 305                         .payment_hash(payment_hash)
 306                         .payment_secret(PaymentSecret([0; 32]))
 307                         .duration_since_epoch(duration_since_epoch())
 308                         .min_final_cltv_expiry_delta(144)
 309                         .build_signed(|hash| {
 310                                 Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 311                         })
 312                 .unwrap()
 313         }
 314
 315         #[test]
 316         fn pays_invoice() {
 317                 let payment_id = PaymentId([42; 32]);
 318                 let payment_preimage = PaymentPreimage([1; 32]);
 319                 let invoice = invoice(payment_preimage);
 320                 let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 321
 322                 let payer = TestPayer::new().expect_send(Amount(final_value_msat));
 323                 pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 324         }
 325
 326         #[test]
 327         fn pays_zero_value_invoice() {
 328                 let payment_id = PaymentId([42; 32]);
 329                 let payment_preimage = PaymentPreimage([1; 32]);
 330                 let invoice = zero_value_invoice(payment_preimage);
 331                 let amt_msat = 10_000;
 332
 333                 let payer = TestPayer::new().expect_send(Amount(amt_msat));
 334                 pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
 335         }
 336
 337         #[test]
 338         fn fails_paying_zero_value_invoice_with_amount() {
 339                 let chanmon_cfgs = create_chanmon_cfgs(1);
 340                 let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 341                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 342                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 343
 344                 let payment_preimage = PaymentPreimage([1; 32]);
 345                 let invoice = invoice(payment_preimage);
 346                 let amt_msat = 10_000;
 347
 348                 match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), &nodes[0].node) {
 349                         Err(PaymentError::Invoice("amount unexpected")) => {},
 350                         _ => panic!()
 351                 }
 352         }
 353 }