Support phantom payment receive in ChannelManager, with invoice util
[rust-lightning] / lightning-invoice / src / utils.rs
index 1b55c34e444c79b2b44f26fe0ea81059ed518313..fc82541a564e8cbd82c64f75fd37d4fa87ecd8af 100644 (file)
@@ -10,7 +10,7 @@ use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use lightning::chain::keysinterface::{Recipient, KeysInterface, Sign};
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, PaymentId, PaymentSendFailure, MIN_FINAL_CLTV_EXPIRY};
+use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, PaymentId, PaymentSendFailure, PhantomRouteHints, MIN_FINAL_CLTV_EXPIRY, MIN_CLTV_EXPIRY_DELTA};
 use lightning::ln::msgs::LightningError;
 use lightning::routing::scoring::Score;
 use lightning::routing::network_graph::{NetworkGraph, RoutingFees};
@@ -21,6 +21,99 @@ use core::convert::TryInto;
 use core::ops::Deref;
 use core::time::Duration;
 
+#[cfg(feature = "std")]
+/// Utility to create an invoice that can be paid to one of multiple nodes, or a "phantom invoice."
+/// See [`PhantomKeysManager`] for more information on phantom node payments.
+///
+/// `phantom_route_hints` parameter:
+/// * Contains channel info for all nodes participating in the phantom invoice
+/// * Entries are retrieved from a call to [`ChannelManager::get_phantom_route_hints`] on each
+///   participating node
+/// * It is fine to cache `phantom_route_hints` and reuse it across invoices, as long as the data is
+///   updated when a channel becomes disabled or closes
+/// * Note that if too many channels are included in [`PhantomRouteHints::channels`], the invoice
+///   may be too long for QR code scanning. To fix this, `PhantomRouteHints::channels` may be pared
+///   down
+///
+/// `payment_hash` and `payment_secret` come from [`ChannelManager::create_inbound_payment`] or
+/// [`ChannelManager::create_inbound_payment_for_hash`]. These values can be retrieved from any
+/// participating node.
+///
+/// Note that the provided `keys_manager`'s `KeysInterface` implementation must support phantom
+/// invoices in its `sign_invoice` implementation ([`PhantomKeysManager`] satisfies this
+/// requirement).
+///
+/// [`PhantomKeysManager`]: lightning::chain::keysinterface::PhantomKeysManager
+/// [`ChannelManager::get_phantom_route_hints`]: lightning::ln::channelmanager::ChannelManager::get_phantom_route_hints
+/// [`PhantomRouteHints::channels`]: lightning::ln::channelmanager::PhantomRouteHints::channels
+pub fn create_phantom_invoice<Signer: Sign, K: Deref>(
+       amt_msat: Option<u64>, description: String, payment_hash: PaymentHash, payment_secret:
+       PaymentSecret, phantom_route_hints: Vec<PhantomRouteHints>, keys_manager: K, network: Currency
+) -> Result<Invoice, SignOrCreationError<()>> where K::Target: KeysInterface {
+       if phantom_route_hints.len() == 0 {
+               return Err(SignOrCreationError::CreationError(CreationError::MissingRouteHints))
+       }
+       let mut invoice = InvoiceBuilder::new(network)
+               .description(description)
+               .current_timestamp()
+               .payment_hash(Hash::from_slice(&payment_hash.0).unwrap())
+               .payment_secret(payment_secret)
+               .min_final_cltv_expiry(MIN_FINAL_CLTV_EXPIRY.into());
+       if let Some(amt) = amt_msat {
+               invoice = invoice.amount_milli_satoshis(amt);
+       }
+
+       for hint in phantom_route_hints {
+               for channel in &hint.channels {
+                       let short_channel_id = match channel.short_channel_id {
+                               Some(id) => id,
+                               None => continue,
+                       };
+                       let forwarding_info = match &channel.counterparty.forwarding_info {
+                               Some(info) => info.clone(),
+                               None => continue,
+                       };
+                       invoice = invoice.private_route(RouteHint(vec![
+                                       RouteHintHop {
+                                               src_node_id: channel.counterparty.node_id,
+                                               short_channel_id,
+                                               fees: RoutingFees {
+                                                       base_msat: forwarding_info.fee_base_msat,
+                                                       proportional_millionths: forwarding_info.fee_proportional_millionths,
+                                               },
+                                               cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
+                                               htlc_minimum_msat: None,
+                                               htlc_maximum_msat: None,
+                                       },
+                                       RouteHintHop {
+                                               src_node_id: hint.real_node_pubkey,
+                                               short_channel_id: hint.phantom_scid,
+                                               fees: RoutingFees {
+                                                       base_msat: 0,
+                                                       proportional_millionths: 0,
+                                               },
+                                               cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
+                                               htlc_minimum_msat: None,
+                                               htlc_maximum_msat: None,
+                                       }])
+                       );
+               }
+       }
+
+       let raw_invoice = match invoice.build_raw() {
+               Ok(inv) => inv,
+               Err(e) => return Err(SignOrCreationError::CreationError(e))
+       };
+       let hrp_str = raw_invoice.hrp.to_string();
+       let hrp_bytes = hrp_str.as_bytes();
+       let data_without_signature = raw_invoice.data.to_base32();
+       let signed_raw_invoice = raw_invoice.sign(|_| keys_manager.sign_invoice(hrp_bytes, &data_without_signature, Recipient::PhantomNode));
+       match signed_raw_invoice {
+               Ok(inv) => Ok(Invoice::from_signed(inv).unwrap()),
+               Err(e) => Err(SignOrCreationError::SignError(e))
+       }
+}
+
 #[cfg(feature = "std")]
 /// Utility to construct an invoice. Generally, unless you want to do something like a custom
 /// cltv_expiry, this is what you should be using to create an invoice. The reason being, this
@@ -192,13 +285,17 @@ where
 mod test {
        use core::time::Duration;
        use {Currency, Description, InvoiceDescription};
-       use lightning::ln::PaymentHash;
+       use bitcoin_hashes::Hash;
+       use bitcoin_hashes::sha256::Hash as Sha256;
+       use lightning::chain::keysinterface::PhantomKeysManager;
+       use lightning::ln::{PaymentPreimage, PaymentHash};
        use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY;
        use lightning::ln::functional_test_utils::*;
        use lightning::ln::features::InitFeatures;
        use lightning::ln::msgs::ChannelMessageHandler;
        use lightning::routing::router::{PaymentParameters, RouteParameters, find_route};
-       use lightning::util::events::MessageSendEventsProvider;
+       use lightning::util::enforcing_trait_impls::EnforcingSigner;
+       use lightning::util::events::{MessageSendEvent, MessageSendEventsProvider, Event};
        use lightning::util::test_utils;
        use utils::create_invoice_from_channelmanager_and_duration_since_epoch;
 
@@ -254,4 +351,121 @@ mod test {
                let events = nodes[1].node.get_and_clear_pending_msg_events();
                assert_eq!(events.len(), 2);
        }
+
+       #[test]
+       #[cfg(feature = "std")]
+       fn test_multi_node_receive() {
+               do_test_multi_node_receive(true);
+               do_test_multi_node_receive(false);
+       }
+
+       #[cfg(feature = "std")]
+       fn do_test_multi_node_receive(user_generated_pmt_hash: bool) {
+               let mut chanmon_cfgs = create_chanmon_cfgs(3);
+               let seed_1 = [42 as u8; 32];
+               let seed_2 = [43 as u8; 32];
+               let cross_node_seed = [44 as u8; 32];
+               chanmon_cfgs[1].keys_manager.backing = PhantomKeysManager::new(&seed_1, 43, 44, &cross_node_seed);
+               chanmon_cfgs[2].keys_manager.backing = PhantomKeysManager::new(&seed_2, 43, 44, &cross_node_seed);
+               let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+               let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+               let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+               let chan_0_1 = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+               nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan_0_1.1);
+               nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &chan_0_1.0);
+               let chan_0_2 = create_announced_chan_between_nodes_with_value(&nodes, 0, 2, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+               nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan_0_2.1);
+               nodes[2].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &chan_0_2.0);
+
+               let payment_amt = 10_000;
+               let (payment_preimage, payment_hash, payment_secret) = {
+                       if user_generated_pmt_hash {
+                               let payment_preimage = PaymentPreimage([1; 32]);
+                               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner());
+                               let payment_secret = nodes[1].node.create_inbound_payment_for_hash(payment_hash, Some(payment_amt), 3600).unwrap();
+                               (payment_preimage, payment_hash, payment_secret)
+                       } else {
+                               let (payment_hash, payment_secret) = nodes[1].node.create_inbound_payment(Some(payment_amt), 3600).unwrap();
+                               let payment_preimage = nodes[1].node.get_payment_preimage(payment_hash, payment_secret).unwrap();
+                               (payment_preimage, payment_hash, payment_secret)
+                       }
+               };
+               let route_hints = vec![
+                       nodes[1].node.get_phantom_route_hints(),
+                       nodes[2].node.get_phantom_route_hints(),
+               ];
+               let invoice = ::utils::create_phantom_invoice::<EnforcingSigner, &test_utils::TestKeysInterface>(Some(payment_amt), "test".to_string(), payment_hash, payment_secret, route_hints, &nodes[1].keys_manager, Currency::BitcoinTestnet).unwrap();
+
+               assert_eq!(invoice.min_final_cltv_expiry(), MIN_FINAL_CLTV_EXPIRY as u64);
+               assert_eq!(invoice.description(), InvoiceDescription::Direct(&Description("test".to_string())));
+               assert_eq!(invoice.route_hints().len(), 2);
+               assert!(!invoice.features().unwrap().supports_basic_mpp());
+
+               let payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
+                       .with_features(invoice.features().unwrap().clone())
+                       .with_route_hints(invoice.route_hints());
+               let params = RouteParameters {
+                       payment_params,
+                       final_value_msat: invoice.amount_milli_satoshis().unwrap(),
+                       final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
+               };
+               let first_hops = nodes[0].node.list_usable_channels();
+               let network_graph = node_cfgs[0].network_graph;
+               let logger = test_utils::TestLogger::new();
+               let scorer = test_utils::TestScorer::with_penalty(0);
+               let route = find_route(
+                       &nodes[0].node.get_our_node_id(), &params, network_graph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), &logger, &scorer,
+               ).unwrap();
+               let (payment_event, fwd_idx) = {
+                       let mut payment_hash = PaymentHash([0; 32]);
+                       payment_hash.0.copy_from_slice(&invoice.payment_hash().as_ref()[0..32]);
+                       nodes[0].node.send_payment(&route, payment_hash, &Some(invoice.payment_secret().clone())).unwrap();
+                       let mut added_monitors = nodes[0].chain_monitor.added_monitors.lock().unwrap();
+                       assert_eq!(added_monitors.len(), 1);
+                       added_monitors.clear();
+
+                       let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+                       assert_eq!(events.len(), 1);
+                       let fwd_idx = match events[0] {
+                               MessageSendEvent::UpdateHTLCs { node_id, .. } => {
+                                       if node_id == nodes[1].node.get_our_node_id() {
+                                               1
+                                       } else { 2 }
+                               },
+                               _ => panic!("Unexpected event")
+                       };
+                       (SendEvent::from_event(events.remove(0)), fwd_idx)
+               };
+               nodes[fwd_idx].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
+               commitment_signed_dance!(nodes[fwd_idx], nodes[0], &payment_event.commitment_msg, false, true);
+
+               // Note that we have to "forward pending HTLCs" twice before we see the PaymentReceived as
+               // this "emulates" the payment taking two hops, providing some privacy to make phantom node
+               // payments "look real" by taking more time.
+               expect_pending_htlcs_forwardable_ignore!(nodes[fwd_idx]);
+               nodes[fwd_idx].node.process_pending_htlc_forwards();
+               expect_pending_htlcs_forwardable_ignore!(nodes[fwd_idx]);
+               nodes[fwd_idx].node.process_pending_htlc_forwards();
+
+               let payment_preimage_opt = if user_generated_pmt_hash { None } else { Some(payment_preimage) };
+               expect_payment_received!(&nodes[fwd_idx], payment_hash, payment_secret, payment_amt, payment_preimage_opt);
+               do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[fwd_idx])[..]), false, payment_preimage);
+               let events = nodes[0].node.get_and_clear_pending_events();
+               assert_eq!(events.len(), 2);
+               match events[0] {
+                       Event::PaymentSent { payment_preimage: ref ev_preimage, payment_hash: ref ev_hash, ref fee_paid_msat, .. } => {
+                               assert_eq!(payment_preimage, *ev_preimage);
+                               assert_eq!(payment_hash, *ev_hash);
+                               assert_eq!(fee_paid_msat, &Some(0));
+                       },
+                       _ => panic!("Unexpected event")
+               }
+               match events[1] {
+                       Event::PaymentPathSuccessful { payment_hash: hash, .. } => {
+                               assert_eq!(hash, Some(payment_hash));
+                       },
+                       _ => panic!("Unexpected event")
+               }
+       }
 }