Fail out-of-PaymentContext inbound keysends

Here we bubble up the payment context into PendingHTLCRouting::ReceiveKeysend
and check it when receiving a spontaneous payment prior to generating a
claimable event. Prior to this patch, we would have accepted out-of-context
keysends sent over blinded paths taken from our BOLT 12 invoices.

As a side effect of this, our blinded keysend success test cases now fail, so
those tests are now removed. Their coverage is re-added in future commits when
we add support for async receive, meaning we're able to receive blinded
keysends in the correct payment context.

Author: valentinewallace

Diff for: lightning/src/ln/async_payments_tests.rs

@@ -9,11 +9,9 @@
 
 use crate::blinded_path::message::{MessageContext, OffersContext};
 use crate::events::{Event, HTLCDestination, MessageSendEventsProvider, PaymentFailureReason};
-use crate::ln::blinded_payment_tests::{blinded_payment_path, get_blinded_route_parameters};
-use crate::ln::channelmanager;
+use crate::ln::blinded_payment_tests::get_blinded_route_parameters;
 use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
 use crate::ln::functional_test_utils::*;
-use crate::ln::inbound_payment;
 use crate::ln::msgs::ChannelMessageHandler;
 use crate::ln::msgs::OnionMessageHandler;
 use crate::ln::offers_tests;
@@ -29,11 +27,8 @@ use crate::onion_message::messenger::{Destination, MessageRouter, MessageSendIns
 use crate::onion_message::offers::OffersMessage;
 use crate::onion_message::packet::ParsedOnionMessageContents;
 use crate::prelude::*;
-use crate::routing::router::{PaymentParameters, RouteParameters};
-use crate::sign::NodeSigner;
 use crate::types::features::Bolt12InvoiceFeatures;
 use crate::types::payment::{PaymentPreimage, PaymentSecret};
-use crate::util::config::UserConfig;
 use bitcoin::secp256k1;
 use bitcoin::secp256k1::Secp256k1;
 
@@ -67,168 +62,6 @@ fn create_static_invoice<T: secp256k1::Signing + secp256k1::Verification>(
 	(offer, static_invoice)
 }
 
-#[test]
-fn blinded_keysend() {
-	let chanmon_cfgs = create_chanmon_cfgs(3);
-	let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
-	let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
-	let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
-	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
-	let chan_upd_1_2 =
-		create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0).0.contents;
-
-	let inbound_payment_key = nodes[2].keys_manager.get_inbound_payment_key();
-	let payment_secret = inbound_payment::create_for_spontaneous_payment(
-		&inbound_payment_key,
-		None,
-		u32::MAX,
-		nodes[2].node.duration_since_epoch().as_secs(),
-		None,
-	)
-	.unwrap();
-
-	let amt_msat = 5000;
-	let keysend_preimage = PaymentPreimage([42; 32]);
-	let route_params = get_blinded_route_parameters(
-		amt_msat,
-		payment_secret,
-		1,
-		1_0000_0000,
-		nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(),
-		&[&chan_upd_1_2],
-		&chanmon_cfgs[2].keys_manager,
-	);
-
-	let payment_hash = nodes[0]
-		.node
-		.send_spontaneous_payment(
-			Some(keysend_preimage),
-			RecipientOnionFields::spontaneous_empty(),
-			PaymentId(keysend_preimage.0),
-			route_params,
-			Retry::Attempts(0),
-		)
-		.unwrap();
-	check_added_monitors(&nodes[0], 1);
-
-	let expected_route: &[&[&Node]] = &[&[&nodes[1], &nodes[2]]];
-	let mut events = nodes[0].node.get_and_clear_pending_msg_events();
-	assert_eq!(events.len(), 1);
-
-	let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
-	pass_along_path(
-		&nodes[0],
-		expected_route[0],
-		amt_msat,
-		payment_hash,
-		Some(payment_secret),
-		ev.clone(),
-		true,
-		Some(keysend_preimage),
-	);
-	claim_payment_along_route(ClaimAlongRouteArgs::new(
-		&nodes[0],
-		expected_route,
-		keysend_preimage,
-	));
-}
-
-#[test]
-fn blinded_mpp_keysend() {
-	let chanmon_cfgs = create_chanmon_cfgs(4);
-	let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
-	let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
-	let nodes = create_network(4, &node_cfgs, &node_chanmgrs);
-
-	create_announced_chan_between_nodes(&nodes, 0, 1);
-	create_announced_chan_between_nodes(&nodes, 0, 2);
-	let chan_1_3 = create_announced_chan_between_nodes(&nodes, 1, 3);
-	let chan_2_3 = create_announced_chan_between_nodes(&nodes, 2, 3);
-
-	let inbound_payment_key = nodes[3].keys_manager.get_inbound_payment_key();
-	let payment_secret = inbound_payment::create_for_spontaneous_payment(
-		&inbound_payment_key,
-		None,
-		u32::MAX,
-		nodes[3].node.duration_since_epoch().as_secs(),
-		None,
-	)
-	.unwrap();
-
-	let amt_msat = 15_000_000;
-	let keysend_preimage = PaymentPreimage([42; 32]);
-	let route_params = {
-		let pay_params = PaymentParameters::blinded(vec![
-			blinded_payment_path(
-				payment_secret,
-				1,
-				1_0000_0000,
-				vec![nodes[1].node.get_our_node_id(), nodes[3].node.get_our_node_id()],
-				&[&chan_1_3.0.contents],
-				&chanmon_cfgs[3].keys_manager,
-			),
-			blinded_payment_path(
-				payment_secret,
-				1,
-				1_0000_0000,
-				vec![nodes[2].node.get_our_node_id(), nodes[3].node.get_our_node_id()],
-				&[&chan_2_3.0.contents],
-				&chanmon_cfgs[3].keys_manager,
-			),
-		])
-		.with_bolt12_features(channelmanager::provided_bolt12_invoice_features(
-			&UserConfig::default(),
-		))
-		.unwrap();
-		RouteParameters::from_payment_params_and_value(pay_params, amt_msat)
-	};
-
-	let payment_hash = nodes[0]
-		.node
-		.send_spontaneous_payment(
-			Some(keysend_preimage),
-			RecipientOnionFields::spontaneous_empty(),
-			PaymentId(keysend_preimage.0),
-			route_params,
-			Retry::Attempts(0),
-		)
-		.unwrap();
-	check_added_monitors!(nodes[0], 2);
-
-	let expected_route: &[&[&Node]] = &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]];
-	let mut events = nodes[0].node.get_and_clear_pending_msg_events();
-	assert_eq!(events.len(), 2);
-
-	let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
-	pass_along_path(
-		&nodes[0],
-		expected_route[0],
-		amt_msat,
-		payment_hash.clone(),
-		Some(payment_secret),
-		ev.clone(),
-		false,
-		Some(keysend_preimage),
-	);
-
-	let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
-	pass_along_path(
-		&nodes[0],
-		expected_route[1],
-		amt_msat,
-		payment_hash.clone(),
-		Some(payment_secret),
-		ev.clone(),
-		true,
-		Some(keysend_preimage),
-	);
-	claim_payment_along_route(ClaimAlongRouteArgs::new(
-		&nodes[0],
-		expected_route,
-		keysend_preimage,
-	));
-}
-
 #[test]
 fn invalid_keysend_payment_secret() {
 	let chanmon_cfgs = create_chanmon_cfgs(3);

Diff for: lightning/src/ln/channelmanager.rs

@@ -240,6 +240,11 @@ pub enum PendingHTLCRouting {
 		/// [`PaymentSecret`] and should verify it using our
 		/// [`NodeSigner::get_inbound_payment_key`].
 		has_recipient_created_payment_secret: bool,
+		/// The context of the payment included by the recipient in a blinded path, or `None` if a
+		/// blinded path was not used.
+		///
+		/// Used in part to determine the [`events::PaymentPurpose`].
+		payment_context: Option<PaymentContext>,
 	},
 }
 
@@ -6051,15 +6056,16 @@ where
 									PendingHTLCRouting::ReceiveKeysend {
 										payment_data, payment_preimage, payment_metadata,
 										incoming_cltv_expiry, custom_tlvs, requires_blinded_error: _,
-										has_recipient_created_payment_secret,
+										has_recipient_created_payment_secret, payment_context,
 									} => {
 										let onion_fields = RecipientOnionFields {
 											payment_secret: payment_data.as_ref().map(|data| data.payment_secret),
 											payment_metadata,
 											custom_tlvs,
 										};
 										(incoming_cltv_expiry, OnionPayload::Spontaneous(payment_preimage),
-											payment_data, None, None, onion_fields, has_recipient_created_payment_secret)
+											payment_data, payment_context, None, onion_fields,
+											has_recipient_created_payment_secret)
 									},
 									_ => {
 										panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
@@ -6256,6 +6262,12 @@ where
 										check_total_value!(purpose);
 									},
 									OnionPayload::Spontaneous(preimage) => {
+										if payment_context.is_some() {
+											if !matches!(payment_context, Some(PaymentContext::AsyncBolt12Offer(_))) {
+												log_trace!(self.logger, "Failing new HTLC with payment_hash {}: received a keysend payment to a non-async payments context {:#?}", payment_hash, payment_context);
+											}
+											fail_htlc!(claimable_htlc, payment_hash);
+										}
 										let purpose = events::PaymentPurpose::SpontaneousPayment(preimage);
 										check_total_value!(purpose);
 									}
@@ -12452,6 +12464,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
 		(4, payment_data, option), // Added in 0.0.116
 		(5, custom_tlvs, optional_vec),
 		(7, has_recipient_created_payment_secret, (default_value, false)),
+		(9, payment_context, option),
 	},
 );
 

Diff for: lightning/src/ln/offers_tests.rs

@@ -47,8 +47,8 @@ use crate::blinded_path::IntroductionNode;
 use crate::blinded_path::message::BlindedMessagePath;
 use crate::blinded_path::payment::{Bolt12OfferContext, Bolt12RefundContext, PaymentContext};
 use crate::blinded_path::message::{MessageContext, OffersContext};
-use crate::events::{ClosureReason, Event, MessageSendEventsProvider, PaymentFailureReason, PaymentPurpose};
-use crate::ln::channelmanager::{Bolt12PaymentError, MAX_SHORT_LIVED_RELATIVE_EXPIRY, PaymentId, RecentPaymentDetails, Retry, self};
+use crate::events::{ClosureReason, Event, HTLCDestination, MessageSendEventsProvider, PaymentFailureReason, PaymentPurpose};
+use crate::ln::channelmanager::{Bolt12PaymentError, MAX_SHORT_LIVED_RELATIVE_EXPIRY, PaymentId, RecentPaymentDetails, RecipientOnionFields, Retry, self};
 use crate::types::features::Bolt12InvoiceFeatures;
 use crate::ln::functional_test_utils::*;
 use crate::ln::msgs::{ChannelMessageHandler, Init, NodeAnnouncement, OnionMessage, OnionMessageHandler, RoutingMessageHandler, SocketAddress, UnsignedGossipMessage, UnsignedNodeAnnouncement};
@@ -62,6 +62,7 @@ use crate::onion_message::messenger::{Destination, PeeledOnion, MessageSendInstr
 use crate::onion_message::offers::OffersMessage;
 use crate::onion_message::packet::ParsedOnionMessageContents;
 use crate::routing::gossip::{NodeAlias, NodeId};
+use crate::routing::router::{PaymentParameters, RouteParameters};
 use crate::sign::{NodeSigner, Recipient};
 use crate::util::ser::Writeable;
 
@@ -2255,6 +2256,71 @@ fn fails_paying_invoice_with_unknown_required_features() {
 	}
 }
 
+#[test]
+fn rejects_keysend_to_non_static_invoice_path() {
+	// Test that we'll fail a keysend payment that was sent over a non-static BOLT 12 invoice path.
+	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
+
+	// First pay the offer and save the payment preimage and invoice.
+	let offer = nodes[1].node.create_offer_builder(None).unwrap().build().unwrap();
+	let amt_msat = 5000;
+	let payment_id = PaymentId([1; 32]);
+	nodes[0].node.pay_for_offer(&offer, None, Some(amt_msat), None, payment_id, Retry::Attempts(1), None).unwrap();
+	let invreq_om = nodes[0].onion_messenger.next_onion_message_for_peer(nodes[1].node.get_our_node_id()).unwrap();
+	nodes[1].onion_messenger.handle_onion_message(nodes[0].node.get_our_node_id(), &invreq_om);
+	let invoice_om = nodes[1].onion_messenger.next_onion_message_for_peer(nodes[0].node.get_our_node_id()).unwrap();
+	let invoice = extract_invoice(&nodes[0], &invoice_om).0;
+	nodes[0].onion_messenger.handle_onion_message(nodes[1].node.get_our_node_id(), &invoice_om);
+
+	route_bolt12_payment(&nodes[0], &[&nodes[1]], &invoice);
+	expect_recent_payment!(nodes[0], RecentPaymentDetails::Pending, payment_id);
+
+	let payment_preimage = match get_event!(nodes[1], Event::PaymentClaimable) {
+		Event::PaymentClaimable { purpose, .. } => purpose.preimage().unwrap(),
+		_ => panic!()
+	};
+
+	claim_payment(&nodes[0], &[&nodes[1]], payment_preimage);
+	expect_recent_payment!(&nodes[0], RecentPaymentDetails::Fulfilled, payment_id);
+
+	// Time out the payment from recent payments so we can attempt to pay it again via keysend.
+	for _ in 0..=IDEMPOTENCY_TIMEOUT_TICKS {
+		nodes[0].node.timer_tick_occurred();
+		nodes[1].node.timer_tick_occurred();
+	}
+
+	// Pay the invoice via keysend now that we have the preimage and make sure the recipient fails it
+	// due to incorrect payment context.
+	let pay_params = PaymentParameters::from_bolt12_invoice(&invoice);
+	let route_params = RouteParameters::from_payment_params_and_value(pay_params, amt_msat);
+	let keysend_payment_id = PaymentId([2; 32]);
+	let payment_hash = nodes[0].node.send_spontaneous_payment(
+		Some(payment_preimage), RecipientOnionFields::spontaneous_empty(), keysend_payment_id,
+		route_params, Retry::Attempts(0)
+	).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+	assert_eq!(events.len(), 1);
+	let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
+	let route: &[&[&Node]] = &[&[&nodes[1]]];
+
+	let args = PassAlongPathArgs::new(&nodes[0], route[0], amt_msat, payment_hash, ev)
+		.with_payment_preimage(payment_preimage)
+		.expect_failure(HTLCDestination::FailedPayment { payment_hash });
+	do_pass_along_path(args);
+	let mut updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+	nodes[0].node.handle_update_fail_htlc(nodes[1].node.get_our_node_id(), &updates.update_fail_htlcs[0]);
+	do_commitment_signed_dance(&nodes[0], &nodes[1], &updates.commitment_signed, false, false);
+	expect_payment_failed_conditions(&nodes[0], payment_hash, true, PaymentFailedConditions::new());
+	nodes[1].logger.assert_log_contains(
+		"lightning::ln::channelmanager", "received a keysend payment to a non-async payments context", 1
+	);
+}
+
 #[test]
 fn no_double_pay_with_stale_channelmanager() {
 	// This tests the following bug:

Diff for: lightning/src/ln/onion_payment.rs

@@ -235,6 +235,7 @@ pub(super) fn create_recv_pending_htlc_info(
 			custom_tlvs,
 			requires_blinded_error,
 			has_recipient_created_payment_secret,
+			payment_context,
 		}
 	} else if let Some(data) = payment_data {
 		PendingHTLCRouting::Receive {