From 46b794e9a2bba2a94b3cb1f06182903d1fab4ad4 Mon Sep 17 00:00:00 2001 From: Jeffrey Czyz Date: Fri, 15 Sep 2023 13:40:41 -0500 Subject: [PATCH] Utility for creating and sending Bolt12Invoices Add a utility to ChannelManager for creating a Bolt12Invoice for a Refund such that the ChannelManager can recognize the PaymentHash and reconstruct the PaymentPreimage from the PaymentSecret, the latter of which is contained in a BlindedPath within the invoice. --- lightning/src/blinded_path/mod.rs | 4 +- lightning/src/ln/channelmanager.rs | 88 +++++++++++++++++++++++++++++- 2 files changed, 89 insertions(+), 3 deletions(-) diff --git a/lightning/src/blinded_path/mod.rs b/lightning/src/blinded_path/mod.rs index 1415836c0..d75b4f25b 100644 --- a/lightning/src/blinded_path/mod.rs +++ b/lightning/src/blinded_path/mod.rs @@ -84,7 +84,7 @@ impl BlindedPath { } /// Create a one-hop blinded path for a payment. - pub fn one_hop_for_payment( + pub fn one_hop_for_payment( payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, entropy_source: &ES, secp_ctx: &Secp256k1 ) -> Result<(BlindedPayInfo, Self), ()> { @@ -105,7 +105,7 @@ impl BlindedPath { /// /// [`ForwardTlvs`]: crate::blinded_path::payment::ForwardTlvs // TODO: make all payloads the same size with padding + add dummy hops - pub(crate) fn new_for_payment( + pub(crate) fn new_for_payment( intermediate_nodes: &[payment::ForwardNode], payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, htlc_maximum_msat: u64, entropy_source: &ES, secp_ctx: &Secp256k1 diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 3e7bac3d4..2df3b5d41 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -31,6 +31,7 @@ use bitcoin::secp256k1::Secp256k1; use bitcoin::{LockTime, secp256k1, Sequence}; use crate::blinded_path::BlindedPath; +use crate::blinded_path::payment::{PaymentConstraints, ReceiveTlvs}; use crate::chain; use crate::chain::{Confirm, ChannelMonitorUpdateStatus, Watch, BestBlock}; use crate::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator, LowerBoundedFeeEstimator}; @@ -56,9 +57,10 @@ use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError}; use crate::ln::outbound_payment; use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration}; use crate::ln::wire::Encode; +use crate::offers::invoice::{BlindedPayInfo, DEFAULT_RELATIVE_EXPIRY}; use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder}; use crate::offers::parse::Bolt12SemanticError; -use crate::offers::refund::RefundBuilder; +use crate::offers::refund::{Refund, RefundBuilder}; use crate::onion_message::{Destination, OffersMessage, PendingOnionMessage}; use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, WriteableEcdsaChannelSigner}; use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate}; @@ -7445,6 +7447,67 @@ where Ok(()) } + /// Creates a [`Bolt12Invoice`] for a [`Refund`] and enqueues it to be sent via an onion + /// message. + /// + /// The resulting invoice uses a [`PaymentHash`] recognized by the [`ChannelManager`] and a + /// [`BlindedPath`] containing the [`PaymentSecret`] needed to reconstruct the corresponding + /// [`PaymentPreimage`]. + /// + /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice + pub fn request_refund_payment(&self, refund: &Refund) -> Result<(), Bolt12SemanticError> { + let expanded_key = &self.inbound_payment_key; + let entropy = &*self.entropy_source; + let secp_ctx = &self.secp_ctx; + + let amount_msats = refund.amount_msats(); + let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32; + + match self.create_inbound_payment(Some(amount_msats), relative_expiry, None) { + Ok((payment_hash, payment_secret)) => { + let payment_paths = vec![ + self.create_one_hop_blinded_payment_path(payment_secret), + ]; + #[cfg(not(feature = "no-std"))] + let builder = refund.respond_using_derived_keys( + payment_paths, payment_hash, expanded_key, entropy + )?; + #[cfg(feature = "no-std")] + let created_at = Duration::from_secs( + self.highest_seen_timestamp.load(Ordering::Acquire) as u64 + ); + #[cfg(feature = "no-std")] + let builder = refund.respond_using_derived_keys_no_std( + payment_paths, payment_hash, created_at, expanded_key, entropy + )?; + let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?; + let reply_path = self.create_one_hop_blinded_path(); + + let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap(); + if refund.paths().is_empty() { + let message = PendingOnionMessage { + contents: OffersMessage::Invoice(invoice), + destination: Destination::Node(refund.payer_id()), + reply_path: Some(reply_path), + }; + pending_offers_messages.push(message); + } else { + for path in refund.paths() { + let message = PendingOnionMessage { + contents: OffersMessage::Invoice(invoice.clone()), + destination: Destination::BlindedPath(path.clone()), + reply_path: Some(reply_path.clone()), + }; + pending_offers_messages.push(message); + } + } + + Ok(()) + }, + Err(()) => Err(Bolt12SemanticError::InvalidAmount), + } + } + /// Gets a payment secret and payment hash for use in an invoice given to a third party wishing /// to pay us. /// @@ -7553,6 +7616,29 @@ where BlindedPath::one_hop_for_message(self.get_our_node_id(), entropy_source, secp_ctx).unwrap() } + /// Creates a one-hop blinded path with [`ChannelManager::get_our_node_id`] as the introduction + /// node. + fn create_one_hop_blinded_payment_path( + &self, payment_secret: PaymentSecret + ) -> (BlindedPayInfo, BlindedPath) { + let entropy_source = self.entropy_source.deref(); + let secp_ctx = &self.secp_ctx; + + let payee_node_id = self.get_our_node_id(); + let max_cltv_expiry = self.best_block.read().unwrap().height() + LATENCY_GRACE_PERIOD_BLOCKS; + let payee_tlvs = ReceiveTlvs { + payment_secret, + payment_constraints: PaymentConstraints { + max_cltv_expiry, + htlc_minimum_msat: 1, + }, + }; + // TODO: Err for overflow? + BlindedPath::one_hop_for_payment( + payee_node_id, payee_tlvs, entropy_source, secp_ctx + ).unwrap() + } + /// Gets a fake short channel id for use in receiving [phantom node payments]. These fake scids /// are used when constructing the phantom invoice's route hints. /// -- 2.39.5