Include a one-hop blinded path in Offer and Refund

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 3810cfb8171eeca169e29eb5b36f68ca5b23fdfe..113d690215599d87618b535ab6259bab89635a69 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -30,6 +30,7 @@ use bitcoin::secp256k1::{SecretKey,PublicKey};
 use bitcoin::secp256k1::Secp256k1;
 use bitcoin::{LockTime, secp256k1, Sequence};
 
+use crate::blinded_path::BlindedPath;
 use crate::chain;
 use crate::chain::{Confirm, ChannelMonitorUpdateStatus, Watch, BestBlock};
 use crate::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator, LowerBoundedFeeEstimator};
@@ -7130,6 +7131,11 @@ where
        /// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer will
        /// not have an expiration unless otherwise set on the builder.
        ///
+       /// Uses a one-hop [`BlindedPath`] for the offer with [`ChannelManager::get_our_node_id`] as the
+       /// introduction node and a derived signing pubkey for recipient privacy. As such, currently,
+       /// the node must be announced. Otherwise, there is no way to find a path to the introduction
+       /// node in order to send the [`InvoiceRequest`].
+       ///
        /// [`Offer`]: crate::offers::offer::Offer
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn create_offer_builder(
@@ -7139,10 +7145,11 @@ where
                let expanded_key = &self.inbound_payment_key;
                let entropy = &*self.entropy_source;
                let secp_ctx = &self.secp_ctx;
+               let path = self.create_one_hop_blinded_path();
 
-               // TODO: Set blinded paths
                OfferBuilder::deriving_signing_pubkey(description, node_id, expanded_key, entropy, secp_ctx)
                        .chain_hash(self.chain_hash)
+                       .path(path)
        }
 
        /// Creates a [`RefundBuilder`] such that the [`Refund`] it builds is recognized by the
@@ -7152,6 +7159,11 @@ where
        ///
        /// The provided `payment_id` is used to ensure that only one invoice is paid for the refund.
        ///
+       /// Uses a one-hop [`BlindedPath`] for the refund with [`ChannelManager::get_our_node_id`] as
+       /// the introduction node and a derived payer id for sender privacy. As such, currently, the
+       /// node must be announced. Otherwise, there is no way to find a path to the introduction node
+       /// in order to send the [`Bolt12Invoice`].
+       ///
        /// [`Refund`]: crate::offers::refund::Refund
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn create_refund_builder(
@@ -7162,13 +7174,14 @@ where
                let expanded_key = &self.inbound_payment_key;
                let entropy = &*self.entropy_source;
                let secp_ctx = &self.secp_ctx;
+               let path = self.create_one_hop_blinded_path();
 
-               // TODO: Set blinded paths
                let builder = RefundBuilder::deriving_payer_id(
                        description, node_id, expanded_key, entropy, secp_ctx, amount_msats, payment_id
                )?
                        .chain_hash(self.chain_hash)
-                       .absolute_expiry(absolute_expiry);
+                       .absolute_expiry(absolute_expiry)
+                       .path(path);
 
                self.pending_outbound_payments
                        .add_new_awaiting_invoice(
@@ -7279,6 +7292,14 @@ where
                inbound_payment::get_payment_preimage(payment_hash, payment_secret, &self.inbound_payment_key)
        }
 
+       /// Creates a one-hop blinded path with [`ChannelManager::get_our_node_id`] as the introduction
+       /// node.
+       fn create_one_hop_blinded_path(&self) -> BlindedPath {
+               let entropy_source = self.entropy_source.deref();
+               let secp_ctx = &self.secp_ctx;
+               BlindedPath::one_hop_for_message(self.get_our_node_id(), 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.
        ///