Add BlindedPath::introduction_node_id method

[rust-lightning] / lightning / src / blinded_path / mod.rs

diff --git a/lightning/src/blinded_path/mod.rs b/lightning/src/blinded_path/mod.rs
index 927bbea9f6e99ab6e15db2cbb619af0e187060ec..5d199269520e16c9c79464a01a86a2d55b098d8b 100644 (file)
--- a/lightning/src/blinded_path/mod.rs
+++ b/lightning/src/blinded_path/mod.rs
@@ -17,6 +17,7 @@ use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey};
 
 use crate::ln::msgs::DecodeError;
 use crate::offers::invoice::BlindedPayInfo;
+use crate::routing::gossip::{NodeId, ReadOnlyNetworkGraph};
 use crate::sign::EntropySource;
 use crate::util::ser::{Readable, Writeable, Writer};
 
@@ -56,15 +57,22 @@ pub struct BlindedHop {
 }
 
 impl BlindedPath {
+       /// Create a one-hop blinded path for a message.
+       pub fn one_hop_for_message<ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification>(
+               recipient_node_id: PublicKey, entropy_source: &ES, secp_ctx: &Secp256k1<T>
+       ) -> Result<Self, ()> {
+               Self::new_for_message(&[recipient_node_id], entropy_source, secp_ctx)
+       }
+
        /// Create a blinded path for an onion message, to be forwarded along `node_pks`. The last node
        /// pubkey in `node_pks` will be the destination node.
        ///
-       /// Errors if less than two hops are provided or if `node_pk`(s) are invalid.
+       /// Errors if no hops are provided or if `node_pk`(s) are invalid.
        //  TODO: make all payloads the same size with padding + add dummy hops
-       pub fn new_for_message<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>
-               (node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1<T>) -> Result<Self, ()>
-       {
-               if node_pks.len() < 2 { return Err(()) }
+       pub fn new_for_message<ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification>(
+               node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1<T>
+       ) -> Result<Self, ()> {
+               if node_pks.is_empty() { return Err(()) }
                let blinding_secret_bytes = entropy_source.get_secure_random_bytes();
                let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
                let introduction_node_id = node_pks[0];
@@ -76,6 +84,20 @@ impl BlindedPath {
                })
        }
 
+       /// Create a one-hop blinded path for a payment.
+       pub fn one_hop_for_payment<ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification>(
+               payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, min_final_cltv_expiry_delta: u16,
+               entropy_source: &ES, secp_ctx: &Secp256k1<T>
+       ) -> Result<(BlindedPayInfo, Self), ()> {
+               // This value is not considered in pathfinding for 1-hop blinded paths, because it's intended to
+               // be in relation to a specific channel.
+               let htlc_maximum_msat = u64::max_value();
+               Self::new_for_payment(
+                       &[], payee_node_id, payee_tlvs, htlc_maximum_msat, min_final_cltv_expiry_delta,
+                       entropy_source, secp_ctx
+               )
+       }
+
        /// Create a blinded path for a payment, to be forwarded along `intermediate_nodes`.
        ///
        /// Errors if:
@@ -85,15 +107,17 @@ impl BlindedPath {
        ///
        /// [`ForwardTlvs`]: crate::blinded_path::payment::ForwardTlvs
        //  TODO: make all payloads the same size with padding + add dummy hops
-       pub fn new_for_payment<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>(
+       pub fn new_for_payment<ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification>(
                intermediate_nodes: &[payment::ForwardNode], payee_node_id: PublicKey,
-               payee_tlvs: payment::ReceiveTlvs, htlc_maximum_msat: u64, entropy_source: &ES,
-               secp_ctx: &Secp256k1<T>
+               payee_tlvs: payment::ReceiveTlvs, htlc_maximum_msat: u64, min_final_cltv_expiry_delta: u16,
+               entropy_source: &ES, secp_ctx: &Secp256k1<T>
        ) -> Result<(BlindedPayInfo, Self), ()> {
                let blinding_secret_bytes = entropy_source.get_secure_random_bytes();
                let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
 
-               let blinded_payinfo = payment::compute_payinfo(intermediate_nodes, &payee_tlvs, htlc_maximum_msat)?;
+               let blinded_payinfo = payment::compute_payinfo(
+                       intermediate_nodes, &payee_tlvs, htlc_maximum_msat, min_final_cltv_expiry_delta
+               )?;
                Ok((blinded_payinfo, BlindedPath {
                        introduction_node_id: intermediate_nodes.first().map_or(payee_node_id, |n| n.node_id),
                        blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
@@ -102,6 +126,14 @@ impl BlindedPath {
                        ).map_err(|_| ())?,
                }))
        }
+
+       /// Returns the introduction [`NodeId`] of the blinded path.
+       pub fn public_introduction_node_id<'a>(
+               &self, network_graph: &'a ReadOnlyNetworkGraph
+       ) -> Option<&'a NodeId> {
+               let node_id = NodeId::from_pubkey(&self.introduction_node_id);
+               network_graph.nodes().get_key_value(&node_id).map(|(key, _)| key)
+       }
 }
 
 impl Writeable for BlindedPath {