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 89087a10cd414ac9fdeae4331490ef97e73666ea..5d199269520e16c9c79464a01a86a2d55b098d8b 100644 (file)
--- a/lightning/src/blinded_path/mod.rs
+++ b/lightning/src/blinded_path/mod.rs
@@ -15,8 +15,10 @@ pub(crate) mod utils;
 
 use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey};
 
-use crate::sign::EntropySource;
 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};
 
 use crate::io;
@@ -55,15 +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];
@@ -75,25 +84,55 @@ impl BlindedPath {
                })
        }
 
-       /// Create a blinded path for a payment, to be forwarded along `path`. The last node
-       /// in `path` will be the destination node.
+       /// 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:
+       /// * a provided node id is invalid
+       /// * [`BlindedPayInfo`] calculation results in an integer overflow
+       /// * any unknown features are required in the provided [`ForwardTlvs`]
        ///
-       /// Errors if `path` is empty or a node id in `path` is invalid.
+       /// [`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>(
-               intermediate_nodes: &[(PublicKey, payment::ForwardTlvs)], payee_node_id: PublicKey,
-               payee_tlvs: payment::ReceiveTlvs, entropy_source: &ES, secp_ctx: &Secp256k1<T>
-       ) -> Result<Self, ()> {
+       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, 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");
 
-               Ok(BlindedPath {
-                       introduction_node_id: intermediate_nodes.first().map_or(payee_node_id, |n| n.0),
+               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),
                        blinded_hops: payment::blinded_hops(
                                secp_ctx, intermediate_nodes, payee_node_id, payee_tlvs, &blinding_secret
                        ).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)
        }
 }