X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fblinded_path%2Fmod.rs;h=5abf53ec166561b351c17255eeaf7424cf2677fb;hb=d792afb08cdc20a30786728c3bfe816dd3b59e47;hp=daa9f033d94e4f0b5544c8cc71bb6e7523ca8acb;hpb=7002180261d495f15c12f9a341af1e7dbcac2990;p=rust-lightning diff --git a/lightning/src/blinded_path/mod.rs b/lightning/src/blinded_path/mod.rs index daa9f033..5abf53ec 100644 --- a/lightning/src/blinded_path/mod.rs +++ b/lightning/src/blinded_path/mod.rs @@ -10,10 +10,11 @@ //! Creating blinded paths and related utilities live here. pub mod payment; -pub(crate) mod message; +pub mod message; pub(crate) mod utils; use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey}; +use core::ops::Deref; use crate::ln::msgs::DecodeError; use crate::offers::invoice::BlindedPayInfo; @@ -24,6 +25,17 @@ use crate::util::ser::{Readable, Writeable, Writer}; use crate::io; use crate::prelude::*; +/// The next hop to forward an onion message along its path. +/// +/// Note that payment blinded paths always specify their next hop using an explicit node id. +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +pub enum NextMessageHop { + /// The node id of the next hop. + NodeId(PublicKey), + /// The short channel id leading to the next hop. + ShortChannelId(u64), +} + /// Onion messages and payments can be sent and received to blinded paths, which serve to hide the /// identity of the recipient. #[derive(Clone, Debug, Hash, PartialEq, Eq)] @@ -58,7 +70,7 @@ pub enum IntroductionNode { /// /// [BOLT 7]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_announcement-message /// [`ChannelAnnouncement`]: crate::ln::msgs::ChannelAnnouncement -#[derive(Clone, Debug, Hash, PartialEq, Eq)] +#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)] pub enum Direction { /// The lesser node id when compared lexicographically in ascending order. NodeOne, @@ -66,6 +78,34 @@ pub enum Direction { NodeTwo, } +/// An interface for looking up the node id of a channel counterparty for the purpose of forwarding +/// an [`OnionMessage`]. +/// +/// [`OnionMessage`]: crate::ln::msgs::OnionMessage +pub trait NodeIdLookUp { + /// Returns the node id of the forwarding node's channel counterparty with `short_channel_id`. + /// + /// Here, the forwarding node is referring to the node of the [`OnionMessenger`] parameterized + /// by the [`NodeIdLookUp`] and the counterparty to one of that node's peers. + /// + /// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger + fn next_node_id(&self, short_channel_id: u64) -> Option; +} + +/// A [`NodeIdLookUp`] that always returns `None`. +pub struct EmptyNodeIdLookUp {} + +impl NodeIdLookUp for EmptyNodeIdLookUp { + fn next_node_id(&self, _short_channel_id: u64) -> Option { + None + } +} + +impl Deref for EmptyNodeIdLookUp { + type Target = EmptyNodeIdLookUp; + fn deref(&self) -> &Self { self } +} + /// An encrypted payload and node id corresponding to a hop in a payment or onion message path, to /// be encoded in the sender's onion packet. These hops cannot be identified by outside observers /// and thus can be used to hide the identity of the recipient. @@ -81,10 +121,10 @@ pub struct BlindedHop { impl BlindedPath { /// Create a one-hop blinded path for a message. - pub fn one_hop_for_message( - recipient_node_id: PublicKey, entropy_source: &ES, secp_ctx: &Secp256k1 - ) -> Result { - Self::new_for_message(&[recipient_node_id], entropy_source, secp_ctx) + pub fn one_hop_for_message( + recipient_node_id: PublicKey, entropy_source: ES, secp_ctx: &Secp256k1 + ) -> Result where ES::Target: EntropySource { + 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 @@ -92,26 +132,30 @@ impl BlindedPath { /// /// 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( - node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1 - ) -> Result { - if node_pks.is_empty() { return Err(()) } + pub fn new_for_message( + intermediate_nodes: &[message::ForwardNode], recipient_node_id: PublicKey, + entropy_source: ES, secp_ctx: &Secp256k1 + ) -> Result where ES::Target: EntropySource { + let introduction_node = IntroductionNode::NodeId( + intermediate_nodes.first().map_or(recipient_node_id, |n| n.node_id) + ); 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 = IntroductionNode::NodeId(node_pks[0]); Ok(BlindedPath { introduction_node, blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret), - blinded_hops: message::blinded_hops(secp_ctx, node_pks, &blinding_secret).map_err(|_| ())?, + blinded_hops: message::blinded_hops( + secp_ctx, intermediate_nodes, recipient_node_id, &blinding_secret, + ).map_err(|_| ())?, }) } /// 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, min_final_cltv_expiry_delta: u16, - entropy_source: &ES, secp_ctx: &Secp256k1 - ) -> Result<(BlindedPayInfo, Self), ()> { + entropy_source: ES, secp_ctx: &Secp256k1 + ) -> Result<(BlindedPayInfo, Self), ()> where ES::Target: EntropySource { // 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(); @@ -130,11 +174,11 @@ 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( + pub fn new_for_payment( 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 - ) -> Result<(BlindedPayInfo, Self), ()> { + entropy_source: ES, secp_ctx: &Secp256k1 + ) -> Result<(BlindedPayInfo, Self), ()> where ES::Target: EntropySource { let introduction_node = IntroductionNode::NodeId( intermediate_nodes.first().map_or(payee_node_id, |n| n.node_id) ); @@ -238,4 +282,17 @@ impl Direction { Direction::NodeTwo => core::cmp::max(node_a, node_b), } } + + /// Returns the [`PublicKey`] from the inputs corresponding to the direction. + pub fn select_pubkey<'a>(&self, node_a: &'a PublicKey, node_b: &'a PublicKey) -> &'a PublicKey { + let (node_one, node_two) = if NodeId::from_pubkey(node_a) < NodeId::from_pubkey(node_b) { + (node_a, node_b) + } else { + (node_b, node_a) + }; + match self { + Direction::NodeOne => node_one, + Direction::NodeTwo => node_two, + } + } }