X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fblinded_path%2Fmod.rs;h=daa9f033d94e4f0b5544c8cc71bb6e7523ca8acb;hb=7002180261d495f15c12f9a341af1e7dbcac2990;hp=89087a10cd414ac9fdeae4331490ef97e73666ea;hpb=0211daa48ba8233ad7dbf2864ca72e0150051c68;p=rust-lightning diff --git a/lightning/src/blinded_path/mod.rs b/lightning/src/blinded_path/mod.rs index 89087a10..daa9f033 100644 --- 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; @@ -27,11 +29,11 @@ use crate::prelude::*; #[derive(Clone, Debug, Hash, PartialEq, Eq)] pub struct BlindedPath { /// To send to a blinded path, the sender first finds a route to the unblinded - /// `introduction_node_id`, which can unblind its [`encrypted_payload`] to find out the onion + /// `introduction_node`, which can unblind its [`encrypted_payload`] to find out the onion /// message or payment's next hop and forward it along. /// /// [`encrypted_payload`]: BlindedHop::encrypted_payload - pub introduction_node_id: PublicKey, + pub introduction_node: IntroductionNode, /// Used by the introduction node to decrypt its [`encrypted_payload`] to forward the onion /// message or payment. /// @@ -41,6 +43,29 @@ pub struct BlindedPath { pub blinded_hops: Vec, } +/// The unblinded node in a [`BlindedPath`]. +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +pub enum IntroductionNode { + /// The node id of the introduction node. + NodeId(PublicKey), + /// The short channel id of the channel leading to the introduction node. The [`Direction`] + /// identifies which side of the channel is the introduction node. + DirectedShortChannelId(Direction, u64), +} + +/// The side of a channel that is the [`IntroductionNode`] in a [`BlindedPath`]. [BOLT 7] defines +/// which nodes is which in the [`ChannelAnnouncement`] message. +/// +/// [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)] +pub enum Direction { + /// The lesser node id when compared lexicographically in ascending order. + NodeOne, + /// The greater node id when compared lexicographically in ascending order. + NodeTwo, +} + /// 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. @@ -55,51 +80,114 @@ 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) + } + /// 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 - (node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1) -> Result - { - if node_pks.len() < 2 { return Err(()) } + pub fn new_for_message( + node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1 + ) -> Result { + 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]; + let introduction_node = IntroductionNode::NodeId(node_pks[0]); Ok(BlindedPath { - introduction_node_id, + 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(|_| ())?, }) } - /// 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( + payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, min_final_cltv_expiry_delta: u16, + entropy_source: &ES, secp_ctx: &Secp256k1 + ) -> 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( - intermediate_nodes: &[(PublicKey, payment::ForwardTlvs)], payee_node_id: PublicKey, - payee_tlvs: payment::ReceiveTlvs, entropy_source: &ES, secp_ctx: &Secp256k1 - ) -> Result { + 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), ()> { + let introduction_node = IntroductionNode::NodeId( + intermediate_nodes.first().map_or(payee_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"); - 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, 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, if it is publicly reachable (i.e., + /// it is found in the network graph). + pub fn public_introduction_node_id<'a>( + &self, network_graph: &'a ReadOnlyNetworkGraph + ) -> Option<&'a NodeId> { + match &self.introduction_node { + IntroductionNode::NodeId(pubkey) => { + let node_id = NodeId::from_pubkey(pubkey); + network_graph.nodes().get_key_value(&node_id).map(|(key, _)| key) + }, + IntroductionNode::DirectedShortChannelId(direction, scid) => { + network_graph + .channel(*scid) + .map(|c| match direction { + Direction::NodeOne => &c.node_one, + Direction::NodeTwo => &c.node_two, + }) + }, + } } } impl Writeable for BlindedPath { fn write(&self, w: &mut W) -> Result<(), io::Error> { - self.introduction_node_id.write(w)?; + match &self.introduction_node { + IntroductionNode::NodeId(pubkey) => pubkey.write(w)?, + IntroductionNode::DirectedShortChannelId(direction, scid) => { + match direction { + Direction::NodeOne => 0u8.write(w)?, + Direction::NodeTwo => 1u8.write(w)?, + } + scid.write(w)?; + }, + } + self.blinding_point.write(w)?; (self.blinded_hops.len() as u8).write(w)?; for hop in &self.blinded_hops { @@ -111,7 +199,17 @@ impl Writeable for BlindedPath { impl Readable for BlindedPath { fn read(r: &mut R) -> Result { - let introduction_node_id = Readable::read(r)?; + let mut first_byte: u8 = Readable::read(r)?; + let introduction_node = match first_byte { + 0 => IntroductionNode::DirectedShortChannelId(Direction::NodeOne, Readable::read(r)?), + 1 => IntroductionNode::DirectedShortChannelId(Direction::NodeTwo, Readable::read(r)?), + 2|3 => { + use io::Read; + let mut pubkey_read = core::slice::from_mut(&mut first_byte).chain(r.by_ref()); + IntroductionNode::NodeId(Readable::read(&mut pubkey_read)?) + }, + _ => return Err(DecodeError::InvalidValue), + }; let blinding_point = Readable::read(r)?; let num_hops: u8 = Readable::read(r)?; if num_hops == 0 { return Err(DecodeError::InvalidValue) } @@ -120,7 +218,7 @@ impl Readable for BlindedPath { blinded_hops.push(Readable::read(r)?); } Ok(BlindedPath { - introduction_node_id, + introduction_node, blinding_point, blinded_hops, }) @@ -132,3 +230,12 @@ impl_writeable!(BlindedHop, { encrypted_payload }); +impl Direction { + /// Returns the [`NodeId`] from the inputs corresponding to the direction. + pub fn select_node_id<'a>(&self, node_a: &'a NodeId, node_b: &'a NodeId) -> &'a NodeId { + match self { + Direction::NodeOne => core::cmp::min(node_a, node_b), + Direction::NodeTwo => core::cmp::max(node_a, node_b), + } + } +}