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};
#[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.
///
pub blinded_hops: Vec<BlindedHop>,
}
+/// 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.
}
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];
+ 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 one-hop blinded path for a payment.
- pub fn one_hop_for_payment<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>(
- payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, entropy_source: &ES,
- secp_ctx: &Secp256k1<T>
+ 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, entropy_source, secp_ctx
+ &[], payee_node_id, payee_tlvs, htlc_maximum_msat, min_final_cltv_expiry_delta,
+ entropy_source, secp_ctx
)
}
///
/// [`ForwardTlvs`]: crate::blinded_path::payment::ForwardTlvs
// TODO: make all payloads the same size with padding + add dummy hops
- pub(crate) 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 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");
- 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),
+ 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<W: Writer>(&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 {
impl Readable for BlindedPath {
fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
- 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) }
blinded_hops.push(Readable::read(r)?);
}
Ok(BlindedPath {
- introduction_node_id,
+ introduction_node,
blinding_point,
blinded_hops,
})
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),
+ }
+ }
+}