+//! Data structures and methods for constructing [`BlindedPath`]s to send a message over.
+//!
+//! [`BlindedPath`]: crate::blinded_path::BlindedPath
+
use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey};
-use crate::blinded_path::{BlindedHop, BlindedPath};
+#[allow(unused_imports)]
+use crate::prelude::*;
+
+use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode, NextMessageHop, NodeIdLookUp};
use crate::blinded_path::utils;
use crate::io;
use crate::io::Cursor;
use crate::ln::onion_utils;
-use crate::onion_message::ControlTlvs;
-use crate::prelude::*;
+use crate::onion_message::packet::ControlTlvs;
use crate::sign::{NodeSigner, Recipient};
-use crate::util::chacha20poly1305rfc::ChaChaPolyReadAdapter;
+use crate::crypto::streams::ChaChaPolyReadAdapter;
use crate::util::ser::{FixedLengthReader, LengthReadableArgs, Writeable, Writer};
use core::mem;
use core::ops::Deref;
+/// An intermediate node, and possibly a short channel id leading to the next node.
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
+pub struct ForwardNode {
+ /// This node's pubkey.
+ pub node_id: PublicKey,
+ /// The channel between `node_id` and the next hop. If set, the constructed [`BlindedHop`]'s
+ /// `encrypted_payload` will use this instead of the next [`ForwardNode::node_id`] for a more
+ /// compact representation.
+ pub short_channel_id: Option<u64>,
+}
+
/// TLVs to encode in an intermediate onion message packet's hop data. When provided in a blinded
/// route, they are encoded into [`BlindedHop::encrypted_payload`].
pub(crate) struct ForwardTlvs {
- /// The node id of the next hop in the onion message's path.
- pub(crate) next_node_id: PublicKey,
+ /// The next hop in the onion message's path.
+ pub(crate) next_hop: NextMessageHop,
/// Senders to a blinded path use this value to concatenate the route they find to the
/// introduction node with the blinded path.
pub(crate) next_blinding_override: Option<PublicKey>,
impl Writeable for ForwardTlvs {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+ let (next_node_id, short_channel_id) = match self.next_hop {
+ NextMessageHop::NodeId(pubkey) => (Some(pubkey), None),
+ NextMessageHop::ShortChannelId(scid) => (None, Some(scid)),
+ };
// TODO: write padding
encode_tlv_stream!(writer, {
- (4, self.next_node_id, required),
+ (2, short_channel_id, option),
+ (4, next_node_id, option),
(8, self.next_blinding_override, option)
});
Ok(())
}
}
-/// Construct blinded onion message hops for the given `unblinded_path`.
+/// Construct blinded onion message hops for the given `intermediate_nodes` and `recipient_node_id`.
pub(super) fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
- secp_ctx: &Secp256k1<T>, unblinded_path: &[PublicKey], session_priv: &SecretKey
+ secp_ctx: &Secp256k1<T>, intermediate_nodes: &[ForwardNode], recipient_node_id: PublicKey,
+ session_priv: &SecretKey
) -> Result<Vec<BlindedHop>, secp256k1::Error> {
- let mut blinded_hops = Vec::with_capacity(unblinded_path.len());
-
- let mut prev_ss_and_blinded_node_id = None;
- utils::construct_keys_callback(secp_ctx, unblinded_path, None, session_priv, |blinded_node_id, _, _, encrypted_payload_ss, unblinded_pk, _| {
- if let Some((prev_ss, prev_blinded_node_id)) = prev_ss_and_blinded_node_id {
- if let Some(pk) = unblinded_pk {
- let payload = ForwardTlvs {
- next_node_id: pk,
- next_blinding_override: None,
- };
- blinded_hops.push(BlindedHop {
- blinded_node_id: prev_blinded_node_id,
- encrypted_payload: utils::encrypt_payload(payload, prev_ss),
- });
- } else { debug_assert!(false); }
- }
- prev_ss_and_blinded_node_id = Some((encrypted_payload_ss, blinded_node_id));
- })?;
+ let pks = intermediate_nodes.iter().map(|node| &node.node_id)
+ .chain(core::iter::once(&recipient_node_id));
+ let tlvs = pks.clone()
+ .skip(1) // The first node's TLVs contains the next node's pubkey
+ .zip(intermediate_nodes.iter().map(|node| node.short_channel_id))
+ .map(|(pubkey, scid)| match scid {
+ Some(scid) => NextMessageHop::ShortChannelId(scid),
+ None => NextMessageHop::NodeId(*pubkey),
+ })
+ .map(|next_hop| ControlTlvs::Forward(ForwardTlvs { next_hop, next_blinding_override: None }))
+ .chain(core::iter::once(ControlTlvs::Receive(ReceiveTlvs { path_id: None })));
- if let Some((final_ss, final_blinded_node_id)) = prev_ss_and_blinded_node_id {
- let final_payload = ReceiveTlvs { path_id: None };
- blinded_hops.push(BlindedHop {
- blinded_node_id: final_blinded_node_id,
- encrypted_payload: utils::encrypt_payload(final_payload, final_ss),
- });
- } else { debug_assert!(false) }
-
- Ok(blinded_hops)
+ utils::construct_blinded_hops(secp_ctx, pks, tlvs, session_priv)
}
// Advance the blinded onion message path by one hop, so make the second hop into the new
// introduction node.
-pub(crate) fn advance_path_by_one<NS: Deref, T: secp256k1::Signing + secp256k1::Verification>(
- path: &mut BlindedPath, node_signer: &NS, secp_ctx: &Secp256k1<T>
-) -> Result<(), ()> where NS::Target: NodeSigner {
+pub(crate) fn advance_path_by_one<NS: Deref, NL: Deref, T>(
+ path: &mut BlindedPath, node_signer: &NS, node_id_lookup: &NL, secp_ctx: &Secp256k1<T>
+) -> Result<(), ()>
+where
+ NS::Target: NodeSigner,
+ NL::Target: NodeIdLookUp,
+ T: secp256k1::Signing + secp256k1::Verification,
+{
let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &path.blinding_point, None)?;
let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
let encrypted_control_tlvs = path.blinded_hops.remove(0).encrypted_payload;
let mut s = Cursor::new(&encrypted_control_tlvs);
let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
match ChaChaPolyReadAdapter::read(&mut reader, rho) {
- Ok(ChaChaPolyReadAdapter { readable: ControlTlvs::Forward(ForwardTlvs {
- mut next_node_id, next_blinding_override,
- })}) => {
+ Ok(ChaChaPolyReadAdapter {
+ readable: ControlTlvs::Forward(ForwardTlvs { next_hop, next_blinding_override })
+ }) => {
+ let next_node_id = match next_hop {
+ NextMessageHop::NodeId(pubkey) => pubkey,
+ NextMessageHop::ShortChannelId(scid) => match node_id_lookup.next_node_id(scid) {
+ Some(pubkey) => pubkey,
+ None => return Err(()),
+ },
+ };
let mut new_blinding_point = match next_blinding_override {
Some(blinding_point) => blinding_point,
None => {
}
};
mem::swap(&mut path.blinding_point, &mut new_blinding_point);
- mem::swap(&mut path.introduction_node_id, &mut next_node_id);
+ path.introduction_node = IntroductionNode::NodeId(next_node_id);
Ok(())
},
_ => Err(())
projects / rust-lightning / blobdiff