1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! LDK sends, receives, and forwards onion messages via this [`OnionMessenger`], which lives here,
11 //! as well as various types, traits, and utilities that it uses.
13 use bitcoin::hashes::{Hash, HashEngine};
14 use bitcoin::hashes::hmac::{Hmac, HmacEngine};
15 use bitcoin::hashes::sha256::Hash as Sha256;
16 use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey};
18 use crate::blinded_path::{BlindedPath, IntroductionNode, NodeIdLookUp};
19 use crate::blinded_path::message::{advance_path_by_one, ForwardTlvs, NextHop, ReceiveTlvs};
20 use crate::blinded_path::utils;
21 use crate::events::{Event, EventHandler, EventsProvider};
22 use crate::sign::{EntropySource, NodeSigner, Recipient};
23 use crate::ln::features::{InitFeatures, NodeFeatures};
24 use crate::ln::msgs::{self, OnionMessage, OnionMessageHandler, SocketAddress};
25 use crate::ln::onion_utils;
26 use crate::routing::gossip::{NetworkGraph, NodeId, ReadOnlyNetworkGraph};
27 use super::packet::OnionMessageContents;
28 use super::packet::ParsedOnionMessageContents;
29 use super::offers::OffersMessageHandler;
30 use super::packet::{BIG_PACKET_HOP_DATA_LEN, ForwardControlTlvs, Packet, Payload, ReceiveControlTlvs, SMALL_PACKET_HOP_DATA_LEN};
31 use crate::util::logger::{Logger, WithContext};
32 use crate::util::ser::Writeable;
37 use crate::sync::Mutex;
38 use crate::prelude::*;
40 #[cfg(not(c_bindings))]
42 crate::sign::KeysManager,
43 crate::ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager},
44 crate::ln::peer_handler::IgnoringMessageHandler,
48 pub(super) const MAX_TIMER_TICKS: usize = 2;
50 /// A sender, receiver and forwarder of [`OnionMessage`]s.
52 /// # Handling Messages
54 /// `OnionMessenger` implements [`OnionMessageHandler`], making it responsible for either forwarding
55 /// messages to peers or delegating to the appropriate handler for the message type. Currently, the
56 /// available handlers are:
57 /// * [`OffersMessageHandler`], for responding to [`InvoiceRequest`]s and paying [`Bolt12Invoice`]s
58 /// * [`CustomOnionMessageHandler`], for handling user-defined message types
60 /// # Sending Messages
62 /// [`OnionMessage`]s are sent initially using [`OnionMessenger::send_onion_message`]. When handling
63 /// a message, the matched handler may return a response message which `OnionMessenger` will send
69 /// # extern crate bitcoin;
70 /// # use bitcoin::hashes::_export::_core::time::Duration;
71 /// # use bitcoin::hashes::hex::FromHex;
72 /// # use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey, self};
73 /// # use lightning::blinded_path::{BlindedPath, EmptyNodeIdLookUp};
74 /// # use lightning::sign::{EntropySource, KeysManager};
75 /// # use lightning::ln::peer_handler::IgnoringMessageHandler;
76 /// # use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath, OnionMessenger};
77 /// # use lightning::onion_message::packet::OnionMessageContents;
78 /// # use lightning::util::logger::{Logger, Record};
79 /// # use lightning::util::ser::{Writeable, Writer};
80 /// # use lightning::io;
81 /// # use std::sync::Arc;
82 /// # struct FakeLogger;
83 /// # impl Logger for FakeLogger {
84 /// # fn log(&self, record: Record) { println!("{:?}" , record); }
86 /// # struct FakeMessageRouter {}
87 /// # impl MessageRouter for FakeMessageRouter {
88 /// # fn find_path(&self, sender: PublicKey, peers: Vec<PublicKey>, destination: Destination) -> Result<OnionMessagePath, ()> {
89 /// # let secp_ctx = Secp256k1::new();
90 /// # let node_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
91 /// # let hop_node_id1 = PublicKey::from_secret_key(&secp_ctx, &node_secret);
92 /// # let hop_node_id2 = hop_node_id1;
93 /// # Ok(OnionMessagePath {
94 /// # intermediate_nodes: vec![hop_node_id1, hop_node_id2],
96 /// # first_node_addresses: None,
99 /// # fn create_blinded_paths<T: secp256k1::Signing + secp256k1::Verification>(
100 /// # &self, _recipient: PublicKey, _peers: Vec<PublicKey>, _secp_ctx: &Secp256k1<T>
101 /// # ) -> Result<Vec<BlindedPath>, ()> {
105 /// # let seed = [42u8; 32];
106 /// # let time = Duration::from_secs(123456);
107 /// # let keys_manager = KeysManager::new(&seed, time.as_secs(), time.subsec_nanos());
108 /// # let logger = Arc::new(FakeLogger {});
109 /// # let node_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
110 /// # let secp_ctx = Secp256k1::new();
111 /// # let hop_node_id1 = PublicKey::from_secret_key(&secp_ctx, &node_secret);
112 /// # let (hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1);
113 /// # let destination_node_id = hop_node_id1;
114 /// # let node_id_lookup = EmptyNodeIdLookUp {};
115 /// # let message_router = Arc::new(FakeMessageRouter {});
116 /// # let custom_message_handler = IgnoringMessageHandler {};
117 /// # let offers_message_handler = IgnoringMessageHandler {};
118 /// // Create the onion messenger. This must use the same `keys_manager` as is passed to your
119 /// // ChannelManager.
120 /// let onion_messenger = OnionMessenger::new(
121 /// &keys_manager, &keys_manager, logger, &node_id_lookup, message_router,
122 /// &offers_message_handler, &custom_message_handler
125 /// # #[derive(Debug)]
126 /// # struct YourCustomMessage {}
127 /// impl Writeable for YourCustomMessage {
128 /// fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
130 /// // Write your custom onion message to `w`
133 /// impl OnionMessageContents for YourCustomMessage {
134 /// fn tlv_type(&self) -> u64 {
135 /// # let your_custom_message_type = 42;
136 /// your_custom_message_type
139 /// // Send a custom onion message to a node id.
140 /// let destination = Destination::Node(destination_node_id);
141 /// let reply_path = None;
142 /// # let message = YourCustomMessage {};
143 /// onion_messenger.send_onion_message(message, destination, reply_path);
145 /// // Create a blinded path to yourself, for someone to send an onion message to.
146 /// # let your_node_id = hop_node_id1;
147 /// let hops = [hop_node_id3, hop_node_id4, your_node_id];
148 /// let blinded_path = BlindedPath::new_for_message(&hops, &keys_manager, &secp_ctx).unwrap();
150 /// // Send a custom onion message to a blinded path.
151 /// let destination = Destination::BlindedPath(blinded_path);
152 /// let reply_path = None;
153 /// # let message = YourCustomMessage {};
154 /// onion_messenger.send_onion_message(message, destination, reply_path);
157 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
158 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
159 pub struct OnionMessenger<ES: Deref, NS: Deref, L: Deref, NL: Deref, MR: Deref, OMH: Deref, CMH: Deref>
161 ES::Target: EntropySource,
162 NS::Target: NodeSigner,
164 NL::Target: NodeIdLookUp,
165 MR::Target: MessageRouter,
166 OMH::Target: OffersMessageHandler,
167 CMH::Target: CustomOnionMessageHandler,
172 message_recipients: Mutex<HashMap<PublicKey, OnionMessageRecipient>>,
173 secp_ctx: Secp256k1<secp256k1::All>,
178 intercept_messages_for_offline_peers: bool,
179 pending_events: Mutex<Vec<Event>>,
182 /// [`OnionMessage`]s buffered to be sent.
183 enum OnionMessageRecipient {
184 /// Messages for a node connected as a peer.
185 ConnectedPeer(VecDeque<OnionMessage>),
187 /// Messages for a node that is not yet connected, which are dropped after [`MAX_TIMER_TICKS`]
188 /// and tracked here.
189 PendingConnection(VecDeque<OnionMessage>, Option<Vec<SocketAddress>>, usize),
192 impl OnionMessageRecipient {
193 fn pending_connection(addresses: Vec<SocketAddress>) -> Self {
194 Self::PendingConnection(VecDeque::new(), Some(addresses), 0)
197 fn pending_messages(&self) -> &VecDeque<OnionMessage> {
199 OnionMessageRecipient::ConnectedPeer(pending_messages) => pending_messages,
200 OnionMessageRecipient::PendingConnection(pending_messages, _, _) => pending_messages,
204 fn enqueue_message(&mut self, message: OnionMessage) {
205 let pending_messages = match self {
206 OnionMessageRecipient::ConnectedPeer(pending_messages) => pending_messages,
207 OnionMessageRecipient::PendingConnection(pending_messages, _, _) => pending_messages,
210 pending_messages.push_back(message);
213 fn dequeue_message(&mut self) -> Option<OnionMessage> {
214 let pending_messages = match self {
215 OnionMessageRecipient::ConnectedPeer(pending_messages) => pending_messages,
216 OnionMessageRecipient::PendingConnection(pending_messages, _, _) => {
217 debug_assert!(false);
222 pending_messages.pop_front()
226 fn release_pending_messages(&mut self) -> VecDeque<OnionMessage> {
227 let pending_messages = match self {
228 OnionMessageRecipient::ConnectedPeer(pending_messages) => pending_messages,
229 OnionMessageRecipient::PendingConnection(pending_messages, _, _) => pending_messages,
232 core::mem::take(pending_messages)
235 fn mark_connected(&mut self) {
236 if let OnionMessageRecipient::PendingConnection(pending_messages, _, _) = self {
237 let mut new_pending_messages = VecDeque::new();
238 core::mem::swap(pending_messages, &mut new_pending_messages);
239 *self = OnionMessageRecipient::ConnectedPeer(new_pending_messages);
243 fn is_connected(&self) -> bool {
245 OnionMessageRecipient::ConnectedPeer(..) => true,
246 OnionMessageRecipient::PendingConnection(..) => false,
251 /// An [`OnionMessage`] for [`OnionMessenger`] to send.
253 /// These are obtained when released from [`OnionMessenger`]'s handlers after which they are
254 /// enqueued for sending.
255 #[cfg(not(c_bindings))]
256 pub struct PendingOnionMessage<T: OnionMessageContents> {
257 /// The message contents to send in an [`OnionMessage`].
260 /// The destination of the message.
261 pub destination: Destination,
263 /// A reply path to include in the [`OnionMessage`] for a response.
264 pub reply_path: Option<BlindedPath>,
268 /// An [`OnionMessage`] for [`OnionMessenger`] to send.
270 /// These are obtained when released from [`OnionMessenger`]'s handlers after which they are
271 /// enqueued for sending.
272 pub type PendingOnionMessage<T> = (T, Destination, Option<BlindedPath>);
274 pub(crate) fn new_pending_onion_message<T: OnionMessageContents>(
275 contents: T, destination: Destination, reply_path: Option<BlindedPath>
276 ) -> PendingOnionMessage<T> {
277 #[cfg(not(c_bindings))]
278 return PendingOnionMessage { contents, destination, reply_path };
280 return (contents, destination, reply_path);
283 /// A trait defining behavior for routing an [`OnionMessage`].
284 pub trait MessageRouter {
285 /// Returns a route for sending an [`OnionMessage`] to the given [`Destination`].
287 &self, sender: PublicKey, peers: Vec<PublicKey>, destination: Destination
288 ) -> Result<OnionMessagePath, ()>;
290 /// Creates [`BlindedPath`]s to the `recipient` node. The nodes in `peers` are assumed to be
291 /// direct peers with the `recipient`.
292 fn create_blinded_paths<
293 T: secp256k1::Signing + secp256k1::Verification
295 &self, recipient: PublicKey, peers: Vec<PublicKey>, secp_ctx: &Secp256k1<T>,
296 ) -> Result<Vec<BlindedPath>, ()>;
299 /// A [`MessageRouter`] that can only route to a directly connected [`Destination`].
300 pub struct DefaultMessageRouter<G: Deref<Target=NetworkGraph<L>>, L: Deref, ES: Deref>
303 ES::Target: EntropySource,
309 impl<G: Deref<Target=NetworkGraph<L>>, L: Deref, ES: Deref> DefaultMessageRouter<G, L, ES>
312 ES::Target: EntropySource,
314 /// Creates a [`DefaultMessageRouter`] using the given [`NetworkGraph`].
315 pub fn new(network_graph: G, entropy_source: ES) -> Self {
316 Self { network_graph, entropy_source }
320 impl<G: Deref<Target=NetworkGraph<L>>, L: Deref, ES: Deref> MessageRouter for DefaultMessageRouter<G, L, ES>
323 ES::Target: EntropySource,
326 &self, sender: PublicKey, peers: Vec<PublicKey>, mut destination: Destination
327 ) -> Result<OnionMessagePath, ()> {
328 let network_graph = self.network_graph.deref().read_only();
329 destination.resolve(&network_graph);
331 let first_node = match destination.first_node() {
332 Some(first_node) => first_node,
333 None => return Err(()),
336 if peers.contains(&first_node) || sender == first_node {
337 Ok(OnionMessagePath {
338 intermediate_nodes: vec![], destination, first_node_addresses: None
341 let node_announcement = network_graph
342 .node(&NodeId::from_pubkey(&first_node))
343 .and_then(|node_info| node_info.announcement_info.as_ref())
344 .and_then(|announcement_info| announcement_info.announcement_message.as_ref())
345 .map(|node_announcement| &node_announcement.contents);
347 match node_announcement {
348 Some(node_announcement) if node_announcement.features.supports_onion_messages() => {
349 let first_node_addresses = Some(node_announcement.addresses.clone());
350 Ok(OnionMessagePath {
351 intermediate_nodes: vec![], destination, first_node_addresses
359 fn create_blinded_paths<
360 T: secp256k1::Signing + secp256k1::Verification
362 &self, recipient: PublicKey, peers: Vec<PublicKey>, secp_ctx: &Secp256k1<T>,
363 ) -> Result<Vec<BlindedPath>, ()> {
364 // Limit the number of blinded paths that are computed.
365 const MAX_PATHS: usize = 3;
367 // Ensure peers have at least three channels so that it is more difficult to infer the
368 // recipient's node_id.
369 const MIN_PEER_CHANNELS: usize = 3;
371 let network_graph = self.network_graph.deref().read_only();
372 let is_recipient_announced =
373 network_graph.nodes().contains_key(&NodeId::from_pubkey(&recipient));
375 let mut peer_info = peers.iter()
376 // Limit to peers with announced channels
379 .node(&NodeId::from_pubkey(pubkey))
380 .filter(|info| info.channels.len() >= MIN_PEER_CHANNELS)
381 .map(|info| (*pubkey, info.is_tor_only(), info.channels.len()))
383 // Exclude Tor-only nodes when the recipient is announced.
384 .filter(|(_, is_tor_only, _)| !(*is_tor_only && is_recipient_announced))
385 .collect::<Vec<_>>();
387 // Prefer using non-Tor nodes with the most channels as the introduction node.
388 peer_info.sort_unstable_by(|(_, a_tor_only, a_channels), (_, b_tor_only, b_channels)| {
389 a_tor_only.cmp(b_tor_only).then(a_channels.cmp(b_channels).reverse())
392 let paths = peer_info.into_iter()
393 .map(|(pubkey, _, _)| vec![pubkey, recipient])
394 .map(|node_pks| BlindedPath::new_for_message(&node_pks, &*self.entropy_source, secp_ctx))
396 .collect::<Result<Vec<_>, _>>();
399 Ok(paths) if !paths.is_empty() => Ok(paths),
401 if is_recipient_announced {
402 BlindedPath::one_hop_for_message(recipient, &*self.entropy_source, secp_ctx)
403 .map(|path| vec![path])
412 /// A path for sending an [`OnionMessage`].
414 pub struct OnionMessagePath {
415 /// Nodes on the path between the sender and the destination.
416 pub intermediate_nodes: Vec<PublicKey>,
418 /// The recipient of the message.
419 pub destination: Destination,
421 /// Addresses that may be used to connect to [`OnionMessagePath::first_node`].
423 /// Only needs to be set if a connection to the node is required. [`OnionMessenger`] may use
424 /// this to initiate such a connection.
425 pub first_node_addresses: Option<Vec<SocketAddress>>,
428 impl OnionMessagePath {
429 /// Returns the first node in the path.
430 pub fn first_node(&self) -> Option<PublicKey> {
431 self.intermediate_nodes
434 .or_else(|| self.destination.first_node())
438 /// The destination of an onion message.
439 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
440 pub enum Destination {
441 /// We're sending this onion message to a node.
443 /// We're sending this onion message to a blinded path.
444 BlindedPath(BlindedPath),
448 /// Attempts to resolve the [`IntroductionNode::DirectedShortChannelId`] of a
449 /// [`Destination::BlindedPath`] to a [`IntroductionNode::NodeId`], if applicable, using the
450 /// provided [`ReadOnlyNetworkGraph`].
451 pub fn resolve(&mut self, network_graph: &ReadOnlyNetworkGraph) {
452 if let Destination::BlindedPath(path) = self {
453 if let IntroductionNode::DirectedShortChannelId(..) = path.introduction_node {
454 if let Some(pubkey) = path
455 .public_introduction_node_id(network_graph)
456 .and_then(|node_id| node_id.as_pubkey().ok())
458 path.introduction_node = IntroductionNode::NodeId(pubkey);
464 pub(super) fn num_hops(&self) -> usize {
466 Destination::Node(_) => 1,
467 Destination::BlindedPath(BlindedPath { blinded_hops, .. }) => blinded_hops.len(),
471 fn first_node(&self) -> Option<PublicKey> {
473 Destination::Node(node_id) => Some(*node_id),
474 Destination::BlindedPath(BlindedPath { introduction_node, .. }) => {
475 match introduction_node {
476 IntroductionNode::NodeId(pubkey) => Some(*pubkey),
477 IntroductionNode::DirectedShortChannelId(..) => None,
484 /// Result of successfully [sending an onion message].
486 /// [sending an onion message]: OnionMessenger::send_onion_message
487 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
488 pub enum SendSuccess {
489 /// The message was buffered and will be sent once it is processed by
490 /// [`OnionMessageHandler::next_onion_message_for_peer`].
492 /// The message was buffered and will be sent once the node is connected as a peer and it is
493 /// processed by [`OnionMessageHandler::next_onion_message_for_peer`].
494 BufferedAwaitingConnection(PublicKey),
497 /// Errors that may occur when [sending an onion message].
499 /// [sending an onion message]: OnionMessenger::send_onion_message
500 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
502 /// Errored computing onion message packet keys.
503 Secp256k1(secp256k1::Error),
504 /// Because implementations such as Eclair will drop onion messages where the message packet
505 /// exceeds 32834 bytes, we refuse to send messages where the packet exceeds this size.
507 /// The provided [`Destination`] was an invalid [`BlindedPath`] due to not having any blinded
510 /// The first hop is not a peer and doesn't have a known [`SocketAddress`].
511 InvalidFirstHop(PublicKey),
512 /// A path from the sender to the destination could not be found by the [`MessageRouter`].
514 /// Onion message contents must have a TLV type >= 64.
516 /// Our next-hop peer's buffer was full or our total outbound buffer was full.
518 /// Failed to retrieve our node id from the provided [`NodeSigner`].
520 /// [`NodeSigner`]: crate::sign::NodeSigner
522 /// The provided [`Destination`] has a blinded path with an unresolved introduction node. An
523 /// attempt to resolve it in the [`MessageRouter`] when finding an [`OnionMessagePath`] likely
525 UnresolvedIntroductionNode,
526 /// We attempted to send to a blinded path where we are the introduction node, and failed to
527 /// advance the blinded path to make the second hop the new introduction node. Either
528 /// [`NodeSigner::ecdh`] failed, we failed to tweak the current blinding point to get the
529 /// new blinding point, or we were attempting to send to ourselves.
530 BlindedPathAdvanceFailed,
533 /// Handler for custom onion messages. If you are using [`SimpleArcOnionMessenger`],
534 /// [`SimpleRefOnionMessenger`], or prefer to ignore inbound custom onion messages,
535 /// [`IgnoringMessageHandler`] must be provided to [`OnionMessenger::new`]. Otherwise, a custom
536 /// implementation of this trait must be provided, with [`CustomMessage`] specifying the supported
539 /// See [`OnionMessenger`] for example usage.
541 /// [`IgnoringMessageHandler`]: crate::ln::peer_handler::IgnoringMessageHandler
542 /// [`CustomMessage`]: Self::CustomMessage
543 pub trait CustomOnionMessageHandler {
544 /// The message known to the handler. To support multiple message types, you may want to make this
545 /// an enum with a variant for each supported message.
546 type CustomMessage: OnionMessageContents;
548 /// Called with the custom message that was received, returning a response to send, if any.
550 /// The returned [`Self::CustomMessage`], if any, is enqueued to be sent by [`OnionMessenger`].
551 fn handle_custom_message(&self, msg: Self::CustomMessage) -> Option<Self::CustomMessage>;
553 /// Read a custom message of type `message_type` from `buffer`, returning `Ok(None)` if the
554 /// message type is unknown.
555 fn read_custom_message<R: io::Read>(&self, message_type: u64, buffer: &mut R) -> Result<Option<Self::CustomMessage>, msgs::DecodeError>;
557 /// Releases any [`Self::CustomMessage`]s that need to be sent.
559 /// Typically, this is used for messages initiating a message flow rather than in response to
560 /// another message. The latter should use the return value of [`Self::handle_custom_message`].
561 #[cfg(not(c_bindings))]
562 fn release_pending_custom_messages(&self) -> Vec<PendingOnionMessage<Self::CustomMessage>>;
564 /// Releases any [`Self::CustomMessage`]s that need to be sent.
566 /// Typically, this is used for messages initiating a message flow rather than in response to
567 /// another message. The latter should use the return value of [`Self::handle_custom_message`].
569 fn release_pending_custom_messages(&self) -> Vec<(Self::CustomMessage, Destination, Option<BlindedPath>)>;
572 /// A processed incoming onion message, containing either a Forward (another onion message)
573 /// or a Receive payload with decrypted contents.
575 pub enum PeeledOnion<T: OnionMessageContents> {
576 /// Forwarded onion, with the next node id and a new onion
577 Forward(NextHop, OnionMessage),
578 /// Received onion message, with decrypted contents, path_id, and reply path
579 Receive(ParsedOnionMessageContents<T>, Option<[u8; 32]>, Option<BlindedPath>)
583 /// Creates an [`OnionMessage`] with the given `contents` for sending to the destination of
584 /// `path`, first calling [`Destination::resolve`] on `path.destination` with the given
585 /// [`ReadOnlyNetworkGraph`].
587 /// Returns the node id of the peer to send the message to, the message itself, and any addresses
588 /// needed to connect to the first node.
589 pub fn create_onion_message_resolving_destination<
590 ES: Deref, NS: Deref, NL: Deref, T: OnionMessageContents
592 entropy_source: &ES, node_signer: &NS, node_id_lookup: &NL,
593 network_graph: &ReadOnlyNetworkGraph, secp_ctx: &Secp256k1<secp256k1::All>,
594 mut path: OnionMessagePath, contents: T, reply_path: Option<BlindedPath>,
595 ) -> Result<(PublicKey, OnionMessage, Option<Vec<SocketAddress>>), SendError>
597 ES::Target: EntropySource,
598 NS::Target: NodeSigner,
599 NL::Target: NodeIdLookUp,
601 path.destination.resolve(network_graph);
602 create_onion_message(
603 entropy_source, node_signer, node_id_lookup, secp_ctx, path, contents, reply_path,
607 /// Creates an [`OnionMessage`] with the given `contents` for sending to the destination of
610 /// Returns the node id of the peer to send the message to, the message itself, and any addresses
611 /// needed to connect to the first node.
613 /// Returns [`SendError::UnresolvedIntroductionNode`] if:
614 /// - `destination` contains a blinded path with an [`IntroductionNode::DirectedShortChannelId`],
615 /// - unless it can be resolved by [`NodeIdLookUp::next_node_id`].
616 /// Use [`create_onion_message_resolving_destination`] instead to resolve the introduction node
617 /// first with a [`ReadOnlyNetworkGraph`].
618 pub fn create_onion_message<ES: Deref, NS: Deref, NL: Deref, T: OnionMessageContents>(
619 entropy_source: &ES, node_signer: &NS, node_id_lookup: &NL,
620 secp_ctx: &Secp256k1<secp256k1::All>, path: OnionMessagePath, contents: T,
621 reply_path: Option<BlindedPath>,
622 ) -> Result<(PublicKey, OnionMessage, Option<Vec<SocketAddress>>), SendError>
624 ES::Target: EntropySource,
625 NS::Target: NodeSigner,
626 NL::Target: NodeIdLookUp,
628 let OnionMessagePath { intermediate_nodes, mut destination, first_node_addresses } = path;
629 if let Destination::BlindedPath(BlindedPath { ref blinded_hops, .. }) = destination {
630 if blinded_hops.is_empty() {
631 return Err(SendError::TooFewBlindedHops);
635 if contents.tlv_type() < 64 { return Err(SendError::InvalidMessage) }
637 // If we are sending straight to a blinded path and we are the introduction node, we need to
638 // advance the blinded path by 1 hop so the second hop is the new introduction node.
639 if intermediate_nodes.len() == 0 {
640 if let Destination::BlindedPath(ref mut blinded_path) = destination {
641 let our_node_id = node_signer.get_node_id(Recipient::Node)
642 .map_err(|()| SendError::GetNodeIdFailed)?;
643 let introduction_node_id = match blinded_path.introduction_node {
644 IntroductionNode::NodeId(pubkey) => pubkey,
645 IntroductionNode::DirectedShortChannelId(direction, scid) => {
646 match node_id_lookup.next_node_id(scid) {
647 Some(next_node_id) => *direction.select_pubkey(&our_node_id, &next_node_id),
648 None => return Err(SendError::UnresolvedIntroductionNode),
652 if introduction_node_id == our_node_id {
653 advance_path_by_one(blinded_path, node_signer, node_id_lookup, &secp_ctx)
654 .map_err(|()| SendError::BlindedPathAdvanceFailed)?;
659 let blinding_secret_bytes = entropy_source.get_secure_random_bytes();
660 let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
661 let (first_node_id, blinding_point) = if let Some(first_node_id) = intermediate_nodes.first() {
662 (*first_node_id, PublicKey::from_secret_key(&secp_ctx, &blinding_secret))
665 Destination::Node(pk) => (*pk, PublicKey::from_secret_key(&secp_ctx, &blinding_secret)),
666 Destination::BlindedPath(BlindedPath { introduction_node, blinding_point, .. }) => {
667 match introduction_node {
668 IntroductionNode::NodeId(pubkey) => (*pubkey, *blinding_point),
669 IntroductionNode::DirectedShortChannelId(..) => {
670 return Err(SendError::UnresolvedIntroductionNode);
676 let (packet_payloads, packet_keys) = packet_payloads_and_keys(
677 &secp_ctx, &intermediate_nodes, destination, contents, reply_path, &blinding_secret
680 let prng_seed = entropy_source.get_secure_random_bytes();
681 let onion_routing_packet = construct_onion_message_packet(
682 packet_payloads, packet_keys, prng_seed).map_err(|()| SendError::TooBigPacket)?;
684 let message = OnionMessage { blinding_point, onion_routing_packet };
685 Ok((first_node_id, message, first_node_addresses))
688 /// Decode one layer of an incoming [`OnionMessage`].
690 /// Returns either the next layer of the onion for forwarding or the decrypted content for the
692 pub fn peel_onion_message<NS: Deref, L: Deref, CMH: Deref>(
693 msg: &OnionMessage, secp_ctx: &Secp256k1<secp256k1::All>, node_signer: NS, logger: L,
695 ) -> Result<PeeledOnion<<<CMH>::Target as CustomOnionMessageHandler>::CustomMessage>, ()>
697 NS::Target: NodeSigner,
699 CMH::Target: CustomOnionMessageHandler,
701 let control_tlvs_ss = match node_signer.ecdh(Recipient::Node, &msg.blinding_point, None) {
704 log_error!(logger, "Failed to retrieve node secret: {:?}", e);
708 let onion_decode_ss = {
709 let blinding_factor = {
710 let mut hmac = HmacEngine::<Sha256>::new(b"blinded_node_id");
711 hmac.input(control_tlvs_ss.as_ref());
712 Hmac::from_engine(hmac).to_byte_array()
714 match node_signer.ecdh(Recipient::Node, &msg.onion_routing_packet.public_key,
715 Some(&Scalar::from_be_bytes(blinding_factor).unwrap()))
717 Ok(ss) => ss.secret_bytes(),
719 log_trace!(logger, "Failed to compute onion packet shared secret");
724 match onion_utils::decode_next_untagged_hop(
725 onion_decode_ss, &msg.onion_routing_packet.hop_data[..], msg.onion_routing_packet.hmac,
726 (control_tlvs_ss, custom_handler.deref(), logger.deref())
728 Ok((Payload::Receive::<ParsedOnionMessageContents<<<CMH as Deref>::Target as CustomOnionMessageHandler>::CustomMessage>> {
729 message, control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path,
731 Ok(PeeledOnion::Receive(message, path_id, reply_path))
733 Ok((Payload::Forward(ForwardControlTlvs::Unblinded(ForwardTlvs {
734 next_hop, next_blinding_override
735 })), Some((next_hop_hmac, new_packet_bytes)))) => {
736 // TODO: we need to check whether `next_hop` is our node, in which case this is a dummy
737 // blinded hop and this onion message is destined for us. In this situation, we should keep
738 // unwrapping the onion layers to get to the final payload. Since we don't have the option
739 // of creating blinded paths with dummy hops currently, we should be ok to not handle this
741 let new_pubkey = match onion_utils::next_hop_pubkey(&secp_ctx, msg.onion_routing_packet.public_key, &onion_decode_ss) {
744 log_trace!(logger, "Failed to compute next hop packet pubkey: {}", e);
748 let outgoing_packet = Packet {
750 public_key: new_pubkey,
751 hop_data: new_packet_bytes,
754 let onion_message = OnionMessage {
755 blinding_point: match next_blinding_override {
756 Some(blinding_point) => blinding_point,
758 match onion_utils::next_hop_pubkey(
759 &secp_ctx, msg.blinding_point, control_tlvs_ss.as_ref()
763 log_trace!(logger, "Failed to compute next blinding point: {}", e);
769 onion_routing_packet: outgoing_packet,
772 Ok(PeeledOnion::Forward(next_hop, onion_message))
775 log_trace!(logger, "Errored decoding onion message packet: {:?}", e);
779 log_trace!(logger, "Received bogus onion message packet, either the sender encoded a final hop as a forwarding hop or vice versa");
785 impl<ES: Deref, NS: Deref, L: Deref, NL: Deref, MR: Deref, OMH: Deref, CMH: Deref>
786 OnionMessenger<ES, NS, L, NL, MR, OMH, CMH>
788 ES::Target: EntropySource,
789 NS::Target: NodeSigner,
791 NL::Target: NodeIdLookUp,
792 MR::Target: MessageRouter,
793 OMH::Target: OffersMessageHandler,
794 CMH::Target: CustomOnionMessageHandler,
796 /// Constructs a new `OnionMessenger` to send, forward, and delegate received onion messages to
797 /// their respective handlers.
799 entropy_source: ES, node_signer: NS, logger: L, node_id_lookup: NL, message_router: MR,
800 offers_handler: OMH, custom_handler: CMH
803 entropy_source, node_signer, logger, node_id_lookup, message_router,
804 offers_handler, custom_handler, false
809 pub fn new_with_offline_peer_interception(
810 entropy_source: ES, node_signer: NS, logger: L, node_id_lookup: NL,
811 message_router: MR, offers_handler: OMH, custom_handler: CMH
814 entropy_source, node_signer, logger, node_id_lookup, message_router,
815 offers_handler, custom_handler, true
820 entropy_source: ES, node_signer: NS, logger: L, node_id_lookup: NL,
821 message_router: MR, offers_handler: OMH, custom_handler: CMH,
822 intercept_messages_for_offline_peers: bool
824 let mut secp_ctx = Secp256k1::new();
825 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
829 message_recipients: Mutex::new(new_hash_map()),
836 intercept_messages_for_offline_peers,
837 pending_events: Mutex::new(Vec::new()),
842 pub(crate) fn set_offers_handler(&mut self, offers_handler: OMH) {
843 self.offers_handler = offers_handler;
846 /// Sends an [`OnionMessage`] with the given `contents` to `destination`.
848 /// See [`OnionMessenger`] for example usage.
849 pub fn send_onion_message<T: OnionMessageContents>(
850 &self, contents: T, destination: Destination, reply_path: Option<BlindedPath>
851 ) -> Result<SendSuccess, SendError> {
852 self.find_path_and_enqueue_onion_message(
853 contents, destination, reply_path, format_args!("")
857 fn find_path_and_enqueue_onion_message<T: OnionMessageContents>(
858 &self, contents: T, destination: Destination, reply_path: Option<BlindedPath>,
859 log_suffix: fmt::Arguments
860 ) -> Result<SendSuccess, SendError> {
861 let mut logger = WithContext::from(&self.logger, None, None);
862 let result = self.find_path(destination)
864 let first_hop = path.intermediate_nodes.get(0).map(|p| *p);
865 logger = WithContext::from(&self.logger, first_hop, None);
866 self.enqueue_onion_message(path, contents, reply_path, log_suffix)
869 match result.as_ref() {
870 Err(SendError::GetNodeIdFailed) => {
871 log_warn!(logger, "Unable to retrieve node id {}", log_suffix);
873 Err(SendError::PathNotFound) => {
874 log_trace!(logger, "Failed to find path {}", log_suffix);
877 log_trace!(logger, "Failed sending onion message {}: {:?}", log_suffix, e);
879 Ok(SendSuccess::Buffered) => {
880 log_trace!(logger, "Buffered onion message {}", log_suffix);
882 Ok(SendSuccess::BufferedAwaitingConnection(node_id)) => {
885 "Buffered onion message waiting on peer connection {}: {}",
894 fn find_path(&self, destination: Destination) -> Result<OnionMessagePath, SendError> {
895 let sender = self.node_signer
896 .get_node_id(Recipient::Node)
897 .map_err(|_| SendError::GetNodeIdFailed)?;
899 let peers = self.message_recipients.lock().unwrap()
901 .filter(|(_, recipient)| matches!(recipient, OnionMessageRecipient::ConnectedPeer(_)))
902 .map(|(node_id, _)| *node_id)
906 .find_path(sender, peers, destination)
907 .map_err(|_| SendError::PathNotFound)
910 fn enqueue_onion_message<T: OnionMessageContents>(
911 &self, path: OnionMessagePath, contents: T, reply_path: Option<BlindedPath>,
912 log_suffix: fmt::Arguments
913 ) -> Result<SendSuccess, SendError> {
914 log_trace!(self.logger, "Constructing onion message {}: {:?}", log_suffix, contents);
916 let (first_node_id, onion_message, addresses) = create_onion_message(
917 &self.entropy_source, &self.node_signer, &self.node_id_lookup, &self.secp_ctx, path,
918 contents, reply_path,
921 let mut message_recipients = self.message_recipients.lock().unwrap();
922 if outbound_buffer_full(&first_node_id, &message_recipients) {
923 return Err(SendError::BufferFull);
926 match message_recipients.entry(first_node_id) {
927 hash_map::Entry::Vacant(e) => match addresses {
928 None => Err(SendError::InvalidFirstHop(first_node_id)),
930 e.insert(OnionMessageRecipient::pending_connection(addresses))
931 .enqueue_message(onion_message);
932 Ok(SendSuccess::BufferedAwaitingConnection(first_node_id))
935 hash_map::Entry::Occupied(mut e) => {
936 e.get_mut().enqueue_message(onion_message);
937 if e.get().is_connected() {
938 Ok(SendSuccess::Buffered)
940 Ok(SendSuccess::BufferedAwaitingConnection(first_node_id))
946 /// Forwards an [`OnionMessage`] to `peer_node_id`. Useful if we initialized
947 /// the [`OnionMessenger`] with [`Self::new_with_offline_peer_interception`]
948 /// and want to forward a previously intercepted onion message to a peer that
949 /// has just come online.
950 pub fn forward_onion_message(
951 &self, message: OnionMessage, peer_node_id: &PublicKey
952 ) -> Result<(), SendError> {
953 let mut message_recipients = self.message_recipients.lock().unwrap();
954 if outbound_buffer_full(&peer_node_id, &message_recipients) {
955 return Err(SendError::BufferFull);
958 match message_recipients.entry(*peer_node_id) {
959 hash_map::Entry::Occupied(mut e) if e.get().is_connected() => {
960 e.get_mut().enqueue_message(message);
963 _ => Err(SendError::InvalidFirstHop(*peer_node_id))
967 #[cfg(any(test, feature = "_test_utils"))]
968 pub fn send_onion_message_using_path<T: OnionMessageContents>(
969 &self, path: OnionMessagePath, contents: T, reply_path: Option<BlindedPath>
970 ) -> Result<SendSuccess, SendError> {
971 self.enqueue_onion_message(path, contents, reply_path, format_args!(""))
974 pub(crate) fn peel_onion_message(
975 &self, msg: &OnionMessage
976 ) -> Result<PeeledOnion<<<CMH>::Target as CustomOnionMessageHandler>::CustomMessage>, ()> {
978 msg, &self.secp_ctx, &*self.node_signer, &*self.logger, &*self.custom_handler
982 fn handle_onion_message_response<T: OnionMessageContents>(
983 &self, response: Option<T>, reply_path: Option<BlindedPath>, log_suffix: fmt::Arguments
985 if let Some(response) = response {
987 Some(reply_path) => {
988 let _ = self.find_path_and_enqueue_onion_message(
989 response, Destination::BlindedPath(reply_path), None, log_suffix
993 log_trace!(self.logger, "Missing reply path {}", log_suffix);
1000 pub(super) fn release_pending_msgs(&self) -> HashMap<PublicKey, VecDeque<OnionMessage>> {
1001 let mut message_recipients = self.message_recipients.lock().unwrap();
1002 let mut msgs = new_hash_map();
1003 // We don't want to disconnect the peers by removing them entirely from the original map, so we
1004 // release the pending message buffers individually.
1005 for (node_id, recipient) in &mut *message_recipients {
1006 msgs.insert(*node_id, recipient.release_pending_messages());
1012 fn outbound_buffer_full(peer_node_id: &PublicKey, buffer: &HashMap<PublicKey, OnionMessageRecipient>) -> bool {
1013 const MAX_TOTAL_BUFFER_SIZE: usize = (1 << 20) * 128;
1014 const MAX_PER_PEER_BUFFER_SIZE: usize = (1 << 10) * 256;
1015 let mut total_buffered_bytes = 0;
1016 let mut peer_buffered_bytes = 0;
1017 for (pk, peer_buf) in buffer {
1018 for om in peer_buf.pending_messages() {
1019 let om_len = om.serialized_length();
1020 if pk == peer_node_id {
1021 peer_buffered_bytes += om_len;
1023 total_buffered_bytes += om_len;
1025 if total_buffered_bytes >= MAX_TOTAL_BUFFER_SIZE ||
1026 peer_buffered_bytes >= MAX_PER_PEER_BUFFER_SIZE
1035 impl<ES: Deref, NS: Deref, L: Deref, NL: Deref, MR: Deref, OMH: Deref, CMH: Deref> EventsProvider
1036 for OnionMessenger<ES, NS, L, NL, MR, OMH, CMH>
1038 ES::Target: EntropySource,
1039 NS::Target: NodeSigner,
1041 NL::Target: NodeIdLookUp,
1042 MR::Target: MessageRouter,
1043 OMH::Target: OffersMessageHandler,
1044 CMH::Target: CustomOnionMessageHandler,
1046 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {
1047 for (node_id, recipient) in self.message_recipients.lock().unwrap().iter_mut() {
1048 if let OnionMessageRecipient::PendingConnection(_, addresses, _) = recipient {
1049 if let Some(addresses) = addresses.take() {
1050 handler.handle_event(Event::ConnectionNeeded { node_id: *node_id, addresses });
1054 let mut events = Vec::new();
1055 core::mem::swap(&mut *self.pending_events.lock().unwrap(), &mut events);
1057 handler.handle_event(ev);
1062 impl<ES: Deref, NS: Deref, L: Deref, NL: Deref, MR: Deref, OMH: Deref, CMH: Deref> OnionMessageHandler
1063 for OnionMessenger<ES, NS, L, NL, MR, OMH, CMH>
1065 ES::Target: EntropySource,
1066 NS::Target: NodeSigner,
1068 NL::Target: NodeIdLookUp,
1069 MR::Target: MessageRouter,
1070 OMH::Target: OffersMessageHandler,
1071 CMH::Target: CustomOnionMessageHandler,
1073 fn handle_onion_message(&self, peer_node_id: &PublicKey, msg: &OnionMessage) {
1074 let logger = WithContext::from(&self.logger, Some(*peer_node_id), None);
1075 match self.peel_onion_message(msg) {
1076 Ok(PeeledOnion::Receive(message, path_id, reply_path)) => {
1079 "Received an onion message with path_id {:02x?} and {} reply_path: {:?}",
1080 path_id, if reply_path.is_some() { "a" } else { "no" }, message);
1083 ParsedOnionMessageContents::Offers(msg) => {
1084 let response = self.offers_handler.handle_message(msg);
1085 self.handle_onion_message_response(
1086 response, reply_path, format_args!(
1087 "when responding to Offers onion message with path_id {:02x?}",
1092 ParsedOnionMessageContents::Custom(msg) => {
1093 let response = self.custom_handler.handle_custom_message(msg);
1094 self.handle_onion_message_response(
1095 response, reply_path, format_args!(
1096 "when responding to Custom onion message with path_id {:02x?}",
1103 Ok(PeeledOnion::Forward(next_hop, onion_message)) => {
1104 let next_node_id = match next_hop {
1105 NextHop::NodeId(pubkey) => pubkey,
1106 NextHop::ShortChannelId(scid) => match self.node_id_lookup.next_node_id(scid) {
1107 Some(pubkey) => pubkey,
1109 log_trace!(self.logger, "Dropping forwarded onion messager: unable to resolve next hop using SCID {}", scid);
1115 let mut message_recipients = self.message_recipients.lock().unwrap();
1116 if outbound_buffer_full(&next_node_id, &message_recipients) {
1119 "Dropping forwarded onion message to peer {}: outbound buffer full",
1126 .entry(next_node_id)
1127 .or_insert_with(|| OnionMessageRecipient::ConnectedPeer(VecDeque::new()));
1129 match message_recipients.entry(next_node_id) {
1130 hash_map::Entry::Occupied(mut e) if matches!(
1131 e.get(), OnionMessageRecipient::ConnectedPeer(..)
1133 e.get_mut().enqueue_message(onion_message);
1134 log_trace!(logger, "Forwarding an onion message to peer {}", next_node_id);
1136 _ if self.intercept_messages_for_offline_peers => {
1137 self.pending_events.lock().unwrap().push(
1138 Event::OnionMessageIntercepted {
1139 peer_node_id: next_node_id, message: onion_message
1146 "Dropping forwarded onion message to disconnected peer {}",
1153 log_error!(logger, "Failed to process onion message {:?}", e);
1158 fn peer_connected(&self, their_node_id: &PublicKey, init: &msgs::Init, _inbound: bool) -> Result<(), ()> {
1159 if init.features.supports_onion_messages() {
1160 self.message_recipients.lock().unwrap()
1161 .entry(*their_node_id)
1162 .or_insert_with(|| OnionMessageRecipient::ConnectedPeer(VecDeque::new()))
1164 if self.intercept_messages_for_offline_peers {
1165 self.pending_events.lock().unwrap().push(
1166 Event::OnionMessagePeerConnected { peer_node_id: *their_node_id }
1170 self.message_recipients.lock().unwrap().remove(their_node_id);
1176 fn peer_disconnected(&self, their_node_id: &PublicKey) {
1177 match self.message_recipients.lock().unwrap().remove(their_node_id) {
1178 Some(OnionMessageRecipient::ConnectedPeer(..)) => {},
1179 Some(_) => debug_assert!(false),
1184 fn timer_tick_occurred(&self) {
1185 let mut message_recipients = self.message_recipients.lock().unwrap();
1187 // Drop any pending recipients since the last call to avoid retaining buffered messages for
1189 message_recipients.retain(|_, recipient| match recipient {
1190 OnionMessageRecipient::PendingConnection(_, None, ticks) => *ticks < MAX_TIMER_TICKS,
1191 OnionMessageRecipient::PendingConnection(_, Some(_), _) => true,
1195 // Increment a timer tick for pending recipients so that their buffered messages are dropped
1196 // at MAX_TIMER_TICKS.
1197 for recipient in message_recipients.values_mut() {
1198 if let OnionMessageRecipient::PendingConnection(_, None, ticks) = recipient {
1204 fn provided_node_features(&self) -> NodeFeatures {
1205 let mut features = NodeFeatures::empty();
1206 features.set_onion_messages_optional();
1210 fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
1211 let mut features = InitFeatures::empty();
1212 features.set_onion_messages_optional();
1216 // Before returning any messages to send for the peer, this method will see if any messages were
1217 // enqueued in the handler by users, find a path to the corresponding blinded path's introduction
1218 // node, and then enqueue the message for sending to the first peer in the full path.
1219 fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<OnionMessage> {
1220 // Enqueue any initiating `OffersMessage`s to send.
1221 for message in self.offers_handler.release_pending_messages() {
1222 #[cfg(not(c_bindings))]
1223 let PendingOnionMessage { contents, destination, reply_path } = message;
1225 let (contents, destination, reply_path) = message;
1226 let _ = self.find_path_and_enqueue_onion_message(
1227 contents, destination, reply_path, format_args!("when sending OffersMessage")
1231 // Enqueue any initiating `CustomMessage`s to send.
1232 for message in self.custom_handler.release_pending_custom_messages() {
1233 #[cfg(not(c_bindings))]
1234 let PendingOnionMessage { contents, destination, reply_path } = message;
1236 let (contents, destination, reply_path) = message;
1237 let _ = self.find_path_and_enqueue_onion_message(
1238 contents, destination, reply_path, format_args!("when sending CustomMessage")
1242 self.message_recipients.lock().unwrap()
1243 .get_mut(&peer_node_id)
1244 .and_then(|buffer| buffer.dequeue_message())
1248 // TODO: parameterize the below Simple* types with OnionMessenger and handle the messages it
1250 /// Useful for simplifying the parameters of [`SimpleArcChannelManager`] and
1251 /// [`SimpleArcPeerManager`]. See their docs for more details.
1253 /// This is not exported to bindings users as type aliases aren't supported in most languages.
1255 /// [`SimpleArcChannelManager`]: crate::ln::channelmanager::SimpleArcChannelManager
1256 /// [`SimpleArcPeerManager`]: crate::ln::peer_handler::SimpleArcPeerManager
1257 #[cfg(not(c_bindings))]
1258 pub type SimpleArcOnionMessenger<M, T, F, L> = OnionMessenger<
1262 Arc<SimpleArcChannelManager<M, T, F, L>>,
1263 Arc<DefaultMessageRouter<Arc<NetworkGraph<Arc<L>>>, Arc<L>, Arc<KeysManager>>>,
1264 Arc<SimpleArcChannelManager<M, T, F, L>>,
1265 IgnoringMessageHandler
1268 /// Useful for simplifying the parameters of [`SimpleRefChannelManager`] and
1269 /// [`SimpleRefPeerManager`]. See their docs for more details.
1271 /// This is not exported to bindings users as type aliases aren't supported in most languages.
1273 /// [`SimpleRefChannelManager`]: crate::ln::channelmanager::SimpleRefChannelManager
1274 /// [`SimpleRefPeerManager`]: crate::ln::peer_handler::SimpleRefPeerManager
1275 #[cfg(not(c_bindings))]
1276 pub type SimpleRefOnionMessenger<
1277 'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, M, T, F, L
1282 &'i SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L>,
1283 &'j DefaultMessageRouter<&'g NetworkGraph<&'b L>, &'b L, &'a KeysManager>,
1284 &'i SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L>,
1285 IgnoringMessageHandler
1288 /// Construct onion packet payloads and keys for sending an onion message along the given
1289 /// `unblinded_path` to the given `destination`.
1290 fn packet_payloads_and_keys<T: OnionMessageContents, S: secp256k1::Signing + secp256k1::Verification>(
1291 secp_ctx: &Secp256k1<S>, unblinded_path: &[PublicKey], destination: Destination, message: T,
1292 mut reply_path: Option<BlindedPath>, session_priv: &SecretKey
1293 ) -> Result<(Vec<(Payload<T>, [u8; 32])>, Vec<onion_utils::OnionKeys>), SendError> {
1294 let num_hops = unblinded_path.len() + destination.num_hops();
1295 let mut payloads = Vec::with_capacity(num_hops);
1296 let mut onion_packet_keys = Vec::with_capacity(num_hops);
1298 let (mut intro_node_id_blinding_pt, num_blinded_hops) = match &destination {
1299 Destination::Node(_) => (None, 0),
1300 Destination::BlindedPath(BlindedPath { introduction_node, blinding_point, blinded_hops }) => {
1301 let introduction_node_id = match introduction_node {
1302 IntroductionNode::NodeId(pubkey) => pubkey,
1303 IntroductionNode::DirectedShortChannelId(..) => {
1304 return Err(SendError::UnresolvedIntroductionNode);
1307 (Some((*introduction_node_id, *blinding_point)), blinded_hops.len())
1310 let num_unblinded_hops = num_hops - num_blinded_hops;
1312 let mut unblinded_path_idx = 0;
1313 let mut blinded_path_idx = 0;
1314 let mut prev_control_tlvs_ss = None;
1315 let mut final_control_tlvs = None;
1316 utils::construct_keys_callback(secp_ctx, unblinded_path.iter(), Some(destination), session_priv,
1317 |_, onion_packet_ss, ephemeral_pubkey, control_tlvs_ss, unblinded_pk_opt, enc_payload_opt| {
1318 if num_unblinded_hops != 0 && unblinded_path_idx < num_unblinded_hops {
1319 if let Some(ss) = prev_control_tlvs_ss.take() {
1320 payloads.push((Payload::Forward(ForwardControlTlvs::Unblinded(
1322 next_hop: NextHop::NodeId(unblinded_pk_opt.unwrap()),
1323 next_blinding_override: None,
1327 prev_control_tlvs_ss = Some(control_tlvs_ss);
1328 unblinded_path_idx += 1;
1329 } else if let Some((intro_node_id, blinding_pt)) = intro_node_id_blinding_pt.take() {
1330 if let Some(control_tlvs_ss) = prev_control_tlvs_ss.take() {
1331 payloads.push((Payload::Forward(ForwardControlTlvs::Unblinded(ForwardTlvs {
1332 next_hop: NextHop::NodeId(intro_node_id),
1333 next_blinding_override: Some(blinding_pt),
1334 })), control_tlvs_ss));
1337 if blinded_path_idx < num_blinded_hops.saturating_sub(1) && enc_payload_opt.is_some() {
1338 payloads.push((Payload::Forward(ForwardControlTlvs::Blinded(enc_payload_opt.unwrap())),
1340 blinded_path_idx += 1;
1341 } else if let Some(encrypted_payload) = enc_payload_opt {
1342 final_control_tlvs = Some(ReceiveControlTlvs::Blinded(encrypted_payload));
1343 prev_control_tlvs_ss = Some(control_tlvs_ss);
1346 let (rho, mu) = onion_utils::gen_rho_mu_from_shared_secret(onion_packet_ss.as_ref());
1347 onion_packet_keys.push(onion_utils::OnionKeys {
1349 shared_secret: onion_packet_ss,
1351 blinding_factor: [0; 32],
1357 ).map_err(|e| SendError::Secp256k1(e))?;
1359 if let Some(control_tlvs) = final_control_tlvs {
1360 payloads.push((Payload::Receive {
1362 reply_path: reply_path.take(),
1364 }, prev_control_tlvs_ss.unwrap()));
1366 payloads.push((Payload::Receive {
1367 control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id: None, }),
1368 reply_path: reply_path.take(),
1370 }, prev_control_tlvs_ss.unwrap()));
1373 Ok((payloads, onion_packet_keys))
1376 /// Errors if the serialized payload size exceeds onion_message::BIG_PACKET_HOP_DATA_LEN
1377 fn construct_onion_message_packet<T: OnionMessageContents>(payloads: Vec<(Payload<T>, [u8; 32])>, onion_keys: Vec<onion_utils::OnionKeys>, prng_seed: [u8; 32]) -> Result<Packet, ()> {
1379 // "`len` allows larger messages to be sent than the standard 1300 bytes allowed for an HTLC
1380 // onion, but this should be used sparingly as it is reduces anonymity set, hence the
1381 // recommendation that it either look like an HTLC onion, or if larger, be a fixed size."
1382 let payloads_ser_len = onion_utils::payloads_serialized_length(&payloads);
1383 let hop_data_len = if payloads_ser_len <= SMALL_PACKET_HOP_DATA_LEN {
1384 SMALL_PACKET_HOP_DATA_LEN
1385 } else if payloads_ser_len <= BIG_PACKET_HOP_DATA_LEN {
1386 BIG_PACKET_HOP_DATA_LEN
1387 } else { return Err(()) };
1389 onion_utils::construct_onion_message_packet::<_, _>(
1390 payloads, onion_keys, prng_seed, hop_data_len)