X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fonion_message%2Fmessenger.rs;h=723e105d044cf549cfd8f392e206782b38a479af;hb=d974a07e96199932e98f6c34b8f3e1f151b53500;hp=b9269c7cf2c058dc9297b451f029fb068fa06793;hpb=1ceb41e08b2d76b23d2505a10a88db8d840895ca;p=rust-lightning diff --git a/lightning/src/onion_message/messenger.rs b/lightning/src/onion_message/messenger.rs index b9269c7c..723e105d 100644 --- a/lightning/src/onion_message/messenger.rs +++ b/lightning/src/onion_message/messenger.rs @@ -15,27 +15,43 @@ use bitcoin::hashes::hmac::{Hmac, HmacEngine}; use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey}; -use crate::chain::keysinterface::{EntropySource, KeysManager, NodeSigner, Recipient}; -use crate::events::OnionMessageProvider; +use crate::blinded_path::BlindedPath; +use crate::blinded_path::message::{advance_path_by_one, ForwardTlvs, ReceiveTlvs}; +use crate::blinded_path::utils; +use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient}; +use crate::ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager}; use crate::ln::features::{InitFeatures, NodeFeatures}; -use crate::ln::msgs::{self, OnionMessageHandler}; +use crate::ln::msgs::{self, OnionMessage, OnionMessageHandler}; use crate::ln::onion_utils; use crate::ln::peer_handler::IgnoringMessageHandler; -use super::blinded_path::{BlindedPath, ForwardTlvs, ReceiveTlvs}; -pub use super::packet::{CustomOnionMessageContents, OnionMessageContents}; +pub use super::packet::OnionMessageContents; +use super::packet::ParsedOnionMessageContents; +use super::offers::OffersMessageHandler; use super::packet::{BIG_PACKET_HOP_DATA_LEN, ForwardControlTlvs, Packet, Payload, ReceiveControlTlvs, SMALL_PACKET_HOP_DATA_LEN}; -use super::utils; use crate::util::logger::Logger; use crate::util::ser::Writeable; +use core::fmt; use core::ops::Deref; use crate::io; use crate::sync::{Arc, Mutex}; use crate::prelude::*; -/// A sender, receiver and forwarder of onion messages. In upcoming releases, this object will be -/// used to retrieve invoices and fulfill invoice requests from [offers]. Currently, only sending -/// and receiving custom onion messages is supported. +/// A sender, receiver and forwarder of [`OnionMessage`]s. +/// +/// # Handling Messages +/// +/// `OnionMessenger` implements [`OnionMessageHandler`], making it responsible for either forwarding +/// messages to peers or delegating to the appropriate handler for the message type. Currently, the +/// available handlers are: +/// * [`OffersMessageHandler`], for responding to [`InvoiceRequest`]s and paying [`Bolt12Invoice`]s +/// * [`CustomOnionMessageHandler`], for handling user-defined message types +/// +/// # Sending Messages +/// +/// [`OnionMessage`]s are sent initially using [`OnionMessenger::send_onion_message`]. When handling +/// a message, the matched handler may return a response message which `OnionMessenger` will send +/// on its behalf. /// /// # Example /// @@ -43,9 +59,10 @@ use crate::prelude::*; /// # extern crate bitcoin; /// # use bitcoin::hashes::_export::_core::time::Duration; /// # use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey}; -/// # use lightning::chain::keysinterface::KeysManager; +/// # use lightning::blinded_path::BlindedPath; +/// # use lightning::sign::KeysManager; /// # use lightning::ln::peer_handler::IgnoringMessageHandler; -/// # use lightning::onion_message::{BlindedPath, CustomOnionMessageContents, Destination, OnionMessageContents, OnionMessenger}; +/// # use lightning::onion_message::{OnionMessageContents, Destination, MessageRouter, OnionMessagePath, OnionMessenger}; /// # use lightning::util::logger::{Logger, Record}; /// # use lightning::util::ser::{Writeable, Writer}; /// # use lightning::io; @@ -54,6 +71,12 @@ use crate::prelude::*; /// # impl Logger for FakeLogger { /// # fn log(&self, record: &Record) { unimplemented!() } /// # } +/// # struct FakeMessageRouter {} +/// # impl MessageRouter for FakeMessageRouter { +/// # fn find_path(&self, sender: PublicKey, peers: Vec, destination: Destination) -> Result { +/// # unimplemented!() +/// # } +/// # } /// # let seed = [42u8; 32]; /// # let time = Duration::from_secs(123456); /// # let keys_manager = KeysManager::new(&seed, time.as_secs(), time.subsec_nanos()); @@ -63,10 +86,15 @@ use crate::prelude::*; /// # let hop_node_id1 = PublicKey::from_secret_key(&secp_ctx, &node_secret); /// # let (hop_node_id2, hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1, hop_node_id1); /// # let destination_node_id = hop_node_id1; -/// # let your_custom_message_handler = IgnoringMessageHandler {}; +/// # let message_router = Arc::new(FakeMessageRouter {}); +/// # let custom_message_handler = IgnoringMessageHandler {}; +/// # let offers_message_handler = IgnoringMessageHandler {}; /// // Create the onion messenger. This must use the same `keys_manager` as is passed to your /// // ChannelManager. -/// let onion_messenger = OnionMessenger::new(&keys_manager, &keys_manager, logger, &your_custom_message_handler); +/// let onion_messenger = OnionMessenger::new( +/// &keys_manager, &keys_manager, logger, message_router, &offers_message_handler, +/// &custom_message_handler +/// ); /// /// # struct YourCustomMessage {} /// impl Writeable for YourCustomMessage { @@ -75,51 +103,107 @@ use crate::prelude::*; /// // Write your custom onion message to `w` /// } /// } -/// impl CustomOnionMessageContents for YourCustomMessage { +/// impl OnionMessageContents for YourCustomMessage { /// fn tlv_type(&self) -> u64 { /// # let your_custom_message_type = 42; /// your_custom_message_type /// } /// } /// // Send a custom onion message to a node id. -/// let intermediate_hops = [hop_node_id1, hop_node_id2]; +/// let path = OnionMessagePath { +/// intermediate_nodes: vec![hop_node_id1, hop_node_id2], +/// destination: Destination::Node(destination_node_id), +/// }; /// let reply_path = None; -/// # let your_custom_message = YourCustomMessage {}; -/// let message = OnionMessageContents::Custom(your_custom_message); -/// onion_messenger.send_onion_message(&intermediate_hops, Destination::Node(destination_node_id), message, reply_path); +/// # let message = YourCustomMessage {}; +/// onion_messenger.send_onion_message(path, message, reply_path); /// /// // Create a blinded path to yourself, for someone to send an onion message to. /// # let your_node_id = hop_node_id1; /// let hops = [hop_node_id3, hop_node_id4, your_node_id]; -/// let blinded_path = BlindedPath::new(&hops, &keys_manager, &secp_ctx).unwrap(); +/// let blinded_path = BlindedPath::new_for_message(&hops, &keys_manager, &secp_ctx).unwrap(); /// /// // Send a custom onion message to a blinded path. -/// # let intermediate_hops = [hop_node_id1, hop_node_id2]; +/// let path = OnionMessagePath { +/// intermediate_nodes: vec![hop_node_id1, hop_node_id2], +/// destination: Destination::BlindedPath(blinded_path), +/// }; /// let reply_path = None; -/// # let your_custom_message = YourCustomMessage {}; -/// let message = OnionMessageContents::Custom(your_custom_message); -/// onion_messenger.send_onion_message(&intermediate_hops, Destination::BlindedPath(blinded_path), message, reply_path); +/// # let message = YourCustomMessage {}; +/// onion_messenger.send_onion_message(path, message, reply_path); /// ``` /// -/// [offers]: -/// [`OnionMessenger`]: crate::onion_message::OnionMessenger -pub struct OnionMessenger - where ES::Target: EntropySource, - NS::Target: NodeSigner, - L::Target: Logger, - CMH:: Target: CustomOnionMessageHandler, +/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest +/// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice +pub struct OnionMessenger +where + ES::Target: EntropySource, + NS::Target: NodeSigner, + L::Target: Logger, + MR::Target: MessageRouter, + OMH::Target: OffersMessageHandler, + CMH:: Target: CustomOnionMessageHandler, { entropy_source: ES, node_signer: NS, logger: L, - pending_messages: Mutex>>, + pending_messages: Mutex>>, secp_ctx: Secp256k1, + message_router: MR, + offers_handler: OMH, custom_handler: CMH, - // Coming soon: - // invoice_handler: InvoiceHandler, +} + +/// An [`OnionMessage`] for [`OnionMessenger`] to send. +/// +/// These are obtained when released from [`OnionMessenger`]'s handlers after which they are +/// enqueued for sending. +pub struct PendingOnionMessage { + /// The message contents to send in an [`OnionMessage`]. + pub contents: T, + + /// The destination of the message. + pub destination: Destination, + + /// A reply path to include in the [`OnionMessage`] for a response. + pub reply_path: Option, +} + +/// A trait defining behavior for routing an [`OnionMessage`]. +pub trait MessageRouter { + /// Returns a route for sending an [`OnionMessage`] to the given [`Destination`]. + fn find_path( + &self, sender: PublicKey, peers: Vec, destination: Destination + ) -> Result; +} + +/// A [`MessageRouter`] that can only route to a directly connected [`Destination`]. +pub struct DefaultMessageRouter; + +impl MessageRouter for DefaultMessageRouter { + fn find_path( + &self, _sender: PublicKey, peers: Vec, destination: Destination + ) -> Result { + if peers.contains(&destination.first_node()) { + Ok(OnionMessagePath { intermediate_nodes: vec![], destination }) + } else { + Err(()) + } + } +} + +/// A path for sending an [`OnionMessage`]. +#[derive(Clone)] +pub struct OnionMessagePath { + /// Nodes on the path between the sender and the destination. + pub intermediate_nodes: Vec, + + /// The recipient of the message. + pub destination: Destination, } /// The destination of an onion message. +#[derive(Clone)] pub enum Destination { /// We're sending this onion message to a node. Node(PublicKey), @@ -134,6 +218,13 @@ impl Destination { Destination::BlindedPath(BlindedPath { blinded_hops, .. }) => blinded_hops.len(), } } + + fn first_node(&self) -> PublicKey { + match self { + Destination::Node(node_id) => *node_id, + Destination::BlindedPath(BlindedPath { introduction_node_id: node_id, .. }) => *node_id, + } + } } /// Errors that may occur when [sending an onion message]. @@ -146,8 +237,8 @@ pub enum SendError { /// Because implementations such as Eclair will drop onion messages where the message packet /// exceeds 32834 bytes, we refuse to send messages where the packet exceeds this size. TooBigPacket, - /// The provided [`Destination`] was an invalid [`BlindedPath`], due to having fewer than two - /// blinded hops. + /// The provided [`Destination`] was an invalid [`BlindedPath`] due to not having any blinded + /// hops. TooFewBlindedHops, /// Our next-hop peer was offline or does not support onion message forwarding. InvalidFirstHop, @@ -157,7 +248,7 @@ pub enum SendError { BufferFull, /// Failed to retrieve our node id from the provided [`NodeSigner`]. /// - /// [`NodeSigner`]: crate::chain::keysinterface::NodeSigner + /// [`NodeSigner`]: crate::sign::NodeSigner GetNodeIdFailed, /// We attempted to send to a blinded path where we are the introduction node, and failed to /// advance the blinded path to make the second hop the new introduction node. Either @@ -179,23 +270,205 @@ pub enum SendError { pub trait CustomOnionMessageHandler { /// The message known to the handler. To support multiple message types, you may want to make this /// an enum with a variant for each supported message. - type CustomMessage: CustomOnionMessageContents; - /// Called with the custom message that was received. - fn handle_custom_message(&self, msg: Self::CustomMessage); + type CustomMessage: OnionMessageContents; + + /// Called with the custom message that was received, returning a response to send, if any. + /// + /// The returned [`Self::CustomMessage`], if any, is enqueued to be sent by [`OnionMessenger`]. + fn handle_custom_message(&self, msg: Self::CustomMessage) -> Option; + /// Read a custom message of type `message_type` from `buffer`, returning `Ok(None)` if the /// message type is unknown. fn read_custom_message(&self, message_type: u64, buffer: &mut R) -> Result, msgs::DecodeError>; + + /// Releases any [`Self::CustomMessage`]s that need to be sent. + /// + /// Typically, this is used for messages initiating a message flow rather than in response to + /// another message. The latter should use the return value of [`Self::handle_custom_message`]. + fn release_pending_custom_messages(&self) -> Vec>; +} + +/// A processed incoming onion message, containing either a Forward (another onion message) +/// or a Receive payload with decrypted contents. +pub enum PeeledOnion { + /// Forwarded onion, with the next node id and a new onion + Forward(PublicKey, OnionMessage), + /// Received onion message, with decrypted contents, path_id, and reply path + Receive(ParsedOnionMessageContents, Option<[u8; 32]>, Option) +} + +/// Creates an [`OnionMessage`] with the given `contents` for sending to the destination of +/// `path`. +/// +/// Returns both the node id of the peer to send the message to and the message itself. +pub fn create_onion_message( + entropy_source: &ES, node_signer: &NS, secp_ctx: &Secp256k1, + path: OnionMessagePath, contents: T, reply_path: Option, +) -> Result<(PublicKey, OnionMessage), SendError> +where + ES::Target: EntropySource, + NS::Target: NodeSigner, +{ + let OnionMessagePath { intermediate_nodes, mut destination } = path; + if let Destination::BlindedPath(BlindedPath { ref blinded_hops, .. }) = destination { + if blinded_hops.is_empty() { + return Err(SendError::TooFewBlindedHops); + } + } + + if contents.tlv_type() < 64 { return Err(SendError::InvalidMessage) } + + // If we are sending straight to a blinded path and we are the introduction node, we need to + // advance the blinded path by 1 hop so the second hop is the new introduction node. + if intermediate_nodes.len() == 0 { + if let Destination::BlindedPath(ref mut blinded_path) = destination { + let our_node_id = node_signer.get_node_id(Recipient::Node) + .map_err(|()| SendError::GetNodeIdFailed)?; + if blinded_path.introduction_node_id == our_node_id { + advance_path_by_one(blinded_path, node_signer, &secp_ctx) + .map_err(|()| SendError::BlindedPathAdvanceFailed)?; + } + } + } + + let blinding_secret_bytes = entropy_source.get_secure_random_bytes(); + let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted"); + let (first_node_id, blinding_point) = if let Some(first_node_id) = intermediate_nodes.first() { + (*first_node_id, PublicKey::from_secret_key(&secp_ctx, &blinding_secret)) + } else { + match destination { + Destination::Node(pk) => (pk, PublicKey::from_secret_key(&secp_ctx, &blinding_secret)), + Destination::BlindedPath(BlindedPath { introduction_node_id, blinding_point, .. }) => + (introduction_node_id, blinding_point), + } + }; + let (packet_payloads, packet_keys) = packet_payloads_and_keys( + &secp_ctx, &intermediate_nodes, destination, contents, reply_path, &blinding_secret) + .map_err(|e| SendError::Secp256k1(e))?; + + let prng_seed = entropy_source.get_secure_random_bytes(); + let onion_routing_packet = construct_onion_message_packet( + packet_payloads, packet_keys, prng_seed).map_err(|()| SendError::TooBigPacket)?; + + Ok((first_node_id, OnionMessage { + blinding_point, + onion_routing_packet + })) +} + +/// Decode one layer of an incoming [`OnionMessage`]. +/// +/// Returns either the next layer of the onion for forwarding or the decrypted content for the +/// receiver. +pub fn peel_onion_message( + msg: &OnionMessage, secp_ctx: &Secp256k1, node_signer: NS, logger: L, + custom_handler: CMH, +) -> Result::Target as CustomOnionMessageHandler>::CustomMessage>, ()> +where + NS::Target: NodeSigner, + L::Target: Logger, + CMH::Target: CustomOnionMessageHandler, +{ + let control_tlvs_ss = match node_signer.ecdh(Recipient::Node, &msg.blinding_point, None) { + Ok(ss) => ss, + Err(e) => { + log_error!(logger, "Failed to retrieve node secret: {:?}", e); + return Err(()); + } + }; + let onion_decode_ss = { + let blinding_factor = { + let mut hmac = HmacEngine::::new(b"blinded_node_id"); + hmac.input(control_tlvs_ss.as_ref()); + Hmac::from_engine(hmac).into_inner() + }; + match node_signer.ecdh(Recipient::Node, &msg.onion_routing_packet.public_key, + Some(&Scalar::from_be_bytes(blinding_factor).unwrap())) + { + Ok(ss) => ss.secret_bytes(), + Err(()) => { + log_trace!(logger, "Failed to compute onion packet shared secret"); + return Err(()); + } + } + }; + match onion_utils::decode_next_untagged_hop( + onion_decode_ss, &msg.onion_routing_packet.hop_data[..], msg.onion_routing_packet.hmac, + (control_tlvs_ss, custom_handler.deref(), logger.deref()) + ) { + Ok((Payload::Receive::::Target as CustomOnionMessageHandler>::CustomMessage>> { + message, control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path, + }, None)) => { + Ok(PeeledOnion::Receive(message, path_id, reply_path)) + }, + Ok((Payload::Forward(ForwardControlTlvs::Unblinded(ForwardTlvs { + next_node_id, next_blinding_override + })), Some((next_hop_hmac, new_packet_bytes)))) => { + // TODO: we need to check whether `next_node_id` is our node, in which case this is a dummy + // blinded hop and this onion message is destined for us. In this situation, we should keep + // unwrapping the onion layers to get to the final payload. Since we don't have the option + // of creating blinded paths with dummy hops currently, we should be ok to not handle this + // for now. + let new_pubkey = match onion_utils::next_hop_pubkey(&secp_ctx, msg.onion_routing_packet.public_key, &onion_decode_ss) { + Ok(pk) => pk, + Err(e) => { + log_trace!(logger, "Failed to compute next hop packet pubkey: {}", e); + return Err(()) + } + }; + let outgoing_packet = Packet { + version: 0, + public_key: new_pubkey, + hop_data: new_packet_bytes, + hmac: next_hop_hmac, + }; + let onion_message = OnionMessage { + blinding_point: match next_blinding_override { + Some(blinding_point) => blinding_point, + None => { + match onion_utils::next_hop_pubkey( + &secp_ctx, msg.blinding_point, control_tlvs_ss.as_ref() + ) { + Ok(bp) => bp, + Err(e) => { + log_trace!(logger, "Failed to compute next blinding point: {}", e); + return Err(()) + } + } + } + }, + onion_routing_packet: outgoing_packet, + }; + + Ok(PeeledOnion::Forward(next_node_id, onion_message)) + }, + Err(e) => { + log_trace!(logger, "Errored decoding onion message packet: {:?}", e); + Err(()) + }, + _ => { + log_trace!(logger, "Received bogus onion message packet, either the sender encoded a final hop as a forwarding hop or vice versa"); + Err(()) + }, + } } -impl OnionMessenger - where ES::Target: EntropySource, - NS::Target: NodeSigner, - L::Target: Logger, - CMH::Target: CustomOnionMessageHandler, +impl +OnionMessenger +where + ES::Target: EntropySource, + NS::Target: NodeSigner, + L::Target: Logger, + MR::Target: MessageRouter, + OMH::Target: OffersMessageHandler, + CMH::Target: CustomOnionMessageHandler, { /// Constructs a new `OnionMessenger` to send, forward, and delegate received onion messages to /// their respective handlers. - pub fn new(entropy_source: ES, node_signer: NS, logger: L, custom_handler: CMH) -> Self { + pub fn new( + entropy_source: ES, node_signer: NS, logger: L, message_router: MR, offers_handler: OMH, + custom_handler: CMH + ) -> Self { let mut secp_ctx = Secp256k1::new(); secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); OnionMessenger { @@ -204,66 +477,82 @@ impl OnionMessenger pending_messages: Mutex::new(HashMap::new()), secp_ctx, logger, + message_router, + offers_handler, custom_handler, } } - /// Send an onion message with contents `message` to `destination`, routing it through `intermediate_nodes`. + /// Sends an [`OnionMessage`] with the given `contents` for sending to the destination of + /// `path`. + /// /// See [`OnionMessenger`] for example usage. - pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], mut destination: Destination, message: OnionMessageContents, reply_path: Option) -> Result<(), SendError> { - if let Destination::BlindedPath(BlindedPath { ref blinded_hops, .. }) = destination { - if blinded_hops.len() < 2 { - return Err(SendError::TooFewBlindedHops); + pub fn send_onion_message( + &self, path: OnionMessagePath, contents: T, reply_path: Option + ) -> Result<(), SendError> { + let (first_node_id, onion_msg) = create_onion_message( + &self.entropy_source, &self.node_signer, &self.secp_ctx, path, contents, reply_path + )?; + + let mut pending_per_peer_msgs = self.pending_messages.lock().unwrap(); + if outbound_buffer_full(&first_node_id, &pending_per_peer_msgs) { return Err(SendError::BufferFull) } + match pending_per_peer_msgs.entry(first_node_id) { + hash_map::Entry::Vacant(_) => Err(SendError::InvalidFirstHop), + hash_map::Entry::Occupied(mut e) => { + e.get_mut().push_back(onion_msg); + Ok(()) } } - let OnionMessageContents::Custom(ref msg) = message; - if msg.tlv_type() < 64 { return Err(SendError::InvalidMessage) } - - // If we are sending straight to a blinded path and we are the introduction node, we need to - // advance the blinded path by 1 hop so the second hop is the new introduction node. - if intermediate_nodes.len() == 0 { - if let Destination::BlindedPath(ref mut blinded_path) = destination { - let our_node_id = self.node_signer.get_node_id(Recipient::Node) - .map_err(|()| SendError::GetNodeIdFailed)?; - if blinded_path.introduction_node_id == our_node_id { - blinded_path.advance_by_one(&self.node_signer, &self.secp_ctx) - .map_err(|()| SendError::BlindedPathAdvanceFailed)?; - } + } + + fn handle_onion_message_response( + &self, response: Option, reply_path: Option, log_suffix: fmt::Arguments + ) { + if let Some(response) = response { + match reply_path { + Some(reply_path) => { + self.find_path_and_enqueue_onion_message( + response, Destination::BlindedPath(reply_path), None, log_suffix + ); + }, + None => { + log_trace!(self.logger, "Missing reply path {}", log_suffix); + }, } } + } - let blinding_secret_bytes = self.entropy_source.get_secure_random_bytes(); - let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted"); - let (introduction_node_id, blinding_point) = if intermediate_nodes.len() != 0 { - (intermediate_nodes[0], PublicKey::from_secret_key(&self.secp_ctx, &blinding_secret)) - } else { - match destination { - Destination::Node(pk) => (pk, PublicKey::from_secret_key(&self.secp_ctx, &blinding_secret)), - Destination::BlindedPath(BlindedPath { introduction_node_id, blinding_point, .. }) => - (introduction_node_id, blinding_point), + fn find_path_and_enqueue_onion_message( + &self, contents: T, destination: Destination, reply_path: Option, + log_suffix: fmt::Arguments + ) { + let sender = match self.node_signer.get_node_id(Recipient::Node) { + Ok(node_id) => node_id, + Err(_) => { + log_warn!(self.logger, "Unable to retrieve node id {}", log_suffix); + return; } }; - let (packet_payloads, packet_keys) = packet_payloads_and_keys( - &self.secp_ctx, intermediate_nodes, destination, message, reply_path, &blinding_secret) - .map_err(|e| SendError::Secp256k1(e))?; - let prng_seed = self.entropy_source.get_secure_random_bytes(); - let onion_routing_packet = construct_onion_message_packet( - packet_payloads, packet_keys, prng_seed).map_err(|()| SendError::TooBigPacket)?; + let peers = self.pending_messages.lock().unwrap().keys().copied().collect(); + let path = match self.message_router.find_path(sender, peers, destination) { + Ok(path) => path, + Err(()) => { + log_trace!(self.logger, "Failed to find path {}", log_suffix); + return; + }, + }; - let mut pending_per_peer_msgs = self.pending_messages.lock().unwrap(); - if outbound_buffer_full(&introduction_node_id, &pending_per_peer_msgs) { return Err(SendError::BufferFull) } - match pending_per_peer_msgs.entry(introduction_node_id) { - hash_map::Entry::Vacant(_) => Err(SendError::InvalidFirstHop), - hash_map::Entry::Occupied(mut e) => { - e.get_mut().push_back(msgs::OnionMessage { blinding_point, onion_routing_packet }); - Ok(()) - } + log_trace!(self.logger, "Sending onion message {}", log_suffix); + + if let Err(e) = self.send_onion_message(path, contents, reply_path) { + log_trace!(self.logger, "Failed sending onion message {}: {:?}", log_suffix, e); + return; } } #[cfg(test)] - pub(super) fn release_pending_msgs(&self) -> HashMap> { + pub(super) fn release_pending_msgs(&self) -> HashMap> { let mut pending_msgs = self.pending_messages.lock().unwrap(); let mut msgs = HashMap::new(); // We don't want to disconnect the peers by removing them entirely from the original map, so we @@ -275,7 +564,7 @@ impl OnionMessenger } } -fn outbound_buffer_full(peer_node_id: &PublicKey, buffer: &HashMap>) -> bool { +fn outbound_buffer_full(peer_node_id: &PublicKey, buffer: &HashMap>) -> bool { const MAX_TOTAL_BUFFER_SIZE: usize = (1 << 20) * 128; const MAX_PER_PEER_BUFFER_SIZE: usize = (1 << 10) * 256; let mut total_buffered_bytes = 0; @@ -298,96 +587,47 @@ fn outbound_buffer_full(peer_node_id: &PublicKey, buffer: &HashMap OnionMessageHandler for OnionMessenger - where ES::Target: EntropySource, - NS::Target: NodeSigner, - L::Target: Logger, - CMH::Target: CustomOnionMessageHandler + Sized, +impl OnionMessageHandler +for OnionMessenger +where + ES::Target: EntropySource, + NS::Target: NodeSigner, + L::Target: Logger, + MR::Target: MessageRouter, + OMH::Target: OffersMessageHandler, + CMH::Target: CustomOnionMessageHandler, { - /// Handle an incoming onion message. Currently, if a message was destined for us we will log, but - /// soon we'll delegate the onion message to a handler that can generate invoices or send - /// payments. - fn handle_onion_message(&self, _peer_node_id: &PublicKey, msg: &msgs::OnionMessage) { - let control_tlvs_ss = match self.node_signer.ecdh(Recipient::Node, &msg.blinding_point, None) { - Ok(ss) => ss, - Err(e) => { - log_error!(self.logger, "Failed to retrieve node secret: {:?}", e); - return - } - }; - let onion_decode_ss = { - let blinding_factor = { - let mut hmac = HmacEngine::::new(b"blinded_node_id"); - hmac.input(control_tlvs_ss.as_ref()); - Hmac::from_engine(hmac).into_inner() - }; - match self.node_signer.ecdh(Recipient::Node, &msg.onion_routing_packet.public_key, - Some(&Scalar::from_be_bytes(blinding_factor).unwrap())) - { - Ok(ss) => ss.secret_bytes(), - Err(()) => { - log_trace!(self.logger, "Failed to compute onion packet shared secret"); - return - } - } - }; - match onion_utils::decode_next_untagged_hop(onion_decode_ss, &msg.onion_routing_packet.hop_data[..], - msg.onion_routing_packet.hmac, (control_tlvs_ss, &*self.custom_handler)) - { - Ok((Payload::Receive::<<::Target as CustomOnionMessageHandler>::CustomMessage> { - message, control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path, - }, None)) => { - log_info!(self.logger, + fn handle_onion_message(&self, _peer_node_id: &PublicKey, msg: &OnionMessage) { + match peel_onion_message( + msg, &self.secp_ctx, &*self.node_signer, &*self.logger, &*self.custom_handler + ) { + Ok(PeeledOnion::Receive(message, path_id, reply_path)) => { + log_trace!(self.logger, "Received an onion message with path_id {:02x?} and {} reply_path", path_id, if reply_path.is_some() { "a" } else { "no" }); + match message { - OnionMessageContents::Custom(msg) => self.custom_handler.handle_custom_message(msg), + ParsedOnionMessageContents::Offers(msg) => { + let response = self.offers_handler.handle_message(msg); + self.handle_onion_message_response( + response, reply_path, format_args!( + "when responding to Offers onion message with path_id {:02x?}", + path_id + ) + ); + }, + ParsedOnionMessageContents::Custom(msg) => { + let response = self.custom_handler.handle_custom_message(msg); + self.handle_onion_message_response( + response, reply_path, format_args!( + "when responding to Custom onion message with path_id {:02x?}", + path_id + ) + ); + }, } }, - Ok((Payload::Forward(ForwardControlTlvs::Unblinded(ForwardTlvs { - next_node_id, next_blinding_override - })), Some((next_hop_hmac, new_packet_bytes)))) => { - // TODO: we need to check whether `next_node_id` is our node, in which case this is a dummy - // blinded hop and this onion message is destined for us. In this situation, we should keep - // unwrapping the onion layers to get to the final payload. Since we don't have the option - // of creating blinded paths with dummy hops currently, we should be ok to not handle this - // for now. - let new_pubkey = match onion_utils::next_hop_packet_pubkey(&self.secp_ctx, msg.onion_routing_packet.public_key, &onion_decode_ss) { - Ok(pk) => pk, - Err(e) => { - log_trace!(self.logger, "Failed to compute next hop packet pubkey: {}", e); - return - } - }; - let outgoing_packet = Packet { - version: 0, - public_key: new_pubkey, - hop_data: new_packet_bytes, - hmac: next_hop_hmac, - }; - let onion_message = msgs::OnionMessage { - blinding_point: match next_blinding_override { - Some(blinding_point) => blinding_point, - None => { - let blinding_factor = { - let mut sha = Sha256::engine(); - sha.input(&msg.blinding_point.serialize()[..]); - sha.input(control_tlvs_ss.as_ref()); - Sha256::from_engine(sha).into_inner() - }; - let next_blinding_point = msg.blinding_point; - match next_blinding_point.mul_tweak(&self.secp_ctx, &Scalar::from_be_bytes(blinding_factor).unwrap()) { - Ok(bp) => bp, - Err(e) => { - log_trace!(self.logger, "Failed to compute next blinding point: {}", e); - return - } - } - }, - }, - onion_routing_packet: outgoing_packet, - }; - + Ok(PeeledOnion::Forward(next_node_id, onion_message)) => { let mut pending_per_peer_msgs = self.pending_messages.lock().unwrap(); if outbound_buffer_full(&next_node_id, &pending_per_peer_msgs) { log_trace!(self.logger, "Dropping forwarded onion message to peer {:?}: outbound buffer full", next_node_id); @@ -406,15 +646,12 @@ impl OnionMessageHandler for OnionMe e.get_mut().push_back(onion_message); log_trace!(self.logger, "Forwarding an onion message to peer {}", next_node_id); } - }; + } }, Err(e) => { - log_trace!(self.logger, "Errored decoding onion message packet: {:?}", e); - }, - _ => { - log_trace!(self.logger, "Received bogus onion message packet, either the sender encoded a final hop as a forwarding hop or vice versa"); - }, - }; + log_error!(self.logger, "Failed to process onion message {:?}", e); + } + } } fn peer_connected(&self, their_node_id: &PublicKey, init: &msgs::Init, _inbound: bool) -> Result<(), ()> { @@ -441,15 +678,27 @@ impl OnionMessageHandler for OnionMe features.set_onion_messages_optional(); features } -} -impl OnionMessageProvider for OnionMessenger - where ES::Target: EntropySource, - NS::Target: NodeSigner, - L::Target: Logger, - CMH::Target: CustomOnionMessageHandler, -{ - fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option { + // Before returning any messages to send for the peer, this method will see if any messages were + // enqueued in the handler by users, find a path to the corresponding blinded path's introduction + // node, and then enqueue the message for sending to the first peer in the full path. + fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option { + // Enqueue any initiating `OffersMessage`s to send. + for message in self.offers_handler.release_pending_messages() { + let PendingOnionMessage { contents, destination, reply_path } = message; + self.find_path_and_enqueue_onion_message( + contents, destination, reply_path, format_args!("when sending OffersMessage") + ); + } + + // Enqueue any initiating `CustomMessage`s to send. + for message in self.custom_handler.release_pending_custom_messages() { + let PendingOnionMessage { contents, destination, reply_path } = message; + self.find_path_and_enqueue_onion_message( + contents, destination, reply_path, format_args!("when sending CustomMessage") + ); + } + let mut pending_msgs = self.pending_messages.lock().unwrap(); if let Some(msgs) = pending_msgs.get_mut(&peer_node_id) { return msgs.pop_front() @@ -467,7 +716,15 @@ impl OnionMessageProvider for OnionM /// /// [`SimpleArcChannelManager`]: crate::ln::channelmanager::SimpleArcChannelManager /// [`SimpleArcPeerManager`]: crate::ln::peer_handler::SimpleArcPeerManager -pub type SimpleArcOnionMessenger = OnionMessenger, Arc, Arc, IgnoringMessageHandler>; +pub type SimpleArcOnionMessenger = OnionMessenger< + Arc, + Arc, + Arc, + Arc, + Arc>, + IgnoringMessageHandler +>; + /// Useful for simplifying the parameters of [`SimpleRefChannelManager`] and /// [`SimpleRefPeerManager`]. See their docs for more details. /// @@ -475,13 +732,22 @@ pub type SimpleArcOnionMessenger = OnionMessenger, Arc = OnionMessenger<&'a KeysManager, &'a KeysManager, &'b L, IgnoringMessageHandler>; +pub type SimpleRefOnionMessenger< + 'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, M, T, F, L +> = OnionMessenger< + &'a KeysManager, + &'a KeysManager, + &'b L, + &'i DefaultMessageRouter, + &'j SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L>, + IgnoringMessageHandler +>; /// Construct onion packet payloads and keys for sending an onion message along the given /// `unblinded_path` to the given `destination`. -fn packet_payloads_and_keys( - secp_ctx: &Secp256k1, unblinded_path: &[PublicKey], destination: Destination, - message: OnionMessageContents, mut reply_path: Option, session_priv: &SecretKey +fn packet_payloads_and_keys( + secp_ctx: &Secp256k1, unblinded_path: &[PublicKey], destination: Destination, message: T, + mut reply_path: Option, session_priv: &SecretKey ) -> Result<(Vec<(Payload, [u8; 32])>, Vec), secp256k1::Error> { let num_hops = unblinded_path.len() + destination.num_hops(); let mut payloads = Vec::with_capacity(num_hops); @@ -496,46 +762,48 @@ fn packet_payloads_and_keys(payloads: Vec<(Payload, [u8; 32])>, onion_keys: Vec, prng_seed: [u8; 32]) -> Result { +fn construct_onion_message_packet(payloads: Vec<(Payload, [u8; 32])>, onion_keys: Vec, prng_seed: [u8; 32]) -> Result { // Spec rationale: // "`len` allows larger messages to be sent than the standard 1300 bytes allowed for an HTLC // onion, but this should be used sparingly as it is reduces anonymity set, hence the @@ -567,6 +835,6 @@ fn construct_onion_message_packet(payloads: Vec<( BIG_PACKET_HOP_DATA_LEN } else { return Err(()) }; - Ok(onion_utils::construct_onion_message_packet::<_, _>( - payloads, onion_keys, prng_seed, hop_data_len)) + onion_utils::construct_onion_message_packet::<_, _>( + payloads, onion_keys, prng_seed, hop_data_len) }