From 6500c99f29d626c78c7848586a0018453f64fe45 Mon Sep 17 00:00:00 2001 From: Valentine Wallace Date: Thu, 23 Jun 2022 15:47:25 -0400 Subject: [PATCH] Add SendError enum for onion messages and error on too-big packets --- .../src/onion_message/functional_tests.rs | 18 ++++++++++-- lightning/src/onion_message/messenger.rs | 28 +++++++++++++++---- lightning/src/onion_message/mod.rs | 2 +- 3 files changed, 39 insertions(+), 9 deletions(-) diff --git a/lightning/src/onion_message/functional_tests.rs b/lightning/src/onion_message/functional_tests.rs index 510852cef..560028c5b 100644 --- a/lightning/src/onion_message/functional_tests.rs +++ b/lightning/src/onion_message/functional_tests.rs @@ -10,12 +10,12 @@ //! Onion message testing and test utilities live here. use chain::keysinterface::{KeysInterface, Recipient}; -use super::{BlindedRoute, Destination, OnionMessenger}; +use super::{BlindedRoute, Destination, OnionMessenger, SendError}; use util::enforcing_trait_impls::EnforcingSigner; use util::test_utils; use bitcoin::network::constants::Network; -use bitcoin::secp256k1::{PublicKey, Secp256k1}; +use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey}; use sync::Arc; @@ -105,3 +105,17 @@ fn three_blinded_hops() { nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route)).unwrap(); pass_along_path(nodes, None); } + +#[test] +fn too_big_packet_error() { + // Make sure we error as expected if a packet is too big to send. + let nodes = create_nodes(1); + + let hop_secret = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap(); + let secp_ctx = Secp256k1::new(); + let hop_node_id = PublicKey::from_secret_key(&secp_ctx, &hop_secret); + + let hops = [hop_node_id; 400]; + let err = nodes[0].messenger.send_onion_message(&hops, Destination::Node(hop_node_id)).unwrap_err(); + assert_eq!(err, SendError::TooBigPacket); +} diff --git a/lightning/src/onion_message/messenger.rs b/lightning/src/onion_message/messenger.rs index 930d90eba..6f5d9e8a5 100644 --- a/lightning/src/onion_message/messenger.rs +++ b/lightning/src/onion_message/messenger.rs @@ -108,6 +108,18 @@ impl Destination { } } +/// Errors that may occur when [sending an onion message]. +/// +/// [sending an onion message]: OnionMessenger::send_onion_message +#[derive(Debug, PartialEq)] +pub enum SendError { + /// Errored computing onion message packet keys. + Secp256k1(secp256k1::Error), + /// 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, +} + impl OnionMessenger where K::Target: KeysInterface, L::Target: Logger, @@ -127,7 +139,7 @@ impl OnionMessenger /// Send an empty onion message to `destination`, routing it through `intermediate_nodes`. /// See [`OnionMessenger`] for example usage. - pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], destination: Destination) -> Result<(), secp256k1::Error> { + pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], destination: Destination) -> Result<(), SendError> { let blinding_secret_bytes = self.keys_manager.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 { @@ -140,10 +152,12 @@ impl OnionMessenger } }; let (packet_payloads, packet_keys) = packet_payloads_and_keys( - &self.secp_ctx, intermediate_nodes, destination, &blinding_secret)?; + &self.secp_ctx, intermediate_nodes, destination, &blinding_secret) + .map_err(|e| SendError::Secp256k1(e))?; let prng_seed = self.keys_manager.get_secure_random_bytes(); - let onion_packet = construct_onion_message_packet(packet_payloads, packet_keys, prng_seed); + let onion_packet = construct_onion_message_packet( + packet_payloads, packet_keys, prng_seed).map_err(|()| SendError::TooBigPacket)?; let mut pending_per_peer_msgs = self.pending_messages.lock().unwrap(); let pending_msgs = pending_per_peer_msgs.entry(introduction_node_id).or_insert(Vec::new()); @@ -343,7 +357,8 @@ fn packet_payloads_and_keys( Ok((payloads, onion_packet_keys)) } -fn construct_onion_message_packet(payloads: Vec<(Payload, [u8; 32])>, onion_keys: Vec, prng_seed: [u8; 32]) -> Packet { +/// Errors if the serialized payload size exceeds onion_message::BIG_PACKET_HOP_DATA_LEN +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 @@ -353,7 +368,8 @@ fn construct_onion_message_packet(payloads: Vec<(Payload, [u8; 32])>, onion_keys SMALL_PACKET_HOP_DATA_LEN } else if payloads_ser_len <= BIG_PACKET_HOP_DATA_LEN { BIG_PACKET_HOP_DATA_LEN - } else { payloads_ser_len }; + } else { return Err(()) }; - onion_utils::construct_onion_message_packet::<_, _>(payloads, onion_keys, prng_seed, hop_data_len) + Ok(onion_utils::construct_onion_message_packet::<_, _>( + payloads, onion_keys, prng_seed, hop_data_len)) } diff --git a/lightning/src/onion_message/mod.rs b/lightning/src/onion_message/mod.rs index 966b10b60..2e23b76ad 100644 --- a/lightning/src/onion_message/mod.rs +++ b/lightning/src/onion_message/mod.rs @@ -29,5 +29,5 @@ mod functional_tests; // Re-export structs so they can be imported with just the `onion_message::` module prefix. pub use self::blinded_route::{BlindedRoute, BlindedHop}; -pub use self::messenger::{Destination, OnionMessenger, SimpleArcOnionMessenger, SimpleRefOnionMessenger}; +pub use self::messenger::{Destination, OnionMessenger, SendError, SimpleArcOnionMessenger, SimpleRefOnionMessenger}; pub(crate) use self::packet::Packet; -- 2.39.5