From c126f0b1870552d03b011afd4104a22fb523007a Mon Sep 17 00:00:00 2001 From: Evan Feenstra Date: Sat, 28 Oct 2023 15:10:00 -0700 Subject: [PATCH] public create_payment_onion in onion_utils --- lightning/src/ln/channelmanager.rs | 10 ++++------ lightning/src/ln/mod.rs | 1 + lightning/src/ln/msgs.rs | 14 +++++++++----- lightning/src/ln/onion_utils.rs | 21 +++++++++++++++++++++ 4 files changed, 35 insertions(+), 11 deletions(-) diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index c4efd8957..9f86095d6 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -3420,12 +3420,10 @@ where let prng_seed = self.entropy_source.get_secure_random_bytes(); let session_priv = SecretKey::from_slice(&session_priv_bytes[..]).expect("RNG is busted"); - let onion_keys = onion_utils::construct_onion_keys(&self.secp_ctx, &path, &session_priv) - .map_err(|_| APIError::InvalidRoute{err: "Pubkey along hop was maliciously selected".to_owned()})?; - let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(path, total_value, recipient_onion, cur_height, keysend_preimage)?; - - let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash) - .map_err(|_| APIError::InvalidRoute { err: "Route size too large considering onion data".to_owned()})?; + let (onion_packet, htlc_msat, htlc_cltv) = onion_utils::create_payment_onion( + &self.secp_ctx, &path, &session_priv, total_value, recipient_onion, cur_height, + payment_hash, keysend_preimage, prng_seed + )?; let err: Result<(), _> = loop { let (counterparty_node_id, id) = match self.short_to_chan_info.read().unwrap().get(&path.hops.first().unwrap().short_channel_id) { diff --git a/lightning/src/ln/mod.rs b/lightning/src/ln/mod.rs index beefd2d46..041c196f6 100644 --- a/lightning/src/ln/mod.rs +++ b/lightning/src/ln/mod.rs @@ -39,6 +39,7 @@ pub(crate) mod onion_utils; mod outbound_payment; pub mod wire; +pub use onion_utils::create_payment_onion; // Older rustc (which we support) refuses to let us call the get_payment_preimage_hash!() macro // without the node parameter being mut. This is incorrect, and thus newer rustcs will complain // about an unnecessary mut. Thus, we silence the unused_mut warning in two test modules below. diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs index 6043bf35b..d43ad6d0a 100644 --- a/lightning/src/ln/msgs.rs +++ b/lightning/src/ln/msgs.rs @@ -1674,17 +1674,21 @@ pub use self::fuzzy_internal_msgs::*; #[cfg(not(fuzzing))] pub(crate) use self::fuzzy_internal_msgs::*; +/// BOLT 4 onion packet including hop data for the next peer. #[derive(Clone)] -pub(crate) struct OnionPacket { - pub(crate) version: u8, +pub struct OnionPacket { + /// BOLT 4 version number. + pub version: u8, /// In order to ensure we always return an error on onion decode in compliance with [BOLT /// #4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md), we have to /// deserialize `OnionPacket`s contained in [`UpdateAddHTLC`] messages even if the ephemeral /// public key (here) is bogus, so we hold a [`Result`] instead of a [`PublicKey`] as we'd /// like. - pub(crate) public_key: Result, - pub(crate) hop_data: [u8; 20*65], - pub(crate) hmac: [u8; 32], + pub public_key: Result, + /// 1300 bytes encrypted payload for the next hop. + pub hop_data: [u8; 20*65], + /// HMAC to verify the integrity of hop_data. + pub hmac: [u8; 32], } impl onion_utils::Packet for OnionPacket { diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs index 9af3de07f..63abdc59b 100644 --- a/lightning/src/ln/onion_utils.rs +++ b/lightning/src/ln/onion_utils.rs @@ -935,6 +935,27 @@ pub(crate) fn decode_next_payment_hop( } } +/// Build a payment onion, returning the first hop msat and cltv values as well. +/// `cur_block_height` should be set to the best known block height + 1. +pub fn create_payment_onion( + secp_ctx: &Secp256k1, path: &Path, session_priv: &SecretKey, total_msat: u64, + recipient_onion: RecipientOnionFields, cur_block_height: u32, payment_hash: &PaymentHash, + keysend_preimage: &Option, prng_seed: [u8; 32] +) -> Result<(msgs::OnionPacket, u64, u32), APIError> { + let onion_keys = construct_onion_keys(&secp_ctx, &path, &session_priv) + .map_err(|_| APIError::InvalidRoute{ + err: "Pubkey along hop was maliciously selected".to_owned() + })?; + let (onion_payloads, htlc_msat, htlc_cltv) = build_onion_payloads( + &path, total_msat, recipient_onion, cur_block_height, keysend_preimage + )?; + let onion_packet = construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash) + .map_err(|_| APIError::InvalidRoute{ + err: "Route size too large considering onion data".to_owned() + })?; + Ok((onion_packet, htlc_msat, htlc_cltv)) +} + pub(crate) fn decode_next_untagged_hop, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> { decode_next_hop(shared_secret, hop_data, hmac_bytes, None, read_args) } -- 2.39.5