-//! Utilities for channelmanager.rs
+//! Utilities to decode payment onions and do contextless validation of incoming payments.
//!
-//! Includes a public [`peel_payment_onion`] function for use by external projects or libraries.
+//! Primarily features [`peel_payment_onion`], which allows the decoding of an onion statelessly
+//! and can be used to predict whether we'd accept a payment.
use bitcoin::hashes::Hash;
use bitcoin::hashes::sha256::Hash as Sha256;
use core::ops::Deref;
/// Invalid inbound onion payment.
+#[derive(Debug)]
pub struct InboundOnionErr {
/// BOLT 4 error code.
pub err_code: u16,
})
}
-/// Peel one layer off an incoming onion, returning [`PendingHTLCInfo`] (either Forward or Receive).
+/// Peel one layer off an incoming onion, returning a [`PendingHTLCInfo`] that contains information
+/// about the intended next-hop for the HTLC.
+///
/// This does all the relevant context-free checks that LDK requires for payment relay or
/// acceptance. If the payment is to be received, and the amount matches the expected amount for
/// a given invoice, this indicates the [`msgs::UpdateAddHTLC`], once fully committed in the
/// [`Event::PaymentClaimable`]: crate::events::Event::PaymentClaimable
pub fn peel_payment_onion<NS: Deref, L: Deref, T: secp256k1::Verification>(
msg: &msgs::UpdateAddHTLC, node_signer: &NS, logger: &L, secp_ctx: &Secp256k1<T>,
- cur_height: u32, accept_mpp_keysend: bool,
+ cur_height: u32, accept_mpp_keysend: bool, allow_skimmed_fees: bool,
) -> Result<PendingHTLCInfo, InboundOnionErr>
where
NS::Target: NodeSigner,
err_data: Vec::new(),
});
}
+
+ // TODO: If this is potentially a phantom payment we should decode the phantom payment
+ // onion here and check it.
+
create_fwd_pending_htlc_info(
msg, next_hop_data, next_hop_hmac, new_packet_bytes, shared_secret,
Some(next_packet_pubkey)
onion_utils::Hop::Receive(received_data) => {
create_recv_pending_htlc_info(
received_data, shared_secret, msg.payment_hash, msg.amount_msat, msg.cltv_expiry,
- None, false, msg.skimmed_fee_msat, cur_height, accept_mpp_keysend,
+ None, allow_skimmed_fees, msg.skimmed_fee_msat, cur_height, accept_mpp_keysend,
)?
}
})
mod tests {
use bitcoin::hashes::Hash;
use bitcoin::hashes::sha256::Hash as Sha256;
- use bitcoin::secp256k1::{PublicKey, SecretKey};
+ use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
use crate::ln::ChannelId;
use crate::ln::channelmanager::RecipientOnionFields;
use crate::routing::router::{Path, RouteHop};
use crate::util::test_utils;
+ #[test]
+ fn fail_construct_onion_on_too_big_payloads() {
+ // Ensure that if we call `construct_onion_packet` and friends where payloads are too large for
+ // the allotted packet length, we'll fail to construct. Previously, senders would happily
+ // construct invalid packets by array-shifting the final node's HMAC out of the packet when
+ // adding an intermediate onion layer, causing the receiver to error with "final payload
+ // provided for us as an intermediate node."
+ let secp_ctx = Secp256k1::new();
+ let bob = crate::sign::KeysManager::new(&[2; 32], 42, 42);
+ let bob_pk = PublicKey::from_secret_key(&secp_ctx, &bob.get_node_secret_key());
+ let charlie = crate::sign::KeysManager::new(&[3; 32], 42, 42);
+ let charlie_pk = PublicKey::from_secret_key(&secp_ctx, &charlie.get_node_secret_key());
+
+ let (
+ session_priv, total_amt_msat, cur_height, mut recipient_onion, keysend_preimage, payment_hash,
+ prng_seed, hops, ..
+ ) = payment_onion_args(bob_pk, charlie_pk);
+
+ // Ensure the onion will not fit all the payloads by adding a large custom TLV.
+ recipient_onion.custom_tlvs.push((13377331, vec![0; 1156]));
+
+ let path = Path { hops, blinded_tail: None, };
+ let onion_keys = super::onion_utils::construct_onion_keys(&secp_ctx, &path, &session_priv).unwrap();
+ let (onion_payloads, ..) = super::onion_utils::build_onion_payloads(
+ &path, total_amt_msat, recipient_onion, cur_height + 1, &Some(keysend_preimage)
+ ).unwrap();
+
+ assert!(super::onion_utils::construct_onion_packet(
+ onion_payloads, onion_keys, prng_seed, &payment_hash
+ ).is_err());
+ }
+
#[test]
fn test_peel_payment_onion() {
use super::*;
let msg = make_update_add_msg(amount_msat, cltv_expiry, payment_hash, onion);
let logger = test_utils::TestLogger::with_id("bob".to_string());
- let peeled = peel_payment_onion(&msg, &&bob, &&logger, &secp_ctx, cur_height, true)
+ let peeled = peel_payment_onion(&msg, &&bob, &&logger, &secp_ctx, cur_height, true, false)
.map_err(|e| e.msg).unwrap();
let next_onion = match peeled.routing {
};
let msg2 = make_update_add_msg(amount_msat, cltv_expiry, payment_hash, next_onion);
- let peeled2 = peel_payment_onion(&msg2, &&charlie, &&logger, &secp_ctx, cur_height, true)
+ let peeled2 = peel_payment_onion(&msg2, &&charlie, &&logger, &secp_ctx, cur_height, true, false)
.map_err(|e| e.msg).unwrap();
match peeled2.routing {