// our payment, which we can use to decode errors or inform the user that the payment was sent.
#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
-enum PendingHTLCRouting {
+pub(super) enum PendingHTLCRouting {
Forward {
onion_packet: msgs::OnionPacket,
short_channel_id: u64, // This should be NonZero<u64> eventually when we bump MSRV
Receive {
payment_data: msgs::FinalOnionHopData,
incoming_cltv_expiry: u32, // Used to track when we should expire pending HTLCs that go unclaimed
+ phantom_shared_secret: Option<[u8; 32]>,
},
ReceiveKeysend {
payment_preimage: PaymentPreimage,
#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) struct PendingHTLCInfo {
- routing: PendingHTLCRouting,
- incoming_shared_secret: [u8; 32],
+ pub(super) routing: PendingHTLCRouting,
+ pub(super) incoming_shared_secret: [u8; 32],
payment_hash: PaymentHash,
pub(super) amt_to_forward: u64,
pub(super) outgoing_cltv_value: u32,
short_channel_id: u64,
htlc_id: u64,
incoming_packet_shared_secret: [u8; 32],
+ phantom_shared_secret: Option<[u8; 32]>,
// This field is consumed by `claim_funds_from_hop()` when updating a force-closed backwards
// channel with a preimage provided by the forward channel.
}
fn construct_recv_pending_htlc_info(&self, hop_data: msgs::OnionHopData, shared_secret: [u8; 32],
- payment_hash: PaymentHash, amt_msat: u64, cltv_expiry: u32) -> Result<PendingHTLCInfo, ReceiveError>
+ payment_hash: PaymentHash, amt_msat: u64, cltv_expiry: u32, phantom_shared_secret: Option<[u8; 32]>) -> Result<PendingHTLCInfo, ReceiveError>
{
// final_incorrect_cltv_expiry
if hop_data.outgoing_cltv_value != cltv_expiry {
PendingHTLCRouting::Receive {
payment_data: data,
incoming_cltv_expiry: hop_data.outgoing_cltv_value,
+ phantom_shared_secret,
}
} else if let Some(payment_preimage) = keysend_preimage {
// We need to check that the sender knows the keysend preimage before processing this
let pending_forward_info = match next_hop {
onion_utils::Hop::Receive(next_hop_data) => {
// OUR PAYMENT!
- match self.construct_recv_pending_htlc_info(next_hop_data, shared_secret, msg.payment_hash, msg.amount_msat, msg.cltv_expiry) {
+ match self.construct_recv_pending_htlc_info(next_hop_data, shared_secret, msg.payment_hash, msg.amount_msat, msg.cltv_expiry, None) {
Ok(info) => {
// Note that we could obviously respond immediately with an update_fulfill_htlc
// message, however that would leak that we are the recipient of this payment, so
routing, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
prev_funding_outpoint } => {
macro_rules! fail_forward {
- ($msg: expr, $err_code: expr, $err_data: expr) => {
+ ($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr) => {
{
log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);
let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
- short_channel_id: short_chan_id,
+ short_channel_id: prev_short_channel_id,
outpoint: prev_funding_outpoint,
htlc_id: prev_htlc_id,
incoming_packet_shared_secret: incoming_shared_secret,
+ phantom_shared_secret: $phantom_ss,
});
failed_forwards.push((htlc_source, payment_hash,
- HTLCFailReason::Reason { failure_code: $err_code, data: $err_data }
+ HTLCFailReason::Reason { failure_code: $err_code, data: $err_data }
));
continue;
}
if let PendingHTLCRouting::Forward { onion_packet, .. } = routing {
let phantom_secret_res = self.keys_manager.get_node_secret(Recipient::PhantomNode);
if phantom_secret_res.is_ok() && fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, short_chan_id) {
- let shared_secret = {
+ let phantom_shared_secret = {
let mut arr = [0; 32];
arr.copy_from_slice(&SharedSecret::new(&onion_packet.public_key.unwrap(), &phantom_secret_res.unwrap())[..]);
arr
};
- let next_hop = match onion_utils::decode_next_hop(shared_secret, &onion_packet.hop_data, onion_packet.hmac, payment_hash) {
+ let next_hop = match onion_utils::decode_next_hop(phantom_shared_secret, &onion_packet.hop_data, onion_packet.hmac, payment_hash) {
Ok(res) => res,
Err(onion_utils::OnionDecodeErr::Malformed { err_msg, err_code }) => {
- fail_forward!(err_msg, err_code, Vec::new());
+ let sha256_of_onion = Sha256::hash(&onion_packet.hop_data).into_inner();
+ // In this scenario, the phantom would have sent us an
+ // `update_fail_malformed_htlc`, meaning here we encrypt the error as
+ // if it came from us (the second-to-last hop) but contains the sha256
+ // of the onion.
+ fail_forward!(err_msg, err_code, sha256_of_onion.to_vec(), None);
},
Err(onion_utils::OnionDecodeErr::Relay { err_msg, err_code }) => {
- fail_forward!(err_msg, err_code, Vec::new());
+ fail_forward!(err_msg, err_code, Vec::new(), Some(phantom_shared_secret));
},
};
match next_hop {
onion_utils::Hop::Receive(hop_data) => {
- match self.construct_recv_pending_htlc_info(hop_data, shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value) {
+ match self.construct_recv_pending_htlc_info(hop_data, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value, Some(phantom_shared_secret)) {
Ok(info) => phantom_receives.push((prev_short_channel_id, prev_funding_outpoint, vec![(info, prev_htlc_id)])),
- Err(ReceiveError { err_code, err_data, msg }) => fail_forward!(msg, err_code, err_data)
+ Err(ReceiveError { err_code, err_data, msg }) => fail_forward!(msg, err_code, err_data, Some(phantom_shared_secret))
}
},
_ => panic!(),
}
} else {
- fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new());
+ fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new(), None);
}
} else {
- fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new());
+ fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new(), None);
}
},
HTLCForwardInfo::FailHTLC { .. } => {
// the channel is now on chain and our counterparty is
// trying to broadcast the HTLC-Timeout, but that's their
// problem, not ours.
- //
- // `fail_htlc_backwards_internal` is never called for
- // phantom payments, so this is unreachable for them.
}
}
}
outpoint: prev_funding_outpoint,
htlc_id: prev_htlc_id,
incoming_packet_shared_secret: incoming_shared_secret,
+ // Phantom payments are only PendingHTLCRouting::Receive.
+ phantom_shared_secret: None,
});
match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet, &self.logger) {
Err(e) => {
HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
routing, incoming_shared_secret, payment_hash, amt_to_forward, .. },
prev_funding_outpoint } => {
- let (cltv_expiry, onion_payload) = match routing {
- PendingHTLCRouting::Receive { payment_data, incoming_cltv_expiry } =>
- (incoming_cltv_expiry, OnionPayload::Invoice(payment_data)),
+ let (cltv_expiry, onion_payload, phantom_shared_secret) = match routing {
+ PendingHTLCRouting::Receive { payment_data, incoming_cltv_expiry, phantom_shared_secret } =>
+ (incoming_cltv_expiry, OnionPayload::Invoice(payment_data), phantom_shared_secret),
PendingHTLCRouting::ReceiveKeysend { payment_preimage, incoming_cltv_expiry } =>
- (incoming_cltv_expiry, OnionPayload::Spontaneous(payment_preimage)),
+ (incoming_cltv_expiry, OnionPayload::Spontaneous(payment_preimage), None),
_ => {
panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
}
outpoint: prev_funding_outpoint,
htlc_id: prev_htlc_id,
incoming_packet_shared_secret: incoming_shared_secret,
+ phantom_shared_secret,
},
value: amt_to_forward,
cltv_expiry,
outpoint: prev_funding_outpoint,
htlc_id: $htlc.prev_hop.htlc_id,
incoming_packet_shared_secret: $htlc.prev_hop.incoming_packet_shared_secret,
+ phantom_shared_secret,
}), payment_hash,
HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data }
));
pending_events.push(path_failure);
if let Some(ev) = full_failure_ev { pending_events.push(ev); }
},
- HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, incoming_packet_shared_secret, .. }) => {
+ HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, incoming_packet_shared_secret, phantom_shared_secret, .. }) => {
let err_packet = match onion_error {
HTLCFailReason::Reason { failure_code, data } => {
log_trace!(self.logger, "Failing HTLC with payment_hash {} backwards from us with code {}", log_bytes!(payment_hash.0), failure_code);
- let packet = onion_utils::build_failure_packet(&incoming_packet_shared_secret, failure_code, &data[..]).encode();
- onion_utils::encrypt_failure_packet(&incoming_packet_shared_secret, &packet)
+ if let Some(phantom_ss) = phantom_shared_secret {
+ let phantom_packet = onion_utils::build_failure_packet(&phantom_ss, failure_code, &data[..]).encode();
+ let encrypted_phantom_packet = onion_utils::encrypt_failure_packet(&phantom_ss, &phantom_packet);
+ onion_utils::encrypt_failure_packet(&incoming_packet_shared_secret, &encrypted_phantom_packet.data[..])
+ } else {
+ let packet = onion_utils::build_failure_packet(&incoming_packet_shared_secret, failure_code, &data[..]).encode();
+ onion_utils::encrypt_failure_packet(&incoming_packet_shared_secret, &packet)
+ }
},
HTLCFailReason::LightningError { err } => {
log_trace!(self.logger, "Failing HTLC with payment_hash {} backwards with pre-built LightningError", log_bytes!(payment_hash.0));
onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{
let mut res = Vec::with_capacity(8 + 128);
// TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
- res.extend_from_slice(&byte_utils::be16_to_array(0));
+ if error_code == 0x1000 | 20 {
+ res.extend_from_slice(&byte_utils::be16_to_array(0));
+ }
res.extend_from_slice(&upd.encode_with_len()[..]);
res
}[..])
},
(1, Receive) => {
(0, payment_data, required),
+ (1, phantom_shared_secret, option),
(2, incoming_cltv_expiry, required),
},
(2, ReceiveKeysend) => {
impl_writeable_tlv_based!(HTLCPreviousHopData, {
(0, short_channel_id, required),
+ (1, phantom_shared_secret, option),
(2, outpoint, required),
(4, htlc_id, required),
(6, incoming_packet_shared_secret, required)