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Merge pull request #1840 from valentinewallace/2022-11-htlc-intercept…
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…-prefactor

Pre-refactor for HTLC Interception
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@TheBlueMatt
TheBlueMatt authored Nov 9, 2022
2 parents 30b9807 + c793549 commit d036400
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221 changes: 119 additions & 102 deletions lightning/src/ln/channelmanager.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,7 @@ pub(super) struct PendingHTLCInfo {
pub(super) incoming_shared_secret: [u8; 32],
payment_hash: PaymentHash,
pub(super) amt_to_forward: u64,
pub(super) amt_incoming: Option<u64>, // Added in 0.0.113
pub(super) outgoing_cltv_value: u32,
}

Expand All @@ -129,20 +130,22 @@ pub(super) enum PendingHTLCStatus {
Fail(HTLCFailureMsg),
}

pub(super) enum HTLCForwardInfo {
AddHTLC {
forward_info: PendingHTLCInfo,
pub(super) struct PendingAddHTLCInfo {
pub(super) forward_info: PendingHTLCInfo,

// These fields are produced in `forward_htlcs()` and consumed in
// `process_pending_htlc_forwards()` for constructing the
// `HTLCSource::PreviousHopData` for failed and forwarded
// HTLCs.
//
// Note that this may be an outbound SCID alias for the associated channel.
prev_short_channel_id: u64,
prev_htlc_id: u64,
prev_funding_outpoint: OutPoint,
},
// These fields are produced in `forward_htlcs()` and consumed in
// `process_pending_htlc_forwards()` for constructing the
// `HTLCSource::PreviousHopData` for failed and forwarded
// HTLCs.
//
// Note that this may be an outbound SCID alias for the associated channel.
prev_short_channel_id: u64,
prev_htlc_id: u64,
prev_funding_outpoint: OutPoint,
}

pub(super) enum HTLCForwardInfo {
AddHTLC(PendingAddHTLCInfo),
FailHTLC {
htlc_id: u64,
err_packet: msgs::OnionErrorPacket,
Expand Down Expand Up @@ -2194,6 +2197,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
routing,
payment_hash,
incoming_shared_secret: shared_secret,
amt_incoming: Some(amt_msat),
amt_to_forward: amt_msat,
outgoing_cltv_value: hop_data.outgoing_cltv_value,
})
Expand Down Expand Up @@ -2290,6 +2294,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
},
payment_hash: msg.payment_hash.clone(),
incoming_shared_secret: shared_secret,
amt_incoming: Some(msg.amount_msat),
amt_to_forward: next_hop_data.amt_to_forward,
outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
})
Expand All @@ -2308,7 +2313,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
None => { // unknown_next_peer
// Note that this is likely a timing oracle for detecting whether an scid is a
// phantom.
if fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id) {
if fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash) {
None
} else {
break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None));
Expand Down Expand Up @@ -3149,82 +3154,86 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
() => {
for forward_info in pending_forwards.drain(..) {
match forward_info {
HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
routing, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
prev_funding_outpoint } => {
macro_rules! failure_handler {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr, $next_hop_unknown: expr) => {
log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);

let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
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,
});

let reason = if $next_hop_unknown {
HTLCDestination::UnknownNextHop { requested_forward_scid: short_chan_id }
} else {
HTLCDestination::FailedPayment{ payment_hash }
};

failed_forwards.push((htlc_source, payment_hash,
HTLCFailReason::Reason { failure_code: $err_code, data: $err_data },
reason
));
continue;
}
HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_htlc_id, prev_funding_outpoint,
forward_info: PendingHTLCInfo {
routing, incoming_shared_secret, payment_hash, amt_to_forward,
outgoing_cltv_value, amt_incoming: _
}
}) => {
macro_rules! failure_handler {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr, $next_hop_unknown: expr) => {
log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);

let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
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,
});

let reason = if $next_hop_unknown {
HTLCDestination::UnknownNextHop { requested_forward_scid: short_chan_id }
} else {
HTLCDestination::FailedPayment{ payment_hash }
};

failed_forwards.push((htlc_source, payment_hash,
HTLCFailReason::Reason { failure_code: $err_code, data: $err_data },
reason
));
continue;
}
macro_rules! fail_forward {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr) => {
{
failure_handler!($msg, $err_code, $err_data, $phantom_ss, true);
}
}
macro_rules! fail_forward {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr) => {
{
failure_handler!($msg, $err_code, $err_data, $phantom_ss, true);
}
}
macro_rules! failed_payment {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr) => {
{
failure_handler!($msg, $err_code, $err_data, $phantom_ss, false);
}
}
macro_rules! failed_payment {
($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr) => {
{
failure_handler!($msg, $err_code, $err_data, $phantom_ss, false);
}
}
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 phantom_shared_secret = SharedSecret::new(&onion_packet.public_key.unwrap(), &phantom_secret_res.unwrap()).secret_bytes();
let next_hop = match onion_utils::decode_next_payment_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 }) => {
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.
failed_payment!(err_msg, err_code, sha256_of_onion.to_vec(), None);
},
Err(onion_utils::OnionDecodeErr::Relay { err_msg, err_code }) => {
failed_payment!(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, 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 }) => failed_payment!(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(), None);
}
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, &self.genesis_hash) {
let phantom_shared_secret = SharedSecret::new(&onion_packet.public_key.unwrap(), &phantom_secret_res.unwrap()).secret_bytes();
let next_hop = match onion_utils::decode_next_payment_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 }) => {
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.
failed_payment!(err_msg, err_code, sha256_of_onion.to_vec(), None);
},
Err(onion_utils::OnionDecodeErr::Relay { err_msg, err_code }) => {
failed_payment!(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, 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 }) => failed_payment!(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(), None);
}
},
} else {
fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new(), None);
}
},
HTLCForwardInfo::FailHTLC { .. } => {
// Channel went away before we could fail it. This implies
// the channel is now on chain and our counterparty is
Expand Down Expand Up @@ -3252,11 +3261,13 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
let mut fail_htlc_msgs = Vec::new();
for forward_info in pending_forwards.drain(..) {
match forward_info {
HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
routing: PendingHTLCRouting::Forward {
onion_packet, ..
}, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
prev_funding_outpoint } => {
HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_htlc_id, prev_funding_outpoint ,
forward_info: PendingHTLCInfo {
incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value,
routing: PendingHTLCRouting::Forward { onion_packet, .. }, amt_incoming: _,
},
}) => {
log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id);
let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
short_channel_id: prev_short_channel_id,
Expand Down Expand Up @@ -3377,9 +3388,12 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
} else {
for forward_info in pending_forwards.drain(..) {
match forward_info {
HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
routing, incoming_shared_secret, payment_hash, amt_to_forward, .. },
prev_funding_outpoint } => {
HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_htlc_id, prev_funding_outpoint,
forward_info: PendingHTLCInfo {
routing, incoming_shared_secret, payment_hash, amt_to_forward, ..
}
}) => {
let (cltv_expiry, onion_payload, payment_data, phantom_shared_secret) = match routing {
PendingHTLCRouting::Receive { payment_data, incoming_cltv_expiry, phantom_shared_secret } => {
let _legacy_hop_data = Some(payment_data.clone());
Expand Down Expand Up @@ -5089,12 +5103,12 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
PendingHTLCRouting::ReceiveKeysend { .. } => 0,
}) {
hash_map::Entry::Occupied(mut entry) => {
entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_funding_outpoint,
prev_htlc_id, forward_info });
entry.get_mut().push(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, forward_info }));
},
hash_map::Entry::Vacant(entry) => {
entry.insert(vec!(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_funding_outpoint,
prev_htlc_id, forward_info }));
entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, forward_info })));
}
}
}
Expand Down Expand Up @@ -6459,7 +6473,8 @@ impl_writeable_tlv_based!(PendingHTLCInfo, {
(2, incoming_shared_secret, required),
(4, payment_hash, required),
(6, amt_to_forward, required),
(8, outgoing_cltv_value, required)
(8, outgoing_cltv_value, required),
(9, amt_incoming, option),
});


Expand Down Expand Up @@ -6681,18 +6696,20 @@ impl_writeable_tlv_based_enum!(HTLCFailReason,
},
;);

impl_writeable_tlv_based!(PendingAddHTLCInfo, {
(0, forward_info, required),
(2, prev_short_channel_id, required),
(4, prev_htlc_id, required),
(6, prev_funding_outpoint, required),
});

impl_writeable_tlv_based_enum!(HTLCForwardInfo,
(0, AddHTLC) => {
(0, forward_info, required),
(2, prev_short_channel_id, required),
(4, prev_htlc_id, required),
(6, prev_funding_outpoint, required),
},
(1, FailHTLC) => {
(0, htlc_id, required),
(2, err_packet, required),
},
;);
};
(0, AddHTLC)
);

impl_writeable_tlv_based!(PendingInboundPayment, {
(0, payment_secret, required),
Expand Down
18 changes: 9 additions & 9 deletions lightning/src/ln/onion_route_tests.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ use crate::chain::channelmonitor::{ChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GR
use crate::chain::keysinterface::{KeysInterface, Recipient};
use crate::ln::{PaymentHash, PaymentSecret};
use crate::ln::channel::EXPIRE_PREV_CONFIG_TICKS;
use crate::ln::channelmanager::{self, ChannelManager, ChannelManagerReadArgs, HTLCForwardInfo, CLTV_FAR_FAR_AWAY, MIN_CLTV_EXPIRY_DELTA, PendingHTLCInfo, PendingHTLCRouting, PaymentId};
use crate::ln::channelmanager::{self, ChannelManager, ChannelManagerReadArgs, HTLCForwardInfo, CLTV_FAR_FAR_AWAY, MIN_CLTV_EXPIRY_DELTA, PendingAddHTLCInfo, PendingHTLCInfo, PendingHTLCRouting, PaymentId};
use crate::ln::onion_utils;
use crate::routing::gossip::{NetworkUpdate, RoutingFees, NodeId};
use crate::routing::router::{get_route, PaymentParameters, Route, RouteHint, RouteHintHop};
Expand Down Expand Up @@ -554,7 +554,7 @@ fn test_onion_failure() {
for (_, pending_forwards) in nodes[1].node.forward_htlcs.lock().unwrap().iter_mut() {
for f in pending_forwards.iter_mut() {
match f {
&mut HTLCForwardInfo::AddHTLC { ref mut forward_info, .. } =>
&mut HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { ref mut forward_info, .. }) =>
forward_info.outgoing_cltv_value += 1,
_ => {},
}
Expand All @@ -567,7 +567,7 @@ fn test_onion_failure() {
for (_, pending_forwards) in nodes[1].node.forward_htlcs.lock().unwrap().iter_mut() {
for f in pending_forwards.iter_mut() {
match f {
&mut HTLCForwardInfo::AddHTLC { ref mut forward_info, .. } =>
&mut HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { ref mut forward_info, .. }) =>
forward_info.amt_to_forward -= 1,
_ => {},
}
Expand Down Expand Up @@ -1035,12 +1035,12 @@ fn test_phantom_onion_hmac_failure() {
let mut forward_htlcs = nodes[1].node.forward_htlcs.lock().unwrap();
let mut pending_forward = forward_htlcs.get_mut(&phantom_scid).unwrap();
match pending_forward[0] {
HTLCForwardInfo::AddHTLC {
HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
forward_info: PendingHTLCInfo {
routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
..
}, ..
} => {
}) => {
onion_packet.hmac[onion_packet.hmac.len() - 1] ^= 1;
Sha256::hash(&onion_packet.hop_data).into_inner().to_vec()
},
Expand Down Expand Up @@ -1095,12 +1095,12 @@ fn test_phantom_invalid_onion_payload() {
for (_, pending_forwards) in nodes[1].node.forward_htlcs.lock().unwrap().iter_mut() {
for f in pending_forwards.iter_mut() {
match f {
&mut HTLCForwardInfo::AddHTLC {
&mut HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
forward_info: PendingHTLCInfo {
routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
..
}, ..
} => {
}) => {
// Construct the onion payloads for the entire route and an invalid amount.
let height = nodes[0].best_block_info().1;
let session_priv = SecretKey::from_slice(&session_priv).unwrap();
Expand Down Expand Up @@ -1166,9 +1166,9 @@ fn test_phantom_final_incorrect_cltv_expiry() {
for (_, pending_forwards) in nodes[1].node.forward_htlcs.lock().unwrap().iter_mut() {
for f in pending_forwards.iter_mut() {
match f {
&mut HTLCForwardInfo::AddHTLC {
&mut HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
forward_info: PendingHTLCInfo { ref mut outgoing_cltv_value, .. }, ..
} => {
}) => {
*outgoing_cltv_value += 1;
},
_ => panic!("Unexpected forward"),
Expand Down
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