Skip to content

Pre-refactor for HTLC Interception #1840

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Nov 9, 2022
Merged

Pre-refactor for HTLC Interception #1840

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
582b827
Refactor HTLCForwardInfo::AddHTLC for intercept forwards
valentinewallace Nov 4, 2022
b3d257d
Delete unnecessary whitespace in process_pending_forwards
valentinewallace Nov 4, 2022
203394f
Track incoming amount in PendingHTLCInfo
valentinewallace Nov 4, 2022
c793549
Fix scid_utils::is_valid* false positive
valentinewallace Nov 7, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
221 changes: 119 additions & 102 deletions lightning/src/ln/channelmanager.rs
View file
Open in desktop
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),
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

In a followup, lets rename this incoming_amt_msat and the following to_forward_amt_msat or just some ther names with msat in them.

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
Open in desktop
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
Loading