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Merged
merged 8 commits into from
Mar 6, 2025
Merged

Parse inbound Trampoline onions #3620

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8025e33
Remove some trailing spaces
arik-so Feb 26, 2025
56caad8
Create blinded `TrampolineEntrypoint` variant
arik-so Feb 27, 2025
ee1514a
Use Hop instead of InboundOnionPayload
arik-so Feb 24, 2025
a11e66d
Parse inbound TrampolineEntrypoint payload
arik-so Feb 24, 2025
164c166
Parse Trampoline onion payloads
arik-so Mar 2, 2025
9fd40cd
Expand utility of secondary shared secrets
arik-so Feb 26, 2025
72ce1d2
Introduce HopConnector enum
arik-so Feb 3, 2025
1fd69ee
Decrypt Trampoline onions
arik-so Feb 27, 2025
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108 changes: 50 additions & 58 deletions lightning/src/ln/channelmanager.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4466,38 +4466,24 @@ where
}
match decoded_hop {
onion_utils::Hop::Receive { .. } | onion_utils::Hop::BlindedReceive { .. } => {
let inbound_onion_payload = match decoded_hop {
onion_utils::Hop::Receive { hop_data, .. } => msgs::InboundOnionPayload::Receive(hop_data),
onion_utils::Hop::BlindedReceive { hop_data, .. } => msgs::InboundOnionPayload::BlindedReceive(hop_data),
_ => unreachable!()
};

// OUR PAYMENT!
let current_height: u32 = self.best_block.read().unwrap().height;
match create_recv_pending_htlc_info(inbound_onion_payload, shared_secret, msg.payment_hash,
match create_recv_pending_htlc_info(decoded_hop, shared_secret, msg.payment_hash,
msg.amount_msat, msg.cltv_expiry, None, allow_underpay, msg.skimmed_fee_msat,
current_height)
{
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
// instead we stay symmetric with the forwarding case, only responding (after a
// delay) once they've send us a commitment_signed!
// delay) once they've sent us a commitment_signed!
PendingHTLCStatus::Forward(info)
},
Err(InboundHTLCErr { err_code, err_data, msg }) => return_err!(msg, err_code, &err_data)
}
},
onion_utils::Hop::Forward { next_hop_data, next_hop_hmac, new_packet_bytes, .. } => {
match create_fwd_pending_htlc_info(msg, msgs::InboundOnionPayload::Forward(next_hop_data), next_hop_hmac,
new_packet_bytes, shared_secret, next_packet_pubkey_opt) {
Ok(info) => PendingHTLCStatus::Forward(info),
Err(InboundHTLCErr { err_code, err_data, msg }) => return_err!(msg, err_code, &err_data)
}
},
onion_utils::Hop::BlindedForward { next_hop_data, next_hop_hmac, new_packet_bytes, .. } => {
match create_fwd_pending_htlc_info(msg, msgs::InboundOnionPayload::BlindedForward(next_hop_data), next_hop_hmac,
new_packet_bytes, shared_secret, next_packet_pubkey_opt) {
onion_utils::Hop::Forward { .. } | onion_utils::Hop::BlindedForward { .. } => {
match create_fwd_pending_htlc_info(msg, decoded_hop, shared_secret, next_packet_pubkey_opt) {
Ok(info) => PendingHTLCStatus::Forward(info),
Err(InboundHTLCErr { err_code, err_data, msg }) => return_err!(msg, err_code, &err_data)
}
Expand Down Expand Up @@ -5912,14 +5898,9 @@ where
failed_payment!(err_msg, err_code, Vec::new(), Some(phantom_shared_secret));
},
};
let (inbound_onion_payload, shared_secret) = match next_hop {
onion_utils::Hop::Receive { hop_data, shared_secret } => (msgs::InboundOnionPayload::Receive(hop_data), shared_secret),
onion_utils::Hop::BlindedReceive { hop_data, shared_secret } => (msgs::InboundOnionPayload::BlindedReceive(hop_data), shared_secret),
_ => panic!()
};
let phantom_shared_secret = shared_secret.secret_bytes();
let phantom_shared_secret = next_hop.shared_secret().secret_bytes();
let current_height: u32 = self.best_block.read().unwrap().height;
match create_recv_pending_htlc_info(inbound_onion_payload,
match create_recv_pending_htlc_info(next_hop,
incoming_shared_secret, payment_hash, outgoing_amt_msat,
outgoing_cltv_value, Some(phantom_shared_secret), false, None,
current_height)
Expand Down Expand Up @@ -14847,13 +14828,15 @@ where
mod tests {
use bitcoin::hashes::Hash;
use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
use bitcoin::secp256k1::ecdh::SharedSecret;
use core::sync::atomic::Ordering;
use crate::events::{Event, HTLCDestination, ClosureReason};
use crate::ln::types::ChannelId;
use crate::types::payment::{PaymentPreimage, PaymentHash, PaymentSecret};
use crate::ln::channelmanager::{create_recv_pending_htlc_info, inbound_payment, ChannelConfigOverrides, HTLCForwardInfo, InterceptId, PaymentId, RecipientOnionFields};
use crate::ln::functional_test_utils::*;
use crate::ln::msgs::{self, BaseMessageHandler, ChannelMessageHandler, AcceptChannel, ErrorAction, MessageSendEvent};
use crate::ln::onion_utils;
use crate::ln::outbound_payment::Retry;
use crate::prelude::*;
use crate::routing::router::{PaymentParameters, RouteParameters, find_route};
Expand Down Expand Up @@ -15944,17 +15927,20 @@ mod tests {
let node = create_network(1, &node_cfg, &node_chanmgr);
let sender_intended_amt_msat = 100;
let extra_fee_msat = 10;
let hop_data = msgs::InboundOnionPayload::Receive(msgs::InboundOnionReceivePayload {
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: 42,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: sender_intended_amt_msat,
}),
custom_tlvs: Vec::new(),
});
let hop_data = onion_utils::Hop::Receive {
hop_data: msgs::InboundOnionReceivePayload {
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: 42,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: sender_intended_amt_msat,
}),
custom_tlvs: Vec::new(),
},
shared_secret: SharedSecret::from_bytes([0; 32]),
};
// Check that if the amount we received + the penultimate hop extra fee is less than the sender
// intended amount, we fail the payment.
let current_height: u32 = node[0].node.best_block.read().unwrap().height;
Expand All @@ -15967,17 +15953,20 @@ mod tests {
} else { panic!(); }

// If amt_received + extra_fee is equal to the sender intended amount, we're fine.
let hop_data = msgs::InboundOnionPayload::Receive(msgs::InboundOnionReceivePayload { // This is the same payload as above, InboundOnionPayload doesn't implement Clone
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: 42,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: sender_intended_amt_msat,
}),
custom_tlvs: Vec::new(),
});
let hop_data = onion_utils::Hop::Receive {
hop_data: msgs::InboundOnionReceivePayload { // This is the same payload as above, InboundOnionPayload doesn't implement Clone
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: 42,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: sender_intended_amt_msat,
}),
custom_tlvs: Vec::new(),
},
shared_secret: SharedSecret::from_bytes([0; 32]),
};
let current_height: u32 = node[0].node.best_block.read().unwrap().height;
assert!(create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
sender_intended_amt_msat - extra_fee_msat, 42, None, true, Some(extra_fee_msat),
Expand All @@ -15992,17 +15981,20 @@ mod tests {
let node = create_network(1, &node_cfg, &node_chanmgr);

let current_height: u32 = node[0].node.best_block.read().unwrap().height;
let result = create_recv_pending_htlc_info(msgs::InboundOnionPayload::Receive(msgs::InboundOnionReceivePayload {
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: TEST_FINAL_CLTV,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: 100,
}),
custom_tlvs: Vec::new(),
}), [0; 32], PaymentHash([0; 32]), 100, TEST_FINAL_CLTV + 1, None, true, None, current_height);
let result = create_recv_pending_htlc_info(onion_utils::Hop::Receive {
hop_data: msgs::InboundOnionReceivePayload {
sender_intended_htlc_amt_msat: 100,
cltv_expiry_height: TEST_FINAL_CLTV,
payment_metadata: None,
keysend_preimage: None,
payment_data: Some(msgs::FinalOnionHopData {
payment_secret: PaymentSecret([0; 32]),
total_msat: 100,
}),
custom_tlvs: Vec::new(),
},
shared_secret: SharedSecret::from_bytes([0; 32]),
}, [0; 32], PaymentHash([0; 32]), 100, TEST_FINAL_CLTV + 1, None, true, None, current_height);

// Should not return an error as this condition:
// https://github.com/lightning/bolts/blob/4dcc377209509b13cf89a4b91fde7d478f5b46d8/04-onion-routing.md?plain=1#L334
Expand Down
80 changes: 34 additions & 46 deletions lightning/src/ln/onion_payment.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ use crate::ln::channelmanager::{BlindedFailure, BlindedForward, CLTV_FAR_FAR_AWA
use crate::types::features::BlindedHopFeatures;
use crate::ln::msgs;
use crate::ln::onion_utils;
use crate::ln::onion_utils::{Hop, HTLCFailReason, INVALID_ONION_BLINDING};
use crate::ln::onion_utils::{HTLCFailReason, INVALID_ONION_BLINDING};
use crate::sign::{NodeSigner, Recipient};
use crate::util::logger::Logger;

Expand Down Expand Up @@ -61,28 +61,23 @@ fn check_blinded_forward(
}

pub(super) fn create_fwd_pending_htlc_info(
msg: &msgs::UpdateAddHTLC, hop_data: msgs::InboundOnionPayload, hop_hmac: [u8; 32],
new_packet_bytes: [u8; onion_utils::ONION_DATA_LEN], shared_secret: [u8; 32],
msg: &msgs::UpdateAddHTLC, hop_data: onion_utils::Hop, shared_secret: [u8; 32],
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@TheBlueMatt TheBlueMatt Mar 6, 2025

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Maybe in a followup we drop the shared_secret argument given that Hop::Forward already has it?

next_packet_pubkey_opt: Option<Result<PublicKey, secp256k1::Error>>
) -> Result<PendingHTLCInfo, InboundHTLCErr> {
debug_assert!(next_packet_pubkey_opt.is_some());
let outgoing_packet = msgs::OnionPacket {
version: 0,
public_key: next_packet_pubkey_opt.unwrap_or(Err(secp256k1::Error::InvalidPublicKey)),
hop_data: new_packet_bytes,
hmac: hop_hmac,
};

let (
short_channel_id, amt_to_forward, outgoing_cltv_value, intro_node_blinding_point,
next_blinding_override
next_blinding_override, new_packet_bytes, next_hop_hmac
) = match hop_data {
msgs::InboundOnionPayload::Forward(msgs::InboundOnionForwardPayload { short_channel_id, amt_to_forward, outgoing_cltv_value }) =>
(short_channel_id, amt_to_forward, outgoing_cltv_value, None, None),
msgs::InboundOnionPayload::BlindedForward(msgs::InboundOnionBlindedForwardPayload {
onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionForwardPayload {
short_channel_id, amt_to_forward, outgoing_cltv_value
}, new_packet_bytes, next_hop_hmac, .. } =>
(short_channel_id, amt_to_forward, outgoing_cltv_value, None, None, new_packet_bytes, next_hop_hmac),
onion_utils::Hop::BlindedForward { next_hop_data: msgs::InboundOnionBlindedForwardPayload {
short_channel_id, payment_relay, payment_constraints, intro_node_blinding_point, features,
next_blinding_override,
}) => {
}, new_packet_bytes, next_hop_hmac, .. } => {
let (amt_to_forward, outgoing_cltv_value) = check_blinded_forward(
msg.amount_msat, msg.cltv_expiry, &payment_relay, &payment_constraints, &features
).map_err(|()| {
Expand All @@ -95,16 +90,23 @@ pub(super) fn create_fwd_pending_htlc_info(
}
})?;
(short_channel_id, amt_to_forward, outgoing_cltv_value, intro_node_blinding_point,
next_blinding_override)
next_blinding_override, new_packet_bytes, next_hop_hmac)
},
msgs::InboundOnionPayload::Receive { .. } | msgs::InboundOnionPayload::BlindedReceive { .. } =>
onion_utils::Hop::Receive { .. } | onion_utils::Hop::BlindedReceive { .. } =>
return Err(InboundHTLCErr {
msg: "Final Node OnionHopData provided for us as an intermediary node",
err_code: 0x4000 | 22,
err_data: Vec::new(),
}),
};

let outgoing_packet = msgs::OnionPacket {
version: 0,
public_key: next_packet_pubkey_opt.unwrap_or(Err(secp256k1::Error::InvalidPublicKey)),
hop_data: new_packet_bytes,
hmac: next_hop_hmac,
};

Ok(PendingHTLCInfo {
routing: PendingHTLCRouting::Forward {
onion_packet: outgoing_packet,
Expand All @@ -129,7 +131,7 @@ pub(super) fn create_fwd_pending_htlc_info(
}

pub(super) fn create_recv_pending_htlc_info(
hop_data: msgs::InboundOnionPayload, shared_secret: [u8; 32], payment_hash: PaymentHash,
hop_data: onion_utils::Hop, shared_secret: [u8; 32], payment_hash: PaymentHash,
amt_msat: u64, cltv_expiry: u32, phantom_shared_secret: Option<[u8; 32]>, allow_underpay: bool,
counterparty_skimmed_fee_msat: Option<u64>, current_height: u32
) -> Result<PendingHTLCInfo, InboundHTLCErr> {
Expand All @@ -138,17 +140,17 @@ pub(super) fn create_recv_pending_htlc_info(
payment_metadata, payment_context, requires_blinded_error, has_recipient_created_payment_secret,
invoice_request
) = match hop_data {
msgs::InboundOnionPayload::Receive(msgs::InboundOnionReceivePayload {
onion_utils::Hop::Receive { hop_data: msgs::InboundOnionReceivePayload {
payment_data, keysend_preimage, custom_tlvs, sender_intended_htlc_amt_msat,
cltv_expiry_height, payment_metadata, ..
}) =>
}, .. } =>
(payment_data, keysend_preimage, custom_tlvs, sender_intended_htlc_amt_msat,
cltv_expiry_height, payment_metadata, None, false, keysend_preimage.is_none(), None),
msgs::InboundOnionPayload::BlindedReceive(msgs::InboundOnionBlindedReceivePayload {
onion_utils::Hop::BlindedReceive { hop_data: msgs::InboundOnionBlindedReceivePayload {
sender_intended_htlc_amt_msat, total_msat, cltv_expiry_height, payment_secret,
intro_node_blinding_point, payment_constraints, payment_context, keysend_preimage,
custom_tlvs, invoice_request
}) => {
}, .. } => {
check_blinded_payment_constraints(
sender_intended_htlc_amt_msat, cltv_expiry, &payment_constraints
)
Expand All @@ -164,20 +166,20 @@ pub(super) fn create_recv_pending_htlc_info(
sender_intended_htlc_amt_msat, cltv_expiry_height, None, Some(payment_context),
intro_node_blinding_point.is_none(), true, invoice_request)
}
msgs::InboundOnionPayload::Forward { .. } => {
onion_utils::Hop::Forward { .. } => {
return Err(InboundHTLCErr {
err_code: 0x4000|22,
err_data: Vec::new(),
msg: "Got non final data with an HMAC of 0",
})
},
msgs::InboundOnionPayload::BlindedForward { .. } => {
onion_utils::Hop::BlindedForward { .. } => {
return Err(InboundHTLCErr {
err_code: INVALID_ONION_BLINDING,
err_data: vec![0; 32],
msg: "Got blinded non final data with an HMAC of 0",
})
}
},
};
// final_incorrect_cltv_expiry
if onion_cltv_expiry > cltv_expiry {
Expand Down Expand Up @@ -295,14 +297,8 @@ where
InboundHTLCErr { msg, err_code, err_data }
})?;
Ok(match hop {
onion_utils::Hop::Forward { shared_secret, next_hop_hmac, new_packet_bytes, .. } |
onion_utils::Hop::BlindedForward { shared_secret, next_hop_hmac, new_packet_bytes, .. } => {
let inbound_onion_payload = match hop {
onion_utils::Hop::Forward { next_hop_data, .. } => msgs::InboundOnionPayload::Forward(next_hop_data),
onion_utils::Hop::BlindedForward { next_hop_data, .. } => msgs::InboundOnionPayload::BlindedForward(next_hop_data),
_ => unreachable!()
};

onion_utils::Hop::Forward { shared_secret, .. } |
onion_utils::Hop::BlindedForward { shared_secret, .. } => {
let NextPacketDetails {
next_packet_pubkey, outgoing_amt_msat: _, outgoing_scid: _, outgoing_cltv_value
} = match next_packet_details_opt {
Expand All @@ -327,20 +323,12 @@ where

// 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, inbound_onion_payload, next_hop_hmac, new_packet_bytes, shared_secret.secret_bytes(),
Some(next_packet_pubkey),
)?
},
onion_utils::Hop::Receive { hop_data, shared_secret } => {
create_recv_pending_htlc_info(
msgs::InboundOnionPayload::Receive(hop_data), shared_secret.secret_bytes(), msg.payment_hash, msg.amount_msat, msg.cltv_expiry,
None, allow_skimmed_fees, msg.skimmed_fee_msat, cur_height,
)?
create_fwd_pending_htlc_info(msg, hop, shared_secret.secret_bytes(), Some(next_packet_pubkey))?
},
onion_utils::Hop::BlindedReceive { hop_data, shared_secret } => {
_ => {
let shared_secret = hop.shared_secret().secret_bytes();
create_recv_pending_htlc_info(
msgs::InboundOnionPayload::BlindedReceive(hop_data), shared_secret.secret_bytes(), msg.payment_hash, msg.amount_msat, msg.cltv_expiry,
hop, shared_secret, msg.payment_hash, msg.amount_msat, msg.cltv_expiry,
None, allow_skimmed_fees, msg.skimmed_fee_msat, cur_height,
)?
}
Expand Down Expand Up @@ -422,15 +410,15 @@ where
};

let next_packet_details = match next_hop {
Hop::Forward { next_hop_data: msgs::InboundOnionForwardPayload { short_channel_id, amt_to_forward, outgoing_cltv_value }, shared_secret, .. } => {
onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionForwardPayload { short_channel_id, amt_to_forward, outgoing_cltv_value }, shared_secret, .. } => {
let next_packet_pubkey = onion_utils::next_hop_pubkey(secp_ctx,
msg.onion_routing_packet.public_key.unwrap(), &shared_secret.secret_bytes());
Some(NextPacketDetails {
next_packet_pubkey, outgoing_scid: short_channel_id,
outgoing_amt_msat: amt_to_forward, outgoing_cltv_value
})
}
Hop::BlindedForward { next_hop_data: msgs::InboundOnionBlindedForwardPayload { short_channel_id, ref payment_relay, ref payment_constraints, ref features, .. }, shared_secret, .. } => {
onion_utils::Hop::BlindedForward { next_hop_data: msgs::InboundOnionBlindedForwardPayload { short_channel_id, ref payment_relay, ref payment_constraints, ref features, .. }, shared_secret, .. } => {
let (amt_to_forward, outgoing_cltv_value) = match check_blinded_forward(
msg.amount_msat, msg.cltv_expiry, &payment_relay, &payment_constraints, &features
) {
Expand Down