Correctly fail back phantom node payments that don't match inbound payment data

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index e6fc17da428c567fc7d0fbe8c9294346943c6aab..e8aee263ae606be9af8ac6e06ab8f5ec13dddcca 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -366,6 +366,7 @@ pub(super) enum PendingHTLCRouting {
        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,
@@ -2072,7 +2073,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        }
 
        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 {
@@ -2129,6 +2130,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        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
@@ -2232,7 +2234,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                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
@@ -3061,7 +3063,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                                                        };
                                                                                                        match next_hop {
                                                                                                                onion_utils::Hop::Receive(hop_data) => {
-                                                                                                                       match self.construct_recv_pending_htlc_info(hop_data, phantom_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_phantom_forward!(msg, err_code, err_data, phantom_shared_secret)
                                                                                                                        }
@@ -3221,11 +3223,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                        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");
                                                                        }
@@ -3248,13 +3250,20 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                                htlc_msat_height_data.extend_from_slice(
                                                                                        &byte_utils::be32_to_array(self.best_block.read().unwrap().height()),
                                                                                );
+                                                                               let failure_code = 0x4000 | 15;
+                                                                               let failure_reason = if let Some(phantom_ss) = phantom_shared_secret {
+                                                                                       let packet = onion_utils::build_failure_packet(&phantom_ss, failure_code, &htlc_msat_height_data[..]).encode();
+                                                                                       let error_data =  onion_utils::encrypt_failure_packet(&phantom_ss, &packet);
+                                                                                       HTLCFailReason::LightningError { err: error_data }
+                                                                               } else {
+                                                                                       HTLCFailReason::Reason { failure_code, data: htlc_msat_height_data }
+                                                                               };
                                                                                failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                                short_channel_id: $htlc.prev_hop.short_channel_id,
                                                                                                outpoint: prev_funding_outpoint,
                                                                                                htlc_id: $htlc.prev_hop.htlc_id,
                                                                                                incoming_packet_shared_secret: $htlc.prev_hop.incoming_packet_shared_secret,
-                                                                                       }), payment_hash,
-                                                                                       HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data }
+                                                                                       }), payment_hash, failure_reason
                                                                                ));
                                                                        }
                                                                }
@@ -5993,6 +6002,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
        },
        (1, Receive) => {
                (0, payment_data, required),
+               (1, phantom_shared_secret, option),
                (2, incoming_cltv_expiry, required),
        },
        (2, ReceiveKeysend) => {