Introduce ChannelMonitor::is_paying_spendable_output
authorAntoine Riard <ariard@student.42.fr>
Wed, 18 Mar 2020 20:56:32 +0000 (16:56 -0400)
committerAntoine Riard <ariard@student.42.fr>
Fri, 20 Mar 2020 02:29:26 +0000 (22:29 -0400)
Previously, we would generate SpendableOutputDescriptor::StaticOutput
in OnchainTxHandler even if our claiming transaction wouldn't confirm
onchain, misbehaving user wallet to think it receives more funds than
in reality.

Fix tests in consequence

lightning/src/ln/channelmonitor.rs
lightning/src/ln/functional_tests.rs
lightning/src/ln/onchaintx.rs

index c2dd9c352a32a4885d8204680a70f3819125b028..d714f1e34a052b8ca19c4c72ccd6636a1a55adc0 100644 (file)
@@ -759,6 +759,7 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        latest_update_id: u64,
        commitment_transaction_number_obscure_factor: u64,
 
+       destination_script: Script,
        key_storage: Storage<ChanSigner>,
        their_htlc_base_key: Option<PublicKey>,
        their_delayed_payment_base_key: Option<PublicKey>,
@@ -838,6 +839,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
        fn eq(&self, other: &Self) -> bool {
                if self.latest_update_id != other.latest_update_id ||
                        self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
+                       self.destination_script != other.destination_script ||
                        self.key_storage != other.key_storage ||
                        self.their_htlc_base_key != other.their_htlc_base_key ||
                        self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
@@ -880,6 +882,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                // Set in initial Channel-object creation, so should always be set by now:
                U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
 
+               self.destination_script.write(writer)?;
                match self.key_storage {
                        Storage::Local { ref keys, ref funding_key, ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref funding_info, ref current_remote_commitment_txid, ref prev_remote_commitment_txid } => {
                                writer.write_all(&[0; 1])?;
@@ -1111,6 +1114,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        latest_update_id: 0,
                        commitment_transaction_number_obscure_factor,
 
+                       destination_script: destination_script.clone(),
                        key_storage: Storage::Local {
                                keys,
                                funding_key,
@@ -2076,6 +2080,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        // can also be resolved in a few other ways which can have more than one output. Thus,
                        // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
                        self.is_resolving_htlc_output(&tx, height);
+
+                       if let Some(spendable_output) = self.is_paying_spendable_output(&tx) {
+                               spendable_outputs.push(spendable_output);
+                       }
                }
                let should_broadcast = if let Some(_) = self.current_local_signed_commitment_tx {
                        self.would_broadcast_at_height(height)
@@ -2124,8 +2132,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                }
                        }
                }
-               let mut spendable_output = self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator);
-               spendable_outputs.append(&mut spendable_output);
+               self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator);
 
                self.last_block_hash = block_hash.clone();
                for &(ref txid, ref output_scripts) in watch_outputs.iter() {
@@ -2367,6 +2374,19 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        }
                }
        }
+
+       /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
+       fn is_paying_spendable_output(&self, tx: &Transaction) -> Option<SpendableOutputDescriptor> {
+               for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
+                       if outp.script_pubkey == self.destination_script {
+                               return Some(SpendableOutputDescriptor::StaticOutput {
+                                       outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
+                                       output: outp.clone(),
+                               });
+                       }
+               }
+               None
+       }
 }
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
@@ -2391,6 +2411,8 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dH
                let latest_update_id: u64 = Readable::read(reader)?;
                let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
 
+               let destination_script = Readable::read(reader)?;
+
                let key_storage = match <u8 as Readable>::read(reader)? {
                        0 => {
                                let keys = Readable::read(reader)?;
@@ -2631,6 +2653,8 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dH
                        latest_update_id,
                        commitment_transaction_number_obscure_factor,
 
+                       destination_script,
+
                        key_storage,
                        their_htlc_base_key,
                        their_delayed_payment_base_key,
index e00e036db53478279dcc8abf4e79af660f519d62..392b69e3c112905148877182654dbcda098b10da 100644 (file)
@@ -4100,17 +4100,20 @@ fn test_claim_on_remote_revoked_sizeable_push_msat() {
        assert_eq!(revoked_local_txn[0].input[0].previous_output.txid, chan.3.txid());
 
        claim_payment(&nodes[0], &vec!(&nodes[1])[..], payment_preimage, 3_000_000);
-       let  header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
        nodes[1].block_notifier.block_connected(&Block { header, txdata: vec![revoked_local_txn[0].clone()] }, 1);
        check_closed_broadcast!(nodes[1], false);
        check_added_monitors!(nodes[1], 1);
 
        let node_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap();
+       let header_1 = BlockHeader { version: 0x20000000, prev_blockhash: header.bitcoin_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       nodes[1].block_notifier.block_connected(&Block { header: header_1, txdata: vec![node_txn[0].clone()] }, 2);
+
        let spend_txn = check_spendable_outputs!(nodes[1], 1);
        assert_eq!(spend_txn.len(), 3);
-       assert_eq!(spend_txn[0], spend_txn[2]); // to_remote output on revoked remote commitment_tx
+       assert_eq!(spend_txn[0], spend_txn[1]); // to_remote output on revoked remote commitment_tx
        check_spends!(spend_txn[0], revoked_local_txn[0]);
-       check_spends!(spend_txn[1], node_txn[0]);
+       check_spends!(spend_txn[2], node_txn[0]);
 }
 
 #[test]
@@ -4150,11 +4153,13 @@ fn test_static_spendable_outputs_preimage_tx() {
        assert_eq!(node_txn.len(), 3);
        check_spends!(node_txn[0], commitment_tx[0]);
        assert_eq!(node_txn[0].input[0].witness.last().unwrap().len(), OFFERED_HTLC_SCRIPT_WEIGHT);
-eprintln!("{:?}", node_txn[1]);
        check_spends!(node_txn[1], chan_1.3);
        check_spends!(node_txn[2], node_txn[1]);
 
-       let spend_txn = check_spendable_outputs!(nodes[1], 1); // , 0, 0, 1, 1);
+       let header_1 = BlockHeader { version: 0x20000000, prev_blockhash: header.bitcoin_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       nodes[1].block_notifier.block_connected(&Block { header: header_1, txdata: vec![node_txn[0].clone()] }, 1);
+
+       let spend_txn = check_spendable_outputs!(nodes[1], 1);
        assert_eq!(spend_txn.len(), 1);
        check_spends!(spend_txn[0], node_txn[0]);
 }
@@ -4186,6 +4191,9 @@ fn test_static_spendable_outputs_justice_tx_revoked_commitment_tx() {
        assert_eq!(node_txn[0].input.len(), 2);
        check_spends!(node_txn[0], revoked_local_txn[0]);
 
+       let header_1 = BlockHeader { version: 0x20000000, prev_blockhash: header.bitcoin_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       nodes[1].block_notifier.block_connected(&Block { header: header_1, txdata: vec![node_txn[0].clone()] }, 2);
+
        let spend_txn = check_spendable_outputs!(nodes[1], 1);
        assert_eq!(spend_txn.len(), 1);
        check_spends!(spend_txn[0], node_txn[0]);
@@ -4223,7 +4231,7 @@ fn test_static_spendable_outputs_justice_tx_revoked_htlc_timeout_tx() {
        check_spends!(revoked_htlc_txn[1], chan_1.3);
 
        // B will generate justice tx from A's revoked commitment/HTLC tx
-       nodes[1].block_notifier.block_connected(&Block { header, txdata: vec![revoked_local_txn[0].clone(), revoked_htlc_txn[0].clone()] }, 1);
+       nodes[1].block_notifier.block_connected(&Block { header, txdata: vec![revoked_local_txn[0].clone(), revoked_htlc_txn[0].clone()] }, 0);
        check_closed_broadcast!(nodes[1], false);
        check_added_monitors!(nodes[1], 1);
 
@@ -4237,6 +4245,9 @@ fn test_static_spendable_outputs_justice_tx_revoked_htlc_timeout_tx() {
        assert_eq!(node_txn[3].input.len(), 1);
        check_spends!(node_txn[3], revoked_local_txn[0]);
 
+       let header_1 = BlockHeader { version: 0x20000000, prev_blockhash: header.bitcoin_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       nodes[1].block_notifier.block_connected(&Block { header: header_1, txdata: vec![node_txn[0].clone(), node_txn[2].clone()] }, 1);
+
        // Check B's ChannelMonitor was able to generate the right spendable output descriptor
        let spend_txn = check_spendable_outputs!(nodes[1], 1);
        assert_eq!(spend_txn.len(), 2);
@@ -4284,13 +4295,17 @@ fn test_static_spendable_outputs_justice_tx_revoked_htlc_success_tx() {
        assert_eq!(node_txn[2].input.len(), 1);
        check_spends!(node_txn[2], revoked_htlc_txn[0]);
 
+       let header_1 = BlockHeader { version: 0x20000000, prev_blockhash: header.bitcoin_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       nodes[0].block_notifier.block_connected(&Block { header: header_1, txdata: vec![node_txn[0].clone(), node_txn[2].clone()] }, 1);
+
        // Check A's ChannelMonitor was able to generate the right spendable output descriptor
        let spend_txn = check_spendable_outputs!(nodes[0], 1);
        assert_eq!(spend_txn.len(), 5); // Duplicated SpendableOutput due to block rescan after revoked htlc output tracking
+       assert_eq!(spend_txn[0], spend_txn[1]);
        assert_eq!(spend_txn[0], spend_txn[2]);
        check_spends!(spend_txn[0], revoked_local_txn[0]); // spending to_remote output from revoked local tx
-       check_spends!(spend_txn[1], node_txn[0]); // spending justice tx output from revoked local tx htlc received output
-       check_spends!(spend_txn[3], node_txn[2]); // spending justice tx output on htlc success tx
+       check_spends!(spend_txn[3], node_txn[0]); // spending justice tx output from revoked local tx htlc received output
+       check_spends!(spend_txn[4], node_txn[2]); // spending justice tx output on htlc success tx
 }
 
 #[test]
index 3f21d4c1f64b4a4a73b708c9e924863960384e50..8323a58fb5cb231196d707197ebd389d46cfc2e9 100644 (file)
@@ -17,7 +17,6 @@ use ln::msgs::DecodeError;
 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
 use ln::chan_utils::HTLCType;
 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
-use chain::keysinterface::SpendableOutputDescriptor;
 use util::logger::Logger;
 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
 use util::byte_utils;
@@ -478,7 +477,7 @@ impl OnchainTxHandler {
                Some((new_timer, new_feerate, bumped_tx))
        }
 
-       pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F) -> Vec<SpendableOutputDescriptor>
+       pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F)
                where B::Target: BroadcasterInterface,
                      F::Target: FeeEstimator
        {
@@ -486,7 +485,6 @@ impl OnchainTxHandler {
                let mut new_claims = Vec::new();
                let mut aggregated_claim = HashMap::new();
                let mut aggregated_soonest = ::std::u32::MAX;
-               let mut spendable_outputs = Vec::new();
 
                // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
                // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
@@ -522,10 +520,6 @@ impl OnchainTxHandler {
                                        self.claimable_outpoints.insert(k.clone(), (txid, height));
                                }
                                log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
-                               spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
-                                       outpoint: BitcoinOutPoint { txid: tx.txid(), vout: 0 },
-                                       output: tx.output[0].clone(),
-                               });
                                broadcaster.broadcast_transaction(&tx);
                        }
                }
@@ -656,8 +650,6 @@ impl OnchainTxHandler {
                                } else { unreachable!(); }
                        }
                }
-
-               spendable_outputs
        }
 
        pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)