Add in-flight claim-tx tracking
authorAntoine Riard <ariard@student.42.fr>
Sun, 31 Mar 2019 02:12:55 +0000 (22:12 -0400)
committerAntoine Riard <ariard@student.42.fr>
Fri, 19 Jul 2019 21:21:00 +0000 (17:21 -0400)
When we generate a justice tx, a htlc tx on remote commitment or
a htlc tx on local commitment we track them until first conf.

src/ln/channelmonitor.rs

index 6e1b212ea24c051edaa9f8f9eb4dca4380b3a389..f6d741afa10abfecfc64706ab13d6e2ae8a0bfed 100644 (file)
@@ -364,6 +364,32 @@ enum InputDescriptors {
        RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 }
 
+/// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
+/// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
+/// a new bumped one in case of lenghty confirmation delay
+#[derive(Clone, PartialEq)]
+enum TxMaterial {
+       Revoked {
+               script: Script,
+               pubkey: Option<PublicKey>,
+               key: SecretKey,
+               is_htlc: bool,
+               amount: u64,
+       },
+       RemoteHTLC {
+               script: Script,
+               key: SecretKey,
+               preimage: Option<PaymentPreimage>,
+               amount: u64,
+       },
+       LocalHTLC {
+               script: Script,
+               sigs: (Signature, Signature),
+               preimage: Option<PaymentPreimage>,
+               amount: u64,
+       }
+}
+
 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
 #[derive(Clone, PartialEq)]
@@ -431,6 +457,12 @@ pub struct ChannelMonitor {
 
        destination_script: Script,
 
+       // Used to track outpoint in the process of being claimed by our transactions. We need to scan all transactions
+       // for inputs spending this. If height timer (u32) is expired and claim tx hasn't reached enough confirmations
+       // before, use TxMaterial to regenerate a new claim tx with a satoshis-per-1000-weight-units higher than last
+       // one (u64).
+       our_claim_txn_waiting_first_conf: HashMap<BitcoinOutPoint, (u32, TxMaterial, u64)>,
+
        // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
        // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
        // actions when we receive a block with given height. Actions depend on OnchainEvent type.
@@ -447,13 +479,16 @@ pub struct ChannelMonitor {
 }
 
 macro_rules! subtract_high_prio_fee {
-       ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $spent_txid: expr) => {
+       ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $spent_txid: expr, $used_feerate: expr) => {
                {
-                       let mut fee = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * $predicted_weight / 1000;
+                       $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
+                       let mut fee = $used_feerate * $predicted_weight / 1000;
                        if $value <= fee {
-                               fee = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal) * $predicted_weight / 1000;
+                               $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
+                               fee = $used_feerate * $predicted_weight / 1000;
                                if $value <= fee {
-                                       fee = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background) * $predicted_weight / 1000;
+                                       $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
+                                       fee = $used_feerate * $predicted_weight / 1000;
                                        if $value <= fee {
                                                log_error!($self, "Failed to generate an on-chain punishment tx spending {} as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
                                                        $spent_txid, fee, $value);
@@ -498,6 +533,7 @@ impl PartialEq for ChannelMonitor {
                        self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
                        self.payment_preimages != other.payment_preimages ||
                        self.destination_script != other.destination_script ||
+                       self.our_claim_txn_waiting_first_conf != other.our_claim_txn_waiting_first_conf ||
                        self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf
                {
                        false
@@ -548,6 +584,8 @@ impl ChannelMonitor {
                        payment_preimages: HashMap::new(),
                        destination_script: destination_script,
 
+                       our_claim_txn_waiting_first_conf: HashMap::new(),
+
                        onchain_events_waiting_threshold_conf: HashMap::new(),
 
                        last_block_hash: Default::default(),
@@ -1057,6 +1095,42 @@ impl ChannelMonitor {
                self.last_block_hash.write(writer)?;
                self.destination_script.write(writer)?;
 
+               writer.write_all(&byte_utils::be64_to_array(self.our_claim_txn_waiting_first_conf.len() as u64))?;
+               for (ref outpoint, claim_tx_data) in self.our_claim_txn_waiting_first_conf.iter() {
+                       outpoint.write(writer)?;
+                       writer.write_all(&byte_utils::be32_to_array(claim_tx_data.0))?;
+                       match claim_tx_data.1 {
+                               TxMaterial::Revoked { ref script, ref pubkey, ref key, ref is_htlc, ref amount} => {
+                                       writer.write_all(&[0; 1])?;
+                                       script.write(writer)?;
+                                       pubkey.write(writer)?;
+                                       writer.write_all(&key[..])?;
+                                       if *is_htlc {
+                                               writer.write_all(&[0; 1])?;
+                                       } else {
+                                               writer.write_all(&[1; 1])?;
+                                       }
+                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                               },
+                               TxMaterial::RemoteHTLC { ref script, ref key, ref preimage, ref amount } => {
+                                       writer.write_all(&[1; 1])?;
+                                       script.write(writer)?;
+                                       key.write(writer)?;
+                                       preimage.write(writer)?;
+                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                               },
+                               TxMaterial::LocalHTLC { ref script, ref sigs, ref preimage, ref amount } => {
+                                       writer.write_all(&[2; 1])?;
+                                       script.write(writer)?;
+                                       sigs.0.write(writer)?;
+                                       sigs.1.write(writer)?;
+                                       preimage.write(writer)?;
+                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                               }
+                       }
+                       writer.write_all(&byte_utils::be64_to_array(claim_tx_data.2))?;
+               }
+
                writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
                for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
                        writer.write_all(&byte_utils::be32_to_array(**target))?;
@@ -1193,10 +1267,9 @@ impl ChannelMonitor {
                        } else { None };
 
                        let mut total_value = 0;
-                       let mut values = Vec::new();
                        let mut inputs = Vec::new();
-                       let mut htlc_idxs = Vec::new();
-                       let mut input_descriptors = Vec::new();
+                       let mut inputs_info = Vec::new();
+                       let mut inputs_desc = Vec::new();
 
                        for (idx, outp) in tx.output.iter().enumerate() {
                                if outp.script_pubkey == revokeable_p2wsh {
@@ -1209,10 +1282,9 @@ impl ChannelMonitor {
                                                sequence: 0xfffffffd,
                                                witness: Vec::new(),
                                        });
-                                       htlc_idxs.push(None);
-                                       values.push(outp.value);
+                                       inputs_desc.push(InputDescriptors::RevokedOutput);
+                                       inputs_info.push((None, outp.value));
                                        total_value += outp.value;
-                                       input_descriptors.push(InputDescriptors::RevokedOutput);
                                } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() {
                                        spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
                                                outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
@@ -1225,7 +1297,7 @@ impl ChannelMonitor {
                        macro_rules! sign_input {
                                ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
                                        {
-                                               let (sig, redeemscript) = match self.key_storage {
+                                               let (sig, redeemscript, revocation_key) = match self.key_storage {
                                                        Storage::Local { ref revocation_base_key, .. } => {
                                                                let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
                                                                        let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()].0;
@@ -1233,7 +1305,7 @@ impl ChannelMonitor {
                                                                };
                                                                let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
                                                                let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
-                                                               (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
+                                                               (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript, revocation_key)
                                                        },
                                                        Storage::Watchtower { .. } => {
                                                                unimplemented!();
@@ -1246,7 +1318,8 @@ impl ChannelMonitor {
                                                } else {
                                                        $input.witness.push(revocation_pubkey.serialize().to_vec());
                                                }
-                                               $input.witness.push(redeemscript.into_bytes());
+                                               $input.witness.push(redeemscript.clone().into_bytes());
+                                               (redeemscript, revocation_key)
                                        }
                                }
                        }
@@ -1273,10 +1346,9 @@ impl ChannelMonitor {
                                                };
                                                if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
                                                        inputs.push(input);
-                                                       htlc_idxs.push(Some(idx));
-                                                       values.push(tx.output[transaction_output_index as usize].value);
-                                                       total_value += htlc.amount_msat / 1000;
-                                                       input_descriptors.push(if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC });
+                                                       inputs_desc.push(if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC });
+                                                       inputs_info.push((Some(idx), tx.output[transaction_output_index as usize].value));
+                                                       total_value += tx.output[transaction_output_index as usize].value;
                                                } else {
                                                        let mut single_htlc_tx = Transaction {
                                                                version: 2,
@@ -1288,10 +1360,15 @@ impl ChannelMonitor {
                                                                }),
                                                        };
                                                        let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }]);
-                                                       if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid()) {
+                                                       let mut used_feerate;
+                                                       if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
                                                                let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
-                                                               sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
+                                                               let (redeemscript, revocation_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
                                                                assert!(predicted_weight >= single_htlc_tx.get_weight());
+                                                               match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
+                                                                       hash_map::Entry::Occupied(_) => {},
+                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                               }
                                                                txn_to_broadcast.push(single_htlc_tx);
                                                        }
                                                }
@@ -1355,18 +1432,22 @@ impl ChannelMonitor {
                                input: inputs,
                                output: outputs,
                        };
-                       let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..]);
 
-                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid()) {
+                       let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&inputs_desc[..]);
+
+                       let mut used_feerate;
+                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
                                return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs);
                        }
 
-                       let mut values_drain = values.drain(..);
                        let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 
-                       for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
-                               let value = values_drain.next().unwrap();
-                               sign_input!(sighash_parts, input, htlc_idx, value);
+                       for (input, info) in spend_tx.input.iter_mut().zip(inputs_info.iter()) {
+                               let (redeemscript, revocation_key) = sign_input!(sighash_parts, input, info.0, info.1);
+                               match self.our_claim_txn_waiting_first_conf.entry(input.previous_output.clone()) {
+                                       hash_map::Entry::Occupied(_) => {},
+                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: if info.0.is_some() { Some(revocation_pubkey) } else { None }, key: revocation_key, is_htlc: if info.0.is_some() { true } else { false }, amount: info.1 }, used_feerate)); }
+                               }
                        }
                        assert!(predicted_weight >= spend_tx.get_weight());
 
@@ -1480,20 +1561,20 @@ impl ChannelMonitor {
                                        }
 
                                        let mut total_value = 0;
-                                       let mut values = Vec::new();
                                        let mut inputs = Vec::new();
-                                       let mut input_descriptors = Vec::new();
+                                       let mut inputs_desc = Vec::new();
+                                       let mut inputs_info = Vec::new();
 
                                        macro_rules! sign_input {
                                                ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
                                                        {
-                                                               let (sig, redeemscript) = match self.key_storage {
+                                                               let (sig, redeemscript, htlc_key) = match self.key_storage {
                                                                        Storage::Local { ref htlc_base_key, .. } => {
                                                                                let htlc = &per_commitment_option.unwrap()[$input.sequence as usize].0;
                                                                                let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                                                                let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
                                                                                let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
-                                                                               (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
+                                                                               (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript, htlc_key)
                                                                        },
                                                                        Storage::Watchtower { .. } => {
                                                                                unimplemented!();
@@ -1502,7 +1583,8 @@ impl ChannelMonitor {
                                                                $input.witness.push(sig.serialize_der().to_vec());
                                                                $input.witness[0].push(SigHashType::All as u8);
                                                                $input.witness.push($preimage);
-                                                               $input.witness.push(redeemscript.into_bytes());
+                                                               $input.witness.push(redeemscript.clone().into_bytes());
+                                                               (redeemscript, htlc_key)
                                                        }
                                                }
                                        }
@@ -1527,9 +1609,9 @@ impl ChannelMonitor {
                                                                };
                                                                if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
                                                                        inputs.push(input);
-                                                                       values.push((tx.output[transaction_output_index as usize].value, payment_preimage));
-                                                                       total_value += htlc.amount_msat / 1000;
-                                                                       input_descriptors.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
+                                                                       inputs_desc.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
+                                                                       inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value));
+                                                                       total_value += tx.output[transaction_output_index as usize].value;
                                                                } else {
                                                                        let mut single_htlc_tx = Transaction {
                                                                                version: 2,
@@ -1541,14 +1623,19 @@ impl ChannelMonitor {
                                                                                }),
                                                                        };
                                                                        let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }]);
-                                                                       if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid()) {
+                                                                       let mut used_feerate;
+                                                                       if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
                                                                                let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
-                                                                               sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
+                                                                               let (redeemscript, htlc_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
                                                                                assert!(predicted_weight >= single_htlc_tx.get_weight());
                                                                                spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
                                                                                        outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
                                                                                        output: single_htlc_tx.output[0].clone(),
                                                                                });
+                                                                               match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
+                                                                                       hash_map::Entry::Occupied(_) => {},
+                                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                                               }
                                                                                txn_to_broadcast.push(single_htlc_tx);
                                                                        }
                                                                }
@@ -1574,8 +1661,18 @@ impl ChannelMonitor {
                                                                                value: htlc.amount_msat / 1000,
                                                                        }),
                                                                };
-                                                               let sighash_parts = bip143::SighashComponents::new(&timeout_tx);
-                                                               sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]);
+                                                               let predicted_weight = timeout_tx.get_weight() + Self::get_witnesses_weight(&[InputDescriptors::ReceivedHTLC]);
+                                                               let mut used_feerate;
+                                                               if subtract_high_prio_fee!(self, fee_estimator, timeout_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
+                                                                       let sighash_parts = bip143::SighashComponents::new(&timeout_tx);
+                                                                       let (redeemscript, htlc_key) = sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]);
+                                                                       assert!(predicted_weight >= timeout_tx.get_weight());
+                                                                       //TODO: track SpendableOutputDescriptor
+                                                                       match self.our_claim_txn_waiting_first_conf.entry(timeout_tx.input[0].previous_output.clone()) {
+                                                                               hash_map::Entry::Occupied(_) => {},
+                                                                               hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script : redeemscript, key: htlc_key, preimage: None, amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                                       }
+                                                               }
                                                                txn_to_broadcast.push(timeout_tx);
                                                        }
                                                }
@@ -1593,19 +1690,23 @@ impl ChannelMonitor {
                                                input: inputs,
                                                output: outputs,
                                        };
-                                       let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..]);
-                                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid()) {
+
+                                       let mut predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&inputs_desc[..]);
+
+                                       let mut used_feerate;
+                                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
                                                return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs);
                                        }
 
-                                       let mut values_drain = values.drain(..);
                                        let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 
-                                       for input in spend_tx.input.iter_mut() {
-                                               let value = values_drain.next().unwrap();
-                                               sign_input!(sighash_parts, input, value.0, (value.1).0.to_vec());
+                                       for (input, info) in spend_tx.input.iter_mut().zip(inputs_info.iter()) {
+                                               let (redeemscript, htlc_key) = sign_input!(sighash_parts, input, info.1, (info.0).0.to_vec());
+                                               match self.our_claim_txn_waiting_first_conf.entry(input.previous_output.clone()) {
+                                                       hash_map::Entry::Occupied(_) => {},
+                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1}, used_feerate)); }
+                                               }
                                        }
-
                                        assert!(predicted_weight >= spend_tx.get_weight());
                                        spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
                                                outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
@@ -1620,7 +1721,7 @@ impl ChannelMonitor {
        }
 
        /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
-       fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64, fee_estimator: &FeeEstimator) -> (Option<Transaction>, Option<SpendableOutputDescriptor>) {
+       fn check_spend_remote_htlc(&mut self, tx: &Transaction, commitment_number: u64, height: u32, fee_estimator: &FeeEstimator) -> (Option<Transaction>, Option<SpendableOutputDescriptor>) {
                if tx.input.len() != 1 || tx.output.len() != 1 {
                        return (None, None)
                }
@@ -1682,17 +1783,18 @@ impl ChannelMonitor {
                                output: outputs,
                        };
                        let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&[InputDescriptors::RevokedOutput]);
-                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid()) {
+                       let mut used_feerate;
+                       if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) {
                                return (None, None);
                        }
 
                        let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 
-                       let sig = match self.key_storage {
+                       let (sig, revocation_key) = match self.key_storage {
                                Storage::Local { ref revocation_base_key, .. } => {
                                        let sighash = hash_to_message!(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]);
                                        let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
-                                       self.secp_ctx.sign(&sighash, &revocation_key)
+                                       (self.secp_ctx.sign(&sighash, &revocation_key), revocation_key)
                                }
                                Storage::Watchtower { .. } => {
                                        unimplemented!();
@@ -1701,19 +1803,24 @@ impl ChannelMonitor {
                        spend_tx.input[0].witness.push(sig.serialize_der().to_vec());
                        spend_tx.input[0].witness[0].push(SigHashType::All as u8);
                        spend_tx.input[0].witness.push(vec!(1));
-                       spend_tx.input[0].witness.push(redeemscript.into_bytes());
+                       spend_tx.input[0].witness.push(redeemscript.clone().into_bytes());
 
                        assert!(predicted_weight >= spend_tx.get_weight());
                        let outpoint = BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 };
                        let output = spend_tx.output[0].clone();
+                       match self.our_claim_txn_waiting_first_conf.entry(spend_tx.input[0].previous_output.clone()) {
+                               hash_map::Entry::Occupied(_) => {},
+                               hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: None, key: revocation_key, is_htlc: false, amount: tx.output[0].value }, used_feerate)); }
+                       }
                        (Some(spend_tx), Some(SpendableOutputDescriptor::StaticOutput { outpoint, output }))
                } else { (None, None) }
        }
 
-       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>) {
+       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>, height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>, Vec<(BitcoinOutPoint, (u32, TxMaterial, u64))>) {
                let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
                let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
                let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
+               let mut pending_claims = Vec::with_capacity(local_tx.htlc_outputs.len());
 
                macro_rules! add_dynamic_output {
                        ($father_tx: expr, $vout: expr) => {
@@ -1758,9 +1865,11 @@ impl ChannelMonitor {
                                                htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
 
                                                htlc_timeout_tx.input[0].witness.push(Vec::new());
-                                               htlc_timeout_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
+                                               let htlc_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key);
+                                               htlc_timeout_tx.input[0].witness.push(htlc_script.clone().into_bytes());
 
                                                add_dynamic_output!(htlc_timeout_tx, 0);
+                                               pending_claims.push((htlc_timeout_tx.input[0].previous_output.clone(), (height + 3, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: None, amount: htlc.amount_msat / 1000}, 0)));
                                                res.push(htlc_timeout_tx);
                                        } else {
                                                if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1775,9 +1884,11 @@ impl ChannelMonitor {
                                                        htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
 
                                                        htlc_success_tx.input[0].witness.push(payment_preimage.0.to_vec());
-                                                       htlc_success_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
+                                                       let htlc_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key);
+                                                       htlc_success_tx.input[0].witness.push(htlc_script.clone().into_bytes());
 
                                                        add_dynamic_output!(htlc_success_tx, 0);
+                                                       pending_claims.push((htlc_success_tx.input[0].previous_output.clone(), (height + 3, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000}, 0)));
                                                        res.push(htlc_success_tx);
                                                }
                                        }
@@ -1786,7 +1897,7 @@ impl ChannelMonitor {
                        }
                }
 
-               (res, spendable_outputs, watch_outputs)
+               (res, spendable_outputs, watch_outputs, pending_claims)
        }
 
        /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
@@ -1826,6 +1937,12 @@ impl ChannelMonitor {
                                local_txn.append(&mut $updates.0);
                                spendable_outputs.append(&mut $updates.1);
                                watch_outputs.append(&mut $updates.2);
+                               for claim in $updates.3 {
+                                       match self.our_claim_txn_waiting_first_conf.entry(claim.0) {
+                                               hash_map::Entry::Occupied(_) => {},
+                                               hash_map::Entry::Vacant(entry) => { entry.insert(claim.1); }
+                                       }
+                               }
                        }
                }
 
@@ -1838,10 +1955,10 @@ impl ChannelMonitor {
                                log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
-                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key)));
+                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key), height));
                                        },
                                        Storage::Watchtower { .. } => {
-                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, &None, &None));
+                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, &None, &None, height));
                                        }
                                }
                        }
@@ -1852,10 +1969,10 @@ impl ChannelMonitor {
                                log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
-                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)));
+                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key), height));
                                        },
                                        Storage::Watchtower { .. } => {
-                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, &None, &None));
+                                               append_onchain_update!(self.broadcast_by_local_state(local_tx, &None, &None, height));
                                        }
                                }
                        }
@@ -1917,7 +2034,9 @@ impl ChannelMonitor {
                        let mut res = vec![local_tx.tx.clone()];
                        match self.key_storage {
                                Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
-                                       res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)).0);
+                                       res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key), 0).0);
+                                       // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
+                                       // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
                                },
                                _ => panic!("Can only broadcast by local channelmonitor"),
                        };
@@ -1969,7 +2088,7 @@ impl ChannelMonitor {
                                        }
                                } else {
                                        if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
-                                               let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number, fee_estimator);
+                                               let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number, height, fee_estimator);
                                                if let Some(tx) = tx {
                                                        txn.push(tx);
                                                }
@@ -1989,14 +2108,37 @@ impl ChannelMonitor {
                        if updated.len() > 0 {
                                htlc_updated.append(&mut updated);
                        }
+                       for inp in &tx.input {
+                               if self.our_claim_txn_waiting_first_conf.contains_key(&inp.previous_output) {
+                                       match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
+                                               hash_map::Entry::Occupied(mut entry) => {
+                                                       let e = entry.get_mut();
+                                                       e.retain(|ref event| {
+                                                               match **event {
+                                                                       OnchainEvent::Claim { outpoint } => {
+                                                                               return outpoint != inp.previous_output
+                                                                       },
+                                                                       _ => return true
+                                                               }
+                                                       });
+                                                       e.push(OnchainEvent::Claim { outpoint: inp.previous_output.clone()});
+                                               }
+                                               hash_map::Entry::Vacant(entry) => {
+                                                       entry.insert(vec![OnchainEvent::Claim { outpoint: inp.previous_output.clone()}]);
+                                               }
+                                       }
+                               }
+                       }
                }
+               let mut pending_claims = Vec::new();
                if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
                        if self.would_broadcast_at_height(height) {
                                broadcaster.broadcast_transaction(&cur_local_tx.tx);
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
-                                               let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               let (txs, mut spendable_output, new_outputs, mut pending_txn) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key), height);
                                                spendable_outputs.append(&mut spendable_output);
+                                               pending_claims.append(&mut pending_txn);
                                                if !new_outputs.is_empty() {
                                                        watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
                                                }
@@ -2005,8 +2147,9 @@ impl ChannelMonitor {
                                                }
                                        },
                                        Storage::Watchtower { .. } => {
-                                               let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
+                                               let (txs, mut spendable_output, new_outputs, mut pending_txn) = self.broadcast_by_local_state(&cur_local_tx, &None, &None, height);
                                                spendable_outputs.append(&mut spendable_output);
+                                               pending_claims.append(&mut pending_txn);
                                                if !new_outputs.is_empty() {
                                                        watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
                                                }
@@ -2017,10 +2160,17 @@ impl ChannelMonitor {
                                }
                        }
                }
+               for claim in pending_claims {
+                       match self.our_claim_txn_waiting_first_conf.entry(claim.0) {
+                               hash_map::Entry::Occupied(_) => {},
+                               hash_map::Entry::Vacant(entry) => { entry.insert(claim.1); }
+                       }
+               }
                if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
                        for ev in events {
                                match ev {
-                                       OnchainEvent::Claim { outpoint: _ } => {
+                                       OnchainEvent::Claim { outpoint } => {
+                                               self.our_claim_txn_waiting_first_conf.remove(&outpoint);
                                        },
                                        OnchainEvent::HTLCUpdate { htlc_update } => {
                                                log_trace!(self, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
@@ -2029,6 +2179,7 @@ impl ChannelMonitor {
                                }
                        }
                }
+               //TODO: iter on buffered TxMaterial in our_claim_txn_waiting_first_conf, if block timer is expired generate a bumped claim tx (RBF or CPFP accordingly)
                self.last_block_hash = block_hash.clone();
                (watch_outputs, spendable_outputs, htlc_updated)
        }
@@ -2039,6 +2190,7 @@ impl ChannelMonitor {
                        //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
                        //- our claim tx on a commitment tx output
                }
+               self.our_claim_txn_waiting_first_conf.retain(|_, ref mut v| if v.0 == height + 3 { false } else { true });
                self.last_block_hash = block_hash.clone();
        }
 
@@ -2455,6 +2607,61 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                let last_block_hash: Sha256dHash = Readable::read(reader)?;
                let destination_script = Readable::read(reader)?;
 
+               let our_claim_txn_waiting_first_conf_len: u64 = Readable::read(reader)?;
+               let mut our_claim_txn_waiting_first_conf = HashMap::with_capacity(cmp::min(our_claim_txn_waiting_first_conf_len as usize, MAX_ALLOC_SIZE / 128));
+               for _ in 0..our_claim_txn_waiting_first_conf_len {
+                       let outpoint = Readable::read(reader)?;
+                       let height_target = Readable::read(reader)?;
+                       let tx_material = match <u8 as Readable<R>>::read(reader)? {
+                               0 => {
+                                       let script = Readable::read(reader)?;
+                                       let pubkey = Readable::read(reader)?;
+                                       let key = Readable::read(reader)?;
+                                       let is_htlc = match <u8 as Readable<R>>::read(reader)? {
+                                               0 => true,
+                                               1 => false,
+                                               _ => return Err(DecodeError::InvalidValue),
+                                       };
+                                       let amount = Readable::read(reader)?;
+                                       TxMaterial::Revoked {
+                                               script,
+                                               pubkey,
+                                               key,
+                                               is_htlc,
+                                               amount
+                                       }
+                               },
+                               1 => {
+                                       let script = Readable::read(reader)?;
+                                       let key = Readable::read(reader)?;
+                                       let preimage = Readable::read(reader)?;
+                                       let amount = Readable::read(reader)?;
+                                       TxMaterial::RemoteHTLC {
+                                               script,
+                                               key,
+                                               preimage,
+                                               amount
+                                       }
+                               },
+                               2 => {
+                                       let script = Readable::read(reader)?;
+                                       let their_sig = Readable::read(reader)?;
+                                       let our_sig = Readable::read(reader)?;
+                                       let preimage = Readable::read(reader)?;
+                                       let amount = Readable::read(reader)?;
+                                       TxMaterial::LocalHTLC {
+                                               script,
+                                               sigs: (their_sig, our_sig),
+                                               preimage,
+                                               amount
+                                       }
+                               }
+                               _ => return Err(DecodeError::InvalidValue),
+                       };
+                       let last_fee = Readable::read(reader)?;
+                       our_claim_txn_waiting_first_conf.insert(outpoint, (height_target, tx_material, last_fee));
+               }
+
                let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
                let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
                for _ in 0..waiting_threshold_conf_len {
@@ -2507,6 +2714,8 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
 
                        destination_script,
 
+                       our_claim_txn_waiting_first_conf,
+
                        onchain_events_waiting_threshold_conf,
 
                        last_block_hash,