Avoid claiming remote received HTLCs with preimage
[rust-lightning] / src / ln / channelmonitor.rs
index 2ddb2690ad8ed00de00090c7d3449b9397cba8f9..9deb11073ffc31273d233277070f528c4eca478f 100644 (file)
@@ -303,12 +303,24 @@ const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
-/// copies of ChannelMonitors, including watchtowers).
-pub(crate) const HTLC_FAIL_TIMEOUT_BLOCKS: u32 = 3;
-/// Number of blocks we wait on seeing a confirmed HTLC-Timeout or previous revoked commitment
-/// transaction before we fail corresponding inbound HTLCs. This prevents us from failing backwards
-/// and then getting a reorg resulting in us losing money.
-pub(crate) const HTLC_FAIL_ANTI_REORG_DELAY: u32 = 6;
+/// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
+/// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
+/// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
+/// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
+/// due to expiration but increase the cost of funds being locked longuer in case of failure.
+/// This delay also cover a low-power peer being slow to process blocks and so being behind us on
+/// accurate block height.
+/// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
+/// with at worst this delay, so we are not only using this value as a mercy for them but also
+/// us as a safeguard to delay with enough time.
+pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
+/// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
+/// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
+/// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
+/// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
+/// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
+/// keeping bumping another claim tx to solve the outpoint.
+pub(crate) const ANTI_REORG_DELAY: u32 = 6;
 
 #[derive(Clone, PartialEq)]
 enum Storage {
@@ -352,8 +364,34 @@ 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 (HTLC_FAIL_ANTI_REORG_DELAY)
+/// once they mature to enough confirmations (ANTI_REORG_DELAY)
 #[derive(Clone, PartialEq)]
 enum OnchainEvent {
        /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
@@ -418,6 +456,18 @@ pub struct ChannelMonitor {
        payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
 
        destination_script: Script,
+       // Thanks to data loss protection, we may be able to claim our non-htlc funds
+       // back, this is the script we have to spend from but we need to
+       // scan every commitment transaction for that
+       to_remote_rescue: Option<(Script, SecretKey)>,
+
+       // 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), if timelock expiration (u32) is near, decrease height timer, the in-between bumps delay.
+       // Last field cached (u32) is height of outpoint confirmation, which is needed to flush this tracker
+       // in case of reorgs, given block timer are scaled on timer expiration we can't deduce from it original height.
+       our_claim_txn_waiting_first_conf: HashMap<BitcoinOutPoint, (u32, TxMaterial, u64, u32, u32)>,
 
        // 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
@@ -435,13 +485,16 @@ 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 as u64) / 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 as u64) / 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 as u64) / 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);
@@ -486,6 +539,8 @@ 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.to_remote_rescue != other.to_remote_rescue ||
+                       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
@@ -535,6 +590,9 @@ impl ChannelMonitor {
 
                        payment_preimages: HashMap::new(),
                        destination_script: destination_script,
+                       to_remote_rescue: None,
+
+                       our_claim_txn_waiting_first_conf: HashMap::new(),
 
                        onchain_events_waiting_threshold_conf: HashMap::new(),
 
@@ -544,7 +602,7 @@ impl ChannelMonitor {
                }
        }
 
-       fn get_witnesses_weight(inputs: &[InputDescriptors]) -> u64 {
+       fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
                let mut tx_weight = 2; // count segwit flags
                for inp in inputs {
                        // We use expected weight (and not actual) as signatures and time lock delays may vary
@@ -574,6 +632,15 @@ impl ChannelMonitor {
                tx_weight
        }
 
+       fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
+               if timelock_expiration <= current_height || timelock_expiration - current_height <= 3 {
+                       return current_height + 1
+               } else if timelock_expiration - current_height <= 15 {
+                       return current_height + 3
+               }
+               current_height + 15
+       }
+
        #[inline]
        fn place_secret(idx: u64) -> u8 {
                for i in 0..48 {
@@ -702,6 +769,22 @@ impl ChannelMonitor {
                }
        }
 
+       pub(super) fn provide_rescue_remote_commitment_tx_info(&mut self, their_revocation_point: PublicKey) {
+               match self.key_storage {
+                       Storage::Local { ref payment_base_key, .. } => {
+                               if let Ok(payment_key) = chan_utils::derive_public_key(&self.secp_ctx, &their_revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &payment_base_key)) {
+                                       let to_remote_script =  Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
+                                               .push_slice(&Hash160::hash(&payment_key.serialize())[..])
+                                               .into_script();
+                                       if let Ok(to_remote_key) = chan_utils::derive_private_key(&self.secp_ctx, &their_revocation_point, &payment_base_key) {
+                                               self.to_remote_rescue = Some((to_remote_script, to_remote_key));
+                                       }
+                               }
+                       },
+                       Storage::Watchtower { .. } => {}
+               }
+       }
+
        /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
        /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
        /// is important that any clones of this channel monitor (including remote clones) by kept
@@ -791,6 +874,7 @@ impl ChannelMonitor {
                                self.current_local_signed_commitment_tx = Some(local_tx);
                        }
                        self.payment_preimages = other.payment_preimages;
+                       self.to_remote_rescue = other.to_remote_rescue;
                }
 
                self.current_remote_commitment_number = cmp::min(self.current_remote_commitment_number, other.current_remote_commitment_number);
@@ -1044,6 +1128,51 @@ impl ChannelMonitor {
 
                self.last_block_hash.write(writer)?;
                self.destination_script.write(writer)?;
+               if let Some((ref to_remote_script, ref local_key)) = self.to_remote_rescue {
+                       writer.write_all(&[1; 1])?;
+                       to_remote_script.write(writer)?;
+                       local_key.write(writer)?;
+               } else {
+                       writer.write_all(&[0; 1])?;
+               }
+
+               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::be32_to_array(claim_tx_data.3))?;
+                       writer.write_all(&byte_utils::be32_to_array(claim_tx_data.4))?;
+               }
 
                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() {
@@ -1181,10 +1310,9 @@ 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 {
@@ -1197,10 +1325,9 @@ 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, self.our_to_self_delay as u32));
                                        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 },
@@ -1213,7 +1340,7 @@ 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;
@@ -1221,7 +1348,7 @@ 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!();
@@ -1234,7 +1361,8 @@ 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)
                                        }
                                }
                        }
@@ -1261,10 +1389,9 @@ 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, htlc.cltv_expiry));
+                                                       total_value += tx.output[transaction_output_index as usize].value;
                                                } else {
                                                        let mut single_htlc_tx = Transaction {
                                                                version: 2,
@@ -1276,10 +1403,16 @@ 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 height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                                       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_timer, TxMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
+                                                               }
                                                                txn_to_broadcast.push(single_htlc_tx);
                                                        }
                                                }
@@ -1298,8 +1431,8 @@ impl ChannelMonitor {
                                                if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
                                                        for &(ref htlc, ref source_option) in outpoints.iter() {
                                                                if let &Some(ref source) = source_option {
-                                                                       log_info!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + HTLC_FAIL_ANTI_REORG_DELAY - 1);
-                                                                       match self.onchain_events_waiting_threshold_conf.entry(height + HTLC_FAIL_ANTI_REORG_DELAY - 1) {
+                                                                       log_info!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
+                                                                       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| {
@@ -1343,18 +1476,23 @@ 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 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);
+                               let height_timer = Self::get_height_timer(height, info.2);
+                               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_timer, 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, if !info.0.is_some() { height + info.2 } else { info.2 }, height)); }
+                               }
                        }
                        assert!(predicted_weight >= spend_tx.get_weight());
 
@@ -1396,7 +1534,7 @@ impl ChannelMonitor {
                                                                        }
                                                                }
                                                                log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
-                                                               match self.onchain_events_waiting_threshold_conf.entry(height + HTLC_FAIL_ANTI_REORG_DELAY - 1) {
+                                                               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| {
@@ -1468,20 +1606,20 @@ 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!();
@@ -1490,7 +1628,8 @@ 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)
                                                        }
                                                }
                                        }
@@ -1504,40 +1643,48 @@ impl ChannelMonitor {
                                                                return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user
                                                        }
                                                        if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
-                                                               let input = TxIn {
-                                                                       previous_output: BitcoinOutPoint {
-                                                                               txid: commitment_txid,
-                                                                               vout: transaction_output_index,
-                                                                       },
-                                                                       script_sig: Script::new(),
-                                                                       sequence: idx as u32, // reset to 0xfffffffd in sign_input
-                                                                       witness: Vec::new(),
-                                                               };
-                                                               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 });
-                                                               } else {
-                                                                       let mut single_htlc_tx = Transaction {
-                                                                               version: 2,
-                                                                               lock_time: 0,
-                                                                               input: vec![input],
-                                                                               output: vec!(TxOut {
-                                                                                       script_pubkey: self.destination_script.clone(),
-                                                                                       value: htlc.amount_msat / 1000,
-                                                                               }),
+                                                               if htlc.offered {
+                                                                       let input = TxIn {
+                                                                               previous_output: BitcoinOutPoint {
+                                                                                       txid: commitment_txid,
+                                                                                       vout: transaction_output_index,
+                                                                               },
+                                                                               script_sig: Script::new(),
+                                                                               sequence: idx as u32, // reset to 0xfffffffd in sign_input
+                                                                               witness: Vec::new(),
                                                                        };
-                                                                       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 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());
-                                                                               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(),
-                                                                               });
-                                                                               txn_to_broadcast.push(single_htlc_tx);
+                                                                       if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
+                                                                               inputs.push(input);
+                                                                               inputs_desc.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
+                                                                               inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value, htlc.cltv_expiry));
+                                                                               total_value += tx.output[transaction_output_index as usize].value;
+                                                                       } else {
+                                                                               let mut single_htlc_tx = Transaction {
+                                                                                       version: 2,
+                                                                                       lock_time: 0,
+                                                                                       input: vec![input],
+                                                                                       output: vec!(TxOut {
+                                                                                               script_pubkey: self.destination_script.clone(),
+                                                                                               value: htlc.amount_msat / 1000,
+                                                                                       }),
+                                                                               };
+                                                                               let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }]);
+                                                                               let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                                                               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);
+                                                                                       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_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
+                                                                                       }
+                                                                                       txn_to_broadcast.push(single_htlc_tx);
+                                                                               }
                                                                        }
                                                                }
                                                        }
@@ -1562,8 +1709,19 @@ 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 height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                                               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_timer, TxMaterial::RemoteHTLC { script : redeemscript, key: htlc_key, preimage: None, amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
+                                                                       }
+                                                               }
                                                                txn_to_broadcast.push(timeout_tx);
                                                        }
                                                }
@@ -1581,19 +1739,24 @@ 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());
+                                               let height_timer = Self::get_height_timer(height, info.2);
+                                               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_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1}, used_feerate, info.2, height)); }
+                                               }
                                        }
-
                                        assert!(predicted_weight >= spend_tx.get_weight());
                                        spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
                                                outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
@@ -1602,13 +1765,23 @@ impl ChannelMonitor {
                                        txn_to_broadcast.push(spend_tx);
                                }
                        }
+               } else if let Some((ref to_remote_rescue, ref local_key)) = self.to_remote_rescue {
+                       for (idx, outp) in tx.output.iter().enumerate() {
+                               if to_remote_rescue == &outp.script_pubkey {
+                                       spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
+                                               outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
+                                               key: local_key.clone(),
+                                               output: outp.clone(),
+                                       });
+                               }
+                       }
                }
 
                (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs)
        }
 
        /// 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)
                }
@@ -1637,7 +1810,7 @@ impl ChannelMonitor {
                        None => return (None, None),
                        Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
                };
-               let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
+               let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
                let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
                let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 
@@ -1670,17 +1843,18 @@ 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!();
@@ -1689,19 +1863,25 @@ 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();
+                       let height_timer = Self::get_height_timer(height, self.their_to_self_delay.unwrap() as u32); // We can safely unwrap given we are past channel opening
+                       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_timer, TxMaterial::Revoked { script: redeemscript, pubkey: None, key: revocation_key, is_htlc: false, amount: tx.output[0].value }, used_feerate, height + self.our_to_self_delay as u32, height)); }
+                       }
                        (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, u32, u32))>) {
                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) => {
@@ -1746,9 +1926,12 @@ 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);
+                                               let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                               pending_claims.push((htlc_timeout_tx.input[0].previous_output.clone(), (height_timer, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: None, amount: htlc.amount_msat / 1000}, 0, htlc.cltv_expiry, height)));
                                                res.push(htlc_timeout_tx);
                                        } else {
                                                if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1763,9 +1946,12 @@ 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);
+                                                       let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                                       pending_claims.push((htlc_success_tx.input[0].previous_output.clone(), (height_timer, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000}, 0, htlc.cltv_expiry, height)));
                                                        res.push(htlc_success_tx);
                                                }
                                        }
@@ -1774,7 +1960,7 @@ 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)
@@ -1788,8 +1974,8 @@ impl ChannelMonitor {
 
                macro_rules! wait_threshold_conf {
                        ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
-                               log_trace!(self, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + HTLC_FAIL_ANTI_REORG_DELAY - 1);
-                               match self.onchain_events_waiting_threshold_conf.entry($height + HTLC_FAIL_ANTI_REORG_DELAY - 1) {
+                               log_trace!(self, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
+                               match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
                                        hash_map::Entry::Occupied(mut entry) => {
                                                let e = entry.get_mut();
                                                e.retain(|ref event| {
@@ -1814,6 +2000,12 @@ 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); }
+                                       }
+                               }
                        }
                }
 
@@ -1826,10 +2018,10 @@ 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));
                                        }
                                }
                        }
@@ -1840,10 +2032,10 @@ 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));
                                        }
                                }
                        }
@@ -1898,14 +2090,23 @@ impl ChannelMonitor {
                None
        }
 
-       /// Used by ChannelManager deserialization to broadcast the latest local state if it's copy of
-       /// the Channel was out-of-date.
-       pub(super) fn get_latest_local_commitment_txn(&self) -> Vec<Transaction> {
+       /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
+       /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
+       /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
+       /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
+       /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
+       /// broadcast them if remote don't close channel with his higher commitment transaction after a
+       /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
+       /// out-of-band the other node operator to coordinate with him if option is available to you.
+       /// In any-case, choice is up to the user.
+       pub fn get_latest_local_commitment_txn(&self) -> Vec<Transaction> {
                if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
                        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"),
                        };
@@ -1936,19 +2137,21 @@ impl ChannelMonitor {
                                        }
                                };
                                if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) {
-                                       let (remote_txn, new_outputs, mut spendable_output) = self.check_spend_remote_transaction(tx, height, fee_estimator);
-                                       txn = remote_txn;
-                                       spendable_outputs.append(&mut spendable_output);
-                                       if !new_outputs.1.is_empty() {
-                                               watch_outputs.push(new_outputs);
-                                       }
-                                       if txn.is_empty() {
-                                               let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height);
+                                       if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
+                                               let (remote_txn, new_outputs, mut spendable_output) = self.check_spend_remote_transaction(tx, height, fee_estimator);
+                                               txn = remote_txn;
                                                spendable_outputs.append(&mut spendable_output);
-                                               txn = local_txn;
                                                if !new_outputs.1.is_empty() {
                                                        watch_outputs.push(new_outputs);
                                                }
+                                               if txn.is_empty() {
+                                                       let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height);
+                                                       spendable_outputs.append(&mut spendable_output);
+                                                       txn = local_txn;
+                                                       if !new_outputs.1.is_empty() {
+                                                               watch_outputs.push(new_outputs);
+                                                       }
+                                               }
                                        }
                                        if !funding_txo.is_none() && txn.is_empty() {
                                                if let Some(spendable_output) = self.check_spend_closing_transaction(tx) {
@@ -1957,7 +2160,7 @@ 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);
                                                }
@@ -1977,14 +2180,37 @@ 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));
                                                }
@@ -1993,8 +2219,9 @@ 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));
                                                }
@@ -2005,10 +2232,17 @@ 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));
@@ -2017,16 +2251,18 @@ 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)
        }
 
        fn block_disconnected(&mut self, height: u32, block_hash: &Sha256dHash) {
-               if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + HTLC_FAIL_ANTI_REORG_DELAY - 1)) {
+               if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
                        //We may discard:
                        //- 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.3 == height { false } else { true });
                self.last_block_hash = block_hash.clone();
        }
 
@@ -2059,16 +2295,16 @@ impl ChannelMonitor {
                                        // from us until we've reached the point where we go on-chain with the
                                        // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
                                        // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
-                                       //  aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
+                                       //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
                                        //      inbound_cltv == height + CLTV_CLAIM_BUFFER
-                                       //      outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
-                                       //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
+                                       //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
+                                       //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
                                        //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
-                                       //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
+                                       //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
                                        //  The final, above, condition is checked for statically in channelmanager
                                        //  with CHECK_CLTV_EXPIRY_SANITY_2.
                                        let htlc_outbound = $local_tx == htlc.offered;
-                                       if ( htlc_outbound && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
+                                       if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
                                           (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
                                                log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
                                                return true;
@@ -2206,8 +2442,8 @@ impl ChannelMonitor {
                                        payment_preimage.0.copy_from_slice(&input.witness[1]);
                                        htlc_updated.push((source, Some(payment_preimage), payment_hash));
                                } else {
-                                       log_info!(self, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), height + HTLC_FAIL_ANTI_REORG_DELAY - 1);
-                                       match self.onchain_events_waiting_threshold_conf.entry(height + HTLC_FAIL_ANTI_REORG_DELAY - 1) {
+                                       log_info!(self, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), height + ANTI_REORG_DELAY - 1);
+                                       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| {
@@ -2442,6 +2678,72 @@ 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 to_remote_rescue = match <u8 as Readable<R>>::read(reader)? {
+                       0 => None,
+                       1 => {
+                               let to_remote_script = Readable::read(reader)?;
+                               let local_key = Readable::read(reader)?;
+                               Some((to_remote_script, local_key))
+                       }
+                       _ => return Err(DecodeError::InvalidValue),
+               };
+
+               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)?;
+                       let timelock_expiration = Readable::read(reader)?;
+                       let height = Readable::read(reader)?;
+                       our_claim_txn_waiting_first_conf.insert(outpoint, (height_target, tx_material, last_fee, timelock_expiration, height));
+               }
 
                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));
@@ -2494,6 +2796,9 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        payment_preimages,
 
                        destination_script,
+                       to_remote_rescue,
+
+                       our_claim_txn_waiting_first_conf,
 
                        onchain_events_waiting_threshold_conf,
 
@@ -3004,7 +3309,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
                let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
-               let mut sum_actual_sigs: u64 = 0;
+               let mut sum_actual_sigs = 0;
 
                macro_rules! sign_input {
                        ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
@@ -3020,7 +3325,7 @@ mod tests {
                                let sig = secp_ctx.sign(&sighash, &privkey);
                                $input.witness.push(sig.serialize_der().to_vec());
                                $input.witness[0].push(SigHashType::All as u8);
-                               sum_actual_sigs += $input.witness[0].len() as u64;
+                               sum_actual_sigs += $input.witness[0].len();
                                if *$input_type == InputDescriptors::RevokedOutput {
                                        $input.witness.push(vec!(1));
                                } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
@@ -3063,7 +3368,7 @@ mod tests {
                for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
                        sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
                }
-               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
+               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
 
                // Claim tx with 1 offered HTLCs, 3 received HTLCs
                claim_tx.input.clear();
@@ -3085,7 +3390,7 @@ mod tests {
                for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
                        sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
                }
-               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
+               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
 
                // Justice tx with 1 revoked HTLC-Success tx output
                claim_tx.input.clear();
@@ -3105,7 +3410,7 @@ mod tests {
                for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
                        sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
                }
-               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
+               assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
        }
 
        // Further testing is done in the ChannelManager integration tests.