Relicense as dual Apache-2.0 + MIT
[rust-lightning] / lightning / src / ln / channelmonitor.rs
index c59ed9fc6ad74d2e76054ebedb5df02ed00ebf19..28ca19fe0817617d06a5f457c8315de071e85bc7 100644 (file)
@@ -1,3 +1,12 @@
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
 //! here.
 //!
@@ -149,66 +158,6 @@ pub struct HTLCUpdate {
 }
 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
 
-/// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
-/// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
-/// events to it, while also taking any add/update_monitor events and passing them to some remote
-/// server(s).
-///
-/// In general, you must always have at least one local copy in memory, which must never fail to
-/// update (as it is responsible for broadcasting the latest state in case the channel is closed),
-/// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
-/// to update (eg out-of-memory or some other condition), you must immediately shut down without
-/// taking any further action such as writing the current state to disk. This should likely be
-/// accomplished via panic!() or abort().
-///
-/// Note that any updates to a channel's monitor *must* be applied to each instance of the
-/// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
-/// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
-/// which we have revoked, allowing our counterparty to claim all funds in the channel!
-///
-/// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
-/// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
-/// than calling these methods directly, the user should register implementors as listeners to the
-/// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
-/// all registered listeners in one go.
-pub trait ManyChannelMonitor<ChanSigner: ChannelKeys>: Send + Sync {
-       /// Adds a monitor for the given `funding_txo`.
-       ///
-       /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
-       /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
-       /// callbacks with the funding transaction, or any spends of it.
-       ///
-       /// Further, the implementer must also ensure that each output returned in
-       /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
-       /// any spends of any of the outputs.
-       ///
-       /// Any spends of outputs which should have been registered which aren't passed to
-       /// ChannelMonitors via block_connected may result in FUNDS LOSS.
-       fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr>;
-
-       /// Updates a monitor for the given `funding_txo`.
-       ///
-       /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
-       /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
-       /// callbacks with the funding transaction, or any spends of it.
-       ///
-       /// Further, the implementer must also ensure that each output returned in
-       /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
-       /// any spends of any of the outputs.
-       ///
-       /// Any spends of outputs which should have been registered which aren't passed to
-       /// ChannelMonitors via block_connected may result in FUNDS LOSS.
-       fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
-
-       /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
-       /// with success or failure.
-       ///
-       /// You should probably just call through to
-       /// ChannelMonitor::get_and_clear_pending_htlcs_updated() for each ChannelMonitor and return
-       /// the full list.
-       fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate>;
-}
-
 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
 /// watchtower or watch our own channels.
 ///
@@ -243,7 +192,7 @@ impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync
              L::Target: Logger,
         C::Target: ChainWatchInterface,
 {
-       fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
+       fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[usize]) {
                let block_hash = header.bitcoin_hash();
                {
                        let mut monitors = self.monitors.lock().unwrap();
@@ -295,12 +244,15 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
                        hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
                        hash_map::Entry::Vacant(e) => e,
                };
-               log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(monitor.funding_info.0.to_channel_id()[..]));
-               self.chain_monitor.install_watch_tx(&monitor.funding_info.0.txid, &monitor.funding_info.1);
-               self.chain_monitor.install_watch_outpoint((monitor.funding_info.0.txid, monitor.funding_info.0.index as u32), &monitor.funding_info.1);
-               for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
-                       for (idx, script) in outputs.iter().enumerate() {
-                               self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
+               {
+                       let funding_txo = monitor.get_funding_txo();
+                       log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
+                       self.chain_monitor.install_watch_tx(&funding_txo.0.txid, &funding_txo.1);
+                       self.chain_monitor.install_watch_outpoint((funding_txo.0.txid, funding_txo.0.index as u32), &funding_txo.1);
+                       for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
+                               for (idx, script) in outputs.iter().enumerate() {
+                                       self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
+                               }
                        }
                }
                entry.insert(monitor);
@@ -320,12 +272,14 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
        }
 }
 
-impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F, L, C>
+impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send> ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F, L, C>
        where T::Target: BroadcasterInterface,
              F::Target: FeeEstimator,
              L::Target: Logger,
         C::Target: ChainWatchInterface,
 {
+       type Keys = ChanSigner;
+
        fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
                match self.add_monitor_by_key(funding_txo, monitor) {
                        Ok(_) => Ok(()),
@@ -424,28 +378,88 @@ struct LocalSignedTx {
        b_htlc_key: PublicKey,
        delayed_payment_key: PublicKey,
        per_commitment_point: PublicKey,
-       feerate_per_kw: u64,
+       feerate_per_kw: u32,
        htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
 }
 
+/// We use this to track remote commitment transactions and htlcs outputs and
+/// use it to generate any justice or 2nd-stage preimage/timeout transactions.
+#[derive(PartialEq)]
+struct RemoteCommitmentTransaction {
+       remote_delayed_payment_base_key: PublicKey,
+       remote_htlc_base_key: PublicKey,
+       on_remote_tx_csv: u16,
+       per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
+}
+
+impl Writeable for RemoteCommitmentTransaction {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+               self.remote_delayed_payment_base_key.write(w)?;
+               self.remote_htlc_base_key.write(w)?;
+               w.write_all(&byte_utils::be16_to_array(self.on_remote_tx_csv))?;
+               w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
+               for (ref txid, ref htlcs) in self.per_htlc.iter() {
+                       w.write_all(&txid[..])?;
+                       w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
+                       for &ref htlc in htlcs.iter() {
+                               htlc.write(w)?;
+                       }
+               }
+               Ok(())
+       }
+}
+impl Readable for RemoteCommitmentTransaction {
+       fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+               let remote_commitment_transaction = {
+                       let remote_delayed_payment_base_key = Readable::read(r)?;
+                       let remote_htlc_base_key = Readable::read(r)?;
+                       let on_remote_tx_csv: u16 = Readable::read(r)?;
+                       let per_htlc_len: u64 = Readable::read(r)?;
+                       let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
+                       for _  in 0..per_htlc_len {
+                               let txid: Txid = Readable::read(r)?;
+                               let htlcs_count: u64 = Readable::read(r)?;
+                               let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
+                               for _ in 0..htlcs_count {
+                                       let htlc = Readable::read(r)?;
+                                       htlcs.push(htlc);
+                               }
+                               if let Some(_) = per_htlc.insert(txid, htlcs) {
+                                       return Err(DecodeError::InvalidValue);
+                               }
+                       }
+                       RemoteCommitmentTransaction {
+                               remote_delayed_payment_base_key,
+                               remote_htlc_base_key,
+                               on_remote_tx_csv,
+                               per_htlc,
+                       }
+               };
+               Ok(remote_commitment_transaction)
+       }
+}
+
 /// 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)]
 pub(crate) enum InputMaterial {
        Revoked {
-               witness_script: Script,
-               pubkey: Option<PublicKey>,
-               key: SecretKey,
+               per_commitment_point: PublicKey,
+               remote_delayed_payment_base_key: PublicKey,
+               remote_htlc_base_key: PublicKey,
+               per_commitment_key: SecretKey,
                input_descriptor: InputDescriptors,
                amount: u64,
+               htlc: Option<HTLCOutputInCommitment>,
+               on_remote_tx_csv: u16,
        },
        RemoteHTLC {
-               witness_script: Script,
-               key: SecretKey,
+               per_commitment_point: PublicKey,
+               remote_delayed_payment_base_key: PublicKey,
+               remote_htlc_base_key: PublicKey,
                preimage: Option<PaymentPreimage>,
-               amount: u64,
-               locktime: u32,
+               htlc: HTLCOutputInCommitment
        },
        LocalHTLC {
                preimage: Option<PaymentPreimage>,
@@ -459,21 +473,24 @@ pub(crate) enum InputMaterial {
 impl Writeable for InputMaterial  {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
                match self {
-                       &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref input_descriptor, ref amount} => {
+                       &InputMaterial::Revoked { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_remote_tx_csv} => {
                                writer.write_all(&[0; 1])?;
-                               witness_script.write(writer)?;
-                               pubkey.write(writer)?;
-                               writer.write_all(&key[..])?;
+                               per_commitment_point.write(writer)?;
+                               remote_delayed_payment_base_key.write(writer)?;
+                               remote_htlc_base_key.write(writer)?;
+                               writer.write_all(&per_commitment_key[..])?;
                                input_descriptor.write(writer)?;
                                writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                               htlc.write(writer)?;
+                               on_remote_tx_csv.write(writer)?;
                        },
-                       &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
+                       &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc} => {
                                writer.write_all(&[1; 1])?;
-                               witness_script.write(writer)?;
-                               key.write(writer)?;
+                               per_commitment_point.write(writer)?;
+                               remote_delayed_payment_base_key.write(writer)?;
+                               remote_htlc_base_key.write(writer)?;
                                preimage.write(writer)?;
-                               writer.write_all(&byte_utils::be64_to_array(*amount))?;
-                               writer.write_all(&byte_utils::be32_to_array(*locktime))?;
+                               htlc.write(writer)?;
                        },
                        &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
                                writer.write_all(&[2; 1])?;
@@ -493,31 +510,37 @@ impl Readable for InputMaterial {
        fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                let input_material = match <u8 as Readable>::read(reader)? {
                        0 => {
-                               let witness_script = Readable::read(reader)?;
-                               let pubkey = Readable::read(reader)?;
-                               let key = Readable::read(reader)?;
+                               let per_commitment_point = Readable::read(reader)?;
+                               let remote_delayed_payment_base_key = Readable::read(reader)?;
+                               let remote_htlc_base_key = Readable::read(reader)?;
+                               let per_commitment_key = Readable::read(reader)?;
                                let input_descriptor = Readable::read(reader)?;
                                let amount = Readable::read(reader)?;
+                               let htlc = Readable::read(reader)?;
+                               let on_remote_tx_csv = Readable::read(reader)?;
                                InputMaterial::Revoked {
-                                       witness_script,
-                                       pubkey,
-                                       key,
+                                       per_commitment_point,
+                                       remote_delayed_payment_base_key,
+                                       remote_htlc_base_key,
+                                       per_commitment_key,
                                        input_descriptor,
-                                       amount
+                                       amount,
+                                       htlc,
+                                       on_remote_tx_csv
                                }
                        },
                        1 => {
-                               let witness_script = Readable::read(reader)?;
-                               let key = Readable::read(reader)?;
+                               let per_commitment_point = Readable::read(reader)?;
+                               let remote_delayed_payment_base_key = Readable::read(reader)?;
+                               let remote_htlc_base_key = Readable::read(reader)?;
                                let preimage = Readable::read(reader)?;
-                               let amount = Readable::read(reader)?;
-                               let locktime = Readable::read(reader)?;
+                               let htlc = Readable::read(reader)?;
                                InputMaterial::RemoteHTLC {
-                                       witness_script,
-                                       key,
+                                       per_commitment_point,
+                                       remote_delayed_payment_base_key,
+                                       remote_htlc_base_key,
                                        preimage,
-                                       amount,
-                                       locktime
+                                       htlc
                                }
                        },
                        2 => {
@@ -716,7 +739,7 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        commitment_transaction_number_obscure_factor: u64,
 
        destination_script: Script,
-       broadcasted_local_revokable_script: Option<(Script, SecretKey, Script)>,
+       broadcasted_local_revokable_script: Option<(Script, PublicKey, PublicKey)>,
        remote_payment_script: Script,
        shutdown_script: Script,
 
@@ -725,15 +748,13 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        current_remote_commitment_txid: Option<Txid>,
        prev_remote_commitment_txid: Option<Txid>,
 
-       their_htlc_base_key: PublicKey,
-       their_delayed_payment_base_key: PublicKey,
+       remote_tx_cache: RemoteCommitmentTransaction,
        funding_redeemscript: Script,
        channel_value_satoshis: u64,
        // first is the idx of the first of the two revocation points
        their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 
-       our_to_self_delay: u16,
-       their_to_self_delay: u16,
+       on_local_tx_csv: u16,
 
        commitment_secrets: CounterpartyCommitmentSecrets,
        remote_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
@@ -803,6 +824,70 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 }
 
+/// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
+/// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
+/// events to it, while also taking any add/update_monitor events and passing them to some remote
+/// server(s).
+///
+/// In general, you must always have at least one local copy in memory, which must never fail to
+/// update (as it is responsible for broadcasting the latest state in case the channel is closed),
+/// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
+/// to update (eg out-of-memory or some other condition), you must immediately shut down without
+/// taking any further action such as writing the current state to disk. This should likely be
+/// accomplished via panic!() or abort().
+///
+/// Note that any updates to a channel's monitor *must* be applied to each instance of the
+/// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
+/// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
+/// which we have revoked, allowing our counterparty to claim all funds in the channel!
+///
+/// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
+/// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
+/// than calling these methods directly, the user should register implementors as listeners to the
+/// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
+/// all registered listeners in one go.
+pub trait ManyChannelMonitor: Send + Sync {
+       /// The concrete type which signs for transactions and provides access to our channel public
+       /// keys.
+       type Keys: ChannelKeys;
+
+       /// Adds a monitor for the given `funding_txo`.
+       ///
+       /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
+       /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
+       /// callbacks with the funding transaction, or any spends of it.
+       ///
+       /// Further, the implementer must also ensure that each output returned in
+       /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
+       /// any spends of any of the outputs.
+       ///
+       /// Any spends of outputs which should have been registered which aren't passed to
+       /// ChannelMonitors via block_connected may result in FUNDS LOSS.
+       fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
+
+       /// Updates a monitor for the given `funding_txo`.
+       ///
+       /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
+       /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
+       /// callbacks with the funding transaction, or any spends of it.
+       ///
+       /// Further, the implementer must also ensure that each output returned in
+       /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
+       /// any spends of any of the outputs.
+       ///
+       /// Any spends of outputs which should have been registered which aren't passed to
+       /// ChannelMonitors via block_connected may result in FUNDS LOSS.
+       fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
+
+       /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
+       /// with success or failure.
+       ///
+       /// You should probably just call through to
+       /// ChannelMonitor::get_and_clear_pending_htlcs_updated() for each ChannelMonitor and return
+       /// the full list.
+       fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate>;
+}
+
 #[cfg(any(test, feature = "fuzztarget"))]
 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 /// underlying object
@@ -817,13 +902,11 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                        self.funding_info != other.funding_info ||
                        self.current_remote_commitment_txid != other.current_remote_commitment_txid ||
                        self.prev_remote_commitment_txid != other.prev_remote_commitment_txid ||
-                       self.their_htlc_base_key != other.their_htlc_base_key ||
-                       self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
+                       self.remote_tx_cache != other.remote_tx_cache ||
                        self.funding_redeemscript != other.funding_redeemscript ||
                        self.channel_value_satoshis != other.channel_value_satoshis ||
                        self.their_cur_revocation_points != other.their_cur_revocation_points ||
-                       self.our_to_self_delay != other.our_to_self_delay ||
-                       self.their_to_self_delay != other.their_to_self_delay ||
+                       self.on_local_tx_csv != other.on_local_tx_csv ||
                        self.commitment_secrets != other.commitment_secrets ||
                        self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
                        self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
@@ -886,8 +969,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                self.current_remote_commitment_txid.write(writer)?;
                self.prev_remote_commitment_txid.write(writer)?;
 
-               writer.write_all(&self.their_htlc_base_key.serialize())?;
-               writer.write_all(&self.their_delayed_payment_base_key.serialize())?;
+               self.remote_tx_cache.write(writer)?;
                self.funding_redeemscript.write(writer)?;
                self.channel_value_satoshis.write(writer)?;
 
@@ -909,8 +991,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                        },
                }
 
-               writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
-               writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay))?;
+               writer.write_all(&byte_utils::be16_to_array(self.on_local_tx_csv))?;
 
                self.commitment_secrets.write(writer)?;
 
@@ -959,7 +1040,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                                writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
                                writer.write_all(&$local_tx.per_commitment_point.serialize())?;
 
-                               writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
+                               writer.write_all(&byte_utils::be32_to_array($local_tx.feerate_per_kw))?;
                                writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
                                for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
                                        serialize_htlc_in_commitment!(htlc_output);
@@ -1041,9 +1122,9 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
 
 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
-                       our_to_self_delay: u16, destination_script: &Script, funding_info: (OutPoint, Script),
-                       their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey,
-                       their_to_self_delay: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
+                       on_remote_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
+                       remote_htlc_base_key: &PublicKey, remote_delayed_payment_base_key: &PublicKey,
+                       on_local_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
                        commitment_transaction_number_obscure_factor: u64,
                        initial_local_commitment_tx: LocalCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
 
@@ -1053,7 +1134,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
                let remote_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
 
-               let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), their_to_self_delay, their_delayed_payment_base_key.clone(), their_htlc_base_key.clone(), our_to_self_delay);
+               let remote_tx_cache = RemoteCommitmentTransaction { remote_delayed_payment_base_key: *remote_delayed_payment_base_key, remote_htlc_base_key: *remote_htlc_base_key, on_remote_tx_csv, per_htlc: HashMap::new() };
+
+               let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_local_tx_csv);
 
                let local_tx_sequence = initial_local_commitment_tx.unsigned_tx.input[0].sequence as u64;
                let local_tx_locktime = initial_local_commitment_tx.unsigned_tx.lock_time as u64;
@@ -1088,14 +1171,12 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        current_remote_commitment_txid: None,
                        prev_remote_commitment_txid: None,
 
-                       their_htlc_base_key: *their_htlc_base_key,
-                       their_delayed_payment_base_key: *their_delayed_payment_base_key,
+                       remote_tx_cache,
                        funding_redeemscript,
                        channel_value_satoshis: channel_value_satoshis,
                        their_cur_revocation_points: None,
 
-                       our_to_self_delay,
-                       their_to_self_delay,
+                       on_local_tx_csv,
 
                        commitment_secrets: CounterpartyCommitmentSecrets::new(),
                        remote_claimable_outpoints: HashMap::new(),
@@ -1220,14 +1301,14 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                htlcs.push(htlc.0);
                        }
                }
-               self.onchain_tx_handler.provide_latest_remote_tx(new_txid, htlcs);
+               self.remote_tx_cache.per_htlc.insert(new_txid, htlcs);
        }
 
        /// 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
        /// up-to-date as our local commitment transaction is updated.
-       /// Panics if set_their_to_self_delay has never been called.
+       /// Panics if set_on_local_tx_csv has never been called.
        pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
                if self.local_tx_signed {
                        return Err(MonitorUpdateError("A local commitment tx has already been signed, no new local commitment txn can be sent to our counterparty"));
@@ -1339,8 +1420,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        }
 
        /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
-       pub fn get_funding_txo(&self) -> OutPoint {
-               self.funding_info.0
+       pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
+               &self.funding_info
        }
 
        /// Gets a list of txids, with their output scripts (in the order they appear in the
@@ -1430,19 +1511,16 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
                        let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
                        let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
-                       let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
-                       let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().htlc_basepoint));
-                       let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key));
-                       let a_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_htlc_base_key));
+                       let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.remote_tx_cache.remote_delayed_payment_base_key));
 
-                       let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
+                       let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.remote_tx_cache.on_remote_tx_csv, &delayed_key);
                        let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 
                        // First, process non-htlc outputs (to_local & to_remote)
                        for (idx, outp) in tx.output.iter().enumerate() {
                                if outp.script_pubkey == revokeable_p2wsh {
-                                       let witness_data = InputMaterial::Revoked { witness_script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value };
-                                       claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
+                                       let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv};
+                                       claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.remote_tx_cache.on_remote_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
                                }
                        }
 
@@ -1450,13 +1528,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        if let Some(ref per_commitment_data) = per_commitment_option {
                                for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
                                        if let Some(transaction_output_index) = htlc.transaction_output_index {
-                                               let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                                if transaction_output_index as usize >= tx.output.len() ||
-                                                               tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
-                                                               tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
+                                                               tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
                                                        return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
                                                }
-                                               let witness_data = InputMaterial::Revoked { witness_script: expected_script, pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value };
+                                               let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, per_commitment_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value, htlc: Some(htlc.clone()), on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv};
                                                claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
                                        }
                                }
@@ -1574,24 +1650,24 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                                if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
                                        } else { None };
                                if let Some(revocation_point) = revocation_point_option {
-                                       let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().revocation_basepoint));
-                                       let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().htlc_basepoint));
-                                       let htlc_privkey = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.keys.htlc_base_key()));
-                                       let a_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.their_htlc_base_key));
+                                       self.remote_payment_script = {
+                                               // Note that the Network here is ignored as we immediately drop the address for the
+                                               // script_pubkey version
+                                               let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
+                                               Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
+                                       };
 
                                        // Then, try to find htlc outputs
                                        for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
                                                if let Some(transaction_output_index) = htlc.transaction_output_index {
-                                                       let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                                        if transaction_output_index as usize >= tx.output.len() ||
-                                                                       tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
-                                                                       tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
+                                                                       tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
                                                                return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
                                                        }
                                                        let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
                                                        let aggregable = if !htlc.offered { false } else { true };
                                                        if preimage.is_some() || !htlc.offered {
-                                                               let witness_data = InputMaterial::RemoteHTLC { witness_script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry };
+                                                               let witness_data = InputMaterial::RemoteHTLC { per_commitment_point: *revocation_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, preimage, htlc: htlc.clone() };
                                                                claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
                                                        }
                                                }
@@ -1621,25 +1697,19 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
                let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
                let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
-               let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
-               let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
-               let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.their_delayed_payment_base_key));
-               let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 
                log_trace!(logger, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
-               let witness_data = InputMaterial::Revoked { witness_script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value };
-               let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
+               let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key,  per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv };
+               let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.remote_tx_cache.on_remote_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
                (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
        }
 
-       fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, SecretKey, Script)>) {
+       fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
                let mut claim_requests = Vec::with_capacity(local_tx.htlc_outputs.len());
                let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
 
-               let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay, &local_tx.delayed_payment_key);
-               let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, self.keys.delayed_payment_base_key()) {
-                       Some((redeemscript.to_v0_p2wsh(), local_delayedkey, redeemscript))
-               } else { None };
+               let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.on_local_tx_csv, &local_tx.delayed_payment_key);
+               let broadcasted_local_revokable_script = Some((redeemscript.to_v0_p2wsh(), local_tx.per_commitment_point.clone(), local_tx.revocation_key.clone()));
 
                for &(ref htlc, _, _) in local_tx.htlc_outputs.iter() {
                        if let Some(transaction_output_index) = htlc.transaction_output_index {
@@ -2138,18 +2208,19 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                if broadcasted_local_revokable_script.0 == outp.script_pubkey {
                                        spendable_output =  Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
                                                outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
-                                               key: broadcasted_local_revokable_script.1,
-                                               witness_script: broadcasted_local_revokable_script.2.clone(),
-                                               to_self_delay: self.their_to_self_delay,
+                                               per_commitment_point: broadcasted_local_revokable_script.1,
+                                               to_self_delay: self.on_local_tx_csv,
                                                output: outp.clone(),
+                                               key_derivation_params: self.keys.key_derivation_params(),
+                                               remote_revocation_pubkey: broadcasted_local_revokable_script.2.clone(),
                                        });
                                        break;
                                }
                        } else if self.remote_payment_script == outp.script_pubkey {
-                               spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WPKH {
+                               spendable_output = Some(SpendableOutputDescriptor::StaticOutputRemotePayment {
                                        outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
-                                       key: self.keys.payment_key().clone(),
                                        output: outp.clone(),
+                                       key_derivation_params: self.keys.key_derivation_params(),
                                });
                                break;
                        } else if outp.script_pubkey == self.shutdown_script {
@@ -2200,9 +2271,9 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
                        0 => {
                                let revokable_address = Readable::read(reader)?;
-                               let local_delayedkey = Readable::read(reader)?;
+                               let per_commitment_point = Readable::read(reader)?;
                                let revokable_script = Readable::read(reader)?;
-                               Some((revokable_address, local_delayedkey, revokable_script))
+                               Some((revokable_address, per_commitment_point, revokable_script))
                        },
                        1 => { None },
                        _ => return Err(DecodeError::InvalidValue),
@@ -2221,8 +2292,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                let current_remote_commitment_txid = Readable::read(reader)?;
                let prev_remote_commitment_txid = Readable::read(reader)?;
 
-               let their_htlc_base_key = Readable::read(reader)?;
-               let their_delayed_payment_base_key = Readable::read(reader)?;
+               let remote_tx_cache = Readable::read(reader)?;
                let funding_redeemscript = Readable::read(reader)?;
                let channel_value_satoshis = Readable::read(reader)?;
 
@@ -2241,8 +2311,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                        }
                };
 
-               let our_to_self_delay: u16 = Readable::read(reader)?;
-               let their_to_self_delay: u16 = Readable::read(reader)?;
+               let on_local_tx_csv: u16 = Readable::read(reader)?;
 
                let commitment_secrets = Readable::read(reader)?;
 
@@ -2310,7 +2379,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                                        let b_htlc_key = Readable::read(reader)?;
                                        let delayed_payment_key = Readable::read(reader)?;
                                        let per_commitment_point = Readable::read(reader)?;
-                                       let feerate_per_kw: u64 = Readable::read(reader)?;
+                                       let feerate_per_kw: u32 = Readable::read(reader)?;
 
                                        let htlcs_len: u64 = Readable::read(reader)?;
                                        let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
@@ -2431,14 +2500,12 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                        current_remote_commitment_txid,
                        prev_remote_commitment_txid,
 
-                       their_htlc_base_key,
-                       their_delayed_payment_base_key,
+                       remote_tx_cache,
                        funding_redeemscript,
                        channel_value_satoshis,
                        their_cur_revocation_points,
 
-                       our_to_self_delay,
-                       their_to_self_delay,
+                       on_local_tx_csv,
 
                        commitment_secrets,
                        remote_claimable_outpoints,
@@ -2489,7 +2556,6 @@ mod tests {
        use util::test_utils::TestLogger;
        use bitcoin::secp256k1::key::{SecretKey,PublicKey};
        use bitcoin::secp256k1::Secp256k1;
-       use rand::{thread_rng,Rng};
        use std::sync::Arc;
        use chain::keysinterface::InMemoryChannelKeys;
 
@@ -2503,10 +2569,8 @@ mod tests {
 
                let mut preimages = Vec::new();
                {
-                       let mut rng  = thread_rng();
-                       for _ in 0..20 {
-                               let mut preimage = PaymentPreimage([0; 32]);
-                               rng.fill_bytes(&mut preimage.0[..]);
+                       for i in 0..20 {
+                               let preimage = PaymentPreimage([i; 32]);
                                let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
                                preimages.push((preimage, hash));
                        }
@@ -2556,6 +2620,7 @@ mod tests {
                        SecretKey::from_slice(&[41; 32]).unwrap(),
                        [41; 32],
                        0,
+                       (0, 0)
                );
 
                // Prune with one old state and a local commitment tx holding a few overlaps with the