Rm ChannelMonitor merge capabilities in favor of explicit add/update
[rust-lightning] / lightning / src / ln / channelmonitor.rs
index 68674ac3ae098c3db7d70a173755e44232c77c44..113e007abead2b6c647cab3db68ffe7363cf0217 100644 (file)
@@ -31,7 +31,7 @@ use secp256k1;
 
 use ln::msgs::DecodeError;
 use ln::chan_utils;
-use ln::chan_utils::{HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
+use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
 use chain::transaction::OutPoint;
@@ -43,6 +43,46 @@ use util::{byte_utils, events};
 use std::collections::{HashMap, hash_map, HashSet};
 use std::sync::{Arc,Mutex};
 use std::{hash,cmp, mem};
+use std::ops::Deref;
+
+/// An update generated by the underlying Channel itself which contains some new information the
+/// ChannelMonitor should be made aware of.
+#[cfg_attr(test, derive(PartialEq))]
+#[derive(Clone)]
+#[must_use]
+pub struct ChannelMonitorUpdate {
+       pub(super) updates: Vec<ChannelMonitorUpdateStep>,
+       /// The sequence number of this update. Updates *must* be replayed in-order according to this
+       /// sequence number (and updates may panic if they are not). The update_id values are strictly
+       /// increasing and increase by one for each new update.
+       ///
+       /// This sequence number is also used to track up to which points updates which returned
+       /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
+       /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
+       pub update_id: u64,
+}
+
+impl Writeable for ChannelMonitorUpdate {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+               self.update_id.write(w)?;
+               (self.updates.len() as u64).write(w)?;
+               for update_step in self.updates.iter() {
+                       update_step.write(w)?;
+               }
+               Ok(())
+       }
+}
+impl<R: ::std::io::Read> Readable<R> for ChannelMonitorUpdate {
+       fn read(r: &mut R) -> Result<Self, DecodeError> {
+               let update_id: u64 = Readable::read(r)?;
+               let len: u64 = Readable::read(r)?;
+               let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
+               for _ in 0..len {
+                       updates.push(Readable::read(r)?);
+               }
+               Ok(Self { update_id, updates })
+       }
+}
 
 /// An error enum representing a failure to persist a channel monitor update.
 #[derive(Clone)]
@@ -51,13 +91,13 @@ pub enum ChannelMonitorUpdateErr {
        /// our state failed, but is expected to succeed at some point in the future).
        ///
        /// Such a failure will "freeze" a channel, preventing us from revoking old states or
-       /// submitting new commitment transactions to the remote party.
-       /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
-       /// the channel to an operational state.
+       /// submitting new commitment transactions to the remote party. Once the update(s) which failed
+       /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
+       /// restore the channel to an operational state.
        ///
-       /// Note that continuing to operate when no copy of the updated ChannelMonitor could be
-       /// persisted is unsafe - if you failed to store the update on your own local disk you should
-       /// instead return PermanentFailure to force closure of the channel ASAP.
+       /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
+       /// you return a TemporaryFailure you must ensure that it is written to disk safely before
+       /// writing out the latest ChannelManager state.
        ///
        /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
        /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
@@ -68,8 +108,15 @@ pub enum ChannelMonitorUpdateErr {
        /// been "frozen".
        ///
        /// Note that even if updates made after TemporaryFailure succeed you must still call
-       /// test_restore_channel_monitor to ensure you have the latest monitor and re-enable normal
-       /// channel operation.
+       /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
+       /// operation.
+       ///
+       /// Note that the update being processed here will not be replayed for you when you call
+       /// ChannelManager::channel_monitor_updated, so you must store the update itself along
+       /// with the persisted ChannelMonitor on your own local disk prior to returning a
+       /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
+       /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
+       /// reload-time.
        ///
        /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
        /// remote location (with local copies persisted immediately), it is anticipated that all
@@ -84,24 +131,26 @@ pub enum ChannelMonitorUpdateErr {
 }
 
 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
-/// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::insert_combine this
-/// means you tried to merge two monitors for different channels or for a channel which was
-/// restored from a backup and then generated new commitment updates.
+/// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
+/// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
+/// corrupted.
 /// Contains a human-readable error message.
 #[derive(Debug)]
 pub struct MonitorUpdateError(pub &'static str);
 
 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
 /// forward channel and from which info are needed to update HTLC in a backward channel.
+#[derive(Clone, PartialEq)]
 pub struct HTLCUpdate {
        pub(super) payment_hash: PaymentHash,
        pub(super) payment_preimage: Option<PaymentPreimage>,
        pub(super) source: HTLCSource
 }
+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
+/// events to it, while also taking any add/update_monitor events and passing them to some remote
 /// server(s).
 ///
 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
@@ -115,7 +164,7 @@ pub struct HTLCUpdate {
 /// 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 or updates a monitor for the given `funding_txo`.
+       /// 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
@@ -126,12 +175,30 @@ pub trait ManyChannelMonitor<ChanSigner: ChannelKeys>: Send + Sync {
        /// 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_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr>;
+       /// 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 backward
-       fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate>;
+       /// 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
@@ -145,28 +212,28 @@ pub trait ManyChannelMonitor<ChanSigner: ChannelKeys>: Send + Sync {
 ///
 /// If you're using this for local monitoring of your own channels, you probably want to use
 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
-pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys> {
+pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref> where T::Target: BroadcasterInterface {
        #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
        pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
        #[cfg(not(test))]
        monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
        chain_monitor: Arc<ChainWatchInterface>,
-       broadcaster: Arc<BroadcasterInterface>,
+       broadcaster: T,
        pending_events: Mutex<Vec<events::Event>>,
-       pending_htlc_updated: Mutex<HashMap<PaymentHash, Vec<(HTLCSource, Option<PaymentPreimage>)>>>,
        logger: Arc<Logger>,
        fee_estimator: Arc<FeeEstimator>
 }
 
-impl<'a, Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys> ChainListener for SimpleManyChannelMonitor<Key, ChanSigner> {
+impl<'a, Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send> ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T>
+       where T::Target: BroadcasterInterface
+{
        fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
                let block_hash = header.bitcoin_hash();
                let mut new_events: Vec<events::Event> = Vec::with_capacity(0);
-               let mut htlc_updated_infos = Vec::new();
                {
                        let mut monitors = self.monitors.lock().unwrap();
                        for monitor in monitors.values_mut() {
-                               let (txn_outputs, spendable_outputs, mut htlc_updated) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator);
+                               let (txn_outputs, spendable_outputs) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator);
                                if spendable_outputs.len() > 0 {
                                        new_events.push(events::Event::SpendableOutputs {
                                                outputs: spendable_outputs,
@@ -178,35 +245,6 @@ impl<'a, Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys> ChainListen
                                                self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
                                        }
                                }
-                               htlc_updated_infos.append(&mut htlc_updated);
-                       }
-               }
-               {
-                       // ChannelManager will just need to fetch pending_htlc_updated and pass state backward
-                       let mut pending_htlc_updated = self.pending_htlc_updated.lock().unwrap();
-                       for htlc in htlc_updated_infos.drain(..) {
-                               match pending_htlc_updated.entry(htlc.2) {
-                                       hash_map::Entry::Occupied(mut e) => {
-                                               // In case of reorg we may have htlc outputs solved in a different way so
-                                               // we prefer to keep claims but don't store duplicate updates for a given
-                                               // (payment_hash, HTLCSource) pair.
-                                               let mut existing_claim = false;
-                                               e.get_mut().retain(|htlc_data| {
-                                                       if htlc.0 == htlc_data.0 {
-                                                               if htlc_data.1.is_some() {
-                                                                       existing_claim = true;
-                                                                       true
-                                                               } else { false }
-                                                       } else { true }
-                                               });
-                                               if !existing_claim {
-                                                       e.get_mut().push((htlc.0, htlc.1));
-                                               }
-                                       }
-                                       hash_map::Entry::Vacant(e) => {
-                                               e.insert(vec![(htlc.0, htlc.1)]);
-                                       }
-                               }
                        }
                }
                let mut pending_events = self.pending_events.lock().unwrap();
@@ -222,16 +260,17 @@ impl<'a, Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys> ChainListen
        }
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys> SimpleManyChannelMonitor<Key, ChanSigner> {
+impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref> SimpleManyChannelMonitor<Key, ChanSigner, T>
+       where T::Target: BroadcasterInterface
+{
        /// Creates a new object which can be used to monitor several channels given the chain
        /// interface with which to register to receive notifications.
-       pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>, logger: Arc<Logger>, feeest: Arc<FeeEstimator>) -> SimpleManyChannelMonitor<Key, ChanSigner> {
+       pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: T, logger: Arc<Logger>, feeest: Arc<FeeEstimator>) -> SimpleManyChannelMonitor<Key, ChanSigner, T> {
                let res = SimpleManyChannelMonitor {
                        monitors: Mutex::new(HashMap::new()),
                        chain_monitor,
                        broadcaster,
                        pending_events: Mutex::new(Vec::new()),
-                       pending_htlc_updated: Mutex::new(HashMap::new()),
                        logger,
                        fee_estimator: feeest,
                };
@@ -240,14 +279,11 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys> Simpl
        }
 
        /// Adds or updates the monitor which monitors the channel referred to by the given key.
-       pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
+       pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
                let mut monitors = self.monitors.lock().unwrap();
-               match monitors.get_mut(&key) {
-                       Some(orig_monitor) => {
-                               log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(monitor.key_storage));
-                               return orig_monitor.insert_combine(monitor);
-                       },
-                       None => {}
+               let entry = match monitors.entry(key) {
+                       hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
+                       hash_map::Entry::Vacant(e) => e,
                };
                match monitor.key_storage {
                        Storage::Local { ref funding_info, .. } => {
@@ -271,36 +307,52 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys> Simpl
                                self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
                        }
                }
-               monitors.insert(key, monitor);
+               entry.insert(monitor);
                Ok(())
        }
+
+       /// Updates the monitor which monitors the channel referred to by the given key.
+       pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
+               let mut monitors = self.monitors.lock().unwrap();
+               match monitors.get_mut(&key) {
+                       Some(orig_monitor) => {
+                               log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor.key_storage));
+                               orig_monitor.update_monitor(update)
+                       },
+                       None => Err(MonitorUpdateError("No such monitor registered"))
+               }
+       }
 }
 
-impl<ChanSigner: ChannelKeys> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner> {
-       fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
-               match self.add_update_monitor_by_key(funding_txo, monitor) {
+impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner, T>
+       where T::Target: BroadcasterInterface
+{
+       fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
+               match self.add_monitor_by_key(funding_txo, monitor) {
                        Ok(_) => Ok(()),
                        Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
                }
        }
 
-       fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate> {
-               let mut updated = self.pending_htlc_updated.lock().unwrap();
-               let mut pending_htlcs_updated = Vec::with_capacity(updated.len());
-               for (k, v) in updated.drain() {
-                       for htlc_data in v {
-                               pending_htlcs_updated.push(HTLCUpdate {
-                                       payment_hash: k,
-                                       payment_preimage: htlc_data.1,
-                                       source: htlc_data.0,
-                               });
-                       }
+       fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
+               match self.update_monitor_by_key(funding_txo, update) {
+                       Ok(_) => Ok(()),
+                       Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
+               }
+       }
+
+       fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {
+               let mut pending_htlcs_updated = Vec::new();
+               for chan in self.monitors.lock().unwrap().values_mut() {
+                       pending_htlcs_updated.append(&mut chan.get_and_clear_pending_htlcs_updated());
                }
                pending_htlcs_updated
        }
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner> {
+impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T>
+       where T::Target: BroadcasterInterface
+{
        fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
                let mut pending_events = self.pending_events.lock().unwrap();
                let mut ret = Vec::new();
@@ -593,6 +645,141 @@ impl<R: ::std::io::Read> Readable<R> for ClaimTxBumpMaterial {
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
+#[cfg_attr(test, derive(PartialEq))]
+#[derive(Clone)]
+pub(super) enum ChannelMonitorUpdateStep {
+       LatestLocalCommitmentTXInfo {
+               // TODO: We really need to not be generating a fully-signed transaction in Channel and
+               // passing it here, we need to hold off so that the ChanSigner can enforce a
+               // only-sign-local-state-for-broadcast once invariant:
+               commitment_tx: LocalCommitmentTransaction,
+               local_keys: chan_utils::TxCreationKeys,
+               feerate_per_kw: u64,
+               htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
+       },
+       LatestRemoteCommitmentTXInfo {
+               unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
+               htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
+               commitment_number: u64,
+               their_revocation_point: PublicKey,
+       },
+       PaymentPreimage {
+               payment_preimage: PaymentPreimage,
+       },
+       CommitmentSecret {
+               idx: u64,
+               secret: [u8; 32],
+       },
+       /// Indicates our channel is likely a stale version, we're closing, but this update should
+       /// allow us to spend what is ours if our counterparty broadcasts their latest state.
+       RescueRemoteCommitmentTXInfo {
+               their_current_per_commitment_point: PublicKey,
+       },
+}
+
+impl Writeable for ChannelMonitorUpdateStep {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+               match self {
+                       &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref local_keys, ref feerate_per_kw, ref htlc_outputs } => {
+                               0u8.write(w)?;
+                               commitment_tx.write(w)?;
+                               local_keys.write(w)?;
+                               feerate_per_kw.write(w)?;
+                               (htlc_outputs.len() as u64).write(w)?;
+                               for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
+                                       output.write(w)?;
+                                       signature.write(w)?;
+                                       source.write(w)?;
+                               }
+                       }
+                       &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
+                               1u8.write(w)?;
+                               unsigned_commitment_tx.write(w)?;
+                               commitment_number.write(w)?;
+                               their_revocation_point.write(w)?;
+                               (htlc_outputs.len() as u64).write(w)?;
+                               for &(ref output, ref source) in htlc_outputs.iter() {
+                                       output.write(w)?;
+                                       match source {
+                                               &None => 0u8.write(w)?,
+                                               &Some(ref s) => {
+                                                       1u8.write(w)?;
+                                                       s.write(w)?;
+                                               },
+                                       }
+                               }
+                       },
+                       &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
+                               2u8.write(w)?;
+                               payment_preimage.write(w)?;
+                       },
+                       &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
+                               3u8.write(w)?;
+                               idx.write(w)?;
+                               secret.write(w)?;
+                       },
+                       &ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { ref their_current_per_commitment_point } => {
+                               4u8.write(w)?;
+                               their_current_per_commitment_point.write(w)?;
+                       },
+               }
+               Ok(())
+       }
+}
+impl<R: ::std::io::Read> Readable<R> for ChannelMonitorUpdateStep {
+       fn read(r: &mut R) -> Result<Self, DecodeError> {
+               match Readable::read(r)? {
+                       0u8 => {
+                               Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
+                                       commitment_tx: Readable::read(r)?,
+                                       local_keys: Readable::read(r)?,
+                                       feerate_per_kw: Readable::read(r)?,
+                                       htlc_outputs: {
+                                               let len: u64 = Readable::read(r)?;
+                                               let mut res = Vec::new();
+                                               for _ in 0..len {
+                                                       res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
+                                               }
+                                               res
+                                       },
+                               })
+                       },
+                       1u8 => {
+                               Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
+                                       unsigned_commitment_tx: Readable::read(r)?,
+                                       commitment_number: Readable::read(r)?,
+                                       their_revocation_point: Readable::read(r)?,
+                                       htlc_outputs: {
+                                               let len: u64 = Readable::read(r)?;
+                                               let mut res = Vec::new();
+                                               for _ in 0..len {
+                                                       res.push((Readable::read(r)?, <Option<HTLCSource> as Readable<R>>::read(r)?.map(|o| Box::new(o))));
+                                               }
+                                               res
+                                       },
+                               })
+                       },
+                       2u8 => {
+                               Ok(ChannelMonitorUpdateStep::PaymentPreimage {
+                                       payment_preimage: Readable::read(r)?,
+                               })
+                       },
+                       3u8 => {
+                               Ok(ChannelMonitorUpdateStep::CommitmentSecret {
+                                       idx: Readable::read(r)?,
+                                       secret: Readable::read(r)?,
+                               })
+                       },
+                       4u8 => {
+                               Ok(ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo {
+                                       their_current_per_commitment_point: Readable::read(r)?,
+                               })
+                       },
+                       _ => Err(DecodeError::InvalidValue),
+               }
+       }
+}
+
 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
 /// on-chain transactions to ensure no loss of funds occurs.
 ///
@@ -600,6 +787,7 @@ const MIN_SERIALIZATION_VERSION: u8 = 1;
 /// information and are actively monitoring the chain.
 #[derive(Clone)]
 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
+       latest_update_id: u64,
        commitment_transaction_number_obscure_factor: u64,
 
        key_storage: Storage<ChanSigner>,
@@ -613,7 +801,7 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        our_to_self_delay: u16,
        their_to_self_delay: Option<u16>,
 
-       old_secrets: [([u8; 32], u64); 49],
+       commitment_secrets: CounterpartyCommitmentSecrets,
        remote_claimable_outpoints: HashMap<Sha256dHash, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
        /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
        /// Nor can we figure out their commitment numbers without the commitment transaction they are
@@ -640,6 +828,8 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
 
        payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
 
+       pending_htlcs_updated: Vec<HTLCUpdate>,
+
        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
@@ -686,14 +876,13 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
 
        // We simply modify last_block_hash in Channel's block_connected so that serialization is
        // consistent but hopefully the users' copy handles block_connected in a consistent way.
-       // (we do *not*, however, update them in insert_combine to ensure any local user copies keep
+       // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
        // their last_block_hash from its state and not based on updated copies that didn't run through
        // the full block_connected).
        pub(crate) last_block_hash: Sha256dHash,
        secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
        logger: Arc<Logger>,
 }
-
 macro_rules! subtract_high_prio_fee {
        ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
                {
@@ -734,7 +923,8 @@ macro_rules! subtract_high_prio_fee {
 /// underlying object
 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
        fn eq(&self, other: &Self) -> bool {
-               if self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
+               if self.latest_update_id != other.latest_update_id ||
+                       self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
                        self.key_storage != other.key_storage ||
                        self.their_htlc_base_key != other.their_htlc_base_key ||
                        self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
@@ -743,6 +933,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                        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.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 ||
                        self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
@@ -750,6 +941,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                        self.current_remote_commitment_number != other.current_remote_commitment_number ||
                        self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
                        self.payment_preimages != other.payment_preimages ||
+                       self.pending_htlcs_updated != other.pending_htlcs_updated ||
                        self.destination_script != other.destination_script ||
                        self.to_remote_rescue != other.to_remote_rescue ||
                        self.pending_claim_requests != other.pending_claim_requests ||
@@ -759,11 +951,6 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                {
                        false
                } else {
-                       for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
-                               if secret != o_secret || idx != o_idx {
-                                       return false
-                               }
-                       }
                        true
                }
        }
@@ -777,6 +964,8 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                writer.write_all(&[SERIALIZATION_VERSION; 1])?;
                writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
 
+               self.latest_update_id.write(writer)?;
+
                // Set in initial Channel-object creation, so should always be set by now:
                U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
 
@@ -844,10 +1033,7 @@ 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.unwrap()))?;
 
-               for &(ref secret, ref idx) in self.old_secrets.iter() {
-                       writer.write_all(secret)?;
-                       writer.write_all(&byte_utils::be64_to_array(*idx))?;
-               }
+               self.commitment_secrets.write(writer)?;
 
                macro_rules! serialize_htlc_in_commitment {
                        ($htlc_output: expr) => {
@@ -938,6 +1124,11 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                        writer.write_all(&payment_preimage.0[..])?;
                }
 
+               writer.write_all(&byte_utils::be64_to_array(self.pending_htlcs_updated.len() as u64))?;
+               for data in self.pending_htlcs_updated.iter() {
+                       data.write(writer)?;
+               }
+
                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 {
@@ -1021,32 +1212,45 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
 }
 
 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
-       pub(super) fn new(keys: ChanSigner, funding_key: &SecretKey, revocation_base_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, payment_base_key: &SecretKey, shutdown_pubkey: &PublicKey, our_to_self_delay: u16, destination_script: Script, logger: Arc<Logger>) -> 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,
+                       commitment_transaction_number_obscure_factor: u64,
+                       logger: Arc<Logger>) -> ChannelMonitor<ChanSigner> {
+
+               assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
+               let funding_key = keys.funding_key().clone();
+               let revocation_base_key = keys.revocation_base_key().clone();
+               let htlc_base_key = keys.htlc_base_key().clone();
+               let delayed_payment_base_key = keys.delayed_payment_base_key().clone();
+               let payment_base_key = keys.payment_base_key().clone();
                ChannelMonitor {
-                       commitment_transaction_number_obscure_factor: 0,
+                       latest_update_id: 0,
+                       commitment_transaction_number_obscure_factor,
 
                        key_storage: Storage::Local {
                                keys,
-                               funding_key: funding_key.clone(),
-                               revocation_base_key: revocation_base_key.clone(),
-                               htlc_base_key: htlc_base_key.clone(),
-                               delayed_payment_base_key: delayed_payment_base_key.clone(),
-                               payment_base_key: payment_base_key.clone(),
+                               funding_key,
+                               revocation_base_key,
+                               htlc_base_key,
+                               delayed_payment_base_key,
+                               payment_base_key,
                                shutdown_pubkey: shutdown_pubkey.clone(),
-                               funding_info: None,
+                               funding_info: Some(funding_info),
                                current_remote_commitment_txid: None,
                                prev_remote_commitment_txid: None,
                        },
-                       their_htlc_base_key: None,
-                       their_delayed_payment_base_key: None,
-                       funding_redeemscript: None,
-                       channel_value_satoshis: None,
+                       their_htlc_base_key: Some(their_htlc_base_key.clone()),
+                       their_delayed_payment_base_key: Some(their_delayed_payment_base_key.clone()),
+                       funding_redeemscript: Some(funding_redeemscript),
+                       channel_value_satoshis: Some(channel_value_satoshis),
                        their_cur_revocation_points: None,
 
                        our_to_self_delay: our_to_self_delay,
-                       their_to_self_delay: None,
+                       their_to_self_delay: Some(their_to_self_delay),
 
-                       old_secrets: [([0; 32], 1 << 48); 49],
+                       commitment_secrets: CounterpartyCommitmentSecrets::new(),
                        remote_claimable_outpoints: HashMap::new(),
                        remote_commitment_txn_on_chain: HashMap::new(),
                        remote_hash_commitment_number: HashMap::new(),
@@ -1056,7 +1260,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        current_remote_commitment_number: 1 << 48,
 
                        payment_preimages: HashMap::new(),
-                       destination_script: destination_script,
+                       pending_htlcs_updated: Vec::new(),
+
+                       destination_script: destination_script.clone(),
                        to_remote_rescue: None,
 
                        pending_claim_requests: HashMap::new(),
@@ -1111,44 +1317,13 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                current_height + 15
        }
 
-       #[inline]
-       fn place_secret(idx: u64) -> u8 {
-               for i in 0..48 {
-                       if idx & (1 << i) == (1 << i) {
-                               return i
-                       }
-               }
-               48
-       }
-
-       #[inline]
-       fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
-               let mut res: [u8; 32] = secret;
-               for i in 0..bits {
-                       let bitpos = bits - 1 - i;
-                       if idx & (1 << bitpos) == (1 << bitpos) {
-                               res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
-                               res = Sha256::hash(&res).into_inner();
-                       }
-               }
-               res
-       }
-
        /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
        /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
        /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
        pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
-               let pos = ChannelMonitor::<ChanSigner>::place_secret(idx);
-               for i in 0..pos {
-                       let (old_secret, old_idx) = self.old_secrets[i as usize];
-                       if ChannelMonitor::<ChanSigner>::derive_secret(secret, pos, old_idx) != old_secret {
-                               return Err(MonitorUpdateError("Previous secret did not match new one"));
-                       }
-               }
-               if self.get_min_seen_secret() <= idx {
-                       return Ok(());
+               if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
+                       return Err(MonitorUpdateError("Previous secret did not match new one"));
                }
-               self.old_secrets[pos as usize] = (secret, idx);
 
                // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
                // events for now-revoked/fulfilled HTLCs.
@@ -1260,8 +1435,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        /// 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.
-       pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) {
-               assert!(self.their_to_self_delay.is_some());
+       pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
+               if self.their_to_self_delay.is_none() {
+                       return Err(MonitorUpdateError("Got a local commitment tx info update before we'd set basic information about the channel"));
+               }
                self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
                self.current_local_signed_commitment_tx = Some(LocalSignedTx {
                        txid: commitment_tx.txid(),
@@ -1274,6 +1451,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        feerate_per_kw,
                        htlc_outputs,
                });
+               Ok(())
        }
 
        /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
@@ -1282,106 +1460,56 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
        }
 
-       /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
-       /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
-       /// chain for new blocks/transactions.
-       pub fn insert_combine(&mut self, mut other: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
-               match self.key_storage {
-                       Storage::Local { ref funding_info, .. } => {
-                               if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
-                               let our_funding_info = funding_info;
-                               if let Storage::Local { ref funding_info, .. } = other.key_storage {
-                                       if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
-                                       // We should be able to compare the entire funding_txo, but in fuzztarget it's trivially
-                                       // easy to collide the funding_txo hash and have a different scriptPubKey.
-                                       if funding_info.as_ref().unwrap().0 != our_funding_info.as_ref().unwrap().0 {
-                                               return Err(MonitorUpdateError("Funding transaction outputs are not identical!"));
-                                       }
-                               } else {
-                                       return Err(MonitorUpdateError("Try to combine a Local monitor with a Watchtower one !"));
-                               }
-                       },
-                       Storage::Watchtower { .. } => {
-                               if let Storage::Watchtower { .. } = other.key_storage {
-                                       unimplemented!();
-                               } else {
-                                       return Err(MonitorUpdateError("Try to combine a Watchtower monitor with a Local one !"));
-                               }
-                       },
-               }
-               let other_min_secret = other.get_min_seen_secret();
-               let our_min_secret = self.get_min_seen_secret();
-               if our_min_secret > other_min_secret {
-                       self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap())?;
-               }
-               if let Some(ref local_tx) = self.current_local_signed_commitment_tx {
-                       if let Some(ref other_local_tx) = other.current_local_signed_commitment_tx {
-                               let our_commitment_number = 0xffffffffffff - ((((local_tx.tx.without_valid_witness().input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.without_valid_witness().lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
-                               let other_commitment_number = 0xffffffffffff - ((((other_local_tx.tx.without_valid_witness().input[0].sequence as u64 & 0xffffff) << 3*8) | (other_local_tx.tx.without_valid_witness().lock_time as u64 & 0xffffff)) ^ other.commitment_transaction_number_obscure_factor);
-                               if our_commitment_number >= other_commitment_number {
-                                       self.key_storage = other.key_storage;
-                               }
-                       }
-               }
-               // TODO: We should use current_remote_commitment_number and the commitment number out of
-               // local transactions to decide how to merge
-               if our_min_secret >= other_min_secret {
-                       self.their_cur_revocation_points = other.their_cur_revocation_points;
-                       for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
-                               self.remote_claimable_outpoints.insert(txid, htlcs);
-                       }
-                       if let Some(local_tx) = other.prev_local_signed_commitment_tx {
-                               self.prev_local_signed_commitment_tx = Some(local_tx);
-                       }
-                       if let Some(local_tx) = other.current_local_signed_commitment_tx {
-                               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);
+       /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
+       pub(super) fn update_monitor_ooo(&mut self, mut updates: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
+               for update in updates.updates.drain(..) {
+                       match update {
+                               ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
+                                       self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
+                               ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
+                                       self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
+                               ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
+                                       self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
+                               ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
+                                       self.provide_secret(idx, secret)?,
+                               ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
+                                       self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
+                       }
+               }
+               self.latest_update_id = updates.update_id;
                Ok(())
        }
 
-       /// Allows this monitor to scan only for transactions which are applicable. Note that this is
-       /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
-       /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
-       /// provides slightly better privacy.
-       /// It's the responsibility of the caller to register outpoint and script with passing the former
-       /// value as key to add_update_monitor.
-       pub(super) fn set_funding_info(&mut self, new_funding_info: (OutPoint, Script)) {
-               match self.key_storage {
-                       Storage::Local { ref mut funding_info, .. } => {
-                               *funding_info = Some(new_funding_info);
-                       },
-                       Storage::Watchtower { .. } => {
-                               panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
-                       }
-               }
-       }
-
-       /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
-       /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
-       pub(super) fn set_basic_channel_info(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey, their_to_self_delay: u16, funding_redeemscript: Script, channel_value_satoshis: u64, commitment_transaction_number_obscure_factor: u64) {
-               self.their_htlc_base_key = Some(their_htlc_base_key.clone());
-               self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
-               self.their_to_self_delay = Some(their_to_self_delay);
-               self.funding_redeemscript = Some(funding_redeemscript);
-               self.channel_value_satoshis = Some(channel_value_satoshis);
-               assert!(commitment_transaction_number_obscure_factor < (1 << 48));
-               self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
+       /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
+       /// itself.
+       ///
+       /// panics if the given update is not the next update by update_id.
+       pub fn update_monitor(&mut self, mut updates: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
+               if self.latest_update_id + 1 != updates.update_id {
+                       panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
+               }
+               for update in updates.updates.drain(..) {
+                       match update {
+                               ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
+                                       self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
+                               ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
+                                       self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
+                               ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
+                                       self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
+                               ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
+                                       self.provide_secret(idx, secret)?,
+                               ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
+                                       self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
+                       }
+               }
+               self.latest_update_id = updates.update_id;
+               Ok(())
        }
 
-       pub(super) fn unset_funding_info(&mut self) {
-               match self.key_storage {
-                       Storage::Local { ref mut funding_info, .. } => {
-                               *funding_info = None;
-                       },
-                       Storage::Watchtower { .. } => {
-                               panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
-                       },
-               }
+       /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
+       /// ChannelMonitor.
+       pub fn get_latest_update_id(&self) -> u64 {
+               self.latest_update_id
        }
 
        /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
@@ -1419,26 +1547,21 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                res
        }
 
+       /// Get the list of HTLCs who's status has been updated on chain. This should be called by
+       /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_htlcs_updated().
+       pub fn get_and_clear_pending_htlcs_updated(&mut self) -> Vec<HTLCUpdate> {
+               let mut ret = Vec::new();
+               mem::swap(&mut ret, &mut self.pending_htlcs_updated);
+               ret
+       }
+
        /// Can only fail if idx is < get_min_seen_secret
        pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
-               for i in 0..self.old_secrets.len() {
-                       if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
-                               return Some(ChannelMonitor::<ChanSigner>::derive_secret(self.old_secrets[i].0, i as u8, idx))
-                       }
-               }
-               assert!(idx < self.get_min_seen_secret());
-               None
+               self.commitment_secrets.get_secret(idx)
        }
 
        pub(super) fn get_min_seen_secret(&self) -> u64 {
-               //TODO This can be optimized?
-               let mut min = 1 << 48;
-               for &(_, idx) in self.old_secrets.iter() {
-                       if idx < min {
-                               min = idx;
-                       }
-               }
-               min
+               self.commitment_secrets.get_min_seen_secret()
        }
 
        pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
@@ -2402,7 +2525,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
        /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
        /// on-chain.
-       fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface, fee_estimator: &FeeEstimator)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>, Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)>) {
+       fn block_connected<B: Deref>(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: B, fee_estimator: &FeeEstimator)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>)
+               where B::Target: BroadcasterInterface
+       {
                for tx in txn_matched {
                        let mut output_val = 0;
                        for out in tx.output.iter() {
@@ -2415,7 +2540,6 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                log_trace!(self, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
                let mut watch_outputs = Vec::new();
                let mut spendable_outputs = Vec::new();
-               let mut htlc_updated = Vec::new();
                let mut bump_candidates = HashSet::new();
                for tx in txn_matched {
                        if tx.input.len() == 1 {
@@ -2474,10 +2598,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
                        // can also be resolved in a few other ways which can have more than one output. Thus,
                        // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
-                       let mut updated = self.is_resolving_htlc_output(&tx, height);
-                       if updated.len() > 0 {
-                               htlc_updated.append(&mut updated);
-                       }
+                       self.is_resolving_htlc_output(&tx, height);
 
                        // Scan all input to verify is one of the outpoint spent is of interest for us
                        let mut claimed_outputs_material = Vec::new();
@@ -2600,7 +2721,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                        },
                                        OnchainEvent::HTLCUpdate { htlc_update } => {
                                                log_trace!(self, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
-                                               htlc_updated.push((htlc_update.0, None, htlc_update.1));
+                                               self.pending_htlcs_updated.push(HTLCUpdate {
+                                                       payment_hash: htlc_update.1,
+                                                       payment_preimage: None,
+                                                       source: htlc_update.0,
+                                               });
                                        },
                                        OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
                                                self.claimable_outpoints.remove(&outpoint);
@@ -2632,10 +2757,12 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                for &(ref txid, ref output_scripts) in watch_outputs.iter() {
                        self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
                }
-               (watch_outputs, spendable_outputs, htlc_updated)
+               (watch_outputs, spendable_outputs)
        }
 
-       fn block_disconnected(&mut self, height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface, fee_estimator: &FeeEstimator) {
+       fn block_disconnected<B: Deref>(&mut self, height: u32, block_hash: &Sha256dHash, broadcaster: B, fee_estimator: &FeeEstimator)
+               where B::Target: BroadcasterInterface
+       {
                log_trace!(self, "Block {} at height {} disconnected", block_hash, height);
                let mut bump_candidates = HashMap::new();
                if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
@@ -2752,9 +2879,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
        /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
        /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
-       fn is_resolving_htlc_output(&mut self, tx: &Transaction, height: u32) -> Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)> {
-               let mut htlc_updated = Vec::new();
-
+       fn is_resolving_htlc_output(&mut self, tx: &Transaction, height: u32) {
                'outer_loop: for input in &tx.input {
                        let mut payment_data = None;
                        let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
@@ -2854,10 +2979,18 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                let mut payment_preimage = PaymentPreimage([0; 32]);
                                if accepted_preimage_claim {
                                        payment_preimage.0.copy_from_slice(&input.witness[3]);
-                                       htlc_updated.push((source, Some(payment_preimage), payment_hash));
+                                       self.pending_htlcs_updated.push(HTLCUpdate {
+                                               source,
+                                               payment_preimage: Some(payment_preimage),
+                                               payment_hash
+                                       });
                                } else if offered_preimage_claim {
                                        payment_preimage.0.copy_from_slice(&input.witness[1]);
-                                       htlc_updated.push((source, Some(payment_preimage), payment_hash));
+                                       self.pending_htlcs_updated.push(HTLCUpdate {
+                                               source,
+                                               payment_preimage: 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 + ANTI_REORG_DELAY - 1);
                                        match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
@@ -2880,7 +3013,6 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                }
                        }
                }
-               htlc_updated
        }
 
        /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
@@ -3041,6 +3173,7 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                        return Err(DecodeError::UnknownVersion);
                }
 
+               let latest_update_id: u64 = Readable::read(reader)?;
                let commitment_transaction_number_obscure_factor = <U48 as Readable<R>>::read(reader)?.0;
 
                let key_storage = match <u8 as Readable<R>>::read(reader)? {
@@ -3100,11 +3233,7 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                let our_to_self_delay: u16 = Readable::read(reader)?;
                let their_to_self_delay: Option<u16> = Some(Readable::read(reader)?);
 
-               let mut old_secrets = [([0; 32], 1 << 48); 49];
-               for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
-                       *secret = Readable::read(reader)?;
-                       *idx = Readable::read(reader)?;
-               }
+               let commitment_secrets = Readable::read(reader)?;
 
                macro_rules! read_htlc_in_commitment {
                        () => {
@@ -3221,6 +3350,12 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                        }
                }
 
+               let pending_htlcs_updated_len: u64 = Readable::read(reader)?;
+               let mut pending_htlcs_updated = Vec::with_capacity(cmp::min(pending_htlcs_updated_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
+               for _ in 0..pending_htlcs_updated_len {
+                       pending_htlcs_updated.push(Readable::read(reader)?);
+               }
+
                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)? {
@@ -3299,6 +3434,7 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                }
 
                Ok((last_block_hash.clone(), ChannelMonitor {
+                       latest_update_id,
                        commitment_transaction_number_obscure_factor,
 
                        key_storage,
@@ -3311,7 +3447,7 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                        our_to_self_delay,
                        their_to_self_delay,
 
-                       old_secrets,
+                       commitment_secrets,
                        remote_claimable_outpoints,
                        remote_commitment_txn_on_chain,
                        remote_hash_commitment_number,
@@ -3321,6 +3457,7 @@ impl<R: ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
                        current_remote_commitment_number,
 
                        payment_preimages,
+                       pending_htlcs_updated,
 
                        destination_script,
                        to_remote_rescue,
@@ -3352,6 +3489,7 @@ mod tests {
        use bitcoin_hashes::sha256d::Hash as Sha256dHash;
        use bitcoin_hashes::hex::FromHex;
        use hex;
+       use chain::transaction::OutPoint;
        use ln::channelmanager::{PaymentPreimage, PaymentHash};
        use ln::channelmonitor::{ChannelMonitor, InputDescriptors};
        use ln::chan_utils;
@@ -3363,373 +3501,6 @@ mod tests {
        use std::sync::Arc;
        use chain::keysinterface::InMemoryChannelKeys;
 
-
-       #[test]
-       fn test_per_commitment_storage() {
-               // Test vectors from BOLT 3:
-               let mut secrets: Vec<[u8; 32]> = Vec::new();
-               let mut monitor: ChannelMonitor<InMemoryChannelKeys>;
-               let secp_ctx = Secp256k1::new();
-               let logger = Arc::new(TestLogger::new());
-
-               macro_rules! test_secrets {
-                       () => {
-                               let mut idx = 281474976710655;
-                               for secret in secrets.iter() {
-                                       assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
-                                       idx -= 1;
-                               }
-                               assert_eq!(monitor.get_min_seen_secret(), idx + 1);
-                               assert!(monitor.get_secret(idx).is_none());
-                       };
-               }
-
-               let keys = InMemoryChannelKeys::new(
-                       &secp_ctx,
-                       SecretKey::from_slice(&[41; 32]).unwrap(),
-                       SecretKey::from_slice(&[41; 32]).unwrap(),
-                       SecretKey::from_slice(&[41; 32]).unwrap(),
-                       SecretKey::from_slice(&[41; 32]).unwrap(),
-                       SecretKey::from_slice(&[41; 32]).unwrap(),
-                       [41; 32],
-                       0,
-               );
-
-               {
-                       // insert_secret correct sequence
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
-                       monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
-                       monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
-                       monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-               }
-
-               {
-                       // insert_secret #1 incorrect
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #2 incorrect (#1 derived from incorrect)
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #3 incorrect
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #4 incorrect (1,2,3 derived from incorrect)
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
-                       monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
-                       monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #5 incorrect
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #6 incorrect (5 derived from incorrect)
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
-                       monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
-                       monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #7 incorrect
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
-                       monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
-                       monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-
-               {
-                       // insert_secret #8 incorrect
-                       monitor = ChannelMonitor::new(keys.clone(), &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
-                       secrets.clear();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
-                       monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
-                       monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
-                       monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
-                       monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
-                       monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
-                       monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
-                       monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
-                       test_secrets!();
-
-                       secrets.push([0; 32]);
-                       secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
-                       assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
-                                       "Previous secret did not match new one");
-               }
-       }
-
        #[test]
        fn test_prune_preimages() {
                let secp_ctx = Secp256k1::new();
@@ -3811,10 +3582,16 @@ mod tests {
 
                // Prune with one old state and a local commitment tx holding a few overlaps with the
                // old state.
-               let mut monitor = ChannelMonitor::new(keys, &SecretKey::from_slice(&[41; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
+               let mut monitor = ChannelMonitor::new(keys,
+                       &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
+                       (OutPoint { txid: Sha256dHash::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
+                       &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
+                       &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
+                       0, Script::new(), 46, 0, logger.clone());
+
                monitor.their_to_self_delay = Some(10);
 
-               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
+               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10])).unwrap();
                monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
                monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
                monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
@@ -3840,7 +3617,7 @@ mod tests {
 
                // Now update local commitment tx info, pruning only element 18 as we still care about the
                // previous commitment tx's preimages too
-               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
+               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5])).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                monitor.provide_secret(281474976710653, secret.clone()).unwrap();
                assert_eq!(monitor.payment_preimages.len(), 12);
@@ -3848,7 +3625,7 @@ mod tests {
                test_preimages_exist!(&preimages[18..20], monitor);
 
                // But if we do it again, we'll prune 5-10
-               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
+               monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3])).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                monitor.provide_secret(281474976710652, secret.clone()).unwrap();
                assert_eq!(monitor.payment_preimages.len(), 5);