Enable monitor to rebuild initial counterparty commitment tx
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index 313d522fa4c94b76b548208d6afcccac97ad2416..0c207fa8b17429b32e31f1eda65ea0270dcdad82 100644 (file)
@@ -33,34 +33,32 @@ use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
 use bitcoin::secp256k1::{SecretKey, PublicKey};
 use bitcoin::secp256k1;
 
+use crate::ln::channel::INITIAL_COMMITMENT_NUMBER;
 use crate::ln::{PaymentHash, PaymentPreimage};
 use crate::ln::msgs::DecodeError;
 use crate::ln::chan_utils;
-use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction};
-use crate::ln::channelmanager::HTLCSource;
+use crate::ln::chan_utils::{CommitmentTransaction, CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction, TxCreationKeys};
+use crate::ln::channelmanager::{HTLCSource, SentHTLCId};
 use crate::chain;
 use crate::chain::{BestBlock, WatchedOutput};
 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
 use crate::chain::transaction::{OutPoint, TransactionData};
-use crate::chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
-#[cfg(anchors)]
-use crate::chain::onchaintx::ClaimEvent;
-use crate::chain::onchaintx::OnchainTxHandler;
+use crate::sign::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
+use crate::chain::onchaintx::{ClaimEvent, OnchainTxHandler};
 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
 use crate::chain::Filter;
 use crate::util::logger::Logger;
-use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48, OptionDeserWrapper};
+use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
 use crate::util::byte_utils;
-use crate::util::events::Event;
-#[cfg(anchors)]
-use crate::util::events::{AnchorDescriptor, BumpTransactionEvent};
+use crate::events::{Event, EventHandler};
+use crate::events::bump_transaction::{ChannelDerivationParameters, AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
 
 use crate::prelude::*;
 use core::{cmp, mem};
 use crate::io::{self, Error};
 use core::convert::TryInto;
 use core::ops::Deref;
-use crate::sync::Mutex;
+use crate::sync::{Mutex, LockTestExt};
 
 /// An update generated by the underlying channel itself which contains some new information the
 /// [`ChannelMonitor`] should be made aware of.
@@ -69,34 +67,36 @@ use crate::sync::Mutex;
 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
-#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 #[must_use]
 pub struct ChannelMonitorUpdate {
        pub(crate) 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, with one exception specified below.
+       /// increasing and increase by one for each new update, with two exceptions specified below.
        ///
        /// This sequence number is also used to track up to which points updates which returned
        /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
        /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
        ///
-       /// The only instance where update_id values are not strictly increasing is the case where we
-       /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
-       /// its docs for more details.
+       /// The only instances we allow where update_id values are not strictly increasing have a
+       /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
+       /// will force close the channel by broadcasting the latest commitment transaction or
+       /// special post-force-close updates, like providing preimages necessary to claim outputs on the
+       /// broadcast commitment transaction. See its docs for more details.
        ///
        /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
        pub update_id: u64,
 }
 
-/// If:
-///    (1) a channel has been force closed and
-///    (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
-///        this channel's (the backward link's) broadcasted commitment transaction
-/// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
-/// with the update providing said payment preimage. No other update types are allowed after
-/// force-close.
+/// The update ID used for a [`ChannelMonitorUpdate`] that is either:
+///
+///    (1) attempting to force close the channel by broadcasting our latest commitment transaction or
+///    (2) providing a preimage (after the channel has been force closed) from a forward link that
+///            allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
+///            commitment transaction.
+///
+/// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
 
 impl Writeable for ChannelMonitorUpdate {
@@ -263,10 +263,9 @@ impl_writeable_tlv_based!(HolderSignedTx, {
        (8, delayed_payment_key, required),
        (10, per_commitment_point, required),
        (12, feerate_per_kw, required),
-       (14, htlc_outputs, vec_type)
+       (14, htlc_outputs, required_vec)
 });
 
-#[cfg(anchors)]
 impl HolderSignedTx {
        fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
                self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
@@ -282,7 +281,7 @@ impl HolderSignedTx {
 
 /// We use this to track static counterparty commitment transaction data and to generate any
 /// justice or 2nd-stage preimage/timeout transactions.
-#[derive(PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 struct CounterpartyCommitmentParameters {
        counterparty_delayed_payment_base_key: PublicKey,
        counterparty_htlc_base_key: PublicKey,
@@ -314,8 +313,8 @@ impl Readable for CounterpartyCommitmentParameters {
                                }
                        }
 
-                       let mut counterparty_delayed_payment_base_key = OptionDeserWrapper(None);
-                       let mut counterparty_htlc_base_key = OptionDeserWrapper(None);
+                       let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
+                       let mut counterparty_htlc_base_key = RequiredWrapper(None);
                        let mut on_counterparty_tx_csv: u16 = 0;
                        read_tlv_fields!(r, {
                                (0, counterparty_delayed_payment_base_key, required),
@@ -336,7 +335,7 @@ impl Readable for CounterpartyCommitmentParameters {
 /// observed, as well as the transaction causing it.
 ///
 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
-#[derive(PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 struct OnchainEventEntry {
        txid: Txid,
        height: u32,
@@ -379,7 +378,7 @@ type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
 
 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
-#[derive(PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 enum OnchainEvent {
        /// An outbound HTLC failing after a transaction is confirmed. Used
        ///  * when an outbound HTLC output is spent by us after the HTLC timed out
@@ -454,19 +453,15 @@ impl MaybeReadable for OnchainEventEntry {
                let mut transaction = None;
                let mut block_hash = None;
                let mut height = 0;
-               let mut event = None;
+               let mut event = UpgradableRequired(None);
                read_tlv_fields!(reader, {
                        (0, txid, required),
                        (1, transaction, option),
                        (2, height, required),
                        (3, block_hash, option),
-                       (4, event, ignorable),
+                       (4, event, upgradable_required),
                });
-               if let Some(ev) = event {
-                       Ok(Some(Self { txid, transaction, height, block_hash, event: ev }))
-               } else {
-                       Ok(None)
-               }
+               Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
        }
 }
 
@@ -492,18 +487,25 @@ impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 
 );
 
-#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 pub(crate) enum ChannelMonitorUpdateStep {
        LatestHolderCommitmentTXInfo {
                commitment_tx: HolderCommitmentTransaction,
+               /// Note that LDK after 0.0.115 supports this only containing dust HTLCs (implying the
+               /// `Signature` field is never filled in). At that point, non-dust HTLCs are implied by the
+               /// HTLC fields in `commitment_tx` and the sources passed via `nondust_htlc_sources`.
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
+               claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
+               nondust_htlc_sources: Vec<HTLCSource>,
        },
        LatestCounterpartyCommitmentTXInfo {
                commitment_txid: Txid,
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
                commitment_number: u64,
                their_per_commitment_point: PublicKey,
+               feerate_per_kw: Option<u32>,
+               to_broadcaster_value_sat: Option<u64>,
+               to_countersignatory_value_sat: Option<u64>,
        },
        PaymentPreimage {
                payment_preimage: PaymentPreimage,
@@ -540,13 +542,18 @@ impl ChannelMonitorUpdateStep {
 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
        (0, LatestHolderCommitmentTXInfo) => {
                (0, commitment_tx, required),
-               (2, htlc_outputs, vec_type),
+               (1, claimed_htlcs, optional_vec),
+               (2, htlc_outputs, required_vec),
+               (4, nondust_htlc_sources, optional_vec),
        },
        (1, LatestCounterpartyCommitmentTXInfo) => {
                (0, commitment_txid, required),
+               (1, feerate_per_kw, option),
                (2, commitment_number, required),
+               (3, to_broadcaster_value_sat, option),
                (4, their_per_commitment_point, required),
-               (6, htlc_outputs, vec_type),
+               (5, to_countersignatory_value_sat, option),
+               (6, htlc_outputs, required_vec),
        },
        (2, PaymentPreimage) => {
                (0, payment_preimage, required),
@@ -576,14 +583,14 @@ pub enum Balance {
        ClaimableOnChannelClose {
                /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
                /// required to do so.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
        },
        /// The channel has been closed, and the given balance is ours but awaiting confirmations until
        /// we consider it spendable.
        ClaimableAwaitingConfirmations {
                /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
                /// were spent in broadcasting the transaction.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
                /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
                /// amount.
                confirmation_height: u32,
@@ -598,10 +605,14 @@ pub enum Balance {
        ContentiousClaimable {
                /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
                /// required to do so.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
                /// The height at which the counterparty may be able to claim the balance if we have not
                /// done so.
                timeout_height: u32,
+               /// The payment hash that locks this HTLC.
+               payment_hash: PaymentHash,
+               /// The preimage that can be used to claim this HTLC.
+               payment_preimage: PaymentPreimage,
        },
        /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
        /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
@@ -609,10 +620,12 @@ pub enum Balance {
        MaybeTimeoutClaimableHTLC {
                /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
                /// which will be required to do so.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
                /// The height at which we will be able to claim the balance if our counterparty has not
                /// done so.
                claimable_height: u32,
+               /// The payment hash whose preimage our counterparty needs to claim this HTLC.
+               payment_hash: PaymentHash,
        },
        /// HTLCs which we received from our counterparty which are claimable with a preimage which we
        /// do not currently have. This will only be claimable if we receive the preimage from the node
@@ -620,10 +633,12 @@ pub enum Balance {
        MaybePreimageClaimableHTLC {
                /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
                /// which will be required to do so.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
                /// The height at which our counterparty will be able to claim the balance if we have not
                /// yet received the preimage and claimed it ourselves.
                expiry_height: u32,
+               /// The payment hash whose preimage we need to claim this HTLC.
+               payment_hash: PaymentHash,
        },
        /// The channel has been closed, and our counterparty broadcasted a revoked commitment
        /// transaction.
@@ -635,12 +650,33 @@ pub enum Balance {
                ///
                /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
                /// were already spent.
-               claimable_amount_satoshis: u64,
+               amount_satoshis: u64,
        },
 }
 
+impl Balance {
+       /// The amount claimable, in satoshis. This excludes balances that we are unsure if we are able
+       /// to claim, this is because we are waiting for a preimage or for a timeout to expire. For more
+       /// information on these balances see [`Balance::MaybeTimeoutClaimableHTLC`] and
+       /// [`Balance::MaybePreimageClaimableHTLC`].
+       ///
+       /// On-chain fees required to claim the balance are not included in this amount.
+       pub fn claimable_amount_satoshis(&self) -> u64 {
+               match self {
+                       Balance::ClaimableOnChannelClose { amount_satoshis, .. }|
+                       Balance::ClaimableAwaitingConfirmations { amount_satoshis, .. }|
+                       Balance::ContentiousClaimable { amount_satoshis, .. }|
+                       Balance::CounterpartyRevokedOutputClaimable { amount_satoshis, .. }
+                               => *amount_satoshis,
+                       Balance::MaybeTimeoutClaimableHTLC { .. }|
+                       Balance::MaybePreimageClaimableHTLC { .. }
+                               => 0,
+               }
+       }
+}
+
 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
-#[derive(PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 struct IrrevocablyResolvedHTLC {
        commitment_tx_output_idx: Option<u32>,
        /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
@@ -696,24 +732,27 @@ impl Readable for IrrevocablyResolvedHTLC {
 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
 /// information and are actively monitoring the chain.
 ///
-/// Pending Events or updated HTLCs which have not yet been read out by
-/// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
-/// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
-/// gotten are fully handled before re-serializing the new state.
-///
 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
 /// returned block hash and the the current chain and then reconnecting blocks to get to the
 /// best chain) upon deserializing the object!
-pub struct ChannelMonitor<Signer: Sign> {
+pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
        #[cfg(test)]
        pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
        #[cfg(not(test))]
-       inner: Mutex<ChannelMonitorImpl<Signer>>,
+       pub(super) inner: Mutex<ChannelMonitorImpl<Signer>>,
+}
+
+impl<Signer: WriteableEcdsaChannelSigner> Clone for ChannelMonitor<Signer> where Signer: Clone {
+       fn clone(&self) -> Self {
+               let inner = self.inner.lock().unwrap().clone();
+               ChannelMonitor::from_impl(inner)
+       }
 }
 
-pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
+#[derive(Clone, PartialEq)]
+pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
        latest_update_id: u64,
        commitment_transaction_number_obscure_factor: u64,
 
@@ -753,6 +792,8 @@ pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        /// Serialized to disk but should generally not be sent to Watchtowers.
        counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
 
+       counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
+
        // We store two holder commitment transactions to avoid any race conditions where we may update
        // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
        // various monitors for one channel being out of sync, and us broadcasting a holder
@@ -784,7 +825,8 @@ pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        // we further MUST NOT generate events during block/transaction-disconnection.
        pending_monitor_events: Vec<MonitorEvent>,
 
-       pending_events: Vec<Event>,
+       pub(super) pending_events: Vec<Event>,
+       pub(super) is_processing_pending_events: bool,
 
        // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
        // which to take actions once they reach enough confirmations. Each entry includes the
@@ -848,71 +890,31 @@ pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        /// The node_id of our counterparty
        counterparty_node_id: Option<PublicKey>,
 
-       secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
+       /// Initial counterparty commmitment data needed to recreate the commitment tx
+       /// in the persistence pipeline for third-party watchtowers. This will only be present on
+       /// monitors created after 0.0.117.
+       ///
+       /// Ordering of tuple data: (their_per_commitment_point, feerate_per_kw, to_broadcaster_sats,
+       /// to_countersignatory_sats)
+       initial_counterparty_commitment_info: Option<(PublicKey, u32, u64, u64)>,
 }
 
 /// Transaction outputs to watch for on-chain spends.
 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
 
-#[cfg(any(test, fuzzing, feature = "_test_utils"))]
-/// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
-/// object
-impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
-       fn eq(&self, other: &Self) -> bool {
-               let inner = self.inner.lock().unwrap();
-               let other = other.inner.lock().unwrap();
-               inner.eq(&other)
-       }
-}
-
-#[cfg(any(test, fuzzing, feature = "_test_utils"))]
-/// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
-/// object
-impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
        fn eq(&self, other: &Self) -> bool {
-               if self.latest_update_id != other.latest_update_id ||
-                       self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
-                       self.destination_script != other.destination_script ||
-                       self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
-                       self.counterparty_payment_script != other.counterparty_payment_script ||
-                       self.channel_keys_id != other.channel_keys_id ||
-                       self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
-                       self.funding_info != other.funding_info ||
-                       self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
-                       self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
-                       self.counterparty_commitment_params != other.counterparty_commitment_params ||
-                       self.funding_redeemscript != other.funding_redeemscript ||
-                       self.channel_value_satoshis != other.channel_value_satoshis ||
-                       self.their_cur_per_commitment_points != other.their_cur_per_commitment_points ||
-                       self.on_holder_tx_csv != other.on_holder_tx_csv ||
-                       self.commitment_secrets != other.commitment_secrets ||
-                       self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
-                       self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
-                       self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
-                       self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
-                       self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
-                       self.current_holder_commitment_number != other.current_holder_commitment_number ||
-                       self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
-                       self.payment_preimages != other.payment_preimages ||
-                       self.pending_monitor_events != other.pending_monitor_events ||
-                       self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
-                       self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
-                       self.outputs_to_watch != other.outputs_to_watch ||
-                       self.lockdown_from_offchain != other.lockdown_from_offchain ||
-                       self.holder_tx_signed != other.holder_tx_signed ||
-                       self.funding_spend_seen != other.funding_spend_seen ||
-                       self.funding_spend_confirmed != other.funding_spend_confirmed ||
-                       self.confirmed_commitment_tx_counterparty_output != other.confirmed_commitment_tx_counterparty_output ||
-                       self.htlcs_resolved_on_chain != other.htlcs_resolved_on_chain
-               {
-                       false
-               } else {
-                       true
-               }
+               // We need some kind of total lockorder. Absent a better idea, we sort by position in
+               // memory and take locks in that order (assuming that we can't move within memory while a
+               // lock is held).
+               let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
+               let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
+               let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
+               a.eq(&b)
        }
 }
 
-impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
                self.inner.lock().unwrap().write(writer)
        }
@@ -922,7 +924,7 @@ impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
                write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 
@@ -1078,19 +1080,57 @@ impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
 
                write_tlv_fields!(writer, {
                        (1, self.funding_spend_confirmed, option),
-                       (3, self.htlcs_resolved_on_chain, vec_type),
-                       (5, self.pending_monitor_events, vec_type),
+                       (3, self.htlcs_resolved_on_chain, required_vec),
+                       (5, self.pending_monitor_events, required_vec),
                        (7, self.funding_spend_seen, required),
                        (9, self.counterparty_node_id, option),
                        (11, self.confirmed_commitment_tx_counterparty_output, option),
-                       (13, self.spendable_txids_confirmed, vec_type),
+                       (13, self.spendable_txids_confirmed, required_vec),
+                       (15, self.counterparty_fulfilled_htlcs, required),
+                       (17, self.initial_counterparty_commitment_info, option),
                });
 
                Ok(())
        }
 }
 
-impl<Signer: Sign> ChannelMonitor<Signer> {
+macro_rules! _process_events_body {
+       ($self_opt: expr, $event_to_handle: expr, $handle_event: expr) => {
+               loop {
+                       let (pending_events, repeated_events);
+                       if let Some(us) = $self_opt {
+                               let mut inner = us.inner.lock().unwrap();
+                               if inner.is_processing_pending_events {
+                                       break;
+                               }
+                               inner.is_processing_pending_events = true;
+
+                               pending_events = inner.pending_events.clone();
+                               repeated_events = inner.get_repeated_events();
+                       } else { break; }
+                       let num_events = pending_events.len();
+
+                       for event in pending_events.into_iter().chain(repeated_events.into_iter()) {
+                               $event_to_handle = event;
+                               $handle_event;
+                       }
+
+                       if let Some(us) = $self_opt {
+                               let mut inner = us.inner.lock().unwrap();
+                               inner.pending_events.drain(..num_events);
+                               inner.is_processing_pending_events = false;
+                               if !inner.pending_events.is_empty() {
+                                       // If there's more events to process, go ahead and do so.
+                                       continue;
+                               }
+                       }
+                       break;
+               }
+       }
+}
+pub(super) use _process_events_body as process_events_body;
+
+impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
        /// For lockorder enforcement purposes, we need to have a single site which constructs the
        /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
        /// PartialEq implementation) we may decide a lockorder violation has occurred.
@@ -1140,7 +1180,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 
                let onchain_tx_handler =
                        OnchainTxHandler::new(destination_script.clone(), keys,
-                       channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
+                       channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
 
                let mut outputs_to_watch = HashMap::new();
                outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
@@ -1171,6 +1211,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                        counterparty_claimable_outpoints: HashMap::new(),
                        counterparty_commitment_txn_on_chain: HashMap::new(),
                        counterparty_hash_commitment_number: HashMap::new(),
+                       counterparty_fulfilled_htlcs: HashMap::new(),
 
                        prev_holder_signed_commitment_tx: None,
                        current_holder_commitment_tx: holder_commitment_tx,
@@ -1180,6 +1221,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                        payment_preimages: HashMap::new(),
                        pending_monitor_events: Vec::new(),
                        pending_events: Vec::new(),
+                       is_processing_pending_events: false,
 
                        onchain_events_awaiting_threshold_conf: Vec::new(),
                        outputs_to_watch,
@@ -1196,8 +1238,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 
                        best_block,
                        counterparty_node_id: Some(counterparty_node_id),
-
-                       secp_ctx,
+                       initial_counterparty_commitment_info: None,
                })
        }
 
@@ -1206,11 +1247,31 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                self.inner.lock().unwrap().provide_secret(idx, secret)
        }
 
+       /// A variant of `Self::provide_latest_counterparty_commitment_tx` used to provide
+       /// additional information to the monitor to store in order to recreate the initial
+       /// counterparty commitment transaction during persistence (mainly for use in third-party
+       /// watchtowers).
+       ///
+       /// This is used to provide the counterparty commitment information directly to the monitor
+       /// before the initial persistence of a new channel.
+       pub(crate) fn provide_initial_counterparty_commitment_tx<L: Deref>(
+               &self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
+               commitment_number: u64, their_cur_per_commitment_point: PublicKey, feerate_per_kw: u32,
+               to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, logger: &L,
+       )
+       where L::Target: Logger
+       {
+               self.inner.lock().unwrap().provide_initial_counterparty_commitment_tx(txid,
+                       htlc_outputs, commitment_number, their_cur_per_commitment_point, feerate_per_kw,
+                       to_broadcaster_value_sat, to_countersignatory_value_sat, logger);
+       }
+
        /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
        /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
        /// possibly future revocation/preimage information) to claim outputs where possible.
        /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
-       pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
+       #[cfg(test)]
+       fn provide_latest_counterparty_commitment_tx<L: Deref>(
                &self,
                txid: Txid,
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
@@ -1227,7 +1288,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                &self, holder_commitment_tx: HolderCommitmentTransaction,
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
        ) -> Result<(), ()> {
-               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs).map_err(|_| ())
+               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new(), Vec::new()).map_err(|_| ())
        }
 
        /// This is used to provide payment preimage(s) out-of-band during startup without updating the
@@ -1248,17 +1309,6 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                        payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
        }
 
-       pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
-               &self,
-               broadcaster: &B,
-               logger: &L,
-       ) where
-               B::Target: BroadcasterInterface,
-               L::Target: Logger,
-       {
-               self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
-       }
-
        /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
        /// itself.
        ///
@@ -1320,16 +1370,80 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
        }
 
-       /// Gets the list of pending events which were generated by previous actions, clearing the list
-       /// in the process.
+       /// Processes [`SpendableOutputs`] events produced from each [`ChannelMonitor`] upon maturity.
+       ///
+       /// For channels featuring anchor outputs, this method will also process [`BumpTransaction`]
+       /// events produced from each [`ChannelMonitor`] while there is a balance to claim onchain
+       /// within each channel. As the confirmation of a commitment transaction may be critical to the
+       /// safety of funds, we recommend invoking this every 30 seconds, or lower if running in an
+       /// environment with spotty connections, like on mobile.
        ///
-       /// This is called by the [`EventsProvider::process_pending_events`] implementation for
-       /// [`ChainMonitor`].
+       /// An [`EventHandler`] may safely call back to the provider, though this shouldn't be needed in
+       /// order to handle these events.
        ///
-       /// [`EventsProvider::process_pending_events`]: crate::util::events::EventsProvider::process_pending_events
-       /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
+       /// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
+       /// [`BumpTransaction`]: crate::events::Event::BumpTransaction
+       pub fn process_pending_events<H: Deref>(&self, handler: &H) where H::Target: EventHandler {
+               let mut ev;
+               process_events_body!(Some(self), ev, handler.handle_event(ev));
+       }
+
+       /// Processes any events asynchronously.
+       ///
+       /// See [`Self::process_pending_events`] for more information.
+       pub async fn process_pending_events_async<Future: core::future::Future, H: Fn(Event) -> Future>(
+               &self, handler: &H
+       ) {
+               let mut ev;
+               process_events_body!(Some(self), ev, { handler(ev).await });
+       }
+
+       #[cfg(test)]
        pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
-               self.inner.lock().unwrap().get_and_clear_pending_events()
+               let mut ret = Vec::new();
+               let mut lck = self.inner.lock().unwrap();
+               mem::swap(&mut ret, &mut lck.pending_events);
+               ret.append(&mut lck.get_repeated_events());
+               ret
+       }
+
+       /// Gets the counterparty's initial commitment transaction. The returned commitment
+       /// transaction is unsigned. This is intended to be called during the initial persistence of
+       /// the monitor (inside an implementation of [`Persist::persist_new_channel`]), to allow for
+       /// watchtowers in the persistence pipeline to have enough data to form justice transactions.
+       ///
+       /// This is similar to [`Self::counterparty_commitment_txs_from_update`], except
+       /// that for the initial commitment transaction, we don't have a corresponding update.
+       ///
+       /// This will only return `Some` for channel monitors that have been created after upgrading
+       /// to LDK 0.0.117+.
+       ///
+       /// [`Persist::persist_new_channel`]: crate::chain::chainmonitor::Persist::persist_new_channel
+       pub fn initial_counterparty_commitment_tx(&self) -> Option<CommitmentTransaction> {
+               self.inner.lock().unwrap().initial_counterparty_commitment_tx()
+       }
+
+       /// Gets all of the counterparty commitment transactions provided by the given update. This
+       /// may be empty if the update doesn't include any new counterparty commitments. Returned
+       /// commitment transactions are unsigned.
+       ///
+       /// This is provided so that watchtower clients in the persistence pipeline are able to build
+       /// justice transactions for each counterparty commitment upon each update. It's intended to be
+       /// used within an implementation of [`Persist::update_persisted_channel`], which is provided
+       /// with a monitor and an update.
+       ///
+       /// It is expected that a watchtower client may use this method to retrieve the latest counterparty
+       /// commitment transaction(s), and then hold the necessary data until a later update in which
+       /// the monitor has been updated with the corresponding revocation data, at which point the
+       /// monitor can sign the justice transaction.
+       ///
+       /// This will only return a non-empty list for monitor updates that have been created after
+       /// upgrading to LDK 0.0.117+. Note that no restriction lies on the monitors themselves, which
+       /// may have been created prior to upgrading.
+       ///
+       /// [`Persist::update_persisted_channel`]: crate::chain::chainmonitor::Persist::update_persisted_channel
+       pub fn counterparty_commitment_txs_from_update(&self, update: &ChannelMonitorUpdate) -> Vec<CommitmentTransaction> {
+               self.inner.lock().unwrap().counterparty_commitment_txs_from_update(update)
        }
 
        pub(crate) fn get_min_seen_secret(&self) -> u64 {
@@ -1519,9 +1633,30 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
        pub fn current_best_block(&self) -> BestBlock {
                self.inner.lock().unwrap().best_block.clone()
        }
+
+       /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
+       /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
+       /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
+       /// invoking this every 30 seconds, or lower if running in an environment with spotty
+       /// connections, like on mobile.
+       pub fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
+               &self, broadcaster: B, fee_estimator: F, logger: L,
+       )
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               let fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
+               let mut inner = self.inner.lock().unwrap();
+               let current_height = inner.best_block.height;
+               inner.onchain_tx_handler.rebroadcast_pending_claims(
+                       current_height, &broadcaster, &fee_estimator, &logger,
+               );
+       }
 }
 
-impl<Signer: Sign> ChannelMonitorImpl<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
        /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
        /// to one `Balance` for the HTLC.
        fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
@@ -1589,7 +1724,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        debug_assert!(htlc_input_idx_opt.is_some());
                                        BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
                                } else {
-                                       debug_assert!(!self.onchain_tx_handler.opt_anchors());
+                                       debug_assert!(!self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx());
                                        BitcoinOutPoint::new(*txid, 0)
                                }
                        } else {
@@ -1600,7 +1735,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                if let Some(conf_thresh) = holder_delayed_output_pending {
                        debug_assert!(holder_commitment);
                        return Some(Balance::ClaimableAwaitingConfirmations {
-                               claimable_amount_satoshis: htlc.amount_msat / 1000,
+                               amount_satoshis: htlc.amount_msat / 1000,
                                confirmation_height: conf_thresh,
                        });
                } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
@@ -1638,7 +1773,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
                                        "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
                                return Some(Balance::CounterpartyRevokedOutputClaimable {
-                                       claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                       amount_satoshis: htlc.amount_msat / 1000,
                                });
                        }
                } else if htlc.offered == holder_commitment {
@@ -1647,16 +1782,17 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        // and awaiting confirmations on it.
                        if let Some(conf_thresh) = holder_timeout_spend_pending {
                                return Some(Balance::ClaimableAwaitingConfirmations {
-                                       claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                       amount_satoshis: htlc.amount_msat / 1000,
                                        confirmation_height: conf_thresh,
                                });
                        } else {
                                return Some(Balance::MaybeTimeoutClaimableHTLC {
-                                       claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                       amount_satoshis: htlc.amount_msat / 1000,
                                        claimable_height: htlc.cltv_expiry,
+                                       payment_hash: htlc.payment_hash,
                                });
                        }
-               } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
+               } else if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
                        // Otherwise (the payment was inbound), only expose it as claimable if
                        // we know the preimage.
                        // Note that if there is a pending claim, but it did not use the
@@ -1665,26 +1801,29 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        debug_assert!(holder_timeout_spend_pending.is_none());
                        if let Some((conf_thresh, true)) = htlc_spend_pending {
                                return Some(Balance::ClaimableAwaitingConfirmations {
-                                       claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                       amount_satoshis: htlc.amount_msat / 1000,
                                        confirmation_height: conf_thresh,
                                });
                        } else {
                                return Some(Balance::ContentiousClaimable {
-                                       claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                       amount_satoshis: htlc.amount_msat / 1000,
                                        timeout_height: htlc.cltv_expiry,
+                                       payment_hash: htlc.payment_hash,
+                                       payment_preimage: *payment_preimage,
                                });
                        }
                } else if htlc_resolved.is_none() {
                        return Some(Balance::MaybePreimageClaimableHTLC {
-                               claimable_amount_satoshis: htlc.amount_msat / 1000,
+                               amount_satoshis: htlc.amount_msat / 1000,
                                expiry_height: htlc.cltv_expiry,
+                               payment_hash: htlc.payment_hash,
                        });
                }
                None
        }
 }
 
-impl<Signer: Sign> ChannelMonitor<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
        /// Gets the balances in this channel which are either claimable by us if we were to
        /// force-close the channel now or which are claimable on-chain (possibly awaiting
        /// confirmation).
@@ -1748,7 +1887,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                                } else { None }
                                        }) {
                                                res.push(Balance::ClaimableAwaitingConfirmations {
-                                                       claimable_amount_satoshis: value,
+                                                       amount_satoshis: value,
                                                        confirmation_height: conf_thresh,
                                                });
                                        } else {
@@ -1771,7 +1910,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                                        descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
                                                } = &event.event {
                                                        res.push(Balance::ClaimableAwaitingConfirmations {
-                                                               claimable_amount_satoshis: output.value,
+                                                               amount_satoshis: output.value,
                                                                confirmation_height: event.confirmation_threshold(),
                                                        });
                                                        if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
@@ -1790,7 +1929,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                                        .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
                                                if output_spendable {
                                                        res.push(Balance::CounterpartyRevokedOutputClaimable {
-                                                               claimable_amount_satoshis: amt,
+                                                               amount_satoshis: amt,
                                                        });
                                                }
                                        } else {
@@ -1803,7 +1942,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
                                if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
                                        res.push(Balance::ClaimableAwaitingConfirmations {
-                                               claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
+                                               amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
                                                confirmation_height: conf_thresh,
                                        });
                                }
@@ -1813,7 +1952,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                        walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
                                        if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
                                                res.push(Balance::ClaimableAwaitingConfirmations {
-                                                       claimable_amount_satoshis: prev_commitment.to_self_value_sat,
+                                                       amount_satoshis: prev_commitment.to_self_value_sat,
                                                        confirmation_height: conf_thresh,
                                                });
                                        }
@@ -1826,7 +1965,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                        // neither us nor our counterparty misbehaved. At worst we've under-estimated
                                        // the amount we can claim as we'll punish a misbehaving counterparty.
                                        res.push(Balance::ClaimableAwaitingConfirmations {
-                                               claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
+                                               amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
                                                confirmation_height: conf_thresh,
                                        });
                                }
@@ -1837,8 +1976,9 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                if htlc.transaction_output_index.is_none() { continue; }
                                if htlc.offered {
                                        res.push(Balance::MaybeTimeoutClaimableHTLC {
-                                               claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                               amount_satoshis: htlc.amount_msat / 1000,
                                                claimable_height: htlc.cltv_expiry,
+                                               payment_hash: htlc.payment_hash,
                                        });
                                } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
                                        claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
@@ -1846,13 +1986,14 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                        // As long as the HTLC is still in our latest commitment state, treat
                                        // it as potentially claimable, even if it has long-since expired.
                                        res.push(Balance::MaybePreimageClaimableHTLC {
-                                               claimable_amount_satoshis: htlc.amount_msat / 1000,
+                                               amount_satoshis: htlc.amount_msat / 1000,
                                                expiry_height: htlc.cltv_expiry,
+                                               payment_hash: htlc.payment_hash,
                                        });
                                }
                        }
                        res.push(Balance::ClaimableOnChannelClose {
-                               claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
+                               amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
                        });
                }
 
@@ -1863,9 +2004,10 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
        /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
        /// to the `ChannelManager` having been persisted.
        ///
-       /// This is similar to [`Self::get_pending_outbound_htlcs`] except it includes HTLCs which were
-       /// resolved by this `ChannelMonitor`.
-       pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
+       /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
+       /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
+       /// event from this `ChannelMonitor`).
+       pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
                let mut res = HashMap::new();
                // Just examine the available counterparty commitment transactions. See docs on
                // `fail_unbroadcast_htlcs`, below, for justification.
@@ -1875,7 +2017,8 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
                                        for &(ref htlc, ref source_option) in latest_outpoints.iter() {
                                                if let &Some(ref source) = source_option {
-                                                       res.insert((**source).clone(), htlc.clone());
+                                                       res.insert((**source).clone(), (htlc.clone(),
+                                                               us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
                                                }
                                        }
                                }
@@ -1890,9 +2033,14 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                res
        }
 
-       /// Gets the set of outbound HTLCs which are pending resolution in this channel.
+       /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
+       /// resolved with a preimage from our counterparty.
+       ///
        /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
-       pub(crate) fn get_pending_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
+       ///
+       /// Currently, the preimage is unused, however if it is present in the relevant internal state
+       /// an HTLC is always included even if it has been resolved.
+       pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
                let us = self.inner.lock().unwrap();
                // We're only concerned with the confirmation count of HTLC transactions, and don't
                // actually care how many confirmations a commitment transaction may or may not have. Thus,
@@ -1940,8 +2088,10 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                                                                Some(commitment_tx_output_idx) == htlc.transaction_output_index
                                                        } else { false }
                                                });
-                                               if !htlc_update_confd {
-                                                       res.insert(source.clone(), htlc.clone());
+                                               let counterparty_resolved_preimage_opt =
+                                                       us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
+                                               if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
+                                                       res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
                                                }
                                        }
                                }
@@ -2023,6 +2173,9 @@ macro_rules! fail_unbroadcast_htlcs {
                                                                }
                                                        }
                                                        if matched_htlc { continue; }
+                                                       if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
+                                                               continue;
+                                                       }
                                                        $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
                                                                if entry.height != $commitment_tx_conf_height { return true; }
                                                                match entry.event {
@@ -2045,7 +2198,7 @@ macro_rules! fail_unbroadcast_htlcs {
                                                                },
                                                        };
                                                        log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
-                                                               log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
+                                                               &htlc.payment_hash, $commitment_tx, $commitment_tx_type,
                                                                $commitment_txid_confirmed, entry.confirmation_threshold());
                                                        $self.onchain_events_awaiting_threshold_conf.push(entry);
                                                }
@@ -2082,7 +2235,7 @@ pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
        vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
 }
 
-impl<Signer: Sign> ChannelMonitorImpl<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
        /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
        /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
        /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
@@ -2094,8 +2247,23 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
                // events for now-revoked/fulfilled HTLCs.
                if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
-                       for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
-                               *source = None;
+                       if self.current_counterparty_commitment_txid.unwrap() != txid {
+                               let cur_claimables = self.counterparty_claimable_outpoints.get(
+                                       &self.current_counterparty_commitment_txid.unwrap()).unwrap();
+                               for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
+                                       if let Some(source) = source_opt {
+                                               if !cur_claimables.iter()
+                                                       .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
+                                               {
+                                                       self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
+                                               }
+                                       }
+                               }
+                               for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
+                                       *source_opt = None;
+                               }
+                       } else {
+                               assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
                        }
                }
 
@@ -2134,6 +2302,25 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                Ok(())
        }
 
+       pub(crate) fn provide_initial_counterparty_commitment_tx<L: Deref>(
+               &mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
+               commitment_number: u64, their_per_commitment_point: PublicKey, feerate_per_kw: u32,
+               to_broadcaster_value: u64, to_countersignatory_value: u64, logger: &L
+       )
+       where L::Target: Logger
+       {
+               self.initial_counterparty_commitment_info = Some((their_per_commitment_point.clone(),
+                       feerate_per_kw, to_broadcaster_value, to_countersignatory_value));
+
+               #[cfg(debug_assertions)] {
+                       let rebuilt_commitment_tx = self.initial_counterparty_commitment_tx().unwrap();
+                       debug_assert_eq!(rebuilt_commitment_tx.trust().txid(), txid);
+               }
+
+               self.provide_latest_counterparty_commitment_tx(txid, htlc_outputs, commitment_number,
+                               their_per_commitment_point, logger);
+       }
+
        pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_per_commitment_point: PublicKey, logger: &L) where L::Target: Logger {
                // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
                // so that a remote monitor doesn't learn anything unless there is a malicious close.
@@ -2180,28 +2367,83 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        /// is important that any clones of this channel monitor (including remote clones) by kept
        /// up-to-date as our holder commitment transaction is updated.
        /// Panics if set_on_holder_tx_csv has never been called.
-       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), &'static str> {
-               // block for Rust 1.34 compat
-               let mut new_holder_commitment_tx = {
-                       let trusted_tx = holder_commitment_tx.trust();
-                       let txid = trusted_tx.txid();
-                       let tx_keys = trusted_tx.keys();
-                       self.current_holder_commitment_number = trusted_tx.commitment_number();
-                       HolderSignedTx {
-                               txid,
-                               revocation_key: tx_keys.revocation_key,
-                               a_htlc_key: tx_keys.broadcaster_htlc_key,
-                               b_htlc_key: tx_keys.countersignatory_htlc_key,
-                               delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
-                               per_commitment_point: tx_keys.per_commitment_point,
-                               htlc_outputs,
-                               to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
-                               feerate_per_kw: trusted_tx.feerate_per_kw(),
+       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, mut htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)], nondust_htlc_sources: Vec<HTLCSource>) -> Result<(), &'static str> {
+               if htlc_outputs.iter().any(|(_, s, _)| s.is_some()) {
+                       // If we have non-dust HTLCs in htlc_outputs, ensure they match the HTLCs in the
+                       // `holder_commitment_tx`. In the future, we'll no longer provide the redundant data
+                       // and just pass in source data via `nondust_htlc_sources`.
+                       debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.trust().htlcs().len());
+                       for (a, b) in htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).map(|(h, _, _)| h).zip(holder_commitment_tx.trust().htlcs().iter()) {
+                               debug_assert_eq!(a, b);
                        }
+                       debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.counterparty_htlc_sigs.len());
+                       for (a, b) in htlc_outputs.iter().filter_map(|(_, s, _)| s.as_ref()).zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) {
+                               debug_assert_eq!(a, b);
+                       }
+                       debug_assert!(nondust_htlc_sources.is_empty());
+               } else {
+                       // If we don't have any non-dust HTLCs in htlc_outputs, assume they were all passed via
+                       // `nondust_htlc_sources`, building up the final htlc_outputs by combining
+                       // `nondust_htlc_sources` and the `holder_commitment_tx`
+                       #[cfg(debug_assertions)] {
+                               let mut prev = -1;
+                               for htlc in holder_commitment_tx.trust().htlcs().iter() {
+                                       assert!(htlc.transaction_output_index.unwrap() as i32 > prev);
+                                       prev = htlc.transaction_output_index.unwrap() as i32;
+                               }
+                       }
+                       debug_assert!(htlc_outputs.iter().all(|(htlc, _, _)| htlc.transaction_output_index.is_none()));
+                       debug_assert!(htlc_outputs.iter().all(|(_, sig_opt, _)| sig_opt.is_none()));
+                       debug_assert_eq!(holder_commitment_tx.trust().htlcs().len(), holder_commitment_tx.counterparty_htlc_sigs.len());
+
+                       let mut sources_iter = nondust_htlc_sources.into_iter();
+
+                       for (htlc, counterparty_sig) in holder_commitment_tx.trust().htlcs().iter()
+                               .zip(holder_commitment_tx.counterparty_htlc_sigs.iter())
+                       {
+                               if htlc.offered {
+                                       let source = sources_iter.next().expect("Non-dust HTLC sources didn't match commitment tx");
+                                       #[cfg(debug_assertions)] {
+                                               assert!(source.possibly_matches_output(htlc));
+                                       }
+                                       htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), Some(source)));
+                               } else {
+                                       htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), None));
+                               }
+                       }
+                       debug_assert!(sources_iter.next().is_none());
+               }
+
+               let trusted_tx = holder_commitment_tx.trust();
+               let txid = trusted_tx.txid();
+               let tx_keys = trusted_tx.keys();
+               self.current_holder_commitment_number = trusted_tx.commitment_number();
+               let mut new_holder_commitment_tx = HolderSignedTx {
+                       txid,
+                       revocation_key: tx_keys.revocation_key,
+                       a_htlc_key: tx_keys.broadcaster_htlc_key,
+                       b_htlc_key: tx_keys.countersignatory_htlc_key,
+                       delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
+                       per_commitment_point: tx_keys.per_commitment_point,
+                       htlc_outputs,
+                       to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
+                       feerate_per_kw: trusted_tx.feerate_per_kw(),
                };
                self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
                mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
                self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
+               for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
+                       #[cfg(debug_assertions)] {
+                               let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
+                                               &self.current_counterparty_commitment_txid.unwrap()).unwrap();
+                               assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
+                                       if let Some(source) = source_opt {
+                                               SentHTLCId::from_source(source) == *claimed_htlc_id
+                                       } else { false }
+                               }));
+                       }
+                       self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
+               }
                if self.holder_tx_signed {
                        return Err("Latest holder commitment signed has already been signed, update is rejected");
                }
@@ -2262,10 +2504,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                where B::Target: BroadcasterInterface,
                                        L::Target: Logger,
        {
-               for tx in self.get_latest_holder_commitment_txn(logger).iter() {
+               let commit_txs = self.get_latest_holder_commitment_txn(logger);
+               let mut txs = vec![];
+               for tx in commit_txs.iter() {
                        log_info!(logger, "Broadcasting local {}", log_tx!(tx));
-                       broadcaster.broadcast_transaction(tx);
+                       txs.push(tx);
                }
+               broadcaster.broadcast_transactions(&txs);
                self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
        }
 
@@ -2274,16 +2519,32 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                F::Target: FeeEstimator,
                L::Target: Logger,
        {
-               log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
-                       log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
-               // ChannelMonitor updates may be applied after force close if we receive a
-               // preimage for a broadcasted commitment transaction HTLC output that we'd
-               // like to claim on-chain. If this is the case, we no longer have guaranteed
-               // access to the monitor's update ID, so we use a sentinel value instead.
+               if self.latest_update_id == CLOSED_CHANNEL_UPDATE_ID && updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+                       log_info!(logger, "Applying post-force-closed update to monitor {} with {} change(s).",
+                               log_funding_info!(self), updates.updates.len());
+               } else if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+                       log_info!(logger, "Applying force close update to monitor {} with {} change(s).",
+                               log_funding_info!(self), updates.updates.len());
+               } else {
+                       log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} change(s).",
+                               log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
+               }
+               // ChannelMonitor updates may be applied after force close if we receive a preimage for a
+               // broadcasted commitment transaction HTLC output that we'd like to claim on-chain. If this
+               // is the case, we no longer have guaranteed access to the monitor's update ID, so we use a
+               // sentinel value instead.
+               //
+               // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still
+               // thinks the channel needs to have its commitment transaction broadcast, so we'll allow
+               // them as well.
                if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
                        assert_eq!(updates.updates.len(), 1);
                        match updates.updates[0] {
-                               ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
+                               ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
+                               // We should have already seen a `ChannelForceClosed` update if we're trying to
+                               // provide a preimage at this point.
+                               ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
+                                       debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
                                _ => {
                                        log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
                                        panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
@@ -2296,16 +2557,16 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
                for update in updates.updates.iter() {
                        match update {
-                               ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
+                               ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs, nondust_htlc_sources } => {
                                        log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
                                        if self.lockdown_from_offchain { panic!(); }
-                                       if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone()) {
+                                       if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs, nondust_htlc_sources.clone()) {
                                                log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
                                                log_error!(logger, "    {}", e);
                                                ret = Err(());
                                        }
                                }
-                               ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
+                               ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point, .. } => {
                                        log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
                                        self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
                                },
@@ -2325,20 +2586,32 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
                                        self.lockdown_from_offchain = true;
                                        if *should_broadcast {
+                                               // There's no need to broadcast our commitment transaction if we've seen one
+                                               // confirmed (even with 1 confirmation) as it'll be rejected as
+                                               // duplicate/conflicting.
+                                               let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
+                                                       self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
+                                                               OnchainEvent::FundingSpendConfirmation { .. } => true,
+                                                               _ => false,
+                                                       }).is_some();
+                                               if detected_funding_spend {
+                                                       log_trace!(logger, "Avoiding commitment broadcast, already detected confirmed spend onchain");
+                                                       continue;
+                                               }
                                                self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
                                                // If the channel supports anchor outputs, we'll need to emit an external
                                                // event to be consumed such that a child transaction is broadcast with a
                                                // high enough feerate for the parent commitment transaction to confirm.
-                                               if self.onchain_tx_handler.opt_anchors() {
+                                               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                                                        let funding_output = HolderFundingOutput::build(
                                                                self.funding_redeemscript.clone(), self.channel_value_satoshis,
-                                                               self.onchain_tx_handler.opt_anchors(),
+                                                               self.onchain_tx_handler.channel_type_features().clone(),
                                                        );
                                                        let best_block_height = self.best_block.height();
                                                        let commitment_package = PackageTemplate::build_package(
                                                                self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
                                                                PackageSolvingData::HolderFundingOutput(funding_output),
-                                                               best_block_height, false, best_block_height,
+                                                               best_block_height, best_block_height
                                                        );
                                                        self.onchain_tx_handler.update_claims_view_from_requests(
                                                                vec![commitment_package], best_block_height, best_block_height,
@@ -2364,9 +2637,22 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                },
                        }
                }
+
+               #[cfg(debug_assertions)] {
+                       self.counterparty_commitment_txs_from_update(updates);
+               }
+
+               // If the updates succeeded and we were in an already closed channel state, then there's no
+               // need to refuse any updates we expect to receive afer seeing a confirmed commitment.
+               if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id {
+                       return Ok(());
+               }
+
                self.latest_update_id = updates.update_id;
 
-               if ret.is_ok() && self.funding_spend_seen {
+               // Refuse updates after we've detected a spend onchain, but only if we haven't processed a
+               // force closed monitor update yet.
+               if ret.is_ok() && self.funding_spend_seen && self.latest_update_id != CLOSED_CHANNEL_UPDATE_ID {
                        log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
                        Err(())
                } else { ret }
@@ -2396,11 +2682,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                ret
        }
 
-       pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
-               let mut ret = Vec::new();
-               mem::swap(&mut ret, &mut self.pending_events);
-               #[cfg(anchors)]
-               for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
+       /// Gets the set of events that are repeated regularly (e.g. those which RBF bump
+       /// transactions). We're okay if we lose these on restart as they'll be regenerated for us at
+       /// some regular interval via [`ChannelMonitor::rebroadcast_pending_claims`].
+       pub(super) fn get_repeated_events(&mut self) -> Vec<Event> {
+               let pending_claim_events = self.onchain_tx_handler.get_and_clear_pending_claim_events();
+               let mut ret = Vec::with_capacity(pending_claim_events.len());
+               for (claim_id, claim_event) in pending_claim_events {
                        match claim_event {
                                ClaimEvent::BumpCommitment {
                                        package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
@@ -2411,12 +2699,16 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        let commitment_tx_fee_satoshis = self.channel_value_satoshis -
                                                commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
                                        ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
+                                               claim_id,
                                                package_target_feerate_sat_per_1000_weight,
                                                commitment_tx,
                                                commitment_tx_fee_satoshis,
                                                anchor_descriptor: AnchorDescriptor {
-                                                       channel_keys_id: self.channel_keys_id,
-                                                       channel_value_satoshis: self.channel_value_satoshis,
+                                                       channel_derivation_parameters: ChannelDerivationParameters {
+                                                               keys_id: self.channel_keys_id,
+                                                               value_satoshis: self.channel_value_satoshis,
+                                                               transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+                                                       },
                                                        outpoint: BitcoinOutPoint {
                                                                txid: commitment_txid,
                                                                vout: anchor_output_idx,
@@ -2425,11 +2717,99 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                pending_htlcs,
                                        }));
                                },
+                               ClaimEvent::BumpHTLC {
+                                       target_feerate_sat_per_1000_weight, htlcs, tx_lock_time,
+                               } => {
+                                       let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
+                                       for htlc in htlcs {
+                                               htlc_descriptors.push(HTLCDescriptor {
+                                                       channel_derivation_parameters: ChannelDerivationParameters {
+                                                               keys_id: self.channel_keys_id,
+                                                               value_satoshis: self.channel_value_satoshis,
+                                                               transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+                                                       },
+                                                       commitment_txid: htlc.commitment_txid,
+                                                       per_commitment_number: htlc.per_commitment_number,
+                                                       per_commitment_point: self.onchain_tx_handler.signer.get_per_commitment_point(
+                                                               htlc.per_commitment_number, &self.onchain_tx_handler.secp_ctx,
+                                                       ),
+                                                       htlc: htlc.htlc,
+                                                       preimage: htlc.preimage,
+                                                       counterparty_sig: htlc.counterparty_sig,
+                                               });
+                                       }
+                                       ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
+                                               claim_id,
+                                               target_feerate_sat_per_1000_weight,
+                                               htlc_descriptors,
+                                               tx_lock_time,
+                                       }));
+                               }
                        }
                }
                ret
        }
 
+       pub(crate) fn initial_counterparty_commitment_tx(&mut self) -> Option<CommitmentTransaction> {
+               let (their_per_commitment_point, feerate_per_kw, to_broadcaster_value,
+                       to_countersignatory_value) = self.initial_counterparty_commitment_info?;
+               let htlc_outputs = vec![];
+
+               let commitment_tx = self.build_counterparty_commitment_tx(INITIAL_COMMITMENT_NUMBER,
+                       &their_per_commitment_point, to_broadcaster_value, to_countersignatory_value,
+                       feerate_per_kw, htlc_outputs);
+               Some(commitment_tx)
+       }
+
+       fn build_counterparty_commitment_tx(
+               &self, commitment_number: u64, their_per_commitment_point: &PublicKey,
+               to_broadcaster_value: u64, to_countersignatory_value: u64, feerate_per_kw: u32,
+               mut nondust_htlcs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>
+       ) -> CommitmentTransaction {
+               let broadcaster_keys = &self.onchain_tx_handler.channel_transaction_parameters
+                       .counterparty_parameters.as_ref().unwrap().pubkeys;
+               let countersignatory_keys =
+                       &self.onchain_tx_handler.channel_transaction_parameters.holder_pubkeys;
+
+               let broadcaster_funding_key = broadcaster_keys.funding_pubkey;
+               let countersignatory_funding_key = countersignatory_keys.funding_pubkey;
+               let keys = TxCreationKeys::from_channel_static_keys(&their_per_commitment_point,
+                       &broadcaster_keys, &countersignatory_keys, &self.onchain_tx_handler.secp_ctx);
+               let channel_parameters =
+                       &self.onchain_tx_handler.channel_transaction_parameters.as_counterparty_broadcastable();
+
+               CommitmentTransaction::new_with_auxiliary_htlc_data(commitment_number,
+                       to_broadcaster_value, to_countersignatory_value, broadcaster_funding_key,
+                       countersignatory_funding_key, keys, feerate_per_kw, &mut nondust_htlcs,
+                       channel_parameters)
+       }
+
+       pub(crate) fn counterparty_commitment_txs_from_update(&self, update: &ChannelMonitorUpdate) -> Vec<CommitmentTransaction> {
+               update.updates.iter().filter_map(|update| {
+                       match update {
+                               &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid,
+                                       ref htlc_outputs, commitment_number, their_per_commitment_point,
+                                       feerate_per_kw: Some(feerate_per_kw),
+                                       to_broadcaster_value_sat: Some(to_broadcaster_value),
+                                       to_countersignatory_value_sat: Some(to_countersignatory_value) } => {
+
+                                       let nondust_htlcs = htlc_outputs.iter().filter_map(|(htlc, _)| {
+                                               htlc.transaction_output_index.map(|_| (htlc.clone(), None))
+                                       }).collect::<Vec<_>>();
+
+                                       let commitment_tx = self.build_counterparty_commitment_tx(commitment_number,
+                                                       &their_per_commitment_point, to_broadcaster_value,
+                                                       to_countersignatory_value, feerate_per_kw, nondust_htlcs);
+
+                                       debug_assert_eq!(commitment_tx.trust().txid(), commitment_txid);
+
+                                       Some(commitment_tx)
+                               },
+                               _ => None,
+                       }
+               }).collect()
+       }
+
        /// Can only fail if idx is < get_min_seen_secret
        fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
                self.commitment_secrets.get_secret(idx)
@@ -2480,9 +2860,9 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                if commitment_number >= self.get_min_seen_secret() {
                        let secret = self.get_secret(commitment_number).unwrap();
                        let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
-                       let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
-                       let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
-                       let delayed_key = chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
+                       let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
+                       let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
+                       let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx, &PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
 
                        let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
                        let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
@@ -2490,8 +2870,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        // First, process non-htlc outputs (to_holder & to_counterparty)
                        for (idx, outp) in tx.output.iter().enumerate() {
                                if outp.script_pubkey == revokeable_p2wsh {
-                                       let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv);
-                                       let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
+                                       let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv, self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx());
+                                       let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height);
                                        claimable_outpoints.push(justice_package);
                                        to_counterparty_output_info =
                                                Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
@@ -2508,8 +2888,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        return (claimable_outpoints, (commitment_txid, watch_outputs),
                                                                to_counterparty_output_info);
                                                }
-                                               let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_some());
-                                               let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
+                                               let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), &self.onchain_tx_handler.channel_transaction_parameters.channel_type_features);
+                                               let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, height);
                                                claimable_outpoints.push(justice_package);
                                        }
                                }
@@ -2595,8 +2975,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
 
                if let Some(transaction) = tx {
                        let revocation_pubkey = chan_utils::derive_public_revocation_key(
-                               &self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
-                       let delayed_key = chan_utils::derive_public_key(&self.secp_ctx,
+                               &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
+                       let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
                                &per_commitment_point,
                                &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
                        let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
@@ -2626,16 +3006,15 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
                                                                self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                                                self.counterparty_commitment_params.counterparty_htlc_base_key,
-                                                               preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
+                                                               preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
                                        } else {
                                                PackageSolvingData::CounterpartyReceivedHTLCOutput(
                                                        CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
                                                                self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                                                self.counterparty_commitment_params.counterparty_htlc_base_key,
-                                                               htlc.clone(), self.onchain_tx_handler.opt_anchors()))
+                                                               htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
                                        };
-                                       let aggregation = if !htlc.offered { false } else { true };
-                                       let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
+                                       let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry, 0);
                                        claimable_outpoints.push(counterparty_package);
                                }
                        }
@@ -2653,7 +3032,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        Ok(key) => key,
                        Err(_) => return (Vec::new(), None)
                };
-               let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
+               let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
 
                let htlc_txid = tx.txid();
                let mut claimable_outpoints = vec![];
@@ -2674,11 +3053,12 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                let revk_outp = RevokedOutput::build(
                                        per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                        self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
-                                       tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
+                                       tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv,
+                                       false
                                );
                                let justice_package = PackageTemplate::build_package(
                                        htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
-                                       height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
+                                       height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height
                                );
                                claimable_outpoints.push(justice_package);
                                if outputs_to_watch.is_none() {
@@ -2702,17 +3082,27 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
                        if let Some(transaction_output_index) = htlc.transaction_output_index {
                                let htlc_output = if htlc.offered {
-                                               HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
+                                       let htlc_output = HolderHTLCOutput::build_offered(
+                                               htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.channel_type_features().clone()
+                                       );
+                                       htlc_output
+                               } else {
+                                       let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
+                                               preimage.clone()
                                        } else {
-                                               let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
-                                                       preimage.clone()
-                                               } else {
-                                                       // We can't build an HTLC-Success transaction without the preimage
-                                                       continue;
-                                               };
-                                               HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
+                                               // We can't build an HTLC-Success transaction without the preimage
+                                               continue;
                                        };
-                               let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
+                                       let htlc_output = HolderHTLCOutput::build_accepted(
+                                               payment_preimage, htlc.amount_msat, self.onchain_tx_handler.channel_type_features().clone()
+                                       );
+                                       htlc_output
+                               };
+                               let htlc_package = PackageTemplate::build_package(
+                                       holder_tx.txid, transaction_output_index,
+                                       PackageSolvingData::HolderHTLCOutput(htlc_output),
+                                       htlc.cltv_expiry, conf_height
+                               );
                                claim_requests.push(htlc_package);
                        }
                }
@@ -2788,7 +3178,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                let mut holder_transactions = vec![commitment_tx];
                // When anchor outputs are present, the HTLC transactions are only valid once the commitment
                // transaction confirms.
-               if self.onchain_tx_handler.opt_anchors() {
+               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                        return holder_transactions;
                }
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
@@ -2826,7 +3216,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                let mut holder_transactions = vec![commitment_tx];
                // When anchor outputs are present, the HTLC transactions are only final once the commitment
                // transaction confirms due to the CSV 1 encumberance.
-               if self.onchain_tx_handler.opt_anchors() {
+               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                        return holder_transactions;
                }
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
@@ -3001,10 +3391,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                if let Some(new_outputs) = new_outputs_option {
                                                        watch_outputs.push(new_outputs);
                                                }
-                                               // Since there may be multiple HTLCs (all from the same commitment) being
-                                               // claimed by the counterparty within the same transaction, and
-                                               // `check_spend_counterparty_htlc` already checks for all of them, we can
-                                               // safely break from our loop.
+                                               // Since there may be multiple HTLCs for this channel (all spending the
+                                               // same commitment tx) being claimed by the counterparty within the same
+                                               // transaction, and `check_spend_counterparty_htlc` already checks all the
+                                               // ones relevant to this channel, we can safely break from our loop.
                                                break;
                                        }
                                }
@@ -3050,8 +3440,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
 
                let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
                if should_broadcast {
-                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
-                       let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), false, self.best_block.height());
+                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.channel_type_features().clone());
+                       let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), self.best_block.height());
                        claimable_outpoints.push(commitment_package);
                        self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
                        let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
@@ -3059,7 +3449,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        // We can't broadcast our HTLC transactions while the commitment transaction is
                        // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
                        // `transactions_confirmed`.
-                       if !self.onchain_tx_handler.opt_anchors() {
+                       if !self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                                // Because we're broadcasting a commitment transaction, we should construct the package
                                // assuming it gets confirmed in the next block. Sadly, we have code which considers
                                // "not yet confirmed" things as discardable, so we cannot do that here.
@@ -3117,7 +3507,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        }
 
                                        log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
-                                               log_bytes!(payment_hash.0), entry.txid);
+                                               &payment_hash, entry.txid);
                                        self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
                                                payment_hash,
                                                payment_preimage: None,
@@ -3134,7 +3524,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                OnchainEvent::MaturingOutput { descriptor } => {
                                        log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
                                        self.pending_events.push(Event::SpendableOutputs {
-                                               outputs: vec![descriptor]
+                                               outputs: vec![descriptor],
+                                               channel_id: Some(self.funding_info.0.to_channel_id()),
                                        });
                                        self.spendable_txids_confirmed.push(entry.txid);
                                },
@@ -3393,12 +3784,12 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
                                                log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
                                                        $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
-                                                       if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
+                                                       if outbound_htlc { "outbound" } else { "inbound" }, &$htlc.payment_hash,
                                                        if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back. We can likely claim the HTLC output with a revocation claim" });
                                        } else {
                                                log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
                                                        $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
-                                                       if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
+                                                       if outbound_htlc { "outbound" } else { "inbound" }, &$htlc.payment_hash,
                                                        if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
                                        }
                                }
@@ -3545,7 +3936,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        commitment_tx_output_idx: Some(input.previous_output.vout),
                                                },
                                        };
-                                       log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
+                                       log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", &payment_hash, entry.confirmation_threshold());
                                        self.onchain_events_awaiting_threshold_conf.push(entry);
                                }
                        }
@@ -3622,7 +4013,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        }
 }
 
-impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
+impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
 where
        T::Target: BroadcasterInterface,
        F::Target: FeeEstimator,
@@ -3637,8 +4028,9 @@ where
        }
 }
 
-impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
+impl<Signer: WriteableEcdsaChannelSigner, M, T: Deref, F: Deref, L: Deref> chain::Confirm for (M, T, F, L)
 where
+       M: Deref<Target = ChannelMonitor<Signer>>,
        T::Target: BroadcasterInterface,
        F::Target: FeeEstimator,
        L::Target: Logger,
@@ -3662,9 +4054,9 @@ where
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
 
-impl<'a, K: KeysInterface> ReadableArgs<&'a K>
-               for (BlockHash, ChannelMonitor<K::Signer>) {
-       fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
+impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
+               for (BlockHash, ChannelMonitor<SP::Signer>) {
+       fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
                macro_rules! unwrap_obj {
                        ($key: expr) => {
                                match $key {
@@ -3674,6 +4066,8 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
                        }
                }
 
+               let (entropy_source, signer_provider) = args;
+
                let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
                let latest_update_id: u64 = Readable::read(reader)?;
@@ -3847,8 +4241,8 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
                                return Err(DecodeError::InvalidValue);
                        }
                }
-               let onchain_tx_handler: OnchainTxHandler<K::Signer> = ReadableArgs::read(
-                       reader, (keys_manager, channel_value_satoshis, channel_keys_id)
+               let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
+                       reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
                )?;
 
                let lockdown_from_offchain = Readable::read(reader)?;
@@ -3877,19 +4271,20 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
                let mut counterparty_node_id = None;
                let mut confirmed_commitment_tx_counterparty_output = None;
                let mut spendable_txids_confirmed = Some(Vec::new());
+               let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
+               let mut initial_counterparty_commitment_info = None;
                read_tlv_fields!(reader, {
                        (1, funding_spend_confirmed, option),
-                       (3, htlcs_resolved_on_chain, vec_type),
-                       (5, pending_monitor_events, vec_type),
+                       (3, htlcs_resolved_on_chain, optional_vec),
+                       (5, pending_monitor_events, optional_vec),
                        (7, funding_spend_seen, option),
                        (9, counterparty_node_id, option),
                        (11, confirmed_commitment_tx_counterparty_output, option),
-                       (13, spendable_txids_confirmed, vec_type),
+                       (13, spendable_txids_confirmed, optional_vec),
+                       (15, counterparty_fulfilled_htlcs, option),
+                       (17, initial_counterparty_commitment_info, option),
                });
 
-               let mut secp_ctx = Secp256k1::new();
-               secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
-
                Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
                        latest_update_id,
                        commitment_transaction_number_obscure_factor,
@@ -3916,6 +4311,7 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
                        counterparty_claimable_outpoints,
                        counterparty_commitment_txn_on_chain,
                        counterparty_hash_commitment_number,
+                       counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
 
                        prev_holder_signed_commitment_tx,
                        current_holder_commitment_tx,
@@ -3925,6 +4321,7 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
                        payment_preimages,
                        pending_monitor_events: pending_monitor_events.unwrap(),
                        pending_events,
+                       is_processing_pending_events: false,
 
                        onchain_events_awaiting_threshold_conf,
                        outputs_to_watch,
@@ -3941,15 +4338,13 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K>
 
                        best_block,
                        counterparty_node_id,
-
-                       secp_ctx,
+                       initial_counterparty_commitment_info,
                })))
        }
 }
 
 #[cfg(test)]
 mod tests {
-       use bitcoin::blockdata::block::BlockHeader;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::opcodes;
        use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
@@ -3973,20 +4368,21 @@ mod tests {
        use crate::chain::channelmonitor::ChannelMonitor;
        use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
        use crate::chain::transaction::OutPoint;
-       use crate::chain::keysinterface::InMemorySigner;
+       use crate::sign::InMemorySigner;
+       use crate::events::ClosureReason;
        use crate::ln::{PaymentPreimage, PaymentHash};
        use crate::ln::chan_utils;
        use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
-       use crate::ln::channelmanager::{self, PaymentSendFailure, PaymentId};
+       use crate::ln::channelmanager::{PaymentSendFailure, PaymentId, RecipientOnionFields};
        use crate::ln::functional_test_utils::*;
        use crate::ln::script::ShutdownScript;
        use crate::util::errors::APIError;
-       use crate::util::events::{ClosureReason, MessageSendEventsProvider};
        use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
        use crate::util::ser::{ReadableArgs, Writeable};
        use crate::sync::{Arc, Mutex};
        use crate::io;
-       use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
+       use bitcoin::{PackedLockTime, Sequence, Witness};
+       use crate::ln::features::ChannelTypeFeatures;
        use crate::prelude::*;
 
        fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
@@ -4005,10 +4401,8 @@ mod tests {
                let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
                let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
                let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
-               let channel = create_announced_chan_between_nodes(
-                       &nodes, 0, 1, channelmanager::provided_init_features(), channelmanager::provided_init_features());
-               create_announced_chan_between_nodes(
-                       &nodes, 1, 2, channelmanager::provided_init_features(), channelmanager::provided_init_features());
+               let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
+               create_announced_chan_between_nodes(&nodes, 1, 2);
 
                // Rebalance somewhat
                send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
@@ -4027,27 +4421,26 @@ mod tests {
 
                // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
                // channel is now closed, but the ChannelManager doesn't know that yet.
-               let new_header = BlockHeader {
-                       version: 2, time: 0, bits: 0, nonce: 0,
-                       prev_blockhash: nodes[0].best_block_info().0,
-                       merkle_root: TxMerkleNode::all_zeros() };
+               let new_header = create_dummy_header(nodes[0].best_block_info().0, 0);
                let conf_height = nodes[0].best_block_info().1 + 1;
                nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
                        &[(0, broadcast_tx)], conf_height);
 
                let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
                                                &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
-                                               &nodes[1].keys_manager.backing).unwrap();
+                                               (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
 
                // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
                // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
                let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
-               unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
-                       true, APIError::ChannelUnavailable { ref err },
+               unwrap_send_err!(nodes[1].node.send_payment_with_route(&route, payment_hash,
+                               RecipientOnionFields::secret_only(payment_secret), PaymentId(payment_hash.0)
+                       ), true, APIError::ChannelUnavailable { ref err },
                        assert!(err.contains("ChannelMonitor storage failure")));
                check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
                check_closed_broadcast!(nodes[1], true);
-               check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
+               check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() }, 
+                       [nodes[0].node.get_our_node_id()], 100000);
 
                // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
                // and provides the claim preimages for the two pending HTLCs. The first update generates
@@ -4060,7 +4453,7 @@ mod tests {
                replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
                replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
 
-               let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
+               let broadcaster = TestBroadcaster::with_blocks(Arc::clone(&nodes[1].blocks));
                assert!(
                        pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
                        .is_err());
@@ -4086,11 +4479,10 @@ mod tests {
        fn test_prune_preimages() {
                let secp_ctx = Secp256k1::new();
                let logger = Arc::new(TestLogger::new());
-               let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
+               let broadcaster = Arc::new(TestBroadcaster::new(Network::Testnet));
                let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
 
                let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
-               let dummy_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
 
                let mut preimages = Vec::new();
                {
@@ -4101,7 +4493,7 @@ mod tests {
                        }
                }
 
-               macro_rules! preimages_slice_to_htlc_outputs {
+               macro_rules! preimages_slice_to_htlcs {
                        ($preimages_slice: expr) => {
                                {
                                        let mut res = Vec::new();
@@ -4112,21 +4504,20 @@ mod tests {
                                                        cltv_expiry: 0,
                                                        payment_hash: preimage.1.clone(),
                                                        transaction_output_index: Some(idx as u32),
-                                               }, None));
+                                               }, ()));
                                        }
                                        res
                                }
                        }
                }
-               macro_rules! preimages_to_holder_htlcs {
+               macro_rules! preimages_slice_to_htlc_outputs {
                        ($preimages_slice: expr) => {
-                               {
-                                       let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
-                                       let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
-                                       res
-                               }
+                               preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect()
                        }
                }
+               let dummy_sig = crate::util::crypto::sign(&secp_ctx,
+                       &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(),
+                       &SecretKey::from_slice(&[42; 32]).unwrap());
 
                macro_rules! test_preimages_exist {
                        ($preimages_slice: expr, $monitor: expr) => {
@@ -4143,10 +4534,10 @@ mod tests {
                        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,
                        [0; 32],
+                       [0; 32],
                );
 
                let counterparty_pubkeys = ChannelPublicKeys {
@@ -4166,26 +4557,26 @@ mod tests {
                                selected_contest_delay: 67,
                        }),
                        funding_outpoint: Some(funding_outpoint),
-                       opt_anchors: None,
-                       opt_non_zero_fee_anchors: None,
+                       channel_type_features: ChannelTypeFeatures::only_static_remote_key()
                };
                // Prune with one old state and a holder commitment tx holding a few overlaps with the
                // old state.
                let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
-               let best_block = BestBlock::from_genesis(Network::Testnet);
+               let best_block = BestBlock::from_network(Network::Testnet);
                let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
-                                                 Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
-                                                 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
-                                                 &channel_parameters,
-                                                 Script::new(), 46, 0,
-                                                 HolderCommitmentTransaction::dummy(), best_block, dummy_key);
-
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
-               let dummy_txid = dummy_tx.txid();
-               monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
-               monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
-               monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
-               monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
+                       Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
+                       (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
+                       &channel_parameters, Script::new(), 46, 0, HolderCommitmentTransaction::dummy(&mut Vec::new()),
+                       best_block, dummy_key);
+
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..10]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
+               monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
+                       preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
+               monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
+                       preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
                for &(ref preimage, ref hash) in preimages.iter() {
                        let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
                        monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
@@ -4199,6 +4590,9 @@ mod tests {
                test_preimages_exist!(&preimages[0..10], monitor);
                test_preimages_exist!(&preimages[15..20], monitor);
 
+               monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
+                       preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
+
                // Now provide a further secret, pruning preimages 15-17
                secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                monitor.provide_secret(281474976710654, secret.clone()).unwrap();
@@ -4206,9 +4600,15 @@ mod tests {
                test_preimages_exist!(&preimages[0..10], monitor);
                test_preimages_exist!(&preimages[17..20], monitor);
 
+               monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
+                       preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
+
                // Now update holder commitment tx info, pruning only element 18 as we still care about the
                // previous commitment tx's preimages too
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..5]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                monitor.provide_secret(281474976710653, secret.clone()).unwrap();
                assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
@@ -4216,7 +4616,10 @@ mod tests {
                test_preimages_exist!(&preimages[18..20], monitor);
 
                // But if we do it again, we'll prune 5-10
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..3]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx,
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                monitor.provide_secret(281474976710652, secret.clone()).unwrap();
                assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
@@ -4270,7 +4673,7 @@ mod tests {
                let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
 
                // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        for i in 0..4 {
@@ -4289,12 +4692,12 @@ mod tests {
                                value: 0,
                        });
                        let base_weight = claim_tx.weight();
-                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(opt_anchors), weight_revoked_offered_htlc(opt_anchors), weight_revoked_received_htlc(opt_anchors)];
+                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(channel_type_features), weight_revoked_offered_htlc(channel_type_features), weight_revoked_received_htlc(channel_type_features)];
                        let mut inputs_total_weight = 2; // count segwit flags
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }
@@ -4302,7 +4705,7 @@ mod tests {
                }
 
                // Claim tx with 1 offered HTLCs, 3 received HTLCs
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        for i in 0..4 {
@@ -4321,12 +4724,12 @@ mod tests {
                                value: 0,
                        });
                        let base_weight = claim_tx.weight();
-                       let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
+                       let inputs_weight = vec![weight_offered_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features)];
                        let mut inputs_total_weight = 2; // count segwit flags
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }
@@ -4334,7 +4737,7 @@ mod tests {
                }
 
                // Justice tx with 1 revoked HTLC-Success tx output
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        claim_tx.input.push(TxIn {
@@ -4356,7 +4759,7 @@ mod tests {
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }