X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannel.rs;h=c86136d6070a8f2c7909f8f3b39c743689ecd1f9;hb=8ee626c9a4b8b3477acb772ae5de0e49704183e6;hp=f1330fb92029e22b9be5e53a99f29c2c9725df2f;hpb=3b76c77d8c21aeb9f7303c1f2576d48a16da7f51;p=rust-lightning

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index f1330fb9..c86136d6 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -4,7 +4,7 @@ use bitcoin::blockdata::transaction::{TxIn, TxOut, Transaction, SigHashType};
 use bitcoin::blockdata::opcodes;
 use bitcoin::util::hash::BitcoinHash;
 use bitcoin::util::bip143;
-use bitcoin::consensus::encode::{self, Encodable, Decodable};
+use bitcoin::consensus::encode;
 
 use bitcoin_hashes::{Hash, HashEngine};
 use bitcoin_hashes::sha256::Hash as Sha256;
@@ -15,17 +15,18 @@ use secp256k1::key::{PublicKey,SecretKey};
 use secp256k1::{Secp256k1,Signature};
 use secp256k1;
 
+use ln::features::{ChannelFeatures, InitFeatures};
 use ln::msgs;
-use ln::msgs::{DecodeError, OptionalField, LocalFeatures, DataLossProtect};
+use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
 use ln::channelmonitor::ChannelMonitor;
 use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingForwardHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
-use ln::chan_utils::{TxCreationKeys,HTLCOutputInCommitment,HTLC_SUCCESS_TX_WEIGHT,HTLC_TIMEOUT_TX_WEIGHT};
+use ln::chan_utils::{LocalCommitmentTransaction, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys};
 use ln::chan_utils;
 use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
 use chain::transaction::OutPoint;
 use chain::keysinterface::{ChannelKeys, KeysInterface};
 use util::transaction_utils;
-use util::ser::{Readable, ReadableArgs, Writeable, Writer, WriterWriteAdaptor};
+use util::ser::{Readable, ReadableArgs, Writeable, Writer};
 use util::logger::{Logger, LogHolder};
 use util::errors::APIError;
 use util::config::{UserConfig,ChannelConfig};
@@ -297,12 +298,6 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
 	/// Max to_local and to_remote outputs in a remote-generated commitment transaction
 	max_commitment_tx_output_remote: ::std::sync::Mutex<(u64, u64)>,
 
-	#[cfg(test)]
-	// Used in ChannelManager's tests to send a revoked transaction
-	pub last_local_commitment_txn: Vec<Transaction>,
-	#[cfg(not(test))]
-	last_local_commitment_txn: Vec<Transaction>,
-
 	last_sent_closing_fee: Option<(u64, u64, Signature)>, // (feerate, fee, our_sig)
 
 	/// The hash of the block in which the funding transaction reached our CONF_TARGET. We use this
@@ -340,11 +335,8 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
 	//implied by OUR_MAX_HTLCS: our_max_accepted_htlcs: u16,
 	minimum_depth: u32,
 
-	their_funding_pubkey: Option<PublicKey>,
-	their_revocation_basepoint: Option<PublicKey>,
-	their_payment_basepoint: Option<PublicKey>,
-	their_delayed_payment_basepoint: Option<PublicKey>,
-	their_htlc_basepoint: Option<PublicKey>,
+	their_pubkeys: Option<ChannelPublicKeys>,
+
 	their_cur_commitment_point: Option<PublicKey>,
 
 	their_prev_commitment_point: Option<PublicKey>,
@@ -352,7 +344,7 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
 
 	their_shutdown_scriptpubkey: Option<Script>,
 
-	channel_monitor: ChannelMonitor,
+	channel_monitor: ChannelMonitor<ChanSigner>,
 
 	network_sync: UpdateStatus,
 
@@ -373,25 +365,19 @@ const B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT: u64 = 104; // prevout: 40, nSequence:
 /// it's 2^24.
 pub const MAX_FUNDING_SATOSHIS: u64 = (1 << 24);
 
-#[cfg(test)]
-pub const ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 138; //Here we have a diff due to HTLC CLTV expiry being < 2^15 in test
-#[cfg(not(test))]
-pub const ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 139;
-pub const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
-
 /// Used to return a simple Error back to ChannelManager. Will get converted to a
 /// msgs::ErrorAction::SendErrorMessage or msgs::ErrorAction::IgnoreError as appropriate with our
 /// channel_id in ChannelManager.
-pub(super) enum ChannelError {
+pub(super) enum ChannelError<ChanSigner: ChannelKeys> {
 	Ignore(&'static str),
 	Close(&'static str),
 	CloseDelayBroadcast {
 		msg: &'static str,
-		update: Option<ChannelMonitor>
+		update: Option<ChannelMonitor<ChanSigner>>,
 	},
 }
 
-impl fmt::Debug for ChannelError {
+impl<ChanSigner: ChannelKeys> fmt::Debug for ChannelError<ChanSigner> {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		match self {
 			&ChannelError::Ignore(e) => write!(f, "Ignore : {}", e),
@@ -434,7 +420,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	// Constructors:
 	pub fn new_outbound(fee_estimator: &FeeEstimator, keys_provider: &Arc<KeysInterface<ChanKeySigner = ChanSigner>>, their_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, logger: Arc<Logger>, config: &UserConfig) -> Result<Channel<ChanSigner>, APIError> {
-		let chan_keys = keys_provider.get_channel_keys(false);
+		let chan_keys = keys_provider.get_channel_keys(false, channel_value_satoshis);
 
 		if channel_value_satoshis >= MAX_FUNDING_SATOSHIS {
 			return Err(APIError::APIMisuseError{err: "funding value > 2^24"});
@@ -456,7 +442,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 
 		let secp_ctx = Secp256k1::new();
-		let channel_monitor = ChannelMonitor::new(chan_keys.revocation_base_key(), chan_keys.delayed_payment_base_key(),
+		let channel_monitor = ChannelMonitor::new(chan_keys.clone(),
+		                                          chan_keys.funding_key(), chan_keys.revocation_base_key(), chan_keys.delayed_payment_base_key(),
 		                                          chan_keys.htlc_base_key(), chan_keys.payment_base_key(), &keys_provider.get_shutdown_pubkey(), config.own_channel_config.our_to_self_delay,
 		                                          keys_provider.get_destination_script(), logger.clone());
 
@@ -498,8 +485,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			#[cfg(debug_assertions)]
 			max_commitment_tx_output_remote: ::std::sync::Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
 
-			last_local_commitment_txn: Vec::new(),
-
 			last_sent_closing_fee: None,
 
 			funding_tx_confirmed_in: None,
@@ -519,11 +504,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			their_max_accepted_htlcs: 0,
 			minimum_depth: 0, // Filled in in accept_channel
 
-			their_funding_pubkey: None,
-			their_revocation_basepoint: None,
-			their_payment_basepoint: None,
-			their_delayed_payment_basepoint: None,
-			their_htlc_basepoint: None,
+			their_pubkeys: None,
 			their_cur_commitment_point: None,
 
 			their_prev_commitment_point: None,
@@ -539,7 +520,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		})
 	}
 
-	fn check_remote_fee(fee_estimator: &FeeEstimator, feerate_per_kw: u32) -> Result<(), ChannelError> {
+	fn check_remote_fee(fee_estimator: &FeeEstimator, feerate_per_kw: u32) -> Result<(), ChannelError<ChanSigner>> {
 		if (feerate_per_kw as u64) < fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background) {
 			return Err(ChannelError::Close("Peer's feerate much too low"));
 		}
@@ -551,8 +532,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// Creates a new channel from a remote sides' request for one.
 	/// Assumes chain_hash has already been checked and corresponds with what we expect!
-	pub fn new_from_req(fee_estimator: &FeeEstimator, keys_provider: &Arc<KeysInterface<ChanKeySigner = ChanSigner>>, their_node_id: PublicKey, their_local_features: LocalFeatures, msg: &msgs::OpenChannel, user_id: u64, logger: Arc<Logger>, config: &UserConfig) -> Result<Channel<ChanSigner>, ChannelError> {
-		let chan_keys = keys_provider.get_channel_keys(true);
+	pub fn new_from_req(fee_estimator: &FeeEstimator, keys_provider: &Arc<KeysInterface<ChanKeySigner = ChanSigner>>, their_node_id: PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel, user_id: u64, logger: Arc<Logger>, config: &UserConfig) -> Result<Channel<ChanSigner>, ChannelError<ChanSigner>> {
+		let mut chan_keys = keys_provider.get_channel_keys(true, msg.funding_satoshis);
+		let their_pubkeys = ChannelPublicKeys {
+			funding_pubkey: msg.funding_pubkey,
+			revocation_basepoint: msg.revocation_basepoint,
+			payment_basepoint: msg.payment_basepoint,
+			delayed_payment_basepoint: msg.delayed_payment_basepoint,
+			htlc_basepoint: msg.htlc_basepoint
+		};
+		chan_keys.set_remote_channel_pubkeys(&their_pubkeys);
 		let mut local_config = (*config).channel_options.clone();
 
 		if config.own_channel_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
@@ -652,13 +641,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		let secp_ctx = Secp256k1::new();
-		let mut channel_monitor = ChannelMonitor::new(chan_keys.revocation_base_key(), chan_keys.delayed_payment_base_key(),
-		                                              chan_keys.htlc_base_key(), chan_keys.payment_base_key(), &keys_provider.get_shutdown_pubkey(), config.own_channel_config.our_to_self_delay,
-		                                              keys_provider.get_destination_script(), logger.clone());
-		channel_monitor.set_their_base_keys(&msg.htlc_basepoint, &msg.delayed_payment_basepoint);
-		channel_monitor.set_their_to_self_delay(msg.to_self_delay);
+		let channel_monitor = ChannelMonitor::new(chan_keys.clone(),
+		                                          chan_keys.funding_key(), chan_keys.revocation_base_key(), chan_keys.delayed_payment_base_key(),
+		                                          chan_keys.htlc_base_key(), chan_keys.payment_base_key(), &keys_provider.get_shutdown_pubkey(), config.own_channel_config.our_to_self_delay,
+		                                          keys_provider.get_destination_script(), logger.clone());
 
-		let their_shutdown_scriptpubkey = if their_local_features.supports_upfront_shutdown_script() {
+		let their_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
 			match &msg.shutdown_scriptpubkey {
 				&OptionalField::Present(ref script) => {
 					// Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. We enforce it while receiving shutdown msg
@@ -716,8 +704,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			#[cfg(debug_assertions)]
 			max_commitment_tx_output_remote: ::std::sync::Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
 
-			last_local_commitment_txn: Vec::new(),
-
 			last_sent_closing_fee: None,
 
 			funding_tx_confirmed_in: None,
@@ -738,11 +724,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			their_max_accepted_htlcs: msg.max_accepted_htlcs,
 			minimum_depth: config.own_channel_config.minimum_depth,
 
-			their_funding_pubkey: Some(msg.funding_pubkey),
-			their_revocation_basepoint: Some(msg.revocation_basepoint),
-			their_payment_basepoint: Some(msg.payment_basepoint),
-			their_delayed_payment_basepoint: Some(msg.delayed_payment_basepoint),
-			their_htlc_basepoint: Some(msg.htlc_basepoint),
+			their_pubkeys: Some(their_pubkeys),
 			their_cur_commitment_point: Some(msg.first_per_commitment_point),
 
 			their_prev_commitment_point: None,
@@ -758,7 +740,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		};
 
 		let obscure_factor = chan.get_commitment_transaction_number_obscure_factor();
-		chan.channel_monitor.set_commitment_obscure_factor(obscure_factor);
+		let funding_redeemscript = chan.get_funding_redeemscript();
+		chan.channel_monitor.set_basic_channel_info(&msg.htlc_basepoint, &msg.delayed_payment_basepoint, msg.to_self_delay, funding_redeemscript, msg.funding_satoshis, obscure_factor);
 
 		Ok(chan)
 	}
@@ -776,11 +759,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		let mut sha = Sha256::engine();
 		let our_payment_basepoint = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.payment_base_key());
 
+		let their_payment_basepoint = &self.their_pubkeys.as_ref().unwrap().payment_basepoint.serialize();
 		if self.channel_outbound {
 			sha.input(&our_payment_basepoint.serialize());
-			sha.input(&self.their_payment_basepoint.unwrap().serialize());
+			sha.input(their_payment_basepoint);
 		} else {
-			sha.input(&self.their_payment_basepoint.unwrap().serialize());
+			sha.input(their_payment_basepoint);
 			sha.input(&our_payment_basepoint.serialize());
 		}
 		let res = Sha256::from_engine(sha).into_inner();
@@ -1095,74 +1079,36 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// our counterparty!)
 	/// The result is a transaction which we can revoke ownership of (ie a "local" transaction)
 	/// TODO Some magic rust shit to compile-time check this?
-	fn build_local_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError> {
+	fn build_local_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError<ChanSigner>> {
 		let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(commitment_number));
 		let delayed_payment_base = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.delayed_payment_base_key());
 		let htlc_basepoint = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.htlc_base_key());
+		let their_pubkeys = self.their_pubkeys.as_ref().unwrap();
 
-		Ok(secp_check!(TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, &delayed_payment_base, &htlc_basepoint, &self.their_revocation_basepoint.unwrap(), &self.their_payment_basepoint.unwrap(), &self.their_htlc_basepoint.unwrap()), "Local tx keys generation got bogus keys"))
+		Ok(secp_check!(TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, &delayed_payment_base, &htlc_basepoint, &their_pubkeys.revocation_basepoint, &their_pubkeys.payment_basepoint, &their_pubkeys.htlc_basepoint), "Local tx keys generation got bogus keys"))
 	}
 
 	#[inline]
 	/// Creates a set of keys for build_commitment_transaction to generate a transaction which we
 	/// will sign and send to our counterparty.
 	/// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
-	fn build_remote_transaction_keys(&self) -> Result<TxCreationKeys, ChannelError> {
+	fn build_remote_transaction_keys(&self) -> Result<TxCreationKeys, ChannelError<ChanSigner>> {
 		//TODO: Ensure that the payment_key derived here ends up in the library users' wallet as we
 		//may see payments to it!
 		let payment_basepoint = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.payment_base_key());
 		let revocation_basepoint = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.revocation_base_key());
 		let htlc_basepoint = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.htlc_base_key());
+		let their_pubkeys = self.their_pubkeys.as_ref().unwrap();
 
-		Ok(secp_check!(TxCreationKeys::new(&self.secp_ctx, &self.their_cur_commitment_point.unwrap(), &self.their_delayed_payment_basepoint.unwrap(), &self.their_htlc_basepoint.unwrap(), &revocation_basepoint, &payment_basepoint, &htlc_basepoint), "Remote tx keys generation got bogus keys"))
+		Ok(secp_check!(TxCreationKeys::new(&self.secp_ctx, &self.their_cur_commitment_point.unwrap(), &their_pubkeys.delayed_payment_basepoint, &their_pubkeys.htlc_basepoint, &revocation_basepoint, &payment_basepoint, &htlc_basepoint), "Remote tx keys generation got bogus keys"))
 	}
 
 	/// Gets the redeemscript for the funding transaction output (ie the funding transaction output
 	/// pays to get_funding_redeemscript().to_v0_p2wsh()).
 	/// Panics if called before accept_channel/new_from_req
 	pub fn get_funding_redeemscript(&self) -> Script {
-		let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
-		let our_funding_key = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()).serialize();
-		let their_funding_key = self.their_funding_pubkey.expect("get_funding_redeemscript only allowed after accept_channel").serialize();
-		if our_funding_key[..] < their_funding_key[..] {
-			builder.push_slice(&our_funding_key)
-				.push_slice(&their_funding_key)
-		} else {
-			builder.push_slice(&their_funding_key)
-				.push_slice(&our_funding_key)
-		}.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
-	}
-
-	fn sign_commitment_transaction(&self, tx: &mut Transaction, their_sig: &Signature) -> Signature {
-		if tx.input.len() != 1 {
-			panic!("Tried to sign commitment transaction that had input count != 1!");
-		}
-		if tx.input[0].witness.len() != 0 {
-			panic!("Tried to re-sign commitment transaction");
-		}
-
-		let funding_redeemscript = self.get_funding_redeemscript();
-
-		let sighash = hash_to_message!(&bip143::SighashComponents::new(&tx).sighash_all(&tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]);
-		let our_sig = self.secp_ctx.sign(&sighash, self.local_keys.funding_key());
-
-		tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
-
-		let our_funding_key = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()).serialize();
-		let their_funding_key = self.their_funding_pubkey.unwrap().serialize();
-		if our_funding_key[..] < their_funding_key[..] {
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
-		} else {
-			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
-		}
-		tx.input[0].witness[1].push(SigHashType::All as u8);
-		tx.input[0].witness[2].push(SigHashType::All as u8);
-
-		tx.input[0].witness.push(funding_redeemscript.into_bytes());
-
-		our_sig
+		let our_funding_key = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key());
+		make_funding_redeemscript(&our_funding_key, self.their_funding_pubkey())
 	}
 
 	/// Builds the htlc-success or htlc-timeout transaction which spends a given HTLC output
@@ -1172,58 +1118,10 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		chan_utils::build_htlc_transaction(prev_hash, feerate_per_kw, if local { self.their_to_self_delay } else { self.our_to_self_delay }, htlc, &keys.a_delayed_payment_key, &keys.revocation_key)
 	}
 
-	fn create_htlc_tx_signature(&self, tx: &Transaction, htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Result<(Script, Signature, bool), ChannelError> {
-		if tx.input.len() != 1 {
-			panic!("Tried to sign HTLC transaction that had input count != 1!");
-		}
-
-		let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
-
-		let our_htlc_key = secp_check!(chan_utils::derive_private_key(&self.secp_ctx, &keys.per_commitment_point, self.local_keys.htlc_base_key()), "Derived invalid key, peer is maliciously selecting parameters");
-		let sighash = hash_to_message!(&bip143::SighashComponents::new(&tx).sighash_all(&tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
-		let is_local_tx = PublicKey::from_secret_key(&self.secp_ctx, &our_htlc_key) == keys.a_htlc_key;
-		Ok((htlc_redeemscript, self.secp_ctx.sign(&sighash, &our_htlc_key), is_local_tx))
-	}
-
-	/// Signs a transaction created by build_htlc_transaction. If the transaction is an
-	/// HTLC-Success transaction (ie htlc.offered is false), preimage must be set!
-	fn sign_htlc_transaction(&self, tx: &mut Transaction, their_sig: &Signature, preimage: &Option<PaymentPreimage>, htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Result<Signature, ChannelError> {
-		if tx.input.len() != 1 {
-			panic!("Tried to sign HTLC transaction that had input count != 1!");
-		}
-		if tx.input[0].witness.len() != 0 {
-			panic!("Tried to re-sign HTLC transaction");
-		}
-
-		let (htlc_redeemscript, our_sig, local_tx) = self.create_htlc_tx_signature(tx, htlc, keys)?;
-
-		tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
-
-		if local_tx { // b, then a
-			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
-		} else {
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
-		}
-		tx.input[0].witness[1].push(SigHashType::All as u8);
-		tx.input[0].witness[2].push(SigHashType::All as u8);
-
-		if htlc.offered {
-			tx.input[0].witness.push(Vec::new());
-		} else {
-			tx.input[0].witness.push(preimage.unwrap().0.to_vec());
-		}
-
-		tx.input[0].witness.push(htlc_redeemscript.into_bytes());
-
-		Ok(our_sig)
-	}
-
 	/// Per HTLC, only one get_update_fail_htlc or get_update_fulfill_htlc call may be made.
 	/// In such cases we debug_assert!(false) and return an IgnoreError. Thus, will always return
 	/// Ok(_) if debug assertions are turned on and preconditions are met.
-	fn get_update_fulfill_htlc(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage) -> Result<(Option<msgs::UpdateFulfillHTLC>, Option<ChannelMonitor>), ChannelError> {
+	fn get_update_fulfill_htlc(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage) -> Result<(Option<msgs::UpdateFulfillHTLC>, Option<ChannelMonitor<ChanSigner>>), ChannelError<ChanSigner>> {
 		// Either ChannelFunded got set (which means it won't be unset) or there is no way any
 		// caller thought we could have something claimed (cause we wouldn't have accepted in an
 		// incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us,
@@ -1315,7 +1213,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}), Some(self.channel_monitor.clone())))
 	}
 
-	pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage) -> Result<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option<ChannelMonitor>), ChannelError> {
+	pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage) -> Result<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option<ChannelMonitor<ChanSigner>>), ChannelError<ChanSigner>> {
 		match self.get_update_fulfill_htlc(htlc_id, payment_preimage)? {
 			(Some(update_fulfill_htlc), _) => {
 				let (commitment, monitor_update) = self.send_commitment_no_status_check()?;
@@ -1329,7 +1227,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// Per HTLC, only one get_update_fail_htlc or get_update_fulfill_htlc call may be made.
 	/// In such cases we debug_assert!(false) and return an IgnoreError. Thus, will always return
 	/// Ok(_) if debug assertions are turned on and preconditions are met.
-	pub fn get_update_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket) -> Result<Option<msgs::UpdateFailHTLC>, ChannelError> {
+	pub fn get_update_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket) -> Result<Option<msgs::UpdateFailHTLC>, ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			panic!("Was asked to fail an HTLC when channel was not in an operational state");
 		}
@@ -1397,7 +1295,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	// Message handlers:
 
-	pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_local_features: LocalFeatures) -> Result<(), ChannelError> {
+	pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: InitFeatures) -> Result<(), ChannelError<ChanSigner>> {
 		// Check sanity of message fields:
 		if !self.channel_outbound {
 			return Err(ChannelError::Close("Got an accept_channel message from an inbound peer"));
@@ -1456,7 +1354,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("We consider the minimum depth to be unreasonably large"));
 		}
 
-		let their_shutdown_scriptpubkey = if their_local_features.supports_upfront_shutdown_script() {
+		let their_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
 			match &msg.shutdown_scriptpubkey {
 				&OptionalField::Present(ref script) => {
 					// Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. We enforce it while receiving shutdown msg
@@ -1477,8 +1375,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		} else { None };
 
-		self.channel_monitor.set_their_base_keys(&msg.htlc_basepoint, &msg.delayed_payment_basepoint);
-
 		self.their_dust_limit_satoshis = msg.dust_limit_satoshis;
 		self.their_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000);
 		self.their_channel_reserve_satoshis = msg.channel_reserve_satoshis;
@@ -1486,46 +1382,56 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		self.their_to_self_delay = msg.to_self_delay;
 		self.their_max_accepted_htlcs = msg.max_accepted_htlcs;
 		self.minimum_depth = msg.minimum_depth;
-		self.their_funding_pubkey = Some(msg.funding_pubkey);
-		self.their_revocation_basepoint = Some(msg.revocation_basepoint);
-		self.their_payment_basepoint = Some(msg.payment_basepoint);
-		self.their_delayed_payment_basepoint = Some(msg.delayed_payment_basepoint);
-		self.their_htlc_basepoint = Some(msg.htlc_basepoint);
+
+		let their_pubkeys = ChannelPublicKeys {
+			funding_pubkey: msg.funding_pubkey,
+			revocation_basepoint: msg.revocation_basepoint,
+			payment_basepoint: msg.payment_basepoint,
+			delayed_payment_basepoint: msg.delayed_payment_basepoint,
+			htlc_basepoint: msg.htlc_basepoint
+		};
+
+		self.local_keys.set_remote_channel_pubkeys(&their_pubkeys);
+		self.their_pubkeys = Some(their_pubkeys);
+
 		self.their_cur_commitment_point = Some(msg.first_per_commitment_point);
 		self.their_shutdown_scriptpubkey = their_shutdown_scriptpubkey;
 
 		let obscure_factor = self.get_commitment_transaction_number_obscure_factor();
-		self.channel_monitor.set_commitment_obscure_factor(obscure_factor);
-		self.channel_monitor.set_their_to_self_delay(msg.to_self_delay);
+		let funding_redeemscript = self.get_funding_redeemscript();
+		self.channel_monitor.set_basic_channel_info(&msg.htlc_basepoint, &msg.delayed_payment_basepoint, msg.to_self_delay, funding_redeemscript, self.channel_value_satoshis, obscure_factor);
 
 		self.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32;
 
 		Ok(())
 	}
 
-	fn funding_created_signature(&mut self, sig: &Signature) -> Result<(Transaction, Transaction, Signature, TxCreationKeys), ChannelError> {
+	fn funding_created_signature(&mut self, sig: &Signature) -> Result<(Transaction, LocalCommitmentTransaction, Signature, TxCreationKeys), ChannelError<ChanSigner>> {
 		let funding_script = self.get_funding_redeemscript();
 
 		let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?;
-		let mut local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
+		let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
 		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]);
 
 		// They sign the "local" commitment transaction...
-		secp_check!(self.secp_ctx.verify(&local_sighash, &sig, &self.their_funding_pubkey.unwrap()), "Invalid funding_created signature from peer");
+		secp_check!(self.secp_ctx.verify(&local_sighash, &sig, self.their_funding_pubkey()), "Invalid funding_created signature from peer");
 
-		// ...and we sign it, allowing us to broadcast the tx if we wish
-		self.sign_commitment_transaction(&mut local_initial_commitment_tx, sig);
+		let localtx = LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx, sig, &PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()), self.their_funding_pubkey());
 
 		let remote_keys = self.build_remote_transaction_keys()?;
 		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0;
-		let remote_signature = self.local_keys.sign_remote_commitment(self.channel_value_satoshis, &self.get_funding_redeemscript(), self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
+		let remote_signature = self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
 				.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0;
 
 		// We sign the "remote" commitment transaction, allowing them to broadcast the tx if they wish.
-		Ok((remote_initial_commitment_tx, local_initial_commitment_tx, remote_signature, local_keys))
+		Ok((remote_initial_commitment_tx, localtx, remote_signature, local_keys))
+	}
+
+	fn their_funding_pubkey(&self) -> &PublicKey {
+		&self.their_pubkeys.as_ref().expect("their_funding_pubkey() only allowed after accept_channel").funding_pubkey
 	}
 
-	pub fn funding_created(&mut self, msg: &msgs::FundingCreated) -> Result<(msgs::FundingSigned, ChannelMonitor), ChannelError> {
+	pub fn funding_created(&mut self, msg: &msgs::FundingCreated) -> Result<(msgs::FundingSigned, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		if self.channel_outbound {
 			return Err(ChannelError::Close("Received funding_created for an outbound channel?"));
 		}
@@ -1556,7 +1462,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		// Now that we're past error-generating stuff, update our local state:
 
 		self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap());
-		self.last_local_commitment_txn = vec![local_initial_commitment_tx.clone()];
 		self.channel_monitor.provide_latest_local_commitment_tx_info(local_initial_commitment_tx, local_keys, self.feerate_per_kw, Vec::new());
 		self.channel_state = ChannelState::FundingSent as u32;
 		self.channel_id = funding_txo.to_channel_id();
@@ -1571,7 +1476,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// Handles a funding_signed message from the remote end.
 	/// If this call is successful, broadcast the funding transaction (and not before!)
-	pub fn funding_signed(&mut self, msg: &msgs::FundingSigned) -> Result<ChannelMonitor, ChannelError> {
+	pub fn funding_signed(&mut self, msg: &msgs::FundingSigned) -> Result<ChannelMonitor<ChanSigner>, ChannelError<ChanSigner>> {
 		if !self.channel_outbound {
 			return Err(ChannelError::Close("Received funding_signed for an inbound channel?"));
 		}
@@ -1587,15 +1492,17 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		let funding_script = self.get_funding_redeemscript();
 
 		let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?;
-		let mut local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
+		let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
 		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]);
 
+		let their_funding_pubkey = &self.their_pubkeys.as_ref().unwrap().funding_pubkey;
+
 		// They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish.
-		secp_check!(self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey.unwrap()), "Invalid funding_signed signature from peer");
+		secp_check!(self.secp_ctx.verify(&local_sighash, &msg.signature, their_funding_pubkey), "Invalid funding_signed signature from peer");
 
-		self.sign_commitment_transaction(&mut local_initial_commitment_tx, &msg.signature);
-		self.channel_monitor.provide_latest_local_commitment_tx_info(local_initial_commitment_tx.clone(), local_keys, self.feerate_per_kw, Vec::new());
-		self.last_local_commitment_txn = vec![local_initial_commitment_tx];
+		self.channel_monitor.provide_latest_local_commitment_tx_info(
+			LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx, &msg.signature, &PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()), their_funding_pubkey),
+			local_keys, self.feerate_per_kw, Vec::new());
 		self.channel_state = ChannelState::FundingSent as u32 | (self.channel_state & (ChannelState::MonitorUpdateFailed as u32));
 		self.cur_local_commitment_transaction_number -= 1;
 
@@ -1606,7 +1513,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 	}
 
-	pub fn funding_locked(&mut self, msg: &msgs::FundingLocked) -> Result<(), ChannelError> {
+	pub fn funding_locked(&mut self, msg: &msgs::FundingLocked) -> Result<(), ChannelError<ChanSigner>> {
 		if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
 			return Err(ChannelError::Close("Peer sent funding_locked when we needed a channel_reestablish"));
 		}
@@ -1677,7 +1584,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		cmp::min(self.value_to_self_msat as i64 - self.get_outbound_pending_htlc_stats().1 as i64, 0) as u64)
 	}
 
-	pub fn update_add_htlc(&mut self, msg: &msgs::UpdateAddHTLC, pending_forward_state: PendingHTLCStatus) -> Result<(), ChannelError> {
+	pub fn update_add_htlc(&mut self, msg: &msgs::UpdateAddHTLC, pending_forward_state: PendingHTLCStatus) -> Result<(), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got add HTLC message when channel was not in an operational state"));
 		}
@@ -1751,7 +1658,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// Marks an outbound HTLC which we have received update_fail/fulfill/malformed
 	#[inline]
-	fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&HTLCSource, ChannelError> {
+	fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&HTLCSource, ChannelError<ChanSigner>> {
 		for htlc in self.pending_outbound_htlcs.iter_mut() {
 			if htlc.htlc_id == htlc_id {
 				match check_preimage {
@@ -1776,7 +1683,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find"))
 	}
 
-	pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<HTLCSource, ChannelError> {
+	pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<HTLCSource, ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state"));
 		}
@@ -1788,7 +1695,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|source| source.clone())
 	}
 
-	pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
+	pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got fail HTLC message when channel was not in an operational state"));
 		}
@@ -1800,7 +1707,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		Ok(())
 	}
 
-	pub fn update_fail_malformed_htlc<'a>(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
+	pub fn update_fail_malformed_htlc<'a>(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got fail malformed HTLC message when channel was not in an operational state"));
 		}
@@ -1812,7 +1719,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		Ok(())
 	}
 
-	pub fn commitment_signed(&mut self, msg: &msgs::CommitmentSigned, fee_estimator: &FeeEstimator) -> Result<(msgs::RevokeAndACK, Option<msgs::CommitmentSigned>, Option<msgs::ClosingSigned>, ChannelMonitor), ChannelError> {
+	pub fn commitment_signed(&mut self, msg: &msgs::CommitmentSigned, fee_estimator: &FeeEstimator) -> Result<(msgs::RevokeAndACK, Option<msgs::CommitmentSigned>, Option<msgs::ClosingSigned>, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got commitment signed message when channel was not in an operational state"));
 		}
@@ -1842,8 +1749,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		};
 		let local_commitment_txid = local_commitment_tx.0.txid();
 		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_commitment_tx.0).sighash_all(&local_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]);
-		log_trace!(self, "Checking commitment tx signature {} by key {} against tx {} with redeemscript {}", log_bytes!(msg.signature.serialize_compact()[..]), log_bytes!(self.their_funding_pubkey.unwrap().serialize()), encode::serialize_hex(&local_commitment_tx.0), encode::serialize_hex(&funding_script));
-		secp_check!(self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey.unwrap()), "Invalid commitment tx signature from peer");
+		log_trace!(self, "Checking commitment tx signature {} by key {} against tx {} with redeemscript {}", log_bytes!(msg.signature.serialize_compact()[..]), log_bytes!(self.their_funding_pubkey().serialize()), encode::serialize_hex(&local_commitment_tx.0), encode::serialize_hex(&funding_script));
+		secp_check!(self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey()), "Invalid commitment tx signature from peer");
 
 		//If channel fee was updated by funder confirm funder can afford the new fee rate when applied to the current local commitment transaction
 		if update_fee {
@@ -1859,26 +1766,15 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("Got wrong number of HTLC signatures from remote"));
 		}
 
-		let mut new_local_commitment_txn = Vec::with_capacity(local_commitment_tx.1 + 1);
-		self.sign_commitment_transaction(&mut local_commitment_tx.0, &msg.signature);
-		new_local_commitment_txn.push(local_commitment_tx.0.clone());
-
 		let mut htlcs_and_sigs = Vec::with_capacity(local_commitment_tx.2.len());
 		for (idx, (htlc, source)) in local_commitment_tx.2.drain(..).enumerate() {
 			if let Some(_) = htlc.transaction_output_index {
-				let mut htlc_tx = self.build_htlc_transaction(&local_commitment_txid, &htlc, true, &local_keys, feerate_per_kw);
+				let htlc_tx = self.build_htlc_transaction(&local_commitment_txid, &htlc, true, &local_keys, feerate_per_kw);
 				let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &local_keys);
 				log_trace!(self, "Checking HTLC tx signature {} by key {} against tx {} with redeemscript {}", log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(local_keys.b_htlc_key.serialize()), encode::serialize_hex(&htlc_tx), encode::serialize_hex(&htlc_redeemscript));
 				let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
 				secp_check!(self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &local_keys.b_htlc_key), "Invalid HTLC tx signature from peer");
-				let htlc_sig = if htlc.offered {
-					let htlc_sig = self.sign_htlc_transaction(&mut htlc_tx, &msg.htlc_signatures[idx], &None, &htlc, &local_keys)?;
-					new_local_commitment_txn.push(htlc_tx);
-					htlc_sig
-				} else {
-					self.create_htlc_tx_signature(&htlc_tx, &htlc, &local_keys)?.1
-				};
-				htlcs_and_sigs.push((htlc, Some((msg.htlc_signatures[idx], htlc_sig)), source));
+				htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
 			} else {
 				htlcs_and_sigs.push((htlc, None, source));
 			}
@@ -1902,7 +1798,11 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		}
 
-		self.channel_monitor.provide_latest_local_commitment_tx_info(local_commitment_tx.0, local_keys, self.feerate_per_kw, htlcs_and_sigs);
+		let their_funding_pubkey = self.their_pubkeys.as_ref().unwrap().funding_pubkey;
+
+		self.channel_monitor.provide_latest_local_commitment_tx_info(
+			LocalCommitmentTransaction::new_missing_local_sig(local_commitment_tx.0, &msg.signature, &PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()), &their_funding_pubkey),
+			local_keys, self.feerate_per_kw, htlcs_and_sigs);
 
 		for htlc in self.pending_inbound_htlcs.iter_mut() {
 			let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state {
@@ -1923,7 +1823,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		self.cur_local_commitment_transaction_number -= 1;
-		self.last_local_commitment_txn = new_local_commitment_txn;
 		// Note that if we need_our_commitment & !AwaitingRemoteRevoke we'll call
 		// send_commitment_no_status_check() next which will reset this to RAAFirst.
 		self.resend_order = RAACommitmentOrder::CommitmentFirst;
@@ -1966,7 +1865,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// Used to fulfill holding_cell_htlcs when we get a remote ack (or implicitly get it by them
 	/// fulfilling or failing the last pending HTLC)
-	fn free_holding_cell_htlcs(&mut self) -> Result<Option<(msgs::CommitmentUpdate, ChannelMonitor)>, ChannelError> {
+	fn free_holding_cell_htlcs(&mut self) -> Result<Option<(msgs::CommitmentUpdate, ChannelMonitor<ChanSigner>)>, ChannelError<ChanSigner>> {
 		assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
 		if self.holding_cell_htlc_updates.len() != 0 || self.holding_cell_update_fee.is_some() {
 			log_trace!(self, "Freeing holding cell with {} HTLC updates{}", self.holding_cell_htlc_updates.len(), if self.holding_cell_update_fee.is_some() { " and a fee update" } else { "" });
@@ -2077,7 +1976,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail,
 	/// generating an appropriate error *after* the channel state has been updated based on the
 	/// revoke_and_ack message.
-	pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, fee_estimator: &FeeEstimator) -> Result<(Option<msgs::CommitmentUpdate>, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, Option<msgs::ClosingSigned>, ChannelMonitor), ChannelError> {
+	pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, fee_estimator: &FeeEstimator) -> Result<(Option<msgs::CommitmentUpdate>, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, Option<msgs::ClosingSigned>, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state"));
 		}
@@ -2287,7 +2186,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		})
 	}
 
-	pub fn send_update_fee_and_commit(&mut self, feerate_per_kw: u64) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitor)>, ChannelError> {
+	pub fn send_update_fee_and_commit(&mut self, feerate_per_kw: u64) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitor<ChanSigner>)>, ChannelError<ChanSigner>> {
 		match self.send_update_fee(feerate_per_kw) {
 			Some(update_fee) => {
 				let (commitment_signed, monitor_update) = self.send_commitment_no_status_check()?;
@@ -2438,7 +2337,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		(raa, commitment_update, order, forwards, failures, needs_broadcast_safe, funding_locked)
 	}
 
-	pub fn update_fee(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::UpdateFee) -> Result<(), ChannelError> {
+	pub fn update_fee(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::UpdateFee) -> Result<(), ChannelError<ChanSigner>> {
 		if self.channel_outbound {
 			return Err(ChannelError::Close("Non-funding remote tried to update channel fee"));
 		}
@@ -2520,7 +2419,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// May panic if some calls other than message-handling calls (which will all Err immediately)
 	/// have been called between remove_uncommitted_htlcs_and_mark_paused and this call.
-	pub fn channel_reestablish(&mut self, msg: &msgs::ChannelReestablish) -> Result<(Option<msgs::FundingLocked>, Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, Option<ChannelMonitor>, RAACommitmentOrder, Option<msgs::Shutdown>), ChannelError> {
+	pub fn channel_reestablish(&mut self, msg: &msgs::ChannelReestablish) -> Result<(Option<msgs::FundingLocked>, Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, Option<ChannelMonitor<ChanSigner>>, RAACommitmentOrder, Option<msgs::Shutdown>), ChannelError<ChanSigner>> {
 		if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
 			// While BOLT 2 doesn't indicate explicitly we should error this channel here, it
 			// almost certainly indicates we are going to end up out-of-sync in some way, so we
@@ -2541,8 +2440,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					}
 					if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.cur_local_commitment_transaction_number {
 						self.channel_monitor.provide_rescue_remote_commitment_tx_info(data_loss.my_current_per_commitment_point);
-						return Err(ChannelError::CloseDelayBroadcast { msg: "We have fallen behind - we have received proof that if we broadcast remote is going to claim our funds - we can't do any automated broadcasting", update: Some(self.channel_monitor.clone())
-					});
+						return Err(ChannelError::CloseDelayBroadcast { msg: "We have fallen behind - we have received proof that if we broadcast remote is going to claim our funds - we can't do any automated broadcasting", update: Some(self.channel_monitor.clone())});
 					}
 				},
 				OptionalField::Absent => {}
@@ -2666,7 +2564,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(proposed_total_fee_satoshis, false);
 		let our_sig = self.local_keys
-			.sign_closing_transaction(self.channel_value_satoshis, &self.get_funding_redeemscript(), &closing_tx, &self.secp_ctx)
+			.sign_closing_transaction(&closing_tx, &self.secp_ctx)
 			.ok();
 		if our_sig.is_none() { return None; }
 
@@ -2678,7 +2576,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		})
 	}
 
-	pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option<msgs::Shutdown>, Option<msgs::ClosingSigned>, Vec<(HTLCSource, PaymentHash)>), ChannelError> {
+	pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option<msgs::Shutdown>, Option<msgs::ClosingSigned>, Vec<(HTLCSource, PaymentHash)>), ChannelError<ChanSigner>> {
 		if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
 			return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish"));
 		}
@@ -2748,6 +2646,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		self.channel_state |= ChannelState::LocalShutdownSent as u32;
 		self.channel_update_count += 1;
+
 		Ok((our_shutdown, self.maybe_propose_first_closing_signed(fee_estimator), dropped_outbound_htlcs))
 	}
 
@@ -2759,7 +2658,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
 
 		let our_funding_key = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()).serialize();
-		let their_funding_key = self.their_funding_pubkey.unwrap().serialize();
+		let their_funding_key = self.their_funding_pubkey().serialize();
 		if our_funding_key[..] < their_funding_key[..] {
 			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
 			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
@@ -2773,7 +2672,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		tx.input[0].witness.push(self.get_funding_redeemscript().into_bytes());
 	}
 
-	pub fn closing_signed(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError> {
+	pub fn closing_signed(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError<ChanSigner>> {
 		if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK {
 			return Err(ChannelError::Close("Remote end sent us a closing_signed before both sides provided a shutdown"));
 		}
@@ -2794,14 +2693,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 		let mut sighash = hash_to_message!(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]);
 
-		match self.secp_ctx.verify(&sighash, &msg.signature, &self.their_funding_pubkey.unwrap()) {
+		let their_funding_pubkey = &self.their_pubkeys.as_ref().unwrap().funding_pubkey;
+
+		match self.secp_ctx.verify(&sighash, &msg.signature, their_funding_pubkey) {
 			Ok(_) => {},
 			Err(_e) => {
 				// The remote end may have decided to revoke their output due to inconsistent dust
 				// limits, so check for that case by re-checking the signature here.
 				closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0;
 				sighash = hash_to_message!(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]);
-				secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, &self.their_funding_pubkey.unwrap()), "Invalid closing tx signature from peer");
+				secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.their_funding_pubkey()), "Invalid closing tx signature from peer");
 			},
 		};
 
@@ -2819,7 +2720,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				let closing_tx_max_weight = Self::get_closing_transaction_weight(&self.get_closing_scriptpubkey(), self.their_shutdown_scriptpubkey.as_ref().unwrap());
 				let (closing_tx, used_total_fee) = self.build_closing_transaction($new_feerate * closing_tx_max_weight / 1000, false);
 				let our_sig = self.local_keys
-					.sign_closing_transaction(self.channel_value_satoshis, &funding_redeemscript, &closing_tx, &self.secp_ctx)
+					.sign_closing_transaction(&closing_tx, &self.secp_ctx)
 					.map_err(|_| ChannelError::Close("External signer refused to sign closing transaction"))?;
 				self.last_sent_closing_fee = Some(($new_feerate, used_total_fee, our_sig.clone()));
 				return Ok((Some(msgs::ClosingSigned {
@@ -2854,7 +2755,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		let our_sig = self.local_keys
-			.sign_closing_transaction(self.channel_value_satoshis, &funding_redeemscript, &closing_tx, &self.secp_ctx)
+			.sign_closing_transaction(&closing_tx, &self.secp_ctx)
 			.map_err(|_| ChannelError::Close("External signer refused to sign closing transaction"))?;
 		self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &our_sig);
 
@@ -2881,11 +2782,11 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	}
 
 	/// May only be called after funding has been initiated (ie is_funding_initiated() is true)
-	pub fn channel_monitor(&self) -> ChannelMonitor {
+	pub fn channel_monitor(&mut self) -> &mut ChannelMonitor<ChanSigner> {
 		if self.channel_state < ChannelState::FundingCreated as u32 {
 			panic!("Can't get a channel monitor until funding has been created");
 		}
-		self.channel_monitor.clone()
+		&mut self.channel_monitor
 	}
 
 	/// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus,
@@ -3251,10 +3152,10 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	}
 
 	/// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
-	fn get_outbound_funding_created_signature(&mut self) -> Result<(Signature, Transaction), ChannelError> {
+	fn get_outbound_funding_created_signature(&mut self) -> Result<(Signature, Transaction), ChannelError<ChanSigner>> {
 		let remote_keys = self.build_remote_transaction_keys()?;
 		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0;
-		Ok((self.local_keys.sign_remote_commitment(self.channel_value_satoshis, &self.get_funding_redeemscript(), self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
+		Ok((self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
 				.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0, remote_initial_commitment_tx))
 	}
 
@@ -3265,7 +3166,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// Note that channel_id changes during this call!
 	/// Do NOT broadcast the funding transaction until after a successful funding_signed call!
 	/// If an Err is returned, it is a ChannelError::Close.
-	pub fn get_outbound_funding_created(&mut self, funding_txo: OutPoint) -> Result<(msgs::FundingCreated, ChannelMonitor), ChannelError> {
+	pub fn get_outbound_funding_created(&mut self, funding_txo: OutPoint) -> Result<(msgs::FundingCreated, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		if !self.channel_outbound {
 			panic!("Tried to create outbound funding_created message on an inbound channel!");
 		}
@@ -3314,7 +3215,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// closing).
 	/// Note that the "channel must be funded" requirement is stricter than BOLT 7 requires - see
 	/// https://github.com/lightningnetwork/lightning-rfc/issues/468
-	pub fn get_channel_announcement(&self, our_node_id: PublicKey, chain_hash: Sha256dHash) -> Result<(msgs::UnsignedChannelAnnouncement, Signature), ChannelError> {
+	pub fn get_channel_announcement(&self, our_node_id: PublicKey, chain_hash: Sha256dHash) -> Result<(msgs::UnsignedChannelAnnouncement, Signature), ChannelError<ChanSigner>> {
 		if !self.config.announced_channel {
 			return Err(ChannelError::Ignore("Channel is not available for public announcements"));
 		}
@@ -3329,13 +3230,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		let our_bitcoin_key = PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key());
 
 		let msg = msgs::UnsignedChannelAnnouncement {
-			features: msgs::GlobalFeatures::new(),
+			features: ChannelFeatures::supported(),
 			chain_hash: chain_hash,
 			short_channel_id: self.get_short_channel_id().unwrap(),
 			node_id_1: if were_node_one { our_node_id } else { self.get_their_node_id() },
 			node_id_2: if were_node_one { self.get_their_node_id() } else { our_node_id },
-			bitcoin_key_1: if were_node_one { our_bitcoin_key } else { self.their_funding_pubkey.unwrap() },
-			bitcoin_key_2: if were_node_one { self.their_funding_pubkey.unwrap() } else { our_bitcoin_key },
+			bitcoin_key_1: if were_node_one { our_bitcoin_key } else { self.their_funding_pubkey().clone() },
+			bitcoin_key_2: if were_node_one { self.their_funding_pubkey().clone() } else { our_bitcoin_key },
 			excess_data: Vec::new(),
 		};
 
@@ -3398,7 +3299,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// HTLCs on the wire or we wouldn't be able to determine what they actually ACK'ed.
 	/// You MUST call send_commitment prior to any other calls on this Channel
 	/// If an Err is returned, it's a ChannelError::Ignore!
-	pub fn send_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result<Option<msgs::UpdateAddHTLC>, ChannelError> {
+	pub fn send_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result<Option<msgs::UpdateAddHTLC>, ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelFunded as u32) {
 			return Err(ChannelError::Ignore("Cannot send HTLC until channel is fully established and we haven't started shutting down"));
 		}
@@ -3475,7 +3376,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// Always returns a ChannelError::Close if an immediately-preceding (read: the
 	/// last call to this Channel) send_htlc returned Ok(Some(_)) and there is an Err.
 	/// May panic if called except immediately after a successful, Ok(Some(_))-returning send_htlc.
-	pub fn send_commitment(&mut self) -> Result<(msgs::CommitmentSigned, ChannelMonitor), ChannelError> {
+	pub fn send_commitment(&mut self) -> Result<(msgs::CommitmentSigned, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
 			panic!("Cannot create commitment tx until channel is fully established");
 		}
@@ -3507,7 +3408,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		self.send_commitment_no_status_check()
 	}
 	/// Only fails in case of bad keys
-	fn send_commitment_no_status_check(&mut self) -> Result<(msgs::CommitmentSigned, ChannelMonitor), ChannelError> {
+	fn send_commitment_no_status_check(&mut self) -> Result<(msgs::CommitmentSigned, ChannelMonitor<ChanSigner>), ChannelError<ChanSigner>> {
 		// We can upgrade the status of some HTLCs that are waiting on a commitment, even if we
 		// fail to generate this, we still are at least at a position where upgrading their status
 		// is acceptable.
@@ -3544,7 +3445,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// Only fails in case of bad keys. Used for channel_reestablish commitment_signed generation
 	/// when we shouldn't change HTLC/channel state.
-	fn send_commitment_no_state_update(&self) -> Result<(msgs::CommitmentSigned, (Transaction, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> {
+	fn send_commitment_no_state_update(&self) -> Result<(msgs::CommitmentSigned, (Transaction, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError<ChanSigner>> {
 		let mut feerate_per_kw = self.feerate_per_kw;
 		if let Some(feerate) = self.pending_update_fee {
 			if self.channel_outbound {
@@ -3562,7 +3463,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				htlcs.push(htlc);
 			}
 
-			let res = self.local_keys.sign_remote_commitment(self.channel_value_satoshis, &self.get_funding_redeemscript(), feerate_per_kw, &remote_commitment_tx.0, &remote_keys, &htlcs, self.our_to_self_delay, &self.secp_ctx)
+			let res = self.local_keys.sign_remote_commitment(feerate_per_kw, &remote_commitment_tx.0, &remote_keys, &htlcs, self.our_to_self_delay, &self.secp_ctx)
 				.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?;
 			signature = res.0;
 			htlc_signatures = res.1;
@@ -3592,7 +3493,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// to send to the remote peer in one go.
 	/// Shorthand for calling send_htlc() followed by send_commitment(), see docs on those for
 	/// more info.
-	pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result<Option<(msgs::UpdateAddHTLC, msgs::CommitmentSigned, ChannelMonitor)>, ChannelError> {
+	pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result<Option<(msgs::UpdateAddHTLC, msgs::CommitmentSigned, ChannelMonitor<ChanSigner>)>, ChannelError<ChanSigner>> {
 		match self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet)? {
 			Some(update_add_htlc) => {
 				let (commitment_signed, monitor_update) = self.send_commitment_no_status_check()?;
@@ -3681,9 +3582,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		self.channel_state = ChannelState::ShutdownComplete as u32;
 		self.channel_update_count += 1;
-		let mut res = Vec::new();
-		mem::swap(&mut res, &mut self.last_local_commitment_txn);
-		(res, dropped_outbound_htlcs)
+		(self.channel_monitor.get_latest_local_commitment_txn(), dropped_outbound_htlcs)
 	}
 }
 
@@ -3873,16 +3772,6 @@ impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
 		self.channel_update_count.write(writer)?;
 		self.feerate_per_kw.write(writer)?;
 
-		(self.last_local_commitment_txn.len() as u64).write(writer)?;
-		for tx in self.last_local_commitment_txn.iter() {
-			if let Err(e) = tx.consensus_encode(&mut WriterWriteAdaptor(writer)) {
-				match e {
-					encode::Error::Io(e) => return Err(e),
-					_ => panic!("last_local_commitment_txn must have been well-formed!"),
-				}
-			}
-		}
-
 		match self.last_sent_closing_fee {
 			Some((feerate, fee, sig)) => {
 				1u8.write(writer)?;
@@ -3910,11 +3799,7 @@ impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
 		self.their_max_accepted_htlcs.write(writer)?;
 		self.minimum_depth.write(writer)?;
 
-		write_option!(self.their_funding_pubkey);
-		write_option!(self.their_revocation_basepoint);
-		write_option!(self.their_payment_basepoint);
-		write_option!(self.their_delayed_payment_basepoint);
-		write_option!(self.their_htlc_basepoint);
+		write_option!(self.their_pubkeys);
 		write_option!(self.their_cur_commitment_point);
 
 		write_option!(self.their_prev_commitment_point);
@@ -4041,15 +3926,6 @@ impl<R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
 		let channel_update_count = Readable::read(reader)?;
 		let feerate_per_kw = Readable::read(reader)?;
 
-		let last_local_commitment_txn_count: u64 = Readable::read(reader)?;
-		let mut last_local_commitment_txn = Vec::with_capacity(cmp::min(last_local_commitment_txn_count as usize, OUR_MAX_HTLCS as usize*2 + 1));
-		for _ in 0..last_local_commitment_txn_count {
-			last_local_commitment_txn.push(match Transaction::consensus_decode(reader.by_ref()) {
-				Ok(tx) => tx,
-				Err(_) => return Err(DecodeError::InvalidValue),
-			});
-		}
-
 		let last_sent_closing_fee = match <u8 as Readable<R>>::read(reader)? {
 			0 => None,
 			1 => Some((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?)),
@@ -4073,11 +3949,7 @@ impl<R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
 		let their_max_accepted_htlcs = Readable::read(reader)?;
 		let minimum_depth = Readable::read(reader)?;
 
-		let their_funding_pubkey = Readable::read(reader)?;
-		let their_revocation_basepoint = Readable::read(reader)?;
-		let their_payment_basepoint = Readable::read(reader)?;
-		let their_delayed_payment_basepoint = Readable::read(reader)?;
-		let their_htlc_basepoint = Readable::read(reader)?;
+		let their_pubkeys = Readable::read(reader)?;
 		let their_cur_commitment_point = Readable::read(reader)?;
 
 		let their_prev_commitment_point = Readable::read(reader)?;
@@ -4086,7 +3958,7 @@ impl<R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
 		let their_shutdown_scriptpubkey = Readable::read(reader)?;
 		let (monitor_last_block, channel_monitor) = ReadableArgs::read(reader, logger.clone())?;
 		// We drop the ChannelMonitor's last block connected hash cause we don't actually bother
-		// doing full block connection operations on the internal CHannelMonitor copies
+		// doing full block connection operations on the internal ChannelMonitor copies
 		if monitor_last_block != last_block_connected {
 			return Err(DecodeError::InvalidValue);
 		}
@@ -4132,8 +4004,6 @@ impl<R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
 			#[cfg(debug_assertions)]
 			max_commitment_tx_output_remote: ::std::sync::Mutex::new((0, 0)),
 
-			last_local_commitment_txn,
-
 			last_sent_closing_fee,
 
 			funding_tx_confirmed_in,
@@ -4152,11 +4022,7 @@ impl<R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>> ReadableArgs<R,
 			their_max_accepted_htlcs,
 			minimum_depth,
 
-			their_funding_pubkey,
-			their_revocation_basepoint,
-			their_payment_basepoint,
-			their_delayed_payment_basepoint,
-			their_htlc_basepoint,
+			their_pubkeys,
 			their_cur_commitment_point,
 
 			their_prev_commitment_point,
@@ -4186,13 +4052,14 @@ mod tests {
 	use ln::channel::{Channel,ChannelKeys,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,TxCreationKeys};
 	use ln::channel::MAX_FUNDING_SATOSHIS;
 	use ln::chan_utils;
+	use ln::chan_utils::{LocalCommitmentTransaction, ChannelPublicKeys};
 	use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
 	use chain::keysinterface::{InMemoryChannelKeys, KeysInterface};
 	use chain::transaction::OutPoint;
 	use util::config::UserConfig;
 	use util::test_utils;
 	use util::logger::Logger;
-	use secp256k1::{Secp256k1,Message,Signature};
+	use secp256k1::{Secp256k1, Message, Signature, All};
 	use secp256k1::key::{SecretKey,PublicKey};
 	use bitcoin_hashes::sha256::Hash as Sha256;
 	use bitcoin_hashes::sha256d::Hash as Sha256dHash;
@@ -4235,11 +4102,17 @@ mod tests {
 			PublicKey::from_secret_key(&secp_ctx, &channel_close_key)
 		}
 
-		fn get_channel_keys(&self, _inbound: bool) -> InMemoryChannelKeys { self.chan_keys.clone() }
+		fn get_channel_keys(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemoryChannelKeys {
+			self.chan_keys.clone()
+		}
 		fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) { panic!(); }
 		fn get_channel_id(&self) -> [u8; 32] { [0; 32] }
 	}
 
+	fn public_from_secret_hex(secp_ctx: &Secp256k1<All>, hex: &str) -> PublicKey {
+		PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode(hex).unwrap()[..]).unwrap())
+	}
+
 	#[test]
 	fn outbound_commitment_test() {
 		// Test vectors from BOLT 3 Appendix C:
@@ -4247,16 +4120,19 @@ mod tests {
 		let logger : Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 		let secp_ctx = Secp256k1::new();
 
-		let chan_keys = InMemoryChannelKeys {
-			funding_key: SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
-			payment_base_key: SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
-			delayed_payment_base_key: SecretKey::from_slice(&hex::decode("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
-			htlc_base_key: SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
+		let chan_keys = InMemoryChannelKeys::new(
+			&secp_ctx,
+			SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
+			SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
+			SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
+			SecretKey::from_slice(&hex::decode("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
+			SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
 
 			// These aren't set in the test vectors:
-			revocation_base_key: SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
-			commitment_seed: [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
-		};
+			[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
+			7000000000,
+		);
+
 		assert_eq!(PublicKey::from_secret_key(&secp_ctx, chan_keys.funding_key()).serialize()[..],
 				hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
 		let keys_provider: Arc<KeysInterface<ChanKeySigner = InMemoryChannelKeys>> = Arc::new(Keys { chan_keys });
@@ -4271,19 +4147,22 @@ mod tests {
 		let funding_info = OutPoint::new(Sha256dHash::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), 0);
 		chan.channel_monitor.set_funding_info((funding_info, Script::new()));
 
-		chan.their_payment_basepoint = Some(PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode("4444444444444444444444444444444444444444444444444444444444444444").unwrap()[..]).unwrap()));
-		assert_eq!(chan.their_payment_basepoint.unwrap().serialize()[..],
-				hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
+		let their_pubkeys = ChannelPublicKeys {
+			funding_pubkey: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
+			revocation_basepoint: PublicKey::from_slice(&hex::decode("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap(),
+			payment_basepoint: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444"),
+			delayed_payment_basepoint: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
+			htlc_basepoint: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444")
+		};
 
-		chan.their_funding_pubkey = Some(PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode("1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13").unwrap()[..]).unwrap()));
-		assert_eq!(chan.their_funding_pubkey.unwrap().serialize()[..],
-				hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
+		assert_eq!(their_pubkeys.payment_basepoint.serialize()[..],
+		           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
-		chan.their_htlc_basepoint = Some(PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode("4444444444444444444444444444444444444444444444444444444444444444").unwrap()[..]).unwrap()));
-		assert_eq!(chan.their_htlc_basepoint.unwrap().serialize()[..],
-				hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
+		assert_eq!(their_pubkeys.funding_pubkey.serialize()[..],
+		           hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
 
-		chan.their_revocation_basepoint = Some(PublicKey::from_slice(&hex::decode("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap());
+		assert_eq!(their_pubkeys.htlc_basepoint.serialize()[..],
+		           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
 		// We can't just use build_local_transaction_keys here as the per_commitment_secret is not
 		// derived from a commitment_seed, so instead we copy it here and call
@@ -4292,7 +4171,9 @@ mod tests {
 		let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
 		let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
 		let htlc_basepoint = PublicKey::from_secret_key(&secp_ctx, chan.local_keys.htlc_base_key());
-		let keys = TxCreationKeys::new(&secp_ctx, &per_commitment_point, &delayed_payment_base, &htlc_basepoint, &chan.their_revocation_basepoint.unwrap(), &chan.their_payment_basepoint.unwrap(), &chan.their_htlc_basepoint.unwrap()).unwrap();
+		let keys = TxCreationKeys::new(&secp_ctx, &per_commitment_point, &delayed_payment_base, &htlc_basepoint, &their_pubkeys.revocation_basepoint, &their_pubkeys.payment_basepoint, &their_pubkeys.htlc_basepoint).unwrap();
+
+		chan.their_pubkeys = Some(their_pubkeys);
 
 		let mut unsigned_tx: (Transaction, Vec<HTLCOutputInCommitment>);
 
@@ -4305,13 +4186,15 @@ mod tests {
 						.collect();
 					(res.0, htlcs)
 				};
+				let redeemscript = chan.get_funding_redeemscript();
 				let their_signature = Signature::from_der(&hex::decode($their_sig_hex).unwrap()[..]).unwrap();
-				let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &chan.get_funding_redeemscript(), chan.channel_value_satoshis)[..]).unwrap();
-				secp_ctx.verify(&sighash, &their_signature, &chan.their_funding_pubkey.unwrap()).unwrap();
+				let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &redeemscript, chan.channel_value_satoshis)[..]).unwrap();
+				secp_ctx.verify(&sighash, &their_signature, chan.their_funding_pubkey()).unwrap();
 
-				chan.sign_commitment_transaction(&mut unsigned_tx.0, &their_signature);
+				let mut localtx = LocalCommitmentTransaction::new_missing_local_sig(unsigned_tx.0.clone(), &their_signature, &PublicKey::from_secret_key(&secp_ctx, chan.local_keys.funding_key()), chan.their_funding_pubkey());
+				localtx.add_local_sig(chan.local_keys.funding_key(), &redeemscript, chan.channel_value_satoshis, &chan.secp_ctx);
 
-				assert_eq!(serialize(&unsigned_tx.0)[..],
+				assert_eq!(serialize(localtx.with_valid_witness())[..],
 						hex::decode($tx_hex).unwrap()[..]);
 			};
 		}
@@ -4338,7 +4221,7 @@ mod tests {
 					assert!(preimage.is_some());
 				}
 
-				chan.sign_htlc_transaction(&mut htlc_tx, &remote_signature, &preimage, &htlc, &keys).unwrap();
+				chan_utils::sign_htlc_transaction(&mut htlc_tx, &remote_signature, &preimage, &htlc, &keys.a_htlc_key, &keys.b_htlc_key, &keys.revocation_key, &keys.per_commitment_point, chan.local_keys.htlc_base_key(), &chan.secp_ctx).unwrap();
 				assert_eq!(serialize(&htlc_tx)[..],
 						hex::decode($tx_hex).unwrap()[..]);
 			};