Add utility function to add a change output to a transaction
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index 3c58e9a2888d7b7cea4eda3376648a72fd0abd95..91c2a3c50c3531b813164eb4dc8c88287c4ce296 100644 (file)
@@ -43,9 +43,9 @@ use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::transaction::{OutPoint, TransactionData};
-use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
+use chain::keysinterface::{SpendableOutputDescriptor, StaticCounterpartyPaymentOutputDescriptor, DynamicP2WSHOutputDescriptor, ChannelKeys, KeysInterface};
 use util::logger::Logger;
-use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
+use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
 use util::byte_utils;
 use util::events::Event;
 
@@ -56,7 +56,7 @@ use std::io::Error;
 
 /// An update generated by the underlying Channel itself which contains some new information the
 /// ChannelMonitor should be made aware of.
-#[cfg_attr(any(test, feature = "_test_utils"), derive(PartialEq))]
+#[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
 #[derive(Clone)]
 #[must_use]
 pub struct ChannelMonitorUpdate {
@@ -174,7 +174,7 @@ pub enum ChannelMonitorUpdateErr {
 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
 /// corrupted.
 /// Contains a developer-readable error message.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct MonitorUpdateError(pub &'static str);
 
 /// An event to be processed by the ChannelManager.
@@ -485,7 +485,7 @@ enum OnchainEvent {
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-#[cfg_attr(any(test, feature = "_test_utils"), derive(PartialEq))]
+#[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
 #[derive(Clone)]
 pub(crate) enum ChannelMonitorUpdateStep {
        LatestHolderCommitmentTXInfo {
@@ -617,6 +617,12 @@ impl Readable for ChannelMonitorUpdateStep {
 /// 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 (Sha256dHash, 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<ChanSigner: ChannelKeys> {
        latest_update_id: u64,
        commitment_transaction_number_obscure_factor: u64,
@@ -626,7 +632,7 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        counterparty_payment_script: Script,
        shutdown_script: Script,
 
-       key_derivation_params: (u64, u64),
+       channel_keys_id: [u8; 32],
        holder_revocation_basepoint: PublicKey,
        funding_info: (OutPoint, Script),
        current_counterparty_commitment_txid: Option<Txid>,
@@ -722,7 +728,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                        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.key_derivation_params != other.key_derivation_params ||
+                       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 ||
@@ -755,15 +761,8 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
        }
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
-       /// Writes this monitor into the given writer, suitable for writing to disk.
-       ///
-       /// Note that the deserializer is only implemented for (Sha256dHash, 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 fn serialize_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
                //TODO: We still write out all the serialization here manually instead of using the fancy
                //serialization framework we have, we should migrate things over to it.
                writer.write_all(&[SERIALIZATION_VERSION; 1])?;
@@ -787,7 +786,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
                self.counterparty_payment_script.write(writer)?;
                self.shutdown_script.write(writer)?;
 
-               self.key_derivation_params.write(writer)?;
+               self.channel_keys_id.write(writer)?;
                self.holder_revocation_basepoint.write(writer)?;
                writer.write_all(&self.funding_info.0.txid[..])?;
                writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
@@ -968,9 +967,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
                let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
 
-               let key_derivation_params = keys.key_derivation_params();
+               let channel_keys_id = keys.channel_keys_id();
                let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
-               let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys, channel_parameters.clone());
 
                let secp_ctx = Secp256k1::new();
 
@@ -992,7 +990,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        };
                        (holder_commitment_tx, trusted_tx.commitment_number())
                };
-               onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx);
+
+               let onchain_tx_handler =
+                       OnchainTxHandler::new(destination_script.clone(), keys, channel_parameters.clone(), initial_holder_commitment_tx);
 
                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())]);
@@ -1006,7 +1006,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        counterparty_payment_script,
                        shutdown_script,
 
-                       key_derivation_params,
+                       channel_keys_id,
                        holder_revocation_basepoint,
                        funding_info,
                        current_counterparty_commitment_txid: None,
@@ -1726,28 +1726,26 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
                log_trace!(logger, "Getting signed latest holder commitment transaction!");
                self.holder_tx_signed = true;
-               if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
-                       let txid = commitment_tx.txid();
-                       let mut res = vec![commitment_tx];
-                       for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
-                               if let Some(vout) = htlc.0.transaction_output_index {
-                                       let preimage = if !htlc.0.offered {
-                                                       if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
-                                                               // We can't build an HTLC-Success transaction without the preimage
-                                                               continue;
-                                                       }
-                                               } else { None };
-                                       if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
-                                                       &::bitcoin::OutPoint { txid, vout }, &preimage) {
-                                               res.push(htlc_tx);
+               let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
+               let txid = commitment_tx.txid();
+               let mut res = vec![commitment_tx];
+               for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
+                       if let Some(vout) = htlc.0.transaction_output_index {
+                               let preimage = if !htlc.0.offered {
+                                       if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
+                                               // We can't build an HTLC-Success transaction without the preimage
+                                               continue;
                                        }
+                               } else { None };
+                               if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
+                                       &::bitcoin::OutPoint { txid, vout }, &preimage) {
+                                       res.push(htlc_tx);
                                }
                        }
-                       // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
-                       // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
-                       return res
                }
-               Vec::new()
+               // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
+               // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
+               return res;
        }
 
        /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
@@ -1756,26 +1754,24 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
        pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
                log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
-               if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
-                       let txid = commitment_tx.txid();
-                       let mut res = vec![commitment_tx];
-                       for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
-                               if let Some(vout) = htlc.0.transaction_output_index {
-                                       let preimage = if !htlc.0.offered {
-                                                       if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
-                                                               // We can't build an HTLC-Success transaction without the preimage
-                                                               continue;
-                                                       }
-                                               } else { None };
-                                       if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
-                                                       &::bitcoin::OutPoint { txid, vout }, &preimage) {
-                                               res.push(htlc_tx);
+               let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
+               let txid = commitment_tx.txid();
+               let mut res = vec![commitment_tx];
+               for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
+                       if let Some(vout) = htlc.0.transaction_output_index {
+                               let preimage = if !htlc.0.offered {
+                                       if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
+                                               // We can't build an HTLC-Success transaction without the preimage
+                                               continue;
                                        }
+                               } else { None };
+                               if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
+                                       &::bitcoin::OutPoint { txid, vout }, &preimage) {
+                                       res.push(htlc_tx);
                                }
                        }
-                       return res
                }
-               Vec::new()
+               return res
        }
 
        /// Processes transactions in a newly connected block, which may result in any of the following:
@@ -1854,15 +1850,14 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                }
                if should_broadcast {
                        self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
-                       if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
-                               self.holder_tx_signed = true;
-                               let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
-                               let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
-                               if !new_outputs.is_empty() {
-                                       watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
-                               }
-                               claimable_outpoints.append(&mut new_outpoints);
+                       let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
+                       self.holder_tx_signed = true;
+                       let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
+                       let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
+                       if !new_outputs.is_empty() {
+                               watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
                        }
+                       claimable_outpoints.append(&mut new_outpoints);
                }
                if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
                        for ev in events {
@@ -2206,22 +2201,24 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                break;
                        } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
                                if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
-                                       spendable_output =  Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
+                                       spendable_output =  Some(SpendableOutputDescriptor::DynamicOutputP2WSH(DynamicP2WSHOutputDescriptor {
                                                outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                                per_commitment_point: broadcasted_holder_revokable_script.1,
                                                to_self_delay: self.on_holder_tx_csv,
                                                output: outp.clone(),
-                                               key_derivation_params: self.key_derivation_params,
                                                revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
-                                       });
+                                               channel_keys_id: self.channel_keys_id,
+                                               channel_value_satoshis: self.channel_value_satoshis,
+                                       }));
                                        break;
                                }
                        } else if self.counterparty_payment_script == outp.script_pubkey {
-                               spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
+                               spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment(StaticCounterpartyPaymentOutputDescriptor {
                                        outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                        output: outp.clone(),
-                                       key_derivation_params: self.key_derivation_params,
-                               });
+                                       channel_keys_id: self.channel_keys_id,
+                                       channel_value_satoshis: self.channel_value_satoshis,
+                               }));
                                break;
                        } else if outp.script_pubkey == self.shutdown_script {
                                spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
@@ -2302,8 +2299,9 @@ pub trait Persist<Keys: ChannelKeys>: Send + Sync {
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
 
-impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>> ReadableArgs<&'a K>
+               for (BlockHash, ChannelMonitor<ChanSigner>) {
+       fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
                macro_rules! unwrap_obj {
                        ($key: expr) => {
                                match $key {
@@ -2336,7 +2334,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                let counterparty_payment_script = Readable::read(reader)?;
                let shutdown_script = Readable::read(reader)?;
 
-               let key_derivation_params = Readable::read(reader)?;
+               let channel_keys_id = Readable::read(reader)?;
                let holder_revocation_basepoint = Readable::read(reader)?;
                // Technically this can fail and serialize fail a round-trip, but only for serialization of
                // barely-init'd ChannelMonitors that we can't do anything with.
@@ -2537,7 +2535,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                                return Err(DecodeError::InvalidValue);
                        }
                }
-               let onchain_tx_handler = Readable::read(reader)?;
+               let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
 
                let lockdown_from_offchain = Readable::read(reader)?;
                let holder_tx_signed = Readable::read(reader)?;
@@ -2551,7 +2549,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor
                        counterparty_payment_script,
                        shutdown_script,
 
-                       key_derivation_params,
+                       channel_keys_id,
                        holder_revocation_basepoint,
                        funding_info,
                        current_counterparty_commitment_txid,
@@ -2679,7 +2677,7 @@ mod tests {
                        SecretKey::from_slice(&[41; 32]).unwrap(),
                        [41; 32],
                        0,
-                       (0, 0)
+                       [0; 32]
                );
 
                let counterparty_pubkeys = ChannelPublicKeys {