Generate Events from ChannelMonitor to indicate spendable ouputs
authorAntoine Riard <ariard@student.42.fr>
Fri, 19 Oct 2018 02:44:40 +0000 (02:44 +0000)
committerMatt Corallo <git@bluematt.me>
Sat, 27 Oct 2018 13:34:28 +0000 (09:34 -0400)
Extend KeyStorage with delayed_payment_base_key and per_commitment_point
to derive local_delayed private key

src/chain/keysinterface.rs [new file with mode: 0644]
src/chain/mod.rs
src/ln/channel.rs
src/ln/channelmonitor.rs
src/ln/peer_handler.rs
src/util/events.rs

diff --git a/src/chain/keysinterface.rs b/src/chain/keysinterface.rs
new file mode 100644 (file)
index 0000000..bab21fd
--- /dev/null
@@ -0,0 +1,36 @@
+//! keysinterface provides keys into rust-lightning and defines some useful enums which describe
+//! spendable on-chain outputs which the user owns and is responsible for using just as any other
+//! on-chain output which is theirs.
+
+use bitcoin::blockdata::transaction::{OutPoint, TxOut};
+use bitcoin::blockdata::script::Script;
+
+use secp256k1::key::SecretKey;
+
+/// When on-chain outputs are created by rust-lightning an event is generated which informs the
+/// user thereof. This enum describes the format of the output and provides the OutPoint.
+pub enum SpendableOutputDescriptor {
+       /// Outpoint with an output to a script which was provided via KeysInterface, thus you should
+       /// have stored somewhere how to spend script_pubkey!
+       /// Outputs from a justice tx, claim tx or preimage tx
+       StaticOutput {
+               /// The outpoint spendable by user wallet
+               outpoint: OutPoint,
+               /// The output which is referenced by the given outpoint
+               output: TxOut,
+       },
+       /// Outpoint commits to a P2WSH, should be spend by the following witness :
+       /// <local_delayedsig> 0 <witnessScript>
+       /// With input nSequence set to_self_delay.
+       /// Outputs from a HTLC-Success/Timeout tx
+       DynamicOutput {
+               /// Outpoint spendable by user wallet
+               outpoint: OutPoint,
+               /// local_delayedkey = delayed_payment_basepoint_secret + SHA256(per_commitment_point || delayed_payment_basepoint
+               local_delayedkey: SecretKey,
+               /// witness redeemScript encumbering output
+               witness_script: Script,
+               /// nSequence input must commit to self_delay to satisfy script's OP_CSV
+               to_self_delay: u16,
+       }
+}
index 95fdce8172745372e2ea57bb954106425b13e24f..ffa5ed968be4d62e391f613a337f464b37d31b27 100644 (file)
@@ -2,3 +2,4 @@
 
 pub mod chaininterface;
 pub mod transaction;
+pub mod keysinterface;
index 6b1511387d61d0048c8e8b1b29b81378df81c1b3..e8d7f538fd900719450f58c77fec9d8b9f4463cf 100644 (file)
@@ -489,8 +489,7 @@ impl Channel {
                let secp_ctx = Secp256k1::new();
                let our_channel_monitor_claim_key_hash = Hash160::from_data(&PublicKey::from_secret_key(&secp_ctx, &chan_keys.channel_monitor_claim_key).serialize());
                let our_channel_monitor_claim_script = Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&our_channel_monitor_claim_key_hash[..]).into_script();
-               let channel_monitor = ChannelMonitor::new(&chan_keys.revocation_base_key,
-                                                         &PublicKey::from_secret_key(&secp_ctx, &chan_keys.delayed_payment_base_key),
+               let channel_monitor = ChannelMonitor::new(&chan_keys.revocation_base_key, &chan_keys.delayed_payment_base_key,
                                                          &chan_keys.htlc_base_key,
                                                          BREAKDOWN_TIMEOUT, our_channel_monitor_claim_script);
 
@@ -651,8 +650,7 @@ impl Channel {
                let secp_ctx = Secp256k1::new();
                let our_channel_monitor_claim_key_hash = Hash160::from_data(&PublicKey::from_secret_key(&secp_ctx, &chan_keys.channel_monitor_claim_key).serialize());
                let our_channel_monitor_claim_script = Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&our_channel_monitor_claim_key_hash[..]).into_script();
-               let mut channel_monitor = ChannelMonitor::new(&chan_keys.revocation_base_key,
-                                                             &PublicKey::from_secret_key(&secp_ctx, &chan_keys.delayed_payment_base_key),
+               let mut channel_monitor = ChannelMonitor::new(&chan_keys.revocation_base_key, &chan_keys.delayed_payment_base_key,
                                                              &chan_keys.htlc_base_key,
                                                              BREAKDOWN_TIMEOUT, our_channel_monitor_claim_script);
                channel_monitor.set_their_base_keys(&msg.htlc_basepoint, &msg.delayed_payment_basepoint);
index 60cb9c91583d604fa8fa464bd0b0f60790c48005..5adfe926ce278f8d7c9858f00c13823354340714 100644 (file)
@@ -30,13 +30,14 @@ use ln::chan_utils;
 use ln::chan_utils::HTLCOutputInCommitment;
 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
 use chain::transaction::OutPoint;
+use chain::keysinterface::SpendableOutputDescriptor;
 use util::ser::{Readable, Writer};
 use util::sha2::Sha256;
-use util::byte_utils;
+use util::{byte_utils, events};
 
 use std::collections::HashMap;
 use std::sync::{Arc,Mutex};
-use std::{hash,cmp};
+use std::{hash,cmp, mem};
 
 /// An error enum representing a failure to persist a channel monitor update.
 #[derive(Clone)]
@@ -106,20 +107,31 @@ pub struct SimpleManyChannelMonitor<Key> {
        #[cfg(not(test))]
        monitors: Mutex<HashMap<Key, ChannelMonitor>>,
        chain_monitor: Arc<ChainWatchInterface>,
-       broadcaster: Arc<BroadcasterInterface>
+       broadcaster: Arc<BroadcasterInterface>,
+       pending_events: Mutex<Vec<events::Event>>,
 }
 
 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
        fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
-               let monitors = self.monitors.lock().unwrap();
-               for monitor in monitors.values() {
-                       let txn_outputs = monitor.block_connected(txn_matched, height, &*self.broadcaster);
-                       for (ref txid, ref outputs) in txn_outputs {
-                               for (idx, output) in outputs.iter().enumerate() {
-                                       self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
+               let mut new_events: Vec<events::Event> = Vec::with_capacity(0);
+               {
+                       let monitors = self.monitors.lock().unwrap();
+                       for monitor in monitors.values() {
+                               let (txn_outputs, spendable_outputs) = monitor.block_connected(txn_matched, height, &*self.broadcaster);
+                               if spendable_outputs.len() > 0 {
+                                       new_events.push(events::Event::SpendableOutputs {
+                                               outputs: spendable_outputs,
+                                       });
+                               }
+                               for (ref txid, ref outputs) in txn_outputs {
+                                       for (idx, output) in outputs.iter().enumerate() {
+                                               self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
+                                       }
                                }
                        }
                }
+               let mut pending_events = self.pending_events.lock().unwrap();
+               pending_events.append(&mut new_events);
        }
 
        fn block_disconnected(&self, _: &BlockHeader) { }
@@ -132,7 +144,8 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key>
                let res = Arc::new(SimpleManyChannelMonitor {
                        monitors: Mutex::new(HashMap::new()),
                        chain_monitor,
-                       broadcaster
+                       broadcaster,
+                       pending_events: Mutex::new(Vec::new()),
                });
                let weak_res = Arc::downgrade(&res);
                res.chain_monitor.register_listener(weak_res);
@@ -167,6 +180,15 @@ impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
        }
 }
 
+impl<Key : Send + cmp::Eq + hash::Hash> events::EventsProvider for SimpleManyChannelMonitor<Key> {
+       fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
+               let mut pending_events = self.pending_events.lock().unwrap();
+               let mut ret = Vec::new();
+               mem::swap(&mut ret, &mut *pending_events);
+               ret
+       }
+}
+
 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 /// instead claiming it in its own individual transaction.
 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
@@ -185,6 +207,9 @@ enum KeyStorage {
        PrivMode {
                revocation_base_key: SecretKey,
                htlc_base_key: SecretKey,
+               delayed_payment_base_key: SecretKey,
+               prev_latest_per_commitment_point: Option<PublicKey>,
+               latest_per_commitment_point: Option<PublicKey>,
        },
        SigsMode {
                revocation_base_key: PublicKey,
@@ -219,7 +244,6 @@ pub struct ChannelMonitor {
        commitment_transaction_number_obscure_factor: u64,
 
        key_storage: KeyStorage,
-       delayed_payment_base_key: PublicKey,
        their_htlc_base_key: Option<PublicKey>,
        their_delayed_payment_base_key: Option<PublicKey>,
        // first is the idx of the first of the two revocation points
@@ -261,7 +285,6 @@ impl Clone for ChannelMonitor {
                        commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 
                        key_storage: self.key_storage.clone(),
-                       delayed_payment_base_key: self.delayed_payment_base_key.clone(),
                        their_htlc_base_key: self.their_htlc_base_key.clone(),
                        their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
                        their_cur_revocation_points: self.their_cur_revocation_points.clone(),
@@ -293,7 +316,6 @@ impl PartialEq for ChannelMonitor {
                if self.funding_txo != other.funding_txo ||
                        self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
                        self.key_storage != other.key_storage ||
-                       self.delayed_payment_base_key != other.delayed_payment_base_key ||
                        self.their_htlc_base_key != other.their_htlc_base_key ||
                        self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
                        self.their_cur_revocation_points != other.their_cur_revocation_points ||
@@ -321,7 +343,7 @@ impl PartialEq for ChannelMonitor {
 }
 
 impl ChannelMonitor {
-       pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
+       pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
                ChannelMonitor {
                        funding_txo: None,
                        commitment_transaction_number_obscure_factor: 0,
@@ -329,8 +351,10 @@ impl ChannelMonitor {
                        key_storage: KeyStorage::PrivMode {
                                revocation_base_key: revocation_base_key.clone(),
                                htlc_base_key: htlc_base_key.clone(),
+                               delayed_payment_base_key: delayed_payment_base_key.clone(),
+                               prev_latest_per_commitment_point: None,
+                               latest_per_commitment_point: None,
                        },
-                       delayed_payment_base_key: delayed_payment_base_key.clone(),
                        their_htlc_base_key: None,
                        their_delayed_payment_base_key: None,
                        their_cur_revocation_points: None,
@@ -469,6 +493,8 @@ impl ChannelMonitor {
        /// is important that any clones of this channel monitor (including remote clones) by kept
        /// up-to-date as our local commitment transaction is updated.
        /// Panics if set_their_to_self_delay has never been called.
+       /// Also update KeyStorage with latest local per_commitment_point to derive local_delayedkey in
+       /// case of onchain HTLC tx
        pub(super) fn provide_latest_local_commitment_tx_info(&mut self, signed_commitment_tx: Transaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>) {
                assert!(self.their_to_self_delay.is_some());
                self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
@@ -482,6 +508,15 @@ impl ChannelMonitor {
                        feerate_per_kw,
                        htlc_outputs,
                });
+               self.key_storage = if let KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, prev_latest_per_commitment_point: _, ref latest_per_commitment_point } = self.key_storage {
+                       KeyStorage::PrivMode {
+                               revocation_base_key: *revocation_base_key,
+                               htlc_base_key: *htlc_base_key,
+                               delayed_payment_base_key: *delayed_payment_base_key,
+                               prev_latest_per_commitment_point: *latest_per_commitment_point,
+                               latest_per_commitment_point: Some(local_keys.per_commitment_point),
+                       }
+               } else { unimplemented!(); };
        }
 
        /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
@@ -587,15 +622,28 @@ impl ChannelMonitor {
                writer.write_all(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor))?;
 
                match self.key_storage {
-                       KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
+                       KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref prev_latest_per_commitment_point, ref latest_per_commitment_point } => {
                                writer.write_all(&[0; 1])?;
                                writer.write_all(&revocation_base_key[..])?;
                                writer.write_all(&htlc_base_key[..])?;
+                               writer.write_all(&delayed_payment_base_key[..])?;
+                               if let Some(ref prev_latest_per_commitment_point) = *prev_latest_per_commitment_point {
+                                       writer.write_all(&[1; 1])?;
+                                       writer.write_all(&prev_latest_per_commitment_point.serialize())?;
+                               } else {
+                                       writer.write_all(&[0; 1])?;
+                               }
+                               if let Some(ref latest_per_commitment_point) = *latest_per_commitment_point {
+                                       writer.write_all(&[1; 1])?;
+                                       writer.write_all(&latest_per_commitment_point.serialize())?;
+                               } else {
+                                       writer.write_all(&[0; 1])?;
+                               }
+
                        },
                        KeyStorage::SigsMode { .. } => unimplemented!(),
                }
 
-               writer.write_all(&self.delayed_payment_base_key.serialize())?;
                writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
                writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
 
@@ -748,11 +796,12 @@ impl ChannelMonitor {
        /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
        /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
        /// HTLC-Success/HTLC-Timeout transactions.
-       fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
+       fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>), Vec<SpendableOutputDescriptor>) {
                // Most secp and related errors trying to create keys means we have no hope of constructing
                // a spend transaction...so we return no transactions to broadcast
                let mut txn_to_broadcast = Vec::new();
                let mut watch_outputs = Vec::new();
+               let mut spendable_outputs = Vec::new();
 
                let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
                let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
@@ -761,7 +810,7 @@ impl ChannelMonitor {
                        ( $thing : expr ) => {
                                match $thing {
                                        Ok(a) => a,
-                                       Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs))
+                                       Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs)
                                }
                        };
                }
@@ -771,7 +820,7 @@ impl ChannelMonitor {
                        let secret = self.get_secret(commitment_number).unwrap();
                        let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
                        let (revocation_pubkey, b_htlc_key) = match self.key_storage {
-                               KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
+                               KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, .. } => {
                                        let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
                                        (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
                                        ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
@@ -784,7 +833,7 @@ impl ChannelMonitor {
                        };
                        let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
                        let a_htlc_key = match self.their_htlc_base_key {
-                               None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
+                               None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs),
                                Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
                        };
 
@@ -851,7 +900,7 @@ impl ChannelMonitor {
                                        if htlc.transaction_output_index as usize >= tx.output.len() ||
                                                        tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
                                                        tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
-                                               return (txn_to_broadcast, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
+                                               return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user
                                        }
                                        let input = TxIn {
                                                previous_output: BitcoinOutPoint {
@@ -889,7 +938,7 @@ impl ChannelMonitor {
                                watch_outputs.append(&mut tx.output.clone());
                                self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
                        }
-                       if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
+                       if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); } // Nothing to be done...probably a false positive/local tx
 
                        let outputs = vec!(TxOut {
                                script_pubkey: self.destination_script.clone(),
@@ -910,6 +959,10 @@ impl ChannelMonitor {
                                sign_input!(sighash_parts, input, htlc_idx, value);
                        }
 
+                       spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
+                               outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
+                               output: spend_tx.output[0].clone(),
+                       });
                        txn_to_broadcast.push(spend_tx);
                } else if let Some(per_commitment_data) = per_commitment_option {
                        // While this isn't useful yet, there is a potential race where if a counterparty
@@ -930,7 +983,7 @@ impl ChannelMonitor {
                                        } else { None };
                                if let Some(revocation_point) = revocation_point_option {
                                        let (revocation_pubkey, b_htlc_key) = match self.key_storage {
-                                               KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
+                                               KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, .. } => {
                                                        (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
                                                        ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
                                                },
@@ -940,7 +993,7 @@ impl ChannelMonitor {
                                                },
                                        };
                                        let a_htlc_key = match self.their_htlc_base_key {
-                                               None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
+                                               None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs),
                                                Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
                                        };
 
@@ -998,12 +1051,16 @@ impl ChannelMonitor {
                                                                };
                                                                let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
                                                                sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
+                                                               spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
+                                                                       outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
+                                                                       output: single_htlc_tx.output[0].clone(),
+                                                               });
                                                                txn_to_broadcast.push(single_htlc_tx);
                                                        }
                                                }
                                        }
 
-                                       if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
+                                       if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); } // Nothing to be done...probably a false positive/local tx
 
                                        let outputs = vec!(TxOut {
                                                script_pubkey: self.destination_script.clone(),
@@ -1024,25 +1081,29 @@ impl ChannelMonitor {
                                                sign_input!(sighash_parts, input, value.0, value.1.to_vec());
                                        }
 
+                                       spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
+                                               outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
+                                               output: spend_tx.output[0].clone(),
+                                       });
                                        txn_to_broadcast.push(spend_tx);
                                }
                        }
                }
 
-               (txn_to_broadcast, (commitment_txid, watch_outputs))
+               (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs)
        }
 
        /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
-       fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
+       fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> (Option<Transaction>, Option<SpendableOutputDescriptor>) {
                if tx.input.len() != 1 || tx.output.len() != 1 {
-                       return None;
+                       return (None, None)
                }
 
                macro_rules! ignore_error {
                        ( $thing : expr ) => {
                                match $thing {
                                        Ok(a) => a,
-                                       Err(_) => return None
+                                       Err(_) => return (None, None)
                                }
                        };
                }
@@ -1059,7 +1120,7 @@ impl ChannelMonitor {
                        },
                };
                let delayed_key = match self.their_delayed_payment_base_key {
-                       None => return None,
+                       None => return (None, None),
                        Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
                };
                let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
@@ -1112,12 +1173,15 @@ impl ChannelMonitor {
                        spend_tx.input[0].witness.push(vec!(1));
                        spend_tx.input[0].witness.push(redeemscript.into_bytes());
 
-                       Some(spend_tx)
-               } else { None }
+                       let outpoint = BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 };
+                       let output = spend_tx.output[0].clone();
+                       (Some(spend_tx), Some(SpendableOutputDescriptor::StaticOutput { outpoint, output }))
+               } else { (None, None) }
        }
 
-       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
+       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>) {
                let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
+               let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
 
                for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
                        if htlc.offered {
@@ -1133,6 +1197,18 @@ impl ChannelMonitor {
                                htlc_timeout_tx.input[0].witness.push(Vec::new());
                                htlc_timeout_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
 
+                               if let Some(ref per_commitment_point) = *per_commitment_point {
+                                       if let Some(ref delayed_payment_base_key) = *delayed_payment_base_key {
+                                               if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, per_commitment_point, delayed_payment_base_key) {
+                                                       spendable_outputs.push(SpendableOutputDescriptor::DynamicOutput {
+                                                               outpoint: BitcoinOutPoint { txid: htlc_timeout_tx.txid(), vout: 0 },
+                                                               local_delayedkey,
+                                                               witness_script: chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.our_to_self_delay, &local_tx.delayed_payment_key),
+                                                               to_self_delay: self.our_to_self_delay
+                                                       });
+                                               }
+                                       }
+                               }
                                res.push(htlc_timeout_tx);
                        } else {
                                if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1148,34 +1224,61 @@ impl ChannelMonitor {
                                        htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
                                        htlc_success_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
 
+                                       if let Some(ref per_commitment_point) = *per_commitment_point {
+                                               if let Some(ref delayed_payment_base_key) = *delayed_payment_base_key {
+                                                       if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, per_commitment_point, delayed_payment_base_key) {
+                                                               spendable_outputs.push(SpendableOutputDescriptor::DynamicOutput {
+                                                                       outpoint: BitcoinOutPoint { txid: htlc_success_tx.txid(), vout: 0 },
+                                                                       local_delayedkey,
+                                                                       witness_script: chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.our_to_self_delay, &local_tx.delayed_payment_key),
+                                                                       to_self_delay: self.our_to_self_delay
+                                                               });
+                                                       }
+                                               }
+                                       }
                                        res.push(htlc_success_tx);
                                }
                        }
                }
 
-               res
+               (res, spendable_outputs)
        }
 
        /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
        /// revoked using data in local_claimable_outpoints.
        /// Should not be used if check_spend_revoked_transaction succeeds.
-       fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
+       fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>) {
                let commitment_txid = tx.txid();
                if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
                        if local_tx.txid == commitment_txid {
-                               return self.broadcast_by_local_state(local_tx);
+                               match self.key_storage {
+                                       KeyStorage::PrivMode { revocation_base_key: _, htlc_base_key: _, ref delayed_payment_base_key, prev_latest_per_commitment_point: _, ref latest_per_commitment_point } => {
+                                               return self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                       },
+                                       KeyStorage::SigsMode { .. } => {
+                                               return self.broadcast_by_local_state(local_tx, &None, &None);
+                                       }
+                               }
                        }
                }
                if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
                        if local_tx.txid == commitment_txid {
-                               return self.broadcast_by_local_state(local_tx);
+                               match self.key_storage {
+                                       KeyStorage::PrivMode { revocation_base_key: _, htlc_base_key: _, ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
+                                               return self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                       },
+                                       KeyStorage::SigsMode { .. } => {
+                                               return self.broadcast_by_local_state(local_tx, &None, &None);
+                                       }
+                               }
                        }
                }
-               Vec::new()
+               (Vec::new(), Vec::new())
        }
 
-       fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
+       fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>) {
                let mut watch_outputs = Vec::new();
+               let mut spendable_outputs = Vec::new();
                for tx in txn_matched {
                        if tx.input.len() == 1 {
                                // Assuming our keys were not leaked (in which case we're screwed no matter what),
@@ -1185,20 +1288,27 @@ impl ChannelMonitor {
                                let prevout = &tx.input[0].previous_output;
                                let mut txn: Vec<Transaction> = Vec::new();
                                if self.funding_txo.is_none() || (prevout.txid == self.funding_txo.as_ref().unwrap().0.txid && prevout.vout == self.funding_txo.as_ref().unwrap().0.index as u32) {
-                                       let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
+                                       let (remote_txn, new_outputs, mut spendable_output) = self.check_spend_remote_transaction(tx, height);
                                        txn = remote_txn;
+                                       spendable_outputs.append(&mut spendable_output);
                                        if !new_outputs.1.is_empty() {
                                                watch_outputs.push(new_outputs);
                                        }
                                        if txn.is_empty() {
-                                               txn = self.check_spend_local_transaction(tx, height);
+                                               let (remote_txn, mut outputs) = self.check_spend_local_transaction(tx, height);
+                                               spendable_outputs.append(&mut outputs);
+                                               txn = remote_txn;
                                        }
                                } else {
                                        let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
                                        if let Some(commitment_number) = remote_commitment_txn_on_chain.get(&prevout.txid) {
-                                               if let Some(tx) = self.check_spend_remote_htlc(tx, *commitment_number) {
+                                               let (tx, spendable_output) = self.check_spend_remote_htlc(tx, *commitment_number);
+                                               if let Some(tx) = tx {
                                                        txn.push(tx);
                                                }
+                                               if let Some(spendable_output) = spendable_output {
+                                                       spendable_outputs.push(spendable_output);
+                                               }
                                        }
                                }
                                for tx in txn.iter() {
@@ -1209,12 +1319,25 @@ impl ChannelMonitor {
                if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
                        if self.would_broadcast_at_height(height) {
                                broadcaster.broadcast_transaction(&cur_local_tx.tx);
-                               for tx in self.broadcast_by_local_state(&cur_local_tx) {
-                                       broadcaster.broadcast_transaction(&tx);
+                               match self.key_storage {
+                                       KeyStorage::PrivMode { revocation_base_key: _, htlc_base_key: _, ref delayed_payment_base_key, prev_latest_per_commitment_point: _, ref latest_per_commitment_point } => {
+                                               let (txs, mut outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               spendable_outputs.append(&mut outputs);
+                                               for tx in txs {
+                                                       broadcaster.broadcast_transaction(&tx);
+                                               }
+                                       },
+                                       KeyStorage::SigsMode { .. } => {
+                                               let (txs, mut outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
+                                               spendable_outputs.append(&mut outputs);
+                                               for tx in txs {
+                                                       broadcaster.broadcast_transaction(&tx);
+                                               }
+                                       }
                                }
                        }
                }
-               watch_outputs
+               (watch_outputs, spendable_outputs)
        }
 
        pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
@@ -1299,15 +1422,34 @@ impl<R: ::std::io::Read> Readable<R> for ChannelMonitor {
 
                let key_storage = match read_bytes!(1)[0] {
                        0 => {
+                               let revocation_base_key = unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32)));
+                               let htlc_base_key = unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32)));
+                               let delayed_payment_base_key = unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32)));
+                               let prev_latest_per_commitment_point = match read_bytes!(1)[0] {
+                                               0 => None,
+                                               1 => {
+                                                       Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))))
+                                               },
+                                               _ => return Err(DecodeError::InvalidValue),
+                               };
+                               let latest_per_commitment_point = match read_bytes!(1)[0] {
+                                               0 => None,
+                                               1 => {
+                                                       Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))))
+                                               },
+                                               _ => return Err(DecodeError::InvalidValue),
+                               };
                                KeyStorage::PrivMode {
-                                       revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
-                                       htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
+                                       revocation_base_key,
+                                       htlc_base_key,
+                                       delayed_payment_base_key,
+                                       prev_latest_per_commitment_point,
+                                       latest_per_commitment_point,
                                }
                        },
                        _ => return Err(DecodeError::InvalidValue),
                };
 
-               let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
                let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
                let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 
@@ -1470,7 +1612,6 @@ impl<R: ::std::io::Read> Readable<R> for ChannelMonitor {
                        commitment_transaction_number_obscure_factor,
 
                        key_storage,
-                       delayed_payment_base_key,
                        their_htlc_base_key,
                        their_delayed_payment_base_key,
                        their_cur_revocation_points,
@@ -1527,11 +1668,9 @@ mod tests {
                        };
                }
 
-               let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
-
                {
                        // insert_secret correct sequence
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1577,7 +1716,7 @@ mod tests {
 
                {
                        // insert_secret #1 incorrect
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1593,7 +1732,7 @@ mod tests {
 
                {
                        // insert_secret #2 incorrect (#1 derived from incorrect)
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1619,7 +1758,7 @@ mod tests {
 
                {
                        // insert_secret #3 incorrect
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1645,7 +1784,7 @@ mod tests {
 
                {
                        // insert_secret #4 incorrect (1,2,3 derived from incorrect)
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1691,7 +1830,7 @@ mod tests {
 
                {
                        // insert_secret #5 incorrect
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1727,7 +1866,7 @@ mod tests {
 
                {
                        // insert_secret #6 incorrect (5 derived from incorrect)
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1773,7 +1912,7 @@ mod tests {
 
                {
                        // insert_secret #7 incorrect
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1819,7 +1958,7 @@ mod tests {
 
                {
                        // insert_secret #8 incorrect
-                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+                       monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                        secrets.clear();
 
                        secrets.push([0; 32]);
@@ -1937,8 +2076,7 @@ mod tests {
 
                // Prune with one old state and a local commitment tx holding a few overlaps with the
                // old state.
-               let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
-               let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
+               let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), 0, Script::new());
                monitor.set_their_to_self_delay(10);
 
                monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
index 94cdef9e41fe76f7fa568edba784961edaeb8825..82784efe5fc037c97cb28da923b7f00e235e993e 100644 (file)
@@ -796,6 +796,7 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                        Event::PaymentSent {..} => { /* Hand upstream */ },
                                        Event::PaymentFailed {..} => { /* Hand upstream */ },
                                        Event::PendingHTLCsForwardable {..} => { /* Hand upstream */ },
+                                       Event::SpendableOutputs { .. } => { /* Hand upstream */ },
 
                                        Event::SendOpenChannel { ref node_id, ref msg } => {
                                                log_trace!(self, "Handling SendOpenChannel event in peer_handler for node {} for channel {}",
index ccfe0f8ac1527795aa157c5d6163f54c506110be..3a077a4b5ba9caad01086b23bad35a404217a57f 100644 (file)
@@ -14,6 +14,7 @@
 
 use ln::msgs;
 use chain::transaction::OutPoint;
+use chain::keysinterface::SpendableOutputDescriptor;
 
 use bitcoin::blockdata::script::Script;
 
@@ -89,6 +90,13 @@ pub enum Event {
                /// The earliest time at which process_pending_htlc_forwards should be called.
                time_forwardable: Instant,
        },
+       /// Used to indicate that an output was generated on-chain which you should know how to spend.
+       /// Such an output will *not* ever be spent by rust-lightning, so you need to store them
+       /// somewhere and spend them when you create on-chain spends.
+       SpendableOutputs {
+               /// The outputs which you should store as spendable by you.
+               outputs: Vec<SpendableOutputDescriptor>,
+       },
 
        // Events indicating the network loop should send a message to a peer:
        // TODO: Move these into a separate struct and make a top-level enum