X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fln%2Fchannelmonitor.rs;h=15db1426735b66643dde33477a43502be4ead2a1;hb=bca12ea48e0f7be2f28dd96b5fbdda89c8cbde53;hp=cee406d000ef41f763d6853df4b70bce9396948c;hpb=dfbc6c60a73ee0f57fb899d414d2f385b5ab1308;p=rust-lightning diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index cee406d0..15db1426 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -17,35 +17,39 @@ use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint; use bitcoin::blockdata::script::{Script, Builder}; use bitcoin::blockdata::opcodes; use bitcoin::consensus::encode::{self, Decodable, Encodable}; -use bitcoin::util::hash::{Hash160, BitcoinHash,Sha256dHash}; +use bitcoin::util::hash::BitcoinHash; use bitcoin::util::bip143; -use crypto::digest::Digest; +use bitcoin_hashes::Hash; +use bitcoin_hashes::sha256::Hash as Sha256; +use bitcoin_hashes::hash160::Hash as Hash160; +use bitcoin_hashes::sha256d::Hash as Sha256dHash; -use secp256k1::{Secp256k1,Message,Signature}; +use secp256k1::{Secp256k1,Signature}; use secp256k1::key::{SecretKey,PublicKey}; use secp256k1; use ln::msgs::DecodeError; use ln::chan_utils; use ln::chan_utils::HTLCOutputInCommitment; -use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface}; +use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash}; +use ln::channel::{ACCEPTED_HTLC_SCRIPT_WEIGHT, OFFERED_HTLC_SCRIPT_WEIGHT}; +use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator, ConfirmationTarget}; use chain::transaction::OutPoint; use chain::keysinterface::SpendableOutputDescriptor; use util::logger::Logger; use util::ser::{ReadableArgs, Readable, Writer, Writeable, WriterWriteAdaptor, U48}; -use util::sha2::Sha256; use util::{byte_utils, events}; -use std::collections::HashMap; +use std::collections::{HashMap, hash_map}; use std::sync::{Arc,Mutex}; use std::{hash,cmp, mem}; /// An error enum representing a failure to persist a channel monitor update. #[derive(Clone)] pub enum ChannelMonitorUpdateErr { - /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected - /// to succeed at some point in the future). + /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of + /// our state failed, but is expected to succeed at some point in the future). /// /// Such a failure will "freeze" a channel, preventing us from revoking old states or /// submitting new commitment transactions to the remote party. @@ -67,10 +71,16 @@ pub enum ChannelMonitorUpdateErr { /// Note that even if updates made after TemporaryFailure succeed you must still call /// test_restore_channel_monitor to ensure you have the latest monitor and re-enable normal /// channel operation. + /// + /// For deployments where a copy of ChannelMonitors and other local state are backed up in a + /// remote location (with local copies persisted immediately), it is anticipated that all + /// updates will return TemporaryFailure until the remote copies could be updated. TemporaryFailure, /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a /// different watchtower and cannot update with all watchtowers that were previously informed /// of this channel). This will force-close the channel in question. + /// + /// Should also be used to indicate a failure to update the local copy of the channel monitor. PermanentFailure, } @@ -82,6 +92,14 @@ pub enum ChannelMonitorUpdateErr { #[derive(Debug)] pub struct MonitorUpdateError(pub &'static str); +/// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a +/// forward channel and from which info are needed to update HTLC in a backward channel. +pub struct HTLCUpdate { + pub(super) payment_hash: PaymentHash, + pub(super) payment_preimage: Option, + pub(super) source: HTLCSource +} + /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing /// events to it, while also taking any add_update_monitor events and passing them to some remote @@ -98,6 +116,10 @@ pub trait ManyChannelMonitor: Send + Sync { /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with /// any spends of it. fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>; + + /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated + /// with success or failure backward + fn fetch_pending_htlc_updated(&self) -> Vec; } /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a @@ -119,27 +141,64 @@ pub struct SimpleManyChannelMonitor { chain_monitor: Arc, broadcaster: Arc, pending_events: Mutex>, + pending_htlc_updated: Mutex)>>>, logger: Arc, + fee_estimator: Arc } impl ChainListener for SimpleManyChannelMonitor { fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) { let block_hash = header.bitcoin_hash(); let mut new_events: Vec = Vec::with_capacity(0); + let mut htlc_updated_infos = Vec::new(); { let mut monitors = self.monitors.lock().unwrap(); for monitor in monitors.values_mut() { - let (txn_outputs, spendable_outputs) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster); + let (txn_outputs, spendable_outputs, mut htlc_updated) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator); if spendable_outputs.len() > 0 { new_events.push(events::Event::SpendableOutputs { outputs: spendable_outputs, }); } + 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); } } + htlc_updated_infos.append(&mut htlc_updated); + } + } + { + // ChannelManager will just need to fetch pending_htlc_updated and pass state backward + let mut pending_htlc_updated = self.pending_htlc_updated.lock().unwrap(); + for htlc in htlc_updated_infos.drain(..) { + match pending_htlc_updated.entry(htlc.2) { + hash_map::Entry::Occupied(mut e) => { + // In case of reorg we may have htlc outputs solved in a different way so + // we prefer to keep claims but don't store duplicate updates for a given + // (payment_hash, HTLCSource) pair. + // TODO: Note that we currently don't really use this as ChannelManager + // will fail/claim backwards after the first block. We really should delay + // a few blocks before failing backwards (but can claim backwards + // immediately) as long as we have a few blocks of headroom. + let mut existing_claim = false; + e.get_mut().retain(|htlc_data| { + if htlc.0 == htlc_data.0 { + if htlc_data.1.is_some() { + existing_claim = true; + true + } else { false } + } else { true } + }); + if !existing_claim { + e.get_mut().push((htlc.0, htlc.1)); + } + } + hash_map::Entry::Vacant(e) => { + e.insert(vec![(htlc.0, htlc.1)]); + } + } } } let mut pending_events = self.pending_events.lock().unwrap(); @@ -152,39 +211,47 @@ impl ChainListener for SimpleManyChannelMonit impl SimpleManyChannelMonitor { /// Creates a new object which can be used to monitor several channels given the chain /// interface with which to register to receive notifications. - pub fn new(chain_monitor: Arc, broadcaster: Arc, logger: Arc) -> Arc> { + pub fn new(chain_monitor: Arc, broadcaster: Arc, logger: Arc, feeest: Arc) -> Arc> { let res = Arc::new(SimpleManyChannelMonitor { monitors: Mutex::new(HashMap::new()), chain_monitor, broadcaster, pending_events: Mutex::new(Vec::new()), + pending_htlc_updated: Mutex::new(HashMap::new()), logger, + fee_estimator: feeest, }); let weak_res = Arc::downgrade(&res); res.chain_monitor.register_listener(weak_res); res } - /// Adds or udpates the monitor which monitors the channel referred to by the given key. + /// Adds or updates the monitor which monitors the channel referred to by the given key. pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), MonitorUpdateError> { let mut monitors = self.monitors.lock().unwrap(); match monitors.get_mut(&key) { Some(orig_monitor) => { - log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_option!(monitor.funding_txo)); + log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(monitor.key_storage)); return orig_monitor.insert_combine(monitor); }, None => {} }; - match &monitor.funding_txo { - &None => { - log_trace!(self, "Got new Channel Monitor for no-funding-set channel (monitoring all txn!)"); - self.chain_monitor.watch_all_txn() - }, - &Some((ref outpoint, ref script)) => { - log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..])); - self.chain_monitor.install_watch_tx(&outpoint.txid, script); - self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script); + match monitor.key_storage { + Storage::Local { ref funding_info, .. } => { + match funding_info { + &None => { + return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !")); + }, + &Some((ref outpoint, ref script)) => { + log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..])); + self.chain_monitor.install_watch_tx(&outpoint.txid, script); + self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script); + }, + } }, + Storage::Watchtower { .. } => { + self.chain_monitor.watch_all_txn(); + } } monitors.insert(key, monitor); Ok(()) @@ -198,6 +265,21 @@ impl ManyChannelMonitor for SimpleManyChannelMonitor { Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure), } } + + fn fetch_pending_htlc_updated(&self) -> Vec { + let mut updated = self.pending_htlc_updated.lock().unwrap(); + let mut pending_htlcs_updated = Vec::with_capacity(updated.len()); + for (k, v) in updated.drain() { + for htlc_data in v { + pending_htlcs_updated.push(HTLCUpdate { + payment_hash: k, + payment_preimage: htlc_data.1, + source: htlc_data.0, + }); + } + } + pending_htlcs_updated + } } impl events::EventsProvider for SimpleManyChannelMonitor { @@ -221,10 +303,15 @@ pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6; /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our /// copies of ChannelMonitors, including watchtowers). pub(crate) const HTLC_FAIL_TIMEOUT_BLOCKS: u32 = 3; +/// Number of blocks we wait on seeing a confirmed HTLC-Timeout or previous revoked commitment +/// transaction before we fail corresponding inbound HTLCs. This prevents us from failing backwards +/// and then getting a reorg resulting in us losing money. +//TODO: We currently don't actually use this...we should +pub(crate) const HTLC_FAIL_ANTI_REORG_DELAY: u32 = 6; #[derive(Clone, PartialEq)] -enum KeyStorage { - PrivMode { +enum Storage { + Local { revocation_base_key: SecretKey, htlc_base_key: SecretKey, delayed_payment_base_key: SecretKey, @@ -232,11 +319,13 @@ enum KeyStorage { shutdown_pubkey: PublicKey, prev_latest_per_commitment_point: Option, latest_per_commitment_point: Option, + funding_info: Option<(OutPoint, Script)>, + current_remote_commitment_txid: Option, + prev_remote_commitment_txid: Option, }, - SigsMode { + Watchtower { revocation_base_key: PublicKey, htlc_base_key: PublicKey, - sigs: HashMap, } } @@ -250,7 +339,16 @@ struct LocalSignedTx { b_htlc_key: PublicKey, delayed_payment_key: PublicKey, feerate_per_kw: u64, - htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>, + htlc_outputs: Vec<(HTLCOutputInCommitment, Option<(Signature, Signature)>, Option)>, +} + +#[derive(PartialEq)] +enum InputDescriptors { + RevokedOfferedHTLC, + RevokedReceivedHTLC, + OfferedHTLC, + ReceivedHTLC, + RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output } const SERIALIZATION_VERSION: u8 = 1; @@ -263,10 +361,9 @@ const MIN_SERIALIZATION_VERSION: u8 = 1; /// information and are actively monitoring the chain. #[derive(Clone)] pub struct ChannelMonitor { - funding_txo: Option<(OutPoint, Script)>, commitment_transaction_number_obscure_factor: u64, - key_storage: KeyStorage, + key_storage: Storage, their_htlc_base_key: Option, their_delayed_payment_base_key: Option, // first is the idx of the first of the two revocation points @@ -276,7 +373,7 @@ pub struct ChannelMonitor { their_to_self_delay: Option, old_secrets: [([u8; 32], u64); 49], - remote_claimable_outpoints: HashMap>, + remote_claimable_outpoints: HashMap>)>>, /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain. /// Nor can we figure out their commitment numbers without the commitment transaction they are /// spending. Thus, in order to claim them via revocation key, we track all the remote @@ -287,7 +384,7 @@ pub struct ChannelMonitor { /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked /// remote transactions (ie should remain pretty small). /// Serialized to disk but should generally not be sent to Watchtowers. - remote_hash_commitment_number: HashMap<[u8; 32], u64>, + remote_hash_commitment_number: HashMap, // We store two local commitment transactions to avoid any race conditions where we may update // some monitors (potentially on watchtowers) but then fail to update others, resulting in the @@ -300,7 +397,7 @@ pub struct ChannelMonitor { // deserialization current_remote_commitment_number: u64, - payment_preimages: HashMap<[u8; 32], [u8; 32]>, + payment_preimages: HashMap, destination_script: Script, @@ -319,8 +416,7 @@ pub struct ChannelMonitor { /// underlying object impl PartialEq for ChannelMonitor { fn eq(&self, other: &Self) -> bool { - if self.funding_txo != other.funding_txo || - self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor || + if self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor || self.key_storage != other.key_storage || self.their_htlc_base_key != other.their_htlc_base_key || self.their_delayed_payment_base_key != other.their_delayed_payment_base_key || @@ -351,10 +447,9 @@ impl PartialEq for ChannelMonitor { impl ChannelMonitor { pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, payment_base_key: &SecretKey, shutdown_pubkey: &PublicKey, our_to_self_delay: u16, destination_script: Script, logger: Arc) -> ChannelMonitor { ChannelMonitor { - funding_txo: None, commitment_transaction_number_obscure_factor: 0, - key_storage: KeyStorage::PrivMode { + key_storage: Storage::Local { revocation_base_key: revocation_base_key.clone(), htlc_base_key: htlc_base_key.clone(), delayed_payment_base_key: delayed_payment_base_key.clone(), @@ -362,6 +457,9 @@ impl ChannelMonitor { shutdown_pubkey: shutdown_pubkey.clone(), prev_latest_per_commitment_point: None, latest_per_commitment_point: None, + funding_info: None, + current_remote_commitment_txid: None, + prev_remote_commitment_txid: None, }, their_htlc_base_key: None, their_delayed_payment_base_key: None, @@ -388,6 +486,36 @@ impl ChannelMonitor { } } + fn get_witnesses_weight(inputs: &[InputDescriptors]) -> u64 { + let mut tx_weight = 2; // count segwit flags + for inp in inputs { + // We use expected weight (and not actual) as signatures and time lock delays may vary + tx_weight += match inp { + // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script + &InputDescriptors::RevokedOfferedHTLC => { + 1 + 1 + 73 + 1 + 33 + 1 + 133 + }, + // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script + &InputDescriptors::RevokedReceivedHTLC => { + 1 + 1 + 73 + 1 + 33 + 1 + 139 + }, + // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script + &InputDescriptors::OfferedHTLC => { + 1 + 1 + 73 + 1 + 32 + 1 + 133 + }, + // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script + &InputDescriptors::ReceivedHTLC => { + 1 + 1 + 73 + 1 + 1 + 1 + 139 + }, + // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script + &InputDescriptors::RevokedOutput => { + 1 + 1 + 73 + 1 + 1 + 1 + 77 + }, + }; + } + tx_weight + } + #[inline] fn place_secret(idx: u64) -> u8 { for i in 0..48 { @@ -405,9 +533,7 @@ impl ChannelMonitor { let bitpos = bits - 1 - i; if idx & (1 << bitpos) == (1 << bitpos) { res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7); - let mut sha = Sha256::new(); - sha.input(&res); - sha.result(&mut res); + res = Sha256::hash(&res).into_inner(); } } res @@ -424,8 +550,22 @@ impl ChannelMonitor { return Err(MonitorUpdateError("Previous secret did not match new one")); } } + if self.get_min_seen_secret() <= idx { + return Ok(()); + } self.old_secrets[pos as usize] = (secret, idx); + // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill + // events for now-revoked/fulfilled HTLCs. + // TODO: We should probably consider whether we're really getting the next secret here. + if let Storage::Local { ref mut prev_remote_commitment_txid, .. } = self.key_storage { + if let Some(txid) = prev_remote_commitment_txid.take() { + for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() { + *source = None; + } + } + } + if !self.payment_preimages.is_empty() { let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !"); let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref(); @@ -465,15 +605,23 @@ impl ChannelMonitor { /// The monitor watches for it to be broadcasted and then uses the HTLC information (and /// possibly future revocation/preimage information) to claim outputs where possible. /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers. - pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec, commitment_number: u64, their_revocation_point: PublicKey) { + pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option>)>, commitment_number: u64, their_revocation_point: PublicKey) { // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction // so that a remote monitor doesn't learn anything unless there is a malicious close. // (only maybe, sadly we cant do the same for local info, as we need to be aware of // timeouts) - for htlc in &htlc_outputs { + for &(ref htlc, _) in &htlc_outputs { self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number); } - self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs); + + let new_txid = unsigned_commitment_tx.txid(); + log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len()); + log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx)); + if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage { + *prev_remote_commitment_txid = current_remote_commitment_txid.take(); + *current_remote_commitment_txid = Some(new_txid); + } + self.remote_claimable_outpoints.insert(new_txid, htlc_outputs); self.current_remote_commitment_number = commitment_number; //TODO: Merge this into the other per-remote-transaction output storage stuff match self.their_cur_revocation_points { @@ -501,9 +649,9 @@ 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 + /// Also update Storage 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)>) { + 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, Option<(Signature, Signature)>, Option)>) { assert!(self.their_to_self_delay.is_some()); self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take(); self.current_local_signed_commitment_tx = Some(LocalSignedTx { @@ -516,22 +664,17 @@ 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, ref payment_base_key, ref shutdown_pubkey, 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, - payment_base_key: *payment_base_key, - shutdown_pubkey: *shutdown_pubkey, - prev_latest_per_commitment_point: *latest_per_commitment_point, - latest_per_commitment_point: Some(local_keys.per_commitment_point), - } - } else { unimplemented!(); }; + + if let Storage::Local { ref mut latest_per_commitment_point, .. } = self.key_storage { + *latest_per_commitment_point = Some(local_keys.per_commitment_point); + } else { + panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?"); + } } /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all /// commitment_tx_infos which contain the payment hash have been revoked. - pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) { + pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) { self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone()); } @@ -539,14 +682,28 @@ impl ChannelMonitor { /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the /// chain for new blocks/transactions. pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), MonitorUpdateError> { - if self.funding_txo.is_some() { - // We should be able to compare the entire funding_txo, but in fuzztarget its trivially - // easy to collide the funding_txo hash and have a different scriptPubKey. - if other.funding_txo.is_some() && other.funding_txo.as_ref().unwrap().0 != self.funding_txo.as_ref().unwrap().0 { - return Err(MonitorUpdateError("Funding transaction outputs are not identical!")); - } - } else { - self.funding_txo = other.funding_txo.take(); + match self.key_storage { + Storage::Local { ref funding_info, .. } => { + if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); } + let our_funding_info = funding_info; + if let Storage::Local { ref funding_info, .. } = other.key_storage { + if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); } + // We should be able to compare the entire funding_txo, but in fuzztarget it's trivially + // easy to collide the funding_txo hash and have a different scriptPubKey. + if funding_info.as_ref().unwrap().0 != our_funding_info.as_ref().unwrap().0 { + return Err(MonitorUpdateError("Funding transaction outputs are not identical!")); + } + } else { + return Err(MonitorUpdateError("Try to combine a Local monitor with a Watchtower one !")); + } + }, + Storage::Watchtower { .. } => { + if let Storage::Watchtower { .. } = other.key_storage { + unimplemented!(); + } else { + return Err(MonitorUpdateError("Try to combine a Watchtower monitor with a Local one !")); + } + }, } let other_min_secret = other.get_min_seen_secret(); let our_min_secret = self.get_min_seen_secret(); @@ -594,8 +751,15 @@ impl ChannelMonitor { /// provides slightly better privacy. /// It's the responsibility of the caller to register outpoint and script with passing the former /// value as key to add_update_monitor. - pub(super) fn set_funding_info(&mut self, funding_info: (OutPoint, Script)) { - self.funding_txo = Some(funding_info); + pub(super) fn set_funding_info(&mut self, new_funding_info: (OutPoint, Script)) { + match self.key_storage { + Storage::Local { ref mut funding_info, .. } => { + *funding_info = Some(new_funding_info); + }, + Storage::Watchtower { .. } => { + panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?"); + } + } } /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx @@ -609,14 +773,28 @@ impl ChannelMonitor { } pub(super) fn unset_funding_info(&mut self) { - self.funding_txo = None; + match self.key_storage { + Storage::Local { ref mut funding_info, .. } => { + *funding_info = None; + }, + Storage::Watchtower { .. } => { + panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?"); + }, + } } /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for. pub fn get_funding_txo(&self) -> Option { - match self.funding_txo { - Some((outpoint, _)) => Some(outpoint), - None => None + match self.key_storage { + Storage::Local { ref funding_info, .. } => { + match funding_info { + &Some((outpoint, _)) => Some(outpoint), + &None => None + } + }, + Storage::Watchtower { .. } => { + return None; + } } } @@ -641,24 +819,23 @@ impl ChannelMonitor { writer.write_all(&[SERIALIZATION_VERSION; 1])?; writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?; - match &self.funding_txo { - &Some((ref outpoint, ref script)) => { - writer.write_all(&outpoint.txid[..])?; - writer.write_all(&byte_utils::be16_to_array(outpoint.index))?; - script.write(writer)?; - }, - &None => { - // We haven't even been initialized...not sure why anyone is serializing us, but - // not much to give them. - return Ok(()); - }, - } - // Set in initial Channel-object creation, so should always be set by now: U48(self.commitment_transaction_number_obscure_factor).write(writer)?; + macro_rules! write_option { + ($thing: expr) => { + match $thing { + &Some(ref t) => { + 1u8.write(writer)?; + t.write(writer)?; + }, + &None => 0u8.write(writer)?, + } + } + } + match self.key_storage { - KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point } => { + Storage::Local { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point, ref funding_info, ref current_remote_commitment_txid, ref prev_remote_commitment_txid } => { writer.write_all(&[0; 1])?; writer.write_all(&revocation_base_key[..])?; writer.write_all(&htlc_base_key[..])?; @@ -677,9 +854,20 @@ impl ChannelMonitor { } else { writer.write_all(&[0; 1])?; } - + match funding_info { + &Some((ref outpoint, ref script)) => { + writer.write_all(&outpoint.txid[..])?; + writer.write_all(&byte_utils::be16_to_array(outpoint.index))?; + script.write(writer)?; + }, + &None => { + debug_assert!(false, "Try to serialize a useless Local monitor !"); + }, + } + write_option!(current_remote_commitment_txid); + write_option!(prev_remote_commitment_txid); }, - KeyStorage::SigsMode { .. } => unimplemented!(), + Storage::Watchtower { .. } => unimplemented!(), } writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?; @@ -716,17 +904,18 @@ impl ChannelMonitor { writer.write_all(&[$htlc_output.offered as u8; 1])?; writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?; writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?; - writer.write_all(&$htlc_output.payment_hash)?; - writer.write_all(&byte_utils::be32_to_array($htlc_output.transaction_output_index))?; + writer.write_all(&$htlc_output.payment_hash.0[..])?; + write_option!(&$htlc_output.transaction_output_index); } } writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?; - for (ref txid, ref htlc_outputs) in self.remote_claimable_outpoints.iter() { + for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() { writer.write_all(&txid[..])?; - writer.write_all(&byte_utils::be64_to_array(htlc_outputs.len() as u64))?; - for htlc_output in htlc_outputs.iter() { + writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?; + for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() { serialize_htlc_in_commitment!(htlc_output); + write_option!(htlc_source); } } @@ -743,7 +932,7 @@ impl ChannelMonitor { if for_local_storage { writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?; for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() { - writer.write_all(*payment_hash)?; + writer.write_all(&payment_hash.0[..])?; writer.write_all(&byte_utils::be48_to_array(*commitment_number))?; } } else { @@ -766,10 +955,16 @@ impl ChannelMonitor { writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?; writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?; - for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() { + for &(ref htlc_output, ref sigs, ref htlc_source) in $local_tx.htlc_outputs.iter() { serialize_htlc_in_commitment!(htlc_output); - writer.write_all(&their_sig.serialize_compact(&self.secp_ctx))?; - writer.write_all(&our_sig.serialize_compact(&self.secp_ctx))?; + if let &Some((ref their_sig, ref our_sig)) = sigs { + 1u8.write(writer)?; + writer.write_all(&their_sig.serialize_compact())?; + writer.write_all(&our_sig.serialize_compact())?; + } else { + 0u8.write(writer)?; + } + write_option!(htlc_source); } } } @@ -796,7 +991,7 @@ impl ChannelMonitor { writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?; for payment_preimage in self.payment_preimages.values() { - writer.write_all(payment_preimage)?; + writer.write_all(&payment_preimage.0[..])?; } self.last_block_hash.write(writer)?; @@ -827,9 +1022,6 @@ impl ChannelMonitor { self.write(writer, false) } - //TODO: Functions to serialize/deserialize (with different forms depending on which information - //we want to leave out (eg funding_txo, etc). - /// Can only fail if idx is < get_min_seen_secret pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> { for i in 0..self.old_secrets.len() { @@ -866,12 +1058,15 @@ 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(&mut self, tx: &Transaction, height: u32) -> (Vec, (Sha256dHash, Vec), Vec) { + /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of + /// revoked remote commitment tx + fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32, fee_estimator: &FeeEstimator) -> (Vec, (Sha256dHash, Vec), Vec, Vec<(HTLCSource, Option, PaymentHash)>) { // 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 mut htlc_updated = 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); @@ -880,7 +1075,7 @@ impl ChannelMonitor { ( $thing : expr ) => { match $thing { Ok(a) => a, - Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs) + Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated) } }; } @@ -888,15 +1083,15 @@ impl ChannelMonitor { let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor); if commitment_number >= self.get_min_seen_secret() { let secret = self.get_secret(commitment_number).unwrap(); - let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret)); + let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret)); let (revocation_pubkey, b_htlc_key, local_payment_key) = match self.key_storage { - KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key, ref payment_base_key, .. } => { + Storage::Local { ref revocation_base_key, ref htlc_base_key, ref payment_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))), Some(ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &payment_base_key)))) }, - KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => { + Storage::Watchtower { 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, &revocation_base_key)), ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)), @@ -905,7 +1100,7 @@ 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), spendable_outputs), + None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated), 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)), }; @@ -915,14 +1110,15 @@ impl ChannelMonitor { let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key { // Note that the Network here is ignored as we immediately drop the address for the // script_pubkey version. - let payment_hash160 = Hash160::from_data(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize()); - Some(Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()) + let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize()); + Some(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()) } else { None }; let mut total_value = 0; let mut values = Vec::new(); let mut inputs = Vec::new(); let mut htlc_idxs = Vec::new(); + let mut input_descriptors = Vec::new(); for (idx, outp) in tx.output.iter().enumerate() { if outp.script_pubkey == revokeable_p2wsh { @@ -938,6 +1134,7 @@ impl ChannelMonitor { htlc_idxs.push(None); values.push(outp.value); total_value += outp.value; + input_descriptors.push(InputDescriptors::RevokedOutput); } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() { spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH { outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, @@ -951,20 +1148,20 @@ impl ChannelMonitor { ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => { { let (sig, redeemscript) = match self.key_storage { - KeyStorage::PrivMode { ref revocation_base_key, .. } => { + Storage::Local { ref revocation_base_key, .. } => { let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else { - let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()]; + let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()].0; chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey) }; - let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..])); + let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]); let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key)); (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript) }, - KeyStorage::SigsMode { .. } => { + Storage::Watchtower { .. } => { unimplemented!(); } }; - $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec()); + $input.witness.push(sig.serialize_der().to_vec()); $input.witness[0].push(SigHashType::All as u8); if $htlc_idx.is_none() { $input.witness.push(vec!(1)); @@ -976,57 +1173,87 @@ impl ChannelMonitor { } } - if let Some(per_commitment_data) = per_commitment_option { + if let Some(ref per_commitment_data) = per_commitment_option { inputs.reserve_exact(per_commitment_data.len()); - for (idx, htlc) in per_commitment_data.iter().enumerate() { - let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey); - 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), spendable_outputs); // Corrupted per_commitment_data, fuck this user - } - let input = TxIn { - previous_output: BitcoinOutPoint { - txid: commitment_txid, - vout: htlc.transaction_output_index, - }, - script_sig: Script::new(), - sequence: 0xfffffffd, - witness: Vec::new(), - }; - if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER { - inputs.push(input); - htlc_idxs.push(Some(idx)); - values.push(tx.output[htlc.transaction_output_index as usize].value); - total_value += htlc.amount_msat / 1000; - } else { - let mut single_htlc_tx = Transaction { - version: 2, - lock_time: 0, - input: vec![input], - output: vec!(TxOut { - script_pubkey: self.destination_script.clone(), - value: htlc.amount_msat / 1000, //TODO: - fee - }), + for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() { + if let Some(transaction_output_index) = htlc.transaction_output_index { + let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey); + if transaction_output_index as usize >= tx.output.len() || + tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 || + tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() { + return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user + } + let input = TxIn { + previous_output: BitcoinOutPoint { + txid: commitment_txid, + vout: transaction_output_index, + }, + script_sig: Script::new(), + sequence: 0xfffffffd, + witness: Vec::new(), }; - let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx); - sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000); - txn_to_broadcast.push(single_htlc_tx); + if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER { + inputs.push(input); + htlc_idxs.push(Some(idx)); + values.push(tx.output[transaction_output_index as usize].value); + total_value += htlc.amount_msat / 1000; + input_descriptors.push(if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }); + } else { + let mut single_htlc_tx = Transaction { + version: 2, + lock_time: 0, + input: vec![input], + output: vec!(TxOut { + script_pubkey: self.destination_script.clone(), + value: htlc.amount_msat / 1000, + }), + }; + single_htlc_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }])) / 1000; + let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx); + sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000); + txn_to_broadcast.push(single_htlc_tx); + } } } } - if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours + if !inputs.is_empty() || !txn_to_broadcast.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours // We're definitely a remote commitment transaction! + log_trace!(self, "Got broadcast of revoked remote commitment transaction, generating general spend tx with {} inputs and {} other txn to broadcast", inputs.len(), txn_to_broadcast.len()); watch_outputs.append(&mut tx.output.clone()); self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect())); + + // TODO: We really should only fail backwards after our revocation claims have been + // confirmed, but we also need to do more other tracking of in-flight pre-confirm + // on-chain claims, so we can do that at the same time. + macro_rules! check_htlc_fails { + ($txid: expr, $commitment_tx: expr) => { + if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) { + for &(ref htlc, ref source_option) in outpoints.iter() { + if let &Some(ref source) = source_option { + log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx); + htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone())); + } + } + } + } + } + if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage { + if let &Some(ref txid) = current_remote_commitment_txid { + check_htlc_fails!(txid, "current"); + } + if let &Some(ref txid) = prev_remote_commitment_txid { + check_htlc_fails!(txid, "remote"); + } + } + // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment 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 + if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx let outputs = vec!(TxOut { script_pubkey: self.destination_script.clone(), - value: total_value, //TODO: - fee + value: total_value, }); let mut spend_tx = Transaction { version: 2, @@ -1034,6 +1261,7 @@ impl ChannelMonitor { input: inputs, output: outputs, }; + spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..])) / 1000; let mut values_drain = values.drain(..); let sighash_parts = bip143::SighashComponents::new(&spend_tx); @@ -1059,6 +1287,46 @@ impl ChannelMonitor { watch_outputs.append(&mut tx.output.clone()); self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect())); + log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid); + + // TODO: We really should only fail backwards after our revocation claims have been + // confirmed, but we also need to do more other tracking of in-flight pre-confirm + // on-chain claims, so we can do that at the same time. + macro_rules! check_htlc_fails { + ($txid: expr, $commitment_tx: expr, $id: tt) => { + if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) { + $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() { + if let &Some(ref source) = source_option { + // Check if the HTLC is present in the commitment transaction that was + // broadcast, but not if it was below the dust limit, which we should + // fail backwards immediately as there is no way for us to learn the + // payment_preimage. + // Note that if the dust limit were allowed to change between + // commitment transactions we'd want to be check whether *any* + // broadcastable commitment transaction has the HTLC in it, but it + // cannot currently change after channel initialization, so we don't + // need to here. + for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() { + if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() { + continue $id; + } + } + log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx); + htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone())); + } + } + } + } + } + if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage { + if let &Some(ref txid) = current_remote_commitment_txid { + check_htlc_fails!(txid, "current", 'current_loop); + } + if let &Some(ref txid) = prev_remote_commitment_txid { + check_htlc_fails!(txid, "previous", 'prev_loop); + } + } + if let Some(revocation_points) = self.their_cur_revocation_points { let revocation_point_option = if revocation_points.0 == commitment_number { Some(&revocation_points.1) } @@ -1067,24 +1335,24 @@ 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, .. } => { + Storage::Local { 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)))) }, - KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => { + Storage::Watchtower { ref revocation_base_key, ref htlc_base_key, .. } => { (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)), ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key))) }, }; let a_htlc_key = match self.their_htlc_base_key { - None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs), + None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated), Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)), }; for (idx, outp) in tx.output.iter().enumerate() { if outp.script_pubkey.is_v0_p2wpkh() { match self.key_storage { - KeyStorage::PrivMode { ref payment_base_key, .. } => { + Storage::Local { ref payment_base_key, .. } => { if let Ok(local_key) = chan_utils::derive_private_key(&self.secp_ctx, &revocation_point, &payment_base_key) { spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH { outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, @@ -1093,7 +1361,7 @@ impl ChannelMonitor { }); } }, - KeyStorage::SigsMode { .. } => {} + Storage::Watchtower { .. } => {} } break; // Only to_remote ouput is claimable } @@ -1102,23 +1370,24 @@ impl ChannelMonitor { let mut total_value = 0; let mut values = Vec::new(); let mut inputs = Vec::new(); + let mut input_descriptors = Vec::new(); macro_rules! sign_input { ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => { { let (sig, redeemscript) = match self.key_storage { - KeyStorage::PrivMode { ref htlc_base_key, .. } => { - let htlc = &per_commitment_option.unwrap()[$input.sequence as usize]; + Storage::Local { ref htlc_base_key, .. } => { + let htlc = &per_commitment_option.unwrap()[$input.sequence as usize].0; let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey); - let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..])); + let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]); let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key)); (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript) }, - KeyStorage::SigsMode { .. } => { + Storage::Watchtower { .. } => { unimplemented!(); } }; - $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec()); + $input.witness.push(sig.serialize_der().to_vec()); $input.witness[0].push(SigHashType::All as u8); $input.witness.push($preimage); $input.witness.push(redeemscript.into_bytes()); @@ -1126,47 +1395,82 @@ impl ChannelMonitor { } } - for (idx, htlc) in per_commitment_data.iter().enumerate() { - if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) { - let input = TxIn { - previous_output: BitcoinOutPoint { - txid: commitment_txid, - vout: htlc.transaction_output_index, - }, - script_sig: Script::new(), - sequence: idx as u32, // reset to 0xfffffffd in sign_input - witness: Vec::new(), - }; - if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER { - inputs.push(input); - values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage)); - total_value += htlc.amount_msat / 1000; - } else { - let mut single_htlc_tx = Transaction { + for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() { + if let Some(transaction_output_index) = htlc.transaction_output_index { + let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey); + if transaction_output_index as usize >= tx.output.len() || + tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 || + tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() { + return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user + } + if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) { + let input = TxIn { + previous_output: BitcoinOutPoint { + txid: commitment_txid, + vout: transaction_output_index, + }, + script_sig: Script::new(), + sequence: idx as u32, // reset to 0xfffffffd in sign_input + witness: Vec::new(), + }; + if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER { + inputs.push(input); + values.push((tx.output[transaction_output_index as usize].value, payment_preimage)); + total_value += htlc.amount_msat / 1000; + input_descriptors.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }); + } else { + let mut single_htlc_tx = Transaction { + version: 2, + lock_time: 0, + input: vec![input], + output: vec!(TxOut { + script_pubkey: self.destination_script.clone(), + value: htlc.amount_msat / 1000, + }), + }; + single_htlc_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }])) / 1000; + let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx); + sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.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 !htlc.offered { + // TODO: If the HTLC has already expired, potentially merge it with the + // rest of the claim transaction, as above. + let input = TxIn { + previous_output: BitcoinOutPoint { + txid: commitment_txid, + vout: transaction_output_index, + }, + script_sig: Script::new(), + sequence: idx as u32, + witness: Vec::new(), + }; + let mut timeout_tx = Transaction { version: 2, - lock_time: 0, + lock_time: htlc.cltv_expiry, input: vec![input], output: vec!(TxOut { script_pubkey: self.destination_script.clone(), - value: htlc.amount_msat / 1000, //TODO: - fee + value: htlc.amount_msat / 1000, }), }; - 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); + let sighash_parts = bip143::SighashComponents::new(&timeout_tx); + sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]); + txn_to_broadcast.push(timeout_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 + if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx let outputs = vec!(TxOut { script_pubkey: self.destination_script.clone(), - value: total_value, //TODO: - fee + value: total_value }); let mut spend_tx = Transaction { version: 2, @@ -1174,13 +1478,14 @@ impl ChannelMonitor { input: inputs, output: outputs, }; + spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..])) / 1000; let mut values_drain = values.drain(..); let sighash_parts = bip143::SighashComponents::new(&spend_tx); for input in spend_tx.input.iter_mut() { let value = values_drain.next().unwrap(); - sign_input!(sighash_parts, input, value.0, value.1.to_vec()); + sign_input!(sighash_parts, input, value.0, (value.1).0.to_vec()); } spendable_outputs.push(SpendableOutputDescriptor::StaticOutput { @@ -1192,11 +1497,11 @@ impl ChannelMonitor { } } - (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs) + (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated) } - /// 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, Option) { + /// Attempts 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, fee_estimator: &FeeEstimator) -> (Option, Option) { if tx.input.len() != 1 || tx.output.len() != 1 { return (None, None) } @@ -1211,13 +1516,13 @@ impl ChannelMonitor { } let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (None, None); }; - let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret)); + let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret)); let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key); let revocation_pubkey = match self.key_storage { - KeyStorage::PrivMode { ref revocation_base_key, .. } => { + Storage::Local { ref revocation_base_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))) }, - KeyStorage::SigsMode { ref revocation_base_key, .. } => { + Storage::Watchtower { ref revocation_base_key, .. } => { ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)) }, }; @@ -1248,7 +1553,7 @@ impl ChannelMonitor { if !inputs.is_empty() { let outputs = vec!(TxOut { script_pubkey: self.destination_script.clone(), - value: amount, //TODO: - fee + value: amount }); let mut spend_tx = Transaction { @@ -1257,20 +1562,21 @@ impl ChannelMonitor { input: inputs, output: outputs, }; + spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&vec![InputDescriptors::RevokedOutput])) / 1000; let sighash_parts = bip143::SighashComponents::new(&spend_tx); let sig = match self.key_storage { - KeyStorage::PrivMode { ref revocation_base_key, .. } => { - let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..])); + Storage::Local { ref revocation_base_key, .. } => { + let sighash = hash_to_message!(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]); let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key)); self.secp_ctx.sign(&sighash, &revocation_key) } - KeyStorage::SigsMode { .. } => { + Storage::Watchtower { .. } => { unimplemented!(); } }; - spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec()); + spend_tx.input[0].witness.push(sig.serialize_der().to_vec()); spend_tx.input[0].witness[0].push(SigHashType::All as u8); spend_tx.input[0].witness.push(vec!(1)); spend_tx.input[0].witness.push(redeemscript.into_bytes()); @@ -1281,9 +1587,10 @@ impl ChannelMonitor { } else { (None, None) } } - fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option, delayed_payment_base_key: &Option) -> (Vec, Vec) { + fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option, delayed_payment_base_key: &Option) -> (Vec, Vec, Vec) { let mut res = Vec::with_capacity(local_tx.htlc_outputs.len()); let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len()); + let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len()); macro_rules! add_dynamic_output { ($father_tx: expr, $vout: expr) => { @@ -1313,84 +1620,100 @@ impl ChannelMonitor { } } - for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() { - if htlc.offered { - let mut htlc_timeout_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key); + for &(ref htlc, ref sigs, _) in local_tx.htlc_outputs.iter() { + if let Some(transaction_output_index) = htlc.transaction_output_index { + if let &Some((ref their_sig, ref our_sig)) = sigs { + if htlc.offered { + log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions"); + let mut htlc_timeout_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key); - htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy + htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy - htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec()); - htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8); - htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec()); - htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8); + htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der().to_vec()); + htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8); + htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der().to_vec()); + htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8); - 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()); + 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()); - add_dynamic_output!(htlc_timeout_tx, 0); - res.push(htlc_timeout_tx); - } else { - if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) { - let mut htlc_success_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key); + add_dynamic_output!(htlc_timeout_tx, 0); + res.push(htlc_timeout_tx); + } else { + if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) { + log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions"); + let mut htlc_success_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key); - htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy + htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy - htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec()); - htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8); - htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec()); - htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8); + htlc_success_tx.input[0].witness.push(their_sig.serialize_der().to_vec()); + htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8); + htlc_success_tx.input[0].witness.push(our_sig.serialize_der().to_vec()); + htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8); - 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()); + htlc_success_tx.input[0].witness.push(payment_preimage.0.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()); - add_dynamic_output!(htlc_success_tx, 0); - res.push(htlc_success_tx); - } + add_dynamic_output!(htlc_success_tx, 0); + res.push(htlc_success_tx); + } + } + watch_outputs.push(local_tx.tx.output[transaction_output_index as usize].clone()); + } else { panic!("Should have sigs for non-dust local tx outputs!") } } } - (res, spendable_outputs) + (res, spendable_outputs, watch_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, Vec) { + fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec, Vec, (Sha256dHash, Vec)) { let commitment_txid = tx.txid(); + // TODO: If we find a match here we need to fail back HTLCs that weren't included in the + // broadcast commitment transaction, either because they didn't meet dust or because they + // weren't yet included in our commitment transaction(s). if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx { if local_tx.txid == commitment_txid { + log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim"); match self.key_storage { - KeyStorage::PrivMode { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => { - return self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key)); + Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => { + let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key)); + return (local_txn, spendable_outputs, (commitment_txid, watch_outputs)); }, - KeyStorage::SigsMode { .. } => { - return self.broadcast_by_local_state(local_tx, &None, &None); + Storage::Watchtower { .. } => { + let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None); + return (local_txn, spendable_outputs, (commitment_txid, watch_outputs)); } } } } if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx { if local_tx.txid == commitment_txid { + log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim"); match self.key_storage { - KeyStorage::PrivMode { 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)); + Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => { + let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)); + return (local_txn, spendable_outputs, (commitment_txid, watch_outputs)); }, - KeyStorage::SigsMode { .. } => { - return self.broadcast_by_local_state(local_tx, &None, &None); + Storage::Watchtower { .. } => { + let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None); + return (local_txn, spendable_outputs, (commitment_txid, watch_outputs)); } } } } - (Vec::new(), Vec::new()) + (Vec::new(), Vec::new(), (commitment_txid, Vec::new())) } /// Generate a spendable output event when closing_transaction get registered onchain. fn check_spend_closing_transaction(&self, tx: &Transaction) -> Option { if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 { match self.key_storage { - KeyStorage::PrivMode { ref shutdown_pubkey, .. } => { - let our_channel_close_key_hash = Hash160::from_data(&shutdown_pubkey.serialize()); - let shutdown_script = Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script(); + Storage::Local { ref shutdown_pubkey, .. } => { + let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize()); + let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script(); for (idx, output) in tx.output.iter().enumerate() { if shutdown_script == output.script_pubkey { return Some(SpendableOutputDescriptor::StaticOutput { @@ -1400,9 +1723,9 @@ impl ChannelMonitor { } } } - KeyStorage::SigsMode { .. } => { + Storage::Watchtower { .. } => { //TODO: we need to ensure an offline client will generate the event when it - // cames back online after only the watchtower saw the transaction + // comes back online after only the watchtower saw the transaction } } } @@ -1415,7 +1738,7 @@ impl ChannelMonitor { if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx { let mut res = vec![local_tx.tx.clone()]; match self.key_storage { - KeyStorage::PrivMode { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => { + Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => { res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)).0); }, _ => panic!("Can only broadcast by local channelmonitor"), @@ -1426,9 +1749,10 @@ impl ChannelMonitor { } } - fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface)-> (Vec<(Sha256dHash, Vec)>, Vec) { + fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface, fee_estimator: &FeeEstimator)-> (Vec<(Sha256dHash, Vec)>, Vec, Vec<(HTLCSource, Option, PaymentHash)>) { let mut watch_outputs = Vec::new(); let mut spendable_outputs = Vec::new(); + let mut htlc_updated = 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), @@ -1437,26 +1761,40 @@ impl ChannelMonitor { // filters. let prevout = &tx.input[0].previous_output; let mut txn: Vec = 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, mut spendable_output) = self.check_spend_remote_transaction(tx, height); + let funding_txo = match self.key_storage { + Storage::Local { ref funding_info, .. } => { + funding_info.clone() + } + Storage::Watchtower { .. } => { + unimplemented!(); + } + }; + if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) { + let (remote_txn, new_outputs, mut spendable_output, mut updated) = self.check_spend_remote_transaction(tx, height, fee_estimator); txn = remote_txn; spendable_outputs.append(&mut spendable_output); if !new_outputs.1.is_empty() { watch_outputs.push(new_outputs); } if txn.is_empty() { - let (remote_txn, mut outputs) = self.check_spend_local_transaction(tx, height); - spendable_outputs.append(&mut outputs); - txn = remote_txn; + let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height); + spendable_outputs.append(&mut spendable_output); + txn = local_txn; + if !new_outputs.1.is_empty() { + watch_outputs.push(new_outputs); + } } - if !self.funding_txo.is_none() && txn.is_empty() { + if !funding_txo.is_none() && txn.is_empty() { if let Some(spendable_output) = self.check_spend_closing_transaction(tx) { spendable_outputs.push(spendable_output); } } + if updated.len() > 0 { + htlc_updated.append(&mut updated); + } } else { if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) { - let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number); + let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number, fee_estimator); if let Some(tx) = tx { txn.push(tx); } @@ -1469,21 +1807,34 @@ impl ChannelMonitor { broadcaster.broadcast_transaction(tx); } } + // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs + // can also be resolved in a few other ways which can have more than one output. Thus, + // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check. + let mut updated = self.is_resolving_htlc_output(tx); + if updated.len() > 0 { + htlc_updated.append(&mut updated); + } } 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); match self.key_storage { - KeyStorage::PrivMode { ref delayed_payment_base_key, 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); + Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => { + let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key)); + spendable_outputs.append(&mut spendable_output); + if !new_outputs.is_empty() { + watch_outputs.push((cur_local_tx.txid.clone(), new_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); + Storage::Watchtower { .. } => { + let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None); + spendable_outputs.append(&mut spendable_output); + if !new_outputs.is_empty() { + watch_outputs.push((cur_local_tx.txid.clone(), new_outputs)); + } for tx in txs { broadcaster.broadcast_transaction(&tx); } @@ -1492,40 +1843,191 @@ impl ChannelMonitor { } } self.last_block_hash = block_hash.clone(); - (watch_outputs, spendable_outputs) + (watch_outputs, spendable_outputs, htlc_updated) } pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool { + // We need to consider all HTLCs which are: + // * in any unrevoked remote commitment transaction, as they could broadcast said + // transactions and we'd end up in a race, or + // * are in our latest local commitment transaction, as this is the thing we will + // broadcast if we go on-chain. + // Note that we consider HTLCs which were below dust threshold here - while they don't + // strictly imply that we need to fail the channel, we need to go ahead and fail them back + // to the source, and if we don't fail the channel we will have to ensure that the next + // updates that peer sends us are update_fails, failing the channel if not. It's probably + // easier to just fail the channel as this case should be rare enough anyway. + macro_rules! scan_commitment { + ($htlcs: expr, $local_tx: expr) => { + for ref htlc in $htlcs { + // For inbound HTLCs which we know the preimage for, we have to ensure we hit the + // chain with enough room to claim the HTLC without our counterparty being able to + // time out the HTLC first. + // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary + // concern is being able to claim the corresponding inbound HTLC (on another + // channel) before it expires. In fact, we don't even really care if our + // counterparty here claims such an outbound HTLC after it expired as long as we + // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the + // chain when our counterparty is waiting for expiration to off-chain fail an HTLC + // we give ourselves a few blocks of headroom after expiration before going + // on-chain for an expired HTLC. + // Note that, to avoid a potential attack whereby a node delays claiming an HTLC + // from us until we've reached the point where we go on-chain with the + // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at + // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC. + // aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER + // inbound_cltv == height + CLTV_CLAIM_BUFFER + // outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER + // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv + // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion) + // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA + // The final, above, condition is checked for statically in channelmanager + // with CHECK_CLTV_EXPIRY_SANITY_2. + let htlc_outbound = $local_tx == htlc.offered; + if ( htlc_outbound && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) || + (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) { + log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry); + return true; + } + } + } + } + if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx { - for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() { - // For inbound HTLCs which we know the preimage for, we have to ensure we hit the - // chain with enough room to claim the HTLC without our counterparty being able to - // time out the HTLC first. - // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary - // concern is being able to claim the corresponding inbound HTLC (on another - // channel) before it expires. In fact, we don't even really care if our - // counterparty here claims such an outbound HTLC after it expired as long as we - // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the - // chain when our counterparty is waiting for expiration to off-chain fail an HTLC - // we give ourselves a few blocks of headroom after expiration before going - // on-chain for an expired HTLC. - // Note that, to avoid a potential attack whereby a node delays claiming an HTLC - // from us until we've reached the point where we go on-chain with the - // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at - // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC. - // aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER - // inbound_cltv == height + CLTV_CLAIM_BUFFER - // outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFER <= inbound_cltv - CLTV_CLAIM_BUFFER - // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= inbound_cltv - outbound_cltv - // HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= CLTV_EXPIRY_DELTA - if ( htlc.offered && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) || - (!htlc.offered && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) { - return true; + scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true); + } + + if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage { + if let &Some(ref txid) = current_remote_commitment_txid { + if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) { + scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false); + } + } + if let &Some(ref txid) = prev_remote_commitment_txid { + if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) { + scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false); } } } + false } + + /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local + /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC + fn is_resolving_htlc_output(&mut self, tx: &Transaction) -> Vec<(HTLCSource, Option, PaymentHash)> { + let mut htlc_updated = Vec::new(); + + 'outer_loop: for input in &tx.input { + let mut payment_data = None; + let revocation_sig_claim = (input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33) + || (input.witness.len() == 3 && input.witness[2].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33); + let accepted_preimage_claim = input.witness.len() == 5 && input.witness[4].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT; + let offered_preimage_claim = input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT; + + macro_rules! log_claim { + ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => { + // We found the output in question, but aren't failing it backwards + // as we have no corresponding source and no valid remote commitment txid + // to try a weak source binding with same-hash, same-value still-valid offered HTLC. + // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction. + let outbound_htlc = $local_tx == $htlc.offered; + if ($local_tx && revocation_sig_claim) || + (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) { + log_error!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!", + $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(), + if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0), + if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" }); + } else { + log_info!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}", + $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(), + if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0), + if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" }); + } + } + } + + macro_rules! check_htlc_valid_remote { + ($remote_txid: expr, $htlc_output: expr) => { + if let &Some(txid) = $remote_txid { + for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() { + if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat { + if let &Some(ref source) = pending_source { + log_claim!("revoked remote commitment tx", false, pending_htlc, true); + payment_data = Some(((**source).clone(), $htlc_output.payment_hash)); + break; + } + } + } + } + } + } + + macro_rules! scan_commitment { + ($htlcs: expr, $tx_info: expr, $local_tx: expr) => { + for (ref htlc_output, source_option) in $htlcs { + if Some(input.previous_output.vout) == htlc_output.transaction_output_index { + if let Some(ref source) = source_option { + log_claim!($tx_info, $local_tx, htlc_output, true); + // We have a resolution of an HTLC either from one of our latest + // local commitment transactions or an unrevoked remote commitment + // transaction. This implies we either learned a preimage, the HTLC + // has timed out, or we screwed up. In any case, we should now + // resolve the source HTLC with the original sender. + payment_data = Some(((*source).clone(), htlc_output.payment_hash)); + } else if !$local_tx { + if let Storage::Local { ref current_remote_commitment_txid, .. } = self.key_storage { + check_htlc_valid_remote!(current_remote_commitment_txid, htlc_output); + } + if payment_data.is_none() { + if let Storage::Local { ref prev_remote_commitment_txid, .. } = self.key_storage { + check_htlc_valid_remote!(prev_remote_commitment_txid, htlc_output); + } + } + } + if payment_data.is_none() { + log_claim!($tx_info, $local_tx, htlc_output, false); + continue 'outer_loop; + } + } + } + } + } + + if let Some(ref current_local_signed_commitment_tx) = self.current_local_signed_commitment_tx { + if input.previous_output.txid == current_local_signed_commitment_tx.txid { + scan_commitment!(current_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())), + "our latest local commitment tx", true); + } + } + if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx { + if input.previous_output.txid == prev_local_signed_commitment_tx.txid { + scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())), + "our previous local commitment tx", true); + } + } + if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) { + scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))), + "remote commitment tx", false); + } + + // Check that scan_commitment, above, decided there is some source worth relaying an + // HTLC resolution backwards to and figure out whether we learned a preimage from it. + if let Some((source, payment_hash)) = payment_data { + let mut payment_preimage = PaymentPreimage([0; 32]); + if accepted_preimage_claim { + payment_preimage.0.copy_from_slice(&input.witness[3]); + htlc_updated.push((source, Some(payment_preimage), payment_hash)); + } else if offered_preimage_claim { + payment_preimage.0.copy_from_slice(&input.witness[1]); + htlc_updated.push((source, Some(payment_preimage), payment_hash)); + } else { + htlc_updated.push((source, None, payment_hash)); + } + } + } + htlc_updated + } } const MAX_ALLOC_SIZE: usize = 64*1024; @@ -1548,13 +2050,6 @@ impl ReadableArgs> for (Sha256dHash, ChannelM return Err(DecodeError::UnknownVersion); } - // 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. - let outpoint = OutPoint { - txid: Readable::read(reader)?, - index: Readable::read(reader)?, - }; - let funding_txo = Some((outpoint, Readable::read(reader)?)); let commitment_transaction_number_obscure_factor = >::read(reader)?.0; let key_storage = match >::read(reader)? { @@ -1564,17 +2059,18 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let delayed_payment_base_key = Readable::read(reader)?; let payment_base_key = Readable::read(reader)?; let shutdown_pubkey = Readable::read(reader)?; - let prev_latest_per_commitment_point = match >::read(reader)? { - 0 => None, - 1 => Some(Readable::read(reader)?), - _ => return Err(DecodeError::InvalidValue), - }; - let latest_per_commitment_point = match >::read(reader)? { - 0 => None, - 1 => Some(Readable::read(reader)?), - _ => return Err(DecodeError::InvalidValue), + let prev_latest_per_commitment_point = Readable::read(reader)?; + let latest_per_commitment_point = 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. + let outpoint = OutPoint { + txid: Readable::read(reader)?, + index: Readable::read(reader)?, }; - KeyStorage::PrivMode { + let funding_info = Some((outpoint, Readable::read(reader)?)); + let current_remote_commitment_txid = Readable::read(reader)?; + let prev_remote_commitment_txid = Readable::read(reader)?; + Storage::Local { revocation_base_key, htlc_base_key, delayed_payment_base_key, @@ -1582,6 +2078,9 @@ impl ReadableArgs> for (Sha256dHash, ChannelM shutdown_pubkey, prev_latest_per_commitment_point, latest_per_commitment_point, + funding_info, + current_remote_commitment_txid, + prev_remote_commitment_txid, } }, _ => return Err(DecodeError::InvalidValue), @@ -1600,7 +2099,7 @@ impl ReadableArgs> for (Sha256dHash, ChannelM if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 { Some((first_idx, first_point, None)) } else { - Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, &second_point_slice))))) + Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice))))) } } }; @@ -1620,8 +2119,8 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let offered: bool = Readable::read(reader)?; let amount_msat: u64 = Readable::read(reader)?; let cltv_expiry: u32 = Readable::read(reader)?; - let payment_hash: [u8; 32] = Readable::read(reader)?; - let transaction_output_index: u32 = Readable::read(reader)?; + let payment_hash: PaymentHash = Readable::read(reader)?; + let transaction_output_index: Option = Readable::read(reader)?; HTLCOutputInCommitment { offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index @@ -1634,12 +2133,12 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64)); for _ in 0..remote_claimable_outpoints_len { let txid: Sha256dHash = Readable::read(reader)?; - let outputs_count: u64 = Readable::read(reader)?; - let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 32)); - for _ in 0..outputs_count { - outputs.push(read_htlc_in_commitment!()); + let htlcs_count: u64 = Readable::read(reader)?; + let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32)); + for _ in 0..htlcs_count { + htlcs.push((read_htlc_in_commitment!(), as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o)))); } - if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) { + if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) { return Err(DecodeError::InvalidValue); } } @@ -1662,9 +2161,9 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let remote_hash_commitment_number_len: u64 = Readable::read(reader)?; let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32)); for _ in 0..remote_hash_commitment_number_len { - let txid: [u8; 32] = Readable::read(reader)?; + let payment_hash: PaymentHash = Readable::read(reader)?; let commitment_number = >::read(reader)?.0; - if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) { + if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) { return Err(DecodeError::InvalidValue); } } @@ -1691,15 +2190,22 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let delayed_payment_key = Readable::read(reader)?; let feerate_per_kw: u64 = Readable::read(reader)?; - let htlc_outputs_len: u64 = Readable::read(reader)?; - let mut htlc_outputs = Vec::with_capacity(cmp::min(htlc_outputs_len as usize, MAX_ALLOC_SIZE / 128)); - for _ in 0..htlc_outputs_len { - htlc_outputs.push((read_htlc_in_commitment!(), Readable::read(reader)?, Readable::read(reader)?)); + let htlcs_len: u64 = Readable::read(reader)?; + let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128)); + for _ in 0..htlcs_len { + let htlc = read_htlc_in_commitment!(); + let sigs = match >::read(reader)? { + 0 => None, + 1 => Some((Readable::read(reader)?, Readable::read(reader)?)), + _ => return Err(DecodeError::InvalidValue), + }; + htlcs.push((htlc, sigs, Readable::read(reader)?)); } LocalSignedTx { txid: tx.txid(), - tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs + tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, + htlc_outputs: htlcs } } } @@ -1725,13 +2231,9 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let payment_preimages_len: u64 = Readable::read(reader)?; let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32)); - let mut sha = Sha256::new(); for _ in 0..payment_preimages_len { - let preimage: [u8; 32] = Readable::read(reader)?; - sha.reset(); - sha.input(&preimage); - let mut hash = [0; 32]; - sha.result(&mut hash); + let preimage: PaymentPreimage = Readable::read(reader)?; + let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner()); if let Some(_) = payment_preimages.insert(hash, preimage) { return Err(DecodeError::InvalidValue); } @@ -1741,7 +2243,6 @@ impl ReadableArgs> for (Sha256dHash, ChannelM let destination_script = Readable::read(reader)?; Ok((last_block_hash.clone(), ChannelMonitor { - funding_txo, commitment_transaction_number_obscure_factor, key_storage, @@ -1774,16 +2275,23 @@ impl ReadableArgs> for (Sha256dHash, ChannelM #[cfg(test)] mod tests { - use bitcoin::blockdata::script::Script; - use bitcoin::blockdata::transaction::Transaction; - use crypto::digest::Digest; + use bitcoin::blockdata::script::{Script, Builder}; + use bitcoin::blockdata::opcodes; + use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType}; + use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint; + use bitcoin::util::bip143; + use bitcoin_hashes::Hash; + use bitcoin_hashes::sha256::Hash as Sha256; + use bitcoin_hashes::sha256d::Hash as Sha256dHash; + use bitcoin_hashes::hex::FromHex; use hex; - use ln::channelmonitor::ChannelMonitor; + use ln::channelmanager::{PaymentPreimage, PaymentHash}; + use ln::channelmonitor::{ChannelMonitor, InputDescriptors}; + use ln::chan_utils; use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys}; - use util::sha2::Sha256; use util::test_utils::TestLogger; use secp256k1::key::{SecretKey,PublicKey}; - use secp256k1::{Secp256k1, Signature}; + use secp256k1::Secp256k1; use rand::{thread_rng,Rng}; use std::sync::Arc; @@ -1809,7 +2317,7 @@ mod tests { { // insert_secret correct sequence - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -1855,7 +2363,7 @@ mod tests { { // insert_secret #1 incorrect - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -1871,7 +2379,7 @@ mod tests { { // insert_secret #2 incorrect (#1 derived from incorrect) - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -1897,7 +2405,7 @@ mod tests { { // insert_secret #3 incorrect - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -1923,7 +2431,7 @@ mod tests { { // insert_secret #4 incorrect (1,2,3 derived from incorrect) - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -1969,7 +2477,7 @@ mod tests { { // insert_secret #5 incorrect - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -2005,7 +2513,7 @@ mod tests { { // insert_secret #6 incorrect (5 derived from incorrect) - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -2051,7 +2559,7 @@ mod tests { { // insert_secret #7 incorrect - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -2097,7 +2605,7 @@ mod tests { { // insert_secret #8 incorrect - 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(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); secrets.clear(); secrets.push([0; 32]); @@ -2146,9 +2654,8 @@ mod tests { fn test_prune_preimages() { let secp_ctx = Secp256k1::new(); let logger = Arc::new(TestLogger::new()); - let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap(); - let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap()); + let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); macro_rules! dummy_keys { () => { { @@ -2169,12 +2676,9 @@ mod tests { { let mut rng = thread_rng(); for _ in 0..20 { - let mut preimage = [0; 32]; - rng.fill_bytes(&mut preimage); - let mut sha = Sha256::new(); - sha.input(&preimage); - let mut hash = [0; 32]; - sha.result(&mut hash); + let mut preimage = PaymentPreimage([0; 32]); + rng.fill_bytes(&mut preimage.0[..]); + let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner()); preimages.push((preimage, hash)); } } @@ -2184,13 +2688,13 @@ mod tests { { let mut res = Vec::new(); for (idx, preimage) in $preimages_slice.iter().enumerate() { - res.push(HTLCOutputInCommitment { + res.push((HTLCOutputInCommitment { offered: true, amount_msat: 0, cltv_expiry: 0, payment_hash: preimage.1.clone(), - transaction_output_index: idx as u32, - }); + transaction_output_index: Some(idx as u32), + }, None)); } res } @@ -2200,7 +2704,7 @@ mod tests { ($preimages_slice: expr) => { { let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice); - let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect(); + let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect(); res } } @@ -2216,7 +2720,7 @@ mod tests { // Prune with one old state and a local commitment tx holding a few overlaps with the // old state. - let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone()); + let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone()); monitor.set_their_to_self_delay(10); monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10])); @@ -2260,5 +2764,117 @@ mod tests { test_preimages_exist!(&preimages[0..5], monitor); } + #[test] + fn test_claim_txn_weight_computation() { + // We test Claim txn weight, knowing that we want expected weigth and + // not actual case to avoid sigs and time-lock delays hell variances. + + let secp_ctx = Secp256k1::new(); + let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap(); + let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey); + let mut sum_actual_sigs: u64 = 0; + + macro_rules! sign_input { + ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => { + let htlc = HTLCOutputInCommitment { + offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false }, + amount_msat: 0, + cltv_expiry: 2 << 16, + payment_hash: PaymentHash([1; 32]), + transaction_output_index: Some($idx), + }; + let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) }; + let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]); + let sig = secp_ctx.sign(&sighash, &privkey); + $input.witness.push(sig.serialize_der().to_vec()); + $input.witness[0].push(SigHashType::All as u8); + sum_actual_sigs += $input.witness[0].len() as u64; + if *$input_type == InputDescriptors::RevokedOutput { + $input.witness.push(vec!(1)); + } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC { + $input.witness.push(pubkey.clone().serialize().to_vec()); + } else if *$input_type == InputDescriptors::ReceivedHTLC { + $input.witness.push(vec![0]); + } else { + $input.witness.push(PaymentPreimage([1; 32]).0.to_vec()); + } + $input.witness.push(redeem_script.into_bytes()); + println!("witness[0] {}", $input.witness[0].len()); + println!("witness[1] {}", $input.witness[1].len()); + println!("witness[2] {}", $input.witness[2].len()); + } + } + + let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script(); + let txid = Sha256dHash::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap(); + + // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs + let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() }; + for i in 0..4 { + claim_tx.input.push(TxIn { + previous_output: BitcoinOutPoint { + txid, + vout: i, + }, + script_sig: Script::new(), + sequence: 0xfffffffd, + witness: Vec::new(), + }); + } + claim_tx.output.push(TxOut { + script_pubkey: script_pubkey.clone(), + value: 0, + }); + let base_weight = claim_tx.get_weight(); + let sighash_parts = bip143::SighashComponents::new(&claim_tx); + let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC]; + for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() { + sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs); + } + assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs)); + + // Claim tx with 1 offered HTLCs, 3 received HTLCs + claim_tx.input.clear(); + sum_actual_sigs = 0; + for i in 0..4 { + claim_tx.input.push(TxIn { + previous_output: BitcoinOutPoint { + txid, + vout: i, + }, + script_sig: Script::new(), + sequence: 0xfffffffd, + witness: Vec::new(), + }); + } + let base_weight = claim_tx.get_weight(); + let sighash_parts = bip143::SighashComponents::new(&claim_tx); + let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC]; + for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() { + sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs); + } + assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs)); + + // Justice tx with 1 revoked HTLC-Success tx output + claim_tx.input.clear(); + sum_actual_sigs = 0; + claim_tx.input.push(TxIn { + previous_output: BitcoinOutPoint { + txid, + vout: 0, + }, + script_sig: Script::new(), + sequence: 0xfffffffd, + witness: Vec::new(), + }); + let base_weight = claim_tx.get_weight(); + let sighash_parts = bip143::SighashComponents::new(&claim_tx); + let inputs_des = vec![InputDescriptors::RevokedOutput]; + for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() { + sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs); + } + assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() as u64 - sum_actual_sigs)); + } + // Further testing is done in the ChannelManager integration tests. }