Batch-sign local HTLC txn with a well-doc'd API, returning sigs
[rust-lightning] / lightning / src / ln / onchaintx.rs
1 //! The logic to build claims and bump in-flight transactions until confirmations.
2 //!
3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
4 //! building, tracking, bumping and notifications functions.
5
6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
8 use bitcoin::blockdata::script::Script;
9 use bitcoin::util::bip143;
10
11 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
12
13 use secp256k1::{Secp256k1, Signature};
14 use secp256k1;
15
16 use ln::msgs::DecodeError;
17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
18 use ln::channelmanager::PaymentPreimage;
19 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction};
20 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
21 use chain::keysinterface::ChannelKeys;
22 use util::logger::Logger;
23 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
24 use util::byte_utils;
25
26 use std::collections::{HashMap, hash_map};
27 use std::sync::Arc;
28 use std::cmp;
29 use std::ops::Deref;
30
31 const MAX_ALLOC_SIZE: usize = 64*1024;
32
33 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
34 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
35 #[derive(Clone, PartialEq)]
36 enum OnchainEvent {
37         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
38         /// bump-txn candidate buffer.
39         Claim {
40                 claim_request: Sha256dHash,
41         },
42         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
43         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
44         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
45         ContentiousOutpoint {
46                 outpoint: BitcoinOutPoint,
47                 input_material: InputMaterial,
48         }
49 }
50
51 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
52 #[derive(Clone, PartialEq)]
53 pub struct ClaimTxBumpMaterial {
54         // At every block tick, used to check if pending claiming tx is taking too
55         // much time for confirmation and we need to bump it.
56         height_timer: Option<u32>,
57         // Tracked in case of reorg to wipe out now-superflous bump material
58         feerate_previous: u64,
59         // Soonest timelocks among set of outpoints claimed, used to compute
60         // a priority of not feerate
61         soonest_timelock: u32,
62         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
63         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
64 }
65
66 impl Writeable for ClaimTxBumpMaterial  {
67         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
68                 self.height_timer.write(writer)?;
69                 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
70                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
71                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
72                 for (outp, tx_material) in self.per_input_material.iter() {
73                         outp.write(writer)?;
74                         tx_material.write(writer)?;
75                 }
76                 Ok(())
77         }
78 }
79
80 impl Readable for ClaimTxBumpMaterial {
81         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
82                 let height_timer = Readable::read(reader)?;
83                 let feerate_previous = Readable::read(reader)?;
84                 let soonest_timelock = Readable::read(reader)?;
85                 let per_input_material_len: u64 = Readable::read(reader)?;
86                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
87                 for _ in 0 ..per_input_material_len {
88                         let outpoint = Readable::read(reader)?;
89                         let input_material = Readable::read(reader)?;
90                         per_input_material.insert(outpoint, input_material);
91                 }
92                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
93         }
94 }
95
96 #[derive(PartialEq)]
97 pub(super) enum InputDescriptors {
98         RevokedOfferedHTLC,
99         RevokedReceivedHTLC,
100         OfferedHTLC,
101         ReceivedHTLC,
102         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
103 }
104
105 macro_rules! subtract_high_prio_fee {
106         ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
107                 {
108                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
109                         let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
110                         if $value <= fee {
111                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
112                                 fee = $used_feerate * ($predicted_weight as u64) / 1000;
113                                 if $value <= fee {
114                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
115                                         fee = $used_feerate * ($predicted_weight as u64) / 1000;
116                                         if $value <= fee {
117                                                 log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
118                                                         fee, $value);
119                                                 false
120                                         } else {
121                                                 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
122                                                         $value);
123                                                 $value -= fee;
124                                                 true
125                                         }
126                                 } else {
127                                         log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
128                                                 $value);
129                                         $value -= fee;
130                                         true
131                                 }
132                         } else {
133                                 $value -= fee;
134                                 true
135                         }
136                 }
137         }
138 }
139
140 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
141         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
142                 match Readable::read(reader)? {
143                         0u8 => Ok(None),
144                         1u8 => {
145                                 let vlen: u64 = Readable::read(reader)?;
146                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
147                                 for _ in 0..vlen {
148                                         ret.push(match Readable::read(reader)? {
149                                                 0u8 => None,
150                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
151                                                 _ => return Err(DecodeError::InvalidValue)
152                                         });
153                                 }
154                                 Ok(Some(ret))
155                         },
156                         _ => Err(DecodeError::InvalidValue),
157                 }
158         }
159 }
160
161 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
162         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
163                 match self {
164                         &Some(ref vec) => {
165                                 1u8.write(writer)?;
166                                 (vec.len() as u64).write(writer)?;
167                                 for opt in vec.iter() {
168                                         match opt {
169                                                 &Some((ref idx, ref sig)) => {
170                                                         1u8.write(writer)?;
171                                                         (*idx as u64).write(writer)?;
172                                                         sig.write(writer)?;
173                                                 },
174                                                 &None => 0u8.write(writer)?,
175                                         }
176                                 }
177                         },
178                         &None => 0u8.write(writer)?,
179                 }
180                 Ok(())
181         }
182 }
183
184
185 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
186 /// do RBF bumping if possible.
187 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
188         destination_script: Script,
189         local_commitment: Option<LocalCommitmentTransaction>,
190         // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
191         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
192         // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
193         // the commitment transaction).
194         local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
195         prev_local_commitment: Option<LocalCommitmentTransaction>,
196         prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
197         local_csv: u16,
198
199         key_storage: ChanSigner,
200
201         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
202         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
203         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
204         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
205         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
206         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
207         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
208         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
209         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
210         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
211         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
212         #[cfg(test)] // Used in functional_test to verify sanitization
213         pub pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
214         #[cfg(not(test))]
215         pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
216
217         // Used to link outpoints claimed in a connected block to a pending claim request.
218         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
219         // Value is (pending claim request identifier, confirmation_block), identifier
220         // is txid of the initial claiming transaction and is immutable until outpoint is
221         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
222         // block with output gets disconnected.
223         #[cfg(test)] // Used in functional_test to verify sanitization
224         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
225         #[cfg(not(test))]
226         claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
227
228         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
229
230         secp_ctx: Secp256k1<secp256k1::All>,
231         logger: Arc<Logger>
232 }
233
234 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
235         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
236                 self.destination_script.write(writer)?;
237                 self.local_commitment.write(writer)?;
238                 self.local_htlc_sigs.write(writer)?;
239                 self.prev_local_commitment.write(writer)?;
240                 self.prev_local_htlc_sigs.write(writer)?;
241
242                 self.local_csv.write(writer)?;
243
244                 self.key_storage.write(writer)?;
245
246                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
247                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
248                         ancestor_claim_txid.write(writer)?;
249                         claim_tx_data.write(writer)?;
250                 }
251
252                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
253                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
254                         outp.write(writer)?;
255                         claim_and_height.0.write(writer)?;
256                         claim_and_height.1.write(writer)?;
257                 }
258
259                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
260                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
261                         writer.write_all(&byte_utils::be32_to_array(**target))?;
262                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
263                         for ev in events.iter() {
264                                 match *ev {
265                                         OnchainEvent::Claim { ref claim_request } => {
266                                                 writer.write_all(&[0; 1])?;
267                                                 claim_request.write(writer)?;
268                                         },
269                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
270                                                 writer.write_all(&[1; 1])?;
271                                                 outpoint.write(writer)?;
272                                                 input_material.write(writer)?;
273                                         }
274                                 }
275                         }
276                 }
277                 Ok(())
278         }
279 }
280
281 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
282         fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
283                 let destination_script = Readable::read(reader)?;
284
285                 let local_commitment = Readable::read(reader)?;
286                 let local_htlc_sigs = Readable::read(reader)?;
287                 let prev_local_commitment = Readable::read(reader)?;
288                 let prev_local_htlc_sigs = Readable::read(reader)?;
289
290                 let local_csv = Readable::read(reader)?;
291
292                 let key_storage = Readable::read(reader)?;
293
294                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
295                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
296                 for _ in 0..pending_claim_requests_len {
297                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
298                 }
299
300                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
301                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
302                 for _ in 0..claimable_outpoints_len {
303                         let outpoint = Readable::read(reader)?;
304                         let ancestor_claim_txid = Readable::read(reader)?;
305                         let height = Readable::read(reader)?;
306                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
307                 }
308                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
309                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
310                 for _ in 0..waiting_threshold_conf_len {
311                         let height_target = Readable::read(reader)?;
312                         let events_len: u64 = Readable::read(reader)?;
313                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
314                         for _ in 0..events_len {
315                                 let ev = match <u8 as Readable>::read(reader)? {
316                                         0 => {
317                                                 let claim_request = Readable::read(reader)?;
318                                                 OnchainEvent::Claim {
319                                                         claim_request
320                                                 }
321                                         },
322                                         1 => {
323                                                 let outpoint = Readable::read(reader)?;
324                                                 let input_material = Readable::read(reader)?;
325                                                 OnchainEvent::ContentiousOutpoint {
326                                                         outpoint,
327                                                         input_material
328                                                 }
329                                         }
330                                         _ => return Err(DecodeError::InvalidValue),
331                                 };
332                                 events.push(ev);
333                         }
334                         onchain_events_waiting_threshold_conf.insert(height_target, events);
335                 }
336
337                 Ok(OnchainTxHandler {
338                         destination_script,
339                         local_commitment,
340                         local_htlc_sigs,
341                         prev_local_commitment,
342                         prev_local_htlc_sigs,
343                         local_csv,
344                         key_storage,
345                         claimable_outpoints,
346                         pending_claim_requests,
347                         onchain_events_waiting_threshold_conf,
348                         secp_ctx: Secp256k1::new(),
349                         logger,
350                 })
351         }
352 }
353
354 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
355         pub(super) fn new(destination_script: Script, keys: ChanSigner, local_csv: u16, logger: Arc<Logger>) -> Self {
356
357                 let key_storage = keys;
358
359                 OnchainTxHandler {
360                         destination_script,
361                         local_commitment: None,
362                         local_htlc_sigs: None,
363                         prev_local_commitment: None,
364                         prev_local_htlc_sigs: None,
365                         local_csv,
366                         key_storage,
367                         pending_claim_requests: HashMap::new(),
368                         claimable_outpoints: HashMap::new(),
369                         onchain_events_waiting_threshold_conf: HashMap::new(),
370
371                         secp_ctx: Secp256k1::new(),
372                         logger,
373                 }
374         }
375
376         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
377                 let mut tx_weight = 2; // count segwit flags
378                 for inp in inputs {
379                         // We use expected weight (and not actual) as signatures and time lock delays may vary
380                         tx_weight +=  match inp {
381                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
382                                 &InputDescriptors::RevokedOfferedHTLC => {
383                                         1 + 1 + 73 + 1 + 33 + 1 + 133
384                                 },
385                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
386                                 &InputDescriptors::RevokedReceivedHTLC => {
387                                         1 + 1 + 73 + 1 + 33 + 1 + 139
388                                 },
389                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
390                                 &InputDescriptors::OfferedHTLC => {
391                                         1 + 1 + 73 + 1 + 32 + 1 + 133
392                                 },
393                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
394                                 &InputDescriptors::ReceivedHTLC => {
395                                         1 + 1 + 73 + 1 + 1 + 1 + 139
396                                 },
397                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
398                                 &InputDescriptors::RevokedOutput => {
399                                         1 + 1 + 73 + 1 + 1 + 1 + 77
400                                 },
401                         };
402                 }
403                 tx_weight
404         }
405
406         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
407         /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
408         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
409         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
410         /// frequency of the bump and so increase our bets of success.
411         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
412                 if timelock_expiration <= current_height + 3 {
413                         return current_height + 1
414                 } else if timelock_expiration - current_height <= 15 {
415                         return current_height + 3
416                 }
417                 current_height + 15
418         }
419
420         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
421         /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
422         fn generate_claim_tx<F: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
423                 where F::Target: FeeEstimator
424         {
425                 if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
426                 let mut inputs = Vec::new();
427                 for outp in cached_claim_datas.per_input_material.keys() {
428                         log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
429                         inputs.push(TxIn {
430                                 previous_output: *outp,
431                                 script_sig: Script::new(),
432                                 sequence: 0xfffffffd,
433                                 witness: Vec::new(),
434                         });
435                 }
436                 let mut bumped_tx = Transaction {
437                         version: 2,
438                         lock_time: 0,
439                         input: inputs,
440                         output: vec![TxOut {
441                                 script_pubkey: self.destination_script.clone(),
442                                 value: 0
443                         }],
444                 };
445
446                 macro_rules! RBF_bump {
447                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
448                                 {
449                                         let mut used_feerate;
450                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
451                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
452                                                 let mut value = $amount;
453                                                 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
454                                                         // Overflow check is done in subtract_high_prio_fee
455                                                         $amount - value
456                                                 } else {
457                                                         log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
458                                                         return None;
459                                                 }
460                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
461                                         } else {
462                                                 let fee = $old_feerate * $predicted_weight / 750;
463                                                 if $amount <= fee {
464                                                         log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
465                                                         return None;
466                                                 }
467                                                 fee
468                                         };
469
470                                         let previous_fee = $old_feerate * $predicted_weight / 1000;
471                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
472                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
473                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
474                                         //      * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
475                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
476                                                 new_fee + previous_fee + min_relay_fee - new_fee
477                                         } else {
478                                                 new_fee
479                                         };
480                                         Some((new_fee, new_fee * 1000 / $predicted_weight))
481                                 }
482                         }
483                 }
484
485                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
486                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
487                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
488                 let mut inputs_witnesses_weight = 0;
489                 let mut amt = 0;
490                 let mut dynamic_fee = true;
491                 for per_outp_material in cached_claim_datas.per_input_material.values() {
492                         match per_outp_material {
493                                 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
494                                         inputs_witnesses_weight += Self::get_witnesses_weight(if !is_htlc { &[InputDescriptors::RevokedOutput] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { &[InputDescriptors::RevokedOfferedHTLC] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { &[InputDescriptors::RevokedReceivedHTLC] } else { unreachable!() });
495                                         amt += *amount;
496                                 },
497                                 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
498                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
499                                         amt += *amount;
500                                 },
501                                 &InputMaterial::LocalHTLC { .. } => {
502                                         dynamic_fee = false;
503                                 },
504                                 &InputMaterial::Funding { .. } => {
505                                         dynamic_fee = false;
506                                 }
507                         }
508                 }
509                 if dynamic_fee {
510                         let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
511                         let mut new_feerate;
512                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
513                         if cached_claim_datas.feerate_previous != 0 {
514                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
515                                         // If new computed fee is superior at the whole claimable amount burn all in fees
516                                         if new_fee > amt {
517                                                 bumped_tx.output[0].value = 0;
518                                         } else {
519                                                 bumped_tx.output[0].value = amt - new_fee;
520                                         }
521                                         new_feerate = feerate;
522                                 } else { return None; }
523                         } else {
524                                 if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
525                                         bumped_tx.output[0].value = amt;
526                                 } else { return None; }
527                         }
528                         assert!(new_feerate != 0);
529
530                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
531                                 match per_outp_material {
532                                         &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
533                                                 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
534                                                 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
535                                                 let sig = self.secp_ctx.sign(&sighash, &key);
536                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
537                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
538                                                 if *is_htlc {
539                                                         bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
540                                                 } else {
541                                                         bumped_tx.input[i].witness.push(vec!(1));
542                                                 }
543                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
544                                                 log_trace!(self, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if !is_htlc { "to_local" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { "offered" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
545                                         },
546                                         &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
547                                                 if !preimage.is_some() { bumped_tx.lock_time = *locktime }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
548                                                 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
549                                                 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
550                                                 let sig = self.secp_ctx.sign(&sighash, &key);
551                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
552                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
553                                                 if let &Some(preimage) = preimage {
554                                                         bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
555                                                 } else {
556                                                         bumped_tx.input[i].witness.push(vec![]);
557                                                 }
558                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
559                                                 log_trace!(self, "Going to broadcast Claim Transaction {} claiming remote {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
560                                         },
561                                         _ => unreachable!()
562                                 }
563                         }
564                         log_trace!(self, "...with timer {}", new_timer.unwrap());
565                         assert!(predicted_weight >= bumped_tx.get_weight());
566                         return Some((new_timer, new_feerate, bumped_tx))
567                 } else {
568                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
569                                 match per_outp_material {
570                                         &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
571                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
572                                                 if let Some(htlc_tx) = htlc_tx {
573                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
574                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
575                                                         log_trace!(self, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
576                                                         return Some((None, feerate, htlc_tx));
577                                                 }
578                                                 return None;
579                                         },
580                                         &InputMaterial::Funding { ref funding_redeemscript } => {
581                                                 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
582                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
583                                                 log_trace!(self, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
584                                                 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
585                                         }
586                                         _ => unreachable!()
587                                 }
588                         }
589                 }
590                 None
591         }
592
593         pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F)
594                 where B::Target: BroadcasterInterface,
595                       F::Target: FeeEstimator
596         {
597                 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
598                 let mut new_claims = Vec::new();
599                 let mut aggregated_claim = HashMap::new();
600                 let mut aggregated_soonest = ::std::u32::MAX;
601
602                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
603                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
604                 for req in claimable_outpoints {
605                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
606                         if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
607                                 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
608                                 if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable
609                                         let mut single_input = HashMap::new();
610                                         single_input.insert(req.outpoint, req.witness_data);
611                                         new_claims.push((req.absolute_timelock, single_input));
612                                 } else {
613                                         aggregated_claim.insert(req.outpoint, req.witness_data);
614                                         if req.absolute_timelock < aggregated_soonest {
615                                                 aggregated_soonest = req.absolute_timelock;
616                                         }
617                                 }
618                         }
619                 }
620                 new_claims.push((aggregated_soonest, aggregated_claim));
621
622                 // Generate claim transactions and track them to bump if necessary at
623                 // height timer expiration (i.e in how many blocks we're going to take action).
624                 for (soonest_timelock, claim) in new_claims.drain(..) {
625                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
626                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
627                                 claim_material.height_timer = new_timer;
628                                 claim_material.feerate_previous = new_feerate;
629                                 let txid = tx.txid();
630                                 for k in claim_material.per_input_material.keys() {
631                                         log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
632                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
633                                 }
634                                 self.pending_claim_requests.insert(txid, claim_material);
635                                 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
636                                 broadcaster.broadcast_transaction(&tx);
637                         }
638                 }
639
640                 let mut bump_candidates = HashMap::new();
641                 for tx in txn_matched {
642                         // Scan all input to verify is one of the outpoint spent is of interest for us
643                         let mut claimed_outputs_material = Vec::new();
644                         for inp in &tx.input {
645                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
646                                         // If outpoint has claim request pending on it...
647                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
648                                                 //... we need to verify equality between transaction outpoints and claim request
649                                                 // outpoints to know if transaction is the original claim or a bumped one issued
650                                                 // by us.
651                                                 let mut set_equality = true;
652                                                 if claim_material.per_input_material.len() != tx.input.len() {
653                                                         set_equality = false;
654                                                 } else {
655                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
656                                                                 if *claim_inp != tx_inp.previous_output {
657                                                                         set_equality = false;
658                                                                 }
659                                                         }
660                                                 }
661
662                                                 macro_rules! clean_claim_request_after_safety_delay {
663                                                         () => {
664                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
665                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
666                                                                         hash_map::Entry::Occupied(mut entry) => {
667                                                                                 if !entry.get().contains(&new_event) {
668                                                                                         entry.get_mut().push(new_event);
669                                                                                 }
670                                                                         },
671                                                                         hash_map::Entry::Vacant(entry) => {
672                                                                                 entry.insert(vec![new_event]);
673                                                                         }
674                                                                 }
675                                                         }
676                                                 }
677
678                                                 // If this is our transaction (or our counterparty spent all the outputs
679                                                 // before we could anyway with same inputs order than us), wait for
680                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
681                                                 if set_equality {
682                                                         clean_claim_request_after_safety_delay!();
683                                                 } else { // If false, generate new claim request with update outpoint set
684                                                         let mut at_least_one_drop = false;
685                                                         for input in tx.input.iter() {
686                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
687                                                                         claimed_outputs_material.push((input.previous_output, input_material));
688                                                                         at_least_one_drop = true;
689                                                                 }
690                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
691                                                                 if claim_material.per_input_material.is_empty() {
692                                                                         clean_claim_request_after_safety_delay!();
693                                                                 }
694                                                         }
695                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
696                                                         if at_least_one_drop {
697                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
698                                                         }
699                                                 }
700                                                 break; //No need to iterate further, either tx is our or their
701                                         } else {
702                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
703                                         }
704                                 }
705                         }
706                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
707                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
708                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
709                                         hash_map::Entry::Occupied(mut entry) => {
710                                                 if !entry.get().contains(&new_event) {
711                                                         entry.get_mut().push(new_event);
712                                                 }
713                                         },
714                                         hash_map::Entry::Vacant(entry) => {
715                                                 entry.insert(vec![new_event]);
716                                         }
717                                 }
718                         }
719                 }
720
721                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
722                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
723                         for ev in events {
724                                 match ev {
725                                         OnchainEvent::Claim { claim_request } => {
726                                                 // We may remove a whole set of claim outpoints here, as these one may have
727                                                 // been aggregated in a single tx and claimed so atomically
728                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
729                                                         for outpoint in bump_material.per_input_material.keys() {
730                                                                 self.claimable_outpoints.remove(&outpoint);
731                                                         }
732                                                 }
733                                         },
734                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
735                                                 self.claimable_outpoints.remove(&outpoint);
736                                         }
737                                 }
738                         }
739                 }
740
741                 // Check if any pending claim request must be rescheduled
742                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
743                         if let Some(h) = claim_data.height_timer {
744                                 if h == height {
745                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
746                                 }
747                         }
748                 }
749
750                 // Build, bump and rebroadcast tx accordingly
751                 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
752                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
753                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
754                                 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
755                                 broadcaster.broadcast_transaction(&bump_tx);
756                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
757                                         claim_material.height_timer = new_timer;
758                                         claim_material.feerate_previous = new_feerate;
759                                 }
760                         }
761                 }
762         }
763
764         pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
765                 where B::Target: BroadcasterInterface,
766                       F::Target: FeeEstimator
767         {
768                 let mut bump_candidates = HashMap::new();
769                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
770                         //- our claim tx on a commitment tx output
771                         //- resurect outpoint back in its claimable set and regenerate tx
772                         for ev in events {
773                                 match ev {
774                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
775                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
776                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
777                                                                 claim_material.per_input_material.insert(outpoint, input_material);
778                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
779                                                                 // resurrected only one bump claim tx is going to be broadcast
780                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
781                                                         }
782                                                 }
783                                         },
784                                         _ => {},
785                                 }
786                         }
787                 }
788                 for (_, claim_material) in bump_candidates.iter_mut() {
789                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
790                                 claim_material.height_timer = new_timer;
791                                 claim_material.feerate_previous = new_feerate;
792                                 broadcaster.broadcast_transaction(&bump_tx);
793                         }
794                 }
795                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
796                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
797                 }
798                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
799                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
800                 let mut remove_request = Vec::new();
801                 self.claimable_outpoints.retain(|_, ref v|
802                         if v.1 == height {
803                         remove_request.push(v.0.clone());
804                         false
805                         } else { true });
806                 for req in remove_request {
807                         self.pending_claim_requests.remove(&req);
808                 }
809         }
810
811         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
812                 // To prevent any unsafe state discrepancy between offchain and onchain, once local
813                 // commitment transaction has been signed due to an event (either block height for
814                 // HTLC-timeout or channel force-closure), don't allow any further update of local
815                 // commitment transaction view to avoid delivery of revocation secret to counterparty
816                 // for the aformentionned signed transaction.
817                 if let Some(ref local_commitment) = self.local_commitment {
818                         if local_commitment.has_local_sig() { return Err(()) }
819                 }
820                 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
821                         return Err(());
822                 }
823                 self.prev_local_commitment = self.local_commitment.take();
824                 self.local_commitment = Some(tx);
825                 Ok(())
826         }
827
828         fn sign_latest_local_htlcs(&mut self) {
829                 if let Some(ref local_commitment) = self.local_commitment {
830                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
831                                 self.local_htlc_sigs = Some(Vec::new());
832                                 let ret = self.local_htlc_sigs.as_mut().unwrap();
833                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
834                                         if let Some(tx_idx) = htlc.transaction_output_index {
835                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
836                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
837                                         } else {
838                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
839                                         }
840                                 }
841                         }
842                 }
843         }
844         fn sign_prev_local_htlcs(&mut self) {
845                 if let Some(ref local_commitment) = self.prev_local_commitment {
846                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
847                                 self.prev_local_htlc_sigs = Some(Vec::new());
848                                 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
849                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
850                                         if let Some(tx_idx) = htlc.transaction_output_index {
851                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
852                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
853                                         } else {
854                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
855                                         }
856                                 }
857                         }
858                 }
859         }
860
861         //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
862         // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
863         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
864         // to monitor before.
865         pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
866                 if let Some(ref mut local_commitment) = self.local_commitment {
867                         match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
868                                 Ok(sig) => local_commitment.add_local_sig(funding_redeemscript, sig),
869                                 Err(_) => return None,
870                         }
871                         return Some(local_commitment.with_valid_witness().clone());
872                 }
873                 None
874         }
875
876         #[cfg(test)]
877         pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
878                 if let Some(ref mut local_commitment) = self.local_commitment {
879                         let mut local_commitment = local_commitment.clone();
880                         match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
881                                 Ok(sig) => local_commitment.add_local_sig(funding_redeemscript, sig),
882                                 Err(_) => return None,
883                         }
884                         return Some(local_commitment.with_valid_witness().clone());
885                 }
886                 None
887         }
888
889         pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
890                 let mut htlc_tx = None;
891                 if self.local_commitment.is_some() {
892                         let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
893                         if commitment_txid == outp.txid {
894                                 self.sign_latest_local_htlcs();
895                                 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
896                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
897                                         htlc_tx = Some(self.local_commitment.as_ref().unwrap()
898                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
899                                 }
900                         }
901                 }
902                 if self.prev_local_commitment.is_some() {
903                         let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
904                         if commitment_txid == outp.txid {
905                                 self.sign_prev_local_htlcs();
906                                 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
907                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
908                                         htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
909                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
910                                 }
911                         }
912                 }
913                 htlc_tx
914         }
915
916         #[cfg(test)]
917         pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
918                 let latest_had_sigs = self.local_htlc_sigs.is_some();
919                 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
920                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
921                 if !latest_had_sigs {
922                         self.local_htlc_sigs = None;
923                 }
924                 if !prev_had_sigs {
925                         self.prev_local_htlc_sigs = None;
926                 }
927                 ret
928         }
929 }