1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 use crate::io_extras::sink;
11 use crate::prelude::*;
14 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
15 use bitcoin::consensus::Encodable;
16 use bitcoin::policy::MAX_STANDARD_TX_WEIGHT;
18 absolute::LockTime as AbsoluteLockTime, OutPoint, Sequence, Transaction, TxIn, TxOut,
21 use crate::chain::chaininterface::fee_for_weight;
22 use crate::events::bump_transaction::{BASE_INPUT_WEIGHT, EMPTY_SCRIPT_SIG_WEIGHT};
23 use crate::ln::channel::TOTAL_BITCOIN_SUPPLY_SATOSHIS;
24 use crate::ln::msgs::SerialId;
25 use crate::ln::{msgs, ChannelId};
26 use crate::sign::EntropySource;
27 use crate::util::ser::TransactionU16LenLimited;
29 /// The number of received `tx_add_input` messages during a negotiation at which point the
30 /// negotiation MUST be failed.
31 const MAX_RECEIVED_TX_ADD_INPUT_COUNT: u16 = 4096;
33 /// The number of received `tx_add_output` messages during a negotiation at which point the
34 /// negotiation MUST be failed.
35 const MAX_RECEIVED_TX_ADD_OUTPUT_COUNT: u16 = 4096;
37 /// The number of inputs or outputs that the state machine can have, before it MUST fail the
39 const MAX_INPUTS_OUTPUTS_COUNT: usize = 252;
42 fn is_for_initiator(&self) -> bool;
43 fn is_for_non_initiator(&self) -> bool;
46 impl SerialIdExt for SerialId {
47 fn is_for_initiator(&self) -> bool {
51 fn is_for_non_initiator(&self) -> bool {
52 !self.is_for_initiator()
56 #[derive(Debug, Clone, PartialEq)]
57 pub enum AbortReason {
58 InvalidStateTransition,
59 UnexpectedCounterpartyMessage,
60 ReceivedTooManyTxAddInputs,
61 ReceivedTooManyTxAddOutputs,
62 IncorrectInputSequenceValue,
63 IncorrectSerialIdParity,
67 ExceededMaximumSatsAllowed,
68 ExceededNumberOfInputsOrOutputs,
73 OutputsValueExceedsInputsValue,
78 pub struct TxInputWithPrevOutput {
84 struct NegotiationContext {
85 holder_is_initiator: bool,
86 received_tx_add_input_count: u16,
87 received_tx_add_output_count: u16,
88 inputs: HashMap<SerialId, TxInputWithPrevOutput>,
89 prevtx_outpoints: HashSet<OutPoint>,
90 outputs: HashMap<SerialId, TxOut>,
91 tx_locktime: AbsoluteLockTime,
92 feerate_sat_per_kw: u32,
95 impl NegotiationContext {
96 fn is_serial_id_valid_for_counterparty(&self, serial_id: &SerialId) -> bool {
97 // A received `SerialId`'s parity must match the role of the counterparty.
98 self.holder_is_initiator == serial_id.is_for_non_initiator()
101 fn total_input_and_output_count(&self) -> usize {
102 self.inputs.len().saturating_add(self.outputs.len())
105 fn counterparty_inputs_contributed(
107 ) -> impl Iterator<Item = &TxInputWithPrevOutput> + Clone {
110 .filter(move |(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
111 .map(|(_, input_with_prevout)| input_with_prevout)
114 fn counterparty_outputs_contributed(&self) -> impl Iterator<Item = &TxOut> + Clone {
117 .filter(move |(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
118 .map(|(_, output)| output)
121 fn received_tx_add_input(&mut self, msg: &msgs::TxAddInput) -> Result<(), AbortReason> {
122 // The interactive-txs spec calls for us to fail negotiation if the `prevtx` we receive is
123 // invalid. However, we would not need to account for this explicit negotiation failure
124 // mode here since `PeerManager` would already disconnect the peer if the `prevtx` is
125 // invalid; implicitly ending the negotiation.
127 if !self.is_serial_id_valid_for_counterparty(&msg.serial_id) {
128 // The receiving node:
129 // - MUST fail the negotiation if:
130 // - the `serial_id` has the wrong parity
131 return Err(AbortReason::IncorrectSerialIdParity);
134 self.received_tx_add_input_count += 1;
135 if self.received_tx_add_input_count > MAX_RECEIVED_TX_ADD_INPUT_COUNT {
136 // The receiving node:
137 // - MUST fail the negotiation if:
138 // - if has received 4096 `tx_add_input` messages during this negotiation
139 return Err(AbortReason::ReceivedTooManyTxAddInputs);
142 if msg.sequence >= 0xFFFFFFFE {
143 // The receiving node:
144 // - MUST fail the negotiation if:
145 // - `sequence` is set to `0xFFFFFFFE` or `0xFFFFFFFF`
146 return Err(AbortReason::IncorrectInputSequenceValue);
149 let transaction = msg.prevtx.as_transaction();
150 let txid = transaction.txid();
152 if let Some(tx_out) = transaction.output.get(msg.prevtx_out as usize) {
153 if !tx_out.script_pubkey.is_witness_program() {
154 // The receiving node:
155 // - MUST fail the negotiation if:
156 // - the `scriptPubKey` is not a witness program
157 return Err(AbortReason::PrevTxOutInvalid);
160 if !self.prevtx_outpoints.insert(OutPoint { txid, vout: msg.prevtx_out }) {
161 // The receiving node:
162 // - MUST fail the negotiation if:
163 // - the `prevtx` and `prevtx_vout` are identical to a previously added
164 // (and not removed) input's
165 return Err(AbortReason::PrevTxOutInvalid);
168 // The receiving node:
169 // - MUST fail the negotiation if:
170 // - `prevtx_vout` is greater or equal to the number of outputs on `prevtx`
171 return Err(AbortReason::PrevTxOutInvalid);
174 let prev_out = if let Some(prev_out) = transaction.output.get(msg.prevtx_out as usize) {
177 return Err(AbortReason::PrevTxOutInvalid);
179 match self.inputs.entry(msg.serial_id) {
180 hash_map::Entry::Occupied(_) => {
181 // The receiving node:
182 // - MUST fail the negotiation if:
183 // - the `serial_id` is already included in the transaction
184 Err(AbortReason::DuplicateSerialId)
186 hash_map::Entry::Vacant(entry) => {
187 let prev_outpoint = OutPoint { txid, vout: msg.prevtx_out };
188 entry.insert(TxInputWithPrevOutput {
190 previous_output: prev_outpoint,
191 sequence: Sequence(msg.sequence),
194 prev_output: prev_out,
196 self.prevtx_outpoints.insert(prev_outpoint);
202 fn received_tx_remove_input(&mut self, msg: &msgs::TxRemoveInput) -> Result<(), AbortReason> {
203 if !self.is_serial_id_valid_for_counterparty(&msg.serial_id) {
204 return Err(AbortReason::IncorrectSerialIdParity);
208 .remove(&msg.serial_id)
209 // The receiving node:
210 // - MUST fail the negotiation if:
211 // - the input or output identified by the `serial_id` was not added by the sender
212 // - the `serial_id` does not correspond to a currently added input
213 .ok_or(AbortReason::SerialIdUnknown)
217 fn received_tx_add_output(&mut self, msg: &msgs::TxAddOutput) -> Result<(), AbortReason> {
218 // The receiving node:
219 // - MUST fail the negotiation if:
220 // - the serial_id has the wrong parity
221 if !self.is_serial_id_valid_for_counterparty(&msg.serial_id) {
222 return Err(AbortReason::IncorrectSerialIdParity);
225 self.received_tx_add_output_count += 1;
226 if self.received_tx_add_output_count > MAX_RECEIVED_TX_ADD_OUTPUT_COUNT {
227 // The receiving node:
228 // - MUST fail the negotiation if:
229 // - if has received 4096 `tx_add_output` messages during this negotiation
230 return Err(AbortReason::ReceivedTooManyTxAddOutputs);
233 if msg.sats < msg.script.dust_value().to_sat() {
234 // The receiving node:
235 // - MUST fail the negotiation if:
236 // - the sats amount is less than the dust_limit
237 return Err(AbortReason::BelowDustLimit);
240 // Check that adding this output would not cause the total output value to exceed the total
242 let mut outputs_value: u64 = 0;
243 for output in self.outputs.iter() {
244 outputs_value = outputs_value.saturating_add(output.1.value);
246 if outputs_value.saturating_add(msg.sats) > TOTAL_BITCOIN_SUPPLY_SATOSHIS {
247 // The receiving node:
248 // - MUST fail the negotiation if:
249 // - the sats amount is greater than 2,100,000,000,000,000 (TOTAL_BITCOIN_SUPPLY_SATOSHIS)
250 return Err(AbortReason::ExceededMaximumSatsAllowed);
253 // The receiving node:
254 // - MUST accept P2WSH, P2WPKH, P2TR scripts
255 // - MAY fail the negotiation if script is non-standard
257 // We can actually be a bit looser than the above as only witness version 0 has special
258 // length-based standardness constraints to match similar consensus rules. All witness scripts
259 // with witness versions V1 and up are always considered standard. Yes, the scripts can be
260 // anyone-can-spend-able, but if our counterparty wants to add an output like that then it's none
261 // of our concern really ¯\_(ツ)_/¯
262 if !msg.script.is_v0_p2wpkh()
263 && !msg.script.is_v0_p2wsh()
264 && msg.script.witness_version().map(|v| v.to_num() < 1).unwrap_or(true)
266 return Err(AbortReason::InvalidOutputScript);
269 match self.outputs.entry(msg.serial_id) {
270 hash_map::Entry::Occupied(_) => {
271 // The receiving node:
272 // - MUST fail the negotiation if:
273 // - the `serial_id` is already included in the transaction
274 Err(AbortReason::DuplicateSerialId)
276 hash_map::Entry::Vacant(entry) => {
277 entry.insert(TxOut { value: msg.sats, script_pubkey: msg.script.clone() });
283 fn received_tx_remove_output(&mut self, msg: &msgs::TxRemoveOutput) -> Result<(), AbortReason> {
284 if !self.is_serial_id_valid_for_counterparty(&msg.serial_id) {
285 return Err(AbortReason::IncorrectSerialIdParity);
287 if self.outputs.remove(&msg.serial_id).is_some() {
290 // The receiving node:
291 // - MUST fail the negotiation if:
292 // - the input or output identified by the `serial_id` was not added by the sender
293 // - the `serial_id` does not correspond to a currently added input
294 Err(AbortReason::SerialIdUnknown)
298 fn sent_tx_add_input(&mut self, msg: &msgs::TxAddInput) {
299 let tx = msg.prevtx.as_transaction();
301 previous_output: OutPoint { txid: tx.txid(), vout: msg.prevtx_out },
302 sequence: Sequence(msg.sequence),
305 debug_assert!((msg.prevtx_out as usize) < tx.output.len());
306 let prev_output = &tx.output[msg.prevtx_out as usize];
307 self.prevtx_outpoints.insert(input.previous_output);
310 TxInputWithPrevOutput { input, prev_output: prev_output.clone() },
314 fn sent_tx_add_output(&mut self, msg: &msgs::TxAddOutput) {
316 .insert(msg.serial_id, TxOut { value: msg.sats, script_pubkey: msg.script.clone() });
319 fn sent_tx_remove_input(&mut self, msg: &msgs::TxRemoveInput) {
320 self.inputs.remove(&msg.serial_id);
323 fn sent_tx_remove_output(&mut self, msg: &msgs::TxRemoveOutput) {
324 self.outputs.remove(&msg.serial_id);
327 fn build_transaction(self) -> Result<Transaction, AbortReason> {
328 // The receiving node:
329 // MUST fail the negotiation if:
331 // - the peer's total input satoshis is less than their outputs
332 let mut counterparty_inputs_value: u64 = 0;
333 let mut counterparty_outputs_value: u64 = 0;
334 for input in self.counterparty_inputs_contributed() {
335 counterparty_inputs_value =
336 counterparty_inputs_value.saturating_add(input.prev_output.value);
338 for output in self.counterparty_outputs_contributed() {
339 counterparty_outputs_value = counterparty_outputs_value.saturating_add(output.value);
341 if counterparty_inputs_value < counterparty_outputs_value {
342 return Err(AbortReason::OutputsValueExceedsInputsValue);
345 // - there are more than 252 inputs
346 // - there are more than 252 outputs
347 if self.inputs.len() > MAX_INPUTS_OUTPUTS_COUNT
348 || self.outputs.len() > MAX_INPUTS_OUTPUTS_COUNT
350 return Err(AbortReason::ExceededNumberOfInputsOrOutputs);
353 // TODO: How do we enforce their fees cover the witness without knowing its expected length?
354 const INPUT_WEIGHT: u64 = BASE_INPUT_WEIGHT + EMPTY_SCRIPT_SIG_WEIGHT;
356 // - the peer's paid feerate does not meet or exceed the agreed feerate (based on the minimum fee).
357 let counterparty_output_weight_contributed: u64 = self
358 .counterparty_outputs_contributed()
360 (8 /* value */ + output.script_pubkey.consensus_encode(&mut sink()).unwrap() as u64)
361 * WITNESS_SCALE_FACTOR as u64
364 let counterparty_weight_contributed = counterparty_output_weight_contributed
365 + self.counterparty_inputs_contributed().count() as u64 * INPUT_WEIGHT;
366 let counterparty_fees_contributed =
367 counterparty_inputs_value.saturating_sub(counterparty_outputs_value);
368 let mut required_counterparty_contribution_fee =
369 fee_for_weight(self.feerate_sat_per_kw, counterparty_weight_contributed);
370 if !self.holder_is_initiator {
371 // if is the non-initiator:
372 // - the initiator's fees do not cover the common fields (version, segwit marker + flag,
373 // input count, output count, locktime)
374 let tx_common_fields_weight =
375 (4 /* version */ + 4 /* locktime */ + 1 /* input count */ + 1 /* output count */) *
376 WITNESS_SCALE_FACTOR as u64 + 2 /* segwit marker + flag */;
377 let tx_common_fields_fee =
378 fee_for_weight(self.feerate_sat_per_kw, tx_common_fields_weight);
379 required_counterparty_contribution_fee += tx_common_fields_fee;
381 if counterparty_fees_contributed < required_counterparty_contribution_fee {
382 return Err(AbortReason::InsufficientFees);
385 // Inputs and outputs must be sorted by serial_id
386 let mut inputs = self.inputs.into_iter().collect::<Vec<_>>();
387 let mut outputs = self.outputs.into_iter().collect::<Vec<_>>();
388 inputs.sort_unstable_by_key(|(serial_id, _)| *serial_id);
389 outputs.sort_unstable_by_key(|(serial_id, _)| *serial_id);
391 let tx_to_validate = Transaction {
393 lock_time: self.tx_locktime,
394 input: inputs.into_iter().map(|(_, input)| input.input).collect(),
395 output: outputs.into_iter().map(|(_, output)| output).collect(),
397 if tx_to_validate.weight().to_wu() > MAX_STANDARD_TX_WEIGHT as u64 {
398 return Err(AbortReason::TransactionTooLarge);
405 // The interactive transaction construction protocol allows two peers to collaboratively build a
406 // transaction for broadcast.
408 // The protocol is turn-based, so we define different states here that we store depending on whose
409 // turn it is to send the next message. The states are defined so that their types ensure we only
410 // perform actions (only send messages) via defined state transitions that do not violate the
413 // An example of a full negotiation and associated states follows:
415 // +------------+ +------------------+---- Holder state after message sent/received ----+
416 // | |--(1)- tx_add_input ---->| | SentChangeMsg +
417 // | |<-(2)- tx_complete ------| | ReceivedTxComplete +
418 // | |--(3)- tx_add_output --->| | SentChangeMsg +
419 // | |<-(4)- tx_complete ------| | ReceivedTxComplete +
420 // | |--(5)- tx_add_input ---->| | SentChangeMsg +
421 // | Holder |<-(6)- tx_add_input -----| Counterparty | ReceivedChangeMsg +
422 // | |--(7)- tx_remove_output >| | SentChangeMsg +
423 // | |<-(8)- tx_add_output ----| | ReceivedChangeMsg +
424 // | |--(9)- tx_complete ----->| | SentTxComplete +
425 // | |<-(10) tx_complete ------| | NegotiationComplete +
426 // +------------+ +------------------+--------------------------------------------------+
428 /// Negotiation states that can send & receive `tx_(add|remove)_(input|output)` and `tx_complete`
431 /// Category of states where we have sent some message to the counterparty, and we are waiting for
433 trait SentMsgState: State {
434 fn into_negotiation_context(self) -> NegotiationContext;
437 /// Category of states that our counterparty has put us in after we receive a message from them.
438 trait ReceivedMsgState: State {
439 fn into_negotiation_context(self) -> NegotiationContext;
442 // This macro is a helper for implementing the above state traits for various states subsequently
443 // defined below the macro.
444 macro_rules! define_state {
445 (SENT_MSG_STATE, $state: ident, $doc: expr) => {
446 define_state!($state, NegotiationContext, $doc);
447 impl SentMsgState for $state {
448 fn into_negotiation_context(self) -> NegotiationContext {
453 (RECEIVED_MSG_STATE, $state: ident, $doc: expr) => {
454 define_state!($state, NegotiationContext, $doc);
455 impl ReceivedMsgState for $state {
456 fn into_negotiation_context(self) -> NegotiationContext {
461 ($state: ident, $inner: ident, $doc: expr) => {
464 struct $state($inner);
465 impl State for $state {}
472 "We have sent a message to the counterparty that has affected our negotiation state."
477 "We have sent a `tx_complete` message and are awaiting the counterparty's."
482 "We have received a message from the counterparty that has affected our negotiation state."
487 "We have received a `tx_complete` message and the counterparty is awaiting ours."
489 define_state!(NegotiationComplete, Transaction, "We have exchanged consecutive `tx_complete` messages with the counterparty and the transaction negotiation is complete.");
493 "The negotiation has failed and cannot be continued."
496 type StateTransitionResult<S> = Result<S, AbortReason>;
498 trait StateTransition<NewState: State, TransitionData> {
499 fn transition(self, data: TransitionData) -> StateTransitionResult<NewState>;
502 // This macro helps define the legal transitions between the states above by implementing
503 // the `StateTransition` trait for each of the states that follow this declaration.
504 macro_rules! define_state_transitions {
505 (SENT_MSG_STATE, [$(DATA $data: ty, TRANSITION $transition: ident),+]) => {
507 impl<S: SentMsgState> StateTransition<ReceivedChangeMsg, $data> for S {
508 fn transition(self, data: $data) -> StateTransitionResult<ReceivedChangeMsg> {
509 let mut context = self.into_negotiation_context();
510 context.$transition(data)?;
511 Ok(ReceivedChangeMsg(context))
516 (RECEIVED_MSG_STATE, [$(DATA $data: ty, TRANSITION $transition: ident),+]) => {
518 impl<S: ReceivedMsgState> StateTransition<SentChangeMsg, $data> for S {
519 fn transition(self, data: $data) -> StateTransitionResult<SentChangeMsg> {
520 let mut context = self.into_negotiation_context();
521 context.$transition(data);
522 Ok(SentChangeMsg(context))
527 (TX_COMPLETE, $from_state: ident, $tx_complete_state: ident) => {
528 impl StateTransition<NegotiationComplete, &msgs::TxComplete> for $tx_complete_state {
529 fn transition(self, _data: &msgs::TxComplete) -> StateTransitionResult<NegotiationComplete> {
530 let context = self.into_negotiation_context();
531 let tx = context.build_transaction()?;
532 Ok(NegotiationComplete(tx))
536 impl StateTransition<$tx_complete_state, &msgs::TxComplete> for $from_state {
537 fn transition(self, _data: &msgs::TxComplete) -> StateTransitionResult<$tx_complete_state> {
538 Ok($tx_complete_state(self.into_negotiation_context()))
544 // State transitions when we have sent our counterparty some messages and are waiting for them
546 define_state_transitions!(SENT_MSG_STATE, [
547 DATA &msgs::TxAddInput, TRANSITION received_tx_add_input,
548 DATA &msgs::TxRemoveInput, TRANSITION received_tx_remove_input,
549 DATA &msgs::TxAddOutput, TRANSITION received_tx_add_output,
550 DATA &msgs::TxRemoveOutput, TRANSITION received_tx_remove_output
552 // State transitions when we have received some messages from our counterparty and we should
554 define_state_transitions!(RECEIVED_MSG_STATE, [
555 DATA &msgs::TxAddInput, TRANSITION sent_tx_add_input,
556 DATA &msgs::TxRemoveInput, TRANSITION sent_tx_remove_input,
557 DATA &msgs::TxAddOutput, TRANSITION sent_tx_add_output,
558 DATA &msgs::TxRemoveOutput, TRANSITION sent_tx_remove_output
560 define_state_transitions!(TX_COMPLETE, SentChangeMsg, ReceivedTxComplete);
561 define_state_transitions!(TX_COMPLETE, ReceivedChangeMsg, SentTxComplete);
566 SentChangeMsg(SentChangeMsg),
567 ReceivedChangeMsg(ReceivedChangeMsg),
568 SentTxComplete(SentTxComplete),
569 ReceivedTxComplete(ReceivedTxComplete),
570 NegotiationComplete(NegotiationComplete),
571 NegotiationAborted(NegotiationAborted),
574 impl Default for StateMachine {
575 fn default() -> Self {
580 // The `StateMachine` internally executes the actual transition between two states and keeps
581 // track of the current state. This macro defines _how_ those state transitions happen to
582 // update the internal state.
583 macro_rules! define_state_machine_transitions {
584 ($transition: ident, $msg: ty, [$(FROM $from_state: ident, TO $to_state: ident),+]) => {
585 fn $transition(self, msg: $msg) -> StateMachine {
588 Self::$from_state(s) => match s.transition(msg) {
589 Ok(new_state) => StateMachine::$to_state(new_state),
590 Err(abort_reason) => StateMachine::NegotiationAborted(NegotiationAborted(abort_reason)),
593 _ => StateMachine::NegotiationAborted(NegotiationAborted(AbortReason::UnexpectedCounterpartyMessage)),
600 fn new(feerate_sat_per_kw: u32, is_initiator: bool, tx_locktime: AbsoluteLockTime) -> Self {
601 let context = NegotiationContext {
603 holder_is_initiator: is_initiator,
604 received_tx_add_input_count: 0,
605 received_tx_add_output_count: 0,
606 inputs: new_hash_map(),
607 prevtx_outpoints: new_hash_set(),
608 outputs: new_hash_map(),
612 Self::ReceivedChangeMsg(ReceivedChangeMsg(context))
614 Self::SentChangeMsg(SentChangeMsg(context))
619 define_state_machine_transitions!(sent_tx_add_input, &msgs::TxAddInput, [
620 FROM ReceivedChangeMsg, TO SentChangeMsg,
621 FROM ReceivedTxComplete, TO SentChangeMsg
623 define_state_machine_transitions!(received_tx_add_input, &msgs::TxAddInput, [
624 FROM SentChangeMsg, TO ReceivedChangeMsg,
625 FROM SentTxComplete, TO ReceivedChangeMsg
629 define_state_machine_transitions!(sent_tx_add_output, &msgs::TxAddOutput, [
630 FROM ReceivedChangeMsg, TO SentChangeMsg,
631 FROM ReceivedTxComplete, TO SentChangeMsg
633 define_state_machine_transitions!(received_tx_add_output, &msgs::TxAddOutput, [
634 FROM SentChangeMsg, TO ReceivedChangeMsg,
635 FROM SentTxComplete, TO ReceivedChangeMsg
639 define_state_machine_transitions!(sent_tx_remove_input, &msgs::TxRemoveInput, [
640 FROM ReceivedChangeMsg, TO SentChangeMsg,
641 FROM ReceivedTxComplete, TO SentChangeMsg
643 define_state_machine_transitions!(received_tx_remove_input, &msgs::TxRemoveInput, [
644 FROM SentChangeMsg, TO ReceivedChangeMsg,
645 FROM SentTxComplete, TO ReceivedChangeMsg
649 define_state_machine_transitions!(sent_tx_remove_output, &msgs::TxRemoveOutput, [
650 FROM ReceivedChangeMsg, TO SentChangeMsg,
651 FROM ReceivedTxComplete, TO SentChangeMsg
653 define_state_machine_transitions!(received_tx_remove_output, &msgs::TxRemoveOutput, [
654 FROM SentChangeMsg, TO ReceivedChangeMsg,
655 FROM SentTxComplete, TO ReceivedChangeMsg
659 define_state_machine_transitions!(sent_tx_complete, &msgs::TxComplete, [
660 FROM ReceivedChangeMsg, TO SentTxComplete,
661 FROM ReceivedTxComplete, TO NegotiationComplete
663 define_state_machine_transitions!(received_tx_complete, &msgs::TxComplete, [
664 FROM SentChangeMsg, TO ReceivedTxComplete,
665 FROM SentTxComplete, TO NegotiationComplete
669 pub struct InteractiveTxConstructor {
670 state_machine: StateMachine,
671 channel_id: ChannelId,
672 inputs_to_contribute: Vec<(SerialId, TxIn, TransactionU16LenLimited)>,
673 outputs_to_contribute: Vec<(SerialId, TxOut)>,
676 pub enum InteractiveTxMessageSend {
677 TxAddInput(msgs::TxAddInput),
678 TxAddOutput(msgs::TxAddOutput),
679 TxComplete(msgs::TxComplete),
682 // This macro executes a state machine transition based on a provided action.
683 macro_rules! do_state_transition {
684 ($self: ident, $transition: ident, $msg: expr) => {{
685 let state_machine = core::mem::take(&mut $self.state_machine);
686 $self.state_machine = state_machine.$transition($msg);
687 match &$self.state_machine {
688 StateMachine::NegotiationAborted(state) => Err(state.0.clone()),
694 fn generate_holder_serial_id<ES: Deref>(entropy_source: &ES, is_initiator: bool) -> SerialId
696 ES::Target: EntropySource,
698 let rand_bytes = entropy_source.get_secure_random_bytes();
699 let mut serial_id_bytes = [0u8; 8];
700 serial_id_bytes.copy_from_slice(&rand_bytes[..8]);
701 let mut serial_id = u64::from_be_bytes(serial_id_bytes);
702 if serial_id.is_for_initiator() != is_initiator {
708 pub enum HandleTxCompleteValue {
709 SendTxMessage(InteractiveTxMessageSend),
710 SendTxComplete(InteractiveTxMessageSend, Transaction),
711 NegotiationComplete(Transaction),
714 impl InteractiveTxConstructor {
715 /// Instantiates a new `InteractiveTxConstructor`.
717 /// A tuple is returned containing the newly instantiate `InteractiveTxConstructor` and optionally
718 /// an initial wrapped `Tx_` message which the holder needs to send to the counterparty.
719 pub fn new<ES: Deref>(
720 entropy_source: &ES, channel_id: ChannelId, feerate_sat_per_kw: u32, is_initiator: bool,
721 funding_tx_locktime: AbsoluteLockTime,
722 inputs_to_contribute: Vec<(TxIn, TransactionU16LenLimited)>,
723 outputs_to_contribute: Vec<TxOut>,
724 ) -> (Self, Option<InteractiveTxMessageSend>)
726 ES::Target: EntropySource,
729 StateMachine::new(feerate_sat_per_kw, is_initiator, funding_tx_locktime);
730 let mut inputs_to_contribute: Vec<(SerialId, TxIn, TransactionU16LenLimited)> =
734 let serial_id = generate_holder_serial_id(entropy_source, is_initiator);
735 (serial_id, input, tx)
738 // We'll sort by the randomly generated serial IDs, effectively shuffling the order of the inputs
739 // as the user passed them to us to avoid leaking any potential categorization of transactions
740 // before we pass any of the inputs to the counterparty.
741 inputs_to_contribute.sort_unstable_by_key(|(serial_id, _, _)| *serial_id);
742 let mut outputs_to_contribute: Vec<(SerialId, TxOut)> = outputs_to_contribute
745 let serial_id = generate_holder_serial_id(entropy_source, is_initiator);
749 // In the same manner and for the same rationale as the inputs above, we'll shuffle the outputs.
750 outputs_to_contribute.sort_unstable_by_key(|(serial_id, _)| *serial_id);
751 let mut constructor =
752 Self { state_machine, channel_id, inputs_to_contribute, outputs_to_contribute };
753 let message_send = if is_initiator {
754 match constructor.maybe_send_message() {
755 Ok(msg_send) => Some(msg_send),
759 "We should always be able to start our state machine successfully"
767 (constructor, message_send)
770 fn maybe_send_message(&mut self) -> Result<InteractiveTxMessageSend, AbortReason> {
771 // We first attempt to send inputs we want to add, then outputs. Once we are done sending
772 // them both, then we always send tx_complete.
773 if let Some((serial_id, input, prevtx)) = self.inputs_to_contribute.pop() {
774 let msg = msgs::TxAddInput {
775 channel_id: self.channel_id,
778 prevtx_out: input.previous_output.vout,
779 sequence: input.sequence.to_consensus_u32(),
781 do_state_transition!(self, sent_tx_add_input, &msg)?;
782 Ok(InteractiveTxMessageSend::TxAddInput(msg))
783 } else if let Some((serial_id, output)) = self.outputs_to_contribute.pop() {
784 let msg = msgs::TxAddOutput {
785 channel_id: self.channel_id,
788 script: output.script_pubkey,
790 do_state_transition!(self, sent_tx_add_output, &msg)?;
791 Ok(InteractiveTxMessageSend::TxAddOutput(msg))
793 let msg = msgs::TxComplete { channel_id: self.channel_id };
794 do_state_transition!(self, sent_tx_complete, &msg)?;
795 Ok(InteractiveTxMessageSend::TxComplete(msg))
799 pub fn handle_tx_add_input(
800 &mut self, msg: &msgs::TxAddInput,
801 ) -> Result<InteractiveTxMessageSend, AbortReason> {
802 do_state_transition!(self, received_tx_add_input, msg)?;
803 self.maybe_send_message()
806 pub fn handle_tx_remove_input(
807 &mut self, msg: &msgs::TxRemoveInput,
808 ) -> Result<InteractiveTxMessageSend, AbortReason> {
809 do_state_transition!(self, received_tx_remove_input, msg)?;
810 self.maybe_send_message()
813 pub fn handle_tx_add_output(
814 &mut self, msg: &msgs::TxAddOutput,
815 ) -> Result<InteractiveTxMessageSend, AbortReason> {
816 do_state_transition!(self, received_tx_add_output, msg)?;
817 self.maybe_send_message()
820 pub fn handle_tx_remove_output(
821 &mut self, msg: &msgs::TxRemoveOutput,
822 ) -> Result<InteractiveTxMessageSend, AbortReason> {
823 do_state_transition!(self, received_tx_remove_output, msg)?;
824 self.maybe_send_message()
827 pub fn handle_tx_complete(
828 &mut self, msg: &msgs::TxComplete,
829 ) -> Result<HandleTxCompleteValue, AbortReason> {
830 do_state_transition!(self, received_tx_complete, msg)?;
831 match &self.state_machine {
832 StateMachine::ReceivedTxComplete(_) => {
833 let msg_send = self.maybe_send_message()?;
834 match &self.state_machine {
835 StateMachine::NegotiationComplete(s) => {
836 Ok(HandleTxCompleteValue::SendTxComplete(msg_send, s.0.clone()))
838 StateMachine::SentChangeMsg(_) => {
839 Ok(HandleTxCompleteValue::SendTxMessage(msg_send))
840 }, // We either had an input or output to contribute.
842 debug_assert!(false, "We cannot transition to any other states after receiving `tx_complete` and responding");
843 Err(AbortReason::InvalidStateTransition)
847 StateMachine::NegotiationComplete(s) => {
848 Ok(HandleTxCompleteValue::NegotiationComplete(s.0.clone()))
853 "We cannot transition to any other states after receiving `tx_complete`"
855 Err(AbortReason::InvalidStateTransition)
863 use crate::chain::chaininterface::FEERATE_FLOOR_SATS_PER_KW;
864 use crate::ln::channel::TOTAL_BITCOIN_SUPPLY_SATOSHIS;
865 use crate::ln::interactivetxs::{
866 generate_holder_serial_id, AbortReason, HandleTxCompleteValue, InteractiveTxConstructor,
867 InteractiveTxMessageSend, MAX_INPUTS_OUTPUTS_COUNT, MAX_RECEIVED_TX_ADD_INPUT_COUNT,
868 MAX_RECEIVED_TX_ADD_OUTPUT_COUNT,
870 use crate::ln::ChannelId;
871 use crate::sign::EntropySource;
872 use crate::util::atomic_counter::AtomicCounter;
873 use crate::util::ser::TransactionU16LenLimited;
874 use bitcoin::blockdata::opcodes;
875 use bitcoin::blockdata::script::Builder;
877 absolute::LockTime as AbsoluteLockTime, OutPoint, Sequence, Transaction, TxIn, TxOut,
879 use core::ops::Deref;
881 // A simple entropy source that works based on an atomic counter.
882 struct TestEntropySource(AtomicCounter);
883 impl EntropySource for TestEntropySource {
884 fn get_secure_random_bytes(&self) -> [u8; 32] {
885 let mut res = [0u8; 32];
886 let increment = self.0.get_increment();
888 // Rotate the increment value by 'i' bits to the right, to avoid clashes
889 // when `generate_local_serial_id` does a parity flip on consecutive calls for the
891 let rotated_increment = increment.rotate_right(i as u32);
892 res[i] = (rotated_increment & 0xff) as u8;
898 // An entropy source that deliberately returns you the same seed every time. We use this
899 // to test if the constructor would catch inputs/outputs that are attempting to be added
900 // with duplicate serial ids.
901 struct DuplicateEntropySource;
902 impl EntropySource for DuplicateEntropySource {
903 fn get_secure_random_bytes(&self) -> [u8; 32] {
904 let mut res = [0u8; 32];
906 res[0..8].copy_from_slice(&count.to_be_bytes());
911 #[derive(Debug, PartialEq, Eq)]
915 // Some error values are only checked at the end of the negotiation and are not easy to attribute
916 // to a particular party. Both parties would indicate an `AbortReason` in this case.
917 // e.g. Exceeded max inputs and outputs after negotiation.
922 inputs_a: Vec<(TxIn, TransactionU16LenLimited)>,
923 outputs_a: Vec<TxOut>,
924 inputs_b: Vec<(TxIn, TransactionU16LenLimited)>,
925 outputs_b: Vec<TxOut>,
926 expect_error: Option<(AbortReason, ErrorCulprit)>,
929 fn do_test_interactive_tx_constructor(session: TestSession) {
930 let entropy_source = TestEntropySource(AtomicCounter::new());
931 do_test_interactive_tx_constructor_internal(session, &&entropy_source);
934 fn do_test_interactive_tx_constructor_with_entropy_source<ES: Deref>(
935 session: TestSession, entropy_source: ES,
937 ES::Target: EntropySource,
939 do_test_interactive_tx_constructor_internal(session, &entropy_source);
942 fn do_test_interactive_tx_constructor_internal<ES: Deref>(
943 session: TestSession, entropy_source: &ES,
945 ES::Target: EntropySource,
947 let channel_id = ChannelId(entropy_source.get_secure_random_bytes());
948 let tx_locktime = AbsoluteLockTime::from_height(1337).unwrap();
950 let (mut constructor_a, first_message_a) = InteractiveTxConstructor::new(
953 FEERATE_FLOOR_SATS_PER_KW * 10,
959 let (mut constructor_b, first_message_b) = InteractiveTxConstructor::new(
962 FEERATE_FLOOR_SATS_PER_KW * 10,
969 let handle_message_send =
970 |msg: InteractiveTxMessageSend, for_constructor: &mut InteractiveTxConstructor| {
972 InteractiveTxMessageSend::TxAddInput(msg) => for_constructor
973 .handle_tx_add_input(&msg)
974 .map(|msg_send| (Some(msg_send), None)),
975 InteractiveTxMessageSend::TxAddOutput(msg) => for_constructor
976 .handle_tx_add_output(&msg)
977 .map(|msg_send| (Some(msg_send), None)),
978 InteractiveTxMessageSend::TxComplete(msg) => {
979 for_constructor.handle_tx_complete(&msg).map(|value| match value {
980 HandleTxCompleteValue::SendTxMessage(msg_send) => {
981 (Some(msg_send), None)
983 HandleTxCompleteValue::SendTxComplete(msg_send, tx) => {
984 (Some(msg_send), Some(tx))
986 HandleTxCompleteValue::NegotiationComplete(tx) => (None, Some(tx)),
992 assert!(first_message_b.is_none());
993 let mut message_send_a = first_message_a;
994 let mut message_send_b = None;
995 let mut final_tx_a = None;
996 let mut final_tx_b = None;
997 while final_tx_a.is_none() || final_tx_b.is_none() {
998 if let Some(message_send_a) = message_send_a.take() {
999 match handle_message_send(message_send_a, &mut constructor_b) {
1000 Ok((msg_send, final_tx)) => {
1001 message_send_b = msg_send;
1002 final_tx_b = final_tx;
1004 Err(abort_reason) => {
1005 let error_culprit = match abort_reason {
1006 AbortReason::ExceededNumberOfInputsOrOutputs => {
1007 ErrorCulprit::Indeterminate
1009 _ => ErrorCulprit::NodeA,
1011 assert_eq!(Some((abort_reason, error_culprit)), session.expect_error);
1012 assert!(message_send_b.is_none());
1017 if let Some(message_send_b) = message_send_b.take() {
1018 match handle_message_send(message_send_b, &mut constructor_a) {
1019 Ok((msg_send, final_tx)) => {
1020 message_send_a = msg_send;
1021 final_tx_a = final_tx;
1023 Err(abort_reason) => {
1024 let error_culprit = match abort_reason {
1025 AbortReason::ExceededNumberOfInputsOrOutputs => {
1026 ErrorCulprit::Indeterminate
1028 _ => ErrorCulprit::NodeB,
1030 assert_eq!(Some((abort_reason, error_culprit)), session.expect_error);
1031 assert!(message_send_a.is_none());
1037 assert!(message_send_a.is_none());
1038 assert!(message_send_b.is_none());
1039 assert_eq!(final_tx_a, final_tx_b);
1040 assert!(session.expect_error.is_none());
1043 fn generate_tx(values: &[u64]) -> Transaction {
1044 generate_tx_with_locktime(values, 1337)
1047 fn generate_tx_with_locktime(values: &[u64], locktime: u32) -> Transaction {
1050 lock_time: AbsoluteLockTime::from_height(locktime).unwrap(),
1051 input: vec![TxIn { ..Default::default() }],
1054 .map(|value| TxOut {
1056 script_pubkey: Builder::new()
1057 .push_opcode(opcodes::OP_TRUE)
1065 fn generate_inputs(values: &[u64]) -> Vec<(TxIn, TransactionU16LenLimited)> {
1066 let tx = generate_tx(values);
1067 let txid = tx.txid();
1073 previous_output: OutPoint { txid, vout: idx as u32 },
1074 script_sig: Default::default(),
1075 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1076 witness: Default::default(),
1078 (input, TransactionU16LenLimited::new(tx.clone()).unwrap())
1083 fn generate_outputs(values: &[u64]) -> Vec<TxOut> {
1086 .map(|value| TxOut {
1088 script_pubkey: Builder::new()
1089 .push_opcode(opcodes::OP_TRUE)
1096 fn generate_fixed_number_of_inputs(count: u16) -> Vec<(TxIn, TransactionU16LenLimited)> {
1097 // Generate transactions with a total `count` number of outputs such that no transaction has a
1098 // serialized length greater than u16::MAX.
1099 let max_outputs_per_prevtx = 1_500;
1100 let mut remaining = count;
1101 let mut inputs: Vec<(TxIn, TransactionU16LenLimited)> = Vec::with_capacity(count as usize);
1103 while remaining > 0 {
1104 let tx_output_count = remaining.min(max_outputs_per_prevtx);
1105 remaining -= tx_output_count;
1107 // Use unique locktime for each tx so outpoints are different across transactions
1108 let tx = generate_tx_with_locktime(
1109 &vec![1_000_000; tx_output_count as usize],
1110 (1337 + remaining).into(),
1112 let txid = tx.txid();
1114 let mut temp: Vec<(TxIn, TransactionU16LenLimited)> = tx
1120 previous_output: OutPoint { txid, vout: idx as u32 },
1121 script_sig: Default::default(),
1122 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1123 witness: Default::default(),
1125 (input, TransactionU16LenLimited::new(tx.clone()).unwrap())
1129 inputs.append(&mut temp);
1135 fn generate_fixed_number_of_outputs(count: u16) -> Vec<TxOut> {
1136 // Set a constant value for each TxOut
1137 generate_outputs(&vec![1_000_000; count as usize])
1140 fn generate_non_witness_output(value: u64) -> TxOut {
1143 script_pubkey: Builder::new().push_opcode(opcodes::OP_TRUE).into_script().to_p2sh(),
1148 fn test_interactive_tx_constructor() {
1149 // No contributions.
1150 do_test_interactive_tx_constructor(TestSession {
1155 expect_error: Some((AbortReason::InsufficientFees, ErrorCulprit::NodeA)),
1157 // Single contribution, no initiator inputs.
1158 do_test_interactive_tx_constructor(TestSession {
1160 outputs_a: generate_outputs(&[1_000_000]),
1163 expect_error: Some((AbortReason::OutputsValueExceedsInputsValue, ErrorCulprit::NodeA)),
1165 // Single contribution, no initiator outputs.
1166 do_test_interactive_tx_constructor(TestSession {
1167 inputs_a: generate_inputs(&[1_000_000]),
1173 // Single contribution, insufficient fees.
1174 do_test_interactive_tx_constructor(TestSession {
1175 inputs_a: generate_inputs(&[1_000_000]),
1176 outputs_a: generate_outputs(&[1_000_000]),
1179 expect_error: Some((AbortReason::InsufficientFees, ErrorCulprit::NodeA)),
1181 // Initiator contributes sufficient fees, but non-initiator does not.
1182 do_test_interactive_tx_constructor(TestSession {
1183 inputs_a: generate_inputs(&[1_000_000]),
1185 inputs_b: generate_inputs(&[100_000]),
1186 outputs_b: generate_outputs(&[100_000]),
1187 expect_error: Some((AbortReason::InsufficientFees, ErrorCulprit::NodeB)),
1189 // Multi-input-output contributions from both sides.
1190 do_test_interactive_tx_constructor(TestSession {
1191 inputs_a: generate_inputs(&[1_000_000, 1_000_000]),
1192 outputs_a: generate_outputs(&[1_000_000, 200_000]),
1193 inputs_b: generate_inputs(&[1_000_000, 500_000]),
1194 outputs_b: generate_outputs(&[1_000_000, 400_000]),
1198 // Prevout from initiator is not a witness program
1199 let non_segwit_output_tx = {
1200 let mut tx = generate_tx(&[1_000_000]);
1201 tx.output.push(TxOut {
1202 script_pubkey: Builder::new()
1203 .push_opcode(opcodes::all::OP_RETURN)
1206 ..Default::default()
1209 TransactionU16LenLimited::new(tx).unwrap()
1211 let non_segwit_input = TxIn {
1212 previous_output: OutPoint {
1213 txid: non_segwit_output_tx.as_transaction().txid(),
1216 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1217 ..Default::default()
1219 do_test_interactive_tx_constructor(TestSession {
1220 inputs_a: vec![(non_segwit_input, non_segwit_output_tx)],
1224 expect_error: Some((AbortReason::PrevTxOutInvalid, ErrorCulprit::NodeA)),
1227 // Invalid input sequence from initiator.
1228 let tx = TransactionU16LenLimited::new(generate_tx(&[1_000_000])).unwrap();
1229 let invalid_sequence_input = TxIn {
1230 previous_output: OutPoint { txid: tx.as_transaction().txid(), vout: 0 },
1231 ..Default::default()
1233 do_test_interactive_tx_constructor(TestSession {
1234 inputs_a: vec![(invalid_sequence_input, tx.clone())],
1235 outputs_a: generate_outputs(&[1_000_000]),
1238 expect_error: Some((AbortReason::IncorrectInputSequenceValue, ErrorCulprit::NodeA)),
1240 // Duplicate prevout from initiator.
1241 let duplicate_input = TxIn {
1242 previous_output: OutPoint { txid: tx.as_transaction().txid(), vout: 0 },
1243 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1244 ..Default::default()
1246 do_test_interactive_tx_constructor(TestSession {
1247 inputs_a: vec![(duplicate_input.clone(), tx.clone()), (duplicate_input, tx.clone())],
1248 outputs_a: generate_outputs(&[1_000_000]),
1251 expect_error: Some((AbortReason::PrevTxOutInvalid, ErrorCulprit::NodeA)),
1253 // Non-initiator uses same prevout as initiator.
1254 let duplicate_input = TxIn {
1255 previous_output: OutPoint { txid: tx.as_transaction().txid(), vout: 0 },
1256 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1257 ..Default::default()
1259 do_test_interactive_tx_constructor(TestSession {
1260 inputs_a: vec![(duplicate_input.clone(), tx.clone())],
1261 outputs_a: generate_outputs(&[1_000_000]),
1262 inputs_b: vec![(duplicate_input.clone(), tx.clone())],
1264 expect_error: Some((AbortReason::PrevTxOutInvalid, ErrorCulprit::NodeB)),
1266 // Initiator sends too many TxAddInputs
1267 do_test_interactive_tx_constructor(TestSession {
1268 inputs_a: generate_fixed_number_of_inputs(MAX_RECEIVED_TX_ADD_INPUT_COUNT + 1),
1272 expect_error: Some((AbortReason::ReceivedTooManyTxAddInputs, ErrorCulprit::NodeA)),
1274 // Attempt to queue up two inputs with duplicate serial ids. We use a deliberately bad
1275 // entropy source, `DuplicateEntropySource` to simulate this.
1276 do_test_interactive_tx_constructor_with_entropy_source(
1278 inputs_a: generate_fixed_number_of_inputs(2),
1282 expect_error: Some((AbortReason::DuplicateSerialId, ErrorCulprit::NodeA)),
1284 &DuplicateEntropySource,
1286 // Initiator sends too many TxAddOutputs.
1287 do_test_interactive_tx_constructor(TestSession {
1289 outputs_a: generate_fixed_number_of_outputs(MAX_RECEIVED_TX_ADD_OUTPUT_COUNT + 1),
1292 expect_error: Some((AbortReason::ReceivedTooManyTxAddOutputs, ErrorCulprit::NodeA)),
1294 // Initiator sends an output below dust value.
1295 do_test_interactive_tx_constructor(TestSession {
1297 outputs_a: generate_outputs(&[1]),
1300 expect_error: Some((AbortReason::BelowDustLimit, ErrorCulprit::NodeA)),
1302 // Initiator sends an output above maximum sats allowed.
1303 do_test_interactive_tx_constructor(TestSession {
1305 outputs_a: generate_outputs(&[TOTAL_BITCOIN_SUPPLY_SATOSHIS + 1]),
1308 expect_error: Some((AbortReason::ExceededMaximumSatsAllowed, ErrorCulprit::NodeA)),
1310 // Initiator sends an output without a witness program.
1311 do_test_interactive_tx_constructor(TestSession {
1313 outputs_a: vec![generate_non_witness_output(1_000_000)],
1316 expect_error: Some((AbortReason::InvalidOutputScript, ErrorCulprit::NodeA)),
1318 // Attempt to queue up two outputs with duplicate serial ids. We use a deliberately bad
1319 // entropy source, `DuplicateEntropySource` to simulate this.
1320 do_test_interactive_tx_constructor_with_entropy_source(
1323 outputs_a: generate_fixed_number_of_outputs(2),
1326 expect_error: Some((AbortReason::DuplicateSerialId, ErrorCulprit::NodeA)),
1328 &DuplicateEntropySource,
1331 // Peer contributed more output value than inputs
1332 do_test_interactive_tx_constructor(TestSession {
1333 inputs_a: generate_inputs(&[100_000]),
1334 outputs_a: generate_outputs(&[1_000_000]),
1337 expect_error: Some((AbortReason::OutputsValueExceedsInputsValue, ErrorCulprit::NodeA)),
1340 // Peer contributed more than allowed number of inputs.
1341 do_test_interactive_tx_constructor(TestSession {
1342 inputs_a: generate_fixed_number_of_inputs(MAX_INPUTS_OUTPUTS_COUNT as u16 + 1),
1346 expect_error: Some((
1347 AbortReason::ExceededNumberOfInputsOrOutputs,
1348 ErrorCulprit::Indeterminate,
1351 // Peer contributed more than allowed number of outputs.
1352 do_test_interactive_tx_constructor(TestSession {
1353 inputs_a: generate_inputs(&[TOTAL_BITCOIN_SUPPLY_SATOSHIS]),
1354 outputs_a: generate_fixed_number_of_outputs(MAX_INPUTS_OUTPUTS_COUNT as u16 + 1),
1357 expect_error: Some((
1358 AbortReason::ExceededNumberOfInputsOrOutputs,
1359 ErrorCulprit::Indeterminate,
1365 fn test_generate_local_serial_id() {
1366 let entropy_source = TestEntropySource(AtomicCounter::new());
1368 // Initiators should have even serial id, non-initiators should have odd serial id.
1369 assert_eq!(generate_holder_serial_id(&&entropy_source, true) % 2, 0);
1370 assert_eq!(generate_holder_serial_id(&&entropy_source, false) % 2, 1)