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 //! Provides keys to LDK and defines some useful objects describing spendable on-chain outputs.
12 //! The provided output descriptors follow a custom LDK data format and are currently not fully
13 //! compatible with Bitcoin Core output descriptors.
15 use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, EcdsaSighashType};
16 use bitcoin::blockdata::script::{Script, Builder};
17 use bitcoin::blockdata::opcodes;
18 use bitcoin::network::constants::Network;
19 use bitcoin::psbt::PartiallySignedTransaction;
20 use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
21 use bitcoin::util::sighash;
23 use bitcoin::bech32::u5;
24 use bitcoin::hashes::{Hash, HashEngine};
25 use bitcoin::hashes::sha256::Hash as Sha256;
26 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
27 use bitcoin::hash_types::WPubkeyHash;
29 use bitcoin::secp256k1::{KeyPair, PublicKey, Scalar, Secp256k1, SecretKey, Signing};
30 use bitcoin::secp256k1::ecdh::SharedSecret;
31 use bitcoin::secp256k1::ecdsa::{RecoverableSignature, Signature};
32 use bitcoin::secp256k1::schnorr;
33 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness, Txid};
35 use crate::util::transaction_utils;
36 use crate::util::crypto::{hkdf_extract_expand_twice, sign, sign_with_aux_rand};
37 use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
38 use crate::chain::transaction::OutPoint;
39 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
40 use crate::ln::{chan_utils, PaymentPreimage};
41 use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
42 use crate::ln::msgs::{UnsignedChannelAnnouncement, UnsignedGossipMessage};
43 use crate::ln::script::ShutdownScript;
44 use crate::offers::invoice::UnsignedBolt12Invoice;
45 use crate::offers::invoice_request::UnsignedInvoiceRequest;
47 use crate::prelude::*;
48 use core::convert::TryInto;
50 use core::sync::atomic::{AtomicUsize, Ordering};
51 use crate::io::{self, Error};
52 use crate::ln::features::ChannelTypeFeatures;
53 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
54 use crate::util::atomic_counter::AtomicCounter;
55 use crate::util::chacha20::ChaCha20;
56 use crate::util::invoice::construct_invoice_preimage;
58 pub(crate) mod type_resolver;
60 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
61 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
63 /// This is not exported to bindings users as we just use `[u8; 32]` directly
64 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
65 pub struct KeyMaterial(pub [u8; 32]);
67 /// Information about a spendable output to a P2WSH script.
69 /// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
70 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
71 pub struct DelayedPaymentOutputDescriptor {
72 /// The outpoint which is spendable.
73 pub outpoint: OutPoint,
74 /// Per commitment point to derive the delayed payment key by key holder.
75 pub per_commitment_point: PublicKey,
76 /// The `nSequence` value which must be set in the spending input to satisfy the `OP_CSV` in
77 /// the witness_script.
78 pub to_self_delay: u16,
79 /// The output which is referenced by the given outpoint.
81 /// The revocation point specific to the commitment transaction which was broadcast. Used to
82 /// derive the witnessScript for this output.
83 pub revocation_pubkey: PublicKey,
84 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
85 /// This may be useful in re-deriving keys used in the channel to spend the output.
86 pub channel_keys_id: [u8; 32],
87 /// The value of the channel which this output originated from, possibly indirectly.
88 pub channel_value_satoshis: u64,
90 impl DelayedPaymentOutputDescriptor {
91 /// The maximum length a well-formed witness spending one of these should have.
92 /// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
94 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
95 // redeemscript push length.
96 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
99 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
100 (0, outpoint, required),
101 (2, per_commitment_point, required),
102 (4, to_self_delay, required),
103 (6, output, required),
104 (8, revocation_pubkey, required),
105 (10, channel_keys_id, required),
106 (12, channel_value_satoshis, required),
109 pub(crate) const P2WPKH_WITNESS_WEIGHT: u64 = 1 /* num stack items */ +
111 73 /* sig including sighash flag */ +
112 1 /* pubkey length */ +
115 /// Information about a spendable output to our "payment key".
117 /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
118 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
119 pub struct StaticPaymentOutputDescriptor {
120 /// The outpoint which is spendable.
121 pub outpoint: OutPoint,
122 /// The output which is referenced by the given outpoint.
124 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
125 /// This may be useful in re-deriving keys used in the channel to spend the output.
126 pub channel_keys_id: [u8; 32],
127 /// The value of the channel which this transactions spends.
128 pub channel_value_satoshis: u64,
129 /// The necessary channel parameters that need to be provided to the re-derived signer through
130 /// [`ChannelSigner::provide_channel_parameters`].
132 /// Added as optional, but always `Some` if the descriptor was produced in v0.0.117 or later.
133 pub channel_transaction_parameters: Option<ChannelTransactionParameters>,
135 impl StaticPaymentOutputDescriptor {
136 /// Returns the `witness_script` of the spendable output.
138 /// Note that this will only return `Some` for [`StaticPaymentOutputDescriptor`]s that
139 /// originated from an anchor outputs channel, as they take the form of a P2WSH script.
140 pub fn witness_script(&self) -> Option<Script> {
141 self.channel_transaction_parameters.as_ref()
142 .and_then(|channel_params|
143 if channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
144 let payment_point = channel_params.holder_pubkeys.payment_point;
145 Some(chan_utils::get_to_countersignatory_with_anchors_redeemscript(&payment_point))
152 /// The maximum length a well-formed witness spending one of these should have.
153 /// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
155 pub fn max_witness_length(&self) -> usize {
156 if self.channel_transaction_parameters.as_ref()
157 .map(|channel_params| channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx())
160 let witness_script_weight = 1 /* pubkey push */ + 33 /* pubkey */ +
161 1 /* OP_CHECKSIGVERIFY */ + 1 /* OP_1 */ + 1 /* OP_CHECKSEQUENCEVERIFY */;
162 1 /* num witness items */ + 1 /* sig push */ + 73 /* sig including sighash flag */ +
163 1 /* witness script push */ + witness_script_weight
165 P2WPKH_WITNESS_WEIGHT as usize
169 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
170 (0, outpoint, required),
171 (2, output, required),
172 (4, channel_keys_id, required),
173 (6, channel_value_satoshis, required),
174 (7, channel_transaction_parameters, option),
177 /// Describes the necessary information to spend a spendable output.
179 /// When on-chain outputs are created by LDK (which our counterparty is not able to claim at any
180 /// point in the future) a [`SpendableOutputs`] event is generated which you must track and be able
181 /// to spend on-chain. The information needed to do this is provided in this enum, including the
182 /// outpoint describing which `txid` and output `index` is available, the full output which exists
183 /// at that `txid`/`index`, and any keys or other information required to sign.
185 /// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
186 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
187 pub enum SpendableOutputDescriptor {
188 /// An output to a script which was provided via [`SignerProvider`] directly, either from
189 /// [`get_destination_script`] or [`get_shutdown_scriptpubkey`], thus you should already
190 /// know how to spend it. No secret keys are provided as LDK was never given any key.
191 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
192 /// on-chain using the payment preimage or after it has timed out.
194 /// [`get_shutdown_scriptpubkey`]: SignerProvider::get_shutdown_scriptpubkey
195 /// [`get_destination_script`]: SignerProvider::get_shutdown_scriptpubkey
197 /// The outpoint which is spendable.
199 /// The output which is referenced by the given outpoint.
202 /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
205 /// The witness in the spending input should be:
207 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
210 /// Note that the `nSequence` field in the spending input must be set to
211 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
212 /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
213 /// the outpoint confirms, see [BIP
214 /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
215 /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
218 /// These are generally the result of a "revocable" output to us, spendable only by us unless
219 /// it is an output from an old state which we broadcast (which should never happen).
221 /// To derive the delayed payment key which is used to sign this input, you must pass the
222 /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the
223 /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`ChannelSigner::pubkeys`]) and the provided
224 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The public key can be
225 /// generated without the secret key using [`chan_utils::derive_public_key`] and only the
226 /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`].
228 /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
229 /// used in the witness script generation), you must pass the counterparty
230 /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to
231 /// [`ChannelSigner::provide_channel_parameters`]) and the provided
232 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to
233 /// [`chan_utils::derive_public_revocation_key`].
235 /// The witness script which is hashed and included in the output `script_pubkey` may be
236 /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
237 /// as explained above), our delayed payment pubkey (derived as explained above), and the
238 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to
239 /// [`chan_utils::get_revokeable_redeemscript`].
240 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
241 /// An output spendable exclusively by our payment key (i.e., the private key that corresponds
242 /// to the `payment_point` in [`ChannelSigner::pubkeys`]). The output type depends on the
243 /// channel type negotiated.
245 /// On an anchor outputs channel, the witness in the spending input is:
247 /// <BIP 143 signature> <witness script>
250 /// Otherwise, it is:
252 /// <BIP 143 signature> <payment key>
255 /// These are generally the result of our counterparty having broadcast the current state,
256 /// allowing us to claim the non-HTLC-encumbered outputs immediately, or after one confirmation
257 /// in the case of anchor outputs channels.
258 StaticPaymentOutput(StaticPaymentOutputDescriptor),
261 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
262 (0, StaticOutput) => {
263 (0, outpoint, required),
264 (2, output, required),
267 (1, DelayedPaymentOutput),
268 (2, StaticPaymentOutput),
271 impl SpendableOutputDescriptor {
272 /// Turns this into a [`bitcoin::psbt::Input`] which can be used to create a
273 /// [`PartiallySignedTransaction`] which spends the given descriptor.
275 /// Note that this does not include any signatures, just the information required to
276 /// construct the transaction and sign it.
278 /// This is not exported to bindings users as there is no standard serialization for an input.
279 /// See [`Self::create_spendable_outputs_psbt`] instead.
280 pub fn to_psbt_input(&self) -> bitcoin::psbt::Input {
282 SpendableOutputDescriptor::StaticOutput { output, .. } => {
283 // Is a standard P2WPKH, no need for witness script
284 bitcoin::psbt::Input {
285 witness_utxo: Some(output.clone()),
289 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
290 // TODO we could add the witness script as well
291 bitcoin::psbt::Input {
292 witness_utxo: Some(descriptor.output.clone()),
296 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
297 // TODO we could add the witness script as well
298 bitcoin::psbt::Input {
299 witness_utxo: Some(descriptor.output.clone()),
306 /// Creates an unsigned [`PartiallySignedTransaction`] which spends the given descriptors to
307 /// the given outputs, plus an output to the given change destination (if sufficient
308 /// change value remains). The PSBT will have a feerate, at least, of the given value.
310 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
311 /// transaction will have a locktime of 0. It it recommended to set this to the current block
312 /// height to avoid fee sniping, unless you have some specific reason to use a different
315 /// Returns the PSBT and expected max transaction weight.
317 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
318 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
319 /// does not match the one we can spend.
321 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
322 pub fn create_spendable_outputs_psbt(descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option<PackedLockTime>) -> Result<(PartiallySignedTransaction, usize), ()> {
323 let mut input = Vec::with_capacity(descriptors.len());
324 let mut input_value = 0;
325 let mut witness_weight = 0;
326 let mut output_set = HashSet::with_capacity(descriptors.len());
327 for outp in descriptors {
329 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
330 if !output_set.insert(descriptor.outpoint) { return Err(()); }
332 if descriptor.channel_transaction_parameters.as_ref()
333 .map(|channel_params| channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx())
336 Sequence::from_consensus(1)
341 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
342 script_sig: Script::new(),
344 witness: Witness::new(),
346 witness_weight += descriptor.max_witness_length();
347 #[cfg(feature = "grind_signatures")]
348 { witness_weight -= 1; } // Guarantees a low R signature
349 input_value += descriptor.output.value;
351 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
352 if !output_set.insert(descriptor.outpoint) { return Err(()); }
354 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
355 script_sig: Script::new(),
356 sequence: Sequence(descriptor.to_self_delay as u32),
357 witness: Witness::new(),
359 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
360 #[cfg(feature = "grind_signatures")]
361 { witness_weight -= 1; } // Guarantees a low R signature
362 input_value += descriptor.output.value;
364 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
365 if !output_set.insert(*outpoint) { return Err(()); }
367 previous_output: outpoint.into_bitcoin_outpoint(),
368 script_sig: Script::new(),
369 sequence: Sequence::ZERO,
370 witness: Witness::new(),
372 witness_weight += 1 + 73 + 34;
373 #[cfg(feature = "grind_signatures")]
374 { witness_weight -= 1; } // Guarantees a low R signature
375 input_value += output.value;
378 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
380 let mut tx = Transaction {
382 lock_time: locktime.unwrap_or(PackedLockTime::ZERO),
386 let expected_max_weight =
387 transaction_utils::maybe_add_change_output(&mut tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
389 let psbt_inputs = descriptors.iter().map(|d| d.to_psbt_input()).collect::<Vec<_>>();
390 let psbt = PartiallySignedTransaction {
392 outputs: vec![Default::default(); tx.output.len()],
394 xpub: Default::default(),
396 proprietary: Default::default(),
397 unknown: Default::default(),
399 Ok((psbt, expected_max_weight))
403 /// The parameters required to derive a channel signer via [`SignerProvider`].
404 #[derive(Clone, Debug, PartialEq, Eq)]
405 pub struct ChannelDerivationParameters {
406 /// The value in satoshis of the channel we're attempting to spend the anchor output of.
407 pub value_satoshis: u64,
408 /// The unique identifier to re-derive the signer for the associated channel.
409 pub keys_id: [u8; 32],
410 /// The necessary channel parameters that need to be provided to the re-derived signer through
411 /// [`ChannelSigner::provide_channel_parameters`].
412 pub transaction_parameters: ChannelTransactionParameters,
415 impl_writeable_tlv_based!(ChannelDerivationParameters, {
416 (0, value_satoshis, required),
417 (2, keys_id, required),
418 (4, transaction_parameters, required),
421 /// A descriptor used to sign for a commitment transaction's HTLC output.
422 #[derive(Clone, Debug, PartialEq, Eq)]
423 pub struct HTLCDescriptor {
424 /// The parameters required to derive the signer for the HTLC input.
425 pub channel_derivation_parameters: ChannelDerivationParameters,
426 /// The txid of the commitment transaction in which the HTLC output lives.
427 pub commitment_txid: Txid,
428 /// The number of the commitment transaction in which the HTLC output lives.
429 pub per_commitment_number: u64,
430 /// The key tweak corresponding to the number of the commitment transaction in which the HTLC
431 /// output lives. This tweak is applied to all the basepoints for both parties in the channel to
432 /// arrive at unique keys per commitment.
434 /// See <https://github.com/lightning/bolts/blob/master/03-transactions.md#keys> for more info.
435 pub per_commitment_point: PublicKey,
436 /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs
437 /// originating from a channel supporting anchor outputs, otherwise it is the channel's
438 /// negotiated feerate at the time the commitment transaction was built.
439 pub feerate_per_kw: u32,
440 /// The details of the HTLC as it appears in the commitment transaction.
441 pub htlc: HTLCOutputInCommitment,
442 /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be
444 pub preimage: Option<PaymentPreimage>,
445 /// The counterparty's signature required to spend the HTLC output.
446 pub counterparty_sig: Signature
449 impl_writeable_tlv_based!(HTLCDescriptor, {
450 (0, channel_derivation_parameters, required),
451 (1, feerate_per_kw, (default_value, 0)),
452 (2, commitment_txid, required),
453 (4, per_commitment_number, required),
454 (6, per_commitment_point, required),
456 (10, preimage, option),
457 (12, counterparty_sig, required),
460 impl HTLCDescriptor {
461 /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint
462 /// being spent by the HTLC input in the HTLC transaction.
463 pub fn outpoint(&self) -> bitcoin::OutPoint {
465 txid: self.commitment_txid,
466 vout: self.htlc.transaction_output_index.unwrap(),
470 /// Returns the UTXO to be spent by the HTLC input, which can be obtained via
471 /// [`Self::unsigned_tx_input`].
472 pub fn previous_utxo<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
474 script_pubkey: self.witness_script(secp).to_v0_p2wsh(),
475 value: self.htlc.amount_msat / 1000,
479 /// Returns the unsigned transaction input spending the HTLC output in the commitment
481 pub fn unsigned_tx_input(&self) -> TxIn {
482 chan_utils::build_htlc_input(
483 &self.commitment_txid, &self.htlc, &self.channel_derivation_parameters.transaction_parameters.channel_type_features
487 /// Returns the delayed output created as a result of spending the HTLC output in the commitment
489 pub fn tx_output<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
490 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
491 let broadcaster_keys = channel_params.broadcaster_pubkeys();
492 let counterparty_keys = channel_params.countersignatory_pubkeys();
493 let broadcaster_delayed_key = chan_utils::derive_public_key(
494 secp, &self.per_commitment_point, &broadcaster_keys.delayed_payment_basepoint
496 let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
497 secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint
499 chan_utils::build_htlc_output(
500 self.feerate_per_kw, channel_params.contest_delay(), &self.htlc,
501 channel_params.channel_type_features(), &broadcaster_delayed_key, &counterparty_revocation_key
505 /// Returns the witness script of the HTLC output in the commitment transaction.
506 pub fn witness_script<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> Script {
507 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
508 let broadcaster_keys = channel_params.broadcaster_pubkeys();
509 let counterparty_keys = channel_params.countersignatory_pubkeys();
510 let broadcaster_htlc_key = chan_utils::derive_public_key(
511 secp, &self.per_commitment_point, &broadcaster_keys.htlc_basepoint
513 let counterparty_htlc_key = chan_utils::derive_public_key(
514 secp, &self.per_commitment_point, &counterparty_keys.htlc_basepoint
516 let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
517 secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint
519 chan_utils::get_htlc_redeemscript_with_explicit_keys(
520 &self.htlc, channel_params.channel_type_features(), &broadcaster_htlc_key, &counterparty_htlc_key,
521 &counterparty_revocation_key,
525 /// Returns the fully signed witness required to spend the HTLC output in the commitment
527 pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness {
528 chan_utils::build_htlc_input_witness(
529 signature, &self.counterparty_sig, &self.preimage, witness_script,
530 &self.channel_derivation_parameters.transaction_parameters.channel_type_features
534 /// Derives the channel signer required to sign the HTLC input.
535 pub fn derive_channel_signer<S: WriteableEcdsaChannelSigner, SP: Deref>(&self, signer_provider: &SP) -> S
537 SP::Target: SignerProvider<Signer = S>
539 let mut signer = signer_provider.derive_channel_signer(
540 self.channel_derivation_parameters.value_satoshis,
541 self.channel_derivation_parameters.keys_id,
543 signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters);
548 /// A trait to handle Lightning channel key material without concretizing the channel type or
549 /// the signature mechanism.
550 pub trait ChannelSigner {
551 /// Gets the per-commitment point for a specific commitment number
553 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
554 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
556 /// Gets the commitment secret for a specific commitment number as part of the revocation process
558 /// An external signer implementation should error here if the commitment was already signed
559 /// and should refuse to sign it in the future.
561 /// May be called more than once for the same index.
563 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
564 // TODO: return a Result so we can signal a validation error
565 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
567 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
569 /// This is required in order for the signer to make sure that releasing a commitment
570 /// secret won't leave us without a broadcastable holder transaction.
571 /// Policy checks should be implemented in this function, including checking the amount
572 /// sent to us and checking the HTLCs.
574 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
575 /// A validating signer should ensure that an HTLC output is removed only when the matching
576 /// preimage is provided, or when the value to holder is restored.
578 /// Note that all the relevant preimages will be provided, but there may also be additional
579 /// irrelevant or duplicate preimages.
580 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
581 preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
583 /// Returns the holder's channel public keys and basepoints.
584 fn pubkeys(&self) -> &ChannelPublicKeys;
586 /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
587 /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
588 /// [`EcdsaChannelSigner`] object uniquely and lookup or re-derive its keys.
589 fn channel_keys_id(&self) -> [u8; 32];
591 /// Set the counterparty static channel data, including basepoints,
592 /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint.
594 /// This data is static, and will never change for a channel once set. For a given [`ChannelSigner`]
595 /// instance, LDK will call this method exactly once - either immediately after construction
596 /// (not including if done via [`SignerProvider::read_chan_signer`]) or when the funding
597 /// information has been generated.
599 /// channel_parameters.is_populated() MUST be true.
600 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
603 /// A trait to sign Lightning channel transactions as described in
604 /// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
606 /// Signing services could be implemented on a hardware wallet and should implement signing
607 /// policies in order to be secure. Please refer to the [VLS Policy
608 /// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md)
609 /// for an example of such policies.
610 pub trait EcdsaChannelSigner: ChannelSigner {
611 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
613 /// Note that if signing fails or is rejected, the channel will be force-closed.
615 /// Policy checks should be implemented in this function, including checking the amount
616 /// sent to us and checking the HTLCs.
618 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
619 /// A validating signer should ensure that an HTLC output is removed only when the matching
620 /// preimage is provided, or when the value to holder is restored.
622 /// Note that all the relevant preimages will be provided, but there may also be additional
623 /// irrelevant or duplicate preimages.
625 // TODO: Document the things someone using this interface should enforce before signing.
626 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
627 preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
628 ) -> Result<(Signature, Vec<Signature>), ()>;
629 /// Validate the counterparty's revocation.
631 /// This is required in order for the signer to make sure that the state has moved
632 /// forward and it is safe to sign the next counterparty commitment.
633 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
634 /// Creates a signature for a holder's commitment transaction.
636 /// This will be called
637 /// - with a non-revoked `commitment_tx`.
638 /// - with the latest `commitment_tx` when we initiate a force-close.
640 /// This may be called multiple times for the same transaction.
642 /// An external signer implementation should check that the commitment has not been revoked.
644 // TODO: Document the things someone using this interface should enforce before signing.
645 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
646 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
647 /// Same as [`sign_holder_commitment`], but exists only for tests to get access to holder
648 /// commitment transactions which will be broadcasted later, after the channel has moved on to a
649 /// newer state. Thus, needs its own method as [`sign_holder_commitment`] may enforce that we
650 /// only ever get called once.
651 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
652 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
653 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
654 /// Create a signature for the given input in a transaction spending an HTLC transaction output
655 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
657 /// A justice transaction may claim multiple outputs at the same time if timelocks are
658 /// similar, but only a signature for the input at index `input` should be signed for here.
659 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
660 /// to an upcoming timelock expiration.
662 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
664 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
665 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
666 /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do
668 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64,
669 per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>
670 ) -> Result<Signature, ()>;
671 /// Create a signature for the given input in a transaction spending a commitment transaction
672 /// HTLC output when our counterparty broadcasts an old state.
674 /// A justice transaction may claim multiple outputs at the same time if timelocks are
675 /// similar, but only a signature for the input at index `input` should be signed for here.
676 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
677 /// to an upcoming timelock expiration.
679 /// `amount` is the value of the output spent by this input, committed to in the BIP 143
682 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
683 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
684 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
687 /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script
688 /// (which is committed to in the BIP 143 signatures).
689 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64,
690 per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment,
691 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
692 /// Computes the signature for a commitment transaction's HTLC output used as an input within
693 /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned
694 /// must be be computed using [`EcdsaSighashType::All`].
696 /// Note that this may be called for HTLCs in the penultimate commitment transaction if a
697 /// [`ChannelMonitor`] [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas)
698 /// broadcasts it before receiving the update for the latest commitment transaction.
700 /// [`EcdsaSighashType::All`]: bitcoin::blockdata::transaction::EcdsaSighashType::All
701 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
702 fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize,
703 htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1<secp256k1::All>
704 ) -> Result<Signature, ()>;
705 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
706 /// transaction, either offered or received.
708 /// Such a transaction may claim multiples offered outputs at same time if we know the
709 /// preimage for each when we create it, but only the input at index `input` should be
710 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
711 /// needed with regards to an upcoming timelock expiration.
713 /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
716 /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
718 /// `per_commitment_point` is the dynamic point corresponding to the channel state
719 /// detected onchain. It has been generated by our counterparty and is used to derive
720 /// channel state keys, which are then included in the witness script and committed to in the
721 /// BIP 143 signature.
722 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64,
723 per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment,
724 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
725 /// Create a signature for a (proposed) closing transaction.
727 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
728 /// chosen to forgo their output as dust.
729 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
730 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
731 /// Computes the signature for a commitment transaction's anchor output used as an
732 /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
733 fn sign_holder_anchor_input(
734 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
735 ) -> Result<Signature, ()>;
736 /// Signs a channel announcement message with our funding key proving it comes from one of the
737 /// channel participants.
739 /// Channel announcements also require a signature from each node's network key. Our node
740 /// signature is computed through [`NodeSigner::sign_gossip_message`].
742 /// Note that if this fails or is rejected, the channel will not be publicly announced and
743 /// our counterparty may (though likely will not) close the channel on us for violating the
745 fn sign_channel_announcement_with_funding_key(
746 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
747 ) -> Result<Signature, ()>;
750 /// A writeable signer.
752 /// There will always be two instances of a signer per channel, one occupied by the
753 /// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
755 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
756 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
757 pub trait WriteableEcdsaChannelSigner: EcdsaChannelSigner + Writeable {}
759 /// Specifies the recipient of an invoice.
761 /// This indicates to [`NodeSigner::sign_invoice`] what node secret key should be used to sign
764 /// The invoice should be signed with the local node secret key.
766 /// The invoice should be signed with the phantom node secret key. This secret key must be the
767 /// same for all nodes participating in the [phantom node payment].
769 /// [phantom node payment]: PhantomKeysManager
773 /// A trait that describes a source of entropy.
774 pub trait EntropySource {
775 /// Gets a unique, cryptographically-secure, random 32-byte value. This method must return a
776 /// different value each time it is called.
777 fn get_secure_random_bytes(&self) -> [u8; 32];
780 /// A trait that can handle cryptographic operations at the scope level of a node.
781 pub trait NodeSigner {
782 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
784 /// If the implementor of this trait supports [phantom node payments], then every node that is
785 /// intended to be included in the phantom invoice route hints must return the same value from
787 // This is because LDK avoids storing inbound payment data by encrypting payment data in the
788 // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
789 // nodes, they must share the key that encrypts this payment data.
791 /// This method must return the same value each time it is called.
793 /// [phantom node payments]: PhantomKeysManager
794 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
796 /// Get node id based on the provided [`Recipient`].
798 /// This method must return the same value each time it is called with a given [`Recipient`]
801 /// Errors if the [`Recipient`] variant is not supported by the implementation.
802 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
804 /// Gets the ECDH shared secret of our node secret and `other_key`, multiplying by `tweak` if
805 /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
806 /// secret, though this is less efficient.
808 /// Note that if this fails while attempting to forward an HTLC, LDK will panic. The error
809 /// should be resolved to allow LDK to resume forwarding HTLCs.
811 /// Errors if the [`Recipient`] variant is not supported by the implementation.
812 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
816 /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
817 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
818 /// blindly signing the hash.
820 /// The `hrp_bytes` are ASCII bytes, while the `invoice_data` is base32.
822 /// The secret key used to sign the invoice is dependent on the [`Recipient`].
824 /// Errors if the [`Recipient`] variant is not supported by the implementation.
825 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()>;
827 /// Signs the [`TaggedHash`] of a BOLT 12 invoice request.
829 /// May be called by a function passed to [`UnsignedInvoiceRequest::sign`] where
830 /// `invoice_request` is the callee.
832 /// Implementors may check that the `invoice_request` is expected rather than blindly signing
833 /// the tagged hash. An `Ok` result should sign `invoice_request.tagged_hash().as_digest()` with
834 /// the node's signing key or an ephemeral key to preserve privacy, whichever is associated with
835 /// [`UnsignedInvoiceRequest::payer_id`].
837 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
838 fn sign_bolt12_invoice_request(
839 &self, invoice_request: &UnsignedInvoiceRequest
840 ) -> Result<schnorr::Signature, ()>;
842 /// Signs the [`TaggedHash`] of a BOLT 12 invoice.
844 /// May be called by a function passed to [`UnsignedBolt12Invoice::sign`] where `invoice` is the
847 /// Implementors may check that the `invoice` is expected rather than blindly signing the tagged
848 /// hash. An `Ok` result should sign `invoice.tagged_hash().as_digest()` with the node's signing
849 /// key or an ephemeral key to preserve privacy, whichever is associated with
850 /// [`UnsignedBolt12Invoice::signing_pubkey`].
852 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
853 fn sign_bolt12_invoice(
854 &self, invoice: &UnsignedBolt12Invoice
855 ) -> Result<schnorr::Signature, ()>;
857 /// Sign a gossip message.
859 /// Note that if this fails, LDK may panic and the message will not be broadcast to the network
860 /// or a possible channel counterparty. If LDK panics, the error should be resolved to allow the
861 /// message to be broadcast, as otherwise it may prevent one from receiving funds over the
862 /// corresponding channel.
863 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
866 /// A trait that can return signer instances for individual channels.
867 pub trait SignerProvider {
868 /// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`].
869 type Signer : WriteableEcdsaChannelSigner;
871 /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::Signer`] through
872 /// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow
873 /// implementations of [`SignerProvider`] to maintain a mapping between itself and the generated
874 /// `channel_keys_id`.
876 /// This method must return a different value each time it is called.
877 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
879 /// Derives the private key material backing a `Signer`.
881 /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
882 /// [`SignerProvider::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
883 /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
884 /// [`ChannelSigner::channel_keys_id`].
885 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer;
887 /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream.
888 /// This is only called during deserialization of other objects which contain
889 /// [`WriteableEcdsaChannelSigner`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
890 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
891 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
892 /// you've read all of the provided bytes to ensure no corruption occurred.
894 /// This method is slowly being phased out -- it will only be called when reading objects
895 /// written by LDK versions prior to 0.0.113.
897 /// [`Signer`]: Self::Signer
898 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
899 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
900 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
902 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
904 /// If this function returns an error, this will result in a channel failing to open.
906 /// This method should return a different value each time it is called, to avoid linking
907 /// on-chain funds across channels as controlled to the same user.
908 fn get_destination_script(&self) -> Result<Script, ()>;
910 /// Get a script pubkey which we will send funds to when closing a channel.
912 /// If this function returns an error, this will result in a channel failing to open or close.
913 /// In the event of a failure when the counterparty is initiating a close, this can result in a
914 /// channel force close.
916 /// This method should return a different value each time it is called, to avoid linking
917 /// on-chain funds across channels as controlled to the same user.
918 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
921 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
923 /// This implementation performs no policy checks and is insufficient by itself as
924 /// a secure external signer.
926 pub struct InMemorySigner {
927 /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
928 /// holder's anchor output in a commitment transaction, if one is present.
929 pub funding_key: SecretKey,
930 /// Holder secret key for blinded revocation pubkey.
931 pub revocation_base_key: SecretKey,
932 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
933 pub payment_key: SecretKey,
934 /// Holder secret key used in an HTLC transaction.
935 pub delayed_payment_base_key: SecretKey,
936 /// Holder HTLC secret key used in commitment transaction HTLC outputs.
937 pub htlc_base_key: SecretKey,
939 pub commitment_seed: [u8; 32],
940 /// Holder public keys and basepoints.
941 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
942 /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
943 channel_parameters: Option<ChannelTransactionParameters>,
944 /// The total value of this channel.
945 channel_value_satoshis: u64,
946 /// Key derivation parameters.
947 channel_keys_id: [u8; 32],
948 /// Seed from which all randomness produced is derived from.
949 rand_bytes_unique_start: [u8; 32],
950 /// Tracks the number of times we've produced randomness to ensure we don't return the same
952 rand_bytes_index: AtomicCounter,
955 impl PartialEq for InMemorySigner {
956 fn eq(&self, other: &Self) -> bool {
957 self.funding_key == other.funding_key &&
958 self.revocation_base_key == other.revocation_base_key &&
959 self.payment_key == other.payment_key &&
960 self.delayed_payment_base_key == other.delayed_payment_base_key &&
961 self.htlc_base_key == other.htlc_base_key &&
962 self.commitment_seed == other.commitment_seed &&
963 self.holder_channel_pubkeys == other.holder_channel_pubkeys &&
964 self.channel_parameters == other.channel_parameters &&
965 self.channel_value_satoshis == other.channel_value_satoshis &&
966 self.channel_keys_id == other.channel_keys_id
970 impl Clone for InMemorySigner {
971 fn clone(&self) -> Self {
973 funding_key: self.funding_key.clone(),
974 revocation_base_key: self.revocation_base_key.clone(),
975 payment_key: self.payment_key.clone(),
976 delayed_payment_base_key: self.delayed_payment_base_key.clone(),
977 htlc_base_key: self.htlc_base_key.clone(),
978 commitment_seed: self.commitment_seed.clone(),
979 holder_channel_pubkeys: self.holder_channel_pubkeys.clone(),
980 channel_parameters: self.channel_parameters.clone(),
981 channel_value_satoshis: self.channel_value_satoshis,
982 channel_keys_id: self.channel_keys_id,
983 rand_bytes_unique_start: self.get_secure_random_bytes(),
984 rand_bytes_index: AtomicCounter::new(),
989 impl InMemorySigner {
990 /// Creates a new [`InMemorySigner`].
991 pub fn new<C: Signing>(
992 secp_ctx: &Secp256k1<C>,
993 funding_key: SecretKey,
994 revocation_base_key: SecretKey,
995 payment_key: SecretKey,
996 delayed_payment_base_key: SecretKey,
997 htlc_base_key: SecretKey,
998 commitment_seed: [u8; 32],
999 channel_value_satoshis: u64,
1000 channel_keys_id: [u8; 32],
1001 rand_bytes_unique_start: [u8; 32],
1002 ) -> InMemorySigner {
1003 let holder_channel_pubkeys =
1004 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
1005 &payment_key, &delayed_payment_base_key,
1009 revocation_base_key,
1011 delayed_payment_base_key,
1014 channel_value_satoshis,
1015 holder_channel_pubkeys,
1016 channel_parameters: None,
1018 rand_bytes_unique_start,
1019 rand_bytes_index: AtomicCounter::new(),
1023 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
1024 funding_key: &SecretKey,
1025 revocation_base_key: &SecretKey,
1026 payment_key: &SecretKey,
1027 delayed_payment_base_key: &SecretKey,
1028 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
1029 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
1031 funding_pubkey: from_secret(&funding_key),
1032 revocation_basepoint: from_secret(&revocation_base_key),
1033 payment_point: from_secret(&payment_key),
1034 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
1035 htlc_basepoint: from_secret(&htlc_base_key),
1039 /// Returns the counterparty's pubkeys.
1041 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1042 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1043 pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> {
1044 self.get_channel_parameters()
1045 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| ¶ms.pubkeys))
1048 /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
1049 /// transactions, i.e., the amount of time that we have to wait to recover our funds if we
1050 /// broadcast a transaction.
1052 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1053 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1054 pub fn counterparty_selected_contest_delay(&self) -> Option<u16> {
1055 self.get_channel_parameters()
1056 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay))
1059 /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
1060 /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
1061 /// if they broadcast a transaction.
1063 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1064 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1065 pub fn holder_selected_contest_delay(&self) -> Option<u16> {
1066 self.get_channel_parameters().map(|params| params.holder_selected_contest_delay)
1069 /// Returns whether the holder is the initiator.
1071 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1072 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1073 pub fn is_outbound(&self) -> Option<bool> {
1074 self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
1077 /// Funding outpoint
1079 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1080 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1081 pub fn funding_outpoint(&self) -> Option<&OutPoint> {
1082 self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
1085 /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
1086 /// building transactions.
1088 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1089 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1090 pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> {
1091 self.channel_parameters.as_ref()
1094 /// Returns the channel type features of the channel parameters. Should be helpful for
1095 /// determining a channel's category, i. e. legacy/anchors/taproot/etc.
1097 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1098 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1099 pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> {
1100 self.get_channel_parameters().map(|params| ¶ms.channel_type_features)
1103 /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
1104 /// by `descriptor`, returning the witness stack for the input.
1106 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1107 /// is not spending the outpoint described by [`descriptor.outpoint`],
1108 /// or if an output descriptor `script_pubkey` does not match the one we can spend.
1110 /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint
1111 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
1112 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1113 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1114 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1115 // bindings updates to support SigHashCache objects).
1116 if spend_tx.input.len() <= input_idx { return Err(()); }
1117 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1118 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1120 let remotepubkey = bitcoin::PublicKey::new(self.pubkeys().payment_point);
1121 // We cannot always assume that `channel_parameters` is set, so can't just call
1122 // `self.channel_parameters()` or anything that relies on it
1123 let supports_anchors_zero_fee_htlc_tx = self.channel_type_features()
1124 .map(|features| features.supports_anchors_zero_fee_htlc_tx())
1127 let witness_script = if supports_anchors_zero_fee_htlc_tx {
1128 chan_utils::get_to_countersignatory_with_anchors_redeemscript(&remotepubkey.inner)
1130 Script::new_p2pkh(&remotepubkey.pubkey_hash())
1132 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1133 let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self);
1134 let payment_script = if supports_anchors_zero_fee_htlc_tx {
1135 witness_script.to_v0_p2wsh()
1137 Script::new_v0_p2wpkh(&remotepubkey.wpubkey_hash().unwrap())
1140 if payment_script != descriptor.output.script_pubkey { return Err(()); }
1142 let mut witness = Vec::with_capacity(2);
1143 witness.push(remotesig.serialize_der().to_vec());
1144 witness[0].push(EcdsaSighashType::All as u8);
1145 if supports_anchors_zero_fee_htlc_tx {
1146 witness.push(witness_script.to_bytes());
1148 witness.push(remotepubkey.to_bytes());
1153 /// Sign the single input of `spend_tx` at index `input_idx` which spends the output
1154 /// described by `descriptor`, returning the witness stack for the input.
1156 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1157 /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
1158 /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
1159 /// `script_pubkey` does not match the one we can spend.
1161 /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
1162 /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
1163 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
1164 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1165 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1166 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1167 // bindings updates to support SigHashCache objects).
1168 if spend_tx.input.len() <= input_idx { return Err(()); }
1169 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1170 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1171 if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
1173 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
1174 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
1175 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
1176 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1177 let local_delayedsig = sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self);
1178 let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
1180 if descriptor.output.script_pubkey != payment_script { return Err(()); }
1182 let mut witness = Vec::with_capacity(3);
1183 witness.push(local_delayedsig.serialize_der().to_vec());
1184 witness[0].push(EcdsaSighashType::All as u8);
1185 witness.push(vec!()); //MINIMALIF
1186 witness.push(witness_script.clone().into_bytes());
1191 impl EntropySource for InMemorySigner {
1192 fn get_secure_random_bytes(&self) -> [u8; 32] {
1193 let index = self.rand_bytes_index.get_increment();
1194 let mut nonce = [0u8; 16];
1195 nonce[..8].copy_from_slice(&index.to_be_bytes());
1196 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1200 impl ChannelSigner for InMemorySigner {
1201 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
1202 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
1203 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
1206 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
1207 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
1210 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
1214 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
1216 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
1218 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
1219 assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
1220 if self.channel_parameters.is_some() {
1221 // The channel parameters were already set and they match, return early.
1224 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
1225 self.channel_parameters = Some(channel_parameters.clone());
1229 const MISSING_PARAMS_ERR: &'static str = "ChannelSigner::provide_channel_parameters must be called before signing operations";
1231 impl EcdsaChannelSigner for InMemorySigner {
1232 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
1233 let trusted_tx = commitment_tx.trust();
1234 let keys = trusted_tx.keys();
1236 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1237 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1238 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1240 let built_tx = trusted_tx.built_transaction();
1241 let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
1242 let commitment_txid = built_tx.txid;
1244 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
1245 for htlc in commitment_tx.htlcs() {
1246 let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
1247 let holder_selected_contest_delay =
1248 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1249 let chan_type = &channel_parameters.channel_type_features;
1250 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), holder_selected_contest_delay, htlc, chan_type, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1251 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, chan_type, &keys);
1252 let htlc_sighashtype = if chan_type.supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
1253 let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
1254 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
1255 htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
1258 Ok((commitment_sig, htlc_sigs))
1261 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
1265 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1266 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1267 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1268 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1269 let trusted_tx = commitment_tx.trust();
1270 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1273 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1274 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1275 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1276 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1277 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1278 let trusted_tx = commitment_tx.trust();
1279 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1282 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1283 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1284 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1285 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
1286 let witness_script = {
1287 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1288 let holder_selected_contest_delay =
1289 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1290 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.delayed_payment_basepoint);
1291 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, holder_selected_contest_delay, &counterparty_delayedpubkey)
1293 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1294 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1295 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1298 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1299 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1300 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1301 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
1302 let witness_script = {
1303 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1304 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.htlc_basepoint);
1305 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
1306 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1307 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
1309 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1310 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1311 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1314 fn sign_holder_htlc_transaction(
1315 &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
1316 secp_ctx: &Secp256k1<secp256k1::All>
1317 ) -> Result<Signature, ()> {
1318 let witness_script = htlc_descriptor.witness_script(secp_ctx);
1319 let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
1320 input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
1322 let our_htlc_private_key = chan_utils::derive_private_key(
1323 &secp_ctx, &htlc_descriptor.per_commitment_point, &self.htlc_base_key
1325 Ok(sign_with_aux_rand(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key, &self))
1328 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1329 let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
1330 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
1331 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1332 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.htlc_basepoint);
1333 let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
1334 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1335 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
1336 let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
1337 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1338 Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self))
1341 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1342 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1343 let counterparty_funding_key = &self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
1344 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, counterparty_funding_key);
1345 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
1348 fn sign_holder_anchor_input(
1349 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
1350 ) -> Result<Signature, ()> {
1351 let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
1352 let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
1353 input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
1355 Ok(sign_with_aux_rand(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key, &self))
1358 fn sign_channel_announcement_with_funding_key(
1359 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
1360 ) -> Result<Signature, ()> {
1361 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1362 Ok(secp_ctx.sign_ecdsa(&msghash, &self.funding_key))
1366 const SERIALIZATION_VERSION: u8 = 1;
1368 const MIN_SERIALIZATION_VERSION: u8 = 1;
1370 impl WriteableEcdsaChannelSigner for InMemorySigner {}
1372 impl Writeable for InMemorySigner {
1373 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
1374 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
1376 self.funding_key.write(writer)?;
1377 self.revocation_base_key.write(writer)?;
1378 self.payment_key.write(writer)?;
1379 self.delayed_payment_base_key.write(writer)?;
1380 self.htlc_base_key.write(writer)?;
1381 self.commitment_seed.write(writer)?;
1382 self.channel_parameters.write(writer)?;
1383 self.channel_value_satoshis.write(writer)?;
1384 self.channel_keys_id.write(writer)?;
1386 write_tlv_fields!(writer, {});
1392 impl<ES: Deref> ReadableArgs<ES> for InMemorySigner where ES::Target: EntropySource {
1393 fn read<R: io::Read>(reader: &mut R, entropy_source: ES) -> Result<Self, DecodeError> {
1394 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
1396 let funding_key = Readable::read(reader)?;
1397 let revocation_base_key = Readable::read(reader)?;
1398 let payment_key = Readable::read(reader)?;
1399 let delayed_payment_base_key = Readable::read(reader)?;
1400 let htlc_base_key = Readable::read(reader)?;
1401 let commitment_seed = Readable::read(reader)?;
1402 let counterparty_channel_data = Readable::read(reader)?;
1403 let channel_value_satoshis = Readable::read(reader)?;
1404 let secp_ctx = Secp256k1::signing_only();
1405 let holder_channel_pubkeys =
1406 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
1407 &payment_key, &delayed_payment_base_key, &htlc_base_key);
1408 let keys_id = Readable::read(reader)?;
1410 read_tlv_fields!(reader, {});
1414 revocation_base_key,
1416 delayed_payment_base_key,
1419 channel_value_satoshis,
1420 holder_channel_pubkeys,
1421 channel_parameters: counterparty_channel_data,
1422 channel_keys_id: keys_id,
1423 rand_bytes_unique_start: entropy_source.get_secure_random_bytes(),
1424 rand_bytes_index: AtomicCounter::new(),
1429 /// Simple implementation of [`EntropySource`], [`NodeSigner`], and [`SignerProvider`] that takes a
1430 /// 32-byte seed for use as a BIP 32 extended key and derives keys from that.
1432 /// Your `node_id` is seed/0'.
1433 /// Unilateral closes may use seed/1'.
1434 /// Cooperative closes may use seed/2'.
1435 /// The two close keys may be needed to claim on-chain funds!
1437 /// This struct cannot be used for nodes that wish to support receiving phantom payments;
1438 /// [`PhantomKeysManager`] must be used instead.
1440 /// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
1441 /// previously issued invoices and attempts to pay previous invoices will fail.
1442 pub struct KeysManager {
1443 secp_ctx: Secp256k1<secp256k1::All>,
1444 node_secret: SecretKey,
1446 inbound_payment_key: KeyMaterial,
1447 destination_script: Script,
1448 shutdown_pubkey: PublicKey,
1449 channel_master_key: ExtendedPrivKey,
1450 channel_child_index: AtomicUsize,
1452 rand_bytes_unique_start: [u8; 32],
1453 rand_bytes_index: AtomicCounter,
1456 starting_time_secs: u64,
1457 starting_time_nanos: u32,
1461 /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
1462 /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
1463 /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
1464 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
1465 /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
1466 /// is to simply use the current time (with very high precision).
1468 /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
1469 /// obviously, `starting_time` should be unique every time you reload the library - it is only
1470 /// used to generate new ephemeral key data (which will be stored by the individual channel if
1473 /// Note that the seed is required to recover certain on-chain funds independent of
1474 /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
1475 /// for any channel, and some on-chain during-closing funds.
1477 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
1478 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
1479 let secp_ctx = Secp256k1::new();
1480 // Note that when we aren't serializing the key, network doesn't matter
1481 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
1483 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key;
1484 let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret);
1485 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
1486 Ok(destination_key) => {
1487 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
1488 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1489 .push_slice(&wpubkey_hash.into_inner())
1492 Err(_) => panic!("Your RNG is busted"),
1494 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
1495 Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key,
1496 Err(_) => panic!("Your RNG is busted"),
1498 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
1499 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key;
1500 let mut inbound_pmt_key_bytes = [0; 32];
1501 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
1503 let mut rand_bytes_engine = Sha256::engine();
1504 rand_bytes_engine.input(&starting_time_secs.to_be_bytes());
1505 rand_bytes_engine.input(&starting_time_nanos.to_be_bytes());
1506 rand_bytes_engine.input(seed);
1507 rand_bytes_engine.input(b"LDK PRNG Seed");
1508 let rand_bytes_unique_start = Sha256::from_engine(rand_bytes_engine).into_inner();
1510 let mut res = KeysManager {
1514 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
1520 channel_child_index: AtomicUsize::new(0),
1522 rand_bytes_unique_start,
1523 rand_bytes_index: AtomicCounter::new(),
1527 starting_time_nanos,
1529 let secp_seed = res.get_secure_random_bytes();
1530 res.secp_ctx.seeded_randomize(&secp_seed);
1533 Err(_) => panic!("Your rng is busted"),
1537 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1538 pub fn get_node_secret_key(&self) -> SecretKey {
1542 /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters.
1543 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1544 let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
1545 let mut unique_start = Sha256::engine();
1546 unique_start.input(params);
1547 unique_start.input(&self.seed);
1549 // We only seriously intend to rely on the channel_master_key for true secure
1550 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
1551 // starting_time provided in the constructor) to be unique.
1552 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx,
1553 ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted")
1554 ).expect("Your RNG is busted");
1555 unique_start.input(&child_privkey.private_key[..]);
1557 let seed = Sha256::from_engine(unique_start).into_inner();
1559 let commitment_seed = {
1560 let mut sha = Sha256::engine();
1562 sha.input(&b"commitment seed"[..]);
1563 Sha256::from_engine(sha).into_inner()
1565 macro_rules! key_step {
1566 ($info: expr, $prev_key: expr) => {{
1567 let mut sha = Sha256::engine();
1569 sha.input(&$prev_key[..]);
1570 sha.input(&$info[..]);
1571 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
1574 let funding_key = key_step!(b"funding key", commitment_seed);
1575 let revocation_base_key = key_step!(b"revocation base key", funding_key);
1576 let payment_key = key_step!(b"payment key", revocation_base_key);
1577 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
1578 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
1579 let prng_seed = self.get_secure_random_bytes();
1581 InMemorySigner::new(
1584 revocation_base_key,
1586 delayed_payment_base_key,
1589 channel_value_satoshis,
1595 /// Signs the given [`PartiallySignedTransaction`] which spends the given [`SpendableOutputDescriptor`]s.
1596 /// The resulting inputs will be finalized and the PSBT will be ready for broadcast if there
1597 /// are no other inputs that need signing.
1599 /// Returns `Err(())` if the PSBT is missing a descriptor or if we fail to sign.
1601 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1602 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1603 pub fn sign_spendable_outputs_psbt<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], mut psbt: PartiallySignedTransaction, secp_ctx: &Secp256k1<C>) -> Result<PartiallySignedTransaction, ()> {
1604 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
1605 for outp in descriptors {
1607 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1608 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1609 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1610 let mut signer = self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id);
1611 if let Some(channel_params) = descriptor.channel_transaction_parameters.as_ref() {
1612 signer.provide_channel_parameters(channel_params);
1614 keys_cache = Some((signer, descriptor.channel_keys_id));
1616 let witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?);
1617 psbt.inputs[input_idx].final_script_witness = Some(witness);
1619 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1620 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1621 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1623 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1624 descriptor.channel_keys_id));
1626 let witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?);
1627 psbt.inputs[input_idx].final_script_witness = Some(witness);
1629 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
1630 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == outpoint.into_bitcoin_outpoint()).ok_or(())?;
1631 let derivation_idx = if output.script_pubkey == self.destination_script {
1637 // Note that when we aren't serializing the key, network doesn't matter
1638 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1640 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1642 Err(_) => panic!("Your RNG is busted"),
1645 Err(_) => panic!("Your rng is busted"),
1648 let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
1649 if derivation_idx == 2 {
1650 assert_eq!(pubkey.inner, self.shutdown_pubkey);
1652 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1653 let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey();
1655 if payment_script != output.script_pubkey { return Err(()); };
1657 let sighash = hash_to_message!(&sighash::SighashCache::new(&psbt.unsigned_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
1658 let sig = sign_with_aux_rand(secp_ctx, &sighash, &secret.private_key, &self);
1659 let mut sig_ser = sig.serialize_der().to_vec();
1660 sig_ser.push(EcdsaSighashType::All as u8);
1661 let witness = Witness::from_vec(vec![sig_ser, pubkey.inner.serialize().to_vec()]);
1662 psbt.inputs[input_idx].final_script_witness = Some(witness);
1670 /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
1671 /// output to the given change destination (if sufficient change value remains). The
1672 /// transaction will have a feerate, at least, of the given value.
1674 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
1675 /// transaction will have a locktime of 0. It it recommended to set this to the current block
1676 /// height to avoid fee sniping, unless you have some specific reason to use a different
1679 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
1680 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
1681 /// does not match the one we can spend.
1683 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
1685 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1686 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1687 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option<PackedLockTime>, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1688 let (mut psbt, expected_max_weight) = SpendableOutputDescriptor::create_spendable_outputs_psbt(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime)?;
1689 psbt = self.sign_spendable_outputs_psbt(descriptors, psbt, secp_ctx)?;
1691 let spend_tx = psbt.extract_tx();
1693 debug_assert!(expected_max_weight >= spend_tx.weight());
1694 // Note that witnesses with a signature vary somewhat in size, so allow
1695 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1696 debug_assert!(expected_max_weight <= spend_tx.weight() + descriptors.len() * 3);
1702 impl EntropySource for KeysManager {
1703 fn get_secure_random_bytes(&self) -> [u8; 32] {
1704 let index = self.rand_bytes_index.get_increment();
1705 let mut nonce = [0u8; 16];
1706 nonce[..8].copy_from_slice(&index.to_be_bytes());
1707 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1711 impl NodeSigner for KeysManager {
1712 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1714 Recipient::Node => Ok(self.node_id.clone()),
1715 Recipient::PhantomNode => Err(())
1719 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1720 let mut node_secret = match recipient {
1721 Recipient::Node => Ok(self.node_secret.clone()),
1722 Recipient::PhantomNode => Err(())
1724 if let Some(tweak) = tweak {
1725 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1727 Ok(SharedSecret::new(other_key, &node_secret))
1730 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1731 self.inbound_payment_key.clone()
1734 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1735 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1736 let secret = match recipient {
1737 Recipient::Node => Ok(&self.node_secret),
1738 Recipient::PhantomNode => Err(())
1740 Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret))
1743 fn sign_bolt12_invoice_request(
1744 &self, invoice_request: &UnsignedInvoiceRequest
1745 ) -> Result<schnorr::Signature, ()> {
1746 let message = invoice_request.tagged_hash().as_digest();
1747 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1748 let aux_rand = self.get_secure_random_bytes();
1749 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1752 fn sign_bolt12_invoice(
1753 &self, invoice: &UnsignedBolt12Invoice
1754 ) -> Result<schnorr::Signature, ()> {
1755 let message = invoice.tagged_hash().as_digest();
1756 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1757 let aux_rand = self.get_secure_random_bytes();
1758 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1761 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1762 let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1763 Ok(self.secp_ctx.sign_ecdsa(&msg_hash, &self.node_secret))
1767 impl SignerProvider for KeysManager {
1768 type Signer = InMemorySigner;
1770 fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1771 let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1772 // `child_idx` is the only thing guaranteed to make each channel unique without a restart
1773 // (though `user_channel_id` should help, depending on user behavior). If it manages to
1774 // roll over, we may generate duplicate keys for two different channels, which could result
1775 // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
1776 // doesn't reach `u32::MAX`.
1777 assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
1778 let mut id = [0; 32];
1779 id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
1780 id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
1781 id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
1782 id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
1786 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1787 self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
1790 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1791 InMemorySigner::read(&mut io::Cursor::new(reader), self)
1794 fn get_destination_script(&self) -> Result<Script, ()> {
1795 Ok(self.destination_script.clone())
1798 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1799 Ok(ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone()))
1803 /// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
1806 /// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
1807 /// paid to one of multiple nodes. This works because we encode the invoice route hints such that
1808 /// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
1809 /// itself without ever needing to forward to this fake node.
1811 /// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
1812 /// provide some fault tolerance, because payers will automatically retry paying other provided
1813 /// nodes in the case that one node goes down.
1815 /// Note that multi-path payments are not supported in phantom invoices for security reasons.
1816 // In the hypothetical case that we did support MPP phantom payments, there would be no way for
1817 // nodes to know when the full payment has been received (and the preimage can be released) without
1818 // significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
1819 // to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
1820 // is released too early.
1822 /// Switching between this struct and [`KeysManager`] will invalidate any previously issued
1823 /// invoices and attempts to pay previous invoices will fail.
1824 pub struct PhantomKeysManager {
1826 inbound_payment_key: KeyMaterial,
1827 phantom_secret: SecretKey,
1828 phantom_node_id: PublicKey,
1831 impl EntropySource for PhantomKeysManager {
1832 fn get_secure_random_bytes(&self) -> [u8; 32] {
1833 self.inner.get_secure_random_bytes()
1837 impl NodeSigner for PhantomKeysManager {
1838 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1840 Recipient::Node => self.inner.get_node_id(Recipient::Node),
1841 Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
1845 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1846 let mut node_secret = match recipient {
1847 Recipient::Node => self.inner.node_secret.clone(),
1848 Recipient::PhantomNode => self.phantom_secret.clone(),
1850 if let Some(tweak) = tweak {
1851 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1853 Ok(SharedSecret::new(other_key, &node_secret))
1856 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1857 self.inbound_payment_key.clone()
1860 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1861 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1862 let secret = match recipient {
1863 Recipient::Node => &self.inner.node_secret,
1864 Recipient::PhantomNode => &self.phantom_secret,
1866 Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret))
1869 fn sign_bolt12_invoice_request(
1870 &self, invoice_request: &UnsignedInvoiceRequest
1871 ) -> Result<schnorr::Signature, ()> {
1872 self.inner.sign_bolt12_invoice_request(invoice_request)
1875 fn sign_bolt12_invoice(
1876 &self, invoice: &UnsignedBolt12Invoice
1877 ) -> Result<schnorr::Signature, ()> {
1878 self.inner.sign_bolt12_invoice(invoice)
1881 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1882 self.inner.sign_gossip_message(msg)
1886 impl SignerProvider for PhantomKeysManager {
1887 type Signer = InMemorySigner;
1889 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1890 self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
1893 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1894 self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
1897 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1898 self.inner.read_chan_signer(reader)
1901 fn get_destination_script(&self) -> Result<Script, ()> {
1902 self.inner.get_destination_script()
1905 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1906 self.inner.get_shutdown_scriptpubkey()
1910 impl PhantomKeysManager {
1911 /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
1912 /// that is shared across all nodes that intend to participate in [phantom node payments]
1915 /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
1916 /// `starting_time_nanos`.
1918 /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
1919 /// same across restarts, or else inbound payments may fail.
1921 /// [phantom node payments]: PhantomKeysManager
1922 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self {
1923 let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos);
1924 let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed);
1925 let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
1926 let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
1929 inbound_payment_key: KeyMaterial(inbound_key),
1935 /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
1936 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option<PackedLockTime>, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1937 self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime, secp_ctx)
1940 /// See [`KeysManager::derive_channel_keys`] for documentation on this method.
1941 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1942 self.inner.derive_channel_keys(channel_value_satoshis, params)
1945 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1946 pub fn get_node_secret_key(&self) -> SecretKey {
1947 self.inner.get_node_secret_key()
1950 /// Gets the "node_id" secret key of the phantom node used to sign invoices, decode the
1951 /// last-hop onion data, etc.
1952 pub fn get_phantom_node_secret_key(&self) -> SecretKey {
1957 // Ensure that EcdsaChannelSigner can have a vtable
1960 let _signer: Box<dyn EcdsaChannelSigner>;
1965 use std::sync::{Arc, mpsc};
1966 use std::sync::mpsc::TryRecvError;
1968 use std::time::Duration;
1969 use bitcoin::blockdata::constants::genesis_block;
1970 use bitcoin::Network;
1971 use crate::sign::{EntropySource, KeysManager};
1973 use criterion::Criterion;
1975 pub fn bench_get_secure_random_bytes(bench: &mut Criterion) {
1976 let seed = [0u8; 32];
1977 let now = Duration::from_secs(genesis_block(Network::Testnet).header.time as u64);
1978 let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_micros()));
1980 let mut handles = Vec::new();
1981 let mut stops = Vec::new();
1983 let keys_manager_clone = Arc::clone(&keys_manager);
1984 let (stop_sender, stop_receiver) = mpsc::channel();
1985 let handle = thread::spawn(move || {
1987 keys_manager_clone.get_secure_random_bytes();
1988 match stop_receiver.try_recv() {
1989 Ok(_) | Err(TryRecvError::Disconnected) => {
1990 println!("Terminating.");
1993 Err(TryRecvError::Empty) => {}
1997 handles.push(handle);
1998 stops.push(stop_sender);
2001 bench.bench_function("get_secure_random_bytes", |b| b.iter(||
2002 keys_manager.get_secure_random_bytes()));
2005 let _ = stop.send(());
2007 for handle in handles {
2008 handle.join().unwrap();