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::locktime::absolute::LockTime;
16 use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn};
17 use bitcoin::blockdata::script::{Script, ScriptBuf, Builder};
18 use bitcoin::blockdata::opcodes;
19 use bitcoin::ecdsa::Signature as EcdsaSignature;
20 use bitcoin::network::constants::Network;
21 use bitcoin::psbt::PartiallySignedTransaction;
22 use bitcoin::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
24 use bitcoin::sighash::EcdsaSighashType;
26 use bitcoin::bech32::u5;
27 use bitcoin::hashes::{Hash, HashEngine};
28 use bitcoin::hashes::sha256::Hash as Sha256;
29 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
30 use bitcoin::hash_types::WPubkeyHash;
32 use bitcoin::secp256k1::{KeyPair, PublicKey, Scalar, Secp256k1, SecretKey, Signing};
33 use bitcoin::secp256k1::ecdh::SharedSecret;
34 use bitcoin::secp256k1::ecdsa::{RecoverableSignature, Signature};
35 use bitcoin::secp256k1::schnorr;
36 use bitcoin::{secp256k1, Sequence, Witness, Txid};
38 use crate::util::transaction_utils;
39 use crate::util::crypto::{hkdf_extract_expand_twice, sign, sign_with_aux_rand};
40 use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
41 use crate::chain::transaction::OutPoint;
42 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
43 use crate::ln::{chan_utils, PaymentPreimage};
44 use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
45 use crate::ln::channel_keys::{DelayedPaymentBasepoint, DelayedPaymentKey, HtlcKey, HtlcBasepoint, RevocationKey, RevocationBasepoint};
46 use crate::ln::msgs::{UnsignedChannelAnnouncement, UnsignedGossipMessage};
47 use crate::ln::script::ShutdownScript;
48 use crate::offers::invoice::UnsignedBolt12Invoice;
49 use crate::offers::invoice_request::UnsignedInvoiceRequest;
51 use crate::prelude::*;
52 use core::convert::TryInto;
54 use core::sync::atomic::{AtomicUsize, Ordering};
55 use crate::io::{self, Error};
56 use crate::ln::features::ChannelTypeFeatures;
57 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
58 use crate::util::atomic_counter::AtomicCounter;
59 use crate::util::chacha20::ChaCha20;
60 use crate::util::invoice::construct_invoice_preimage;
62 pub(crate) mod type_resolver;
64 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
65 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
67 /// This is not exported to bindings users as we just use `[u8; 32]` directly
68 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
69 pub struct KeyMaterial(pub [u8; 32]);
71 /// Information about a spendable output to a P2WSH script.
73 /// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
74 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
75 pub struct DelayedPaymentOutputDescriptor {
76 /// The outpoint which is spendable.
77 pub outpoint: OutPoint,
78 /// Per commitment point to derive the delayed payment key by key holder.
79 pub per_commitment_point: PublicKey,
80 /// The `nSequence` value which must be set in the spending input to satisfy the `OP_CSV` in
81 /// the witness_script.
82 pub to_self_delay: u16,
83 /// The output which is referenced by the given outpoint.
85 /// The revocation point specific to the commitment transaction which was broadcast. Used to
86 /// derive the witnessScript for this output.
87 pub revocation_pubkey: RevocationKey,
88 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
89 /// This may be useful in re-deriving keys used in the channel to spend the output.
90 pub channel_keys_id: [u8; 32],
91 /// The value of the channel which this output originated from, possibly indirectly.
92 pub channel_value_satoshis: u64,
94 impl DelayedPaymentOutputDescriptor {
95 /// The maximum length a well-formed witness spending one of these should have.
96 /// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
98 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
99 // redeemscript push length.
100 pub const MAX_WITNESS_LENGTH: u64 = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH as u64 + 1;
103 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
104 (0, outpoint, required),
105 (2, per_commitment_point, required),
106 (4, to_self_delay, required),
107 (6, output, required),
108 (8, revocation_pubkey, required),
109 (10, channel_keys_id, required),
110 (12, channel_value_satoshis, required),
113 pub(crate) const P2WPKH_WITNESS_WEIGHT: u64 = 1 /* num stack items */ +
115 73 /* sig including sighash flag */ +
116 1 /* pubkey length */ +
119 /// Information about a spendable output to our "payment key".
121 /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
122 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
123 pub struct StaticPaymentOutputDescriptor {
124 /// The outpoint which is spendable.
125 pub outpoint: OutPoint,
126 /// The output which is referenced by the given outpoint.
128 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
129 /// This may be useful in re-deriving keys used in the channel to spend the output.
130 pub channel_keys_id: [u8; 32],
131 /// The value of the channel which this transactions spends.
132 pub channel_value_satoshis: u64,
133 /// The necessary channel parameters that need to be provided to the re-derived signer through
134 /// [`ChannelSigner::provide_channel_parameters`].
136 /// Added as optional, but always `Some` if the descriptor was produced in v0.0.117 or later.
137 pub channel_transaction_parameters: Option<ChannelTransactionParameters>,
139 impl StaticPaymentOutputDescriptor {
140 /// Returns the `witness_script` of the spendable output.
142 /// Note that this will only return `Some` for [`StaticPaymentOutputDescriptor`]s that
143 /// originated from an anchor outputs channel, as they take the form of a P2WSH script.
144 pub fn witness_script(&self) -> Option<ScriptBuf> {
145 self.channel_transaction_parameters.as_ref()
146 .and_then(|channel_params|
147 if channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
148 let payment_point = channel_params.holder_pubkeys.payment_point;
149 Some(chan_utils::get_to_countersignatory_with_anchors_redeemscript(&payment_point))
156 /// The maximum length a well-formed witness spending one of these should have.
157 /// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
159 pub fn max_witness_length(&self) -> u64 {
160 if self.channel_transaction_parameters.as_ref()
161 .map(|channel_params| channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx())
164 let witness_script_weight = 1 /* pubkey push */ + 33 /* pubkey */ +
165 1 /* OP_CHECKSIGVERIFY */ + 1 /* OP_1 */ + 1 /* OP_CHECKSEQUENCEVERIFY */;
166 1 /* num witness items */ + 1 /* sig push */ + 73 /* sig including sighash flag */ +
167 1 /* witness script push */ + witness_script_weight
169 P2WPKH_WITNESS_WEIGHT
173 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
174 (0, outpoint, required),
175 (2, output, required),
176 (4, channel_keys_id, required),
177 (6, channel_value_satoshis, required),
178 (7, channel_transaction_parameters, option),
181 /// Describes the necessary information to spend a spendable output.
183 /// When on-chain outputs are created by LDK (which our counterparty is not able to claim at any
184 /// point in the future) a [`SpendableOutputs`] event is generated which you must track and be able
185 /// to spend on-chain. The information needed to do this is provided in this enum, including the
186 /// outpoint describing which `txid` and output `index` is available, the full output which exists
187 /// at that `txid`/`index`, and any keys or other information required to sign.
189 /// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
190 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
191 pub enum SpendableOutputDescriptor {
192 /// An output to a script which was provided via [`SignerProvider`] directly, either from
193 /// [`get_destination_script`] or [`get_shutdown_scriptpubkey`], thus you should already
194 /// know how to spend it. No secret keys are provided as LDK was never given any key.
195 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
196 /// on-chain using the payment preimage or after it has timed out.
198 /// [`get_shutdown_scriptpubkey`]: SignerProvider::get_shutdown_scriptpubkey
199 /// [`get_destination_script`]: SignerProvider::get_shutdown_scriptpubkey
201 /// The outpoint which is spendable.
203 /// The output which is referenced by the given outpoint.
205 /// The `channel_keys_id` for the channel which this output came from.
207 /// For channels which were generated on LDK 0.0.119 or later, this is the value which was
208 /// passed to the [`SignerProvider::get_destination_script`] call which provided this
211 /// For channels which were generated prior to LDK 0.0.119, no such argument existed,
212 /// however this field may still be filled in if such data is available.
213 channel_keys_id: Option<[u8; 32]>
215 /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
218 /// The witness in the spending input should be:
220 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
223 /// Note that the `nSequence` field in the spending input must be set to
224 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
225 /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
226 /// the outpoint confirms, see [BIP
227 /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
228 /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
231 /// These are generally the result of a "revocable" output to us, spendable only by us unless
232 /// it is an output from an old state which we broadcast (which should never happen).
234 /// To derive the delayed payment key which is used to sign this input, you must pass the
235 /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the
236 /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`ChannelSigner::pubkeys`]) and the provided
237 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The DelayedPaymentKey can be
238 /// generated without the secret key using [`DelayedPaymentKey::from_basepoint`] and only the
239 /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`].
241 /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
242 /// used in the witness script generation), you must pass the counterparty
243 /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to
244 /// [`ChannelSigner::provide_channel_parameters`]) and the provided
245 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to
246 /// [`RevocationKey`].
248 /// The witness script which is hashed and included in the output `script_pubkey` may be
249 /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
250 /// as explained above), our delayed payment pubkey (derived as explained above), and the
251 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to
252 /// [`chan_utils::get_revokeable_redeemscript`].
253 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
254 /// An output spendable exclusively by our payment key (i.e., the private key that corresponds
255 /// to the `payment_point` in [`ChannelSigner::pubkeys`]). The output type depends on the
256 /// channel type negotiated.
258 /// On an anchor outputs channel, the witness in the spending input is:
260 /// <BIP 143 signature> <witness script>
263 /// Otherwise, it is:
265 /// <BIP 143 signature> <payment key>
268 /// These are generally the result of our counterparty having broadcast the current state,
269 /// allowing us to claim the non-HTLC-encumbered outputs immediately, or after one confirmation
270 /// in the case of anchor outputs channels.
271 StaticPaymentOutput(StaticPaymentOutputDescriptor),
274 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
275 (0, StaticOutput) => {
276 (0, outpoint, required),
277 (1, channel_keys_id, option),
278 (2, output, required),
281 (1, DelayedPaymentOutput),
282 (2, StaticPaymentOutput),
285 impl SpendableOutputDescriptor {
286 /// Turns this into a [`bitcoin::psbt::Input`] which can be used to create a
287 /// [`PartiallySignedTransaction`] which spends the given descriptor.
289 /// Note that this does not include any signatures, just the information required to
290 /// construct the transaction and sign it.
292 /// This is not exported to bindings users as there is no standard serialization for an input.
293 /// See [`Self::create_spendable_outputs_psbt`] instead.
294 pub fn to_psbt_input(&self) -> bitcoin::psbt::Input {
296 SpendableOutputDescriptor::StaticOutput { output, .. } => {
297 // Is a standard P2WPKH, no need for witness script
298 bitcoin::psbt::Input {
299 witness_utxo: Some(output.clone()),
303 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
304 // TODO we could add the witness script as well
305 bitcoin::psbt::Input {
306 witness_utxo: Some(descriptor.output.clone()),
310 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
311 // TODO we could add the witness script as well
312 bitcoin::psbt::Input {
313 witness_utxo: Some(descriptor.output.clone()),
320 /// Creates an unsigned [`PartiallySignedTransaction`] which spends the given descriptors to
321 /// the given outputs, plus an output to the given change destination (if sufficient
322 /// change value remains). The PSBT will have a feerate, at least, of the given value.
324 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
325 /// transaction will have a locktime of 0. It it recommended to set this to the current block
326 /// height to avoid fee sniping, unless you have some specific reason to use a different
329 /// Returns the PSBT and expected max transaction weight.
331 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
332 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
333 /// does not match the one we can spend.
335 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
336 pub fn create_spendable_outputs_psbt(descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, locktime: Option<LockTime>) -> Result<(PartiallySignedTransaction, u64), ()> {
337 let mut input = Vec::with_capacity(descriptors.len());
338 let mut input_value = 0;
339 let mut witness_weight = 0;
340 let mut output_set = HashSet::with_capacity(descriptors.len());
341 for outp in descriptors {
343 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
344 if !output_set.insert(descriptor.outpoint) { return Err(()); }
346 if descriptor.channel_transaction_parameters.as_ref()
347 .map(|channel_params| channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx())
350 Sequence::from_consensus(1)
355 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
356 script_sig: ScriptBuf::new(),
358 witness: Witness::new(),
360 witness_weight += descriptor.max_witness_length();
361 #[cfg(feature = "grind_signatures")]
362 { witness_weight -= 1; } // Guarantees a low R signature
363 input_value += descriptor.output.value;
365 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
366 if !output_set.insert(descriptor.outpoint) { return Err(()); }
368 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
369 script_sig: ScriptBuf::new(),
370 sequence: Sequence(descriptor.to_self_delay as u32),
371 witness: Witness::new(),
373 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
374 #[cfg(feature = "grind_signatures")]
375 { witness_weight -= 1; } // Guarantees a low R signature
376 input_value += descriptor.output.value;
378 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output, .. } => {
379 if !output_set.insert(*outpoint) { return Err(()); }
381 previous_output: outpoint.into_bitcoin_outpoint(),
382 script_sig: ScriptBuf::new(),
383 sequence: Sequence::ZERO,
384 witness: Witness::new(),
386 witness_weight += 1 + 73 + 34;
387 #[cfg(feature = "grind_signatures")]
388 { witness_weight -= 1; } // Guarantees a low R signature
389 input_value += output.value;
392 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
394 let mut tx = Transaction {
396 lock_time: locktime.unwrap_or(LockTime::ZERO),
400 let expected_max_weight =
401 transaction_utils::maybe_add_change_output(&mut tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
403 let psbt_inputs = descriptors.iter().map(|d| d.to_psbt_input()).collect::<Vec<_>>();
404 let psbt = PartiallySignedTransaction {
406 outputs: vec![Default::default(); tx.output.len()],
408 xpub: Default::default(),
410 proprietary: Default::default(),
411 unknown: Default::default(),
413 Ok((psbt, expected_max_weight))
417 /// The parameters required to derive a channel signer via [`SignerProvider`].
418 #[derive(Clone, Debug, PartialEq, Eq)]
419 pub struct ChannelDerivationParameters {
420 /// The value in satoshis of the channel we're attempting to spend the anchor output of.
421 pub value_satoshis: u64,
422 /// The unique identifier to re-derive the signer for the associated channel.
423 pub keys_id: [u8; 32],
424 /// The necessary channel parameters that need to be provided to the re-derived signer through
425 /// [`ChannelSigner::provide_channel_parameters`].
426 pub transaction_parameters: ChannelTransactionParameters,
429 impl_writeable_tlv_based!(ChannelDerivationParameters, {
430 (0, value_satoshis, required),
431 (2, keys_id, required),
432 (4, transaction_parameters, required),
435 /// A descriptor used to sign for a commitment transaction's HTLC output.
436 #[derive(Clone, Debug, PartialEq, Eq)]
437 pub struct HTLCDescriptor {
438 /// The parameters required to derive the signer for the HTLC input.
439 pub channel_derivation_parameters: ChannelDerivationParameters,
440 /// The txid of the commitment transaction in which the HTLC output lives.
441 pub commitment_txid: Txid,
442 /// The number of the commitment transaction in which the HTLC output lives.
443 pub per_commitment_number: u64,
444 /// The key tweak corresponding to the number of the commitment transaction in which the HTLC
445 /// output lives. This tweak is applied to all the basepoints for both parties in the channel to
446 /// arrive at unique keys per commitment.
448 /// See <https://github.com/lightning/bolts/blob/master/03-transactions.md#keys> for more info.
449 pub per_commitment_point: PublicKey,
450 /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs
451 /// originating from a channel supporting anchor outputs, otherwise it is the channel's
452 /// negotiated feerate at the time the commitment transaction was built.
453 pub feerate_per_kw: u32,
454 /// The details of the HTLC as it appears in the commitment transaction.
455 pub htlc: HTLCOutputInCommitment,
456 /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be
458 pub preimage: Option<PaymentPreimage>,
459 /// The counterparty's signature required to spend the HTLC output.
460 pub counterparty_sig: Signature
463 impl_writeable_tlv_based!(HTLCDescriptor, {
464 (0, channel_derivation_parameters, required),
465 (1, feerate_per_kw, (default_value, 0)),
466 (2, commitment_txid, required),
467 (4, per_commitment_number, required),
468 (6, per_commitment_point, required),
470 (10, preimage, option),
471 (12, counterparty_sig, required),
474 impl HTLCDescriptor {
475 /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint
476 /// being spent by the HTLC input in the HTLC transaction.
477 pub fn outpoint(&self) -> bitcoin::OutPoint {
479 txid: self.commitment_txid,
480 vout: self.htlc.transaction_output_index.unwrap(),
484 /// Returns the UTXO to be spent by the HTLC input, which can be obtained via
485 /// [`Self::unsigned_tx_input`].
486 pub fn previous_utxo<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
488 script_pubkey: self.witness_script(secp).to_v0_p2wsh(),
489 value: self.htlc.amount_msat / 1000,
493 /// Returns the unsigned transaction input spending the HTLC output in the commitment
495 pub fn unsigned_tx_input(&self) -> TxIn {
496 chan_utils::build_htlc_input(
497 &self.commitment_txid, &self.htlc, &self.channel_derivation_parameters.transaction_parameters.channel_type_features
501 /// Returns the delayed output created as a result of spending the HTLC output in the commitment
503 pub fn tx_output<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
504 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
505 let broadcaster_keys = channel_params.broadcaster_pubkeys();
506 let counterparty_keys = channel_params.countersignatory_pubkeys();
507 let broadcaster_delayed_key = DelayedPaymentKey::from_basepoint(
508 secp, &broadcaster_keys.delayed_payment_basepoint, &self.per_commitment_point
510 let counterparty_revocation_key = &RevocationKey::from_basepoint(&secp, &counterparty_keys.revocation_basepoint, &self.per_commitment_point);
511 chan_utils::build_htlc_output(
512 self.feerate_per_kw, channel_params.contest_delay(), &self.htlc,
513 channel_params.channel_type_features(), &broadcaster_delayed_key, &counterparty_revocation_key
517 /// Returns the witness script of the HTLC output in the commitment transaction.
518 pub fn witness_script<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> ScriptBuf {
519 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
520 let broadcaster_keys = channel_params.broadcaster_pubkeys();
521 let counterparty_keys = channel_params.countersignatory_pubkeys();
522 let broadcaster_htlc_key = HtlcKey::from_basepoint(
523 secp, &broadcaster_keys.htlc_basepoint, &self.per_commitment_point
525 let counterparty_htlc_key = HtlcKey::from_basepoint(
526 secp, &counterparty_keys.htlc_basepoint, &self.per_commitment_point,
528 let counterparty_revocation_key = &RevocationKey::from_basepoint(&secp, &counterparty_keys.revocation_basepoint, &self.per_commitment_point);
529 chan_utils::get_htlc_redeemscript_with_explicit_keys(
530 &self.htlc, channel_params.channel_type_features(), &broadcaster_htlc_key, &counterparty_htlc_key,
531 &counterparty_revocation_key,
535 /// Returns the fully signed witness required to spend the HTLC output in the commitment
537 pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness {
538 chan_utils::build_htlc_input_witness(
539 signature, &self.counterparty_sig, &self.preimage, witness_script,
540 &self.channel_derivation_parameters.transaction_parameters.channel_type_features
544 /// Derives the channel signer required to sign the HTLC input.
545 pub fn derive_channel_signer<S: WriteableEcdsaChannelSigner, SP: Deref>(&self, signer_provider: &SP) -> S
547 SP::Target: SignerProvider<Signer = S>
549 let mut signer = signer_provider.derive_channel_signer(
550 self.channel_derivation_parameters.value_satoshis,
551 self.channel_derivation_parameters.keys_id,
553 signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters);
558 /// A trait to handle Lightning channel key material without concretizing the channel type or
559 /// the signature mechanism.
560 pub trait ChannelSigner {
561 /// Gets the per-commitment point for a specific commitment number
563 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
564 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
566 /// Gets the commitment secret for a specific commitment number as part of the revocation process
568 /// An external signer implementation should error here if the commitment was already signed
569 /// and should refuse to sign it in the future.
571 /// May be called more than once for the same index.
573 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
574 // TODO: return a Result so we can signal a validation error
575 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
577 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
579 /// This is required in order for the signer to make sure that releasing a commitment
580 /// secret won't leave us without a broadcastable holder transaction.
581 /// Policy checks should be implemented in this function, including checking the amount
582 /// sent to us and checking the HTLCs.
584 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
585 /// A validating signer should ensure that an HTLC output is removed only when the matching
586 /// preimage is provided, or when the value to holder is restored.
588 /// Note that all the relevant preimages will be provided, but there may also be additional
589 /// irrelevant or duplicate preimages.
590 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
591 preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
593 /// Returns the holder's channel public keys and basepoints.
594 fn pubkeys(&self) -> &ChannelPublicKeys;
596 /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
597 /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
598 /// [`EcdsaChannelSigner`] object uniquely and lookup or re-derive its keys.
599 fn channel_keys_id(&self) -> [u8; 32];
601 /// Set the counterparty static channel data, including basepoints,
602 /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint.
604 /// This data is static, and will never change for a channel once set. For a given [`ChannelSigner`]
605 /// instance, LDK will call this method exactly once - either immediately after construction
606 /// (not including if done via [`SignerProvider::read_chan_signer`]) or when the funding
607 /// information has been generated.
609 /// channel_parameters.is_populated() MUST be true.
610 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
613 /// A trait to sign Lightning channel transactions as described in
614 /// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
616 /// Signing services could be implemented on a hardware wallet and should implement signing
617 /// policies in order to be secure. Please refer to the [VLS Policy
618 /// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md)
619 /// for an example of such policies.
620 pub trait EcdsaChannelSigner: ChannelSigner {
621 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
623 /// Note that if signing fails or is rejected, the channel will be force-closed.
625 /// Policy checks should be implemented in this function, including checking the amount
626 /// sent to us and checking the HTLCs.
628 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
629 /// A validating signer should ensure that an HTLC output is removed only when the matching
630 /// preimage is provided, or when the value to holder is restored.
632 /// Note that all the relevant preimages will be provided, but there may also be additional
633 /// irrelevant or duplicate preimages.
635 // TODO: Document the things someone using this interface should enforce before signing.
636 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
637 preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
638 ) -> Result<(Signature, Vec<Signature>), ()>;
639 /// Validate the counterparty's revocation.
641 /// This is required in order for the signer to make sure that the state has moved
642 /// forward and it is safe to sign the next counterparty commitment.
643 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
644 /// Creates a signature for a holder's commitment transaction.
646 /// This will be called
647 /// - with a non-revoked `commitment_tx`.
648 /// - with the latest `commitment_tx` when we initiate a force-close.
650 /// This may be called multiple times for the same transaction.
652 /// An external signer implementation should check that the commitment has not been revoked.
654 // TODO: Document the things someone using this interface should enforce before signing.
655 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
656 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
657 /// Same as [`sign_holder_commitment`], but exists only for tests to get access to holder
658 /// commitment transactions which will be broadcasted later, after the channel has moved on to a
659 /// newer state. Thus, needs its own method as [`sign_holder_commitment`] may enforce that we
660 /// only ever get called once.
661 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
662 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
663 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
664 /// Create a signature for the given input in a transaction spending an HTLC transaction output
665 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
667 /// A justice transaction may claim multiple outputs at the same time if timelocks are
668 /// similar, but only a signature for the input at index `input` should be signed for here.
669 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
670 /// to an upcoming timelock expiration.
672 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
674 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
675 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
676 /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do
678 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64,
679 per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>
680 ) -> Result<Signature, ()>;
681 /// Create a signature for the given input in a transaction spending a commitment transaction
682 /// HTLC output when our counterparty broadcasts an old state.
684 /// A justice transaction may claim multiple outputs at the same time if timelocks are
685 /// similar, but only a signature for the input at index `input` should be signed for here.
686 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
687 /// to an upcoming timelock expiration.
689 /// `amount` is the value of the output spent by this input, committed to in the BIP 143
692 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
693 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
694 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
697 /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script
698 /// (which is committed to in the BIP 143 signatures).
699 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64,
700 per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment,
701 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
702 /// Computes the signature for a commitment transaction's HTLC output used as an input within
703 /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned
704 /// must be be computed using [`EcdsaSighashType::All`].
706 /// Note that this may be called for HTLCs in the penultimate commitment transaction if a
707 /// [`ChannelMonitor`] [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas)
708 /// broadcasts it before receiving the update for the latest commitment transaction.
710 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
711 fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize,
712 htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1<secp256k1::All>
713 ) -> Result<Signature, ()>;
714 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
715 /// transaction, either offered or received.
717 /// Such a transaction may claim multiples offered outputs at same time if we know the
718 /// preimage for each when we create it, but only the input at index `input` should be
719 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
720 /// needed with regards to an upcoming timelock expiration.
722 /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
725 /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
727 /// `per_commitment_point` is the dynamic point corresponding to the channel state
728 /// detected onchain. It has been generated by our counterparty and is used to derive
729 /// channel state keys, which are then included in the witness script and committed to in the
730 /// BIP 143 signature.
731 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64,
732 per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment,
733 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
734 /// Create a signature for a (proposed) closing transaction.
736 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
737 /// chosen to forgo their output as dust.
738 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
739 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
740 /// Computes the signature for a commitment transaction's anchor output used as an
741 /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
742 fn sign_holder_anchor_input(
743 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
744 ) -> Result<Signature, ()>;
745 /// Signs a channel announcement message with our funding key proving it comes from one of the
746 /// channel participants.
748 /// Channel announcements also require a signature from each node's network key. Our node
749 /// signature is computed through [`NodeSigner::sign_gossip_message`].
751 /// Note that if this fails or is rejected, the channel will not be publicly announced and
752 /// our counterparty may (though likely will not) close the channel on us for violating the
754 fn sign_channel_announcement_with_funding_key(
755 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
756 ) -> Result<Signature, ()>;
759 /// A writeable signer.
761 /// There will always be two instances of a signer per channel, one occupied by the
762 /// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
764 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
765 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
766 pub trait WriteableEcdsaChannelSigner: EcdsaChannelSigner + Writeable {}
768 /// Specifies the recipient of an invoice.
770 /// This indicates to [`NodeSigner::sign_invoice`] what node secret key should be used to sign
773 /// The invoice should be signed with the local node secret key.
775 /// The invoice should be signed with the phantom node secret key. This secret key must be the
776 /// same for all nodes participating in the [phantom node payment].
778 /// [phantom node payment]: PhantomKeysManager
782 /// A trait that describes a source of entropy.
783 pub trait EntropySource {
784 /// Gets a unique, cryptographically-secure, random 32-byte value. This method must return a
785 /// different value each time it is called.
786 fn get_secure_random_bytes(&self) -> [u8; 32];
789 /// A trait that can handle cryptographic operations at the scope level of a node.
790 pub trait NodeSigner {
791 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
793 /// If the implementor of this trait supports [phantom node payments], then every node that is
794 /// intended to be included in the phantom invoice route hints must return the same value from
796 // This is because LDK avoids storing inbound payment data by encrypting payment data in the
797 // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
798 // nodes, they must share the key that encrypts this payment data.
800 /// This method must return the same value each time it is called.
802 /// [phantom node payments]: PhantomKeysManager
803 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
805 /// Get node id based on the provided [`Recipient`].
807 /// This method must return the same value each time it is called with a given [`Recipient`]
810 /// Errors if the [`Recipient`] variant is not supported by the implementation.
811 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
813 /// Gets the ECDH shared secret of our node secret and `other_key`, multiplying by `tweak` if
814 /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
815 /// secret, though this is less efficient.
817 /// Note that if this fails while attempting to forward an HTLC, LDK will panic. The error
818 /// should be resolved to allow LDK to resume forwarding HTLCs.
820 /// Errors if the [`Recipient`] variant is not supported by the implementation.
821 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
825 /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
826 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
827 /// blindly signing the hash.
829 /// The `hrp_bytes` are ASCII bytes, while the `invoice_data` is base32.
831 /// The secret key used to sign the invoice is dependent on the [`Recipient`].
833 /// Errors if the [`Recipient`] variant is not supported by the implementation.
834 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()>;
836 /// Signs the [`TaggedHash`] of a BOLT 12 invoice request.
838 /// May be called by a function passed to [`UnsignedInvoiceRequest::sign`] where
839 /// `invoice_request` is the callee.
841 /// Implementors may check that the `invoice_request` is expected rather than blindly signing
842 /// the tagged hash. An `Ok` result should sign `invoice_request.tagged_hash().as_digest()` with
843 /// the node's signing key or an ephemeral key to preserve privacy, whichever is associated with
844 /// [`UnsignedInvoiceRequest::payer_id`].
846 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
847 fn sign_bolt12_invoice_request(
848 &self, invoice_request: &UnsignedInvoiceRequest
849 ) -> Result<schnorr::Signature, ()>;
851 /// Signs the [`TaggedHash`] of a BOLT 12 invoice.
853 /// May be called by a function passed to [`UnsignedBolt12Invoice::sign`] where `invoice` is the
856 /// Implementors may check that the `invoice` is expected rather than blindly signing the tagged
857 /// hash. An `Ok` result should sign `invoice.tagged_hash().as_digest()` with the node's signing
858 /// key or an ephemeral key to preserve privacy, whichever is associated with
859 /// [`UnsignedBolt12Invoice::signing_pubkey`].
861 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
862 fn sign_bolt12_invoice(
863 &self, invoice: &UnsignedBolt12Invoice
864 ) -> Result<schnorr::Signature, ()>;
866 /// Sign a gossip message.
868 /// Note that if this fails, LDK may panic and the message will not be broadcast to the network
869 /// or a possible channel counterparty. If LDK panics, the error should be resolved to allow the
870 /// message to be broadcast, as otherwise it may prevent one from receiving funds over the
871 /// corresponding channel.
872 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
875 /// A trait that can return signer instances for individual channels.
876 pub trait SignerProvider {
877 /// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`].
878 type Signer : WriteableEcdsaChannelSigner;
880 /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::Signer`] through
881 /// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow
882 /// implementations of [`SignerProvider`] to maintain a mapping between itself and the generated
883 /// `channel_keys_id`.
885 /// This method must return a different value each time it is called.
886 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
888 /// Derives the private key material backing a `Signer`.
890 /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
891 /// [`SignerProvider::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
892 /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
893 /// [`ChannelSigner::channel_keys_id`].
894 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer;
896 /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream.
897 /// This is only called during deserialization of other objects which contain
898 /// [`WriteableEcdsaChannelSigner`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
899 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
900 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
901 /// you've read all of the provided bytes to ensure no corruption occurred.
903 /// This method is slowly being phased out -- it will only be called when reading objects
904 /// written by LDK versions prior to 0.0.113.
906 /// [`Signer`]: Self::Signer
907 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
908 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
909 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
911 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
913 /// If this function returns an error, this will result in a channel failing to open.
915 /// This method should return a different value each time it is called, to avoid linking
916 /// on-chain funds across channels as controlled to the same user. `channel_keys_id` may be
917 /// used to derive a unique value for each channel.
918 fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()>;
920 /// Get a script pubkey which we will send funds to when closing a channel.
922 /// If this function returns an error, this will result in a channel failing to open or close.
923 /// In the event of a failure when the counterparty is initiating a close, this can result in a
924 /// channel force close.
926 /// This method should return a different value each time it is called, to avoid linking
927 /// on-chain funds across channels as controlled to the same user.
928 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
931 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
933 /// This implementation performs no policy checks and is insufficient by itself as
934 /// a secure external signer.
936 pub struct InMemorySigner {
937 /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
938 /// holder's anchor output in a commitment transaction, if one is present.
939 pub funding_key: SecretKey,
940 /// Holder secret key for blinded revocation pubkey.
941 pub revocation_base_key: SecretKey,
942 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
943 pub payment_key: SecretKey,
944 /// Holder secret key used in an HTLC transaction.
945 pub delayed_payment_base_key: SecretKey,
946 /// Holder HTLC secret key used in commitment transaction HTLC outputs.
947 pub htlc_base_key: SecretKey,
949 pub commitment_seed: [u8; 32],
950 /// Holder public keys and basepoints.
951 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
952 /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
953 channel_parameters: Option<ChannelTransactionParameters>,
954 /// The total value of this channel.
955 channel_value_satoshis: u64,
956 /// Key derivation parameters.
957 channel_keys_id: [u8; 32],
958 /// Seed from which all randomness produced is derived from.
959 rand_bytes_unique_start: [u8; 32],
960 /// Tracks the number of times we've produced randomness to ensure we don't return the same
962 rand_bytes_index: AtomicCounter,
965 impl PartialEq for InMemorySigner {
966 fn eq(&self, other: &Self) -> bool {
967 self.funding_key == other.funding_key &&
968 self.revocation_base_key == other.revocation_base_key &&
969 self.payment_key == other.payment_key &&
970 self.delayed_payment_base_key == other.delayed_payment_base_key &&
971 self.htlc_base_key == other.htlc_base_key &&
972 self.commitment_seed == other.commitment_seed &&
973 self.holder_channel_pubkeys == other.holder_channel_pubkeys &&
974 self.channel_parameters == other.channel_parameters &&
975 self.channel_value_satoshis == other.channel_value_satoshis &&
976 self.channel_keys_id == other.channel_keys_id
980 impl Clone for InMemorySigner {
981 fn clone(&self) -> Self {
983 funding_key: self.funding_key.clone(),
984 revocation_base_key: self.revocation_base_key.clone(),
985 payment_key: self.payment_key.clone(),
986 delayed_payment_base_key: self.delayed_payment_base_key.clone(),
987 htlc_base_key: self.htlc_base_key.clone(),
988 commitment_seed: self.commitment_seed.clone(),
989 holder_channel_pubkeys: self.holder_channel_pubkeys.clone(),
990 channel_parameters: self.channel_parameters.clone(),
991 channel_value_satoshis: self.channel_value_satoshis,
992 channel_keys_id: self.channel_keys_id,
993 rand_bytes_unique_start: self.get_secure_random_bytes(),
994 rand_bytes_index: AtomicCounter::new(),
999 impl InMemorySigner {
1000 /// Creates a new [`InMemorySigner`].
1001 pub fn new<C: Signing>(
1002 secp_ctx: &Secp256k1<C>,
1003 funding_key: SecretKey,
1004 revocation_base_key: SecretKey,
1005 payment_key: SecretKey,
1006 delayed_payment_base_key: SecretKey,
1007 htlc_base_key: SecretKey,
1008 commitment_seed: [u8; 32],
1009 channel_value_satoshis: u64,
1010 channel_keys_id: [u8; 32],
1011 rand_bytes_unique_start: [u8; 32],
1012 ) -> InMemorySigner {
1013 let holder_channel_pubkeys =
1014 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
1015 &payment_key, &delayed_payment_base_key,
1019 revocation_base_key,
1021 delayed_payment_base_key,
1024 channel_value_satoshis,
1025 holder_channel_pubkeys,
1026 channel_parameters: None,
1028 rand_bytes_unique_start,
1029 rand_bytes_index: AtomicCounter::new(),
1033 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
1034 funding_key: &SecretKey,
1035 revocation_base_key: &SecretKey,
1036 payment_key: &SecretKey,
1037 delayed_payment_base_key: &SecretKey,
1038 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
1039 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
1041 funding_pubkey: from_secret(&funding_key),
1042 revocation_basepoint: RevocationBasepoint::from(from_secret(&revocation_base_key)),
1043 payment_point: from_secret(&payment_key),
1044 delayed_payment_basepoint: DelayedPaymentBasepoint::from(from_secret(&delayed_payment_base_key)),
1045 htlc_basepoint: HtlcBasepoint::from(from_secret(&htlc_base_key)),
1049 /// Returns the counterparty's pubkeys.
1051 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1052 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1053 pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> {
1054 self.get_channel_parameters()
1055 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| ¶ms.pubkeys))
1058 /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
1059 /// transactions, i.e., the amount of time that we have to wait to recover our funds if we
1060 /// broadcast a transaction.
1062 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1063 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1064 pub fn counterparty_selected_contest_delay(&self) -> Option<u16> {
1065 self.get_channel_parameters()
1066 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay))
1069 /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
1070 /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
1071 /// if they broadcast a transaction.
1073 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1074 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1075 pub fn holder_selected_contest_delay(&self) -> Option<u16> {
1076 self.get_channel_parameters().map(|params| params.holder_selected_contest_delay)
1079 /// Returns whether the holder is the initiator.
1081 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1082 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1083 pub fn is_outbound(&self) -> Option<bool> {
1084 self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
1087 /// Funding outpoint
1089 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1090 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1091 pub fn funding_outpoint(&self) -> Option<&OutPoint> {
1092 self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
1095 /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
1096 /// building transactions.
1098 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1099 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1100 pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> {
1101 self.channel_parameters.as_ref()
1104 /// Returns the channel type features of the channel parameters. Should be helpful for
1105 /// determining a channel's category, i. e. legacy/anchors/taproot/etc.
1107 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1108 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1109 pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> {
1110 self.get_channel_parameters().map(|params| ¶ms.channel_type_features)
1113 /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
1114 /// by `descriptor`, returning the witness stack for the input.
1116 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1117 /// is not spending the outpoint described by [`descriptor.outpoint`],
1118 /// or if an output descriptor `script_pubkey` does not match the one we can spend.
1120 /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint
1121 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Witness, ()> {
1122 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1123 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1124 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1125 // bindings updates to support SigHashCache objects).
1126 if spend_tx.input.len() <= input_idx { return Err(()); }
1127 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1128 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1130 let remotepubkey = bitcoin::PublicKey::new(self.pubkeys().payment_point);
1131 // We cannot always assume that `channel_parameters` is set, so can't just call
1132 // `self.channel_parameters()` or anything that relies on it
1133 let supports_anchors_zero_fee_htlc_tx = self.channel_type_features()
1134 .map(|features| features.supports_anchors_zero_fee_htlc_tx())
1137 let witness_script = if supports_anchors_zero_fee_htlc_tx {
1138 chan_utils::get_to_countersignatory_with_anchors_redeemscript(&remotepubkey.inner)
1140 ScriptBuf::new_p2pkh(&remotepubkey.pubkey_hash())
1142 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1143 let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self);
1144 let payment_script = if supports_anchors_zero_fee_htlc_tx {
1145 witness_script.to_v0_p2wsh()
1147 ScriptBuf::new_v0_p2wpkh(&remotepubkey.wpubkey_hash().unwrap())
1150 if payment_script != descriptor.output.script_pubkey { return Err(()); }
1152 let mut witness = Vec::with_capacity(2);
1153 witness.push(remotesig.serialize_der().to_vec());
1154 witness[0].push(EcdsaSighashType::All as u8);
1155 if supports_anchors_zero_fee_htlc_tx {
1156 witness.push(witness_script.to_bytes());
1158 witness.push(remotepubkey.to_bytes());
1163 /// Sign the single input of `spend_tx` at index `input_idx` which spends the output
1164 /// described by `descriptor`, returning the witness stack for the input.
1166 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1167 /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
1168 /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
1169 /// `script_pubkey` does not match the one we can spend.
1171 /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
1172 /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
1173 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Witness, ()> {
1174 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1175 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1176 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1177 // bindings updates to support SigHashCache objects).
1178 if spend_tx.input.len() <= input_idx { return Err(()); }
1179 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1180 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1181 if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
1183 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
1184 let delayed_payment_pubkey = DelayedPaymentKey::from_secret_key(&secp_ctx, &delayed_payment_key);
1185 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
1186 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1187 let local_delayedsig = EcdsaSignature {
1188 sig: sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self),
1189 hash_ty: EcdsaSighashType::All,
1191 let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
1193 if descriptor.output.script_pubkey != payment_script { return Err(()); }
1195 Ok(Witness::from_slice(&[
1196 &local_delayedsig.serialize()[..],
1198 witness_script.as_bytes(),
1203 impl EntropySource for InMemorySigner {
1204 fn get_secure_random_bytes(&self) -> [u8; 32] {
1205 let index = self.rand_bytes_index.get_increment();
1206 let mut nonce = [0u8; 16];
1207 nonce[..8].copy_from_slice(&index.to_be_bytes());
1208 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1212 impl ChannelSigner for InMemorySigner {
1213 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
1214 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
1215 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
1218 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
1219 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
1222 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
1226 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
1228 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
1230 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
1231 assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
1232 if self.channel_parameters.is_some() {
1233 // The channel parameters were already set and they match, return early.
1236 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
1237 self.channel_parameters = Some(channel_parameters.clone());
1241 const MISSING_PARAMS_ERR: &'static str = "ChannelSigner::provide_channel_parameters must be called before signing operations";
1243 impl EcdsaChannelSigner for InMemorySigner {
1244 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
1245 let trusted_tx = commitment_tx.trust();
1246 let keys = trusted_tx.keys();
1248 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1249 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1250 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1252 let built_tx = trusted_tx.built_transaction();
1253 let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
1254 let commitment_txid = built_tx.txid;
1256 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
1257 for htlc in commitment_tx.htlcs() {
1258 let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
1259 let holder_selected_contest_delay =
1260 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1261 let chan_type = &channel_parameters.channel_type_features;
1262 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);
1263 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, chan_type, &keys);
1264 let htlc_sighashtype = if chan_type.supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
1265 let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
1266 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
1267 htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
1270 Ok((commitment_sig, htlc_sigs))
1273 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
1277 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1278 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1279 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1280 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1281 let trusted_tx = commitment_tx.trust();
1282 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1285 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1286 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1287 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1288 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1289 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1290 let trusted_tx = commitment_tx.trust();
1291 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1294 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1295 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1296 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1297 let revocation_pubkey = RevocationKey::from_basepoint(
1298 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1300 let witness_script = {
1301 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1302 let holder_selected_contest_delay =
1303 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1304 let counterparty_delayedpubkey = DelayedPaymentKey::from_basepoint(&secp_ctx, &counterparty_keys.delayed_payment_basepoint, &per_commitment_point);
1305 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, holder_selected_contest_delay, &counterparty_delayedpubkey)
1307 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1308 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1309 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1312 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, ()> {
1313 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1314 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1315 let revocation_pubkey = RevocationKey::from_basepoint(
1316 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1318 let witness_script = {
1319 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1320 let counterparty_htlcpubkey = HtlcKey::from_basepoint(
1321 &secp_ctx, &counterparty_keys.htlc_basepoint, &per_commitment_point,
1323 let holder_htlcpubkey = HtlcKey::from_basepoint(
1324 &secp_ctx, &self.pubkeys().htlc_basepoint, &per_commitment_point,
1326 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1327 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
1329 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1330 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1331 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1334 fn sign_holder_htlc_transaction(
1335 &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
1336 secp_ctx: &Secp256k1<secp256k1::All>
1337 ) -> Result<Signature, ()> {
1338 let witness_script = htlc_descriptor.witness_script(secp_ctx);
1339 let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
1340 input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
1342 let our_htlc_private_key = chan_utils::derive_private_key(
1343 &secp_ctx, &htlc_descriptor.per_commitment_point, &self.htlc_base_key
1345 Ok(sign_with_aux_rand(&secp_ctx, &hash_to_message!(sighash.as_byte_array()), &our_htlc_private_key, &self))
1348 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, ()> {
1349 let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
1350 let revocation_pubkey = RevocationKey::from_basepoint(
1351 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1353 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1354 let counterparty_htlcpubkey = HtlcKey::from_basepoint(
1355 &secp_ctx, &counterparty_keys.htlc_basepoint, &per_commitment_point,
1357 let htlcpubkey = HtlcKey::from_basepoint(&secp_ctx, &self.pubkeys().htlc_basepoint, &per_commitment_point);
1358 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1359 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
1360 let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
1361 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1362 Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self))
1365 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1366 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1367 let counterparty_funding_key = &self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
1368 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, counterparty_funding_key);
1369 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
1372 fn sign_holder_anchor_input(
1373 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
1374 ) -> Result<Signature, ()> {
1375 let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
1376 let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
1377 input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
1379 Ok(sign_with_aux_rand(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key, &self))
1382 fn sign_channel_announcement_with_funding_key(
1383 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
1384 ) -> Result<Signature, ()> {
1385 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1386 Ok(secp_ctx.sign_ecdsa(&msghash, &self.funding_key))
1390 const SERIALIZATION_VERSION: u8 = 1;
1392 const MIN_SERIALIZATION_VERSION: u8 = 1;
1394 impl WriteableEcdsaChannelSigner for InMemorySigner {}
1396 impl Writeable for InMemorySigner {
1397 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
1398 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
1400 self.funding_key.write(writer)?;
1401 self.revocation_base_key.write(writer)?;
1402 self.payment_key.write(writer)?;
1403 self.delayed_payment_base_key.write(writer)?;
1404 self.htlc_base_key.write(writer)?;
1405 self.commitment_seed.write(writer)?;
1406 self.channel_parameters.write(writer)?;
1407 self.channel_value_satoshis.write(writer)?;
1408 self.channel_keys_id.write(writer)?;
1410 write_tlv_fields!(writer, {});
1416 impl<ES: Deref> ReadableArgs<ES> for InMemorySigner where ES::Target: EntropySource {
1417 fn read<R: io::Read>(reader: &mut R, entropy_source: ES) -> Result<Self, DecodeError> {
1418 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
1420 let funding_key = Readable::read(reader)?;
1421 let revocation_base_key = Readable::read(reader)?;
1422 let payment_key = Readable::read(reader)?;
1423 let delayed_payment_base_key = Readable::read(reader)?;
1424 let htlc_base_key = Readable::read(reader)?;
1425 let commitment_seed = Readable::read(reader)?;
1426 let counterparty_channel_data = Readable::read(reader)?;
1427 let channel_value_satoshis = Readable::read(reader)?;
1428 let secp_ctx = Secp256k1::signing_only();
1429 let holder_channel_pubkeys =
1430 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
1431 &payment_key, &delayed_payment_base_key, &htlc_base_key);
1432 let keys_id = Readable::read(reader)?;
1434 read_tlv_fields!(reader, {});
1438 revocation_base_key,
1440 delayed_payment_base_key,
1443 channel_value_satoshis,
1444 holder_channel_pubkeys,
1445 channel_parameters: counterparty_channel_data,
1446 channel_keys_id: keys_id,
1447 rand_bytes_unique_start: entropy_source.get_secure_random_bytes(),
1448 rand_bytes_index: AtomicCounter::new(),
1453 /// Simple implementation of [`EntropySource`], [`NodeSigner`], and [`SignerProvider`] that takes a
1454 /// 32-byte seed for use as a BIP 32 extended key and derives keys from that.
1456 /// Your `node_id` is seed/0'.
1457 /// Unilateral closes may use seed/1'.
1458 /// Cooperative closes may use seed/2'.
1459 /// The two close keys may be needed to claim on-chain funds!
1461 /// This struct cannot be used for nodes that wish to support receiving phantom payments;
1462 /// [`PhantomKeysManager`] must be used instead.
1464 /// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
1465 /// previously issued invoices and attempts to pay previous invoices will fail.
1466 pub struct KeysManager {
1467 secp_ctx: Secp256k1<secp256k1::All>,
1468 node_secret: SecretKey,
1470 inbound_payment_key: KeyMaterial,
1471 destination_script: ScriptBuf,
1472 shutdown_pubkey: PublicKey,
1473 channel_master_key: ExtendedPrivKey,
1474 channel_child_index: AtomicUsize,
1476 rand_bytes_unique_start: [u8; 32],
1477 rand_bytes_index: AtomicCounter,
1480 starting_time_secs: u64,
1481 starting_time_nanos: u32,
1485 /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
1486 /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
1487 /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
1488 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
1489 /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
1490 /// is to simply use the current time (with very high precision).
1492 /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
1493 /// obviously, `starting_time` should be unique every time you reload the library - it is only
1494 /// used to generate new ephemeral key data (which will be stored by the individual channel if
1497 /// Note that the seed is required to recover certain on-chain funds independent of
1498 /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
1499 /// for any channel, and some on-chain during-closing funds.
1501 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
1502 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
1503 let secp_ctx = Secp256k1::new();
1504 // Note that when we aren't serializing the key, network doesn't matter
1505 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
1507 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key;
1508 let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret);
1509 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
1510 Ok(destination_key) => {
1511 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
1512 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1513 .push_slice(&wpubkey_hash.to_byte_array())
1516 Err(_) => panic!("Your RNG is busted"),
1518 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
1519 Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key,
1520 Err(_) => panic!("Your RNG is busted"),
1522 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
1523 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key;
1524 let mut inbound_pmt_key_bytes = [0; 32];
1525 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
1527 let mut rand_bytes_engine = Sha256::engine();
1528 rand_bytes_engine.input(&starting_time_secs.to_be_bytes());
1529 rand_bytes_engine.input(&starting_time_nanos.to_be_bytes());
1530 rand_bytes_engine.input(seed);
1531 rand_bytes_engine.input(b"LDK PRNG Seed");
1532 let rand_bytes_unique_start = Sha256::from_engine(rand_bytes_engine).to_byte_array();
1534 let mut res = KeysManager {
1538 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
1544 channel_child_index: AtomicUsize::new(0),
1546 rand_bytes_unique_start,
1547 rand_bytes_index: AtomicCounter::new(),
1551 starting_time_nanos,
1553 let secp_seed = res.get_secure_random_bytes();
1554 res.secp_ctx.seeded_randomize(&secp_seed);
1557 Err(_) => panic!("Your rng is busted"),
1561 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1562 pub fn get_node_secret_key(&self) -> SecretKey {
1566 /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters.
1567 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1568 let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
1569 let mut unique_start = Sha256::engine();
1570 unique_start.input(params);
1571 unique_start.input(&self.seed);
1573 // We only seriously intend to rely on the channel_master_key for true secure
1574 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
1575 // starting_time provided in the constructor) to be unique.
1576 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx,
1577 ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted")
1578 ).expect("Your RNG is busted");
1579 unique_start.input(&child_privkey.private_key[..]);
1581 let seed = Sha256::from_engine(unique_start).to_byte_array();
1583 let commitment_seed = {
1584 let mut sha = Sha256::engine();
1586 sha.input(&b"commitment seed"[..]);
1587 Sha256::from_engine(sha).to_byte_array()
1589 macro_rules! key_step {
1590 ($info: expr, $prev_key: expr) => {{
1591 let mut sha = Sha256::engine();
1593 sha.input(&$prev_key[..]);
1594 sha.input(&$info[..]);
1595 SecretKey::from_slice(&Sha256::from_engine(sha).to_byte_array()).expect("SHA-256 is busted")
1598 let funding_key = key_step!(b"funding key", commitment_seed);
1599 let revocation_base_key = key_step!(b"revocation base key", funding_key);
1600 let payment_key = key_step!(b"payment key", revocation_base_key);
1601 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
1602 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
1603 let prng_seed = self.get_secure_random_bytes();
1605 InMemorySigner::new(
1608 revocation_base_key,
1610 delayed_payment_base_key,
1613 channel_value_satoshis,
1619 /// Signs the given [`PartiallySignedTransaction`] which spends the given [`SpendableOutputDescriptor`]s.
1620 /// The resulting inputs will be finalized and the PSBT will be ready for broadcast if there
1621 /// are no other inputs that need signing.
1623 /// Returns `Err(())` if the PSBT is missing a descriptor or if we fail to sign.
1625 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1626 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1627 pub fn sign_spendable_outputs_psbt<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], mut psbt: PartiallySignedTransaction, secp_ctx: &Secp256k1<C>) -> Result<PartiallySignedTransaction, ()> {
1628 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
1629 for outp in descriptors {
1631 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1632 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1633 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1634 let mut signer = self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id);
1635 if let Some(channel_params) = descriptor.channel_transaction_parameters.as_ref() {
1636 signer.provide_channel_parameters(channel_params);
1638 keys_cache = Some((signer, descriptor.channel_keys_id));
1640 let witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?;
1641 psbt.inputs[input_idx].final_script_witness = Some(witness);
1643 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1644 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1645 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1647 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1648 descriptor.channel_keys_id));
1650 let witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?;
1651 psbt.inputs[input_idx].final_script_witness = Some(witness);
1653 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output, .. } => {
1654 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == outpoint.into_bitcoin_outpoint()).ok_or(())?;
1655 let derivation_idx = if output.script_pubkey == self.destination_script {
1661 // Note that when we aren't serializing the key, network doesn't matter
1662 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1664 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1666 Err(_) => panic!("Your RNG is busted"),
1669 Err(_) => panic!("Your rng is busted"),
1672 let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
1673 if derivation_idx == 2 {
1674 assert_eq!(pubkey.inner, self.shutdown_pubkey);
1676 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1677 let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey();
1679 if payment_script != output.script_pubkey { return Err(()); };
1681 let sighash = hash_to_message!(&sighash::SighashCache::new(&psbt.unsigned_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
1682 let sig = sign_with_aux_rand(secp_ctx, &sighash, &secret.private_key, &self);
1683 let mut sig_ser = sig.serialize_der().to_vec();
1684 sig_ser.push(EcdsaSighashType::All as u8);
1685 let witness = Witness::from_slice(&[&sig_ser, &pubkey.inner.serialize().to_vec()]);
1686 psbt.inputs[input_idx].final_script_witness = Some(witness);
1694 /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
1695 /// output to the given change destination (if sufficient change value remains). The
1696 /// transaction will have a feerate, at least, of the given value.
1698 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
1699 /// transaction will have a locktime of 0. It it recommended to set this to the current block
1700 /// height to avoid fee sniping, unless you have some specific reason to use a different
1703 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
1704 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
1705 /// does not match the one we can spend.
1707 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
1709 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1710 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1711 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1712 let (mut psbt, expected_max_weight) = SpendableOutputDescriptor::create_spendable_outputs_psbt(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime)?;
1713 psbt = self.sign_spendable_outputs_psbt(descriptors, psbt, secp_ctx)?;
1715 let spend_tx = psbt.extract_tx();
1717 debug_assert!(expected_max_weight >= spend_tx.weight().to_wu());
1718 // Note that witnesses with a signature vary somewhat in size, so allow
1719 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1720 debug_assert!(expected_max_weight <= spend_tx.weight().to_wu() + descriptors.len() as u64 * 3);
1726 impl EntropySource for KeysManager {
1727 fn get_secure_random_bytes(&self) -> [u8; 32] {
1728 let index = self.rand_bytes_index.get_increment();
1729 let mut nonce = [0u8; 16];
1730 nonce[..8].copy_from_slice(&index.to_be_bytes());
1731 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1735 impl NodeSigner for KeysManager {
1736 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1738 Recipient::Node => Ok(self.node_id.clone()),
1739 Recipient::PhantomNode => Err(())
1743 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1744 let mut node_secret = match recipient {
1745 Recipient::Node => Ok(self.node_secret.clone()),
1746 Recipient::PhantomNode => Err(())
1748 if let Some(tweak) = tweak {
1749 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1751 Ok(SharedSecret::new(other_key, &node_secret))
1754 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1755 self.inbound_payment_key.clone()
1758 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1759 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1760 let secret = match recipient {
1761 Recipient::Node => Ok(&self.node_secret),
1762 Recipient::PhantomNode => Err(())
1764 Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), secret))
1767 fn sign_bolt12_invoice_request(
1768 &self, invoice_request: &UnsignedInvoiceRequest
1769 ) -> Result<schnorr::Signature, ()> {
1770 let message = invoice_request.tagged_hash().as_digest();
1771 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1772 let aux_rand = self.get_secure_random_bytes();
1773 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1776 fn sign_bolt12_invoice(
1777 &self, invoice: &UnsignedBolt12Invoice
1778 ) -> Result<schnorr::Signature, ()> {
1779 let message = invoice.tagged_hash().as_digest();
1780 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1781 let aux_rand = self.get_secure_random_bytes();
1782 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1785 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1786 let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1787 Ok(self.secp_ctx.sign_ecdsa(&msg_hash, &self.node_secret))
1791 impl SignerProvider for KeysManager {
1792 type Signer = InMemorySigner;
1794 fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1795 let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1796 // `child_idx` is the only thing guaranteed to make each channel unique without a restart
1797 // (though `user_channel_id` should help, depending on user behavior). If it manages to
1798 // roll over, we may generate duplicate keys for two different channels, which could result
1799 // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
1800 // doesn't reach `u32::MAX`.
1801 assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
1802 let mut id = [0; 32];
1803 id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
1804 id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
1805 id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
1806 id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
1810 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1811 self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
1814 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1815 InMemorySigner::read(&mut io::Cursor::new(reader), self)
1818 fn get_destination_script(&self, _channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
1819 Ok(self.destination_script.clone())
1822 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1823 Ok(ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone()))
1827 /// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
1830 /// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
1831 /// paid to one of multiple nodes. This works because we encode the invoice route hints such that
1832 /// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
1833 /// itself without ever needing to forward to this fake node.
1835 /// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
1836 /// provide some fault tolerance, because payers will automatically retry paying other provided
1837 /// nodes in the case that one node goes down.
1839 /// Note that multi-path payments are not supported in phantom invoices for security reasons.
1840 // In the hypothetical case that we did support MPP phantom payments, there would be no way for
1841 // nodes to know when the full payment has been received (and the preimage can be released) without
1842 // significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
1843 // to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
1844 // is released too early.
1846 /// Switching between this struct and [`KeysManager`] will invalidate any previously issued
1847 /// invoices and attempts to pay previous invoices will fail.
1848 pub struct PhantomKeysManager {
1850 inbound_payment_key: KeyMaterial,
1851 phantom_secret: SecretKey,
1852 phantom_node_id: PublicKey,
1855 impl EntropySource for PhantomKeysManager {
1856 fn get_secure_random_bytes(&self) -> [u8; 32] {
1857 self.inner.get_secure_random_bytes()
1861 impl NodeSigner for PhantomKeysManager {
1862 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1864 Recipient::Node => self.inner.get_node_id(Recipient::Node),
1865 Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
1869 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1870 let mut node_secret = match recipient {
1871 Recipient::Node => self.inner.node_secret.clone(),
1872 Recipient::PhantomNode => self.phantom_secret.clone(),
1874 if let Some(tweak) = tweak {
1875 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1877 Ok(SharedSecret::new(other_key, &node_secret))
1880 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1881 self.inbound_payment_key.clone()
1884 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1885 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1886 let secret = match recipient {
1887 Recipient::Node => &self.inner.node_secret,
1888 Recipient::PhantomNode => &self.phantom_secret,
1890 Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), secret))
1893 fn sign_bolt12_invoice_request(
1894 &self, invoice_request: &UnsignedInvoiceRequest
1895 ) -> Result<schnorr::Signature, ()> {
1896 self.inner.sign_bolt12_invoice_request(invoice_request)
1899 fn sign_bolt12_invoice(
1900 &self, invoice: &UnsignedBolt12Invoice
1901 ) -> Result<schnorr::Signature, ()> {
1902 self.inner.sign_bolt12_invoice(invoice)
1905 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1906 self.inner.sign_gossip_message(msg)
1910 impl SignerProvider for PhantomKeysManager {
1911 type Signer = InMemorySigner;
1913 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1914 self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
1917 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1918 self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
1921 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1922 self.inner.read_chan_signer(reader)
1925 fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
1926 self.inner.get_destination_script(channel_keys_id)
1929 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1930 self.inner.get_shutdown_scriptpubkey()
1934 impl PhantomKeysManager {
1935 /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
1936 /// that is shared across all nodes that intend to participate in [phantom node payments]
1939 /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
1940 /// `starting_time_nanos`.
1942 /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
1943 /// same across restarts, or else inbound payments may fail.
1945 /// [phantom node payments]: PhantomKeysManager
1946 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self {
1947 let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos);
1948 let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed);
1949 let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
1950 let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
1953 inbound_payment_key: KeyMaterial(inbound_key),
1959 /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
1960 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1961 self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime, secp_ctx)
1964 /// See [`KeysManager::derive_channel_keys`] for documentation on this method.
1965 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1966 self.inner.derive_channel_keys(channel_value_satoshis, params)
1969 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1970 pub fn get_node_secret_key(&self) -> SecretKey {
1971 self.inner.get_node_secret_key()
1974 /// Gets the "node_id" secret key of the phantom node used to sign invoices, decode the
1975 /// last-hop onion data, etc.
1976 pub fn get_phantom_node_secret_key(&self) -> SecretKey {
1981 // Ensure that EcdsaChannelSigner can have a vtable
1984 let _signer: Box<dyn EcdsaChannelSigner>;
1989 use std::sync::{Arc, mpsc};
1990 use std::sync::mpsc::TryRecvError;
1992 use std::time::Duration;
1993 use bitcoin::blockdata::constants::genesis_block;
1994 use bitcoin::Network;
1995 use crate::sign::{EntropySource, KeysManager};
1997 use criterion::Criterion;
1999 pub fn bench_get_secure_random_bytes(bench: &mut Criterion) {
2000 let seed = [0u8; 32];
2001 let now = Duration::from_secs(genesis_block(Network::Testnet).header.time as u64);
2002 let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_micros()));
2004 let mut handles = Vec::new();
2005 let mut stops = Vec::new();
2007 let keys_manager_clone = Arc::clone(&keys_manager);
2008 let (stop_sender, stop_receiver) = mpsc::channel();
2009 let handle = thread::spawn(move || {
2011 keys_manager_clone.get_secure_random_bytes();
2012 match stop_receiver.try_recv() {
2013 Ok(_) | Err(TryRecvError::Disconnected) => {
2014 println!("Terminating.");
2017 Err(TryRecvError::Empty) => {}
2021 handles.push(handle);
2022 stops.push(stop_sender);
2025 bench.bench_function("get_secure_random_bytes", |b| b.iter(||
2026 keys_manager.get_secure_random_bytes()));
2029 let _ = stop.send(());
2031 for handle in handles {
2032 handle.join().unwrap();