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.
206 /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
209 /// The witness in the spending input should be:
211 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
214 /// Note that the `nSequence` field in the spending input must be set to
215 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
216 /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
217 /// the outpoint confirms, see [BIP
218 /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
219 /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
222 /// These are generally the result of a "revocable" output to us, spendable only by us unless
223 /// it is an output from an old state which we broadcast (which should never happen).
225 /// To derive the delayed payment key which is used to sign this input, you must pass the
226 /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the
227 /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`ChannelSigner::pubkeys`]) and the provided
228 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The DelayedPaymentKey can be
229 /// generated without the secret key using [`DelayedPaymentKey::from_basepoint`] and only the
230 /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`].
232 /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
233 /// used in the witness script generation), you must pass the counterparty
234 /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to
235 /// [`ChannelSigner::provide_channel_parameters`]) and the provided
236 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to
237 /// [`RevocationKey`].
239 /// The witness script which is hashed and included in the output `script_pubkey` may be
240 /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
241 /// as explained above), our delayed payment pubkey (derived as explained above), and the
242 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to
243 /// [`chan_utils::get_revokeable_redeemscript`].
244 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
245 /// An output spendable exclusively by our payment key (i.e., the private key that corresponds
246 /// to the `payment_point` in [`ChannelSigner::pubkeys`]). The output type depends on the
247 /// channel type negotiated.
249 /// On an anchor outputs channel, the witness in the spending input is:
251 /// <BIP 143 signature> <witness script>
254 /// Otherwise, it is:
256 /// <BIP 143 signature> <payment key>
259 /// These are generally the result of our counterparty having broadcast the current state,
260 /// allowing us to claim the non-HTLC-encumbered outputs immediately, or after one confirmation
261 /// in the case of anchor outputs channels.
262 StaticPaymentOutput(StaticPaymentOutputDescriptor),
265 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
266 (0, StaticOutput) => {
267 (0, outpoint, required),
268 (2, output, required),
271 (1, DelayedPaymentOutput),
272 (2, StaticPaymentOutput),
275 impl SpendableOutputDescriptor {
276 /// Turns this into a [`bitcoin::psbt::Input`] which can be used to create a
277 /// [`PartiallySignedTransaction`] which spends the given descriptor.
279 /// Note that this does not include any signatures, just the information required to
280 /// construct the transaction and sign it.
282 /// This is not exported to bindings users as there is no standard serialization for an input.
283 /// See [`Self::create_spendable_outputs_psbt`] instead.
284 pub fn to_psbt_input(&self) -> bitcoin::psbt::Input {
286 SpendableOutputDescriptor::StaticOutput { output, .. } => {
287 // Is a standard P2WPKH, no need for witness script
288 bitcoin::psbt::Input {
289 witness_utxo: Some(output.clone()),
293 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
294 // TODO we could add the witness script as well
295 bitcoin::psbt::Input {
296 witness_utxo: Some(descriptor.output.clone()),
300 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
301 // TODO we could add the witness script as well
302 bitcoin::psbt::Input {
303 witness_utxo: Some(descriptor.output.clone()),
310 /// Creates an unsigned [`PartiallySignedTransaction`] which spends the given descriptors to
311 /// the given outputs, plus an output to the given change destination (if sufficient
312 /// change value remains). The PSBT will have a feerate, at least, of the given value.
314 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
315 /// transaction will have a locktime of 0. It it recommended to set this to the current block
316 /// height to avoid fee sniping, unless you have some specific reason to use a different
319 /// Returns the PSBT and expected max transaction weight.
321 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
322 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
323 /// does not match the one we can spend.
325 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
326 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), ()> {
327 let mut input = Vec::with_capacity(descriptors.len());
328 let mut input_value = 0;
329 let mut witness_weight = 0;
330 let mut output_set = HashSet::with_capacity(descriptors.len());
331 for outp in descriptors {
333 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
334 if !output_set.insert(descriptor.outpoint) { return Err(()); }
336 if descriptor.channel_transaction_parameters.as_ref()
337 .map(|channel_params| channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx())
340 Sequence::from_consensus(1)
345 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
346 script_sig: ScriptBuf::new(),
348 witness: Witness::new(),
350 witness_weight += descriptor.max_witness_length();
351 #[cfg(feature = "grind_signatures")]
352 { witness_weight -= 1; } // Guarantees a low R signature
353 input_value += descriptor.output.value;
355 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
356 if !output_set.insert(descriptor.outpoint) { return Err(()); }
358 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
359 script_sig: ScriptBuf::new(),
360 sequence: Sequence(descriptor.to_self_delay as u32),
361 witness: Witness::new(),
363 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
364 #[cfg(feature = "grind_signatures")]
365 { witness_weight -= 1; } // Guarantees a low R signature
366 input_value += descriptor.output.value;
368 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
369 if !output_set.insert(*outpoint) { return Err(()); }
371 previous_output: outpoint.into_bitcoin_outpoint(),
372 script_sig: ScriptBuf::new(),
373 sequence: Sequence::ZERO,
374 witness: Witness::new(),
376 witness_weight += 1 + 73 + 34;
377 #[cfg(feature = "grind_signatures")]
378 { witness_weight -= 1; } // Guarantees a low R signature
379 input_value += output.value;
382 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
384 let mut tx = Transaction {
386 lock_time: locktime.unwrap_or(LockTime::ZERO),
390 let expected_max_weight =
391 transaction_utils::maybe_add_change_output(&mut tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
393 let psbt_inputs = descriptors.iter().map(|d| d.to_psbt_input()).collect::<Vec<_>>();
394 let psbt = PartiallySignedTransaction {
396 outputs: vec![Default::default(); tx.output.len()],
398 xpub: Default::default(),
400 proprietary: Default::default(),
401 unknown: Default::default(),
403 Ok((psbt, expected_max_weight))
407 /// The parameters required to derive a channel signer via [`SignerProvider`].
408 #[derive(Clone, Debug, PartialEq, Eq)]
409 pub struct ChannelDerivationParameters {
410 /// The value in satoshis of the channel we're attempting to spend the anchor output of.
411 pub value_satoshis: u64,
412 /// The unique identifier to re-derive the signer for the associated channel.
413 pub keys_id: [u8; 32],
414 /// The necessary channel parameters that need to be provided to the re-derived signer through
415 /// [`ChannelSigner::provide_channel_parameters`].
416 pub transaction_parameters: ChannelTransactionParameters,
419 impl_writeable_tlv_based!(ChannelDerivationParameters, {
420 (0, value_satoshis, required),
421 (2, keys_id, required),
422 (4, transaction_parameters, required),
425 /// A descriptor used to sign for a commitment transaction's HTLC output.
426 #[derive(Clone, Debug, PartialEq, Eq)]
427 pub struct HTLCDescriptor {
428 /// The parameters required to derive the signer for the HTLC input.
429 pub channel_derivation_parameters: ChannelDerivationParameters,
430 /// The txid of the commitment transaction in which the HTLC output lives.
431 pub commitment_txid: Txid,
432 /// The number of the commitment transaction in which the HTLC output lives.
433 pub per_commitment_number: u64,
434 /// The key tweak corresponding to the number of the commitment transaction in which the HTLC
435 /// output lives. This tweak is applied to all the basepoints for both parties in the channel to
436 /// arrive at unique keys per commitment.
438 /// See <https://github.com/lightning/bolts/blob/master/03-transactions.md#keys> for more info.
439 pub per_commitment_point: PublicKey,
440 /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs
441 /// originating from a channel supporting anchor outputs, otherwise it is the channel's
442 /// negotiated feerate at the time the commitment transaction was built.
443 pub feerate_per_kw: u32,
444 /// The details of the HTLC as it appears in the commitment transaction.
445 pub htlc: HTLCOutputInCommitment,
446 /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be
448 pub preimage: Option<PaymentPreimage>,
449 /// The counterparty's signature required to spend the HTLC output.
450 pub counterparty_sig: Signature
453 impl_writeable_tlv_based!(HTLCDescriptor, {
454 (0, channel_derivation_parameters, required),
455 (1, feerate_per_kw, (default_value, 0)),
456 (2, commitment_txid, required),
457 (4, per_commitment_number, required),
458 (6, per_commitment_point, required),
460 (10, preimage, option),
461 (12, counterparty_sig, required),
464 impl HTLCDescriptor {
465 /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint
466 /// being spent by the HTLC input in the HTLC transaction.
467 pub fn outpoint(&self) -> bitcoin::OutPoint {
469 txid: self.commitment_txid,
470 vout: self.htlc.transaction_output_index.unwrap(),
474 /// Returns the UTXO to be spent by the HTLC input, which can be obtained via
475 /// [`Self::unsigned_tx_input`].
476 pub fn previous_utxo<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
478 script_pubkey: self.witness_script(secp).to_v0_p2wsh(),
479 value: self.htlc.amount_msat / 1000,
483 /// Returns the unsigned transaction input spending the HTLC output in the commitment
485 pub fn unsigned_tx_input(&self) -> TxIn {
486 chan_utils::build_htlc_input(
487 &self.commitment_txid, &self.htlc, &self.channel_derivation_parameters.transaction_parameters.channel_type_features
491 /// Returns the delayed output created as a result of spending the HTLC output in the commitment
493 pub fn tx_output<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
494 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
495 let broadcaster_keys = channel_params.broadcaster_pubkeys();
496 let counterparty_keys = channel_params.countersignatory_pubkeys();
497 let broadcaster_delayed_key = DelayedPaymentKey::from_basepoint(
498 secp, &broadcaster_keys.delayed_payment_basepoint, &self.per_commitment_point
500 let counterparty_revocation_key = &RevocationKey::from_basepoint(&secp, &counterparty_keys.revocation_basepoint, &self.per_commitment_point);
501 chan_utils::build_htlc_output(
502 self.feerate_per_kw, channel_params.contest_delay(), &self.htlc,
503 channel_params.channel_type_features(), &broadcaster_delayed_key, &counterparty_revocation_key
507 /// Returns the witness script of the HTLC output in the commitment transaction.
508 pub fn witness_script<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> ScriptBuf {
509 let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
510 let broadcaster_keys = channel_params.broadcaster_pubkeys();
511 let counterparty_keys = channel_params.countersignatory_pubkeys();
512 let broadcaster_htlc_key = HtlcKey::from_basepoint(
513 secp, &broadcaster_keys.htlc_basepoint, &self.per_commitment_point
515 let counterparty_htlc_key = HtlcKey::from_basepoint(
516 secp, &counterparty_keys.htlc_basepoint, &self.per_commitment_point,
518 let counterparty_revocation_key = &RevocationKey::from_basepoint(&secp, &counterparty_keys.revocation_basepoint, &self.per_commitment_point);
519 chan_utils::get_htlc_redeemscript_with_explicit_keys(
520 &self.htlc, channel_params.channel_type_features(), &broadcaster_htlc_key, &counterparty_htlc_key,
521 &counterparty_revocation_key,
525 /// Returns the fully signed witness required to spend the HTLC output in the commitment
527 pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness {
528 chan_utils::build_htlc_input_witness(
529 signature, &self.counterparty_sig, &self.preimage, witness_script,
530 &self.channel_derivation_parameters.transaction_parameters.channel_type_features
534 /// Derives the channel signer required to sign the HTLC input.
535 pub fn derive_channel_signer<S: WriteableEcdsaChannelSigner, SP: Deref>(&self, signer_provider: &SP) -> S
537 SP::Target: SignerProvider<EcdsaSigner= S>
539 let mut signer = signer_provider.derive_channel_signer(
540 self.channel_derivation_parameters.value_satoshis,
541 self.channel_derivation_parameters.keys_id,
543 signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters);
548 /// A trait to handle Lightning channel key material without concretizing the channel type or
549 /// the signature mechanism.
550 pub trait ChannelSigner {
551 /// Gets the per-commitment point for a specific commitment number
553 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
554 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
556 /// Gets the commitment secret for a specific commitment number as part of the revocation process
558 /// An external signer implementation should error here if the commitment was already signed
559 /// and should refuse to sign it in the future.
561 /// May be called more than once for the same index.
563 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
564 // TODO: return a Result so we can signal a validation error
565 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
567 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
569 /// This is required in order for the signer to make sure that releasing a commitment
570 /// secret won't leave us without a broadcastable holder transaction.
571 /// Policy checks should be implemented in this function, including checking the amount
572 /// sent to us and checking the HTLCs.
574 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
575 /// A validating signer should ensure that an HTLC output is removed only when the matching
576 /// preimage is provided, or when the value to holder is restored.
578 /// Note that all the relevant preimages will be provided, but there may also be additional
579 /// irrelevant or duplicate preimages.
580 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
581 preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
583 /// Returns the holder's channel public keys and basepoints.
584 fn pubkeys(&self) -> &ChannelPublicKeys;
586 /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
587 /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
588 /// [`EcdsaChannelSigner`] object uniquely and lookup or re-derive its keys.
589 fn channel_keys_id(&self) -> [u8; 32];
591 /// Set the counterparty static channel data, including basepoints,
592 /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint.
594 /// This data is static, and will never change for a channel once set. For a given [`ChannelSigner`]
595 /// instance, LDK will call this method exactly once - either immediately after construction
596 /// (not including if done via [`SignerProvider::read_chan_signer`]) or when the funding
597 /// information has been generated.
599 /// channel_parameters.is_populated() MUST be true.
600 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
603 /// A trait to sign Lightning channel transactions as described in
604 /// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
606 /// Signing services could be implemented on a hardware wallet and should implement signing
607 /// policies in order to be secure. Please refer to the [VLS Policy
608 /// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md)
609 /// for an example of such policies.
610 pub trait EcdsaChannelSigner: ChannelSigner {
611 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
613 /// Note that if signing fails or is rejected, the channel will be force-closed.
615 /// Policy checks should be implemented in this function, including checking the amount
616 /// sent to us and checking the HTLCs.
618 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
619 /// A validating signer should ensure that an HTLC output is removed only when the matching
620 /// preimage is provided, or when the value to holder is restored.
622 /// Note that all the relevant preimages will be provided, but there may also be additional
623 /// irrelevant or duplicate preimages.
625 // TODO: Document the things someone using this interface should enforce before signing.
626 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
627 preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
628 ) -> Result<(Signature, Vec<Signature>), ()>;
629 /// Validate the counterparty's revocation.
631 /// This is required in order for the signer to make sure that the state has moved
632 /// forward and it is safe to sign the next counterparty commitment.
633 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
634 /// Creates a signature for a holder's commitment transaction.
636 /// This will be called
637 /// - with a non-revoked `commitment_tx`.
638 /// - with the latest `commitment_tx` when we initiate a force-close.
640 /// This may be called multiple times for the same transaction.
642 /// An external signer implementation should check that the commitment has not been revoked.
644 // TODO: Document the things someone using this interface should enforce before signing.
645 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
646 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
647 /// Same as [`sign_holder_commitment`], but exists only for tests to get access to holder
648 /// commitment transactions which will be broadcasted later, after the channel has moved on to a
649 /// newer state. Thus, needs its own method as [`sign_holder_commitment`] may enforce that we
650 /// only ever get called once.
651 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
652 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction,
653 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
654 /// Create a signature for the given input in a transaction spending an HTLC transaction output
655 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
657 /// A justice transaction may claim multiple outputs at the same time if timelocks are
658 /// similar, but only a signature for the input at index `input` should be signed for here.
659 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
660 /// to an upcoming timelock expiration.
662 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
664 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
665 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
666 /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do
668 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64,
669 per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>
670 ) -> Result<Signature, ()>;
671 /// Create a signature for the given input in a transaction spending a commitment transaction
672 /// HTLC output when our counterparty broadcasts an old state.
674 /// A justice transaction may claim multiple outputs at the same time if timelocks are
675 /// similar, but only a signature for the input at index `input` should be signed for here.
676 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
677 /// to an upcoming timelock expiration.
679 /// `amount` is the value of the output spent by this input, committed to in the BIP 143
682 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
683 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
684 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
687 /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script
688 /// (which is committed to in the BIP 143 signatures).
689 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64,
690 per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment,
691 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
692 /// Computes the signature for a commitment transaction's HTLC output used as an input within
693 /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned
694 /// must be be computed using [`EcdsaSighashType::All`].
696 /// Note that this may be called for HTLCs in the penultimate commitment transaction if a
697 /// [`ChannelMonitor`] [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas)
698 /// broadcasts it before receiving the update for the latest commitment transaction.
700 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
701 fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize,
702 htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1<secp256k1::All>
703 ) -> Result<Signature, ()>;
704 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
705 /// transaction, either offered or received.
707 /// Such a transaction may claim multiples offered outputs at same time if we know the
708 /// preimage for each when we create it, but only the input at index `input` should be
709 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
710 /// needed with regards to an upcoming timelock expiration.
712 /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
715 /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
717 /// `per_commitment_point` is the dynamic point corresponding to the channel state
718 /// detected onchain. It has been generated by our counterparty and is used to derive
719 /// channel state keys, which are then included in the witness script and committed to in the
720 /// BIP 143 signature.
721 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64,
722 per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment,
723 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
724 /// Create a signature for a (proposed) closing transaction.
726 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
727 /// chosen to forgo their output as dust.
728 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
729 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
730 /// Computes the signature for a commitment transaction's anchor output used as an
731 /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
732 fn sign_holder_anchor_input(
733 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
734 ) -> Result<Signature, ()>;
735 /// Signs a channel announcement message with our funding key proving it comes from one of the
736 /// channel participants.
738 /// Channel announcements also require a signature from each node's network key. Our node
739 /// signature is computed through [`NodeSigner::sign_gossip_message`].
741 /// Note that if this fails or is rejected, the channel will not be publicly announced and
742 /// our counterparty may (though likely will not) close the channel on us for violating the
744 fn sign_channel_announcement_with_funding_key(
745 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
746 ) -> Result<Signature, ()>;
749 /// A writeable signer.
751 /// There will always be two instances of a signer per channel, one occupied by the
752 /// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
754 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
755 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
756 pub trait WriteableEcdsaChannelSigner: EcdsaChannelSigner + Writeable {}
758 /// Specifies the recipient of an invoice.
760 /// This indicates to [`NodeSigner::sign_invoice`] what node secret key should be used to sign
763 /// The invoice should be signed with the local node secret key.
765 /// The invoice should be signed with the phantom node secret key. This secret key must be the
766 /// same for all nodes participating in the [phantom node payment].
768 /// [phantom node payment]: PhantomKeysManager
772 /// A trait that describes a source of entropy.
773 pub trait EntropySource {
774 /// Gets a unique, cryptographically-secure, random 32-byte value. This method must return a
775 /// different value each time it is called.
776 fn get_secure_random_bytes(&self) -> [u8; 32];
779 /// A trait that can handle cryptographic operations at the scope level of a node.
780 pub trait NodeSigner {
781 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
783 /// If the implementor of this trait supports [phantom node payments], then every node that is
784 /// intended to be included in the phantom invoice route hints must return the same value from
786 // This is because LDK avoids storing inbound payment data by encrypting payment data in the
787 // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
788 // nodes, they must share the key that encrypts this payment data.
790 /// This method must return the same value each time it is called.
792 /// [phantom node payments]: PhantomKeysManager
793 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
795 /// Get node id based on the provided [`Recipient`].
797 /// This method must return the same value each time it is called with a given [`Recipient`]
800 /// Errors if the [`Recipient`] variant is not supported by the implementation.
801 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
803 /// Gets the ECDH shared secret of our node secret and `other_key`, multiplying by `tweak` if
804 /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
805 /// secret, though this is less efficient.
807 /// Note that if this fails while attempting to forward an HTLC, LDK will panic. The error
808 /// should be resolved to allow LDK to resume forwarding HTLCs.
810 /// Errors if the [`Recipient`] variant is not supported by the implementation.
811 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
815 /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
816 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
817 /// blindly signing the hash.
819 /// The `hrp_bytes` are ASCII bytes, while the `invoice_data` is base32.
821 /// The secret key used to sign the invoice is dependent on the [`Recipient`].
823 /// Errors if the [`Recipient`] variant is not supported by the implementation.
824 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()>;
826 /// Signs the [`TaggedHash`] of a BOLT 12 invoice request.
828 /// May be called by a function passed to [`UnsignedInvoiceRequest::sign`] where
829 /// `invoice_request` is the callee.
831 /// Implementors may check that the `invoice_request` is expected rather than blindly signing
832 /// the tagged hash. An `Ok` result should sign `invoice_request.tagged_hash().as_digest()` with
833 /// the node's signing key or an ephemeral key to preserve privacy, whichever is associated with
834 /// [`UnsignedInvoiceRequest::payer_id`].
836 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
837 fn sign_bolt12_invoice_request(
838 &self, invoice_request: &UnsignedInvoiceRequest
839 ) -> Result<schnorr::Signature, ()>;
841 /// Signs the [`TaggedHash`] of a BOLT 12 invoice.
843 /// May be called by a function passed to [`UnsignedBolt12Invoice::sign`] where `invoice` is the
846 /// Implementors may check that the `invoice` is expected rather than blindly signing the tagged
847 /// hash. An `Ok` result should sign `invoice.tagged_hash().as_digest()` with the node's signing
848 /// key or an ephemeral key to preserve privacy, whichever is associated with
849 /// [`UnsignedBolt12Invoice::signing_pubkey`].
851 /// [`TaggedHash`]: crate::offers::merkle::TaggedHash
852 fn sign_bolt12_invoice(
853 &self, invoice: &UnsignedBolt12Invoice
854 ) -> Result<schnorr::Signature, ()>;
856 /// Sign a gossip message.
858 /// Note that if this fails, LDK may panic and the message will not be broadcast to the network
859 /// or a possible channel counterparty. If LDK panics, the error should be resolved to allow the
860 /// message to be broadcast, as otherwise it may prevent one from receiving funds over the
861 /// corresponding channel.
862 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
865 /// A trait that can return signer instances for individual channels.
866 pub trait SignerProvider {
867 /// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`].
868 type EcdsaSigner: WriteableEcdsaChannelSigner;
870 /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::EcdsaSigner`] through
871 /// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow
872 /// implementations of [`SignerProvider`] to maintain a mapping between itself and the generated
873 /// `channel_keys_id`.
875 /// This method must return a different value each time it is called.
876 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
878 /// Derives the private key material backing a `Signer`.
880 /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
881 /// [`SignerProvider::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
882 /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
883 /// [`ChannelSigner::channel_keys_id`].
884 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::EcdsaSigner;
886 /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream.
887 /// This is only called during deserialization of other objects which contain
888 /// [`WriteableEcdsaChannelSigner`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
889 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
890 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
891 /// you've read all of the provided bytes to ensure no corruption occurred.
893 /// This method is slowly being phased out -- it will only be called when reading objects
894 /// written by LDK versions prior to 0.0.113.
896 /// [`Signer`]: Self::EcdsaSigner
897 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
898 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
899 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError>;
901 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
903 /// If this function returns an error, this will result in a channel failing to open.
905 /// This method should return a different value each time it is called, to avoid linking
906 /// on-chain funds across channels as controlled to the same user. `channel_keys_id` may be
907 /// used to derive a unique value for each channel.
908 fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()>;
910 /// Get a script pubkey which we will send funds to when closing a channel.
912 /// If this function returns an error, this will result in a channel failing to open or close.
913 /// In the event of a failure when the counterparty is initiating a close, this can result in a
914 /// channel force close.
916 /// This method should return a different value each time it is called, to avoid linking
917 /// on-chain funds across channels as controlled to the same user.
918 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
921 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
923 /// This implementation performs no policy checks and is insufficient by itself as
924 /// a secure external signer.
926 pub struct InMemorySigner {
927 /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
928 /// holder's anchor output in a commitment transaction, if one is present.
929 pub funding_key: SecretKey,
930 /// Holder secret key for blinded revocation pubkey.
931 pub revocation_base_key: SecretKey,
932 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
933 pub payment_key: SecretKey,
934 /// Holder secret key used in an HTLC transaction.
935 pub delayed_payment_base_key: SecretKey,
936 /// Holder HTLC secret key used in commitment transaction HTLC outputs.
937 pub htlc_base_key: SecretKey,
939 pub commitment_seed: [u8; 32],
940 /// Holder public keys and basepoints.
941 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
942 /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
943 channel_parameters: Option<ChannelTransactionParameters>,
944 /// The total value of this channel.
945 channel_value_satoshis: u64,
946 /// Key derivation parameters.
947 channel_keys_id: [u8; 32],
948 /// Seed from which all randomness produced is derived from.
949 rand_bytes_unique_start: [u8; 32],
950 /// Tracks the number of times we've produced randomness to ensure we don't return the same
952 rand_bytes_index: AtomicCounter,
955 impl PartialEq for InMemorySigner {
956 fn eq(&self, other: &Self) -> bool {
957 self.funding_key == other.funding_key &&
958 self.revocation_base_key == other.revocation_base_key &&
959 self.payment_key == other.payment_key &&
960 self.delayed_payment_base_key == other.delayed_payment_base_key &&
961 self.htlc_base_key == other.htlc_base_key &&
962 self.commitment_seed == other.commitment_seed &&
963 self.holder_channel_pubkeys == other.holder_channel_pubkeys &&
964 self.channel_parameters == other.channel_parameters &&
965 self.channel_value_satoshis == other.channel_value_satoshis &&
966 self.channel_keys_id == other.channel_keys_id
970 impl Clone for InMemorySigner {
971 fn clone(&self) -> Self {
973 funding_key: self.funding_key.clone(),
974 revocation_base_key: self.revocation_base_key.clone(),
975 payment_key: self.payment_key.clone(),
976 delayed_payment_base_key: self.delayed_payment_base_key.clone(),
977 htlc_base_key: self.htlc_base_key.clone(),
978 commitment_seed: self.commitment_seed.clone(),
979 holder_channel_pubkeys: self.holder_channel_pubkeys.clone(),
980 channel_parameters: self.channel_parameters.clone(),
981 channel_value_satoshis: self.channel_value_satoshis,
982 channel_keys_id: self.channel_keys_id,
983 rand_bytes_unique_start: self.get_secure_random_bytes(),
984 rand_bytes_index: AtomicCounter::new(),
989 impl InMemorySigner {
990 /// Creates a new [`InMemorySigner`].
991 pub fn new<C: Signing>(
992 secp_ctx: &Secp256k1<C>,
993 funding_key: SecretKey,
994 revocation_base_key: SecretKey,
995 payment_key: SecretKey,
996 delayed_payment_base_key: SecretKey,
997 htlc_base_key: SecretKey,
998 commitment_seed: [u8; 32],
999 channel_value_satoshis: u64,
1000 channel_keys_id: [u8; 32],
1001 rand_bytes_unique_start: [u8; 32],
1002 ) -> InMemorySigner {
1003 let holder_channel_pubkeys =
1004 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
1005 &payment_key, &delayed_payment_base_key,
1009 revocation_base_key,
1011 delayed_payment_base_key,
1014 channel_value_satoshis,
1015 holder_channel_pubkeys,
1016 channel_parameters: None,
1018 rand_bytes_unique_start,
1019 rand_bytes_index: AtomicCounter::new(),
1023 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
1024 funding_key: &SecretKey,
1025 revocation_base_key: &SecretKey,
1026 payment_key: &SecretKey,
1027 delayed_payment_base_key: &SecretKey,
1028 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
1029 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
1031 funding_pubkey: from_secret(&funding_key),
1032 revocation_basepoint: RevocationBasepoint::from(from_secret(&revocation_base_key)),
1033 payment_point: from_secret(&payment_key),
1034 delayed_payment_basepoint: DelayedPaymentBasepoint::from(from_secret(&delayed_payment_base_key)),
1035 htlc_basepoint: HtlcBasepoint::from(from_secret(&htlc_base_key)),
1039 /// Returns the counterparty's pubkeys.
1041 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1042 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1043 pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> {
1044 self.get_channel_parameters()
1045 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| ¶ms.pubkeys))
1048 /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
1049 /// transactions, i.e., the amount of time that we have to wait to recover our funds if we
1050 /// broadcast a transaction.
1052 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1053 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1054 pub fn counterparty_selected_contest_delay(&self) -> Option<u16> {
1055 self.get_channel_parameters()
1056 .and_then(|params| params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay))
1059 /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
1060 /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
1061 /// if they broadcast a transaction.
1063 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1064 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1065 pub fn holder_selected_contest_delay(&self) -> Option<u16> {
1066 self.get_channel_parameters().map(|params| params.holder_selected_contest_delay)
1069 /// Returns whether the holder is the initiator.
1071 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1072 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1073 pub fn is_outbound(&self) -> Option<bool> {
1074 self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
1077 /// Funding outpoint
1079 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1080 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1081 pub fn funding_outpoint(&self) -> Option<&OutPoint> {
1082 self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
1085 /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
1086 /// building transactions.
1088 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1089 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1090 pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> {
1091 self.channel_parameters.as_ref()
1094 /// Returns the channel type features of the channel parameters. Should be helpful for
1095 /// determining a channel's category, i. e. legacy/anchors/taproot/etc.
1097 /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
1098 /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
1099 pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> {
1100 self.get_channel_parameters().map(|params| ¶ms.channel_type_features)
1103 /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
1104 /// by `descriptor`, returning the witness stack for the input.
1106 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1107 /// is not spending the outpoint described by [`descriptor.outpoint`],
1108 /// or if an output descriptor `script_pubkey` does not match the one we can spend.
1110 /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint
1111 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Witness, ()> {
1112 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1113 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1114 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1115 // bindings updates to support SigHashCache objects).
1116 if spend_tx.input.len() <= input_idx { return Err(()); }
1117 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1118 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1120 let remotepubkey = bitcoin::PublicKey::new(self.pubkeys().payment_point);
1121 // We cannot always assume that `channel_parameters` is set, so can't just call
1122 // `self.channel_parameters()` or anything that relies on it
1123 let supports_anchors_zero_fee_htlc_tx = self.channel_type_features()
1124 .map(|features| features.supports_anchors_zero_fee_htlc_tx())
1127 let witness_script = if supports_anchors_zero_fee_htlc_tx {
1128 chan_utils::get_to_countersignatory_with_anchors_redeemscript(&remotepubkey.inner)
1130 ScriptBuf::new_p2pkh(&remotepubkey.pubkey_hash())
1132 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1133 let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self);
1134 let payment_script = if supports_anchors_zero_fee_htlc_tx {
1135 witness_script.to_v0_p2wsh()
1137 ScriptBuf::new_v0_p2wpkh(&remotepubkey.wpubkey_hash().unwrap())
1140 if payment_script != descriptor.output.script_pubkey { return Err(()); }
1142 let mut witness = Vec::with_capacity(2);
1143 witness.push(remotesig.serialize_der().to_vec());
1144 witness[0].push(EcdsaSighashType::All as u8);
1145 if supports_anchors_zero_fee_htlc_tx {
1146 witness.push(witness_script.to_bytes());
1148 witness.push(remotepubkey.to_bytes());
1153 /// Sign the single input of `spend_tx` at index `input_idx` which spends the output
1154 /// described by `descriptor`, returning the witness stack for the input.
1156 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
1157 /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
1158 /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
1159 /// `script_pubkey` does not match the one we can spend.
1161 /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
1162 /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
1163 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Witness, ()> {
1164 // TODO: We really should be taking the SigHashCache as a parameter here instead of
1165 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
1166 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
1167 // bindings updates to support SigHashCache objects).
1168 if spend_tx.input.len() <= input_idx { return Err(()); }
1169 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
1170 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
1171 if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
1173 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
1174 let delayed_payment_pubkey = DelayedPaymentKey::from_secret_key(&secp_ctx, &delayed_payment_key);
1175 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
1176 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
1177 let local_delayedsig = EcdsaSignature {
1178 sig: sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self),
1179 hash_ty: EcdsaSighashType::All,
1181 let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
1183 if descriptor.output.script_pubkey != payment_script { return Err(()); }
1185 Ok(Witness::from_slice(&[
1186 &local_delayedsig.serialize()[..],
1188 witness_script.as_bytes(),
1193 impl EntropySource for InMemorySigner {
1194 fn get_secure_random_bytes(&self) -> [u8; 32] {
1195 let index = self.rand_bytes_index.get_increment();
1196 let mut nonce = [0u8; 16];
1197 nonce[..8].copy_from_slice(&index.to_be_bytes());
1198 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1202 impl ChannelSigner for InMemorySigner {
1203 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
1204 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
1205 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
1208 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
1209 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
1212 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
1216 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
1218 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
1220 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
1221 assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
1222 if self.channel_parameters.is_some() {
1223 // The channel parameters were already set and they match, return early.
1226 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
1227 self.channel_parameters = Some(channel_parameters.clone());
1231 const MISSING_PARAMS_ERR: &'static str = "ChannelSigner::provide_channel_parameters must be called before signing operations";
1233 impl EcdsaChannelSigner for InMemorySigner {
1234 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
1235 let trusted_tx = commitment_tx.trust();
1236 let keys = trusted_tx.keys();
1238 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1239 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1240 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1242 let built_tx = trusted_tx.built_transaction();
1243 let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
1244 let commitment_txid = built_tx.txid;
1246 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
1247 for htlc in commitment_tx.htlcs() {
1248 let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
1249 let holder_selected_contest_delay =
1250 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1251 let chan_type = &channel_parameters.channel_type_features;
1252 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);
1253 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, chan_type, &keys);
1254 let htlc_sighashtype = if chan_type.supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
1255 let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
1256 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
1257 htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
1260 Ok((commitment_sig, htlc_sigs))
1263 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
1267 fn sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1268 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1269 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1270 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1271 let trusted_tx = commitment_tx.trust();
1272 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1275 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1276 fn unsafe_sign_holder_commitment(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1277 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1278 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1279 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
1280 let trusted_tx = commitment_tx.trust();
1281 Ok(trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx))
1284 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1285 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1286 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1287 let revocation_pubkey = RevocationKey::from_basepoint(
1288 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1290 let witness_script = {
1291 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1292 let holder_selected_contest_delay =
1293 self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
1294 let counterparty_delayedpubkey = DelayedPaymentKey::from_basepoint(&secp_ctx, &counterparty_keys.delayed_payment_basepoint, &per_commitment_point);
1295 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, holder_selected_contest_delay, &counterparty_delayedpubkey)
1297 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1298 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1299 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1302 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, ()> {
1303 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
1304 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
1305 let revocation_pubkey = RevocationKey::from_basepoint(
1306 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1308 let witness_script = {
1309 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1310 let counterparty_htlcpubkey = HtlcKey::from_basepoint(
1311 &secp_ctx, &counterparty_keys.htlc_basepoint, &per_commitment_point,
1313 let holder_htlcpubkey = HtlcKey::from_basepoint(
1314 &secp_ctx, &self.pubkeys().htlc_basepoint, &per_commitment_point,
1316 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1317 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
1319 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
1320 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1321 return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
1324 fn sign_holder_htlc_transaction(
1325 &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
1326 secp_ctx: &Secp256k1<secp256k1::All>
1327 ) -> Result<Signature, ()> {
1328 let witness_script = htlc_descriptor.witness_script(secp_ctx);
1329 let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
1330 input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
1332 let our_htlc_private_key = chan_utils::derive_private_key(
1333 &secp_ctx, &htlc_descriptor.per_commitment_point, &self.htlc_base_key
1335 Ok(sign_with_aux_rand(&secp_ctx, &hash_to_message!(sighash.as_byte_array()), &our_htlc_private_key, &self))
1338 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, ()> {
1339 let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
1340 let revocation_pubkey = RevocationKey::from_basepoint(
1341 &secp_ctx, &self.pubkeys().revocation_basepoint, &per_commitment_point,
1343 let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
1344 let counterparty_htlcpubkey = HtlcKey::from_basepoint(
1345 &secp_ctx, &counterparty_keys.htlc_basepoint, &per_commitment_point,
1347 let htlcpubkey = HtlcKey::from_basepoint(&secp_ctx, &self.pubkeys().htlc_basepoint, &per_commitment_point);
1348 let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
1349 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
1350 let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
1351 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
1352 Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self))
1355 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
1356 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
1357 let counterparty_funding_key = &self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
1358 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, counterparty_funding_key);
1359 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
1362 fn sign_holder_anchor_input(
1363 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
1364 ) -> Result<Signature, ()> {
1365 let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
1366 let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
1367 input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
1369 Ok(sign_with_aux_rand(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key, &self))
1372 fn sign_channel_announcement_with_funding_key(
1373 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
1374 ) -> Result<Signature, ()> {
1375 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1376 Ok(secp_ctx.sign_ecdsa(&msghash, &self.funding_key))
1380 const SERIALIZATION_VERSION: u8 = 1;
1382 const MIN_SERIALIZATION_VERSION: u8 = 1;
1384 impl WriteableEcdsaChannelSigner for InMemorySigner {}
1386 impl Writeable for InMemorySigner {
1387 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
1388 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
1390 self.funding_key.write(writer)?;
1391 self.revocation_base_key.write(writer)?;
1392 self.payment_key.write(writer)?;
1393 self.delayed_payment_base_key.write(writer)?;
1394 self.htlc_base_key.write(writer)?;
1395 self.commitment_seed.write(writer)?;
1396 self.channel_parameters.write(writer)?;
1397 self.channel_value_satoshis.write(writer)?;
1398 self.channel_keys_id.write(writer)?;
1400 write_tlv_fields!(writer, {});
1406 impl<ES: Deref> ReadableArgs<ES> for InMemorySigner where ES::Target: EntropySource {
1407 fn read<R: io::Read>(reader: &mut R, entropy_source: ES) -> Result<Self, DecodeError> {
1408 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
1410 let funding_key = Readable::read(reader)?;
1411 let revocation_base_key = Readable::read(reader)?;
1412 let payment_key = Readable::read(reader)?;
1413 let delayed_payment_base_key = Readable::read(reader)?;
1414 let htlc_base_key = Readable::read(reader)?;
1415 let commitment_seed = Readable::read(reader)?;
1416 let counterparty_channel_data = Readable::read(reader)?;
1417 let channel_value_satoshis = Readable::read(reader)?;
1418 let secp_ctx = Secp256k1::signing_only();
1419 let holder_channel_pubkeys =
1420 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
1421 &payment_key, &delayed_payment_base_key, &htlc_base_key);
1422 let keys_id = Readable::read(reader)?;
1424 read_tlv_fields!(reader, {});
1428 revocation_base_key,
1430 delayed_payment_base_key,
1433 channel_value_satoshis,
1434 holder_channel_pubkeys,
1435 channel_parameters: counterparty_channel_data,
1436 channel_keys_id: keys_id,
1437 rand_bytes_unique_start: entropy_source.get_secure_random_bytes(),
1438 rand_bytes_index: AtomicCounter::new(),
1443 /// Simple implementation of [`EntropySource`], [`NodeSigner`], and [`SignerProvider`] that takes a
1444 /// 32-byte seed for use as a BIP 32 extended key and derives keys from that.
1446 /// Your `node_id` is seed/0'.
1447 /// Unilateral closes may use seed/1'.
1448 /// Cooperative closes may use seed/2'.
1449 /// The two close keys may be needed to claim on-chain funds!
1451 /// This struct cannot be used for nodes that wish to support receiving phantom payments;
1452 /// [`PhantomKeysManager`] must be used instead.
1454 /// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
1455 /// previously issued invoices and attempts to pay previous invoices will fail.
1456 pub struct KeysManager {
1457 secp_ctx: Secp256k1<secp256k1::All>,
1458 node_secret: SecretKey,
1460 inbound_payment_key: KeyMaterial,
1461 destination_script: ScriptBuf,
1462 shutdown_pubkey: PublicKey,
1463 channel_master_key: ExtendedPrivKey,
1464 channel_child_index: AtomicUsize,
1466 rand_bytes_unique_start: [u8; 32],
1467 rand_bytes_index: AtomicCounter,
1470 starting_time_secs: u64,
1471 starting_time_nanos: u32,
1475 /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
1476 /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
1477 /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
1478 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
1479 /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
1480 /// is to simply use the current time (with very high precision).
1482 /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
1483 /// obviously, `starting_time` should be unique every time you reload the library - it is only
1484 /// used to generate new ephemeral key data (which will be stored by the individual channel if
1487 /// Note that the seed is required to recover certain on-chain funds independent of
1488 /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
1489 /// for any channel, and some on-chain during-closing funds.
1491 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
1492 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
1493 let secp_ctx = Secp256k1::new();
1494 // Note that when we aren't serializing the key, network doesn't matter
1495 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
1497 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key;
1498 let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret);
1499 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
1500 Ok(destination_key) => {
1501 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
1502 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1503 .push_slice(&wpubkey_hash.to_byte_array())
1506 Err(_) => panic!("Your RNG is busted"),
1508 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
1509 Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key,
1510 Err(_) => panic!("Your RNG is busted"),
1512 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
1513 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key;
1514 let mut inbound_pmt_key_bytes = [0; 32];
1515 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
1517 let mut rand_bytes_engine = Sha256::engine();
1518 rand_bytes_engine.input(&starting_time_secs.to_be_bytes());
1519 rand_bytes_engine.input(&starting_time_nanos.to_be_bytes());
1520 rand_bytes_engine.input(seed);
1521 rand_bytes_engine.input(b"LDK PRNG Seed");
1522 let rand_bytes_unique_start = Sha256::from_engine(rand_bytes_engine).to_byte_array();
1524 let mut res = KeysManager {
1528 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
1534 channel_child_index: AtomicUsize::new(0),
1536 rand_bytes_unique_start,
1537 rand_bytes_index: AtomicCounter::new(),
1541 starting_time_nanos,
1543 let secp_seed = res.get_secure_random_bytes();
1544 res.secp_ctx.seeded_randomize(&secp_seed);
1547 Err(_) => panic!("Your rng is busted"),
1551 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1552 pub fn get_node_secret_key(&self) -> SecretKey {
1556 /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters.
1557 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1558 let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
1559 let mut unique_start = Sha256::engine();
1560 unique_start.input(params);
1561 unique_start.input(&self.seed);
1563 // We only seriously intend to rely on the channel_master_key for true secure
1564 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
1565 // starting_time provided in the constructor) to be unique.
1566 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx,
1567 ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted")
1568 ).expect("Your RNG is busted");
1569 unique_start.input(&child_privkey.private_key[..]);
1571 let seed = Sha256::from_engine(unique_start).to_byte_array();
1573 let commitment_seed = {
1574 let mut sha = Sha256::engine();
1576 sha.input(&b"commitment seed"[..]);
1577 Sha256::from_engine(sha).to_byte_array()
1579 macro_rules! key_step {
1580 ($info: expr, $prev_key: expr) => {{
1581 let mut sha = Sha256::engine();
1583 sha.input(&$prev_key[..]);
1584 sha.input(&$info[..]);
1585 SecretKey::from_slice(&Sha256::from_engine(sha).to_byte_array()).expect("SHA-256 is busted")
1588 let funding_key = key_step!(b"funding key", commitment_seed);
1589 let revocation_base_key = key_step!(b"revocation base key", funding_key);
1590 let payment_key = key_step!(b"payment key", revocation_base_key);
1591 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
1592 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
1593 let prng_seed = self.get_secure_random_bytes();
1595 InMemorySigner::new(
1598 revocation_base_key,
1600 delayed_payment_base_key,
1603 channel_value_satoshis,
1609 /// Signs the given [`PartiallySignedTransaction`] which spends the given [`SpendableOutputDescriptor`]s.
1610 /// The resulting inputs will be finalized and the PSBT will be ready for broadcast if there
1611 /// are no other inputs that need signing.
1613 /// Returns `Err(())` if the PSBT is missing a descriptor or if we fail to sign.
1615 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1616 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1617 pub fn sign_spendable_outputs_psbt<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], mut psbt: PartiallySignedTransaction, secp_ctx: &Secp256k1<C>) -> Result<PartiallySignedTransaction, ()> {
1618 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
1619 for outp in descriptors {
1621 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1622 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1623 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1624 let mut signer = self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id);
1625 if let Some(channel_params) = descriptor.channel_transaction_parameters.as_ref() {
1626 signer.provide_channel_parameters(channel_params);
1628 keys_cache = Some((signer, descriptor.channel_keys_id));
1630 let witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?;
1631 psbt.inputs[input_idx].final_script_witness = Some(witness);
1633 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1634 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?;
1635 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1637 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1638 descriptor.channel_keys_id));
1640 let witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?;
1641 psbt.inputs[input_idx].final_script_witness = Some(witness);
1643 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
1644 let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == outpoint.into_bitcoin_outpoint()).ok_or(())?;
1645 let derivation_idx = if output.script_pubkey == self.destination_script {
1651 // Note that when we aren't serializing the key, network doesn't matter
1652 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1654 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1656 Err(_) => panic!("Your RNG is busted"),
1659 Err(_) => panic!("Your rng is busted"),
1662 let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
1663 if derivation_idx == 2 {
1664 assert_eq!(pubkey.inner, self.shutdown_pubkey);
1666 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1667 let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey();
1669 if payment_script != output.script_pubkey { return Err(()); };
1671 let sighash = hash_to_message!(&sighash::SighashCache::new(&psbt.unsigned_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
1672 let sig = sign_with_aux_rand(secp_ctx, &sighash, &secret.private_key, &self);
1673 let mut sig_ser = sig.serialize_der().to_vec();
1674 sig_ser.push(EcdsaSighashType::All as u8);
1675 let witness = Witness::from_slice(&[&sig_ser, &pubkey.inner.serialize().to_vec()]);
1676 psbt.inputs[input_idx].final_script_witness = Some(witness);
1684 /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
1685 /// output to the given change destination (if sufficient change value remains). The
1686 /// transaction will have a feerate, at least, of the given value.
1688 /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
1689 /// transaction will have a locktime of 0. It it recommended to set this to the current block
1690 /// height to avoid fee sniping, unless you have some specific reason to use a different
1693 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
1694 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
1695 /// does not match the one we can spend.
1697 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
1699 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1700 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1701 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, ()> {
1702 let (mut psbt, expected_max_weight) = SpendableOutputDescriptor::create_spendable_outputs_psbt(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime)?;
1703 psbt = self.sign_spendable_outputs_psbt(descriptors, psbt, secp_ctx)?;
1705 let spend_tx = psbt.extract_tx();
1707 debug_assert!(expected_max_weight >= spend_tx.weight().to_wu());
1708 // Note that witnesses with a signature vary somewhat in size, so allow
1709 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1710 debug_assert!(expected_max_weight <= spend_tx.weight().to_wu() + descriptors.len() as u64 * 3);
1716 impl EntropySource for KeysManager {
1717 fn get_secure_random_bytes(&self) -> [u8; 32] {
1718 let index = self.rand_bytes_index.get_increment();
1719 let mut nonce = [0u8; 16];
1720 nonce[..8].copy_from_slice(&index.to_be_bytes());
1721 ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
1725 impl NodeSigner for KeysManager {
1726 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1728 Recipient::Node => Ok(self.node_id.clone()),
1729 Recipient::PhantomNode => Err(())
1733 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1734 let mut node_secret = match recipient {
1735 Recipient::Node => Ok(self.node_secret.clone()),
1736 Recipient::PhantomNode => Err(())
1738 if let Some(tweak) = tweak {
1739 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1741 Ok(SharedSecret::new(other_key, &node_secret))
1744 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1745 self.inbound_payment_key.clone()
1748 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1749 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1750 let secret = match recipient {
1751 Recipient::Node => Ok(&self.node_secret),
1752 Recipient::PhantomNode => Err(())
1754 Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), secret))
1757 fn sign_bolt12_invoice_request(
1758 &self, invoice_request: &UnsignedInvoiceRequest
1759 ) -> Result<schnorr::Signature, ()> {
1760 let message = invoice_request.tagged_hash().as_digest();
1761 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1762 let aux_rand = self.get_secure_random_bytes();
1763 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1766 fn sign_bolt12_invoice(
1767 &self, invoice: &UnsignedBolt12Invoice
1768 ) -> Result<schnorr::Signature, ()> {
1769 let message = invoice.tagged_hash().as_digest();
1770 let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret);
1771 let aux_rand = self.get_secure_random_bytes();
1772 Ok(self.secp_ctx.sign_schnorr_with_aux_rand(message, &keys, &aux_rand))
1775 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1776 let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1777 Ok(self.secp_ctx.sign_ecdsa(&msg_hash, &self.node_secret))
1781 impl SignerProvider for KeysManager {
1782 type EcdsaSigner = InMemorySigner;
1784 fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1785 let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1786 // `child_idx` is the only thing guaranteed to make each channel unique without a restart
1787 // (though `user_channel_id` should help, depending on user behavior). If it manages to
1788 // roll over, we may generate duplicate keys for two different channels, which could result
1789 // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
1790 // doesn't reach `u32::MAX`.
1791 assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
1792 let mut id = [0; 32];
1793 id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
1794 id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
1795 id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
1796 id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
1800 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::EcdsaSigner {
1801 self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
1804 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError> {
1805 InMemorySigner::read(&mut io::Cursor::new(reader), self)
1808 fn get_destination_script(&self, _channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
1809 Ok(self.destination_script.clone())
1812 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1813 Ok(ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone()))
1817 /// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
1820 /// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
1821 /// paid to one of multiple nodes. This works because we encode the invoice route hints such that
1822 /// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
1823 /// itself without ever needing to forward to this fake node.
1825 /// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
1826 /// provide some fault tolerance, because payers will automatically retry paying other provided
1827 /// nodes in the case that one node goes down.
1829 /// Note that multi-path payments are not supported in phantom invoices for security reasons.
1830 // In the hypothetical case that we did support MPP phantom payments, there would be no way for
1831 // nodes to know when the full payment has been received (and the preimage can be released) without
1832 // significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
1833 // to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
1834 // is released too early.
1836 /// Switching between this struct and [`KeysManager`] will invalidate any previously issued
1837 /// invoices and attempts to pay previous invoices will fail.
1838 pub struct PhantomKeysManager {
1840 inbound_payment_key: KeyMaterial,
1841 phantom_secret: SecretKey,
1842 phantom_node_id: PublicKey,
1845 impl EntropySource for PhantomKeysManager {
1846 fn get_secure_random_bytes(&self) -> [u8; 32] {
1847 self.inner.get_secure_random_bytes()
1851 impl NodeSigner for PhantomKeysManager {
1852 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1854 Recipient::Node => self.inner.get_node_id(Recipient::Node),
1855 Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
1859 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1860 let mut node_secret = match recipient {
1861 Recipient::Node => self.inner.node_secret.clone(),
1862 Recipient::PhantomNode => self.phantom_secret.clone(),
1864 if let Some(tweak) = tweak {
1865 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1867 Ok(SharedSecret::new(other_key, &node_secret))
1870 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1871 self.inbound_payment_key.clone()
1874 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1875 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1876 let secret = match recipient {
1877 Recipient::Node => &self.inner.node_secret,
1878 Recipient::PhantomNode => &self.phantom_secret,
1880 Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), secret))
1883 fn sign_bolt12_invoice_request(
1884 &self, invoice_request: &UnsignedInvoiceRequest
1885 ) -> Result<schnorr::Signature, ()> {
1886 self.inner.sign_bolt12_invoice_request(invoice_request)
1889 fn sign_bolt12_invoice(
1890 &self, invoice: &UnsignedBolt12Invoice
1891 ) -> Result<schnorr::Signature, ()> {
1892 self.inner.sign_bolt12_invoice(invoice)
1895 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1896 self.inner.sign_gossip_message(msg)
1900 impl SignerProvider for PhantomKeysManager {
1901 type EcdsaSigner = InMemorySigner;
1903 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1904 self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
1907 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::EcdsaSigner {
1908 self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
1911 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError> {
1912 self.inner.read_chan_signer(reader)
1915 fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
1916 self.inner.get_destination_script(channel_keys_id)
1919 fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
1920 self.inner.get_shutdown_scriptpubkey()
1924 impl PhantomKeysManager {
1925 /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
1926 /// that is shared across all nodes that intend to participate in [phantom node payments]
1929 /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
1930 /// `starting_time_nanos`.
1932 /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
1933 /// same across restarts, or else inbound payments may fail.
1935 /// [phantom node payments]: PhantomKeysManager
1936 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self {
1937 let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos);
1938 let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed);
1939 let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
1940 let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
1943 inbound_payment_key: KeyMaterial(inbound_key),
1949 /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
1950 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, ()> {
1951 self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, locktime, secp_ctx)
1954 /// See [`KeysManager::derive_channel_keys`] for documentation on this method.
1955 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1956 self.inner.derive_channel_keys(channel_value_satoshis, params)
1959 /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
1960 pub fn get_node_secret_key(&self) -> SecretKey {
1961 self.inner.get_node_secret_key()
1964 /// Gets the "node_id" secret key of the phantom node used to sign invoices, decode the
1965 /// last-hop onion data, etc.
1966 pub fn get_phantom_node_secret_key(&self) -> SecretKey {
1971 // Ensure that EcdsaChannelSigner can have a vtable
1974 let _signer: Box<dyn EcdsaChannelSigner>;
1979 use std::sync::{Arc, mpsc};
1980 use std::sync::mpsc::TryRecvError;
1982 use std::time::Duration;
1983 use bitcoin::blockdata::constants::genesis_block;
1984 use bitcoin::Network;
1985 use crate::sign::{EntropySource, KeysManager};
1987 use criterion::Criterion;
1989 pub fn bench_get_secure_random_bytes(bench: &mut Criterion) {
1990 let seed = [0u8; 32];
1991 let now = Duration::from_secs(genesis_block(Network::Testnet).header.time as u64);
1992 let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_micros()));
1994 let mut handles = Vec::new();
1995 let mut stops = Vec::new();
1997 let keys_manager_clone = Arc::clone(&keys_manager);
1998 let (stop_sender, stop_receiver) = mpsc::channel();
1999 let handle = thread::spawn(move || {
2001 keys_manager_clone.get_secure_random_bytes();
2002 match stop_receiver.try_recv() {
2003 Ok(_) | Err(TryRecvError::Disconnected) => {
2004 println!("Terminating.");
2007 Err(TryRecvError::Empty) => {}
2011 handles.push(handle);
2012 stops.push(stop_sender);
2015 bench.bench_function("get_secure_random_bytes", |b| b.iter(||
2016 keys_manager.get_secure_random_bytes()));
2019 let _ = stop.send(());
2021 for handle in handles {
2022 handle.join().unwrap();