1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Provides keys to LDK and defines some useful objects describing spendable on-chain outputs.
12 //! The provided output descriptors follow a custom LDK data format and are currently not fully
13 //! compatible with Bitcoin Core output descriptors.
15 use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, EcdsaSighashType};
16 use bitcoin::blockdata::script::{Script, Builder};
17 use bitcoin::blockdata::opcodes;
18 use bitcoin::network::constants::Network;
19 use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
20 use bitcoin::util::sighash;
22 use bitcoin::bech32::u5;
23 use bitcoin::hashes::{Hash, HashEngine};
24 use bitcoin::hashes::sha256::HashEngine as Sha256State;
25 use bitcoin::hashes::sha256::Hash as Sha256;
26 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
27 use bitcoin::hash_types::WPubkeyHash;
29 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
30 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Signing};
31 use bitcoin::secp256k1::ecdh::SharedSecret;
32 use bitcoin::secp256k1::ecdsa::RecoverableSignature;
33 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
35 use crate::util::transaction_utils;
36 use crate::util::crypto::{hkdf_extract_expand_twice, sign};
37 use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
39 use crate::util::events::HTLCDescriptor;
40 use crate::chain::transaction::OutPoint;
41 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
42 use crate::ln::{chan_utils, PaymentPreimage};
43 use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
44 use crate::ln::msgs::UnsignedChannelAnnouncement;
45 use crate::ln::script::ShutdownScript;
47 use crate::prelude::*;
48 use core::convert::TryInto;
49 use core::sync::atomic::{AtomicUsize, Ordering};
50 use crate::io::{self, Error};
51 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
52 use crate::util::invoice::construct_invoice_preimage;
54 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
55 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
57 /// (C-not exported) as we just use `[u8; 32]` directly
58 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
59 pub struct KeyMaterial(pub [u8; 32]);
61 /// Information about a spendable output to a P2WSH script.
63 /// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
64 #[derive(Clone, Debug, PartialEq, Eq)]
65 pub struct DelayedPaymentOutputDescriptor {
66 /// The outpoint which is spendable.
67 pub outpoint: OutPoint,
68 /// Per commitment point to derive the delayed payment key by key holder.
69 pub per_commitment_point: PublicKey,
70 /// The `nSequence` value which must be set in the spending input to satisfy the `OP_CSV` in
71 /// the witness_script.
72 pub to_self_delay: u16,
73 /// The output which is referenced by the given outpoint.
75 /// The revocation point specific to the commitment transaction which was broadcast. Used to
76 /// derive the witnessScript for this output.
77 pub revocation_pubkey: PublicKey,
78 /// Arbitrary identification information returned by a call to [`BaseSign::channel_keys_id`].
79 /// This may be useful in re-deriving keys used in the channel to spend the output.
80 pub channel_keys_id: [u8; 32],
81 /// The value of the channel which this output originated from, possibly indirectly.
82 pub channel_value_satoshis: u64,
84 impl DelayedPaymentOutputDescriptor {
85 /// The maximum length a well-formed witness spending one of these should have.
86 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
87 // redeemscript push length.
88 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
91 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
92 (0, outpoint, required),
93 (2, per_commitment_point, required),
94 (4, to_self_delay, required),
95 (6, output, required),
96 (8, revocation_pubkey, required),
97 (10, channel_keys_id, required),
98 (12, channel_value_satoshis, required),
101 /// Information about a spendable output to our "payment key".
103 /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
104 #[derive(Clone, Debug, PartialEq, Eq)]
105 pub struct StaticPaymentOutputDescriptor {
106 /// The outpoint which is spendable.
107 pub outpoint: OutPoint,
108 /// The output which is referenced by the given outpoint.
110 /// Arbitrary identification information returned by a call to [`BaseSign::channel_keys_id`].
111 /// This may be useful in re-deriving keys used in the channel to spend the output.
112 pub channel_keys_id: [u8; 32],
113 /// The value of the channel which this transactions spends.
114 pub channel_value_satoshis: u64,
116 impl StaticPaymentOutputDescriptor {
117 /// The maximum length a well-formed witness spending one of these should have.
118 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
119 // redeemscript push length.
120 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
122 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
123 (0, outpoint, required),
124 (2, output, required),
125 (4, channel_keys_id, required),
126 (6, channel_value_satoshis, required),
129 /// Describes the necessary information to spend a spendable output.
131 /// When on-chain outputs are created by LDK (which our counterparty is not able to claim at any
132 /// point in the future) a [`SpendableOutputs`] event is generated which you must track and be able
133 /// to spend on-chain. The information needed to do this is provided in this enum, including the
134 /// outpoint describing which `txid` and output `index` is available, the full output which exists
135 /// at that `txid`/`index`, and any keys or other information required to sign.
137 /// [`SpendableOutputs`]: crate::util::events::Event::SpendableOutputs
138 #[derive(Clone, Debug, PartialEq, Eq)]
139 pub enum SpendableOutputDescriptor {
140 /// An output to a script which was provided via [`KeysInterface`] directly, either from
141 /// [`get_destination_script`] or [`get_shutdown_scriptpubkey`], thus you should already
142 /// know how to spend it. No secret keys are provided as LDK was never given any key.
143 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
144 /// on-chain using the payment preimage or after it has timed out.
146 /// [`get_shutdown_scriptpubkey`]: KeysInterface::get_shutdown_scriptpubkey
147 /// [`get_destination_script`]: KeysInterface::get_shutdown_scriptpubkey
149 /// The outpoint which is spendable.
151 /// The output which is referenced by the given outpoint.
154 /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
157 /// The witness in the spending input should be:
159 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
162 /// Note that the `nSequence` field in the spending input must be set to
163 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
164 /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
165 /// the outpoint confirms, see [BIP
166 /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
167 /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
170 /// These are generally the result of a "revocable" output to us, spendable only by us unless
171 /// it is an output from an old state which we broadcast (which should never happen).
173 /// To derive the delayed payment key which is used to sign this input, you must pass the
174 /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the
175 /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`BaseSign::pubkeys`]) and the provided
176 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The public key can be
177 /// generated without the secret key using [`chan_utils::derive_public_key`] and only the
178 /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`BaseSign::pubkeys`].
180 /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
181 /// used in the witness script generation), you must pass the counterparty
182 /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to
183 /// [`BaseSign::provide_channel_parameters`]) and the provided
184 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to
185 /// [`chan_utils::derive_public_revocation_key`].
187 /// The witness script which is hashed and included in the output `script_pubkey` may be
188 /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
189 /// as explained above), our delayed payment pubkey (derived as explained above), and the
190 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to
191 /// [`chan_utils::get_revokeable_redeemscript`].
192 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
193 /// An output to a P2WPKH, spendable exclusively by our payment key (i.e., the private key
194 /// which corresponds to the `payment_point` in [`BaseSign::pubkeys`]). The witness
195 /// in the spending input is, thus, simply:
197 /// <BIP 143 signature> <payment key>
200 /// These are generally the result of our counterparty having broadcast the current state,
201 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
202 StaticPaymentOutput(StaticPaymentOutputDescriptor),
205 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
206 (0, StaticOutput) => {
207 (0, outpoint, required),
208 (2, output, required),
211 (1, DelayedPaymentOutput),
212 (2, StaticPaymentOutput),
215 /// A trait to sign Lightning channel transactions as described in
216 /// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
218 /// Signing services could be implemented on a hardware wallet and should implement signing
219 /// policies in order to be secure. Please refer to the [VLS Policy
220 /// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md)
221 /// for an example of such policies.
223 /// Gets the per-commitment point for a specific commitment number
225 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
226 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
227 /// Gets the commitment secret for a specific commitment number as part of the revocation process
229 /// An external signer implementation should error here if the commitment was already signed
230 /// and should refuse to sign it in the future.
232 /// May be called more than once for the same index.
234 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
235 // TODO: return a Result so we can signal a validation error
236 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
237 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
239 /// This is required in order for the signer to make sure that releasing a commitment
240 /// secret won't leave us without a broadcastable holder transaction.
241 /// Policy checks should be implemented in this function, including checking the amount
242 /// sent to us and checking the HTLCs.
244 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
245 /// A validating signer should ensure that an HTLC output is removed only when the matching
246 /// preimage is provided, or when the value to holder is restored.
248 /// Note that all the relevant preimages will be provided, but there may also be additional
249 /// irrelevant or duplicate preimages.
250 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
251 preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
252 /// Returns the holder's channel public keys and basepoints.
253 fn pubkeys(&self) -> &ChannelPublicKeys;
254 /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
255 /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
256 /// [`BaseSign`] object uniquely and lookup or re-derive its keys.
257 fn channel_keys_id(&self) -> [u8; 32];
258 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
260 /// Note that if signing fails or is rejected, the channel will be force-closed.
262 /// Policy checks should be implemented in this function, including checking the amount
263 /// sent to us and checking the HTLCs.
265 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
266 /// A validating signer should ensure that an HTLC output is removed only when the matching
267 /// preimage is provided, or when the value to holder is restored.
269 /// Note that all the relevant preimages will be provided, but there may also be additional
270 /// irrelevant or duplicate preimages.
272 // TODO: Document the things someone using this interface should enforce before signing.
273 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
274 preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
275 ) -> Result<(Signature, Vec<Signature>), ()>;
276 /// Validate the counterparty's revocation.
278 /// This is required in order for the signer to make sure that the state has moved
279 /// forward and it is safe to sign the next counterparty commitment.
280 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
281 /// Creates a signature for a holder's commitment transaction and its claiming HTLC transactions.
283 /// This will be called
284 /// - with a non-revoked `commitment_tx`.
285 /// - with the latest `commitment_tx` when we initiate a force-close.
286 /// - with the previous `commitment_tx`, just to get claiming HTLC
287 /// signatures, if we are reacting to a [`ChannelMonitor`]
288 /// [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas)
289 /// that decided to broadcast before it had been updated to the latest `commitment_tx`.
291 /// This may be called multiple times for the same transaction.
293 /// An external signer implementation should check that the commitment has not been revoked.
295 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
296 // TODO: Document the things someone using this interface should enforce before signing.
297 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction,
298 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
299 /// Same as [`sign_holder_commitment_and_htlcs`], but exists only for tests to get access to
300 /// holder commitment transactions which will be broadcasted later, after the channel has moved
301 /// on to a newer state. Thus, needs its own method as [`sign_holder_commitment_and_htlcs`] may
302 /// enforce that we only ever get called once.
303 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
304 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction,
305 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
306 /// Create a signature for the given input in a transaction spending an HTLC transaction output
307 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
309 /// A justice transaction may claim multiple outputs at the same time if timelocks are
310 /// similar, but only a signature for the input at index `input` should be signed for here.
311 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
312 /// to an upcoming timelock expiration.
314 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
316 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
317 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
318 /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do
320 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64,
321 per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>
322 ) -> Result<Signature, ()>;
323 /// Create a signature for the given input in a transaction spending a commitment transaction
324 /// HTLC output when our counterparty broadcasts an old state.
326 /// A justice transaction may claim multiple outputs at the same time if timelocks are
327 /// similar, but only a signature for the input at index `input` should be signed for here.
328 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
329 /// to an upcoming timelock expiration.
331 /// `amount` is the value of the output spent by this input, committed to in the BIP 143
334 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
335 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
336 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
339 /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script
340 /// (which is committed to in the BIP 143 signatures).
341 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64,
342 per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment,
343 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
345 /// Computes the signature for a commitment transaction's HTLC output used as an input within
346 /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned
347 /// must be be computed using [`EcdsaSighashType::All`]. Note that this should only be used to
348 /// sign HTLC transactions from channels supporting anchor outputs after all additional
349 /// inputs/outputs have been added to the transaction.
351 /// [`EcdsaSighashType::All`]: bitcoin::blockdata::transaction::EcdsaSighashType::All
352 fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize,
353 htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1<secp256k1::All>
354 ) -> Result<Signature, ()>;
355 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
356 /// transaction, either offered or received.
358 /// Such a transaction may claim multiples offered outputs at same time if we know the
359 /// preimage for each when we create it, but only the input at index `input` should be
360 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
361 /// needed with regards to an upcoming timelock expiration.
363 /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
366 /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
368 /// `per_commitment_point` is the dynamic point corresponding to the channel state
369 /// detected onchain. It has been generated by our counterparty and is used to derive
370 /// channel state keys, which are then included in the witness script and committed to in the
371 /// BIP 143 signature.
372 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64,
373 per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment,
374 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
375 /// Create a signature for a (proposed) closing transaction.
377 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
378 /// chosen to forgo their output as dust.
379 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
380 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
381 /// Computes the signature for a commitment transaction's anchor output used as an
382 /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
383 fn sign_holder_anchor_input(
384 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
385 ) -> Result<Signature, ()>;
386 /// Signs a channel announcement message with our funding key and our node secret key (aka
387 /// node_id or network_key), proving it comes from one of the channel participants.
389 /// The first returned signature should be from our node secret key, the second from our
392 /// Note that if this fails or is rejected, the channel will not be publicly announced and
393 /// our counterparty may (though likely will not) close the channel on us for violating the
395 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>)
396 -> Result<(Signature, Signature), ()>;
397 /// Set the counterparty static channel data, including basepoints,
398 /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint. Since these
399 /// are static channel data, they MUST NOT be allowed to change to different values once set,
400 /// as LDK may call this method more than once.
402 /// channel_parameters.is_populated() MUST be true.
403 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
406 /// A writeable signer.
408 /// There will always be two instances of a signer per channel, one occupied by the
409 /// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
411 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
412 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
413 pub trait Sign: BaseSign + Writeable + Clone {}
415 /// Specifies the recipient of an invoice.
417 /// This indicates to [`KeysInterface::sign_invoice`] what node secret key should be used to sign
420 /// The invoice should be signed with the local node secret key.
422 /// The invoice should be signed with the phantom node secret key. This secret key must be the
423 /// same for all nodes participating in the [phantom node payment].
425 /// [phantom node payment]: PhantomKeysManager
429 /// A trait to describe an object which can get user secrets and key material.
430 pub trait KeysInterface {
431 /// A type which implements [`Sign`] which will be returned by [`Self::derive_channel_signer`].
433 /// Get node secret key based on the provided [`Recipient`].
435 /// The `node_id`/`network_key` is the public key that corresponds to this secret key.
437 /// This method must return the same value each time it is called with a given [`Recipient`]
440 /// Errors if the [`Recipient`] variant is not supported by the implementation.
441 fn get_node_secret(&self, recipient: Recipient) -> Result<SecretKey, ()>;
442 /// Get node id based on the provided [`Recipient`]. This public key corresponds to the secret in
443 /// [`get_node_secret`].
445 /// This method must return the same value each time it is called with a given [`Recipient`]
448 /// Errors if the [`Recipient`] variant is not supported by the implementation.
450 /// [`get_node_secret`]: Self::get_node_secret
451 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
452 let secp_ctx = Secp256k1::signing_only();
453 Ok(PublicKey::from_secret_key(&secp_ctx, &self.get_node_secret(recipient)?))
455 /// Gets the ECDH shared secret of our [`node secret`] and `other_key`, multiplying by `tweak` if
456 /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
457 /// secret, though this is less efficient.
459 /// Errors if the [`Recipient`] variant is not supported by the implementation.
461 /// [`node secret`]: Self::get_node_secret
462 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
463 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
465 /// This method should return a different value each time it is called, to avoid linking
466 /// on-chain funds across channels as controlled to the same user.
467 fn get_destination_script(&self) -> Script;
468 /// Get a script pubkey which we will send funds to when closing a channel.
470 /// This method should return a different value each time it is called, to avoid linking
471 /// on-chain funds across channels as controlled to the same user.
472 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
473 /// Get a new set of [`Sign`] for per-channel secrets. These MUST be unique even if you
474 /// restarted with some stale data!
476 /// This method must return a different value each time it is called.
477 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
478 /// Derives the private key material backing a `Signer`.
480 /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
481 /// [`KeysInterface::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
482 /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
483 /// [`BaseSign::channel_keys_id`].
484 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer;
485 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
486 /// onion packets and for temporary channel IDs. There is no requirement that these be
487 /// persisted anywhere, though they must be unique across restarts.
489 /// This method must return a different value each time it is called.
490 fn get_secure_random_bytes(&self) -> [u8; 32];
491 /// Reads a [`Signer`] for this [`KeysInterface`] from the given input stream.
492 /// This is only called during deserialization of other objects which contain
493 /// [`Sign`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
494 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
495 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
496 /// you've read all of the provided bytes to ensure no corruption occurred.
498 /// This method is slowly being phased out -- it will only be called when reading objects
499 /// written by LDK versions prior to 0.0.113.
501 /// [`Signer`]: Self::Signer
502 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
503 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
504 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
506 /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
507 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
508 /// blindly signing the hash.
509 /// The `hrp` is ASCII bytes, while the invoice data is base32-encoded.
511 /// The secret key used to sign the invoice is dependent on the [`Recipient`].
513 /// Errors if the [`Recipient`] variant is not supported by the implementation.
514 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], receipient: Recipient) -> Result<RecoverableSignature, ()>;
515 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
517 /// If the implementor of this trait supports [phantom node payments], then every node that is
518 /// intended to be included in the phantom invoice route hints must return the same value from
520 // This is because LDK avoids storing inbound payment data by encrypting payment data in the
521 // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
522 // nodes, they must share the key that encrypts this payment data.
524 /// This method must return the same value each time it is called.
526 /// [phantom node payments]: PhantomKeysManager
527 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
531 /// A simple implementation of [`Sign`] that just keeps the private keys in memory.
533 /// This implementation performs no policy checks and is insufficient by itself as
534 /// a secure external signer.
535 pub struct InMemorySigner {
536 /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
537 /// holder's anchor output in a commitment transaction, if one is present.
538 pub funding_key: SecretKey,
539 /// Holder secret key for blinded revocation pubkey.
540 pub revocation_base_key: SecretKey,
541 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
542 pub payment_key: SecretKey,
543 /// Holder secret key used in an HTLC transaction.
544 pub delayed_payment_base_key: SecretKey,
545 /// Holder HTLC secret key used in commitment transaction HTLC outputs.
546 pub htlc_base_key: SecretKey,
548 pub commitment_seed: [u8; 32],
549 /// Holder public keys and basepoints.
550 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
551 /// Private key of our node secret, used for signing channel announcements.
552 node_secret: SecretKey,
553 /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
554 channel_parameters: Option<ChannelTransactionParameters>,
555 /// The total value of this channel.
556 channel_value_satoshis: u64,
557 /// Key derivation parameters.
558 channel_keys_id: [u8; 32],
561 impl InMemorySigner {
562 /// Creates a new [`InMemorySigner`].
563 pub fn new<C: Signing>(
564 secp_ctx: &Secp256k1<C>,
565 node_secret: SecretKey,
566 funding_key: SecretKey,
567 revocation_base_key: SecretKey,
568 payment_key: SecretKey,
569 delayed_payment_base_key: SecretKey,
570 htlc_base_key: SecretKey,
571 commitment_seed: [u8; 32],
572 channel_value_satoshis: u64,
573 channel_keys_id: [u8; 32],
574 ) -> InMemorySigner {
575 let holder_channel_pubkeys =
576 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
577 &payment_key, &delayed_payment_base_key,
583 delayed_payment_base_key,
587 channel_value_satoshis,
588 holder_channel_pubkeys,
589 channel_parameters: None,
594 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
595 funding_key: &SecretKey,
596 revocation_base_key: &SecretKey,
597 payment_key: &SecretKey,
598 delayed_payment_base_key: &SecretKey,
599 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
600 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
602 funding_pubkey: from_secret(&funding_key),
603 revocation_basepoint: from_secret(&revocation_base_key),
604 payment_point: from_secret(&payment_key),
605 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
606 htlc_basepoint: from_secret(&htlc_base_key),
610 /// Returns the counterparty's pubkeys.
612 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
613 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
614 /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
615 /// transactions, i.e., the amount of time that we have to wait to recover our funds if we
616 /// broadcast a transaction.
618 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
619 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
620 /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
621 /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
622 /// if they broadcast a transaction.
624 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
625 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
626 /// Returns whether the holder is the initiator.
628 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
629 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
632 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
633 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
634 /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
635 /// building transactions.
637 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
638 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
639 self.channel_parameters.as_ref().unwrap()
641 /// Returns whether anchors should be used.
643 /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
644 pub fn opt_anchors(&self) -> bool {
645 self.get_channel_parameters().opt_anchors.is_some()
647 /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
648 /// by `descriptor`, returning the witness stack for the input.
650 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
651 /// is not spending the outpoint described by [`descriptor.outpoint`],
652 /// or if an output descriptor `script_pubkey` does not match the one we can spend.
654 /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint
655 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
656 // TODO: We really should be taking the SigHashCache as a parameter here instead of
657 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
658 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
659 // bindings updates to support SigHashCache objects).
660 if spend_tx.input.len() <= input_idx { return Err(()); }
661 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
662 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
664 let remotepubkey = self.pubkeys().payment_point;
665 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Testnet).script_pubkey();
666 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
667 let remotesig = sign(secp_ctx, &sighash, &self.payment_key);
668 let payment_script = bitcoin::Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Bitcoin).unwrap().script_pubkey();
670 if payment_script != descriptor.output.script_pubkey { return Err(()); }
672 let mut witness = Vec::with_capacity(2);
673 witness.push(remotesig.serialize_der().to_vec());
674 witness[0].push(EcdsaSighashType::All as u8);
675 witness.push(remotepubkey.serialize().to_vec());
679 /// Sign the single input of `spend_tx` at index `input_idx` which spends the output
680 /// described by `descriptor`, returning the witness stack for the input.
682 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
683 /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
684 /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
685 /// `script_pubkey` does not match the one we can spend.
687 /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
688 /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
689 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
690 // TODO: We really should be taking the SigHashCache as a parameter here instead of
691 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
692 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
693 // bindings updates to support SigHashCache objects).
694 if spend_tx.input.len() <= input_idx { return Err(()); }
695 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
696 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
697 if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
699 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
700 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
701 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
702 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
703 let local_delayedsig = sign(secp_ctx, &sighash, &delayed_payment_key);
704 let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
706 if descriptor.output.script_pubkey != payment_script { return Err(()); }
708 let mut witness = Vec::with_capacity(3);
709 witness.push(local_delayedsig.serialize_der().to_vec());
710 witness[0].push(EcdsaSighashType::All as u8);
711 witness.push(vec!()); //MINIMALIF
712 witness.push(witness_script.clone().into_bytes());
717 impl BaseSign for InMemorySigner {
718 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
719 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
720 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
723 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
724 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
727 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
731 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
733 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
735 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
736 let trusted_tx = commitment_tx.trust();
737 let keys = trusted_tx.keys();
739 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
740 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
742 let built_tx = trusted_tx.built_transaction();
743 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
744 let commitment_txid = built_tx.txid;
746 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
747 for htlc in commitment_tx.htlcs() {
748 let channel_parameters = self.get_channel_parameters();
749 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), channel_parameters.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
750 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
751 let htlc_sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
752 let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
753 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
754 htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
757 Ok((commitment_sig, htlc_sigs))
760 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
764 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
765 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
766 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
767 let trusted_tx = commitment_tx.trust();
768 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
769 let channel_parameters = self.get_channel_parameters();
770 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
774 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
775 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
776 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
777 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
778 let trusted_tx = commitment_tx.trust();
779 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
780 let channel_parameters = self.get_channel_parameters();
781 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
785 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
786 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
787 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
788 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
789 let witness_script = {
790 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint);
791 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
793 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
794 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
795 return Ok(sign(secp_ctx, &sighash, &revocation_key))
798 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, ()> {
799 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
800 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
801 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
802 let witness_script = {
803 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
804 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
805 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
807 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
808 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
809 return Ok(sign(secp_ctx, &sighash, &revocation_key))
813 fn sign_holder_htlc_transaction(
814 &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
815 secp_ctx: &Secp256k1<secp256k1::All>
816 ) -> Result<Signature, ()> {
817 let per_commitment_point = self.get_per_commitment_point(
818 htlc_descriptor.per_commitment_number, &secp_ctx
820 let witness_script = htlc_descriptor.witness_script(&per_commitment_point, secp_ctx);
821 let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
822 input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
824 let our_htlc_private_key = chan_utils::derive_private_key(
825 &secp_ctx, &per_commitment_point, &self.htlc_base_key
827 Ok(sign(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key))
830 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, ()> {
831 let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
832 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
833 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
834 let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
835 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
836 let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
837 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
838 Ok(sign(secp_ctx, &sighash, &htlc_key))
841 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
842 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
843 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
844 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
847 fn sign_holder_anchor_input(
848 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
849 ) -> Result<Signature, ()> {
850 let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
851 let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
852 input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
854 Ok(sign(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key))
857 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>)
858 -> Result<(Signature, Signature), ()> {
859 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
860 Ok((sign(secp_ctx, &msghash, &self.node_secret), sign(secp_ctx, &msghash, &self.funding_key)))
863 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
864 assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
865 if self.channel_parameters.is_some() {
866 // The channel parameters were already set and they match, return early.
869 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
870 self.channel_parameters = Some(channel_parameters.clone());
874 const SERIALIZATION_VERSION: u8 = 1;
876 const MIN_SERIALIZATION_VERSION: u8 = 1;
878 impl Sign for InMemorySigner {}
880 impl Writeable for InMemorySigner {
881 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
882 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
884 self.funding_key.write(writer)?;
885 self.revocation_base_key.write(writer)?;
886 self.payment_key.write(writer)?;
887 self.delayed_payment_base_key.write(writer)?;
888 self.htlc_base_key.write(writer)?;
889 self.commitment_seed.write(writer)?;
890 self.channel_parameters.write(writer)?;
891 self.channel_value_satoshis.write(writer)?;
892 self.channel_keys_id.write(writer)?;
894 write_tlv_fields!(writer, {});
900 impl ReadableArgs<SecretKey> for InMemorySigner {
901 fn read<R: io::Read>(reader: &mut R, node_secret: SecretKey) -> Result<Self, DecodeError> {
902 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
904 let funding_key = Readable::read(reader)?;
905 let revocation_base_key = Readable::read(reader)?;
906 let payment_key = Readable::read(reader)?;
907 let delayed_payment_base_key = Readable::read(reader)?;
908 let htlc_base_key = Readable::read(reader)?;
909 let commitment_seed = Readable::read(reader)?;
910 let counterparty_channel_data = Readable::read(reader)?;
911 let channel_value_satoshis = Readable::read(reader)?;
912 let secp_ctx = Secp256k1::signing_only();
913 let holder_channel_pubkeys =
914 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
915 &payment_key, &delayed_payment_base_key, &htlc_base_key);
916 let keys_id = Readable::read(reader)?;
918 read_tlv_fields!(reader, {});
924 delayed_payment_base_key,
928 channel_value_satoshis,
929 holder_channel_pubkeys,
930 channel_parameters: counterparty_channel_data,
931 channel_keys_id: keys_id,
936 /// Simple [`KeysInterface`] implementation that takes a 32-byte seed for use as a BIP 32 extended
937 /// key and derives keys from that.
939 /// Your `node_id` is seed/0'.
940 /// Unilateral closes may use seed/1'.
941 /// Cooperative closes may use seed/2'.
942 /// The two close keys may be needed to claim on-chain funds!
944 /// This struct cannot be used for nodes that wish to support receiving phantom payments;
945 /// [`PhantomKeysManager`] must be used instead.
947 /// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
948 /// previously issued invoices and attempts to pay previous invoices will fail.
949 pub struct KeysManager {
950 secp_ctx: Secp256k1<secp256k1::All>,
951 node_secret: SecretKey,
953 inbound_payment_key: KeyMaterial,
954 destination_script: Script,
955 shutdown_pubkey: PublicKey,
956 channel_master_key: ExtendedPrivKey,
957 channel_child_index: AtomicUsize,
959 rand_bytes_master_key: ExtendedPrivKey,
960 rand_bytes_child_index: AtomicUsize,
961 rand_bytes_unique_start: Sha256State,
964 starting_time_secs: u64,
965 starting_time_nanos: u32,
969 /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
970 /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
971 /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
972 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
973 /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
974 /// is to simply use the current time (with very high precision).
976 /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
977 /// obviously, `starting_time` should be unique every time you reload the library - it is only
978 /// used to generate new ephemeral key data (which will be stored by the individual channel if
981 /// Note that the seed is required to recover certain on-chain funds independent of
982 /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
983 /// for any channel, and some on-chain during-closing funds.
985 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
986 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
987 let secp_ctx = Secp256k1::new();
988 // Note that when we aren't serializing the key, network doesn't matter
989 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
991 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key;
992 let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret);
993 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
994 Ok(destination_key) => {
995 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
996 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
997 .push_slice(&wpubkey_hash.into_inner())
1000 Err(_) => panic!("Your RNG is busted"),
1002 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
1003 Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key,
1004 Err(_) => panic!("Your RNG is busted"),
1006 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
1007 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
1008 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key;
1009 let mut inbound_pmt_key_bytes = [0; 32];
1010 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
1012 let mut rand_bytes_unique_start = Sha256::engine();
1013 rand_bytes_unique_start.input(&starting_time_secs.to_be_bytes());
1014 rand_bytes_unique_start.input(&starting_time_nanos.to_be_bytes());
1015 rand_bytes_unique_start.input(seed);
1017 let mut res = KeysManager {
1021 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
1027 channel_child_index: AtomicUsize::new(0),
1029 rand_bytes_master_key,
1030 rand_bytes_child_index: AtomicUsize::new(0),
1031 rand_bytes_unique_start,
1035 starting_time_nanos,
1037 let secp_seed = res.get_secure_random_bytes();
1038 res.secp_ctx.seeded_randomize(&secp_seed);
1041 Err(_) => panic!("Your rng is busted"),
1044 /// Derive an old [`Sign`] containing per-channel secrets based on a key derivation parameters.
1045 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1046 let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
1047 let mut unique_start = Sha256::engine();
1048 unique_start.input(params);
1049 unique_start.input(&self.seed);
1051 // We only seriously intend to rely on the channel_master_key for true secure
1052 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
1053 // starting_time provided in the constructor) to be unique.
1054 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx,
1055 ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted")
1056 ).expect("Your RNG is busted");
1057 unique_start.input(&child_privkey.private_key[..]);
1059 let seed = Sha256::from_engine(unique_start).into_inner();
1061 let commitment_seed = {
1062 let mut sha = Sha256::engine();
1064 sha.input(&b"commitment seed"[..]);
1065 Sha256::from_engine(sha).into_inner()
1067 macro_rules! key_step {
1068 ($info: expr, $prev_key: expr) => {{
1069 let mut sha = Sha256::engine();
1071 sha.input(&$prev_key[..]);
1072 sha.input(&$info[..]);
1073 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
1076 let funding_key = key_step!(b"funding key", commitment_seed);
1077 let revocation_base_key = key_step!(b"revocation base key", funding_key);
1078 let payment_key = key_step!(b"payment key", revocation_base_key);
1079 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
1080 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
1082 InMemorySigner::new(
1086 revocation_base_key,
1088 delayed_payment_base_key,
1091 channel_value_satoshis,
1096 /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
1097 /// output to the given change destination (if sufficient change value remains). The
1098 /// transaction will have a feerate, at least, of the given value.
1100 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
1101 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
1102 /// does not match the one we can spend.
1104 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
1106 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1107 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1108 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1109 let mut input = Vec::new();
1110 let mut input_value = 0;
1111 let mut witness_weight = 0;
1112 let mut output_set = HashSet::with_capacity(descriptors.len());
1113 for outp in descriptors {
1115 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1117 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
1118 script_sig: Script::new(),
1119 sequence: Sequence::ZERO,
1120 witness: Witness::new(),
1122 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
1123 input_value += descriptor.output.value;
1124 if !output_set.insert(descriptor.outpoint) { return Err(()); }
1126 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1128 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
1129 script_sig: Script::new(),
1130 sequence: Sequence(descriptor.to_self_delay as u32),
1131 witness: Witness::new(),
1133 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
1134 input_value += descriptor.output.value;
1135 if !output_set.insert(descriptor.outpoint) { return Err(()); }
1137 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
1139 previous_output: outpoint.into_bitcoin_outpoint(),
1140 script_sig: Script::new(),
1141 sequence: Sequence::ZERO,
1142 witness: Witness::new(),
1144 witness_weight += 1 + 73 + 34;
1145 input_value += output.value;
1146 if !output_set.insert(*outpoint) { return Err(()); }
1149 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
1151 let mut spend_tx = Transaction {
1153 lock_time: PackedLockTime(0),
1157 let expected_max_weight =
1158 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
1160 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
1161 let mut input_idx = 0;
1162 for outp in descriptors {
1164 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1165 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1167 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1168 descriptor.channel_keys_id));
1170 spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
1172 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1173 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1175 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1176 descriptor.channel_keys_id));
1178 spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
1180 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
1181 let derivation_idx = if output.script_pubkey == self.destination_script {
1187 // Note that when we aren't serializing the key, network doesn't matter
1188 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1190 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1192 Err(_) => panic!("Your RNG is busted"),
1195 Err(_) => panic!("Your rng is busted"),
1198 let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
1199 if derivation_idx == 2 {
1200 assert_eq!(pubkey.inner, self.shutdown_pubkey);
1202 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1203 let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey();
1205 if payment_script != output.script_pubkey { return Err(()); };
1207 let sighash = hash_to_message!(&sighash::SighashCache::new(&spend_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
1208 let sig = sign(secp_ctx, &sighash, &secret.private_key);
1209 let mut sig_ser = sig.serialize_der().to_vec();
1210 sig_ser.push(EcdsaSighashType::All as u8);
1211 spend_tx.input[input_idx].witness.push(sig_ser);
1212 spend_tx.input[input_idx].witness.push(pubkey.inner.serialize().to_vec());
1218 debug_assert!(expected_max_weight >= spend_tx.weight());
1219 // Note that witnesses with a signature vary somewhat in size, so allow
1220 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1221 debug_assert!(expected_max_weight <= spend_tx.weight() + descriptors.len() * 3);
1227 impl KeysInterface for KeysManager {
1228 type Signer = InMemorySigner;
1230 fn get_node_secret(&self, recipient: Recipient) -> Result<SecretKey, ()> {
1232 Recipient::Node => Ok(self.node_secret.clone()),
1233 Recipient::PhantomNode => Err(())
1237 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1239 Recipient::Node => Ok(self.node_id.clone()),
1240 Recipient::PhantomNode => Err(())
1244 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1245 let mut node_secret = self.get_node_secret(recipient)?;
1246 if let Some(tweak) = tweak {
1247 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1249 Ok(SharedSecret::new(other_key, &node_secret))
1252 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1253 self.inbound_payment_key.clone()
1256 fn get_destination_script(&self) -> Script {
1257 self.destination_script.clone()
1260 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1261 ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
1264 fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1265 let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1266 // `child_idx` is the only thing guaranteed to make each channel unique without a restart
1267 // (though `user_channel_id` should help, depending on user behavior). If it manages to
1268 // roll over, we may generate duplicate keys for two different channels, which could result
1269 // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
1270 // doesn't reach `u32::MAX`.
1271 assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
1272 let mut id = [0; 32];
1273 id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
1274 id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
1275 id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
1276 id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
1280 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1281 self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
1284 fn get_secure_random_bytes(&self) -> [u8; 32] {
1285 let mut sha = self.rand_bytes_unique_start.clone();
1287 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1288 let child_privkey = self.rand_bytes_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
1289 sha.input(&child_privkey.private_key[..]);
1291 sha.input(b"Unique Secure Random Bytes Salt");
1292 Sha256::from_engine(sha).into_inner()
1295 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1296 InMemorySigner::read(&mut io::Cursor::new(reader), self.node_secret.clone())
1299 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1300 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1301 let secret = match recipient {
1302 Recipient::Node => self.get_node_secret(Recipient::Node)?,
1303 Recipient::PhantomNode => return Err(()),
1305 Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), &secret))
1309 /// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
1312 /// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
1313 /// paid to one of multiple nodes. This works because we encode the invoice route hints such that
1314 /// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
1315 /// itself without ever needing to forward to this fake node.
1317 /// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
1318 /// provide some fault tolerance, because payers will automatically retry paying other provided
1319 /// nodes in the case that one node goes down.
1321 /// Note that multi-path payments are not supported in phantom invoices for security reasons.
1322 // In the hypothetical case that we did support MPP phantom payments, there would be no way for
1323 // nodes to know when the full payment has been received (and the preimage can be released) without
1324 // significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
1325 // to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
1326 // is released too early.
1328 /// Switching between this struct and [`KeysManager`] will invalidate any previously issued
1329 /// invoices and attempts to pay previous invoices will fail.
1330 pub struct PhantomKeysManager {
1332 inbound_payment_key: KeyMaterial,
1333 phantom_secret: SecretKey,
1334 phantom_node_id: PublicKey,
1337 impl KeysInterface for PhantomKeysManager {
1338 type Signer = InMemorySigner;
1340 fn get_node_secret(&self, recipient: Recipient) -> Result<SecretKey, ()> {
1342 Recipient::Node => self.inner.get_node_secret(Recipient::Node),
1343 Recipient::PhantomNode => Ok(self.phantom_secret.clone()),
1347 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1349 Recipient::Node => self.inner.get_node_id(Recipient::Node),
1350 Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
1354 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1355 let mut node_secret = self.get_node_secret(recipient)?;
1356 if let Some(tweak) = tweak {
1357 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1359 Ok(SharedSecret::new(other_key, &node_secret))
1362 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1363 self.inbound_payment_key.clone()
1366 fn get_destination_script(&self) -> Script {
1367 self.inner.get_destination_script()
1370 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1371 self.inner.get_shutdown_scriptpubkey()
1374 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1375 self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
1378 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1379 self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
1382 fn get_secure_random_bytes(&self) -> [u8; 32] {
1383 self.inner.get_secure_random_bytes()
1386 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1387 self.inner.read_chan_signer(reader)
1390 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1391 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1392 let secret = self.get_node_secret(recipient)?;
1393 Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), &secret))
1397 impl PhantomKeysManager {
1398 /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
1399 /// that is shared across all nodes that intend to participate in [phantom node payments]
1402 /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
1403 /// `starting_time_nanos`.
1405 /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
1406 /// same across restarts, or else inbound payments may fail.
1408 /// [phantom node payments]: PhantomKeysManager
1409 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self {
1410 let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos);
1411 let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed);
1412 let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
1413 let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
1416 inbound_payment_key: KeyMaterial(inbound_key),
1422 /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
1423 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1424 self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, secp_ctx)
1427 /// See [`KeysManager::derive_channel_keys`] for documentation on this method.
1428 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1429 self.inner.derive_channel_keys(channel_value_satoshis, params)
1433 // Ensure that BaseSign can have a vtable
1436 let _signer: Box<dyn BaseSign>;