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 //! keysinterface provides keys into rust-lightning and defines some useful enums which describe
11 //! spendable on-chain outputs which the user owns and is responsible for using just as any other
12 //! on-chain output which is theirs.
14 use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, SigHashType};
15 use bitcoin::blockdata::script::{Script, Builder};
16 use bitcoin::blockdata::opcodes;
17 use bitcoin::network::constants::Network;
18 use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
19 use bitcoin::util::bip143;
21 use bitcoin::hashes::{Hash, HashEngine};
22 use bitcoin::hashes::sha256::HashEngine as Sha256State;
23 use bitcoin::hashes::sha256::Hash as Sha256;
24 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
25 use bitcoin::hash_types::WPubkeyHash;
27 use bitcoin::secp256k1::key::{SecretKey, PublicKey};
28 use bitcoin::secp256k1::{Secp256k1, Signature, Signing};
29 use bitcoin::secp256k1;
31 use util::{byte_utils, transaction_utils};
32 use util::ser::{Writeable, Writer, Readable};
34 use chain::transaction::OutPoint;
36 use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
37 use ln::msgs::UnsignedChannelAnnouncement;
39 use std::collections::HashSet;
40 use std::sync::atomic::{AtomicUsize, Ordering};
42 use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
44 /// Information about a spendable output to a P2WSH script. See
45 /// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
46 #[derive(Clone, Debug, PartialEq)]
47 pub struct DelayedPaymentOutputDescriptor {
48 /// The outpoint which is spendable
49 pub outpoint: OutPoint,
50 /// Per commitment point to derive delayed_payment_key by key holder
51 pub per_commitment_point: PublicKey,
52 /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
53 /// the witness_script.
54 pub to_self_delay: u16,
55 /// The output which is referenced by the given outpoint
57 /// The revocation point specific to the commitment transaction which was broadcast. Used to
58 /// derive the witnessScript for this output.
59 pub revocation_pubkey: PublicKey,
60 /// Arbitrary identification information returned by a call to
61 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
62 /// the channel to spend the output.
63 pub channel_keys_id: [u8; 32],
64 /// The value of the channel which this output originated from, possibly indirectly.
65 pub channel_value_satoshis: u64,
67 impl DelayedPaymentOutputDescriptor {
68 /// The maximum length a well-formed witness spending one of these should have.
69 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
70 // redeemscript push length.
71 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
74 /// Information about a spendable output to our "payment key". See
75 /// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
76 #[derive(Clone, Debug, PartialEq)]
77 pub struct StaticPaymentOutputDescriptor {
78 /// The outpoint which is spendable
79 pub outpoint: OutPoint,
80 /// The output which is referenced by the given outpoint
82 /// Arbitrary identification information returned by a call to
83 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
84 /// the channel to spend the output.
85 pub channel_keys_id: [u8; 32],
86 /// The value of the channel which this transactions spends.
87 pub channel_value_satoshis: u64,
89 impl StaticPaymentOutputDescriptor {
90 /// The maximum length a well-formed witness spending one of these should have.
91 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
92 // redeemscript push length.
93 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
96 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
97 /// claim at any point in the future) an event is generated which you must track and be able to
98 /// spend on-chain. The information needed to do this is provided in this enum, including the
99 /// outpoint describing which txid and output index is available, the full output which exists at
100 /// that txid/index, and any keys or other information required to sign.
101 #[derive(Clone, Debug, PartialEq)]
102 pub enum SpendableOutputDescriptor {
103 /// An output to a script which was provided via KeysInterface directly, either from
104 /// `get_destination_script()` or `get_shutdown_pubkey()`, thus you should already know how to
105 /// spend it. No secret keys are provided as rust-lightning was never given any key.
106 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
107 /// on-chain using the payment preimage or after it has timed out.
109 /// The outpoint which is spendable
111 /// The output which is referenced by the given outpoint.
114 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
116 /// The witness in the spending input should be:
117 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
119 /// Note that the nSequence field in the spending input must be set to to_self_delay
120 /// (which means the transaction is not broadcastable until at least to_self_delay
121 /// blocks after the outpoint confirms).
123 /// These are generally the result of a "revocable" output to us, spendable only by us unless
124 /// it is an output from an old state which we broadcast (which should never happen).
126 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
127 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
128 /// Sign::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
129 /// chan_utils::derive_private_key. The public key can be generated without the secret key
130 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
133 /// To derive the revocation_pubkey provided here (which is used in the witness
134 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
135 /// call to Sign::ready_channel) and the provided per_commitment point
136 /// to chan_utils::derive_public_revocation_key.
138 /// The witness script which is hashed and included in the output script_pubkey may be
139 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
140 /// (derived as above), and the to_self_delay contained here to
141 /// chan_utils::get_revokeable_redeemscript.
142 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
143 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
144 /// corresponds to the public key in Sign::pubkeys().payment_point).
145 /// The witness in the spending input, is, thus, simply:
146 /// <BIP 143 signature> <payment key>
148 /// These are generally the result of our counterparty having broadcast the current state,
149 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
150 StaticPaymentOutput(StaticPaymentOutputDescriptor),
153 impl Writeable for SpendableOutputDescriptor {
154 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
156 &SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
158 outpoint.write(writer)?;
159 output.write(writer)?;
161 &SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) => {
163 descriptor.outpoint.write(writer)?;
164 descriptor.per_commitment_point.write(writer)?;
165 descriptor.to_self_delay.write(writer)?;
166 descriptor.output.write(writer)?;
167 descriptor.revocation_pubkey.write(writer)?;
168 descriptor.channel_keys_id.write(writer)?;
169 descriptor.channel_value_satoshis.write(writer)?;
171 &SpendableOutputDescriptor::StaticPaymentOutput(ref descriptor) => {
173 descriptor.outpoint.write(writer)?;
174 descriptor.output.write(writer)?;
175 descriptor.channel_keys_id.write(writer)?;
176 descriptor.channel_value_satoshis.write(writer)?;
183 impl Readable for SpendableOutputDescriptor {
184 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
185 match Readable::read(reader)? {
186 0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
187 outpoint: Readable::read(reader)?,
188 output: Readable::read(reader)?,
190 1u8 => Ok(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
191 outpoint: Readable::read(reader)?,
192 per_commitment_point: Readable::read(reader)?,
193 to_self_delay: Readable::read(reader)?,
194 output: Readable::read(reader)?,
195 revocation_pubkey: Readable::read(reader)?,
196 channel_keys_id: Readable::read(reader)?,
197 channel_value_satoshis: Readable::read(reader)?,
199 2u8 => Ok(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
200 outpoint: Readable::read(reader)?,
201 output: Readable::read(reader)?,
202 channel_keys_id: Readable::read(reader)?,
203 channel_value_satoshis: Readable::read(reader)?,
205 _ => Err(DecodeError::InvalidValue),
210 /// A trait to sign lightning channel transactions as described in BOLT 3.
212 /// Signing services could be implemented on a hardware wallet. In this case,
213 /// the current Sign would be a front-end on top of a communication
214 /// channel connected to your secure device and lightning key material wouldn't
215 /// reside on a hot server. Nevertheless, a this deployment would still need
216 /// to trust the ChannelManager to avoid loss of funds as this latest component
217 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
219 /// A more secure iteration would be to use hashlock (or payment points) to pair
220 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
221 /// at the price of more state and computation on the hardware wallet side. In the future,
222 /// we are looking forward to design such interface.
224 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
225 /// to act, as liveness and breach reply correctness are always going to be hard requirements
226 /// of LN security model, orthogonal of key management issues.
227 // TODO: We should remove Clone by instead requesting a new Sign copy when we create
228 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
229 pub trait BaseSign : Send {
230 /// Gets the per-commitment point for a specific commitment number
232 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
233 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
234 /// Gets the commitment secret for a specific commitment number as part of the revocation process
236 /// An external signer implementation should error here if the commitment was already signed
237 /// and should refuse to sign it in the future.
239 /// May be called more than once for the same index.
241 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
242 // TODO: return a Result so we can signal a validation error
243 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
244 /// Gets the holder's channel public keys and basepoints
245 fn pubkeys(&self) -> &ChannelPublicKeys;
246 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
247 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
248 /// Sign object uniquely and lookup or re-derive its keys.
249 fn channel_keys_id(&self) -> [u8; 32];
251 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
253 /// Note that if signing fails or is rejected, the channel will be force-closed.
255 // TODO: Document the things someone using this interface should enforce before signing.
256 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
258 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
259 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
260 /// latest commitment_tx when we initiate a force-close.
261 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
262 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
264 /// This may be called multiple times for the same transaction.
266 /// An external signer implementation should check that the commitment has not been revoked.
268 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
270 // TODO: Document the things someone using this interface should enforce before signing.
271 // TODO: Key derivation failure should panic rather than Err
272 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
274 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
275 /// transactions which will be broadcasted later, after the channel has moved on to a newer
276 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
278 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
279 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
281 /// Create a signature for the given input in a transaction spending an HTLC or commitment
282 /// transaction output when our counterparty broadcasts an old state.
284 /// A justice transaction may claim multiples outputs at the same time if timelocks are
285 /// similar, but only a signature for the input at index `input` should be signed for here.
286 /// It may be called multiples time for same output(s) if a fee-bump is needed with regards
287 /// to an upcoming timelock expiration.
289 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
291 /// per_commitment_key is revocation secret which was provided by our counterparty when they
292 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
293 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
296 /// htlc holds HTLC elements (hash, timelock) if the output being spent is a HTLC output, thus
297 /// changing the format of the witness script (which is committed to in the BIP 143
299 fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
301 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
302 /// transaction, either offered or received.
304 /// Such a transaction may claim multiples offered outputs at same time if we know the
305 /// preimage for each when we create it, but only the input at index `input` should be
306 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
307 /// needed with regards to an upcoming timelock expiration.
309 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
312 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
314 /// Per_commitment_point is the dynamic point corresponding to the channel state
315 /// detected onchain. It has been generated by our counterparty and is used to derive
316 /// channel state keys, which are then included in the witness script and committed to in the
317 /// BIP 143 signature.
318 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, ()>;
320 /// Create a signature for a (proposed) closing transaction.
322 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
323 /// chosen to forgo their output as dust.
324 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
326 /// Signs a channel announcement message with our funding key, proving it comes from one
327 /// of the channel participants.
329 /// Note that if this fails or is rejected, the channel will not be publicly announced and
330 /// our counterparty may (though likely will not) close the channel on us for violating the
332 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
334 /// Set the counterparty static channel data, including basepoints,
335 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
336 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
337 /// they MUST NOT be allowed to change to different values once set.
339 /// channel_parameters.is_populated() MUST be true.
341 /// We bind holder_selected_contest_delay late here for API convenience.
343 /// Will be called before any signatures are applied.
344 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
347 /// A cloneable signer.
349 /// Although we require signers to be cloneable, it may be useful for developers to be able to use
350 /// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
351 /// which implies Sized, into this derived trait.
352 pub trait Sign: BaseSign + Writeable + Clone {
355 /// A trait to describe an object which can get user secrets and key material.
356 pub trait KeysInterface: Send + Sync {
357 /// A type which implements Sign which will be returned by get_channel_signer.
360 /// Get node secret key (aka node_id or network_key).
362 /// This method must return the same value each time it is called.
363 fn get_node_secret(&self) -> SecretKey;
364 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
366 /// This method should return a different value each time it is called, to avoid linking
367 /// on-chain funds across channels as controlled to the same user.
368 fn get_destination_script(&self) -> Script;
369 /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
372 /// This method should return a different value each time it is called, to avoid linking
373 /// on-chain funds across channels as controlled to the same user.
374 fn get_shutdown_pubkey(&self) -> PublicKey;
375 /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
376 /// restarted with some stale data!
378 /// This method must return a different value each time it is called.
379 fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
380 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
381 /// onion packets and for temporary channel IDs. There is no requirement that these be
382 /// persisted anywhere, though they must be unique across restarts.
384 /// This method must return a different value each time it is called.
385 fn get_secure_random_bytes(&self) -> [u8; 32];
387 /// Reads a `Signer` for this `KeysInterface` from the given input stream.
388 /// This is only called during deserialization of other objects which contain
389 /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
390 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
391 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
392 /// you've read all of the provided bytes to ensure no corruption occurred.
393 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
397 /// A simple implementation of Sign that just keeps the private keys in memory.
399 /// This implementation performs no policy checks and is insufficient by itself as
400 /// a secure external signer.
401 pub struct InMemorySigner {
402 /// Private key of anchor tx
403 pub funding_key: SecretKey,
404 /// Holder secret key for blinded revocation pubkey
405 pub revocation_base_key: SecretKey,
406 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
407 pub payment_key: SecretKey,
408 /// Holder secret key used in HTLC tx
409 pub delayed_payment_base_key: SecretKey,
410 /// Holder htlc secret key used in commitment tx htlc outputs
411 pub htlc_base_key: SecretKey,
413 pub commitment_seed: [u8; 32],
414 /// Holder public keys and basepoints
415 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
416 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
417 channel_parameters: Option<ChannelTransactionParameters>,
418 /// The total value of this channel
419 channel_value_satoshis: u64,
420 /// Key derivation parameters
421 channel_keys_id: [u8; 32],
424 impl InMemorySigner {
425 /// Create a new InMemorySigner
426 pub fn new<C: Signing>(
427 secp_ctx: &Secp256k1<C>,
428 funding_key: SecretKey,
429 revocation_base_key: SecretKey,
430 payment_key: SecretKey,
431 delayed_payment_base_key: SecretKey,
432 htlc_base_key: SecretKey,
433 commitment_seed: [u8; 32],
434 channel_value_satoshis: u64,
435 channel_keys_id: [u8; 32]) -> InMemorySigner {
436 let holder_channel_pubkeys =
437 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
438 &payment_key, &delayed_payment_base_key,
444 delayed_payment_base_key,
447 channel_value_satoshis,
448 holder_channel_pubkeys,
449 channel_parameters: None,
454 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
455 funding_key: &SecretKey,
456 revocation_base_key: &SecretKey,
457 payment_key: &SecretKey,
458 delayed_payment_base_key: &SecretKey,
459 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
460 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
462 funding_pubkey: from_secret(&funding_key),
463 revocation_basepoint: from_secret(&revocation_base_key),
464 payment_point: from_secret(&payment_key),
465 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
466 htlc_basepoint: from_secret(&htlc_base_key),
470 /// Counterparty pubkeys.
471 /// Will panic if ready_channel wasn't called.
472 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
474 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
475 /// transactions, ie the amount of time that we have to wait to recover our funds if we
476 /// broadcast a transaction.
477 /// Will panic if ready_channel wasn't called.
478 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
480 /// The contest_delay value specified by us and applied on transactions broadcastable
481 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
482 /// if they broadcast a transaction.
483 /// Will panic if ready_channel wasn't called.
484 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
486 /// Whether the holder is the initiator
487 /// Will panic if ready_channel wasn't called.
488 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
491 /// Will panic if ready_channel wasn't called.
492 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
494 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
495 /// building transactions.
497 /// Will panic if ready_channel wasn't called.
498 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
499 self.channel_parameters.as_ref().unwrap()
502 /// Sign the single input of spend_tx at index `input_idx` which spends the output
503 /// described by descriptor, returning the witness stack for the input.
505 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
506 /// or is not spending the outpoint described by `descriptor.outpoint`.
507 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>>, ()> {
508 // TODO: We really should be taking the SigHashCache as a parameter here instead of
509 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
510 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
511 // bindings updates to support SigHashCache objects).
512 if spend_tx.input.len() <= input_idx { return Err(()); }
513 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
514 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
516 let remotepubkey = self.pubkeys().payment_point;
517 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
518 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
519 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
521 let mut witness = Vec::with_capacity(2);
522 witness.push(remotesig.serialize_der().to_vec());
523 witness[0].push(SigHashType::All as u8);
524 witness.push(remotepubkey.serialize().to_vec());
528 /// Sign the single input of spend_tx at index `input_idx` which spends the output
529 /// described by descriptor, returning the witness stack for the input.
531 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
532 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
533 /// sequence set to `descriptor.to_self_delay`.
534 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>>, ()> {
535 // TODO: We really should be taking the SigHashCache as a parameter here instead of
536 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
537 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
538 // bindings updates to support SigHashCache objects).
539 if spend_tx.input.len() <= input_idx { return Err(()); }
540 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
541 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
542 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
544 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
545 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
546 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
547 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
548 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
549 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
551 let mut witness = Vec::with_capacity(3);
552 witness.push(local_delayedsig.serialize_der().to_vec());
553 witness[0].push(SigHashType::All as u8);
554 witness.push(vec!()); //MINIMALIF
555 witness.push(witness_script.clone().into_bytes());
560 impl BaseSign for InMemorySigner {
561 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
562 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
563 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
566 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
567 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
570 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
571 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
573 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
574 let trusted_tx = commitment_tx.trust();
575 let keys = trusted_tx.keys();
577 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
578 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
580 let built_tx = trusted_tx.built_transaction();
581 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
582 let commitment_txid = built_tx.txid;
584 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
585 for htlc in commitment_tx.htlcs() {
586 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
587 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
588 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
589 let holder_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) {
591 Err(_) => return Err(()),
593 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
596 Ok((commitment_sig, htlc_sigs))
599 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
600 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
601 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
602 let trusted_tx = commitment_tx.trust();
603 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
604 let channel_parameters = self.get_channel_parameters();
605 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
609 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
610 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
611 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
612 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
613 let trusted_tx = commitment_tx.trust();
614 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
615 let channel_parameters = self.get_channel_parameters();
616 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
620 fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
621 let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
622 Ok(revocation_key) => revocation_key,
623 Err(_) => return Err(())
625 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
626 let revocation_pubkey = match chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
627 Ok(revocation_pubkey) => revocation_pubkey,
628 Err(_) => return Err(())
630 let witness_script = if let &Some(ref htlc) = htlc {
631 let counterparty_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
632 Ok(counterparty_htlcpubkey) => counterparty_htlcpubkey,
633 Err(_) => return Err(())
635 let holder_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
636 Ok(holder_htlcpubkey) => holder_htlcpubkey,
637 Err(_) => return Err(())
639 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
641 let counterparty_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint) {
642 Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey,
643 Err(_) => return Err(())
645 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
647 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
648 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
649 return Ok(secp_ctx.sign(&sighash, &revocation_key))
652 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, ()> {
653 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
654 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
655 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
656 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
657 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
658 } else { return Err(()) }
659 } else { return Err(()) }
660 } else { return Err(()) };
661 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
662 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
663 return Ok(secp_ctx.sign(&sighash, &htlc_key))
668 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
669 if closing_tx.input.len() != 1 { return Err(()); }
670 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
671 if closing_tx.output.len() > 2 { return Err(()); }
673 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
674 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
676 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
677 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
678 Ok(secp_ctx.sign(&sighash, &self.funding_key))
681 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
682 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
683 Ok(secp_ctx.sign(&msghash, &self.funding_key))
686 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
687 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
688 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
689 self.channel_parameters = Some(channel_parameters.clone());
693 impl Sign for InMemorySigner {}
695 impl Writeable for InMemorySigner {
696 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
697 self.funding_key.write(writer)?;
698 self.revocation_base_key.write(writer)?;
699 self.payment_key.write(writer)?;
700 self.delayed_payment_base_key.write(writer)?;
701 self.htlc_base_key.write(writer)?;
702 self.commitment_seed.write(writer)?;
703 self.channel_parameters.write(writer)?;
704 self.channel_value_satoshis.write(writer)?;
705 self.channel_keys_id.write(writer)?;
711 impl Readable for InMemorySigner {
712 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
713 let funding_key = Readable::read(reader)?;
714 let revocation_base_key = Readable::read(reader)?;
715 let payment_key = Readable::read(reader)?;
716 let delayed_payment_base_key = Readable::read(reader)?;
717 let htlc_base_key = Readable::read(reader)?;
718 let commitment_seed = Readable::read(reader)?;
719 let counterparty_channel_data = Readable::read(reader)?;
720 let channel_value_satoshis = Readable::read(reader)?;
721 let secp_ctx = Secp256k1::signing_only();
722 let holder_channel_pubkeys =
723 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
724 &payment_key, &delayed_payment_base_key,
726 let keys_id = Readable::read(reader)?;
732 delayed_payment_base_key,
735 channel_value_satoshis,
736 holder_channel_pubkeys,
737 channel_parameters: counterparty_channel_data,
738 channel_keys_id: keys_id,
743 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
744 /// and derives keys from that.
746 /// Your node_id is seed/0'
747 /// ChannelMonitor closes may use seed/1'
748 /// Cooperative closes may use seed/2'
749 /// The two close keys may be needed to claim on-chain funds!
750 pub struct KeysManager {
751 secp_ctx: Secp256k1<secp256k1::All>,
752 node_secret: SecretKey,
753 destination_script: Script,
754 shutdown_pubkey: PublicKey,
755 channel_master_key: ExtendedPrivKey,
756 channel_child_index: AtomicUsize,
758 rand_bytes_master_key: ExtendedPrivKey,
759 rand_bytes_child_index: AtomicUsize,
760 rand_bytes_unique_start: Sha256State,
763 starting_time_secs: u64,
764 starting_time_nanos: u32,
768 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
769 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
770 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
771 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
772 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
773 /// simply use the current time (with very high precision).
775 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
776 /// obviously, starting_time should be unique every time you reload the library - it is only
777 /// used to generate new ephemeral key data (which will be stored by the individual channel if
780 /// Note that the seed is required to recover certain on-chain funds independent of
781 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
782 /// channel, and some on-chain during-closing funds.
784 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
785 /// versions. Once the library is more fully supported, the docs will be updated to include a
786 /// detailed description of the guarantee.
787 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
788 let secp_ctx = Secp256k1::new();
789 // Note that when we aren't serializing the key, network doesn't matter
790 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
792 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
793 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
794 Ok(destination_key) => {
795 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
796 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
797 .push_slice(&wpubkey_hash.into_inner())
800 Err(_) => panic!("Your RNG is busted"),
802 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
803 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
804 Err(_) => panic!("Your RNG is busted"),
806 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
807 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
809 let mut rand_bytes_unique_start = Sha256::engine();
810 rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
811 rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
812 rand_bytes_unique_start.input(seed);
814 let mut res = KeysManager {
822 channel_child_index: AtomicUsize::new(0),
824 rand_bytes_master_key,
825 rand_bytes_child_index: AtomicUsize::new(0),
826 rand_bytes_unique_start,
832 let secp_seed = res.get_secure_random_bytes();
833 res.secp_ctx.seeded_randomize(&secp_seed);
836 Err(_) => panic!("Your rng is busted"),
839 /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
841 /// Key derivation parameters are accessible through a per-channel secrets
842 /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
843 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
844 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
845 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
846 assert!(chan_id <= std::u32::MAX as u64); // Otherwise the params field wasn't created by us
847 let mut unique_start = Sha256::engine();
848 unique_start.input(params);
849 unique_start.input(&self.seed);
851 // We only seriously intend to rely on the channel_master_key for true secure
852 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
853 // starting_time provided in the constructor) to be unique.
854 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(chan_id as u32).expect("key space exhausted")).expect("Your RNG is busted");
855 unique_start.input(&child_privkey.private_key.key[..]);
857 let seed = Sha256::from_engine(unique_start).into_inner();
859 let commitment_seed = {
860 let mut sha = Sha256::engine();
862 sha.input(&b"commitment seed"[..]);
863 Sha256::from_engine(sha).into_inner()
865 macro_rules! key_step {
866 ($info: expr, $prev_key: expr) => {{
867 let mut sha = Sha256::engine();
869 sha.input(&$prev_key[..]);
870 sha.input(&$info[..]);
871 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
874 let funding_key = key_step!(b"funding key", commitment_seed);
875 let revocation_base_key = key_step!(b"revocation base key", funding_key);
876 let payment_key = key_step!(b"payment key", revocation_base_key);
877 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
878 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
885 delayed_payment_base_key,
888 channel_value_satoshis,
893 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
894 /// output to the given change destination (if sufficient change value remains). The
895 /// transaction will have a feerate, at least, of the given value.
897 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
898 /// if a descriptor was duplicated.
900 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
902 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
903 /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
904 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, ()> {
905 let mut input = Vec::new();
906 let mut input_value = 0;
907 let mut witness_weight = 0;
908 let mut output_set = HashSet::with_capacity(descriptors.len());
909 for outp in descriptors {
911 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
913 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
914 script_sig: Script::new(),
918 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
919 input_value += descriptor.output.value;
920 if !output_set.insert(descriptor.outpoint) { return Err(()); }
922 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
924 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
925 script_sig: Script::new(),
926 sequence: descriptor.to_self_delay as u32,
929 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
930 input_value += descriptor.output.value;
931 if !output_set.insert(descriptor.outpoint) { return Err(()); }
933 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
935 previous_output: outpoint.into_bitcoin_outpoint(),
936 script_sig: Script::new(),
940 witness_weight += 1 + 73 + 34;
941 input_value += output.value;
942 if !output_set.insert(*outpoint) { return Err(()); }
945 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
947 let mut spend_tx = Transaction {
953 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
955 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
956 let mut input_idx = 0;
957 for outp in descriptors {
959 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
960 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
962 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
963 descriptor.channel_keys_id));
965 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
967 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
968 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
970 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
971 descriptor.channel_keys_id));
973 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
975 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
976 let derivation_idx = if output.script_pubkey == self.destination_script {
982 // Note that when we aren't serializing the key, network doesn't matter
983 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
985 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
987 Err(_) => panic!("Your RNG is busted"),
990 Err(_) => panic!("Your rng is busted"),
993 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
994 if derivation_idx == 2 {
995 assert_eq!(pubkey.key, self.shutdown_pubkey);
997 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
998 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
999 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
1000 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
1001 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
1002 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1011 impl KeysInterface for KeysManager {
1012 type Signer = InMemorySigner;
1014 fn get_node_secret(&self) -> SecretKey {
1015 self.node_secret.clone()
1018 fn get_destination_script(&self) -> Script {
1019 self.destination_script.clone()
1022 fn get_shutdown_pubkey(&self) -> PublicKey {
1023 self.shutdown_pubkey.clone()
1026 fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
1027 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1028 assert!(child_ix <= std::u32::MAX as usize);
1029 let mut id = [0; 32];
1030 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1031 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1032 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1033 self.derive_channel_keys(channel_value_satoshis, &id)
1036 fn get_secure_random_bytes(&self) -> [u8; 32] {
1037 let mut sha = self.rand_bytes_unique_start.clone();
1039 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1040 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");
1041 sha.input(&child_privkey.private_key.key[..]);
1043 sha.input(b"Unique Secure Random Bytes Salt");
1044 Sha256::from_engine(sha).into_inner()
1047 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1048 InMemorySigner::read(&mut std::io::Cursor::new(reader))