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::DynamicOutputP2WSH for more details on how to spend this.
46 #[derive(Clone, Debug, PartialEq)]
47 pub struct DynamicP2WSHOutputDescriptor {
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_pubkey used to derive witnessScript
58 pub revocation_pubkey: PublicKey,
59 /// Arbitrary identification information returned by a call to
60 /// `ChannelKeys::channel_keys_id()`. This may be useful in re-deriving keys used in
61 /// the channel to spend the output.
62 pub channel_keys_id: [u8; 32],
63 /// The value of the channel which this output originated from, possibly indirectly.
64 pub channel_value_satoshis: u64,
66 impl DynamicP2WSHOutputDescriptor {
67 /// The maximum length a well-formed witness spending one of these should have.
68 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
69 // redeemscript push length.
70 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
73 /// Information about a spendable output to our "payment key". See
74 /// SpendableOutputDescriptor::StaticOutputCounterpartyPayment for more details on how to spend this.
75 #[derive(Clone, Debug, PartialEq)]
76 pub struct StaticCounterpartyPaymentOutputDescriptor {
77 /// The outpoint which is spendable
78 pub outpoint: OutPoint,
79 /// The output which is referenced by the given outpoint
81 /// Arbitrary identification information returned by a call to
82 /// `ChannelKeys::channel_keys_id()`. This may be useful in re-deriving keys used in
83 /// the channel to spend the output.
84 pub channel_keys_id: [u8; 32],
85 /// The value of the channel which this transactions spends.
86 pub channel_value_satoshis: u64,
88 impl StaticCounterpartyPaymentOutputDescriptor {
89 /// The maximum length a well-formed witness spending one of these should have.
90 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
91 // redeemscript push length.
92 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
95 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
96 /// claim at any point in the future) an event is generated which you must track and be able to
97 /// spend on-chain. The information needed to do this is provided in this enum, including the
98 /// outpoint describing which txid and output index is available, the full output which exists at
99 /// that txid/index, and any keys or other information required to sign.
100 #[derive(Clone, Debug, PartialEq)]
101 pub enum SpendableOutputDescriptor {
102 /// An output to a script which was provided via KeysInterface directly, either from
103 /// `get_destination_script()` or `get_shutdown_pubkey()`, thus you should already know how to
104 /// spend it. No secret keys are provided as rust-lightning was never given any key.
105 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
106 /// on-chain using the payment preimage or after it has timed out.
108 /// The outpoint which is spendable
110 /// The output which is referenced by the given outpoint.
113 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
115 /// The witness in the spending input should be:
116 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
118 /// Note that the nSequence field in the spending input must be set to to_self_delay
119 /// (which means the transaction is not broadcastable until at least to_self_delay
120 /// blocks after the outpoint confirms).
122 /// These are generally the result of a "revocable" output to us, spendable only by us unless
123 /// it is an output from an old state which we broadcast (which should never happen).
125 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
126 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
127 /// ChannelKeys::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
128 /// chan_utils::derive_private_key. The public key can be generated without the secret key
129 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
130 /// ChannelKeys::pubkeys().
132 /// To derive the revocation_pubkey provided here (which is used in the witness
133 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
134 /// call to ChannelKeys::ready_channel) and the provided per_commitment point
135 /// to chan_utils::derive_public_revocation_key.
137 /// The witness script which is hashed and included in the output script_pubkey may be
138 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
139 /// (derived as above), and the to_self_delay contained here to
140 /// chan_utils::get_revokeable_redeemscript.
142 // TODO: we need to expose utility methods in KeyManager to do all the relevant derivation.
143 DynamicOutputP2WSH(DynamicP2WSHOutputDescriptor),
144 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
145 /// corresponds to the public key in ChannelKeys::pubkeys().payment_point).
146 /// The witness in the spending input, is, thus, simply:
147 /// <BIP 143 signature> <payment key>
149 /// These are generally the result of our counterparty having broadcast the current state,
150 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
151 StaticOutputCounterpartyPayment(StaticCounterpartyPaymentOutputDescriptor),
154 impl Writeable for SpendableOutputDescriptor {
155 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
157 &SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
159 outpoint.write(writer)?;
160 output.write(writer)?;
162 &SpendableOutputDescriptor::DynamicOutputP2WSH(ref descriptor) => {
164 descriptor.outpoint.write(writer)?;
165 descriptor.per_commitment_point.write(writer)?;
166 descriptor.to_self_delay.write(writer)?;
167 descriptor.output.write(writer)?;
168 descriptor.revocation_pubkey.write(writer)?;
169 descriptor.channel_keys_id.write(writer)?;
170 descriptor.channel_value_satoshis.write(writer)?;
172 &SpendableOutputDescriptor::StaticOutputCounterpartyPayment(ref descriptor) => {
174 descriptor.outpoint.write(writer)?;
175 descriptor.output.write(writer)?;
176 descriptor.channel_keys_id.write(writer)?;
177 descriptor.channel_value_satoshis.write(writer)?;
184 impl Readable for SpendableOutputDescriptor {
185 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
186 match Readable::read(reader)? {
187 0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
188 outpoint: Readable::read(reader)?,
189 output: Readable::read(reader)?,
191 1u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WSH(DynamicP2WSHOutputDescriptor {
192 outpoint: Readable::read(reader)?,
193 per_commitment_point: Readable::read(reader)?,
194 to_self_delay: Readable::read(reader)?,
195 output: Readable::read(reader)?,
196 revocation_pubkey: Readable::read(reader)?,
197 channel_keys_id: Readable::read(reader)?,
198 channel_value_satoshis: Readable::read(reader)?,
200 2u8 => Ok(SpendableOutputDescriptor::StaticOutputCounterpartyPayment(StaticCounterpartyPaymentOutputDescriptor {
201 outpoint: Readable::read(reader)?,
202 output: Readable::read(reader)?,
203 channel_keys_id: Readable::read(reader)?,
204 channel_value_satoshis: Readable::read(reader)?,
206 _ => Err(DecodeError::InvalidValue),
211 /// Set of lightning keys needed to operate a channel as described in BOLT 3.
213 /// Signing services could be implemented on a hardware wallet. In this case,
214 /// the current ChannelKeys would be a front-end on top of a communication
215 /// channel connected to your secure device and lightning key material wouldn't
216 /// reside on a hot server. Nevertheless, a this deployment would still need
217 /// to trust the ChannelManager to avoid loss of funds as this latest component
218 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
220 /// A more secure iteration would be to use hashlock (or payment points) to pair
221 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
222 /// at the price of more state and computation on the hardware wallet side. In the future,
223 /// we are looking forward to design such interface.
225 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
226 /// to act, as liveness and breach reply correctness are always going to be hard requirements
227 /// of LN security model, orthogonal of key management issues.
229 /// If you're implementing a custom signer, you almost certainly want to implement
230 /// Readable/Writable to serialize out a unique reference to this set of keys so
231 /// that you can serialize the full ChannelManager object.
233 // (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly
234 // to the possibility of reentrancy issues by calling the user's code during our deserialization
236 // TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
237 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
238 pub trait ChannelKeys : Send+Clone + Writeable {
239 /// Gets the per-commitment point for a specific commitment number
241 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
242 fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey;
243 /// Gets the commitment secret for a specific commitment number as part of the revocation process
245 /// An external signer implementation should error here if the commitment was already signed
246 /// and should refuse to sign it in the future.
248 /// May be called more than once for the same index.
250 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
251 /// TODO: return a Result so we can signal a validation error
252 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
253 /// Gets the holder's channel public keys and basepoints
254 fn pubkeys(&self) -> &ChannelPublicKeys;
255 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
256 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
257 /// ChannelKeys object uniquely and lookup or re-derive its keys.
258 fn channel_keys_id(&self) -> [u8; 32];
260 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
262 /// Note that if signing fails or is rejected, the channel will be force-closed.
264 // TODO: Document the things someone using this interface should enforce before signing.
265 fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
267 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
268 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
269 /// latest commitment_tx when we initiate a force-close.
270 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
271 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
273 /// This may be called multiple times for the same transaction.
275 /// An external signer implementation should check that the commitment has not been revoked.
277 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
279 // TODO: Document the things someone using this interface should enforce before signing.
280 // TODO: Key derivation failure should panic rather than Err
281 fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
283 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
284 /// transactions which will be broadcasted later, after the channel has moved on to a newer
285 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
287 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
288 fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
290 /// Create a signature for the given input in a transaction spending an HTLC or commitment
291 /// transaction output when our counterparty broadcasts an old state.
293 /// A justice transaction may claim multiples outputs at the same time if timelocks are
294 /// similar, but only a signature for the input at index `input` should be signed for here.
295 /// It may be called multiples time for same output(s) if a fee-bump is needed with regards
296 /// to an upcoming timelock expiration.
298 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
300 /// per_commitment_key is revocation secret which was provided by our counterparty when they
301 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
302 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
305 /// htlc holds HTLC elements (hash, timelock) if the output being spent is a HTLC output, thus
306 /// changing the format of the witness script (which is committed to in the BIP 143
308 fn sign_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
310 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
311 /// transaction, either offered or received.
313 /// Such a transaction may claim multiples offered outputs at same time if we know the
314 /// preimage for each when we create it, but only the input at index `input` should be
315 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
316 /// needed with regards to an upcoming timelock expiration.
318 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
321 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
323 /// Per_commitment_point is the dynamic point corresponding to the channel state
324 /// detected onchain. It has been generated by our counterparty and is used to derive
325 /// channel state keys, which are then included in the witness script and committed to in the
326 /// BIP 143 signature.
327 fn sign_counterparty_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
329 /// Create a signature for a (proposed) closing transaction.
331 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
332 /// chosen to forgo their output as dust.
333 fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
335 /// Signs a channel announcement message with our funding key, proving it comes from one
336 /// of the channel participants.
338 /// Note that if this fails or is rejected, the channel will not be publicly announced and
339 /// our counterparty may (though likely will not) close the channel on us for violating the
341 fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
343 /// Set the counterparty static channel data, including basepoints,
344 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
345 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
346 /// they MUST NOT be allowed to change to different values once set.
348 /// channel_parameters.is_populated() MUST be true.
350 /// We bind holder_selected_contest_delay late here for API convenience.
352 /// Will be called before any signatures are applied.
353 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
356 /// A trait to describe an object which can get user secrets and key material.
357 pub trait KeysInterface: Send + Sync {
358 /// A type which implements ChannelKeys which will be returned by get_channel_keys.
359 type ChanKeySigner : ChannelKeys;
361 /// Get node secret key (aka node_id or network_key).
363 /// This method must return the same value each time it is called.
364 fn get_node_secret(&self) -> SecretKey;
365 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
367 /// This method should return a different value each time it is called, to avoid linking
368 /// on-chain funds across channels as controlled to the same user.
369 fn get_destination_script(&self) -> Script;
370 /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
373 /// This method should return a different value each time it is called, to avoid linking
374 /// on-chain funds across channels as controlled to the same user.
375 fn get_shutdown_pubkey(&self) -> PublicKey;
376 /// Get a new set of ChannelKeys for per-channel secrets. These MUST be unique even if you
377 /// restarted with some stale data!
379 /// This method must return a different value each time it is called.
380 fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner;
381 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
382 /// onion packets and for temporary channel IDs. There is no requirement that these be
383 /// persisted anywhere, though they must be unique across restarts.
385 /// This method must return a different value each time it is called.
386 fn get_secure_random_bytes(&self) -> [u8; 32];
388 /// Reads a `ChanKeySigner` for this `KeysInterface` from the given input stream.
389 /// This is only called during deserialization of other objects which contain
390 /// `ChannelKeys`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
391 /// The bytes are exactly those which `<Self::ChanKeySigner as Writeable>::write()` writes, and
392 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
393 /// you've read all of the provided bytes to ensure no corruption occurred.
394 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError>;
398 /// A simple implementation of ChannelKeys that just keeps the private keys in memory.
400 /// This implementation performs no policy checks and is insufficient by itself as
401 /// a secure external signer.
402 pub struct InMemoryChannelKeys {
403 /// Private key of anchor tx
404 pub funding_key: SecretKey,
405 /// Holder secret key for blinded revocation pubkey
406 pub revocation_base_key: SecretKey,
407 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
408 pub payment_key: SecretKey,
409 /// Holder secret key used in HTLC tx
410 pub delayed_payment_base_key: SecretKey,
411 /// Holder htlc secret key used in commitment tx htlc outputs
412 pub htlc_base_key: SecretKey,
414 pub commitment_seed: [u8; 32],
415 /// Holder public keys and basepoints
416 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
417 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
418 channel_parameters: Option<ChannelTransactionParameters>,
419 /// The total value of this channel
420 channel_value_satoshis: u64,
421 /// Key derivation parameters
422 channel_keys_id: [u8; 32],
425 impl InMemoryChannelKeys {
426 /// Create a new InMemoryChannelKeys
427 pub fn new<C: Signing>(
428 secp_ctx: &Secp256k1<C>,
429 funding_key: SecretKey,
430 revocation_base_key: SecretKey,
431 payment_key: SecretKey,
432 delayed_payment_base_key: SecretKey,
433 htlc_base_key: SecretKey,
434 commitment_seed: [u8; 32],
435 channel_value_satoshis: u64,
436 channel_keys_id: [u8; 32]) -> InMemoryChannelKeys {
437 let holder_channel_pubkeys =
438 InMemoryChannelKeys::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
439 &payment_key, &delayed_payment_base_key,
441 InMemoryChannelKeys {
445 delayed_payment_base_key,
448 channel_value_satoshis,
449 holder_channel_pubkeys,
450 channel_parameters: None,
455 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
456 funding_key: &SecretKey,
457 revocation_base_key: &SecretKey,
458 payment_key: &SecretKey,
459 delayed_payment_base_key: &SecretKey,
460 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
461 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
463 funding_pubkey: from_secret(&funding_key),
464 revocation_basepoint: from_secret(&revocation_base_key),
465 payment_point: from_secret(&payment_key),
466 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
467 htlc_basepoint: from_secret(&htlc_base_key),
471 /// Counterparty pubkeys.
472 /// Will panic if ready_channel wasn't called.
473 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
475 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
476 /// transactions, ie the amount of time that we have to wait to recover our funds if we
477 /// broadcast a transaction.
478 /// Will panic if ready_channel wasn't called.
479 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
481 /// The contest_delay value specified by us and applied on transactions broadcastable
482 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
483 /// if they broadcast a transaction.
484 /// Will panic if ready_channel wasn't called.
485 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
487 /// Whether the holder is the initiator
488 /// Will panic if ready_channel wasn't called.
489 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
492 /// Will panic if ready_channel wasn't called.
493 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
495 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
496 /// building transactions.
498 /// Will panic if ready_channel wasn't called.
499 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
500 self.channel_parameters.as_ref().unwrap()
503 /// Sign the single input of spend_tx at index `input_idx` which spends the output
504 /// described by descriptor, returning the witness stack for the input.
506 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
507 /// or is not spending the outpoint described by `descriptor.outpoint`.
508 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticCounterpartyPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
509 // TODO: We really should be taking the SigHashCache as a parameter here instead of
510 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
511 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
512 // bindings updates to support SigHashCache objects).
513 if spend_tx.input.len() <= input_idx { return Err(()); }
514 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
515 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
517 let remotepubkey = self.pubkeys().payment_point;
518 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
519 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
520 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
522 let mut witness = Vec::with_capacity(2);
523 witness.push(remotesig.serialize_der().to_vec());
524 witness[0].push(SigHashType::All as u8);
525 witness.push(remotepubkey.serialize().to_vec());
529 /// Sign the single input of spend_tx at index `input_idx` which spends the output
530 /// described by descriptor, returning the witness stack for the input.
532 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
533 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
534 /// sequence set to `descriptor.to_self_delay`.
535 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DynamicP2WSHOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
536 // TODO: We really should be taking the SigHashCache as a parameter here instead of
537 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
538 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
539 // bindings updates to support SigHashCache objects).
540 if spend_tx.input.len() <= input_idx { return Err(()); }
541 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
542 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
543 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
545 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
546 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
547 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
548 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
549 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
550 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
552 let mut witness = Vec::with_capacity(3);
553 witness.push(local_delayedsig.serialize_der().to_vec());
554 witness[0].push(SigHashType::All as u8);
555 witness.push(vec!()); //MINIMALIF
556 witness.push(witness_script.clone().into_bytes());
561 impl ChannelKeys for InMemoryChannelKeys {
562 fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey {
563 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
564 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
567 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
568 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
571 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
572 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
574 fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
575 let trusted_tx = commitment_tx.trust();
576 let keys = trusted_tx.keys();
578 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
579 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
581 let built_tx = trusted_tx.built_transaction();
582 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
583 let commitment_txid = built_tx.txid;
585 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
586 for htlc in commitment_tx.htlcs() {
587 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);
588 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
589 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
590 let holder_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) {
592 Err(_) => return Err(()),
594 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
597 Ok((commitment_sig, htlc_sigs))
600 fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
601 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
602 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
603 let trusted_tx = commitment_tx.trust();
604 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
605 let channel_parameters = self.get_channel_parameters();
606 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
610 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
611 fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
612 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
613 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
614 let trusted_tx = commitment_tx.trust();
615 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
616 let channel_parameters = self.get_channel_parameters();
617 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
621 fn sign_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
622 let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
623 Ok(revocation_key) => revocation_key,
624 Err(_) => return Err(())
626 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
627 let revocation_pubkey = match chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
628 Ok(revocation_pubkey) => revocation_pubkey,
629 Err(_) => return Err(())
631 let witness_script = if let &Some(ref htlc) = htlc {
632 let counterparty_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
633 Ok(counterparty_htlcpubkey) => counterparty_htlcpubkey,
634 Err(_) => return Err(())
636 let holder_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
637 Ok(holder_htlcpubkey) => holder_htlcpubkey,
638 Err(_) => return Err(())
640 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
642 let counterparty_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint) {
643 Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey,
644 Err(_) => return Err(())
646 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
648 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
649 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
650 return Ok(secp_ctx.sign(&sighash, &revocation_key))
653 fn sign_counterparty_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
654 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
655 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
656 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
657 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
658 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
659 } else { return Err(()) }
660 } else { return Err(()) }
661 } else { return Err(()) };
662 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
663 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
664 return Ok(secp_ctx.sign(&sighash, &htlc_key))
669 fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
670 if closing_tx.input.len() != 1 { return Err(()); }
671 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
672 if closing_tx.output.len() > 2 { return Err(()); }
674 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
675 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
677 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
678 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
679 Ok(secp_ctx.sign(&sighash, &self.funding_key))
682 fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
683 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
684 Ok(secp_ctx.sign(&msghash, &self.funding_key))
687 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
688 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
689 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
690 self.channel_parameters = Some(channel_parameters.clone());
694 impl Writeable for InMemoryChannelKeys {
695 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
696 self.funding_key.write(writer)?;
697 self.revocation_base_key.write(writer)?;
698 self.payment_key.write(writer)?;
699 self.delayed_payment_base_key.write(writer)?;
700 self.htlc_base_key.write(writer)?;
701 self.commitment_seed.write(writer)?;
702 self.channel_parameters.write(writer)?;
703 self.channel_value_satoshis.write(writer)?;
704 self.channel_keys_id.write(writer)?;
710 impl Readable for InMemoryChannelKeys {
711 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
712 let funding_key = Readable::read(reader)?;
713 let revocation_base_key = Readable::read(reader)?;
714 let payment_key = Readable::read(reader)?;
715 let delayed_payment_base_key = Readable::read(reader)?;
716 let htlc_base_key = Readable::read(reader)?;
717 let commitment_seed = Readable::read(reader)?;
718 let counterparty_channel_data = Readable::read(reader)?;
719 let channel_value_satoshis = Readable::read(reader)?;
720 let secp_ctx = Secp256k1::signing_only();
721 let holder_channel_pubkeys =
722 InMemoryChannelKeys::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
723 &payment_key, &delayed_payment_base_key,
725 let keys_id = Readable::read(reader)?;
727 Ok(InMemoryChannelKeys {
731 delayed_payment_base_key,
734 channel_value_satoshis,
735 holder_channel_pubkeys,
736 channel_parameters: counterparty_channel_data,
737 channel_keys_id: keys_id,
742 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
743 /// and derives keys from that.
745 /// Your node_id is seed/0'
746 /// ChannelMonitor closes may use seed/1'
747 /// Cooperative closes may use seed/2'
748 /// The two close keys may be needed to claim on-chain funds!
749 pub struct KeysManager {
750 secp_ctx: Secp256k1<secp256k1::SignOnly>,
751 node_secret: SecretKey,
752 destination_script: Script,
753 shutdown_pubkey: PublicKey,
754 channel_master_key: ExtendedPrivKey,
755 channel_child_index: AtomicUsize,
756 rand_bytes_master_key: ExtendedPrivKey,
757 rand_bytes_child_index: AtomicUsize,
760 starting_time_secs: u64,
761 starting_time_nanos: u32,
765 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
766 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
767 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
768 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
769 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
770 /// simply use the current time (with very high precision).
772 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
773 /// obviously, starting_time should be unique every time you reload the library - it is only
774 /// used to generate new ephemeral key data (which will be stored by the individual channel if
777 /// Note that the seed is required to recover certain on-chain funds independent of
778 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
779 /// channel, and some on-chain during-closing funds.
781 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
782 /// versions. Once the library is more fully supported, the docs will be updated to include a
783 /// detailed description of the guarantee.
784 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
785 let secp_ctx = Secp256k1::signing_only();
786 // Note that when we aren't serializing the key, network doesn't matter
787 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
789 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
790 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
791 Ok(destination_key) => {
792 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
793 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
794 .push_slice(&wpubkey_hash.into_inner())
797 Err(_) => panic!("Your RNG is busted"),
799 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
800 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
801 Err(_) => panic!("Your RNG is busted"),
803 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
804 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
812 channel_child_index: AtomicUsize::new(0),
813 rand_bytes_master_key,
814 rand_bytes_child_index: AtomicUsize::new(0),
821 Err(_) => panic!("Your rng is busted"),
824 fn derive_unique_start(&self) -> Sha256State {
825 let mut unique_start = Sha256::engine();
826 unique_start.input(&byte_utils::be64_to_array(self.starting_time_secs));
827 unique_start.input(&byte_utils::be32_to_array(self.starting_time_nanos));
828 unique_start.input(&self.seed);
831 /// Derive an old set of ChannelKeys for per-channel secrets based on a key derivation
833 /// Key derivation parameters are accessible through a per-channel secrets
834 /// ChannelKeys::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
835 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
836 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemoryChannelKeys {
837 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
838 assert!(chan_id <= std::u32::MAX as u64); // Otherwise the params field wasn't created by us
839 let mut unique_start = Sha256::engine();
840 unique_start.input(params);
841 unique_start.input(&self.seed);
843 // We only seriously intend to rely on the channel_master_key for true secure
844 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
845 // starting_time provided in the constructor) to be unique.
846 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");
847 unique_start.input(&child_privkey.private_key.key[..]);
849 let seed = Sha256::from_engine(unique_start).into_inner();
851 let commitment_seed = {
852 let mut sha = Sha256::engine();
854 sha.input(&b"commitment seed"[..]);
855 Sha256::from_engine(sha).into_inner()
857 macro_rules! key_step {
858 ($info: expr, $prev_key: expr) => {{
859 let mut sha = Sha256::engine();
861 sha.input(&$prev_key[..]);
862 sha.input(&$info[..]);
863 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
866 let funding_key = key_step!(b"funding key", commitment_seed);
867 let revocation_base_key = key_step!(b"revocation base key", funding_key);
868 let payment_key = key_step!(b"payment key", revocation_base_key);
869 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
870 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
872 InMemoryChannelKeys::new(
877 delayed_payment_base_key,
880 channel_value_satoshis,
885 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
886 /// output to the given change destination (if sufficient change value remains). The
887 /// transaction will have a feerate, at least, of the given value.
889 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
890 /// if a descriptor was duplicated.
892 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
894 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
895 /// this KeysManager or one of the `InMemoryChannelKeys` created by this KeysManager.
896 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, ()> {
897 let mut input = Vec::new();
898 let mut input_value = 0;
899 let mut witness_weight = 0;
900 let mut output_set = HashSet::with_capacity(descriptors.len());
901 for outp in descriptors {
903 SpendableOutputDescriptor::StaticOutputCounterpartyPayment(descriptor) => {
905 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
906 script_sig: Script::new(),
910 witness_weight += StaticCounterpartyPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
911 input_value += descriptor.output.value;
912 if !output_set.insert(descriptor.outpoint) { return Err(()); }
914 SpendableOutputDescriptor::DynamicOutputP2WSH(descriptor) => {
916 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
917 script_sig: Script::new(),
918 sequence: descriptor.to_self_delay as u32,
921 witness_weight += DynamicP2WSHOutputDescriptor::MAX_WITNESS_LENGTH;
922 input_value += descriptor.output.value;
923 if !output_set.insert(descriptor.outpoint) { return Err(()); }
925 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
927 previous_output: outpoint.into_bitcoin_outpoint(),
928 script_sig: Script::new(),
932 witness_weight += 1 + 73 + 34;
933 input_value += output.value;
934 if !output_set.insert(*outpoint) { return Err(()); }
937 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
939 let mut spend_tx = Transaction {
945 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
947 let mut keys_cache: Option<(InMemoryChannelKeys, [u8; 32])> = None;
948 let mut input_idx = 0;
949 for outp in descriptors {
951 SpendableOutputDescriptor::StaticOutputCounterpartyPayment(descriptor) => {
952 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
954 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
955 descriptor.channel_keys_id));
957 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
959 SpendableOutputDescriptor::DynamicOutputP2WSH(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_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
967 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
968 let derivation_idx = if output.script_pubkey == self.destination_script {
974 // Note that when we aren't serializing the key, network doesn't matter
975 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
977 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
979 Err(_) => panic!("Your RNG is busted"),
982 Err(_) => panic!("Your rng is busted"),
985 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
986 if derivation_idx == 2 {
987 assert_eq!(pubkey.key, self.shutdown_pubkey);
989 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
990 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
991 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
992 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
993 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
994 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1003 impl KeysInterface for KeysManager {
1004 type ChanKeySigner = InMemoryChannelKeys;
1006 fn get_node_secret(&self) -> SecretKey {
1007 self.node_secret.clone()
1010 fn get_destination_script(&self) -> Script {
1011 self.destination_script.clone()
1014 fn get_shutdown_pubkey(&self) -> PublicKey {
1015 self.shutdown_pubkey.clone()
1018 fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner {
1019 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1020 assert!(child_ix <= std::u32::MAX as usize);
1021 let mut id = [0; 32];
1022 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1023 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1024 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1025 self.derive_channel_keys(channel_value_satoshis, &id)
1028 fn get_secure_random_bytes(&self) -> [u8; 32] {
1029 let mut sha = self.derive_unique_start();
1031 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1032 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");
1033 sha.input(&child_privkey.private_key.key[..]);
1035 sha.input(b"Unique Secure Random Bytes Salt");
1036 Sha256::from_engine(sha).into_inner()
1039 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError> {
1040 InMemoryChannelKeys::read(&mut std::io::Cursor::new(reader))