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.
141 DynamicOutputP2WSH(DynamicP2WSHOutputDescriptor),
142 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
143 /// corresponds to the public key in ChannelKeys::pubkeys().payment_point).
144 /// The witness in the spending input, is, thus, simply:
145 /// <BIP 143 signature> <payment key>
147 /// These are generally the result of our counterparty having broadcast the current state,
148 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
149 StaticOutputCounterpartyPayment(StaticCounterpartyPaymentOutputDescriptor),
152 impl Writeable for SpendableOutputDescriptor {
153 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
155 &SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
157 outpoint.write(writer)?;
158 output.write(writer)?;
160 &SpendableOutputDescriptor::DynamicOutputP2WSH(ref descriptor) => {
162 descriptor.outpoint.write(writer)?;
163 descriptor.per_commitment_point.write(writer)?;
164 descriptor.to_self_delay.write(writer)?;
165 descriptor.output.write(writer)?;
166 descriptor.revocation_pubkey.write(writer)?;
167 descriptor.channel_keys_id.write(writer)?;
168 descriptor.channel_value_satoshis.write(writer)?;
170 &SpendableOutputDescriptor::StaticOutputCounterpartyPayment(ref descriptor) => {
172 descriptor.outpoint.write(writer)?;
173 descriptor.output.write(writer)?;
174 descriptor.channel_keys_id.write(writer)?;
175 descriptor.channel_value_satoshis.write(writer)?;
182 impl Readable for SpendableOutputDescriptor {
183 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
184 match Readable::read(reader)? {
185 0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
186 outpoint: Readable::read(reader)?,
187 output: Readable::read(reader)?,
189 1u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WSH(DynamicP2WSHOutputDescriptor {
190 outpoint: Readable::read(reader)?,
191 per_commitment_point: Readable::read(reader)?,
192 to_self_delay: Readable::read(reader)?,
193 output: Readable::read(reader)?,
194 revocation_pubkey: Readable::read(reader)?,
195 channel_keys_id: Readable::read(reader)?,
196 channel_value_satoshis: Readable::read(reader)?,
198 2u8 => Ok(SpendableOutputDescriptor::StaticOutputCounterpartyPayment(StaticCounterpartyPaymentOutputDescriptor {
199 outpoint: Readable::read(reader)?,
200 output: Readable::read(reader)?,
201 channel_keys_id: Readable::read(reader)?,
202 channel_value_satoshis: Readable::read(reader)?,
204 _ => Err(DecodeError::InvalidValue),
209 /// Set of lightning keys needed to operate a channel as described in BOLT 3.
211 /// Signing services could be implemented on a hardware wallet. In this case,
212 /// the current ChannelKeys would be a front-end on top of a communication
213 /// channel connected to your secure device and lightning key material wouldn't
214 /// reside on a hot server. Nevertheless, a this deployment would still need
215 /// to trust the ChannelManager to avoid loss of funds as this latest component
216 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
218 /// A more secure iteration would be to use hashlock (or payment points) to pair
219 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
220 /// at the price of more state and computation on the hardware wallet side. In the future,
221 /// we are looking forward to design such interface.
223 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
224 /// to act, as liveness and breach reply correctness are always going to be hard requirements
225 /// of LN security model, orthogonal of key management issues.
226 // TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
227 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
228 pub trait ChannelKeys : Send+Clone + Writeable {
229 /// Gets the per-commitment point for a specific commitment number
231 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
232 fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey;
233 /// Gets the commitment secret for a specific commitment number as part of the revocation process
235 /// An external signer implementation should error here if the commitment was already signed
236 /// and should refuse to sign it in the future.
238 /// May be called more than once for the same index.
240 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
241 // TODO: return a Result so we can signal a validation error
242 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
243 /// Gets the holder's channel public keys and basepoints
244 fn pubkeys(&self) -> &ChannelPublicKeys;
245 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
246 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
247 /// ChannelKeys object uniquely and lookup or re-derive its keys.
248 fn channel_keys_id(&self) -> [u8; 32];
250 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
252 /// Note that if signing fails or is rejected, the channel will be force-closed.
254 // TODO: Document the things someone using this interface should enforce before signing.
255 fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
257 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
258 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
259 /// latest commitment_tx when we initiate a force-close.
260 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
261 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
263 /// This may be called multiple times for the same transaction.
265 /// An external signer implementation should check that the commitment has not been revoked.
267 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
269 // TODO: Document the things someone using this interface should enforce before signing.
270 // TODO: Key derivation failure should panic rather than Err
271 fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
273 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
274 /// transactions which will be broadcasted later, after the channel has moved on to a newer
275 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
277 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
278 fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
280 /// Create a signature for the given input in a transaction spending an HTLC or commitment
281 /// transaction output when our counterparty broadcasts an old state.
283 /// A justice transaction may claim multiples outputs at the same time if timelocks are
284 /// similar, but only a signature for the input at index `input` should be signed for here.
285 /// It may be called multiples time for same output(s) if a fee-bump is needed with regards
286 /// to an upcoming timelock expiration.
288 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
290 /// per_commitment_key is revocation secret which was provided by our counterparty when they
291 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
292 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
295 /// htlc holds HTLC elements (hash, timelock) if the output being spent is a HTLC output, thus
296 /// changing the format of the witness script (which is committed to in the BIP 143
298 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, ()>;
300 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
301 /// transaction, either offered or received.
303 /// Such a transaction may claim multiples offered outputs at same time if we know the
304 /// preimage for each when we create it, but only the input at index `input` should be
305 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
306 /// needed with regards to an upcoming timelock expiration.
308 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
311 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
313 /// Per_commitment_point is the dynamic point corresponding to the channel state
314 /// detected onchain. It has been generated by our counterparty and is used to derive
315 /// channel state keys, which are then included in the witness script and committed to in the
316 /// BIP 143 signature.
317 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, ()>;
319 /// Create a signature for a (proposed) closing transaction.
321 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
322 /// chosen to forgo their output as dust.
323 fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
325 /// Signs a channel announcement message with our funding key, proving it comes from one
326 /// of the channel participants.
328 /// Note that if this fails or is rejected, the channel will not be publicly announced and
329 /// our counterparty may (though likely will not) close the channel on us for violating the
331 fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
333 /// Set the counterparty static channel data, including basepoints,
334 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
335 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
336 /// they MUST NOT be allowed to change to different values once set.
338 /// channel_parameters.is_populated() MUST be true.
340 /// We bind holder_selected_contest_delay late here for API convenience.
342 /// Will be called before any signatures are applied.
343 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
346 /// A trait to describe an object which can get user secrets and key material.
347 pub trait KeysInterface: Send + Sync {
348 /// A type which implements ChannelKeys which will be returned by get_channel_keys.
349 type ChanKeySigner : ChannelKeys;
351 /// Get node secret key (aka node_id or network_key).
353 /// This method must return the same value each time it is called.
354 fn get_node_secret(&self) -> SecretKey;
355 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
357 /// This method should return a different value each time it is called, to avoid linking
358 /// on-chain funds across channels as controlled to the same user.
359 fn get_destination_script(&self) -> Script;
360 /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
363 /// This method should return a different value each time it is called, to avoid linking
364 /// on-chain funds across channels as controlled to the same user.
365 fn get_shutdown_pubkey(&self) -> PublicKey;
366 /// Get a new set of ChannelKeys for per-channel secrets. These MUST be unique even if you
367 /// restarted with some stale data!
369 /// This method must return a different value each time it is called.
370 fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner;
371 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
372 /// onion packets and for temporary channel IDs. There is no requirement that these be
373 /// persisted anywhere, though they must be unique across restarts.
375 /// This method must return a different value each time it is called.
376 fn get_secure_random_bytes(&self) -> [u8; 32];
378 /// Reads a `ChanKeySigner` for this `KeysInterface` from the given input stream.
379 /// This is only called during deserialization of other objects which contain
380 /// `ChannelKeys`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
381 /// The bytes are exactly those which `<Self::ChanKeySigner as Writeable>::write()` writes, and
382 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
383 /// you've read all of the provided bytes to ensure no corruption occurred.
384 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError>;
388 /// A simple implementation of ChannelKeys that just keeps the private keys in memory.
390 /// This implementation performs no policy checks and is insufficient by itself as
391 /// a secure external signer.
392 pub struct InMemoryChannelKeys {
393 /// Private key of anchor tx
394 pub funding_key: SecretKey,
395 /// Holder secret key for blinded revocation pubkey
396 pub revocation_base_key: SecretKey,
397 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
398 pub payment_key: SecretKey,
399 /// Holder secret key used in HTLC tx
400 pub delayed_payment_base_key: SecretKey,
401 /// Holder htlc secret key used in commitment tx htlc outputs
402 pub htlc_base_key: SecretKey,
404 pub commitment_seed: [u8; 32],
405 /// Holder public keys and basepoints
406 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
407 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
408 channel_parameters: Option<ChannelTransactionParameters>,
409 /// The total value of this channel
410 channel_value_satoshis: u64,
411 /// Key derivation parameters
412 channel_keys_id: [u8; 32],
415 impl InMemoryChannelKeys {
416 /// Create a new InMemoryChannelKeys
417 pub fn new<C: Signing>(
418 secp_ctx: &Secp256k1<C>,
419 funding_key: SecretKey,
420 revocation_base_key: SecretKey,
421 payment_key: SecretKey,
422 delayed_payment_base_key: SecretKey,
423 htlc_base_key: SecretKey,
424 commitment_seed: [u8; 32],
425 channel_value_satoshis: u64,
426 channel_keys_id: [u8; 32]) -> InMemoryChannelKeys {
427 let holder_channel_pubkeys =
428 InMemoryChannelKeys::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
429 &payment_key, &delayed_payment_base_key,
431 InMemoryChannelKeys {
435 delayed_payment_base_key,
438 channel_value_satoshis,
439 holder_channel_pubkeys,
440 channel_parameters: None,
445 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
446 funding_key: &SecretKey,
447 revocation_base_key: &SecretKey,
448 payment_key: &SecretKey,
449 delayed_payment_base_key: &SecretKey,
450 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
451 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
453 funding_pubkey: from_secret(&funding_key),
454 revocation_basepoint: from_secret(&revocation_base_key),
455 payment_point: from_secret(&payment_key),
456 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
457 htlc_basepoint: from_secret(&htlc_base_key),
461 /// Counterparty pubkeys.
462 /// Will panic if ready_channel wasn't called.
463 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
465 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
466 /// transactions, ie the amount of time that we have to wait to recover our funds if we
467 /// broadcast a transaction.
468 /// Will panic if ready_channel wasn't called.
469 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
471 /// The contest_delay value specified by us and applied on transactions broadcastable
472 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
473 /// if they broadcast a transaction.
474 /// Will panic if ready_channel wasn't called.
475 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
477 /// Whether the holder is the initiator
478 /// Will panic if ready_channel wasn't called.
479 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
482 /// Will panic if ready_channel wasn't called.
483 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
485 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
486 /// building transactions.
488 /// Will panic if ready_channel wasn't called.
489 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
490 self.channel_parameters.as_ref().unwrap()
493 /// Sign the single input of spend_tx at index `input_idx` which spends the output
494 /// described by descriptor, returning the witness stack for the input.
496 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
497 /// or is not spending the outpoint described by `descriptor.outpoint`.
498 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>>, ()> {
499 // TODO: We really should be taking the SigHashCache as a parameter here instead of
500 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
501 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
502 // bindings updates to support SigHashCache objects).
503 if spend_tx.input.len() <= input_idx { return Err(()); }
504 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
505 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
507 let remotepubkey = self.pubkeys().payment_point;
508 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
509 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
510 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
512 let mut witness = Vec::with_capacity(2);
513 witness.push(remotesig.serialize_der().to_vec());
514 witness[0].push(SigHashType::All as u8);
515 witness.push(remotepubkey.serialize().to_vec());
519 /// Sign the single input of spend_tx at index `input_idx` which spends the output
520 /// described by descriptor, returning the witness stack for the input.
522 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
523 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
524 /// sequence set to `descriptor.to_self_delay`.
525 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>>, ()> {
526 // TODO: We really should be taking the SigHashCache as a parameter here instead of
527 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
528 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
529 // bindings updates to support SigHashCache objects).
530 if spend_tx.input.len() <= input_idx { return Err(()); }
531 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
532 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
533 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
535 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
536 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
537 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
538 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
539 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
540 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
542 let mut witness = Vec::with_capacity(3);
543 witness.push(local_delayedsig.serialize_der().to_vec());
544 witness[0].push(SigHashType::All as u8);
545 witness.push(vec!()); //MINIMALIF
546 witness.push(witness_script.clone().into_bytes());
551 impl ChannelKeys for InMemoryChannelKeys {
552 fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey {
553 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
554 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
557 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
558 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
561 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
562 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
564 fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
565 let trusted_tx = commitment_tx.trust();
566 let keys = trusted_tx.keys();
568 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
569 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
571 let built_tx = trusted_tx.built_transaction();
572 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
573 let commitment_txid = built_tx.txid;
575 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
576 for htlc in commitment_tx.htlcs() {
577 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);
578 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
579 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
580 let holder_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) {
582 Err(_) => return Err(()),
584 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
587 Ok((commitment_sig, htlc_sigs))
590 fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
591 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
592 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
593 let trusted_tx = commitment_tx.trust();
594 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
595 let channel_parameters = self.get_channel_parameters();
596 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
600 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
601 fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
602 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
603 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
604 let trusted_tx = commitment_tx.trust();
605 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
606 let channel_parameters = self.get_channel_parameters();
607 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
611 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, ()> {
612 let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
613 Ok(revocation_key) => revocation_key,
614 Err(_) => return Err(())
616 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
617 let revocation_pubkey = match chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
618 Ok(revocation_pubkey) => revocation_pubkey,
619 Err(_) => return Err(())
621 let witness_script = if let &Some(ref htlc) = htlc {
622 let counterparty_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
623 Ok(counterparty_htlcpubkey) => counterparty_htlcpubkey,
624 Err(_) => return Err(())
626 let holder_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
627 Ok(holder_htlcpubkey) => holder_htlcpubkey,
628 Err(_) => return Err(())
630 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
632 let counterparty_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint) {
633 Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey,
634 Err(_) => return Err(())
636 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
638 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
639 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
640 return Ok(secp_ctx.sign(&sighash, &revocation_key))
643 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, ()> {
644 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
645 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
646 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
647 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
648 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
649 } else { return Err(()) }
650 } else { return Err(()) }
651 } else { return Err(()) };
652 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
653 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
654 return Ok(secp_ctx.sign(&sighash, &htlc_key))
659 fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
660 if closing_tx.input.len() != 1 { return Err(()); }
661 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
662 if closing_tx.output.len() > 2 { return Err(()); }
664 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
665 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
667 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
668 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
669 Ok(secp_ctx.sign(&sighash, &self.funding_key))
672 fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
673 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
674 Ok(secp_ctx.sign(&msghash, &self.funding_key))
677 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
678 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
679 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
680 self.channel_parameters = Some(channel_parameters.clone());
684 impl Writeable for InMemoryChannelKeys {
685 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
686 self.funding_key.write(writer)?;
687 self.revocation_base_key.write(writer)?;
688 self.payment_key.write(writer)?;
689 self.delayed_payment_base_key.write(writer)?;
690 self.htlc_base_key.write(writer)?;
691 self.commitment_seed.write(writer)?;
692 self.channel_parameters.write(writer)?;
693 self.channel_value_satoshis.write(writer)?;
694 self.channel_keys_id.write(writer)?;
700 impl Readable for InMemoryChannelKeys {
701 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
702 let funding_key = Readable::read(reader)?;
703 let revocation_base_key = Readable::read(reader)?;
704 let payment_key = Readable::read(reader)?;
705 let delayed_payment_base_key = Readable::read(reader)?;
706 let htlc_base_key = Readable::read(reader)?;
707 let commitment_seed = Readable::read(reader)?;
708 let counterparty_channel_data = Readable::read(reader)?;
709 let channel_value_satoshis = Readable::read(reader)?;
710 let secp_ctx = Secp256k1::signing_only();
711 let holder_channel_pubkeys =
712 InMemoryChannelKeys::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
713 &payment_key, &delayed_payment_base_key,
715 let keys_id = Readable::read(reader)?;
717 Ok(InMemoryChannelKeys {
721 delayed_payment_base_key,
724 channel_value_satoshis,
725 holder_channel_pubkeys,
726 channel_parameters: counterparty_channel_data,
727 channel_keys_id: keys_id,
732 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
733 /// and derives keys from that.
735 /// Your node_id is seed/0'
736 /// ChannelMonitor closes may use seed/1'
737 /// Cooperative closes may use seed/2'
738 /// The two close keys may be needed to claim on-chain funds!
739 pub struct KeysManager {
740 secp_ctx: Secp256k1<secp256k1::SignOnly>,
741 node_secret: SecretKey,
742 destination_script: Script,
743 shutdown_pubkey: PublicKey,
744 channel_master_key: ExtendedPrivKey,
745 channel_child_index: AtomicUsize,
746 rand_bytes_master_key: ExtendedPrivKey,
747 rand_bytes_child_index: AtomicUsize,
750 starting_time_secs: u64,
751 starting_time_nanos: u32,
755 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
756 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
757 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
758 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
759 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
760 /// simply use the current time (with very high precision).
762 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
763 /// obviously, starting_time should be unique every time you reload the library - it is only
764 /// used to generate new ephemeral key data (which will be stored by the individual channel if
767 /// Note that the seed is required to recover certain on-chain funds independent of
768 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
769 /// channel, and some on-chain during-closing funds.
771 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
772 /// versions. Once the library is more fully supported, the docs will be updated to include a
773 /// detailed description of the guarantee.
774 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
775 let secp_ctx = Secp256k1::signing_only();
776 // Note that when we aren't serializing the key, network doesn't matter
777 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
779 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
780 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
781 Ok(destination_key) => {
782 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
783 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
784 .push_slice(&wpubkey_hash.into_inner())
787 Err(_) => panic!("Your RNG is busted"),
789 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
790 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
791 Err(_) => panic!("Your RNG is busted"),
793 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
794 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
802 channel_child_index: AtomicUsize::new(0),
803 rand_bytes_master_key,
804 rand_bytes_child_index: AtomicUsize::new(0),
811 Err(_) => panic!("Your rng is busted"),
814 fn derive_unique_start(&self) -> Sha256State {
815 let mut unique_start = Sha256::engine();
816 unique_start.input(&byte_utils::be64_to_array(self.starting_time_secs));
817 unique_start.input(&byte_utils::be32_to_array(self.starting_time_nanos));
818 unique_start.input(&self.seed);
821 /// Derive an old set of ChannelKeys for per-channel secrets based on a key derivation
823 /// Key derivation parameters are accessible through a per-channel secrets
824 /// ChannelKeys::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
825 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
826 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemoryChannelKeys {
827 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
828 assert!(chan_id <= std::u32::MAX as u64); // Otherwise the params field wasn't created by us
829 let mut unique_start = Sha256::engine();
830 unique_start.input(params);
831 unique_start.input(&self.seed);
833 // We only seriously intend to rely on the channel_master_key for true secure
834 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
835 // starting_time provided in the constructor) to be unique.
836 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");
837 unique_start.input(&child_privkey.private_key.key[..]);
839 let seed = Sha256::from_engine(unique_start).into_inner();
841 let commitment_seed = {
842 let mut sha = Sha256::engine();
844 sha.input(&b"commitment seed"[..]);
845 Sha256::from_engine(sha).into_inner()
847 macro_rules! key_step {
848 ($info: expr, $prev_key: expr) => {{
849 let mut sha = Sha256::engine();
851 sha.input(&$prev_key[..]);
852 sha.input(&$info[..]);
853 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
856 let funding_key = key_step!(b"funding key", commitment_seed);
857 let revocation_base_key = key_step!(b"revocation base key", funding_key);
858 let payment_key = key_step!(b"payment key", revocation_base_key);
859 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
860 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
862 InMemoryChannelKeys::new(
867 delayed_payment_base_key,
870 channel_value_satoshis,
875 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
876 /// output to the given change destination (if sufficient change value remains). The
877 /// transaction will have a feerate, at least, of the given value.
879 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
880 /// if a descriptor was duplicated.
882 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
884 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
885 /// this KeysManager or one of the `InMemoryChannelKeys` created by this KeysManager.
886 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, ()> {
887 let mut input = Vec::new();
888 let mut input_value = 0;
889 let mut witness_weight = 0;
890 let mut output_set = HashSet::with_capacity(descriptors.len());
891 for outp in descriptors {
893 SpendableOutputDescriptor::StaticOutputCounterpartyPayment(descriptor) => {
895 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
896 script_sig: Script::new(),
900 witness_weight += StaticCounterpartyPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
901 input_value += descriptor.output.value;
902 if !output_set.insert(descriptor.outpoint) { return Err(()); }
904 SpendableOutputDescriptor::DynamicOutputP2WSH(descriptor) => {
906 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
907 script_sig: Script::new(),
908 sequence: descriptor.to_self_delay as u32,
911 witness_weight += DynamicP2WSHOutputDescriptor::MAX_WITNESS_LENGTH;
912 input_value += descriptor.output.value;
913 if !output_set.insert(descriptor.outpoint) { return Err(()); }
915 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
917 previous_output: outpoint.into_bitcoin_outpoint(),
918 script_sig: Script::new(),
922 witness_weight += 1 + 73 + 34;
923 input_value += output.value;
924 if !output_set.insert(*outpoint) { return Err(()); }
927 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
929 let mut spend_tx = Transaction {
935 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
937 let mut keys_cache: Option<(InMemoryChannelKeys, [u8; 32])> = None;
938 let mut input_idx = 0;
939 for outp in descriptors {
941 SpendableOutputDescriptor::StaticOutputCounterpartyPayment(descriptor) => {
942 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
944 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
945 descriptor.channel_keys_id));
947 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
949 SpendableOutputDescriptor::DynamicOutputP2WSH(descriptor) => {
950 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
952 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
953 descriptor.channel_keys_id));
955 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
957 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
958 let derivation_idx = if output.script_pubkey == self.destination_script {
964 // Note that when we aren't serializing the key, network doesn't matter
965 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
967 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
969 Err(_) => panic!("Your RNG is busted"),
972 Err(_) => panic!("Your rng is busted"),
975 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
976 if derivation_idx == 2 {
977 assert_eq!(pubkey.key, self.shutdown_pubkey);
979 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
980 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
981 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
982 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
983 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
984 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
993 impl KeysInterface for KeysManager {
994 type ChanKeySigner = InMemoryChannelKeys;
996 fn get_node_secret(&self) -> SecretKey {
997 self.node_secret.clone()
1000 fn get_destination_script(&self) -> Script {
1001 self.destination_script.clone()
1004 fn get_shutdown_pubkey(&self) -> PublicKey {
1005 self.shutdown_pubkey.clone()
1008 fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner {
1009 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1010 assert!(child_ix <= std::u32::MAX as usize);
1011 let mut id = [0; 32];
1012 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1013 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1014 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1015 self.derive_channel_keys(channel_value_satoshis, &id)
1018 fn get_secure_random_bytes(&self) -> [u8; 32] {
1019 let mut sha = self.derive_unique_start();
1021 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1022 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");
1023 sha.input(&child_privkey.private_key.key[..]);
1025 sha.input(b"Unique Secure Random Bytes Salt");
1026 Sha256::from_engine(sha).into_inner()
1029 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError> {
1030 InMemoryChannelKeys::read(&mut std::io::Cursor::new(reader))