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::recovery::RecoverableSignature;
30 use bitcoin::secp256k1;
32 use util::{byte_utils, transaction_utils};
33 use util::ser::{Writeable, Writer, Readable};
35 use chain::transaction::OutPoint;
37 use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
38 use ln::msgs::UnsignedChannelAnnouncement;
41 use std::collections::HashSet;
42 use core::sync::atomic::{AtomicUsize, Ordering};
44 use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
46 /// Information about a spendable output to a P2WSH script. See
47 /// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
48 #[derive(Clone, Debug, PartialEq)]
49 pub struct DelayedPaymentOutputDescriptor {
50 /// The outpoint which is spendable
51 pub outpoint: OutPoint,
52 /// Per commitment point to derive delayed_payment_key by key holder
53 pub per_commitment_point: PublicKey,
54 /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
55 /// the witness_script.
56 pub to_self_delay: u16,
57 /// The output which is referenced by the given outpoint
59 /// The revocation point specific to the commitment transaction which was broadcast. Used to
60 /// derive the witnessScript for this output.
61 pub revocation_pubkey: PublicKey,
62 /// Arbitrary identification information returned by a call to
63 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
64 /// the channel to spend the output.
65 pub channel_keys_id: [u8; 32],
66 /// The value of the channel which this output originated from, possibly indirectly.
67 pub channel_value_satoshis: u64,
69 impl DelayedPaymentOutputDescriptor {
70 /// The maximum length a well-formed witness spending one of these should have.
71 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
72 // redeemscript push length.
73 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
76 /// Information about a spendable output to our "payment key". See
77 /// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
78 #[derive(Clone, Debug, PartialEq)]
79 pub struct StaticPaymentOutputDescriptor {
80 /// The outpoint which is spendable
81 pub outpoint: OutPoint,
82 /// The output which is referenced by the given outpoint
84 /// Arbitrary identification information returned by a call to
85 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
86 /// the channel to spend the output.
87 pub channel_keys_id: [u8; 32],
88 /// The value of the channel which this transactions spends.
89 pub channel_value_satoshis: u64,
91 impl StaticPaymentOutputDescriptor {
92 /// The maximum length a well-formed witness spending one of these should have.
93 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
94 // redeemscript push length.
95 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
98 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
99 /// claim at any point in the future) an event is generated which you must track and be able to
100 /// spend on-chain. The information needed to do this is provided in this enum, including the
101 /// outpoint describing which txid and output index is available, the full output which exists at
102 /// that txid/index, and any keys or other information required to sign.
103 #[derive(Clone, Debug, PartialEq)]
104 pub enum SpendableOutputDescriptor {
105 /// An output to a script which was provided via KeysInterface directly, either from
106 /// `get_destination_script()` or `get_shutdown_pubkey()`, thus you should already know how to
107 /// spend it. No secret keys are provided as rust-lightning was never given any key.
108 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
109 /// on-chain using the payment preimage or after it has timed out.
111 /// The outpoint which is spendable
113 /// The output which is referenced by the given outpoint.
116 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
118 /// The witness in the spending input should be:
119 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
121 /// Note that the nSequence field in the spending input must be set to to_self_delay
122 /// (which means the transaction is not broadcastable until at least to_self_delay
123 /// blocks after the outpoint confirms).
125 /// These are generally the result of a "revocable" output to us, spendable only by us unless
126 /// it is an output from an old state which we broadcast (which should never happen).
128 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
129 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
130 /// Sign::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
131 /// chan_utils::derive_private_key. The public key can be generated without the secret key
132 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
135 /// To derive the revocation_pubkey provided here (which is used in the witness
136 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
137 /// call to Sign::ready_channel) and the provided per_commitment point
138 /// to chan_utils::derive_public_revocation_key.
140 /// The witness script which is hashed and included in the output script_pubkey may be
141 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
142 /// (derived as above), and the to_self_delay contained here to
143 /// chan_utils::get_revokeable_redeemscript.
144 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
145 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
146 /// corresponds to the public key in Sign::pubkeys().payment_point).
147 /// The witness in the spending input, is, thus, simply:
148 /// <BIP 143 signature> <payment key>
150 /// These are generally the result of our counterparty having broadcast the current state,
151 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
152 StaticPaymentOutput(StaticPaymentOutputDescriptor),
155 impl Writeable for SpendableOutputDescriptor {
156 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
158 &SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
160 outpoint.write(writer)?;
161 output.write(writer)?;
163 &SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) => {
165 descriptor.outpoint.write(writer)?;
166 descriptor.per_commitment_point.write(writer)?;
167 descriptor.to_self_delay.write(writer)?;
168 descriptor.output.write(writer)?;
169 descriptor.revocation_pubkey.write(writer)?;
170 descriptor.channel_keys_id.write(writer)?;
171 descriptor.channel_value_satoshis.write(writer)?;
173 &SpendableOutputDescriptor::StaticPaymentOutput(ref descriptor) => {
175 descriptor.outpoint.write(writer)?;
176 descriptor.output.write(writer)?;
177 descriptor.channel_keys_id.write(writer)?;
178 descriptor.channel_value_satoshis.write(writer)?;
185 impl Readable for SpendableOutputDescriptor {
186 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
187 match Readable::read(reader)? {
188 0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
189 outpoint: Readable::read(reader)?,
190 output: Readable::read(reader)?,
192 1u8 => Ok(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
193 outpoint: Readable::read(reader)?,
194 per_commitment_point: Readable::read(reader)?,
195 to_self_delay: Readable::read(reader)?,
196 output: Readable::read(reader)?,
197 revocation_pubkey: Readable::read(reader)?,
198 channel_keys_id: Readable::read(reader)?,
199 channel_value_satoshis: Readable::read(reader)?,
201 2u8 => Ok(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
202 outpoint: Readable::read(reader)?,
203 output: Readable::read(reader)?,
204 channel_keys_id: Readable::read(reader)?,
205 channel_value_satoshis: Readable::read(reader)?,
207 _ => Err(DecodeError::InvalidValue),
212 /// A trait to sign lightning channel transactions as described in BOLT 3.
214 /// Signing services could be implemented on a hardware wallet. In this case,
215 /// the current Sign would be a front-end on top of a communication
216 /// channel connected to your secure device and lightning key material wouldn't
217 /// reside on a hot server. Nevertheless, a this deployment would still need
218 /// to trust the ChannelManager to avoid loss of funds as this latest component
219 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
221 /// A more secure iteration would be to use hashlock (or payment points) to pair
222 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
223 /// at the price of more state and computation on the hardware wallet side. In the future,
224 /// we are looking forward to design such interface.
226 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
227 /// to act, as liveness and breach reply correctness are always going to be hard requirements
228 /// of LN security model, orthogonal of key management issues.
229 // TODO: We should remove Clone by instead requesting a new Sign copy when we create
230 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
232 /// Gets the per-commitment point for a specific commitment number
234 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
235 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
236 /// Gets the commitment secret for a specific commitment number as part of the revocation process
238 /// An external signer implementation should error here if the commitment was already signed
239 /// and should refuse to sign it in the future.
241 /// May be called more than once for the same index.
243 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
244 // TODO: return a Result so we can signal a validation error
245 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
246 /// Gets the holder's channel public keys and basepoints
247 fn pubkeys(&self) -> &ChannelPublicKeys;
248 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
249 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
250 /// Sign object uniquely and lookup or re-derive its keys.
251 fn channel_keys_id(&self) -> [u8; 32];
253 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
255 /// Note that if signing fails or is rejected, the channel will be force-closed.
257 // TODO: Document the things someone using this interface should enforce before signing.
258 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
260 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
261 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
262 /// latest commitment_tx when we initiate a force-close.
263 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
264 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
266 /// This may be called multiple times for the same transaction.
268 /// An external signer implementation should check that the commitment has not been revoked.
270 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
272 // TODO: Document the things someone using this interface should enforce before signing.
273 // TODO: Key derivation failure should panic rather than Err
274 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
276 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
277 /// transactions which will be broadcasted later, after the channel has moved on to a newer
278 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
280 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
281 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
283 /// Create a signature for the given input in a transaction spending an HTLC transaction output
284 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
286 /// A justice transaction may claim multiple outputs at the same time if timelocks are
287 /// similar, but only a signature for the input at index `input` should be signed for here.
288 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
289 /// to an upcoming timelock expiration.
291 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
293 /// per_commitment_key is revocation secret which was provided by our counterparty when they
294 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
295 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
297 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
299 /// Create a signature for the given input in a transaction spending a commitment transaction
300 /// HTLC output when our counterparty broadcasts an old state.
302 /// A justice transaction may claim multiple outputs at the same time if timelocks are
303 /// similar, but only a signature for the input at index `input` should be signed for here.
304 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
305 /// to an upcoming timelock expiration.
307 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
309 /// per_commitment_key is revocation secret which was provided by our counterparty when they
310 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
311 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
314 /// htlc holds HTLC elements (hash, timelock), thus changing the format of the witness script
315 /// (which is committed to in the BIP 143 signatures).
316 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
318 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
319 /// transaction, either offered or received.
321 /// Such a transaction may claim multiples offered outputs at same time if we know the
322 /// preimage for each when we create it, but only the input at index `input` should be
323 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
324 /// needed with regards to an upcoming timelock expiration.
326 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
329 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
331 /// Per_commitment_point is the dynamic point corresponding to the channel state
332 /// detected onchain. It has been generated by our counterparty and is used to derive
333 /// channel state keys, which are then included in the witness script and committed to in the
334 /// BIP 143 signature.
335 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
337 /// Create a signature for a (proposed) closing transaction.
339 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
340 /// chosen to forgo their output as dust.
341 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
343 /// Signs a channel announcement message with our funding key, proving it comes from one
344 /// of the channel participants.
346 /// Note that if this fails or is rejected, the channel will not be publicly announced and
347 /// our counterparty may (though likely will not) close the channel on us for violating the
349 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
351 /// Set the counterparty static channel data, including basepoints,
352 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
353 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
354 /// they MUST NOT be allowed to change to different values once set.
356 /// channel_parameters.is_populated() MUST be true.
358 /// We bind holder_selected_contest_delay late here for API convenience.
360 /// Will be called before any signatures are applied.
361 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
364 /// A cloneable signer.
366 /// Although we require signers to be cloneable, it may be useful for developers to be able to use
367 /// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
368 /// which implies Sized, into this derived trait.
369 pub trait Sign: BaseSign + Writeable + Clone {
372 /// A trait to describe an object which can get user secrets and key material.
373 pub trait KeysInterface {
374 /// A type which implements Sign which will be returned by get_channel_signer.
377 /// Get node secret key (aka node_id or network_key).
379 /// This method must return the same value each time it is called.
380 fn get_node_secret(&self) -> SecretKey;
381 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
383 /// This method should return a different value each time it is called, to avoid linking
384 /// on-chain funds across channels as controlled to the same user.
385 fn get_destination_script(&self) -> Script;
386 /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
389 /// This method should return a different value each time it is called, to avoid linking
390 /// on-chain funds across channels as controlled to the same user.
391 fn get_shutdown_pubkey(&self) -> PublicKey;
392 /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
393 /// restarted with some stale data!
395 /// This method must return a different value each time it is called.
396 fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
397 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
398 /// onion packets and for temporary channel IDs. There is no requirement that these be
399 /// persisted anywhere, though they must be unique across restarts.
401 /// This method must return a different value each time it is called.
402 fn get_secure_random_bytes(&self) -> [u8; 32];
404 /// Reads a `Signer` for this `KeysInterface` from the given input stream.
405 /// This is only called during deserialization of other objects which contain
406 /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
407 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
408 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
409 /// you've read all of the provided bytes to ensure no corruption occurred.
410 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
412 /// Sign an invoice's preimage (note that this is the preimage of the invoice, not the HTLC's
413 /// preimage). By parameterizing by the preimage instead of the hash, we allow implementors of
414 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
415 /// blindly signing the hash.
416 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()>;
420 /// A simple implementation of Sign that just keeps the private keys in memory.
422 /// This implementation performs no policy checks and is insufficient by itself as
423 /// a secure external signer.
424 pub struct InMemorySigner {
425 /// Private key of anchor tx
426 pub funding_key: SecretKey,
427 /// Holder secret key for blinded revocation pubkey
428 pub revocation_base_key: SecretKey,
429 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
430 pub payment_key: SecretKey,
431 /// Holder secret key used in HTLC tx
432 pub delayed_payment_base_key: SecretKey,
433 /// Holder htlc secret key used in commitment tx htlc outputs
434 pub htlc_base_key: SecretKey,
436 pub commitment_seed: [u8; 32],
437 /// Holder public keys and basepoints
438 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
439 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
440 channel_parameters: Option<ChannelTransactionParameters>,
441 /// The total value of this channel
442 channel_value_satoshis: u64,
443 /// Key derivation parameters
444 channel_keys_id: [u8; 32],
447 impl InMemorySigner {
448 /// Create a new InMemorySigner
449 pub fn new<C: Signing>(
450 secp_ctx: &Secp256k1<C>,
451 funding_key: SecretKey,
452 revocation_base_key: SecretKey,
453 payment_key: SecretKey,
454 delayed_payment_base_key: SecretKey,
455 htlc_base_key: SecretKey,
456 commitment_seed: [u8; 32],
457 channel_value_satoshis: u64,
458 channel_keys_id: [u8; 32]) -> InMemorySigner {
459 let holder_channel_pubkeys =
460 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
461 &payment_key, &delayed_payment_base_key,
467 delayed_payment_base_key,
470 channel_value_satoshis,
471 holder_channel_pubkeys,
472 channel_parameters: None,
477 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
478 funding_key: &SecretKey,
479 revocation_base_key: &SecretKey,
480 payment_key: &SecretKey,
481 delayed_payment_base_key: &SecretKey,
482 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
483 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
485 funding_pubkey: from_secret(&funding_key),
486 revocation_basepoint: from_secret(&revocation_base_key),
487 payment_point: from_secret(&payment_key),
488 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
489 htlc_basepoint: from_secret(&htlc_base_key),
493 /// Counterparty pubkeys.
494 /// Will panic if ready_channel wasn't called.
495 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
497 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
498 /// transactions, ie the amount of time that we have to wait to recover our funds if we
499 /// broadcast a transaction.
500 /// Will panic if ready_channel wasn't called.
501 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
503 /// The contest_delay value specified by us and applied on transactions broadcastable
504 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
505 /// if they broadcast a transaction.
506 /// Will panic if ready_channel wasn't called.
507 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
509 /// Whether the holder is the initiator
510 /// Will panic if ready_channel wasn't called.
511 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
514 /// Will panic if ready_channel wasn't called.
515 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
517 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
518 /// building transactions.
520 /// Will panic if ready_channel wasn't called.
521 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
522 self.channel_parameters.as_ref().unwrap()
525 /// Sign the single input of spend_tx at index `input_idx` which spends the output
526 /// described by descriptor, returning the witness stack for the input.
528 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
529 /// or is not spending the outpoint described by `descriptor.outpoint`.
530 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
531 // TODO: We really should be taking the SigHashCache as a parameter here instead of
532 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
533 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
534 // bindings updates to support SigHashCache objects).
535 if spend_tx.input.len() <= input_idx { return Err(()); }
536 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
537 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
539 let remotepubkey = self.pubkeys().payment_point;
540 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
541 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
542 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
544 let mut witness = Vec::with_capacity(2);
545 witness.push(remotesig.serialize_der().to_vec());
546 witness[0].push(SigHashType::All as u8);
547 witness.push(remotepubkey.serialize().to_vec());
551 /// Sign the single input of spend_tx at index `input_idx` which spends the output
552 /// described by descriptor, returning the witness stack for the input.
554 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
555 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
556 /// sequence set to `descriptor.to_self_delay`.
557 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
558 // TODO: We really should be taking the SigHashCache as a parameter here instead of
559 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
560 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
561 // bindings updates to support SigHashCache objects).
562 if spend_tx.input.len() <= input_idx { return Err(()); }
563 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
564 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
565 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
567 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
568 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
569 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
570 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
571 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
572 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
574 let mut witness = Vec::with_capacity(3);
575 witness.push(local_delayedsig.serialize_der().to_vec());
576 witness[0].push(SigHashType::All as u8);
577 witness.push(vec!()); //MINIMALIF
578 witness.push(witness_script.clone().into_bytes());
583 impl BaseSign for InMemorySigner {
584 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
585 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
586 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
589 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
590 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
593 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
594 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
596 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
597 let trusted_tx = commitment_tx.trust();
598 let keys = trusted_tx.keys();
600 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
601 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
603 let built_tx = trusted_tx.built_transaction();
604 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
605 let commitment_txid = built_tx.txid;
607 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
608 for htlc in commitment_tx.htlcs() {
609 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);
610 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
611 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
612 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
613 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
616 Ok((commitment_sig, htlc_sigs))
619 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
620 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
621 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
622 let trusted_tx = commitment_tx.trust();
623 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
624 let channel_parameters = self.get_channel_parameters();
625 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
629 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
630 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
631 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
632 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
633 let trusted_tx = commitment_tx.trust();
634 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
635 let channel_parameters = self.get_channel_parameters();
636 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
640 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
641 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
642 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
643 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
644 let witness_script = {
645 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_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_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
654 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
655 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
656 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
657 let witness_script = {
658 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
659 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
660 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
662 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
663 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
664 return Ok(secp_ctx.sign(&sighash, &revocation_key))
667 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
668 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
669 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
670 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
671 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
672 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
673 } else { return Err(()) }
674 } else { return Err(()) }
675 } else { return Err(()) };
676 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
677 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
678 return Ok(secp_ctx.sign(&sighash, &htlc_key))
683 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
684 if closing_tx.input.len() != 1 { return Err(()); }
685 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
686 if closing_tx.output.len() > 2 { return Err(()); }
688 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
689 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
691 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
692 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
693 Ok(secp_ctx.sign(&sighash, &self.funding_key))
696 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
697 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
698 Ok(secp_ctx.sign(&msghash, &self.funding_key))
701 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
702 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
703 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
704 self.channel_parameters = Some(channel_parameters.clone());
708 const SERIALIZATION_VERSION: u8 = 1;
709 const MIN_SERIALIZATION_VERSION: u8 = 1;
711 impl Sign for InMemorySigner {}
713 impl Writeable for InMemorySigner {
714 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
715 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
717 self.funding_key.write(writer)?;
718 self.revocation_base_key.write(writer)?;
719 self.payment_key.write(writer)?;
720 self.delayed_payment_base_key.write(writer)?;
721 self.htlc_base_key.write(writer)?;
722 self.commitment_seed.write(writer)?;
723 self.channel_parameters.write(writer)?;
724 self.channel_value_satoshis.write(writer)?;
725 self.channel_keys_id.write(writer)?;
727 write_tlv_fields!(writer, {}, {});
733 impl Readable for InMemorySigner {
734 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
735 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
737 let funding_key = Readable::read(reader)?;
738 let revocation_base_key = Readable::read(reader)?;
739 let payment_key = Readable::read(reader)?;
740 let delayed_payment_base_key = Readable::read(reader)?;
741 let htlc_base_key = Readable::read(reader)?;
742 let commitment_seed = Readable::read(reader)?;
743 let counterparty_channel_data = Readable::read(reader)?;
744 let channel_value_satoshis = Readable::read(reader)?;
745 let secp_ctx = Secp256k1::signing_only();
746 let holder_channel_pubkeys =
747 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
748 &payment_key, &delayed_payment_base_key,
750 let keys_id = Readable::read(reader)?;
752 read_tlv_fields!(reader, {}, {});
758 delayed_payment_base_key,
761 channel_value_satoshis,
762 holder_channel_pubkeys,
763 channel_parameters: counterparty_channel_data,
764 channel_keys_id: keys_id,
769 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
770 /// and derives keys from that.
772 /// Your node_id is seed/0'
773 /// ChannelMonitor closes may use seed/1'
774 /// Cooperative closes may use seed/2'
775 /// The two close keys may be needed to claim on-chain funds!
776 pub struct KeysManager {
777 secp_ctx: Secp256k1<secp256k1::All>,
778 node_secret: SecretKey,
779 destination_script: Script,
780 shutdown_pubkey: PublicKey,
781 channel_master_key: ExtendedPrivKey,
782 channel_child_index: AtomicUsize,
784 rand_bytes_master_key: ExtendedPrivKey,
785 rand_bytes_child_index: AtomicUsize,
786 rand_bytes_unique_start: Sha256State,
789 starting_time_secs: u64,
790 starting_time_nanos: u32,
794 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
795 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
796 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
797 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
798 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
799 /// simply use the current time (with very high precision).
801 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
802 /// obviously, starting_time should be unique every time you reload the library - it is only
803 /// used to generate new ephemeral key data (which will be stored by the individual channel if
806 /// Note that the seed is required to recover certain on-chain funds independent of
807 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
808 /// channel, and some on-chain during-closing funds.
810 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
811 /// versions. Once the library is more fully supported, the docs will be updated to include a
812 /// detailed description of the guarantee.
813 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
814 let secp_ctx = Secp256k1::new();
815 // Note that when we aren't serializing the key, network doesn't matter
816 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
818 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
819 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
820 Ok(destination_key) => {
821 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
822 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
823 .push_slice(&wpubkey_hash.into_inner())
826 Err(_) => panic!("Your RNG is busted"),
828 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
829 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
830 Err(_) => panic!("Your RNG is busted"),
832 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
833 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
835 let mut rand_bytes_unique_start = Sha256::engine();
836 rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
837 rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
838 rand_bytes_unique_start.input(seed);
840 let mut res = KeysManager {
848 channel_child_index: AtomicUsize::new(0),
850 rand_bytes_master_key,
851 rand_bytes_child_index: AtomicUsize::new(0),
852 rand_bytes_unique_start,
858 let secp_seed = res.get_secure_random_bytes();
859 res.secp_ctx.seeded_randomize(&secp_seed);
862 Err(_) => panic!("Your rng is busted"),
865 /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
867 /// Key derivation parameters are accessible through a per-channel secrets
868 /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
869 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
870 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
871 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
872 assert!(chan_id <= core::u32::MAX as u64); // Otherwise the params field wasn't created by us
873 let mut unique_start = Sha256::engine();
874 unique_start.input(params);
875 unique_start.input(&self.seed);
877 // We only seriously intend to rely on the channel_master_key for true secure
878 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
879 // starting_time provided in the constructor) to be unique.
880 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");
881 unique_start.input(&child_privkey.private_key.key[..]);
883 let seed = Sha256::from_engine(unique_start).into_inner();
885 let commitment_seed = {
886 let mut sha = Sha256::engine();
888 sha.input(&b"commitment seed"[..]);
889 Sha256::from_engine(sha).into_inner()
891 macro_rules! key_step {
892 ($info: expr, $prev_key: expr) => {{
893 let mut sha = Sha256::engine();
895 sha.input(&$prev_key[..]);
896 sha.input(&$info[..]);
897 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
900 let funding_key = key_step!(b"funding key", commitment_seed);
901 let revocation_base_key = key_step!(b"revocation base key", funding_key);
902 let payment_key = key_step!(b"payment key", revocation_base_key);
903 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
904 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
911 delayed_payment_base_key,
914 channel_value_satoshis,
919 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
920 /// output to the given change destination (if sufficient change value remains). The
921 /// transaction will have a feerate, at least, of the given value.
923 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
924 /// if a descriptor was duplicated.
926 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
928 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
929 /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
930 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, ()> {
931 let mut input = Vec::new();
932 let mut input_value = 0;
933 let mut witness_weight = 0;
934 let mut output_set = HashSet::with_capacity(descriptors.len());
935 for outp in descriptors {
937 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
939 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
940 script_sig: Script::new(),
944 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
945 input_value += descriptor.output.value;
946 if !output_set.insert(descriptor.outpoint) { return Err(()); }
948 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
950 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
951 script_sig: Script::new(),
952 sequence: descriptor.to_self_delay as u32,
955 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
956 input_value += descriptor.output.value;
957 if !output_set.insert(descriptor.outpoint) { return Err(()); }
959 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
961 previous_output: outpoint.into_bitcoin_outpoint(),
962 script_sig: Script::new(),
966 witness_weight += 1 + 73 + 34;
967 input_value += output.value;
968 if !output_set.insert(*outpoint) { return Err(()); }
971 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
973 let mut spend_tx = Transaction {
979 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
981 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
982 let mut input_idx = 0;
983 for outp in descriptors {
985 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
986 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
988 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
989 descriptor.channel_keys_id));
991 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
993 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
994 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
996 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
997 descriptor.channel_keys_id));
999 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
1001 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
1002 let derivation_idx = if output.script_pubkey == self.destination_script {
1008 // Note that when we aren't serializing the key, network doesn't matter
1009 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1011 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1013 Err(_) => panic!("Your RNG is busted"),
1016 Err(_) => panic!("Your rng is busted"),
1019 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
1020 if derivation_idx == 2 {
1021 assert_eq!(pubkey.key, self.shutdown_pubkey);
1023 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1024 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
1025 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
1026 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
1027 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
1028 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1037 impl KeysInterface for KeysManager {
1038 type Signer = InMemorySigner;
1040 fn get_node_secret(&self) -> SecretKey {
1041 self.node_secret.clone()
1044 fn get_destination_script(&self) -> Script {
1045 self.destination_script.clone()
1048 fn get_shutdown_pubkey(&self) -> PublicKey {
1049 self.shutdown_pubkey.clone()
1052 fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
1053 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1054 assert!(child_ix <= core::u32::MAX as usize);
1055 let mut id = [0; 32];
1056 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1057 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1058 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1059 self.derive_channel_keys(channel_value_satoshis, &id)
1062 fn get_secure_random_bytes(&self) -> [u8; 32] {
1063 let mut sha = self.rand_bytes_unique_start.clone();
1065 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1066 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");
1067 sha.input(&child_privkey.private_key.key[..]);
1069 sha.input(b"Unique Secure Random Bytes Salt");
1070 Sha256::from_engine(sha).into_inner()
1073 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1074 InMemorySigner::read(&mut std::io::Cursor::new(reader))
1077 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
1078 Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
1082 // Ensure that BaseSign can have a vtable
1085 let _signer: Box<dyn BaseSign>;