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 core::sync::atomic::{AtomicUsize, Ordering};
43 use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
45 /// Information about a spendable output to a P2WSH script. See
46 /// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
47 #[derive(Clone, Debug, PartialEq)]
48 pub struct DelayedPaymentOutputDescriptor {
49 /// The outpoint which is spendable
50 pub outpoint: OutPoint,
51 /// Per commitment point to derive delayed_payment_key by key holder
52 pub per_commitment_point: PublicKey,
53 /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
54 /// the witness_script.
55 pub to_self_delay: u16,
56 /// The output which is referenced by the given outpoint
58 /// The revocation point specific to the commitment transaction which was broadcast. Used to
59 /// derive the witnessScript for this output.
60 pub revocation_pubkey: PublicKey,
61 /// Arbitrary identification information returned by a call to
62 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
63 /// the channel to spend the output.
64 pub channel_keys_id: [u8; 32],
65 /// The value of the channel which this output originated from, possibly indirectly.
66 pub channel_value_satoshis: u64,
68 impl DelayedPaymentOutputDescriptor {
69 /// The maximum length a well-formed witness spending one of these should have.
70 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
71 // redeemscript push length.
72 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
75 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
76 (0, outpoint, required),
77 (2, per_commitment_point, required),
78 (4, to_self_delay, required),
79 (6, output, required),
80 (8, revocation_pubkey, required),
81 (10, channel_keys_id, required),
82 (12, channel_value_satoshis, required),
85 /// Information about a spendable output to our "payment key". See
86 /// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
87 #[derive(Clone, Debug, PartialEq)]
88 pub struct StaticPaymentOutputDescriptor {
89 /// The outpoint which is spendable
90 pub outpoint: OutPoint,
91 /// The output which is referenced by the given outpoint
93 /// Arbitrary identification information returned by a call to
94 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
95 /// the channel to spend the output.
96 pub channel_keys_id: [u8; 32],
97 /// The value of the channel which this transactions spends.
98 pub channel_value_satoshis: u64,
100 impl StaticPaymentOutputDescriptor {
101 /// The maximum length a well-formed witness spending one of these should have.
102 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
103 // redeemscript push length.
104 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
106 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
107 (0, outpoint, required),
108 (2, output, required),
109 (4, channel_keys_id, required),
110 (6, channel_value_satoshis, required),
113 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
114 /// claim at any point in the future) an event is generated which you must track and be able to
115 /// spend on-chain. The information needed to do this is provided in this enum, including the
116 /// outpoint describing which txid and output index is available, the full output which exists at
117 /// that txid/index, and any keys or other information required to sign.
118 #[derive(Clone, Debug, PartialEq)]
119 pub enum SpendableOutputDescriptor {
120 /// An output to a script which was provided via KeysInterface directly, either from
121 /// `get_destination_script()` or `get_shutdown_pubkey()`, thus you should already know how to
122 /// spend it. No secret keys are provided as rust-lightning was never given any key.
123 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
124 /// on-chain using the payment preimage or after it has timed out.
126 /// The outpoint which is spendable
128 /// The output which is referenced by the given outpoint.
131 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
133 /// The witness in the spending input should be:
134 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
136 /// Note that the nSequence field in the spending input must be set to to_self_delay
137 /// (which means the transaction is not broadcastable until at least to_self_delay
138 /// blocks after the outpoint confirms).
140 /// These are generally the result of a "revocable" output to us, spendable only by us unless
141 /// it is an output from an old state which we broadcast (which should never happen).
143 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
144 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
145 /// Sign::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
146 /// chan_utils::derive_private_key. The public key can be generated without the secret key
147 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
150 /// To derive the revocation_pubkey provided here (which is used in the witness
151 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
152 /// call to Sign::ready_channel) and the provided per_commitment point
153 /// to chan_utils::derive_public_revocation_key.
155 /// The witness script which is hashed and included in the output script_pubkey may be
156 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
157 /// (derived as above), and the to_self_delay contained here to
158 /// chan_utils::get_revokeable_redeemscript.
159 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
160 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
161 /// corresponds to the public key in Sign::pubkeys().payment_point).
162 /// The witness in the spending input, is, thus, simply:
163 /// <BIP 143 signature> <payment key>
165 /// These are generally the result of our counterparty having broadcast the current state,
166 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
167 StaticPaymentOutput(StaticPaymentOutputDescriptor),
170 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
171 (0, StaticOutput) => {
172 (0, outpoint, required),
173 (2, output, required),
176 (1, DelayedPaymentOutput),
177 (2, StaticPaymentOutput),
180 /// A trait to sign lightning channel transactions as described in BOLT 3.
182 /// Signing services could be implemented on a hardware wallet. In this case,
183 /// the current Sign would be a front-end on top of a communication
184 /// channel connected to your secure device and lightning key material wouldn't
185 /// reside on a hot server. Nevertheless, a this deployment would still need
186 /// to trust the ChannelManager to avoid loss of funds as this latest component
187 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
189 /// A more secure iteration would be to use hashlock (or payment points) to pair
190 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
191 /// at the price of more state and computation on the hardware wallet side. In the future,
192 /// we are looking forward to design such interface.
194 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
195 /// to act, as liveness and breach reply correctness are always going to be hard requirements
196 /// of LN security model, orthogonal of key management issues.
197 // TODO: We should remove Clone by instead requesting a new Sign copy when we create
198 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
200 /// Gets the per-commitment point for a specific commitment number
202 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
203 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
204 /// Gets the commitment secret for a specific commitment number as part of the revocation process
206 /// An external signer implementation should error here if the commitment was already signed
207 /// and should refuse to sign it in the future.
209 /// May be called more than once for the same index.
211 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
212 // TODO: return a Result so we can signal a validation error
213 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
214 /// Gets the holder's channel public keys and basepoints
215 fn pubkeys(&self) -> &ChannelPublicKeys;
216 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
217 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
218 /// Sign object uniquely and lookup or re-derive its keys.
219 fn channel_keys_id(&self) -> [u8; 32];
221 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
223 /// Note that if signing fails or is rejected, the channel will be force-closed.
225 // TODO: Document the things someone using this interface should enforce before signing.
226 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
228 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
229 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
230 /// latest commitment_tx when we initiate a force-close.
231 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
232 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
234 /// This may be called multiple times for the same transaction.
236 /// An external signer implementation should check that the commitment has not been revoked.
238 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
240 // TODO: Document the things someone using this interface should enforce before signing.
241 // TODO: Key derivation failure should panic rather than Err
242 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
244 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
245 /// transactions which will be broadcasted later, after the channel has moved on to a newer
246 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
248 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
249 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
251 /// Create a signature for the given input in a transaction spending an HTLC transaction output
252 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
254 /// A justice transaction may claim multiple outputs at the same time if timelocks are
255 /// similar, but only a signature for the input at index `input` should be signed for here.
256 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
257 /// to an upcoming timelock expiration.
259 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
261 /// per_commitment_key is revocation secret which was provided by our counterparty when they
262 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
263 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
265 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
267 /// Create a signature for the given input in a transaction spending a commitment transaction
268 /// HTLC output when our counterparty broadcasts an old state.
270 /// A justice transaction may claim multiple outputs at the same time if timelocks are
271 /// similar, but only a signature for the input at index `input` should be signed for here.
272 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
273 /// to an upcoming timelock expiration.
275 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
277 /// per_commitment_key is revocation secret which was provided by our counterparty when they
278 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
279 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
282 /// htlc holds HTLC elements (hash, timelock), thus changing the format of the witness script
283 /// (which is committed to in the BIP 143 signatures).
284 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, ()>;
286 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
287 /// transaction, either offered or received.
289 /// Such a transaction may claim multiples offered outputs at same time if we know the
290 /// preimage for each when we create it, but only the input at index `input` should be
291 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
292 /// needed with regards to an upcoming timelock expiration.
294 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
297 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
299 /// Per_commitment_point is the dynamic point corresponding to the channel state
300 /// detected onchain. It has been generated by our counterparty and is used to derive
301 /// channel state keys, which are then included in the witness script and committed to in the
302 /// BIP 143 signature.
303 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, ()>;
305 /// Create a signature for a (proposed) closing transaction.
307 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
308 /// chosen to forgo their output as dust.
309 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
311 /// Signs a channel announcement message with our funding key, proving it comes from one
312 /// of the channel participants.
314 /// Note that if this fails or is rejected, the channel will not be publicly announced and
315 /// our counterparty may (though likely will not) close the channel on us for violating the
317 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
319 /// Set the counterparty static channel data, including basepoints,
320 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
321 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
322 /// they MUST NOT be allowed to change to different values once set.
324 /// channel_parameters.is_populated() MUST be true.
326 /// We bind holder_selected_contest_delay late here for API convenience.
328 /// Will be called before any signatures are applied.
329 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
332 /// A cloneable signer.
334 /// Although we require signers to be cloneable, it may be useful for developers to be able to use
335 /// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
336 /// which implies Sized, into this derived trait.
337 pub trait Sign: BaseSign + Writeable + Clone {
340 /// A trait to describe an object which can get user secrets and key material.
341 pub trait KeysInterface {
342 /// A type which implements Sign which will be returned by get_channel_signer.
345 /// Get node secret key (aka node_id or network_key).
347 /// This method must return the same value each time it is called.
348 fn get_node_secret(&self) -> SecretKey;
349 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
351 /// This method should return a different value each time it is called, to avoid linking
352 /// on-chain funds across channels as controlled to the same user.
353 fn get_destination_script(&self) -> Script;
354 /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
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_shutdown_pubkey(&self) -> PublicKey;
360 /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
361 /// restarted with some stale data!
363 /// This method must return a different value each time it is called.
364 fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
365 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
366 /// onion packets and for temporary channel IDs. There is no requirement that these be
367 /// persisted anywhere, though they must be unique across restarts.
369 /// This method must return a different value each time it is called.
370 fn get_secure_random_bytes(&self) -> [u8; 32];
372 /// Reads a `Signer` for this `KeysInterface` from the given input stream.
373 /// This is only called during deserialization of other objects which contain
374 /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
375 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
376 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
377 /// you've read all of the provided bytes to ensure no corruption occurred.
378 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
380 /// Sign an invoice's preimage (note that this is the preimage of the invoice, not the HTLC's
381 /// preimage). By parameterizing by the preimage instead of the hash, we allow implementors of
382 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
383 /// blindly signing the hash.
384 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()>;
388 /// A simple implementation of Sign 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 InMemorySigner {
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 InMemorySigner {
416 /// Create a new InMemorySigner
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]) -> InMemorySigner {
427 let holder_channel_pubkeys =
428 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
429 &payment_key, &delayed_payment_base_key,
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: &StaticPaymentOutputDescriptor, 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: &DelayedPaymentOutputDescriptor, 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 BaseSign for InMemorySigner {
552 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> 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(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> 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 = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
581 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
584 Ok((commitment_sig, htlc_sigs))
587 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
588 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
589 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
590 let trusted_tx = commitment_tx.trust();
591 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
592 let channel_parameters = self.get_channel_parameters();
593 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
597 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
598 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
599 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
600 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
601 let trusted_tx = commitment_tx.trust();
602 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
603 let channel_parameters = self.get_channel_parameters();
604 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
608 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
609 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
610 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
611 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
612 let witness_script = {
613 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_err(|_| ())?;
614 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
616 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
617 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
618 return Ok(secp_ctx.sign(&sighash, &revocation_key))
621 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, ()> {
622 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
623 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
624 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
625 let witness_script = {
626 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
627 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
628 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
630 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
631 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
632 return Ok(secp_ctx.sign(&sighash, &revocation_key))
635 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, ()> {
636 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
637 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
638 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
639 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
640 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
641 } else { return Err(()) }
642 } else { return Err(()) }
643 } else { return Err(()) };
644 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
645 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
646 return Ok(secp_ctx.sign(&sighash, &htlc_key))
651 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
652 if closing_tx.input.len() != 1 { return Err(()); }
653 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
654 if closing_tx.output.len() > 2 { return Err(()); }
656 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
657 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
659 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
660 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
661 Ok(secp_ctx.sign(&sighash, &self.funding_key))
664 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
665 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
666 Ok(secp_ctx.sign(&msghash, &self.funding_key))
669 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
670 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
671 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
672 self.channel_parameters = Some(channel_parameters.clone());
676 const SERIALIZATION_VERSION: u8 = 1;
677 const MIN_SERIALIZATION_VERSION: u8 = 1;
679 impl Sign for InMemorySigner {}
681 impl Writeable for InMemorySigner {
682 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
683 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
685 self.funding_key.write(writer)?;
686 self.revocation_base_key.write(writer)?;
687 self.payment_key.write(writer)?;
688 self.delayed_payment_base_key.write(writer)?;
689 self.htlc_base_key.write(writer)?;
690 self.commitment_seed.write(writer)?;
691 self.channel_parameters.write(writer)?;
692 self.channel_value_satoshis.write(writer)?;
693 self.channel_keys_id.write(writer)?;
695 write_tlv_fields!(writer, {});
701 impl Readable for InMemorySigner {
702 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
703 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
705 let funding_key = Readable::read(reader)?;
706 let revocation_base_key = Readable::read(reader)?;
707 let payment_key = Readable::read(reader)?;
708 let delayed_payment_base_key = Readable::read(reader)?;
709 let htlc_base_key = Readable::read(reader)?;
710 let commitment_seed = Readable::read(reader)?;
711 let counterparty_channel_data = Readable::read(reader)?;
712 let channel_value_satoshis = Readable::read(reader)?;
713 let secp_ctx = Secp256k1::signing_only();
714 let holder_channel_pubkeys =
715 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
716 &payment_key, &delayed_payment_base_key,
718 let keys_id = Readable::read(reader)?;
720 read_tlv_fields!(reader, {});
726 delayed_payment_base_key,
729 channel_value_satoshis,
730 holder_channel_pubkeys,
731 channel_parameters: counterparty_channel_data,
732 channel_keys_id: keys_id,
737 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
738 /// and derives keys from that.
740 /// Your node_id is seed/0'
741 /// ChannelMonitor closes may use seed/1'
742 /// Cooperative closes may use seed/2'
743 /// The two close keys may be needed to claim on-chain funds!
744 pub struct KeysManager {
745 secp_ctx: Secp256k1<secp256k1::All>,
746 node_secret: SecretKey,
747 destination_script: Script,
748 shutdown_pubkey: PublicKey,
749 channel_master_key: ExtendedPrivKey,
750 channel_child_index: AtomicUsize,
752 rand_bytes_master_key: ExtendedPrivKey,
753 rand_bytes_child_index: AtomicUsize,
754 rand_bytes_unique_start: Sha256State,
757 starting_time_secs: u64,
758 starting_time_nanos: u32,
762 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
763 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
764 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
765 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
766 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
767 /// simply use the current time (with very high precision).
769 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
770 /// obviously, starting_time should be unique every time you reload the library - it is only
771 /// used to generate new ephemeral key data (which will be stored by the individual channel if
774 /// Note that the seed is required to recover certain on-chain funds independent of
775 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
776 /// channel, and some on-chain during-closing funds.
778 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
779 /// versions. Once the library is more fully supported, the docs will be updated to include a
780 /// detailed description of the guarantee.
781 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
782 let secp_ctx = Secp256k1::new();
783 // Note that when we aren't serializing the key, network doesn't matter
784 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
786 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
787 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
788 Ok(destination_key) => {
789 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
790 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
791 .push_slice(&wpubkey_hash.into_inner())
794 Err(_) => panic!("Your RNG is busted"),
796 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
797 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
798 Err(_) => panic!("Your RNG is busted"),
800 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
801 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
803 let mut rand_bytes_unique_start = Sha256::engine();
804 rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
805 rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
806 rand_bytes_unique_start.input(seed);
808 let mut res = KeysManager {
816 channel_child_index: AtomicUsize::new(0),
818 rand_bytes_master_key,
819 rand_bytes_child_index: AtomicUsize::new(0),
820 rand_bytes_unique_start,
826 let secp_seed = res.get_secure_random_bytes();
827 res.secp_ctx.seeded_randomize(&secp_seed);
830 Err(_) => panic!("Your rng is busted"),
833 /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
835 /// Key derivation parameters are accessible through a per-channel secrets
836 /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
837 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
838 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
839 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
840 assert!(chan_id <= core::u32::MAX as u64); // Otherwise the params field wasn't created by us
841 let mut unique_start = Sha256::engine();
842 unique_start.input(params);
843 unique_start.input(&self.seed);
845 // We only seriously intend to rely on the channel_master_key for true secure
846 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
847 // starting_time provided in the constructor) to be unique.
848 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");
849 unique_start.input(&child_privkey.private_key.key[..]);
851 let seed = Sha256::from_engine(unique_start).into_inner();
853 let commitment_seed = {
854 let mut sha = Sha256::engine();
856 sha.input(&b"commitment seed"[..]);
857 Sha256::from_engine(sha).into_inner()
859 macro_rules! key_step {
860 ($info: expr, $prev_key: expr) => {{
861 let mut sha = Sha256::engine();
863 sha.input(&$prev_key[..]);
864 sha.input(&$info[..]);
865 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
868 let funding_key = key_step!(b"funding key", commitment_seed);
869 let revocation_base_key = key_step!(b"revocation base key", funding_key);
870 let payment_key = key_step!(b"payment key", revocation_base_key);
871 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
872 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
879 delayed_payment_base_key,
882 channel_value_satoshis,
887 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
888 /// output to the given change destination (if sufficient change value remains). The
889 /// transaction will have a feerate, at least, of the given value.
891 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
892 /// if a descriptor was duplicated.
894 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
896 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
897 /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
898 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, ()> {
899 let mut input = Vec::new();
900 let mut input_value = 0;
901 let mut witness_weight = 0;
902 let mut output_set = HashSet::with_capacity(descriptors.len());
903 for outp in descriptors {
905 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
907 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
908 script_sig: Script::new(),
912 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
913 input_value += descriptor.output.value;
914 if !output_set.insert(descriptor.outpoint) { return Err(()); }
916 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
918 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
919 script_sig: Script::new(),
920 sequence: descriptor.to_self_delay as u32,
923 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
924 input_value += descriptor.output.value;
925 if !output_set.insert(descriptor.outpoint) { return Err(()); }
927 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
929 previous_output: outpoint.into_bitcoin_outpoint(),
930 script_sig: Script::new(),
934 witness_weight += 1 + 73 + 34;
935 input_value += output.value;
936 if !output_set.insert(*outpoint) { return Err(()); }
939 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
941 let mut spend_tx = Transaction {
947 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
949 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
950 let mut input_idx = 0;
951 for outp in descriptors {
953 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
954 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
956 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
957 descriptor.channel_keys_id));
959 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
961 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
962 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
964 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
965 descriptor.channel_keys_id));
967 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
969 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
970 let derivation_idx = if output.script_pubkey == self.destination_script {
976 // Note that when we aren't serializing the key, network doesn't matter
977 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
979 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
981 Err(_) => panic!("Your RNG is busted"),
984 Err(_) => panic!("Your rng is busted"),
987 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
988 if derivation_idx == 2 {
989 assert_eq!(pubkey.key, self.shutdown_pubkey);
991 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
992 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
993 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
994 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
995 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
996 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1005 impl KeysInterface for KeysManager {
1006 type Signer = InMemorySigner;
1008 fn get_node_secret(&self) -> SecretKey {
1009 self.node_secret.clone()
1012 fn get_destination_script(&self) -> Script {
1013 self.destination_script.clone()
1016 fn get_shutdown_pubkey(&self) -> PublicKey {
1017 self.shutdown_pubkey.clone()
1020 fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
1021 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1022 assert!(child_ix <= core::u32::MAX as usize);
1023 let mut id = [0; 32];
1024 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1025 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1026 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1027 self.derive_channel_keys(channel_value_satoshis, &id)
1030 fn get_secure_random_bytes(&self) -> [u8; 32] {
1031 let mut sha = self.rand_bytes_unique_start.clone();
1033 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1034 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");
1035 sha.input(&child_privkey.private_key.key[..]);
1037 sha.input(b"Unique Secure Random Bytes Salt");
1038 Sha256::from_engine(sha).into_inner()
1041 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1042 InMemorySigner::read(&mut std::io::Cursor::new(reader))
1045 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
1046 Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
1050 // Ensure that BaseSign can have a vtable
1053 let _signer: Box<dyn BaseSign>;