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;
39 use ln::script::ShutdownScript;
42 use core::sync::atomic::{AtomicUsize, Ordering};
43 use io::{self, Error};
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 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
77 (0, outpoint, required),
78 (2, per_commitment_point, required),
79 (4, to_self_delay, required),
80 (6, output, required),
81 (8, revocation_pubkey, required),
82 (10, channel_keys_id, required),
83 (12, channel_value_satoshis, required),
86 /// Information about a spendable output to our "payment key". See
87 /// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
88 #[derive(Clone, Debug, PartialEq)]
89 pub struct StaticPaymentOutputDescriptor {
90 /// The outpoint which is spendable
91 pub outpoint: OutPoint,
92 /// The output which is referenced by the given outpoint
94 /// Arbitrary identification information returned by a call to
95 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
96 /// the channel to spend the output.
97 pub channel_keys_id: [u8; 32],
98 /// The value of the channel which this transactions spends.
99 pub channel_value_satoshis: u64,
101 impl StaticPaymentOutputDescriptor {
102 /// The maximum length a well-formed witness spending one of these should have.
103 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
104 // redeemscript push length.
105 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
107 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
108 (0, outpoint, required),
109 (2, output, required),
110 (4, channel_keys_id, required),
111 (6, channel_value_satoshis, required),
114 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
115 /// claim at any point in the future) an event is generated which you must track and be able to
116 /// spend on-chain. The information needed to do this is provided in this enum, including the
117 /// outpoint describing which txid and output index is available, the full output which exists at
118 /// that txid/index, and any keys or other information required to sign.
119 #[derive(Clone, Debug, PartialEq)]
120 pub enum SpendableOutputDescriptor {
121 /// An output to a script which was provided via KeysInterface directly, either from
122 /// `get_destination_script()` or `get_shutdown_scriptpubkey()`, thus you should already know
123 /// how to spend it. No secret keys are provided as rust-lightning was never given any key.
124 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
125 /// on-chain using the payment preimage or after it has timed out.
127 /// The outpoint which is spendable
129 /// The output which is referenced by the given outpoint.
132 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
134 /// The witness in the spending input should be:
135 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
137 /// Note that the nSequence field in the spending input must be set to to_self_delay
138 /// (which means the transaction is not broadcastable until at least to_self_delay
139 /// blocks after the outpoint confirms).
141 /// These are generally the result of a "revocable" output to us, spendable only by us unless
142 /// it is an output from an old state which we broadcast (which should never happen).
144 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
145 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
146 /// Sign::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
147 /// chan_utils::derive_private_key. The public key can be generated without the secret key
148 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
151 /// To derive the revocation_pubkey provided here (which is used in the witness
152 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
153 /// call to Sign::ready_channel) and the provided per_commitment point
154 /// to chan_utils::derive_public_revocation_key.
156 /// The witness script which is hashed and included in the output script_pubkey may be
157 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
158 /// (derived as above), and the to_self_delay contained here to
159 /// chan_utils::get_revokeable_redeemscript.
160 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
161 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
162 /// corresponds to the public key in Sign::pubkeys().payment_point).
163 /// The witness in the spending input, is, thus, simply:
164 /// <BIP 143 signature> <payment key>
166 /// These are generally the result of our counterparty having broadcast the current state,
167 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
168 StaticPaymentOutput(StaticPaymentOutputDescriptor),
171 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
172 (0, StaticOutput) => {
173 (0, outpoint, required),
174 (2, output, required),
177 (1, DelayedPaymentOutput),
178 (2, StaticPaymentOutput),
181 /// A trait to sign lightning channel transactions as described in BOLT 3.
183 /// Signing services could be implemented on a hardware wallet. In this case,
184 /// the current Sign would be a front-end on top of a communication
185 /// channel connected to your secure device and lightning key material wouldn't
186 /// reside on a hot server. Nevertheless, a this deployment would still need
187 /// to trust the ChannelManager to avoid loss of funds as this latest component
188 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
190 /// A more secure iteration would be to use hashlock (or payment points) to pair
191 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
192 /// at the price of more state and computation on the hardware wallet side. In the future,
193 /// we are looking forward to design such interface.
195 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
196 /// to act, as liveness and breach reply correctness are always going to be hard requirements
197 /// of LN security model, orthogonal of key management issues.
198 // TODO: We should remove Clone by instead requesting a new Sign copy when we create
199 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
201 /// Gets the per-commitment point for a specific commitment number
203 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
204 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
205 /// Gets the commitment secret for a specific commitment number as part of the revocation process
207 /// An external signer implementation should error here if the commitment was already signed
208 /// and should refuse to sign it in the future.
210 /// May be called more than once for the same index.
212 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
213 // TODO: return a Result so we can signal a validation error
214 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
215 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
217 /// This is required in order for the signer to make sure that releasing a commitment
218 /// secret won't leave us without a broadcastable holder transaction.
219 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction);
220 /// Gets the holder's channel public keys and basepoints
221 fn pubkeys(&self) -> &ChannelPublicKeys;
222 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
223 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
224 /// Sign object uniquely and lookup or re-derive its keys.
225 fn channel_keys_id(&self) -> [u8; 32];
227 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
229 /// Note that if signing fails or is rejected, the channel will be force-closed.
231 // TODO: Document the things someone using this interface should enforce before signing.
232 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
233 /// Validate the counterparty's revocation.
235 /// This is required in order for the signer to make sure that the state has moved
236 /// forward and it is safe to sign the next counterparty commitment.
237 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey);
239 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
240 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
241 /// latest commitment_tx when we initiate a force-close.
242 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
243 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
245 /// This may be called multiple times for the same transaction.
247 /// An external signer implementation should check that the commitment has not been revoked.
249 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
251 // TODO: Document the things someone using this interface should enforce before signing.
252 // TODO: Key derivation failure should panic rather than Err
253 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
255 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
256 /// transactions which will be broadcasted later, after the channel has moved on to a newer
257 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
259 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
260 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
262 /// Create a signature for the given input in a transaction spending an HTLC transaction output
263 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
265 /// A justice transaction may claim multiple outputs at the same time if timelocks are
266 /// similar, but only a signature for the input at index `input` should be signed for here.
267 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
268 /// to an upcoming timelock expiration.
270 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
272 /// per_commitment_key is revocation secret which was provided by our counterparty when they
273 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
274 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
276 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
278 /// Create a signature for the given input in a transaction spending a commitment transaction
279 /// HTLC output when our counterparty broadcasts an old state.
281 /// A justice transaction may claim multiple outputs at the same time if timelocks are
282 /// similar, but only a signature for the input at index `input` should be signed for here.
283 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
284 /// to an upcoming timelock expiration.
286 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
288 /// per_commitment_key is revocation secret which was provided by our counterparty when they
289 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
290 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
293 /// htlc holds HTLC elements (hash, timelock), thus changing the format of the witness script
294 /// (which is committed to in the BIP 143 signatures).
295 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, ()>;
297 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
298 /// transaction, either offered or received.
300 /// Such a transaction may claim multiples offered outputs at same time if we know the
301 /// preimage for each when we create it, but only the input at index `input` should be
302 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
303 /// needed with regards to an upcoming timelock expiration.
305 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
308 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
310 /// Per_commitment_point is the dynamic point corresponding to the channel state
311 /// detected onchain. It has been generated by our counterparty and is used to derive
312 /// channel state keys, which are then included in the witness script and committed to in the
313 /// BIP 143 signature.
314 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, ()>;
316 /// Create a signature for a (proposed) closing transaction.
318 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
319 /// chosen to forgo their output as dust.
320 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
322 /// Signs a channel announcement message with our funding key, proving it comes from one
323 /// of the channel participants.
325 /// Note that if this fails or is rejected, the channel will not be publicly announced and
326 /// our counterparty may (though likely will not) close the channel on us for violating the
328 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
330 /// Set the counterparty static channel data, including basepoints,
331 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
332 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
333 /// they MUST NOT be allowed to change to different values once set.
335 /// channel_parameters.is_populated() MUST be true.
337 /// We bind holder_selected_contest_delay late here for API convenience.
339 /// Will be called before any signatures are applied.
340 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
343 /// A cloneable signer.
345 /// Although we require signers to be cloneable, it may be useful for developers to be able to use
346 /// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
347 /// which implies Sized, into this derived trait.
348 pub trait Sign: BaseSign + Writeable + Clone {
351 /// A trait to describe an object which can get user secrets and key material.
352 pub trait KeysInterface {
353 /// A type which implements Sign which will be returned by get_channel_signer.
356 /// Get node secret key (aka node_id or network_key).
358 /// This method must return the same value each time it is called.
359 fn get_node_secret(&self) -> SecretKey;
360 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
362 /// This method should return a different value each time it is called, to avoid linking
363 /// on-chain funds across channels as controlled to the same user.
364 fn get_destination_script(&self) -> Script;
365 /// Get a script pubkey which we will send funds to when closing a channel.
367 /// This method should return a different value each time it is called, to avoid linking
368 /// on-chain funds across channels as controlled to the same user.
369 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
370 /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
371 /// restarted with some stale data!
373 /// This method must return a different value each time it is called.
374 fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
375 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
376 /// onion packets and for temporary channel IDs. There is no requirement that these be
377 /// persisted anywhere, though they must be unique across restarts.
379 /// This method must return a different value each time it is called.
380 fn get_secure_random_bytes(&self) -> [u8; 32];
382 /// Reads a `Signer` for this `KeysInterface` from the given input stream.
383 /// This is only called during deserialization of other objects which contain
384 /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
385 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
386 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
387 /// you've read all of the provided bytes to ensure no corruption occurred.
388 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
390 /// Sign an invoice's preimage (note that this is the preimage of the invoice, not the HTLC's
391 /// preimage). By parameterizing by the preimage instead of the hash, we allow implementors of
392 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
393 /// blindly signing the hash.
394 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()>;
398 /// A simple implementation of Sign that just keeps the private keys in memory.
400 /// This implementation performs no policy checks and is insufficient by itself as
401 /// a secure external signer.
402 pub struct InMemorySigner {
403 /// Private key of anchor tx
404 pub funding_key: SecretKey,
405 /// Holder secret key for blinded revocation pubkey
406 pub revocation_base_key: SecretKey,
407 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
408 pub payment_key: SecretKey,
409 /// Holder secret key used in HTLC tx
410 pub delayed_payment_base_key: SecretKey,
411 /// Holder htlc secret key used in commitment tx htlc outputs
412 pub htlc_base_key: SecretKey,
414 pub commitment_seed: [u8; 32],
415 /// Holder public keys and basepoints
416 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
417 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
418 channel_parameters: Option<ChannelTransactionParameters>,
419 /// The total value of this channel
420 channel_value_satoshis: u64,
421 /// Key derivation parameters
422 channel_keys_id: [u8; 32],
425 impl InMemorySigner {
426 /// Create a new InMemorySigner
427 pub fn new<C: Signing>(
428 secp_ctx: &Secp256k1<C>,
429 funding_key: SecretKey,
430 revocation_base_key: SecretKey,
431 payment_key: SecretKey,
432 delayed_payment_base_key: SecretKey,
433 htlc_base_key: SecretKey,
434 commitment_seed: [u8; 32],
435 channel_value_satoshis: u64,
436 channel_keys_id: [u8; 32]) -> InMemorySigner {
437 let holder_channel_pubkeys =
438 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
439 &payment_key, &delayed_payment_base_key,
445 delayed_payment_base_key,
448 channel_value_satoshis,
449 holder_channel_pubkeys,
450 channel_parameters: None,
455 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
456 funding_key: &SecretKey,
457 revocation_base_key: &SecretKey,
458 payment_key: &SecretKey,
459 delayed_payment_base_key: &SecretKey,
460 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
461 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
463 funding_pubkey: from_secret(&funding_key),
464 revocation_basepoint: from_secret(&revocation_base_key),
465 payment_point: from_secret(&payment_key),
466 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
467 htlc_basepoint: from_secret(&htlc_base_key),
471 /// Counterparty pubkeys.
472 /// Will panic if ready_channel wasn't called.
473 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
475 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
476 /// transactions, ie the amount of time that we have to wait to recover our funds if we
477 /// broadcast a transaction.
478 /// Will panic if ready_channel wasn't called.
479 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
481 /// The contest_delay value specified by us and applied on transactions broadcastable
482 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
483 /// if they broadcast a transaction.
484 /// Will panic if ready_channel wasn't called.
485 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
487 /// Whether the holder is the initiator
488 /// Will panic if ready_channel wasn't called.
489 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
492 /// Will panic if ready_channel wasn't called.
493 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
495 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
496 /// building transactions.
498 /// Will panic if ready_channel wasn't called.
499 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
500 self.channel_parameters.as_ref().unwrap()
503 /// Sign the single input of spend_tx at index `input_idx` which spends the output
504 /// described by descriptor, returning the witness stack for the input.
506 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
507 /// or is not spending the outpoint described by `descriptor.outpoint`.
508 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
509 // TODO: We really should be taking the SigHashCache as a parameter here instead of
510 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
511 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
512 // bindings updates to support SigHashCache objects).
513 if spend_tx.input.len() <= input_idx { return Err(()); }
514 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
515 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
517 let remotepubkey = self.pubkeys().payment_point;
518 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
519 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
520 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
522 let mut witness = Vec::with_capacity(2);
523 witness.push(remotesig.serialize_der().to_vec());
524 witness[0].push(SigHashType::All as u8);
525 witness.push(remotepubkey.serialize().to_vec());
529 /// Sign the single input of spend_tx at index `input_idx` which spends the output
530 /// described by descriptor, returning the witness stack for the input.
532 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
533 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
534 /// sequence set to `descriptor.to_self_delay`.
535 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
536 // TODO: We really should be taking the SigHashCache as a parameter here instead of
537 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
538 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
539 // bindings updates to support SigHashCache objects).
540 if spend_tx.input.len() <= input_idx { return Err(()); }
541 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
542 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
543 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
545 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
546 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
547 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
548 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
549 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
550 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
552 let mut witness = Vec::with_capacity(3);
553 witness.push(local_delayedsig.serialize_der().to_vec());
554 witness[0].push(SigHashType::All as u8);
555 witness.push(vec!()); //MINIMALIF
556 witness.push(witness_script.clone().into_bytes());
561 impl BaseSign for InMemorySigner {
562 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
563 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
564 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
567 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
568 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
571 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction) {
574 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
575 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
577 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
578 let trusted_tx = commitment_tx.trust();
579 let keys = trusted_tx.keys();
581 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
582 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
584 let built_tx = trusted_tx.built_transaction();
585 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
586 let commitment_txid = built_tx.txid;
588 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
589 for htlc in commitment_tx.htlcs() {
590 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);
591 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
592 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
593 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
594 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
597 Ok((commitment_sig, htlc_sigs))
600 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) {
603 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
604 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
605 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
606 let trusted_tx = commitment_tx.trust();
607 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
608 let channel_parameters = self.get_channel_parameters();
609 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
613 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
614 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
615 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
616 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
617 let trusted_tx = commitment_tx.trust();
618 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
619 let channel_parameters = self.get_channel_parameters();
620 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
624 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
625 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
626 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
627 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
628 let witness_script = {
629 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_err(|_| ())?;
630 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
632 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
633 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
634 return Ok(secp_ctx.sign(&sighash, &revocation_key))
637 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, ()> {
638 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
639 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
640 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
641 let witness_script = {
642 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
643 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
644 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
646 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
647 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
648 return Ok(secp_ctx.sign(&sighash, &revocation_key))
651 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, ()> {
652 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
653 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
654 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
655 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
656 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
657 } else { return Err(()) }
658 } else { return Err(()) }
659 } else { return Err(()) };
660 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
661 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
662 return Ok(secp_ctx.sign(&sighash, &htlc_key))
667 fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
668 if closing_tx.input.len() != 1 { return Err(()); }
669 if closing_tx.input[0].witness.len() != 0 { return Err(()); }
670 if closing_tx.output.len() > 2 { return Err(()); }
672 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
673 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
675 let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
676 .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
677 Ok(secp_ctx.sign(&sighash, &self.funding_key))
680 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
681 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
682 Ok(secp_ctx.sign(&msghash, &self.funding_key))
685 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
686 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
687 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
688 self.channel_parameters = Some(channel_parameters.clone());
692 const SERIALIZATION_VERSION: u8 = 1;
693 const MIN_SERIALIZATION_VERSION: u8 = 1;
695 impl Sign for InMemorySigner {}
697 impl Writeable for InMemorySigner {
698 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
699 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
701 self.funding_key.write(writer)?;
702 self.revocation_base_key.write(writer)?;
703 self.payment_key.write(writer)?;
704 self.delayed_payment_base_key.write(writer)?;
705 self.htlc_base_key.write(writer)?;
706 self.commitment_seed.write(writer)?;
707 self.channel_parameters.write(writer)?;
708 self.channel_value_satoshis.write(writer)?;
709 self.channel_keys_id.write(writer)?;
711 write_tlv_fields!(writer, {});
717 impl Readable for InMemorySigner {
718 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
719 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
721 let funding_key = Readable::read(reader)?;
722 let revocation_base_key = Readable::read(reader)?;
723 let payment_key = Readable::read(reader)?;
724 let delayed_payment_base_key = Readable::read(reader)?;
725 let htlc_base_key = Readable::read(reader)?;
726 let commitment_seed = Readable::read(reader)?;
727 let counterparty_channel_data = Readable::read(reader)?;
728 let channel_value_satoshis = Readable::read(reader)?;
729 let secp_ctx = Secp256k1::signing_only();
730 let holder_channel_pubkeys =
731 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
732 &payment_key, &delayed_payment_base_key,
734 let keys_id = Readable::read(reader)?;
736 read_tlv_fields!(reader, {});
742 delayed_payment_base_key,
745 channel_value_satoshis,
746 holder_channel_pubkeys,
747 channel_parameters: counterparty_channel_data,
748 channel_keys_id: keys_id,
753 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
754 /// and derives keys from that.
756 /// Your node_id is seed/0'
757 /// ChannelMonitor closes may use seed/1'
758 /// Cooperative closes may use seed/2'
759 /// The two close keys may be needed to claim on-chain funds!
760 pub struct KeysManager {
761 secp_ctx: Secp256k1<secp256k1::All>,
762 node_secret: SecretKey,
763 destination_script: Script,
764 shutdown_pubkey: PublicKey,
765 channel_master_key: ExtendedPrivKey,
766 channel_child_index: AtomicUsize,
768 rand_bytes_master_key: ExtendedPrivKey,
769 rand_bytes_child_index: AtomicUsize,
770 rand_bytes_unique_start: Sha256State,
773 starting_time_secs: u64,
774 starting_time_nanos: u32,
778 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
779 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
780 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
781 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
782 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
783 /// simply use the current time (with very high precision).
785 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
786 /// obviously, starting_time should be unique every time you reload the library - it is only
787 /// used to generate new ephemeral key data (which will be stored by the individual channel if
790 /// Note that the seed is required to recover certain on-chain funds independent of
791 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
792 /// channel, and some on-chain during-closing funds.
794 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
795 /// versions. Once the library is more fully supported, the docs will be updated to include a
796 /// detailed description of the guarantee.
797 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
798 let secp_ctx = Secp256k1::new();
799 // Note that when we aren't serializing the key, network doesn't matter
800 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
802 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
803 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
804 Ok(destination_key) => {
805 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
806 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
807 .push_slice(&wpubkey_hash.into_inner())
810 Err(_) => panic!("Your RNG is busted"),
812 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
813 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
814 Err(_) => panic!("Your RNG is busted"),
816 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
817 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
819 let mut rand_bytes_unique_start = Sha256::engine();
820 rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
821 rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
822 rand_bytes_unique_start.input(seed);
824 let mut res = KeysManager {
832 channel_child_index: AtomicUsize::new(0),
834 rand_bytes_master_key,
835 rand_bytes_child_index: AtomicUsize::new(0),
836 rand_bytes_unique_start,
842 let secp_seed = res.get_secure_random_bytes();
843 res.secp_ctx.seeded_randomize(&secp_seed);
846 Err(_) => panic!("Your rng is busted"),
849 /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
851 /// Key derivation parameters are accessible through a per-channel secrets
852 /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
853 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
854 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
855 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
856 assert!(chan_id <= core::u32::MAX as u64); // Otherwise the params field wasn't created by us
857 let mut unique_start = Sha256::engine();
858 unique_start.input(params);
859 unique_start.input(&self.seed);
861 // We only seriously intend to rely on the channel_master_key for true secure
862 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
863 // starting_time provided in the constructor) to be unique.
864 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");
865 unique_start.input(&child_privkey.private_key.key[..]);
867 let seed = Sha256::from_engine(unique_start).into_inner();
869 let commitment_seed = {
870 let mut sha = Sha256::engine();
872 sha.input(&b"commitment seed"[..]);
873 Sha256::from_engine(sha).into_inner()
875 macro_rules! key_step {
876 ($info: expr, $prev_key: expr) => {{
877 let mut sha = Sha256::engine();
879 sha.input(&$prev_key[..]);
880 sha.input(&$info[..]);
881 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
884 let funding_key = key_step!(b"funding key", commitment_seed);
885 let revocation_base_key = key_step!(b"revocation base key", funding_key);
886 let payment_key = key_step!(b"payment key", revocation_base_key);
887 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
888 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
895 delayed_payment_base_key,
898 channel_value_satoshis,
903 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
904 /// output to the given change destination (if sufficient change value remains). The
905 /// transaction will have a feerate, at least, of the given value.
907 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
908 /// if a descriptor was duplicated.
910 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
912 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
913 /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
914 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, ()> {
915 let mut input = Vec::new();
916 let mut input_value = 0;
917 let mut witness_weight = 0;
918 let mut output_set = HashSet::with_capacity(descriptors.len());
919 for outp in descriptors {
921 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
923 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
924 script_sig: Script::new(),
928 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
929 input_value += descriptor.output.value;
930 if !output_set.insert(descriptor.outpoint) { return Err(()); }
932 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
934 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
935 script_sig: Script::new(),
936 sequence: descriptor.to_self_delay as u32,
939 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
940 input_value += descriptor.output.value;
941 if !output_set.insert(descriptor.outpoint) { return Err(()); }
943 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
945 previous_output: outpoint.into_bitcoin_outpoint(),
946 script_sig: Script::new(),
950 witness_weight += 1 + 73 + 34;
951 input_value += output.value;
952 if !output_set.insert(*outpoint) { return Err(()); }
955 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
957 let mut spend_tx = Transaction {
963 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
965 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
966 let mut input_idx = 0;
967 for outp in descriptors {
969 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
970 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
972 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
973 descriptor.channel_keys_id));
975 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
977 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
978 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
980 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
981 descriptor.channel_keys_id));
983 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
985 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
986 let derivation_idx = if output.script_pubkey == self.destination_script {
992 // Note that when we aren't serializing the key, network doesn't matter
993 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
995 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
997 Err(_) => panic!("Your RNG is busted"),
1000 Err(_) => panic!("Your rng is busted"),
1003 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
1004 if derivation_idx == 2 {
1005 assert_eq!(pubkey.key, self.shutdown_pubkey);
1007 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1008 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
1009 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
1010 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
1011 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
1012 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1021 impl KeysInterface for KeysManager {
1022 type Signer = InMemorySigner;
1024 fn get_node_secret(&self) -> SecretKey {
1025 self.node_secret.clone()
1028 fn get_destination_script(&self) -> Script {
1029 self.destination_script.clone()
1032 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1033 ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
1036 fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
1037 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1038 assert!(child_ix <= core::u32::MAX as usize);
1039 let mut id = [0; 32];
1040 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1041 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1042 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1043 self.derive_channel_keys(channel_value_satoshis, &id)
1046 fn get_secure_random_bytes(&self) -> [u8; 32] {
1047 let mut sha = self.rand_bytes_unique_start.clone();
1049 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1050 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");
1051 sha.input(&child_privkey.private_key.key[..]);
1053 sha.input(b"Unique Secure Random Bytes Salt");
1054 Sha256::from_engine(sha).into_inner()
1057 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1058 InMemorySigner::read(&mut io::Cursor::new(reader))
1061 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
1062 Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
1066 // Ensure that BaseSign can have a vtable
1069 let _signer: Box<dyn BaseSign>;