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, ClosingTransaction};
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 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
47 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
48 /// (C-not exported) as we just use [u8; 32] directly
49 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
50 pub struct KeyMaterial(pub [u8; 32]);
52 /// Information about a spendable output to a P2WSH script. See
53 /// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
54 #[derive(Clone, Debug, PartialEq)]
55 pub struct DelayedPaymentOutputDescriptor {
56 /// The outpoint which is spendable
57 pub outpoint: OutPoint,
58 /// Per commitment point to derive delayed_payment_key by key holder
59 pub per_commitment_point: PublicKey,
60 /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
61 /// the witness_script.
62 pub to_self_delay: u16,
63 /// The output which is referenced by the given outpoint
65 /// The revocation point specific to the commitment transaction which was broadcast. Used to
66 /// derive the witnessScript for this output.
67 pub revocation_pubkey: PublicKey,
68 /// Arbitrary identification information returned by a call to
69 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
70 /// the channel to spend the output.
71 pub channel_keys_id: [u8; 32],
72 /// The value of the channel which this output originated from, possibly indirectly.
73 pub channel_value_satoshis: u64,
75 impl DelayedPaymentOutputDescriptor {
76 /// The maximum length a well-formed witness spending one of these should have.
77 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
78 // redeemscript push length.
79 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
82 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
83 (0, outpoint, required),
84 (2, per_commitment_point, required),
85 (4, to_self_delay, required),
86 (6, output, required),
87 (8, revocation_pubkey, required),
88 (10, channel_keys_id, required),
89 (12, channel_value_satoshis, required),
92 /// Information about a spendable output to our "payment key". See
93 /// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
94 #[derive(Clone, Debug, PartialEq)]
95 pub struct StaticPaymentOutputDescriptor {
96 /// The outpoint which is spendable
97 pub outpoint: OutPoint,
98 /// The output which is referenced by the given outpoint
100 /// Arbitrary identification information returned by a call to
101 /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
102 /// the channel to spend the output.
103 pub channel_keys_id: [u8; 32],
104 /// The value of the channel which this transactions spends.
105 pub channel_value_satoshis: u64,
107 impl StaticPaymentOutputDescriptor {
108 /// The maximum length a well-formed witness spending one of these should have.
109 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
110 // redeemscript push length.
111 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
113 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
114 (0, outpoint, required),
115 (2, output, required),
116 (4, channel_keys_id, required),
117 (6, channel_value_satoshis, required),
120 /// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
121 /// claim at any point in the future) an event is generated which you must track and be able to
122 /// spend on-chain. The information needed to do this is provided in this enum, including the
123 /// outpoint describing which txid and output index is available, the full output which exists at
124 /// that txid/index, and any keys or other information required to sign.
125 #[derive(Clone, Debug, PartialEq)]
126 pub enum SpendableOutputDescriptor {
127 /// An output to a script which was provided via KeysInterface directly, either from
128 /// `get_destination_script()` or `get_shutdown_scriptpubkey()`, thus you should already know
129 /// how to spend it. No secret keys are provided as rust-lightning was never given any key.
130 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
131 /// on-chain using the payment preimage or after it has timed out.
133 /// The outpoint which is spendable
135 /// The output which is referenced by the given outpoint.
138 /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
140 /// The witness in the spending input should be:
141 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
143 /// Note that the nSequence field in the spending input must be set to to_self_delay
144 /// (which means the transaction is not broadcastable until at least to_self_delay
145 /// blocks after the outpoint confirms).
147 /// These are generally the result of a "revocable" output to us, spendable only by us unless
148 /// it is an output from an old state which we broadcast (which should never happen).
150 /// To derive the delayed_payment key which is used to sign for this input, you must pass the
151 /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
152 /// Sign::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to
153 /// chan_utils::derive_private_key. The public key can be generated without the secret key
154 /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in
157 /// To derive the revocation_pubkey provided here (which is used in the witness
158 /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
159 /// call to Sign::ready_channel) and the provided per_commitment point
160 /// to chan_utils::derive_public_revocation_key.
162 /// The witness script which is hashed and included in the output script_pubkey may be
163 /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey
164 /// (derived as above), and the to_self_delay contained here to
165 /// chan_utils::get_revokeable_redeemscript.
166 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
167 /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which
168 /// corresponds to the public key in Sign::pubkeys().payment_point).
169 /// The witness in the spending input, is, thus, simply:
170 /// <BIP 143 signature> <payment key>
172 /// These are generally the result of our counterparty having broadcast the current state,
173 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
174 StaticPaymentOutput(StaticPaymentOutputDescriptor),
177 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
178 (0, StaticOutput) => {
179 (0, outpoint, required),
180 (2, output, required),
183 (1, DelayedPaymentOutput),
184 (2, StaticPaymentOutput),
187 /// A trait to sign lightning channel transactions as described in BOLT 3.
189 /// Signing services could be implemented on a hardware wallet. In this case,
190 /// the current Sign would be a front-end on top of a communication
191 /// channel connected to your secure device and lightning key material wouldn't
192 /// reside on a hot server. Nevertheless, a this deployment would still need
193 /// to trust the ChannelManager to avoid loss of funds as this latest component
194 /// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
196 /// A more secure iteration would be to use hashlock (or payment points) to pair
197 /// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
198 /// at the price of more state and computation on the hardware wallet side. In the future,
199 /// we are looking forward to design such interface.
201 /// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
202 /// to act, as liveness and breach reply correctness are always going to be hard requirements
203 /// of LN security model, orthogonal of key management issues.
204 // TODO: We should remove Clone by instead requesting a new Sign copy when we create
205 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
207 /// Gets the per-commitment point for a specific commitment number
209 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
210 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
211 /// Gets the commitment secret for a specific commitment number as part of the revocation process
213 /// An external signer implementation should error here if the commitment was already signed
214 /// and should refuse to sign it in the future.
216 /// May be called more than once for the same index.
218 /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
219 // TODO: return a Result so we can signal a validation error
220 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
221 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
223 /// This is required in order for the signer to make sure that releasing a commitment
224 /// secret won't leave us without a broadcastable holder transaction.
225 /// Policy checks should be implemented in this function, including checking the amount
226 /// sent to us and checking the HTLCs.
227 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction) -> Result<(), ()>;
228 /// Gets the holder's channel public keys and basepoints
229 fn pubkeys(&self) -> &ChannelPublicKeys;
230 /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
231 /// some SpendableOutputDescriptor types. This should be sufficient to identify this
232 /// Sign object uniquely and lookup or re-derive its keys.
233 fn channel_keys_id(&self) -> [u8; 32];
235 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
237 /// Note that if signing fails or is rejected, the channel will be force-closed.
239 /// Policy checks should be implemented in this function, including checking the amount
240 /// sent to us and checking the HTLCs.
242 // TODO: Document the things someone using this interface should enforce before signing.
243 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
244 /// Validate the counterparty's revocation.
246 /// This is required in order for the signer to make sure that the state has moved
247 /// forward and it is safe to sign the next counterparty commitment.
248 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
250 /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
251 /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
252 /// latest commitment_tx when we initiate a force-close.
253 /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
254 /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
256 /// This may be called multiple times for the same transaction.
258 /// An external signer implementation should check that the commitment has not been revoked.
260 /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
262 // TODO: Document the things someone using this interface should enforce before signing.
263 // TODO: Key derivation failure should panic rather than Err
264 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
266 /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment
267 /// transactions which will be broadcasted later, after the channel has moved on to a newer
268 /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever
270 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
271 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
273 /// Create a signature for the given input in a transaction spending an HTLC transaction output
274 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
276 /// A justice transaction may claim multiple outputs at the same time if timelocks are
277 /// similar, but only a signature for the input at index `input` should be signed for here.
278 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
279 /// to an upcoming timelock expiration.
281 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
283 /// per_commitment_key is revocation secret which was provided by our counterparty when they
284 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
285 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
287 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
289 /// Create a signature for the given input in a transaction spending a commitment transaction
290 /// HTLC output when our counterparty broadcasts an old state.
292 /// A justice transaction may claim multiple outputs at the same time if timelocks are
293 /// similar, but only a signature for the input at index `input` should be signed for here.
294 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
295 /// to an upcoming timelock expiration.
297 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
299 /// per_commitment_key is revocation secret which was provided by our counterparty when they
300 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
301 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
304 /// htlc holds HTLC elements (hash, timelock), thus changing the format of the witness script
305 /// (which is committed to in the BIP 143 signatures).
306 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, ()>;
308 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
309 /// transaction, either offered or received.
311 /// Such a transaction may claim multiples offered outputs at same time if we know the
312 /// preimage for each when we create it, but only the input at index `input` should be
313 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
314 /// needed with regards to an upcoming timelock expiration.
316 /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC
319 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
321 /// Per_commitment_point is the dynamic point corresponding to the channel state
322 /// detected onchain. It has been generated by our counterparty and is used to derive
323 /// channel state keys, which are then included in the witness script and committed to in the
324 /// BIP 143 signature.
325 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, ()>;
327 /// Create a signature for a (proposed) closing transaction.
329 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
330 /// chosen to forgo their output as dust.
331 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
333 /// Signs a channel announcement message with our funding key, proving it comes from one
334 /// of the channel participants.
336 /// Note that if this fails or is rejected, the channel will not be publicly announced and
337 /// our counterparty may (though likely will not) close the channel on us for violating the
339 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
341 /// Set the counterparty static channel data, including basepoints,
342 /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
343 /// This is done as soon as the funding outpoint is known. Since these are static channel data,
344 /// they MUST NOT be allowed to change to different values once set.
346 /// channel_parameters.is_populated() MUST be true.
348 /// We bind holder_selected_contest_delay late here for API convenience.
350 /// Will be called before any signatures are applied.
351 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
354 /// A cloneable signer.
356 /// Although we require signers to be cloneable, it may be useful for developers to be able to use
357 /// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
358 /// which implies Sized, into this derived trait.
359 pub trait Sign: BaseSign + Writeable + Clone {
362 /// A trait to describe an object which can get user secrets and key material.
363 pub trait KeysInterface {
364 /// A type which implements Sign which will be returned by get_channel_signer.
367 /// Get node secret key (aka node_id or network_key).
369 /// This method must return the same value each time it is called.
370 fn get_node_secret(&self) -> SecretKey;
371 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
373 /// This method should return a different value each time it is called, to avoid linking
374 /// on-chain funds across channels as controlled to the same user.
375 fn get_destination_script(&self) -> Script;
376 /// Get a script pubkey which we will send funds to when closing a channel.
378 /// This method should return a different value each time it is called, to avoid linking
379 /// on-chain funds across channels as controlled to the same user.
380 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
381 /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
382 /// restarted with some stale data!
384 /// This method must return a different value each time it is called.
385 fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
386 /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
387 /// onion packets and for temporary channel IDs. There is no requirement that these be
388 /// persisted anywhere, though they must be unique across restarts.
390 /// This method must return a different value each time it is called.
391 fn get_secure_random_bytes(&self) -> [u8; 32];
393 /// Reads a `Signer` for this `KeysInterface` from the given input stream.
394 /// This is only called during deserialization of other objects which contain
395 /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
396 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
397 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
398 /// you've read all of the provided bytes to ensure no corruption occurred.
399 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
401 /// Sign an invoice's preimage (note that this is the preimage of the invoice, not the HTLC's
402 /// preimage). By parameterizing by the preimage instead of the hash, we allow implementors of
403 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
404 /// blindly signing the hash.
405 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()>;
407 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
409 /// This method must return the same value each time it is called.
410 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
414 /// A simple implementation of Sign that just keeps the private keys in memory.
416 /// This implementation performs no policy checks and is insufficient by itself as
417 /// a secure external signer.
418 pub struct InMemorySigner {
419 /// Private key of anchor tx
420 pub funding_key: SecretKey,
421 /// Holder secret key for blinded revocation pubkey
422 pub revocation_base_key: SecretKey,
423 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
424 pub payment_key: SecretKey,
425 /// Holder secret key used in HTLC tx
426 pub delayed_payment_base_key: SecretKey,
427 /// Holder htlc secret key used in commitment tx htlc outputs
428 pub htlc_base_key: SecretKey,
430 pub commitment_seed: [u8; 32],
431 /// Holder public keys and basepoints
432 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
433 /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
434 channel_parameters: Option<ChannelTransactionParameters>,
435 /// The total value of this channel
436 channel_value_satoshis: u64,
437 /// Key derivation parameters
438 channel_keys_id: [u8; 32],
441 impl InMemorySigner {
442 /// Create a new InMemorySigner
443 pub fn new<C: Signing>(
444 secp_ctx: &Secp256k1<C>,
445 funding_key: SecretKey,
446 revocation_base_key: SecretKey,
447 payment_key: SecretKey,
448 delayed_payment_base_key: SecretKey,
449 htlc_base_key: SecretKey,
450 commitment_seed: [u8; 32],
451 channel_value_satoshis: u64,
452 channel_keys_id: [u8; 32]) -> InMemorySigner {
453 let holder_channel_pubkeys =
454 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
455 &payment_key, &delayed_payment_base_key,
461 delayed_payment_base_key,
464 channel_value_satoshis,
465 holder_channel_pubkeys,
466 channel_parameters: None,
471 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
472 funding_key: &SecretKey,
473 revocation_base_key: &SecretKey,
474 payment_key: &SecretKey,
475 delayed_payment_base_key: &SecretKey,
476 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
477 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
479 funding_pubkey: from_secret(&funding_key),
480 revocation_basepoint: from_secret(&revocation_base_key),
481 payment_point: from_secret(&payment_key),
482 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
483 htlc_basepoint: from_secret(&htlc_base_key),
487 /// Counterparty pubkeys.
488 /// Will panic if ready_channel wasn't called.
489 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
491 /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
492 /// transactions, ie the amount of time that we have to wait to recover our funds if we
493 /// broadcast a transaction.
494 /// Will panic if ready_channel wasn't called.
495 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
497 /// The contest_delay value specified by us and applied on transactions broadcastable
498 /// by our counterparty, ie the amount of time that they have to wait to recover their funds
499 /// if they broadcast a transaction.
500 /// Will panic if ready_channel wasn't called.
501 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
503 /// Whether the holder is the initiator
504 /// Will panic if ready_channel wasn't called.
505 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
508 /// Will panic if ready_channel wasn't called.
509 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
511 /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
512 /// building transactions.
514 /// Will panic if ready_channel wasn't called.
515 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
516 self.channel_parameters.as_ref().unwrap()
519 /// Whether anchors should be used.
520 /// Will panic if ready_channel wasn't called.
521 pub fn opt_anchors(&self) -> bool {
522 self.get_channel_parameters().opt_anchors.is_some()
525 /// Sign the single input of spend_tx at index `input_idx` which spends the output
526 /// described by descriptor, returning the witness stack for the input.
528 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
529 /// or is not spending the outpoint described by `descriptor.outpoint`.
530 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
531 // TODO: We really should be taking the SigHashCache as a parameter here instead of
532 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
533 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
534 // bindings updates to support SigHashCache objects).
535 if spend_tx.input.len() <= input_idx { return Err(()); }
536 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
537 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
539 let remotepubkey = self.pubkeys().payment_point;
540 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
541 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
542 let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
544 let mut witness = Vec::with_capacity(2);
545 witness.push(remotesig.serialize_der().to_vec());
546 witness[0].push(SigHashType::All as u8);
547 witness.push(remotepubkey.serialize().to_vec());
551 /// Sign the single input of spend_tx at index `input_idx` which spends the output
552 /// described by descriptor, returning the witness stack for the input.
554 /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
555 /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
556 /// sequence set to `descriptor.to_self_delay`.
557 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
558 // TODO: We really should be taking the SigHashCache as a parameter here instead of
559 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
560 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
561 // bindings updates to support SigHashCache objects).
562 if spend_tx.input.len() <= input_idx { return Err(()); }
563 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
564 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
565 if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
567 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
568 .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
569 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
570 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
571 let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
572 let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
574 let mut witness = Vec::with_capacity(3);
575 witness.push(local_delayedsig.serialize_der().to_vec());
576 witness[0].push(SigHashType::All as u8);
577 witness.push(vec!()); //MINIMALIF
578 witness.push(witness_script.clone().into_bytes());
583 impl BaseSign for InMemorySigner {
584 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
585 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
586 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
589 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
590 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
593 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction) -> Result<(), ()> {
597 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
598 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
600 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
601 let trusted_tx = commitment_tx.trust();
602 let keys = trusted_tx.keys();
604 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
605 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
607 let built_tx = trusted_tx.built_transaction();
608 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
609 let commitment_txid = built_tx.txid;
611 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
612 for htlc in commitment_tx.htlcs() {
613 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
614 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
615 let htlc_sighashtype = if self.opt_anchors() { SigHashType::SinglePlusAnyoneCanPay } else { SigHashType::All };
616 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype)[..]);
617 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
618 htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
621 Ok((commitment_sig, htlc_sigs))
624 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
628 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
629 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
630 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
631 let trusted_tx = commitment_tx.trust();
632 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
633 let channel_parameters = self.get_channel_parameters();
634 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
638 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
639 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
640 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
641 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
642 let trusted_tx = commitment_tx.trust();
643 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
644 let channel_parameters = self.get_channel_parameters();
645 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
649 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
650 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
651 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
652 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
653 let witness_script = {
654 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_err(|_| ())?;
655 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
657 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
658 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
659 return Ok(secp_ctx.sign(&sighash, &revocation_key))
662 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, ()> {
663 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
664 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
665 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
666 let witness_script = {
667 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
668 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
669 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
671 let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
672 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
673 return Ok(secp_ctx.sign(&sighash, &revocation_key))
676 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, ()> {
677 if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
678 let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
679 if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
680 if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
681 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
682 } else { return Err(()) }
683 } else { return Err(()) }
684 } else { return Err(()) };
685 let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
686 let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
687 return Ok(secp_ctx.sign(&sighash, &htlc_key))
692 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
693 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
694 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
695 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
698 fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
699 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
700 Ok(secp_ctx.sign(&msghash, &self.funding_key))
703 fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
704 assert!(self.channel_parameters.is_none(), "Acceptance already noted");
705 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
706 self.channel_parameters = Some(channel_parameters.clone());
710 const SERIALIZATION_VERSION: u8 = 1;
711 const MIN_SERIALIZATION_VERSION: u8 = 1;
713 impl Sign for InMemorySigner {}
715 impl Writeable for InMemorySigner {
716 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
717 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
719 self.funding_key.write(writer)?;
720 self.revocation_base_key.write(writer)?;
721 self.payment_key.write(writer)?;
722 self.delayed_payment_base_key.write(writer)?;
723 self.htlc_base_key.write(writer)?;
724 self.commitment_seed.write(writer)?;
725 self.channel_parameters.write(writer)?;
726 self.channel_value_satoshis.write(writer)?;
727 self.channel_keys_id.write(writer)?;
729 write_tlv_fields!(writer, {});
735 impl Readable for InMemorySigner {
736 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
737 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
739 let funding_key = Readable::read(reader)?;
740 let revocation_base_key = Readable::read(reader)?;
741 let payment_key = Readable::read(reader)?;
742 let delayed_payment_base_key = Readable::read(reader)?;
743 let htlc_base_key = Readable::read(reader)?;
744 let commitment_seed = Readable::read(reader)?;
745 let counterparty_channel_data = Readable::read(reader)?;
746 let channel_value_satoshis = Readable::read(reader)?;
747 let secp_ctx = Secp256k1::signing_only();
748 let holder_channel_pubkeys =
749 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
750 &payment_key, &delayed_payment_base_key,
752 let keys_id = Readable::read(reader)?;
754 read_tlv_fields!(reader, {});
760 delayed_payment_base_key,
763 channel_value_satoshis,
764 holder_channel_pubkeys,
765 channel_parameters: counterparty_channel_data,
766 channel_keys_id: keys_id,
771 /// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
772 /// and derives keys from that.
774 /// Your node_id is seed/0'
775 /// ChannelMonitor closes may use seed/1'
776 /// Cooperative closes may use seed/2'
777 /// The two close keys may be needed to claim on-chain funds!
778 pub struct KeysManager {
779 secp_ctx: Secp256k1<secp256k1::All>,
780 node_secret: SecretKey,
781 inbound_payment_key: KeyMaterial,
782 destination_script: Script,
783 shutdown_pubkey: PublicKey,
784 channel_master_key: ExtendedPrivKey,
785 channel_child_index: AtomicUsize,
787 rand_bytes_master_key: ExtendedPrivKey,
788 rand_bytes_child_index: AtomicUsize,
789 rand_bytes_unique_start: Sha256State,
792 starting_time_secs: u64,
793 starting_time_nanos: u32,
797 /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
798 /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
799 /// starting_time isn't strictly required to actually be a time, but it must absolutely,
800 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
801 /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
802 /// simply use the current time (with very high precision).
804 /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
805 /// obviously, starting_time should be unique every time you reload the library - it is only
806 /// used to generate new ephemeral key data (which will be stored by the individual channel if
809 /// Note that the seed is required to recover certain on-chain funds independent of
810 /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
811 /// channel, and some on-chain during-closing funds.
813 /// Note that until the 0.1 release there is no guarantee of backward compatibility between
814 /// versions. Once the library is more fully supported, the docs will be updated to include a
815 /// detailed description of the guarantee.
816 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
817 let secp_ctx = Secp256k1::new();
818 // Note that when we aren't serializing the key, network doesn't matter
819 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
821 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
822 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
823 Ok(destination_key) => {
824 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
825 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
826 .push_slice(&wpubkey_hash.into_inner())
829 Err(_) => panic!("Your RNG is busted"),
831 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
832 Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
833 Err(_) => panic!("Your RNG is busted"),
835 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
836 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
837 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key.key;
838 let mut inbound_pmt_key_bytes = [0; 32];
839 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
841 let mut rand_bytes_unique_start = Sha256::engine();
842 rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
843 rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
844 rand_bytes_unique_start.input(seed);
846 let mut res = KeysManager {
849 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
855 channel_child_index: AtomicUsize::new(0),
857 rand_bytes_master_key,
858 rand_bytes_child_index: AtomicUsize::new(0),
859 rand_bytes_unique_start,
865 let secp_seed = res.get_secure_random_bytes();
866 res.secp_ctx.seeded_randomize(&secp_seed);
869 Err(_) => panic!("Your rng is busted"),
872 /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
874 /// Key derivation parameters are accessible through a per-channel secrets
875 /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
876 /// onchain output detection for which a corresponding delayed_payment_key must be derived.
877 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
878 let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
879 assert!(chan_id <= core::u32::MAX as u64); // Otherwise the params field wasn't created by us
880 let mut unique_start = Sha256::engine();
881 unique_start.input(params);
882 unique_start.input(&self.seed);
884 // We only seriously intend to rely on the channel_master_key for true secure
885 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
886 // starting_time provided in the constructor) to be unique.
887 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");
888 unique_start.input(&child_privkey.private_key.key[..]);
890 let seed = Sha256::from_engine(unique_start).into_inner();
892 let commitment_seed = {
893 let mut sha = Sha256::engine();
895 sha.input(&b"commitment seed"[..]);
896 Sha256::from_engine(sha).into_inner()
898 macro_rules! key_step {
899 ($info: expr, $prev_key: expr) => {{
900 let mut sha = Sha256::engine();
902 sha.input(&$prev_key[..]);
903 sha.input(&$info[..]);
904 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
907 let funding_key = key_step!(b"funding key", commitment_seed);
908 let revocation_base_key = key_step!(b"revocation base key", funding_key);
909 let payment_key = key_step!(b"payment key", revocation_base_key);
910 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
911 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
918 delayed_payment_base_key,
921 channel_value_satoshis,
926 /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
927 /// output to the given change destination (if sufficient change value remains). The
928 /// transaction will have a feerate, at least, of the given value.
930 /// Returns `Err(())` if the output value is greater than the input value minus required fee or
931 /// if a descriptor was duplicated.
933 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
935 /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
936 /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
937 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, ()> {
938 let mut input = Vec::new();
939 let mut input_value = 0;
940 let mut witness_weight = 0;
941 let mut output_set = HashSet::with_capacity(descriptors.len());
942 for outp in descriptors {
944 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
946 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
947 script_sig: Script::new(),
951 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
952 input_value += descriptor.output.value;
953 if !output_set.insert(descriptor.outpoint) { return Err(()); }
955 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
957 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
958 script_sig: Script::new(),
959 sequence: descriptor.to_self_delay as u32,
962 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
963 input_value += descriptor.output.value;
964 if !output_set.insert(descriptor.outpoint) { return Err(()); }
966 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
968 previous_output: outpoint.into_bitcoin_outpoint(),
969 script_sig: Script::new(),
973 witness_weight += 1 + 73 + 34;
974 input_value += output.value;
975 if !output_set.insert(*outpoint) { return Err(()); }
978 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
980 let mut spend_tx = Transaction {
986 let expected_max_weight =
987 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
989 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
990 let mut input_idx = 0;
991 for outp in descriptors {
993 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
994 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
996 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
997 descriptor.channel_keys_id));
999 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
1001 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1002 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1004 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1005 descriptor.channel_keys_id));
1007 spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
1009 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
1010 let derivation_idx = if output.script_pubkey == self.destination_script {
1016 // Note that when we aren't serializing the key, network doesn't matter
1017 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1019 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1021 Err(_) => panic!("Your RNG is busted"),
1024 Err(_) => panic!("Your rng is busted"),
1027 let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
1028 if derivation_idx == 2 {
1029 assert_eq!(pubkey.key, self.shutdown_pubkey);
1031 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1032 let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
1033 let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
1034 spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
1035 spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
1036 spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
1042 debug_assert!(expected_max_weight >= spend_tx.get_weight());
1043 // Note that witnesses with a signature vary somewhat in size, so allow
1044 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1045 debug_assert!(expected_max_weight <= spend_tx.get_weight() + descriptors.len() * 3);
1051 impl KeysInterface for KeysManager {
1052 type Signer = InMemorySigner;
1054 fn get_node_secret(&self) -> SecretKey {
1055 self.node_secret.clone()
1058 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1059 self.inbound_payment_key.clone()
1062 fn get_destination_script(&self) -> Script {
1063 self.destination_script.clone()
1066 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1067 ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
1070 fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
1071 let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1072 assert!(child_ix <= core::u32::MAX as usize);
1073 let mut id = [0; 32];
1074 id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
1075 id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
1076 id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
1077 self.derive_channel_keys(channel_value_satoshis, &id)
1080 fn get_secure_random_bytes(&self) -> [u8; 32] {
1081 let mut sha = self.rand_bytes_unique_start.clone();
1083 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1084 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");
1085 sha.input(&child_privkey.private_key.key[..]);
1087 sha.input(b"Unique Secure Random Bytes Salt");
1088 Sha256::from_engine(sha).into_inner()
1091 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1092 InMemorySigner::read(&mut io::Cursor::new(reader))
1095 fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
1096 Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
1100 // Ensure that BaseSign can have a vtable
1103 let _signer: Box<dyn BaseSign>;