use crate::chain::transaction::OutPoint;
use crate::crypto::utils::{hkdf_extract_expand_twice, sign, sign_with_aux_rand};
use crate::ln::chan_utils::{
- make_funding_redeemscript, ChannelPublicKeys, ChannelTransactionParameters, ClosingTransaction,
- CommitmentTransaction, HTLCOutputInCommitment, HolderCommitmentTransaction,
+ get_revokeable_redeemscript, make_funding_redeemscript, ChannelPublicKeys,
+ ChannelTransactionParameters, ClosingTransaction, CommitmentTransaction,
+ HTLCOutputInCommitment, HolderCommitmentTransaction,
};
use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
use crate::ln::channel_keys::{
- DelayedPaymentBasepoint, DelayedPaymentKey, HtlcBasepoint, HtlcKey, RevocationBasepoint,
- RevocationKey,
+ add_public_key_tweak, DelayedPaymentBasepoint, DelayedPaymentKey, HtlcBasepoint, HtlcKey,
+ RevocationBasepoint, RevocationKey,
};
#[cfg(taproot)]
use crate::ln::msgs::PartialSignatureWithNonce;
use crate::sign::taproot::TaprootChannelSigner;
use crate::util::atomic_counter::AtomicCounter;
use crate::util::invoice::construct_invoice_preimage;
+use core::convert::TryInto;
use core::ops::Deref;
use core::sync::atomic::{AtomicUsize, Ordering};
#[cfg(taproot)]
pub channel_keys_id: [u8; 32],
/// The value of the channel which this output originated from, possibly indirectly.
pub channel_value_satoshis: u64,
+ /// The channel public keys and other parameters needed to generate a spending transaction or to provide to a re-derived signer through
+ /// [`ChannelSigner::provide_channel_parameters`].
+ ///
+ /// Added as optional, but always `Some` if the descriptor was produced in v0.0.123 or later.
+ pub channel_transaction_parameters: Option<ChannelTransactionParameters>,
}
+
impl DelayedPaymentOutputDescriptor {
/// The maximum length a well-formed witness spending one of these should have.
/// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
(8, revocation_pubkey, required),
(10, channel_keys_id, required),
(12, channel_value_satoshis, required),
+ (13, channel_transaction_parameters, option),
});
pub(crate) const P2WPKH_WITNESS_WEIGHT: u64 = 1 /* num stack items */ +
1 /* pubkey length */ +
33 /* pubkey */;
+/// Witness weight for satisying a P2TR key-path spend.
+pub(crate) const P2TR_KEY_PATH_WITNESS_WEIGHT: u64 = 1 /* witness items */
+ + 1 /* schnorr sig len */ + 64 /* schnorr sig */;
+
/// Information about a spendable output to our "payment key".
///
/// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
/// Added as optional, but always `Some` if the descriptor was produced in v0.0.117 or later.
pub channel_transaction_parameters: Option<ChannelTransactionParameters>,
}
+
impl StaticPaymentOutputDescriptor {
/// Returns the `witness_script` of the spendable output.
///
///
/// This is not exported to bindings users as there is no standard serialization for an input.
/// See [`Self::create_spendable_outputs_psbt`] instead.
- pub fn to_psbt_input(&self) -> bitcoin::psbt::Input {
+ ///
+ /// The proprietary field is used to store add tweak for the signing key of this transaction.
+ /// See the [`DelayedPaymentBasepoint::derive_add_tweak`] docs for more info on add tweak and how to use it.
+ ///
+ /// To get the proprietary field use:
+ /// ```
+ /// use bitcoin::psbt::{PartiallySignedTransaction};
+ /// use bitcoin::hashes::hex::FromHex;
+ ///
+ /// # let s = "70736274ff0100520200000001dee978529ab3e61a2987bea5183713d0e6d5ceb5ac81100fdb54a1a2\
+ /// # 69cef505000000000090000000011f26000000000000160014abb3ab63280d4ccc5c11d6b50fd427a8\
+ /// # e19d6470000000000001012b10270000000000002200200afe4736760d814a2651bae63b572d935d9a\
+ /// # b74a1a16c01774e341a32afa763601054d63210394a27a700617f5b7aee72bd4f8076b5770a582b7fb\
+ /// # d1d4ee2ea3802cd3cfbe2067029000b27521034629b1c8fdebfaeb58a74cd181f485e2c462e594cb30\
+ /// # 34dee655875f69f6c7c968ac20fc144c444b5f7370656e6461626c655f6f7574707574006164645f74\
+ /// # 7765616b20a86534f38ad61dc580ef41c3886204adf0911b81619c1ad7a2f5b5de39a2ba600000";
+ /// # let psbt = PartiallySignedTransaction::deserialize(<Vec<u8> as FromHex>::from_hex(s).unwrap().as_slice()).unwrap();
+ /// let key = bitcoin::psbt::raw::ProprietaryKey {
+ /// prefix: "LDK_spendable_output".as_bytes().to_vec(),
+ /// subtype: 0,
+ /// key: "add_tweak".as_bytes().to_vec(),
+ /// };
+ /// let value = psbt
+ /// .inputs
+ /// .first()
+ /// .expect("Unable to get add tweak as there are no inputs")
+ /// .proprietary
+ /// .get(&key)
+ /// .map(|x| x.to_owned());
+ /// ```
+ pub fn to_psbt_input<T: secp256k1::Signing>(
+ &self, secp_ctx: &Secp256k1<T>,
+ ) -> bitcoin::psbt::Input {
match self {
SpendableOutputDescriptor::StaticOutput { output, .. } => {
// Is a standard P2WPKH, no need for witness script
bitcoin::psbt::Input { witness_utxo: Some(output.clone()), ..Default::default() }
},
- SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
- // TODO we could add the witness script as well
+ SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
+ channel_transaction_parameters,
+ per_commitment_point,
+ revocation_pubkey,
+ to_self_delay,
+ output,
+ ..
+ }) => {
+ let delayed_payment_basepoint = channel_transaction_parameters
+ .as_ref()
+ .map(|params| params.holder_pubkeys.delayed_payment_basepoint);
+
+ let (witness_script, add_tweak) =
+ if let Some(basepoint) = delayed_payment_basepoint.as_ref() {
+ // Required to derive signing key: privkey = basepoint_secret + SHA256(per_commitment_point || basepoint)
+ let add_tweak = basepoint.derive_add_tweak(&per_commitment_point);
+ let payment_key = DelayedPaymentKey(add_public_key_tweak(
+ secp_ctx,
+ &basepoint.to_public_key(),
+ &add_tweak,
+ ));
+
+ (
+ Some(get_revokeable_redeemscript(
+ &revocation_pubkey,
+ *to_self_delay,
+ &payment_key,
+ )),
+ Some(add_tweak),
+ )
+ } else {
+ (None, None)
+ };
+
bitcoin::psbt::Input {
- witness_utxo: Some(descriptor.output.clone()),
+ witness_utxo: Some(output.clone()),
+ witness_script,
+ proprietary: add_tweak
+ .map(|add_tweak| {
+ [(
+ bitcoin::psbt::raw::ProprietaryKey {
+ // A non standard namespace for spendable outputs, used to store the tweak needed
+ // to derive the private key
+ prefix: "LDK_spendable_output".as_bytes().to_vec(),
+ subtype: 0,
+ key: "add_tweak".as_bytes().to_vec(),
+ },
+ add_tweak.to_vec(),
+ )]
+ .into_iter()
+ .collect()
+ })
+ .unwrap_or_default(),
..Default::default()
}
},
- SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
- // TODO we could add the witness script as well
- bitcoin::psbt::Input {
- witness_utxo: Some(descriptor.output.clone()),
- ..Default::default()
- }
+ SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => bitcoin::psbt::Input {
+ witness_utxo: Some(descriptor.output.clone()),
+ witness_script: descriptor.witness_script(),
+ ..Default::default()
},
}
}
/// does not match the one we can spend.
///
/// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
- pub fn create_spendable_outputs_psbt(
- descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+ pub fn create_spendable_outputs_psbt<T: secp256k1::Signing>(
+ secp_ctx: &Secp256k1<T>, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
locktime: Option<LockTime>,
) -> Result<(PartiallySignedTransaction, u64), ()> {
change_destination_script,
)?;
- let psbt_inputs = descriptors.iter().map(|d| d.to_psbt_input()).collect::<Vec<_>>();
+ let psbt_inputs =
+ descriptors.iter().map(|d| d.to_psbt_input(&secp_ctx)).collect::<Vec<_>>();
let psbt = PartiallySignedTransaction {
inputs: psbt_inputs,
outputs: vec![Default::default(); tx.output.len()],
fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
}
+/// A trait that describes a wallet capable of creating a spending [`Transaction`] from a set of
+/// [`SpendableOutputDescriptor`]s.
+pub trait OutputSpender {
+ /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
+ /// output to the given change destination (if sufficient change value remains). The
+ /// transaction will have a feerate, at least, of the given value.
+ ///
+ /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
+ /// transaction will have a locktime of 0. It it recommended to set this to the current block
+ /// height to avoid fee sniping, unless you have some specific reason to use a different
+ /// locktime.
+ ///
+ /// Returns `Err(())` if the output value is greater than the input value minus required fee,
+ /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
+ /// does not match the one we can spend.
+ fn spend_spendable_outputs<C: Signing>(
+ &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+ change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
+ locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>,
+ ) -> Result<Transaction, ()>;
+}
+
// Primarily needed in doctests because of https://github.com/rust-lang/rust/issues/67295
/// A dynamic [`SignerProvider`] temporarily needed for doc tests.
#[cfg(taproot)]
fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
}
+/// A helper trait that describes an on-chain wallet capable of returning a (change) destination
+/// script.
+pub trait ChangeDestinationSource {
+ /// Returns a script pubkey which can be used as a change destination for
+ /// [`OutputSpender::spend_spendable_outputs`].
+ ///
+ /// This method should return a different value each time it is called, to avoid linking
+ /// on-chain funds controlled to the same user.
+ fn get_change_destination_script(&self) -> Result<ScriptBuf, ()>;
+}
+
/// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
///
/// This implementation performs no policy checks and is insufficient by itself as
Ok(psbt)
}
-
- /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
- /// output to the given change destination (if sufficient change value remains). The
- /// transaction will have a feerate, at least, of the given value.
- ///
- /// The `locktime` argument is used to set the transaction's locktime. If `None`, the
- /// transaction will have a locktime of 0. It it recommended to set this to the current block
- /// height to avoid fee sniping, unless you have some specific reason to use a different
- /// locktime.
- ///
- /// Returns `Err(())` if the output value is greater than the input value minus required fee,
- /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
- /// does not match the one we can spend.
- ///
- /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
- ///
- /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
- /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
- pub fn spend_spendable_outputs<C: Signing>(
- &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
- change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
- locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>,
- ) -> Result<Transaction, ()> {
- let (mut psbt, expected_max_weight) =
- SpendableOutputDescriptor::create_spendable_outputs_psbt(
- descriptors,
- outputs,
- change_destination_script,
- feerate_sat_per_1000_weight,
- locktime,
- )?;
- psbt = self.sign_spendable_outputs_psbt(descriptors, psbt, secp_ctx)?;
-
- let spend_tx = psbt.extract_tx();
-
- debug_assert!(expected_max_weight >= spend_tx.weight().to_wu());
- // Note that witnesses with a signature vary somewhat in size, so allow
- // `expected_max_weight` to overshoot by up to 3 bytes per input.
- debug_assert!(
- expected_max_weight <= spend_tx.weight().to_wu() + descriptors.len() as u64 * 3
- );
-
- Ok(spend_tx)
- }
}
impl EntropySource for KeysManager {
}
}
+impl OutputSpender for KeysManager {
+ /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
+ /// output to the given change destination (if sufficient change value remains).
+ ///
+ /// See [`OutputSpender::spend_spendable_outputs`] documentation for more information.
+ ///
+ /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
+ ///
+ /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
+ /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
+ fn spend_spendable_outputs<C: Signing>(
+ &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+ change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
+ locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>,
+ ) -> Result<Transaction, ()> {
+ let (mut psbt, expected_max_weight) =
+ SpendableOutputDescriptor::create_spendable_outputs_psbt(
+ secp_ctx,
+ descriptors,
+ outputs,
+ change_destination_script,
+ feerate_sat_per_1000_weight,
+ locktime,
+ )?;
+ psbt = self.sign_spendable_outputs_psbt(descriptors, psbt, secp_ctx)?;
+
+ let spend_tx = psbt.extract_tx();
+
+ debug_assert!(expected_max_weight >= spend_tx.weight().to_wu());
+ // Note that witnesses with a signature vary somewhat in size, so allow
+ // `expected_max_weight` to overshoot by up to 3 bytes per input.
+ debug_assert!(
+ expected_max_weight <= spend_tx.weight().to_wu() + descriptors.len() as u64 * 3
+ );
+
+ Ok(spend_tx)
+ }
+}
+
impl SignerProvider for KeysManager {
type EcdsaSigner = InMemorySigner;
#[cfg(taproot)]
}
}
+impl OutputSpender for PhantomKeysManager {
+ /// See [`OutputSpender::spend_spendable_outputs`] and [`KeysManager::spend_spendable_outputs`]
+ /// for documentation on this method.
+ fn spend_spendable_outputs<C: Signing>(
+ &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+ change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
+ locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>,
+ ) -> Result<Transaction, ()> {
+ self.inner.spend_spendable_outputs(
+ descriptors,
+ outputs,
+ change_destination_script,
+ feerate_sat_per_1000_weight,
+ locktime,
+ secp_ctx,
+ )
+ }
+}
+
impl SignerProvider for PhantomKeysManager {
type EcdsaSigner = InMemorySigner;
#[cfg(taproot)]
}
}
- /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
- pub fn spend_spendable_outputs<C: Signing>(
- &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
- change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
- locktime: Option<LockTime>, secp_ctx: &Secp256k1<C>,
- ) -> Result<Transaction, ()> {
- self.inner.spend_spendable_outputs(
- descriptors,
- outputs,
- change_destination_script,
- feerate_sat_per_1000_weight,
- locktime,
- secp_ctx,
- )
- }
-
/// See [`KeysManager::derive_channel_keys`] for documentation on this method.
pub fn derive_channel_keys(
&self, channel_value_satoshis: u64, params: &[u8; 32],
projects / rust-lightning / blobdiff