X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fsign%2Fmod.rs;h=43acc67af04b3699ef406a8dc64113908463b357;hb=e08f7de3faafffebd21b1606d0c7aa07f1fe7159;hp=5b42796a94f9586fe2dd42fd7210fada4be7297f;hpb=8a42d555086a89274fa90f1e667a17eea62555ab;p=rust-lightning diff --git a/lightning/src/sign/mod.rs b/lightning/src/sign/mod.rs index 5b42796a..43acc67a 100644 --- a/lightning/src/sign/mod.rs +++ b/lightning/src/sign/mod.rs @@ -12,52 +12,75 @@ //! The provided output descriptors follow a custom LDK data format and are currently not fully //! compatible with Bitcoin Core output descriptors. -use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, EcdsaSighashType}; -use bitcoin::blockdata::script::{Script, Builder}; +use bitcoin::bip32::{ChildNumber, ExtendedPrivKey, ExtendedPubKey}; +use bitcoin::blockdata::locktime::absolute::LockTime; use bitcoin::blockdata::opcodes; +use bitcoin::blockdata::script::{Builder, Script, ScriptBuf}; +use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut}; +use bitcoin::ecdsa::Signature as EcdsaSignature; use bitcoin::network::constants::Network; use bitcoin::psbt::PartiallySignedTransaction; -use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber}; -use bitcoin::util::sighash; +use bitcoin::sighash; +use bitcoin::sighash::EcdsaSighashType; use bitcoin::bech32::u5; -use bitcoin::hashes::{Hash, HashEngine}; +use bitcoin::hash_types::WPubkeyHash; use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::hashes::sha256d::Hash as Sha256dHash; -use bitcoin::hash_types::WPubkeyHash; +use bitcoin::hashes::{Hash, HashEngine}; -use bitcoin::secp256k1::{KeyPair, PublicKey, Scalar, Secp256k1, SecretKey, Signing}; use bitcoin::secp256k1::ecdh::SharedSecret; use bitcoin::secp256k1::ecdsa::{RecoverableSignature, Signature}; use bitcoin::secp256k1::schnorr; -use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness}; +#[cfg(taproot)] +use bitcoin::secp256k1::All; +use bitcoin::secp256k1::{KeyPair, PublicKey, Scalar, Secp256k1, SecretKey, Signing}; +use bitcoin::{secp256k1, Sequence, Txid, Witness}; -use crate::util::transaction_utils; -use crate::util::crypto::{hkdf_extract_expand_twice, sign, sign_with_aux_rand}; -use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs}; use crate::chain::transaction::OutPoint; -use crate::events::bump_transaction::HTLCDescriptor; +use crate::crypto::utils::{hkdf_extract_expand_twice, sign, sign_with_aux_rand}; +use crate::ln::chan_utils::{ + get_revokeable_redeemscript, make_funding_redeemscript, ChannelPublicKeys, + ChannelTransactionParameters, ClosingTransaction, CommitmentTransaction, + HTLCOutputInCommitment, HolderCommitmentTransaction, +}; use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI; -use crate::ln::{chan_utils, PaymentPreimage}; -use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction}; +use crate::ln::channel_keys::{ + add_public_key_tweak, DelayedPaymentBasepoint, DelayedPaymentKey, HtlcBasepoint, HtlcKey, + RevocationBasepoint, RevocationKey, +}; +#[cfg(taproot)] +use crate::ln::msgs::PartialSignatureWithNonce; use crate::ln::msgs::{UnsignedChannelAnnouncement, UnsignedGossipMessage}; use crate::ln::script::ShutdownScript; +use crate::ln::{chan_utils, PaymentPreimage}; use crate::offers::invoice::UnsignedBolt12Invoice; use crate::offers::invoice_request::UnsignedInvoiceRequest; +use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer}; +use crate::util::transaction_utils; -use crate::prelude::*; -use core::convert::TryInto; -use core::ops::Deref; -use core::sync::atomic::{AtomicUsize, Ordering}; +use crate::crypto::chacha20::ChaCha20; use crate::io::{self, Error}; use crate::ln::features::ChannelTypeFeatures; use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT}; +use crate::prelude::*; +use crate::sign::ecdsa::{EcdsaChannelSigner, WriteableEcdsaChannelSigner}; +#[cfg(taproot)] +use crate::sign::taproot::TaprootChannelSigner; use crate::util::atomic_counter::AtomicCounter; -use crate::util::chacha20::ChaCha20; use crate::util::invoice::construct_invoice_preimage; +use core::convert::TryInto; +use core::ops::Deref; +use core::sync::atomic::{AtomicUsize, Ordering}; +#[cfg(taproot)] +use musig2::types::{PartialSignature, PublicNonce}; pub(crate) mod type_resolver; +pub mod ecdsa; +#[cfg(taproot)] +pub mod taproot; + /// Used as initial key material, to be expanded into multiple secret keys (but not to be used /// directly). This is used within LDK to encrypt/decrypt inbound payment data. /// @@ -81,20 +104,27 @@ pub struct DelayedPaymentOutputDescriptor { pub output: TxOut, /// The revocation point specific to the commitment transaction which was broadcast. Used to /// derive the witnessScript for this output. - pub revocation_pubkey: PublicKey, + pub revocation_pubkey: RevocationKey, /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`]. /// This may be useful in re-deriving keys used in the channel to spend the output. 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, } + 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 /// shorter. // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus // redeemscript push length. - pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1; + pub const MAX_WITNESS_LENGTH: u64 = + 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH as u64 + 1; } impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, { @@ -105,8 +135,15 @@ impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, { (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 /* sig length */ + + 73 /* sig including sighash flag */ + + 1 /* pubkey length */ + + 33 /* pubkey */; + /// Information about a spendable output to our "payment key". /// /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this. @@ -121,20 +158,49 @@ pub struct StaticPaymentOutputDescriptor { pub channel_keys_id: [u8; 32], /// The value of the channel which this transactions spends. pub channel_value_satoshis: u64, + /// The necessary channel parameters that need to be provided to the re-derived signer through + /// [`ChannelSigner::provide_channel_parameters`]. + /// + /// Added as optional, but always `Some` if the descriptor was produced in v0.0.117 or later. + pub channel_transaction_parameters: Option, } + impl StaticPaymentOutputDescriptor { + /// Returns the `witness_script` of the spendable output. + /// + /// Note that this will only return `Some` for [`StaticPaymentOutputDescriptor`]s that + /// originated from an anchor outputs channel, as they take the form of a P2WSH script. + pub fn witness_script(&self) -> Option { + self.channel_transaction_parameters.as_ref().and_then(|channel_params| { + if channel_params.supports_anchors() { + let payment_point = channel_params.holder_pubkeys.payment_point; + Some(chan_utils::get_to_countersignatory_with_anchors_redeemscript(&payment_point)) + } else { + None + } + }) + } + /// 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 /// shorter. - // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus - // redeemscript push length. - pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34; + pub fn max_witness_length(&self) -> u64 { + if self.channel_transaction_parameters.as_ref().map_or(false, |p| p.supports_anchors()) { + let witness_script_weight = 1 /* pubkey push */ + 33 /* pubkey */ + + 1 /* OP_CHECKSIGVERIFY */ + 1 /* OP_1 */ + 1 /* OP_CHECKSEQUENCEVERIFY */; + 1 /* num witness items */ + 1 /* sig push */ + 73 /* sig including sighash flag */ + + 1 /* witness script push */ + witness_script_weight + } else { + P2WPKH_WITNESS_WEIGHT + } + } } impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, { (0, outpoint, required), (2, output, required), (4, channel_keys_id, required), (6, channel_value_satoshis, required), + (7, channel_transaction_parameters, option), }); /// Describes the necessary information to spend a spendable output. @@ -161,6 +227,15 @@ pub enum SpendableOutputDescriptor { outpoint: OutPoint, /// The output which is referenced by the given outpoint. output: TxOut, + /// The `channel_keys_id` for the channel which this output came from. + /// + /// For channels which were generated on LDK 0.0.119 or later, this is the value which was + /// passed to the [`SignerProvider::get_destination_script`] call which provided this + /// output script. + /// + /// For channels which were generated prior to LDK 0.0.119, no such argument existed, + /// however this field may still be filled in if such data is available. + channel_keys_id: Option<[u8; 32]>, }, /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV` /// delay. @@ -184,8 +259,8 @@ pub enum SpendableOutputDescriptor { /// To derive the delayed payment key which is used to sign this input, you must pass the /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`ChannelSigner::pubkeys`]) and the provided - /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The public key can be - /// generated without the secret key using [`chan_utils::derive_public_key`] and only the + /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The DelayedPaymentKey can be + /// generated without the secret key using [`DelayedPaymentKey::from_basepoint`] and only the /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`]. /// /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is @@ -193,7 +268,7 @@ pub enum SpendableOutputDescriptor { /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to /// [`ChannelSigner::provide_channel_parameters`]) and the provided /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to - /// [`chan_utils::derive_public_revocation_key`]. + /// [`RevocationKey`]. /// /// The witness script which is hashed and included in the output `script_pubkey` may be /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived @@ -201,21 +276,30 @@ pub enum SpendableOutputDescriptor { /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to /// [`chan_utils::get_revokeable_redeemscript`]. DelayedPaymentOutput(DelayedPaymentOutputDescriptor), - /// An output to a P2WPKH, spendable exclusively by our payment key (i.e., the private key - /// which corresponds to the `payment_point` in [`ChannelSigner::pubkeys`]). The witness - /// in the spending input is, thus, simply: + /// An output spendable exclusively by our payment key (i.e., the private key that corresponds + /// to the `payment_point` in [`ChannelSigner::pubkeys`]). The output type depends on the + /// channel type negotiated. + /// + /// On an anchor outputs channel, the witness in the spending input is: + /// ```bitcoin + /// + /// ``` + /// + /// Otherwise, it is: /// ```bitcoin /// /// ``` /// /// These are generally the result of our counterparty having broadcast the current state, - /// allowing us to claim the non-HTLC-encumbered outputs immediately. + /// allowing us to claim the non-HTLC-encumbered outputs immediately, or after one confirmation + /// in the case of anchor outputs channels. StaticPaymentOutput(StaticPaymentOutputDescriptor), } impl_writeable_tlv_based_enum!(SpendableOutputDescriptor, (0, StaticOutput) => { (0, outpoint, required), + (1, channel_keys_id, option), (2, output, required), }, ; @@ -229,28 +313,107 @@ impl SpendableOutputDescriptor { /// /// Note that this does not include any signatures, just the information required to /// construct the transaction and sign it. - pub fn to_psbt_input(&self) -> bitcoin::psbt::Input { + /// + /// This is not exported to bindings users as there is no standard serialization for an input. + /// See [`Self::create_spendable_outputs_psbt`] instead. + /// + /// 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( 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( + &self, secp_ctx: &Secp256k1, + ) -> 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() - } + 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() }, } } @@ -271,65 +434,101 @@ impl SpendableOutputDescriptor { /// 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, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option) -> Result<(PartiallySignedTransaction, usize), ()> { + pub fn create_spendable_outputs_psbt( + secp_ctx: &Secp256k1, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, + change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, + locktime: Option, + ) -> Result<(PartiallySignedTransaction, u64), ()> { let mut input = Vec::with_capacity(descriptors.len()); let mut input_value = 0; let mut witness_weight = 0; - let mut output_set = HashSet::with_capacity(descriptors.len()); + let mut output_set = hash_set_with_capacity(descriptors.len()); for outp in descriptors { match outp { SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => { - if !output_set.insert(descriptor.outpoint) { return Err(()); } + if !output_set.insert(descriptor.outpoint) { + return Err(()); + } + let sequence = if descriptor + .channel_transaction_parameters + .as_ref() + .map_or(false, |p| p.supports_anchors()) + { + Sequence::from_consensus(1) + } else { + Sequence::ZERO + }; input.push(TxIn { previous_output: descriptor.outpoint.into_bitcoin_outpoint(), - script_sig: Script::new(), - sequence: Sequence::ZERO, + script_sig: ScriptBuf::new(), + sequence, witness: Witness::new(), }); - witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH; + witness_weight += descriptor.max_witness_length(); #[cfg(feature = "grind_signatures")] - { witness_weight -= 1; } // Guarantees a low R signature + { + // Guarantees a low R signature + witness_weight -= 1; + } input_value += descriptor.output.value; }, SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => { - if !output_set.insert(descriptor.outpoint) { return Err(()); } + if !output_set.insert(descriptor.outpoint) { + return Err(()); + } input.push(TxIn { previous_output: descriptor.outpoint.into_bitcoin_outpoint(), - script_sig: Script::new(), + script_sig: ScriptBuf::new(), sequence: Sequence(descriptor.to_self_delay as u32), witness: Witness::new(), }); witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH; #[cfg(feature = "grind_signatures")] - { witness_weight -= 1; } // Guarantees a low R signature + { + // Guarantees a low R signature + witness_weight -= 1; + } input_value += descriptor.output.value; }, - SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => { - if !output_set.insert(*outpoint) { return Err(()); } + SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output, .. } => { + if !output_set.insert(*outpoint) { + return Err(()); + } input.push(TxIn { previous_output: outpoint.into_bitcoin_outpoint(), - script_sig: Script::new(), + script_sig: ScriptBuf::new(), sequence: Sequence::ZERO, witness: Witness::new(), }); witness_weight += 1 + 73 + 34; #[cfg(feature = "grind_signatures")] - { witness_weight -= 1; } // Guarantees a low R signature + { + // Guarantees a low R signature + witness_weight -= 1; + } input_value += output.value; - } + }, + } + if input_value > MAX_VALUE_MSAT / 1000 { + return Err(()); } - if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); } } let mut tx = Transaction { version: 2, - lock_time: locktime.unwrap_or(PackedLockTime::ZERO), + lock_time: locktime.unwrap_or(LockTime::ZERO), input, output: outputs, }; - let expected_max_weight = - transaction_utils::maybe_add_change_output(&mut tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?; - - let psbt_inputs = descriptors.iter().map(|d| d.to_psbt_input()).collect::>(); + let expected_max_weight = transaction_utils::maybe_add_change_output( + &mut tx, + input_value, + witness_weight, + feerate_sat_per_1000_weight, + change_destination_script, + )?; + + let psbt_inputs = + descriptors.iter().map(|d| d.to_psbt_input(&secp_ctx)).collect::>(); let psbt = PartiallySignedTransaction { inputs: psbt_inputs, outputs: vec![Default::default(); tx.output.len()], @@ -343,13 +542,192 @@ impl SpendableOutputDescriptor { } } +/// The parameters required to derive a channel signer via [`SignerProvider`]. +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct ChannelDerivationParameters { + /// The value in satoshis of the channel we're attempting to spend the anchor output of. + pub value_satoshis: u64, + /// The unique identifier to re-derive the signer for the associated channel. + pub keys_id: [u8; 32], + /// The necessary channel parameters that need to be provided to the re-derived signer through + /// [`ChannelSigner::provide_channel_parameters`]. + pub transaction_parameters: ChannelTransactionParameters, +} + +impl_writeable_tlv_based!(ChannelDerivationParameters, { + (0, value_satoshis, required), + (2, keys_id, required), + (4, transaction_parameters, required), +}); + +/// A descriptor used to sign for a commitment transaction's HTLC output. +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct HTLCDescriptor { + /// The parameters required to derive the signer for the HTLC input. + pub channel_derivation_parameters: ChannelDerivationParameters, + /// The txid of the commitment transaction in which the HTLC output lives. + pub commitment_txid: Txid, + /// The number of the commitment transaction in which the HTLC output lives. + pub per_commitment_number: u64, + /// The key tweak corresponding to the number of the commitment transaction in which the HTLC + /// output lives. This tweak is applied to all the basepoints for both parties in the channel to + /// arrive at unique keys per commitment. + /// + /// See for more info. + pub per_commitment_point: PublicKey, + /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs + /// originating from a channel supporting anchor outputs, otherwise it is the channel's + /// negotiated feerate at the time the commitment transaction was built. + pub feerate_per_kw: u32, + /// The details of the HTLC as it appears in the commitment transaction. + pub htlc: HTLCOutputInCommitment, + /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be + /// taken. + pub preimage: Option, + /// The counterparty's signature required to spend the HTLC output. + pub counterparty_sig: Signature, +} + +impl_writeable_tlv_based!(HTLCDescriptor, { + (0, channel_derivation_parameters, required), + (1, feerate_per_kw, (default_value, 0)), + (2, commitment_txid, required), + (4, per_commitment_number, required), + (6, per_commitment_point, required), + (8, htlc, required), + (10, preimage, option), + (12, counterparty_sig, required), +}); + +impl HTLCDescriptor { + /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint + /// being spent by the HTLC input in the HTLC transaction. + pub fn outpoint(&self) -> bitcoin::OutPoint { + bitcoin::OutPoint { + txid: self.commitment_txid, + vout: self.htlc.transaction_output_index.unwrap(), + } + } + + /// Returns the UTXO to be spent by the HTLC input, which can be obtained via + /// [`Self::unsigned_tx_input`]. + pub fn previous_utxo( + &self, secp: &Secp256k1, + ) -> TxOut { + TxOut { + script_pubkey: self.witness_script(secp).to_v0_p2wsh(), + value: self.htlc.amount_msat / 1000, + } + } + + /// Returns the unsigned transaction input spending the HTLC output in the commitment + /// transaction. + pub fn unsigned_tx_input(&self) -> TxIn { + chan_utils::build_htlc_input( + &self.commitment_txid, + &self.htlc, + &self.channel_derivation_parameters.transaction_parameters.channel_type_features, + ) + } + + /// Returns the delayed output created as a result of spending the HTLC output in the commitment + /// transaction. + pub fn tx_output( + &self, secp: &Secp256k1, + ) -> TxOut { + let channel_params = + self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); + let broadcaster_keys = channel_params.broadcaster_pubkeys(); + let counterparty_keys = channel_params.countersignatory_pubkeys(); + let broadcaster_delayed_key = DelayedPaymentKey::from_basepoint( + secp, + &broadcaster_keys.delayed_payment_basepoint, + &self.per_commitment_point, + ); + let counterparty_revocation_key = &RevocationKey::from_basepoint( + &secp, + &counterparty_keys.revocation_basepoint, + &self.per_commitment_point, + ); + chan_utils::build_htlc_output( + self.feerate_per_kw, + channel_params.contest_delay(), + &self.htlc, + channel_params.channel_type_features(), + &broadcaster_delayed_key, + &counterparty_revocation_key, + ) + } + + /// Returns the witness script of the HTLC output in the commitment transaction. + pub fn witness_script( + &self, secp: &Secp256k1, + ) -> ScriptBuf { + let channel_params = + self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); + let broadcaster_keys = channel_params.broadcaster_pubkeys(); + let counterparty_keys = channel_params.countersignatory_pubkeys(); + let broadcaster_htlc_key = HtlcKey::from_basepoint( + secp, + &broadcaster_keys.htlc_basepoint, + &self.per_commitment_point, + ); + let counterparty_htlc_key = HtlcKey::from_basepoint( + secp, + &counterparty_keys.htlc_basepoint, + &self.per_commitment_point, + ); + let counterparty_revocation_key = &RevocationKey::from_basepoint( + &secp, + &counterparty_keys.revocation_basepoint, + &self.per_commitment_point, + ); + chan_utils::get_htlc_redeemscript_with_explicit_keys( + &self.htlc, + channel_params.channel_type_features(), + &broadcaster_htlc_key, + &counterparty_htlc_key, + &counterparty_revocation_key, + ) + } + + /// Returns the fully signed witness required to spend the HTLC output in the commitment + /// transaction. + pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness { + chan_utils::build_htlc_input_witness( + signature, + &self.counterparty_sig, + &self.preimage, + witness_script, + &self.channel_derivation_parameters.transaction_parameters.channel_type_features, + ) + } + + /// Derives the channel signer required to sign the HTLC input. + pub fn derive_channel_signer( + &self, signer_provider: &SP, + ) -> S + where + SP::Target: SignerProvider, + { + let mut signer = signer_provider.derive_channel_signer( + self.channel_derivation_parameters.value_satoshis, + self.channel_derivation_parameters.keys_id, + ); + signer + .provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters); + signer + } +} + /// A trait to handle Lightning channel key material without concretizing the channel type or /// the signature mechanism. pub trait ChannelSigner { /// Gets the per-commitment point for a specific commitment number /// /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards. - fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1) -> PublicKey; + fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1) + -> PublicKey; /// Gets the commitment secret for a specific commitment number as part of the revocation process /// @@ -369,14 +747,22 @@ pub trait ChannelSigner { /// Policy checks should be implemented in this function, including checking the amount /// sent to us and checking the HTLCs. /// - /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided. + /// The preimages of outbound HTLCs that were fulfilled since the last commitment are provided. /// A validating signer should ensure that an HTLC output is removed only when the matching /// preimage is provided, or when the value to holder is restored. /// /// Note that all the relevant preimages will be provided, but there may also be additional /// irrelevant or duplicate preimages. - fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction, - preimages: Vec) -> Result<(), ()>; + fn validate_holder_commitment( + &self, holder_tx: &HolderCommitmentTransaction, + outbound_htlc_preimages: Vec, + ) -> Result<(), ()>; + + /// Validate the counterparty's revocation. + /// + /// This is required in order for the signer to make sure that the state has moved + /// forward and it is safe to sign the next counterparty commitment. + fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>; /// Returns the holder's channel public keys and basepoints. fn pubkeys(&self) -> &ChannelPublicKeys; @@ -398,164 +784,6 @@ pub trait ChannelSigner { fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters); } -/// A trait to sign Lightning channel transactions as described in -/// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md). -/// -/// Signing services could be implemented on a hardware wallet and should implement signing -/// policies in order to be secure. Please refer to the [VLS Policy -/// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md) -/// for an example of such policies. -pub trait EcdsaChannelSigner: ChannelSigner { - /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions. - /// - /// Note that if signing fails or is rejected, the channel will be force-closed. - /// - /// Policy checks should be implemented in this function, including checking the amount - /// sent to us and checking the HTLCs. - /// - /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided. - /// A validating signer should ensure that an HTLC output is removed only when the matching - /// preimage is provided, or when the value to holder is restored. - /// - /// Note that all the relevant preimages will be provided, but there may also be additional - /// irrelevant or duplicate preimages. - // - // TODO: Document the things someone using this interface should enforce before signing. - fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, - preimages: Vec, secp_ctx: &Secp256k1 - ) -> Result<(Signature, Vec), ()>; - /// Validate the counterparty's revocation. - /// - /// This is required in order for the signer to make sure that the state has moved - /// forward and it is safe to sign the next counterparty commitment. - fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>; - /// Creates a signature for a holder's commitment transaction and its claiming HTLC transactions. - /// - /// This will be called - /// - with a non-revoked `commitment_tx`. - /// - with the latest `commitment_tx` when we initiate a force-close. - /// - with the previous `commitment_tx`, just to get claiming HTLC - /// signatures, if we are reacting to a [`ChannelMonitor`] - /// [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas) - /// that decided to broadcast before it had been updated to the latest `commitment_tx`. - /// - /// This may be called multiple times for the same transaction. - /// - /// An external signer implementation should check that the commitment has not been revoked. - /// - /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor - // TODO: Document the things someone using this interface should enforce before signing. - fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, - secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; - /// Same as [`sign_holder_commitment_and_htlcs`], but exists only for tests to get access to - /// holder commitment transactions which will be broadcasted later, after the channel has moved - /// on to a newer state. Thus, needs its own method as [`sign_holder_commitment_and_htlcs`] may - /// enforce that we only ever get called once. - #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] - fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, - secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; - /// Create a signature for the given input in a transaction spending an HTLC transaction output - /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state. - /// - /// A justice transaction may claim multiple outputs at the same time if timelocks are - /// similar, but only a signature for the input at index `input` should be signed for here. - /// It may be called multiple times for same output(s) if a fee-bump is needed with regards - /// to an upcoming timelock expiration. - /// - /// Amount is value of the output spent by this input, committed to in the BIP 143 signature. - /// - /// `per_commitment_key` is revocation secret which was provided by our counterparty when they - /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does - /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do - /// so). - fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, - per_commitment_key: &SecretKey, secp_ctx: &Secp256k1 - ) -> Result; - /// Create a signature for the given input in a transaction spending a commitment transaction - /// HTLC output when our counterparty broadcasts an old state. - /// - /// A justice transaction may claim multiple outputs at the same time if timelocks are - /// similar, but only a signature for the input at index `input` should be signed for here. - /// It may be called multiple times for same output(s) if a fee-bump is needed with regards - /// to an upcoming timelock expiration. - /// - /// `amount` is the value of the output spent by this input, committed to in the BIP 143 - /// signature. - /// - /// `per_commitment_key` is revocation secret which was provided by our counterparty when they - /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does - /// not allow the spending of any funds by itself (you need our holder revocation_secret to do - /// so). - /// - /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script - /// (which is committed to in the BIP 143 signatures). - fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, - per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, - secp_ctx: &Secp256k1) -> Result; - /// Computes the signature for a commitment transaction's HTLC output used as an input within - /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned - /// must be be computed using [`EcdsaSighashType::All`]. Note that this should only be used to - /// sign HTLC transactions from channels supporting anchor outputs after all additional - /// inputs/outputs have been added to the transaction. - /// - /// [`EcdsaSighashType::All`]: bitcoin::blockdata::transaction::EcdsaSighashType::All - fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, - htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1 - ) -> Result; - /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment - /// transaction, either offered or received. - /// - /// Such a transaction may claim multiples offered outputs at same time if we know the - /// preimage for each when we create it, but only the input at index `input` should be - /// signed for here. It may be called multiple times for same output(s) if a fee-bump is - /// needed with regards to an upcoming timelock expiration. - /// - /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC - /// outputs. - /// - /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature. - /// - /// `per_commitment_point` is the dynamic point corresponding to the channel state - /// detected onchain. It has been generated by our counterparty and is used to derive - /// channel state keys, which are then included in the witness script and committed to in the - /// BIP 143 signature. - fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, - per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, - secp_ctx: &Secp256k1) -> Result; - /// Create a signature for a (proposed) closing transaction. - /// - /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have - /// chosen to forgo their output as dust. - fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, - secp_ctx: &Secp256k1) -> Result; - /// Computes the signature for a commitment transaction's anchor output used as an - /// input within `anchor_tx`, which spends the commitment transaction, at index `input`. - fn sign_holder_anchor_input( - &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1, - ) -> Result; - /// Signs a channel announcement message with our funding key proving it comes from one of the - /// channel participants. - /// - /// Channel announcements also require a signature from each node's network key. Our node - /// signature is computed through [`NodeSigner::sign_gossip_message`]. - /// - /// Note that if this fails or is rejected, the channel will not be publicly announced and - /// our counterparty may (though likely will not) close the channel on us for violating the - /// protocol. - fn sign_channel_announcement_with_funding_key( - &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1 - ) -> Result; -} - -/// A writeable signer. -/// -/// There will always be two instances of a signer per channel, one occupied by the -/// [`ChannelManager`] and another by the channel's [`ChannelMonitor`]. -/// -/// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager -/// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor -pub trait WriteableEcdsaChannelSigner: EcdsaChannelSigner + Writeable {} - /// Specifies the recipient of an invoice. /// /// This indicates to [`NodeSigner::sign_invoice`] what node secret key should be used to sign @@ -609,7 +837,9 @@ pub trait NodeSigner { /// should be resolved to allow LDK to resume forwarding HTLCs. /// /// Errors if the [`Recipient`] variant is not supported by the implementation. - fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result; + fn ecdh( + &self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>, + ) -> Result; /// Sign an invoice. /// @@ -622,7 +852,9 @@ pub trait NodeSigner { /// The secret key used to sign the invoice is dependent on the [`Recipient`]. /// /// Errors if the [`Recipient`] variant is not supported by the implementation. - fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result; + fn sign_invoice( + &self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient, + ) -> Result; /// Signs the [`TaggedHash`] of a BOLT 12 invoice request. /// @@ -636,7 +868,7 @@ pub trait NodeSigner { /// /// [`TaggedHash`]: crate::offers::merkle::TaggedHash fn sign_bolt12_invoice_request( - &self, invoice_request: &UnsignedInvoiceRequest + &self, invoice_request: &UnsignedInvoiceRequest, ) -> Result; /// Signs the [`TaggedHash`] of a BOLT 12 invoice. @@ -651,7 +883,7 @@ pub trait NodeSigner { /// /// [`TaggedHash`]: crate::offers::merkle::TaggedHash fn sign_bolt12_invoice( - &self, invoice: &UnsignedBolt12Invoice + &self, invoice: &UnsignedBolt12Invoice, ) -> Result; /// Sign a gossip message. @@ -663,18 +895,59 @@ pub trait NodeSigner { fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result; } +/// 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( + &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, + change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, + locktime: Option, secp_ctx: &Secp256k1, + ) -> Result; +} + +// Primarily needed in doctests because of https://github.com/rust-lang/rust/issues/67295 +/// A dynamic [`SignerProvider`] temporarily needed for doc tests. +#[cfg(taproot)] +#[doc(hidden)] +#[deprecated(note = "Remove once taproot cfg is removed")] +pub type DynSignerProvider = + dyn SignerProvider; + +/// A dynamic [`SignerProvider`] temporarily needed for doc tests. +#[cfg(not(taproot))] +#[doc(hidden)] +#[deprecated(note = "Remove once taproot cfg is removed")] +pub type DynSignerProvider = dyn SignerProvider; + /// A trait that can return signer instances for individual channels. pub trait SignerProvider { /// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`]. - type Signer : WriteableEcdsaChannelSigner; + type EcdsaSigner: WriteableEcdsaChannelSigner; + #[cfg(taproot)] + /// A type which implements [`TaprootChannelSigner`] + type TaprootSigner: TaprootChannelSigner; - /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::Signer`] through + /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::EcdsaSigner`] through /// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow /// implementations of [`SignerProvider`] to maintain a mapping between itself and the generated /// `channel_keys_id`. /// /// This method must return a different value each time it is called. - fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32]; + fn generate_channel_keys_id( + &self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128, + ) -> [u8; 32]; /// Derives the private key material backing a `Signer`. /// @@ -682,7 +955,9 @@ pub trait SignerProvider { /// [`SignerProvider::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be /// re-derived from its `channel_keys_id`, which can be obtained through its trait method /// [`ChannelSigner::channel_keys_id`]. - fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer; + fn derive_channel_signer( + &self, channel_value_satoshis: u64, channel_keys_id: [u8; 32], + ) -> Self::EcdsaSigner; /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream. /// This is only called during deserialization of other objects which contain @@ -694,18 +969,19 @@ pub trait SignerProvider { /// This method is slowly being phased out -- it will only be called when reading objects /// written by LDK versions prior to 0.0.113. /// - /// [`Signer`]: Self::Signer + /// [`Signer`]: Self::EcdsaSigner /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager - fn read_chan_signer(&self, reader: &[u8]) -> Result; + fn read_chan_signer(&self, reader: &[u8]) -> Result; /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs. /// /// If this function returns an error, this will result in a channel failing to open. /// /// This method should return a different value each time it is called, to avoid linking - /// on-chain funds across channels as controlled to the same user. - fn get_destination_script(&self) -> Result; + /// on-chain funds across channels as controlled to the same user. `channel_keys_id` may be + /// used to derive a unique value for each channel. + fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result; /// Get a script pubkey which we will send funds to when closing a channel. /// @@ -718,6 +994,17 @@ pub trait SignerProvider { fn get_shutdown_scriptpubkey(&self) -> Result; } +/// 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; +} + /// 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 @@ -745,25 +1032,22 @@ pub struct InMemorySigner { channel_value_satoshis: u64, /// Key derivation parameters. channel_keys_id: [u8; 32], - /// Seed from which all randomness produced is derived from. - rand_bytes_unique_start: [u8; 32], - /// Tracks the number of times we've produced randomness to ensure we don't return the same - /// bytes twice. - rand_bytes_index: AtomicCounter, + /// A source of random bytes. + entropy_source: RandomBytes, } impl PartialEq for InMemorySigner { fn eq(&self, other: &Self) -> bool { - self.funding_key == other.funding_key && - self.revocation_base_key == other.revocation_base_key && - self.payment_key == other.payment_key && - self.delayed_payment_base_key == other.delayed_payment_base_key && - self.htlc_base_key == other.htlc_base_key && - self.commitment_seed == other.commitment_seed && - self.holder_channel_pubkeys == other.holder_channel_pubkeys && - self.channel_parameters == other.channel_parameters && - self.channel_value_satoshis == other.channel_value_satoshis && - self.channel_keys_id == other.channel_keys_id + self.funding_key == other.funding_key + && self.revocation_base_key == other.revocation_base_key + && self.payment_key == other.payment_key + && self.delayed_payment_base_key == other.delayed_payment_base_key + && self.htlc_base_key == other.htlc_base_key + && self.commitment_seed == other.commitment_seed + && self.holder_channel_pubkeys == other.holder_channel_pubkeys + && self.channel_parameters == other.channel_parameters + && self.channel_value_satoshis == other.channel_value_satoshis + && self.channel_keys_id == other.channel_keys_id } } @@ -780,8 +1064,7 @@ impl Clone for InMemorySigner { channel_parameters: self.channel_parameters.clone(), channel_value_satoshis: self.channel_value_satoshis, channel_keys_id: self.channel_keys_id, - rand_bytes_unique_start: self.get_secure_random_bytes(), - rand_bytes_index: AtomicCounter::new(), + entropy_source: RandomBytes::new(self.get_secure_random_bytes()), } } } @@ -789,21 +1072,19 @@ impl Clone for InMemorySigner { impl InMemorySigner { /// Creates a new [`InMemorySigner`]. pub fn new( - secp_ctx: &Secp256k1, - funding_key: SecretKey, - revocation_base_key: SecretKey, - payment_key: SecretKey, - delayed_payment_base_key: SecretKey, - htlc_base_key: SecretKey, - commitment_seed: [u8; 32], - channel_value_satoshis: u64, - channel_keys_id: [u8; 32], + secp_ctx: &Secp256k1, funding_key: SecretKey, revocation_base_key: SecretKey, + payment_key: SecretKey, delayed_payment_base_key: SecretKey, htlc_base_key: SecretKey, + commitment_seed: [u8; 32], channel_value_satoshis: u64, channel_keys_id: [u8; 32], rand_bytes_unique_start: [u8; 32], ) -> InMemorySigner { - let holder_channel_pubkeys = - InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key, - &payment_key, &delayed_payment_base_key, - &htlc_base_key); + let holder_channel_pubkeys = InMemorySigner::make_holder_keys( + secp_ctx, + &funding_key, + &revocation_base_key, + &payment_key, + &delayed_payment_base_key, + &htlc_base_key, + ); InMemorySigner { funding_key, revocation_base_key, @@ -815,65 +1096,92 @@ impl InMemorySigner { holder_channel_pubkeys, channel_parameters: None, channel_keys_id, - rand_bytes_unique_start, - rand_bytes_index: AtomicCounter::new(), + entropy_source: RandomBytes::new(rand_bytes_unique_start), } } - fn make_holder_keys(secp_ctx: &Secp256k1, - funding_key: &SecretKey, - revocation_base_key: &SecretKey, - payment_key: &SecretKey, - delayed_payment_base_key: &SecretKey, - htlc_base_key: &SecretKey) -> ChannelPublicKeys { + fn make_holder_keys( + secp_ctx: &Secp256k1, funding_key: &SecretKey, revocation_base_key: &SecretKey, + payment_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, + ) -> ChannelPublicKeys { let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s); ChannelPublicKeys { funding_pubkey: from_secret(&funding_key), - revocation_basepoint: from_secret(&revocation_base_key), + revocation_basepoint: RevocationBasepoint::from(from_secret(&revocation_base_key)), payment_point: from_secret(&payment_key), - delayed_payment_basepoint: from_secret(&delayed_payment_base_key), - htlc_basepoint: from_secret(&htlc_base_key), + delayed_payment_basepoint: DelayedPaymentBasepoint::from(from_secret( + &delayed_payment_base_key, + )), + htlc_basepoint: HtlcBasepoint::from(from_secret(&htlc_base_key)), } } /// Returns the counterparty's pubkeys. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys } + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> { + self.get_channel_parameters().and_then(|params| { + params.counterparty_parameters.as_ref().map(|params| ¶ms.pubkeys) + }) + } + /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable /// transactions, i.e., the amount of time that we have to wait to recover our funds if we /// broadcast a transaction. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay } + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn counterparty_selected_contest_delay(&self) -> Option { + self.get_channel_parameters().and_then(|params| { + params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay) + }) + } + /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds /// if they broadcast a transaction. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay } + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn holder_selected_contest_delay(&self) -> Option { + self.get_channel_parameters().map(|params| params.holder_selected_contest_delay) + } + /// Returns whether the holder is the initiator. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder } + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn is_outbound(&self) -> Option { + self.get_channel_parameters().map(|params| params.is_outbound_from_holder) + } + /// Funding outpoint /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() } + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn funding_outpoint(&self) -> Option<&OutPoint> { + self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten() + } + /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or /// building transactions. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters { - self.channel_parameters.as_ref().unwrap() + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> { + self.channel_parameters.as_ref() } + /// Returns the channel type features of the channel parameters. Should be helpful for /// determining a channel's category, i. e. legacy/anchors/taproot/etc. /// - /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before. - pub fn channel_type_features(&self) -> &ChannelTypeFeatures { - &self.get_channel_parameters().channel_type_features + /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called. + /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation. + pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> { + self.get_channel_parameters().map(|params| ¶ms.channel_type_features) } + /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described /// by `descriptor`, returning the witness stack for the input. /// @@ -882,28 +1190,68 @@ impl InMemorySigner { /// or if an output descriptor `script_pubkey` does not match the one we can spend. /// /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint - pub fn sign_counterparty_payment_input(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1) -> Result>, ()> { + pub fn sign_counterparty_payment_input( + &self, spend_tx: &Transaction, input_idx: usize, + descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1, + ) -> Result { // TODO: We really should be taking the SigHashCache as a parameter here instead of // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only // so that we can check them. This requires upstream rust-bitcoin changes (as well as // bindings updates to support SigHashCache objects). - if spend_tx.input.len() <= input_idx { return Err(()); } - if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); } - if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); } + if spend_tx.input.len() <= input_idx { + return Err(()); + } + if !spend_tx.input[input_idx].script_sig.is_empty() { + return Err(()); + } + if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() + { + return Err(()); + } - let remotepubkey = self.pubkeys().payment_point; - let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Testnet).script_pubkey(); - let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]); + let remotepubkey = bitcoin::PublicKey::new(self.pubkeys().payment_point); + // We cannot always assume that `channel_parameters` is set, so can't just call + // `self.channel_parameters()` or anything that relies on it + let supports_anchors_zero_fee_htlc_tx = self + .channel_type_features() + .map(|features| features.supports_anchors_zero_fee_htlc_tx()) + .unwrap_or(false); + + let witness_script = if supports_anchors_zero_fee_htlc_tx { + chan_utils::get_to_countersignatory_with_anchors_redeemscript(&remotepubkey.inner) + } else { + ScriptBuf::new_p2pkh(&remotepubkey.pubkey_hash()) + }; + let sighash = hash_to_message!( + &sighash::SighashCache::new(spend_tx) + .segwit_signature_hash( + input_idx, + &witness_script, + descriptor.output.value, + EcdsaSighashType::All + ) + .unwrap()[..] + ); let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self); - let payment_script = bitcoin::Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Bitcoin).unwrap().script_pubkey(); + let payment_script = if supports_anchors_zero_fee_htlc_tx { + witness_script.to_v0_p2wsh() + } else { + ScriptBuf::new_v0_p2wpkh(&remotepubkey.wpubkey_hash().unwrap()) + }; - if payment_script != descriptor.output.script_pubkey { return Err(()); } + if payment_script != descriptor.output.script_pubkey { + return Err(()); + } let mut witness = Vec::with_capacity(2); witness.push(remotesig.serialize_der().to_vec()); witness[0].push(EcdsaSighashType::All as u8); - witness.push(remotepubkey.serialize().to_vec()); - Ok(witness) + if supports_anchors_zero_fee_htlc_tx { + witness.push(witness_script.to_bytes()); + } else { + witness.push(remotepubkey.to_bytes()); + } + Ok(witness.into()) } /// Sign the single input of `spend_tx` at index `input_idx` which spends the output @@ -916,46 +1264,82 @@ impl InMemorySigner { /// /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay - pub fn sign_dynamic_p2wsh_input(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1) -> Result>, ()> { + pub fn sign_dynamic_p2wsh_input( + &self, spend_tx: &Transaction, input_idx: usize, + descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1, + ) -> Result { // TODO: We really should be taking the SigHashCache as a parameter here instead of // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only // so that we can check them. This requires upstream rust-bitcoin changes (as well as // bindings updates to support SigHashCache objects). - if spend_tx.input.len() <= input_idx { return Err(()); } - if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); } - if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); } - if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); } - - let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key); - let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key); - let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey); - let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]); - let local_delayedsig = sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self); - let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey(); - - if descriptor.output.script_pubkey != payment_script { return Err(()); } - - let mut witness = Vec::with_capacity(3); - witness.push(local_delayedsig.serialize_der().to_vec()); - witness[0].push(EcdsaSighashType::All as u8); - witness.push(vec!()); //MINIMALIF - witness.push(witness_script.clone().into_bytes()); - Ok(witness) + if spend_tx.input.len() <= input_idx { + return Err(()); + } + if !spend_tx.input[input_idx].script_sig.is_empty() { + return Err(()); + } + if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() + { + return Err(()); + } + if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { + return Err(()); + } + + let delayed_payment_key = chan_utils::derive_private_key( + &secp_ctx, + &descriptor.per_commitment_point, + &self.delayed_payment_base_key, + ); + let delayed_payment_pubkey = + DelayedPaymentKey::from_secret_key(&secp_ctx, &delayed_payment_key); + let witness_script = chan_utils::get_revokeable_redeemscript( + &descriptor.revocation_pubkey, + descriptor.to_self_delay, + &delayed_payment_pubkey, + ); + let sighash = hash_to_message!( + &sighash::SighashCache::new(spend_tx) + .segwit_signature_hash( + input_idx, + &witness_script, + descriptor.output.value, + EcdsaSighashType::All + ) + .unwrap()[..] + ); + let local_delayedsig = EcdsaSignature { + sig: sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self), + hash_ty: EcdsaSighashType::All, + }; + let payment_script = + bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey(); + + if descriptor.output.script_pubkey != payment_script { + return Err(()); + } + + Ok(Witness::from_slice(&[ + &local_delayedsig.serialize()[..], + &[], // MINIMALIF + witness_script.as_bytes(), + ])) } } impl EntropySource for InMemorySigner { fn get_secure_random_bytes(&self) -> [u8; 32] { - let index = self.rand_bytes_index.get_increment(); - let mut nonce = [0u8; 16]; - nonce[..8].copy_from_slice(&index.to_be_bytes()); - ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce) + self.entropy_source.get_secure_random_bytes() } } impl ChannelSigner for InMemorySigner { - fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1) -> PublicKey { - let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap(); + fn get_per_commitment_point( + &self, idx: u64, secp_ctx: &Secp256k1, + ) -> PublicKey { + let commitment_secret = + SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)) + .unwrap(); PublicKey::from_secret_key(secp_ctx, &commitment_secret) } @@ -963,16 +1347,30 @@ impl ChannelSigner for InMemorySigner { chan_utils::build_commitment_secret(&self.commitment_seed, idx) } - fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec) -> Result<(), ()> { + fn validate_holder_commitment( + &self, _holder_tx: &HolderCommitmentTransaction, + _outbound_htlc_preimages: Vec, + ) -> Result<(), ()> { Ok(()) } - fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys } + fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> { + Ok(()) + } - fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id } + fn pubkeys(&self) -> &ChannelPublicKeys { + &self.holder_channel_pubkeys + } + + fn channel_keys_id(&self) -> [u8; 32] { + self.channel_keys_id + } fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) { - assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters); + assert!( + self.channel_parameters.is_none() + || self.channel_parameters.as_ref().unwrap() == channel_parameters + ); if self.channel_parameters.is_some() { // The channel parameters were already set and they match, return early. return; @@ -982,133 +1380,355 @@ impl ChannelSigner for InMemorySigner { } } +const MISSING_PARAMS_ERR: &'static str = + "ChannelSigner::provide_channel_parameters must be called before signing operations"; + impl EcdsaChannelSigner for InMemorySigner { - fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { + fn sign_counterparty_commitment( + &self, commitment_tx: &CommitmentTransaction, + _inbound_htlc_preimages: Vec, + _outbound_htlc_preimages: Vec, secp_ctx: &Secp256k1, + ) -> Result<(Signature, Vec), ()> { let trusted_tx = commitment_tx.trust(); let keys = trusted_tx.keys(); let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let channel_funding_redeemscript = + make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey); let built_tx = trusted_tx.built_transaction(); - let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx); + let commitment_sig = built_tx.sign_counterparty_commitment( + &self.funding_key, + &channel_funding_redeemscript, + self.channel_value_satoshis, + secp_ctx, + ); let commitment_txid = built_tx.txid; let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len()); for htlc in commitment_tx.htlcs() { - let channel_parameters = self.get_channel_parameters(); - let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &channel_parameters.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); - let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.channel_type_features(), &keys); - let htlc_sighashtype = if self.channel_type_features().supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All }; - let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]); - let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key); + let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR); + let holder_selected_contest_delay = + self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR); + let chan_type = &channel_parameters.channel_type_features; + let htlc_tx = chan_utils::build_htlc_transaction( + &commitment_txid, + commitment_tx.feerate_per_kw(), + holder_selected_contest_delay, + htlc, + chan_type, + &keys.broadcaster_delayed_payment_key, + &keys.revocation_key, + ); + let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, chan_type, &keys); + let htlc_sighashtype = if chan_type.supports_anchors_zero_fee_htlc_tx() { + EcdsaSighashType::SinglePlusAnyoneCanPay + } else { + EcdsaSighashType::All + }; + let htlc_sighash = hash_to_message!( + &sighash::SighashCache::new(&htlc_tx) + .segwit_signature_hash( + 0, + &htlc_redeemscript, + htlc.amount_msat / 1000, + htlc_sighashtype + ) + .unwrap()[..] + ); + let holder_htlc_key = chan_utils::derive_private_key( + &secp_ctx, + &keys.per_commitment_point, + &self.htlc_base_key, + ); htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key)); } Ok((commitment_sig, htlc_sigs)) } - fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> { - Ok(()) - } - - fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { + fn sign_holder_commitment( + &self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1, + ) -> Result { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let funding_redeemscript = + make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey); let trusted_tx = commitment_tx.trust(); - let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx); - let channel_parameters = self.get_channel_parameters(); - let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?; - Ok((sig, htlc_sigs)) - } - - #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] - fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { + Ok(trusted_tx.built_transaction().sign_holder_commitment( + &self.funding_key, + &funding_redeemscript, + self.channel_value_satoshis, + &self, + secp_ctx, + )) + } + + #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))] + fn unsafe_sign_holder_commitment( + &self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1, + ) -> Result { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let funding_redeemscript = + make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey); let trusted_tx = commitment_tx.trust(); - let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx); - let channel_parameters = self.get_channel_parameters(); - let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?; - Ok((sig, htlc_sigs)) - } - - fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1) -> Result { - let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key); + Ok(trusted_tx.built_transaction().sign_holder_commitment( + &self.funding_key, + &funding_redeemscript, + self.channel_value_satoshis, + &self, + secp_ctx, + )) + } + + fn sign_justice_revoked_output( + &self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, + secp_ctx: &Secp256k1, + ) -> Result { + let revocation_key = chan_utils::derive_private_revocation_key( + &secp_ctx, + &per_commitment_key, + &self.revocation_base_key, + ); let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key); - let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint); + let revocation_pubkey = RevocationKey::from_basepoint( + &secp_ctx, + &self.pubkeys().revocation_basepoint, + &per_commitment_point, + ); let witness_script = { - let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint); - chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey) + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let holder_selected_contest_delay = + self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR); + let counterparty_delayedpubkey = DelayedPaymentKey::from_basepoint( + &secp_ctx, + &counterparty_keys.delayed_payment_basepoint, + &per_commitment_point, + ); + chan_utils::get_revokeable_redeemscript( + &revocation_pubkey, + holder_selected_contest_delay, + &counterparty_delayedpubkey, + ) }; let mut sighash_parts = sighash::SighashCache::new(justice_tx); - let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]); - return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self)) + let sighash = hash_to_message!( + &sighash_parts + .segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All) + .unwrap()[..] + ); + return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self)); } - fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result { - let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key); + fn sign_justice_revoked_htlc( + &self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, + htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1, + ) -> Result { + let revocation_key = chan_utils::derive_private_revocation_key( + &secp_ctx, + &per_commitment_key, + &self.revocation_base_key, + ); let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key); - let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint); + let revocation_pubkey = RevocationKey::from_basepoint( + &secp_ctx, + &self.pubkeys().revocation_basepoint, + &per_commitment_point, + ); let witness_script = { - let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint); - let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint); - chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.channel_type_features(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey) + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let counterparty_htlcpubkey = HtlcKey::from_basepoint( + &secp_ctx, + &counterparty_keys.htlc_basepoint, + &per_commitment_point, + ); + let holder_htlcpubkey = HtlcKey::from_basepoint( + &secp_ctx, + &self.pubkeys().htlc_basepoint, + &per_commitment_point, + ); + let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR); + chan_utils::get_htlc_redeemscript_with_explicit_keys( + &htlc, + chan_type, + &counterparty_htlcpubkey, + &holder_htlcpubkey, + &revocation_pubkey, + ) }; let mut sighash_parts = sighash::SighashCache::new(justice_tx); - let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]); - return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self)) + let sighash = hash_to_message!( + &sighash_parts + .segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All) + .unwrap()[..] + ); + return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self)); } fn sign_holder_htlc_transaction( &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor, - secp_ctx: &Secp256k1 + secp_ctx: &Secp256k1, ) -> Result { let witness_script = htlc_descriptor.witness_script(secp_ctx); - let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash( - input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All - ).map_err(|_| ())?; + let sighash = &sighash::SighashCache::new(&*htlc_tx) + .segwit_signature_hash( + input, + &witness_script, + htlc_descriptor.htlc.amount_msat / 1000, + EcdsaSighashType::All, + ) + .map_err(|_| ())?; let our_htlc_private_key = chan_utils::derive_private_key( - &secp_ctx, &htlc_descriptor.per_commitment_point, &self.htlc_base_key + &secp_ctx, + &htlc_descriptor.per_commitment_point, + &self.htlc_base_key, ); - Ok(sign_with_aux_rand(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key, &self)) + let sighash = hash_to_message!(sighash.as_byte_array()); + Ok(sign_with_aux_rand(&secp_ctx, &sighash, &our_htlc_private_key, &self)) } - fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result { - let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key); - let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint); - let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint); - let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint); - let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.channel_type_features(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey); + fn sign_counterparty_htlc_transaction( + &self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, + htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1, + ) -> Result { + let htlc_key = + chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key); + let revocation_pubkey = RevocationKey::from_basepoint( + &secp_ctx, + &self.pubkeys().revocation_basepoint, + &per_commitment_point, + ); + let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR); + let counterparty_htlcpubkey = HtlcKey::from_basepoint( + &secp_ctx, + &counterparty_keys.htlc_basepoint, + &per_commitment_point, + ); + let htlc_basepoint = self.pubkeys().htlc_basepoint; + let htlcpubkey = HtlcKey::from_basepoint(&secp_ctx, &htlc_basepoint, &per_commitment_point); + let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR); + let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys( + &htlc, + chan_type, + &counterparty_htlcpubkey, + &htlcpubkey, + &revocation_pubkey, + ); let mut sighash_parts = sighash::SighashCache::new(htlc_tx); - let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]); + let sighash = hash_to_message!( + &sighash_parts + .segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All) + .unwrap()[..] + ); Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self)) } - fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1) -> Result { + fn sign_closing_transaction( + &self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1, + ) -> Result { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); - Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx)) + let counterparty_funding_key = + &self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey; + let channel_funding_redeemscript = + make_funding_redeemscript(&funding_pubkey, counterparty_funding_key); + Ok(closing_tx.trust().sign( + &self.funding_key, + &channel_funding_redeemscript, + self.channel_value_satoshis, + secp_ctx, + )) } fn sign_holder_anchor_input( &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1, ) -> Result { - let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey); - let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash( - input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All, - ).unwrap(); + let witness_script = + chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey); + let sighash = sighash::SighashCache::new(&*anchor_tx) + .segwit_signature_hash( + input, + &witness_script, + ANCHOR_OUTPUT_VALUE_SATOSHI, + EcdsaSighashType::All, + ) + .unwrap(); Ok(sign_with_aux_rand(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key, &self)) } fn sign_channel_announcement_with_funding_key( - &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1 + &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1, ) -> Result { let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]); Ok(secp_ctx.sign_ecdsa(&msghash, &self.funding_key)) } } +#[cfg(taproot)] +impl TaprootChannelSigner for InMemorySigner { + fn generate_local_nonce_pair( + &self, commitment_number: u64, secp_ctx: &Secp256k1, + ) -> PublicNonce { + todo!() + } + + fn partially_sign_counterparty_commitment( + &self, counterparty_nonce: PublicNonce, commitment_tx: &CommitmentTransaction, + inbound_htlc_preimages: Vec, + outbound_htlc_preimages: Vec, secp_ctx: &Secp256k1, + ) -> Result<(PartialSignatureWithNonce, Vec), ()> { + todo!() + } + + fn finalize_holder_commitment( + &self, commitment_tx: &HolderCommitmentTransaction, + counterparty_partial_signature: PartialSignatureWithNonce, secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn sign_justice_revoked_output( + &self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, + secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn sign_justice_revoked_htlc( + &self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, + htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn sign_holder_htlc_transaction( + &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor, + secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn sign_counterparty_htlc_transaction( + &self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, + htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn partially_sign_closing_transaction( + &self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } + + fn sign_holder_anchor_input( + &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1, + ) -> Result { + todo!() + } +} + const SERIALIZATION_VERSION: u8 = 1; const MIN_SERIALIZATION_VERSION: u8 = 1; @@ -1135,7 +1755,10 @@ impl Writeable for InMemorySigner { } } -impl ReadableArgs for InMemorySigner where ES::Target: EntropySource { +impl ReadableArgs for InMemorySigner +where + ES::Target: EntropySource, +{ fn read(reader: &mut R, entropy_source: ES) -> Result { let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION); @@ -1148,9 +1771,14 @@ impl ReadableArgs for InMemorySigner where ES::Target: EntropySou let counterparty_channel_data = Readable::read(reader)?; let channel_value_satoshis = Readable::read(reader)?; let secp_ctx = Secp256k1::signing_only(); - let holder_channel_pubkeys = - InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key, - &payment_key, &delayed_payment_base_key, &htlc_base_key); + let holder_channel_pubkeys = InMemorySigner::make_holder_keys( + &secp_ctx, + &funding_key, + &revocation_base_key, + &payment_key, + &delayed_payment_base_key, + &htlc_base_key, + ); let keys_id = Readable::read(reader)?; read_tlv_fields!(reader, {}); @@ -1166,8 +1794,7 @@ impl ReadableArgs for InMemorySigner where ES::Target: EntropySou holder_channel_pubkeys, channel_parameters: counterparty_channel_data, channel_keys_id: keys_id, - rand_bytes_unique_start: entropy_source.get_secure_random_bytes(), - rand_bytes_index: AtomicCounter::new(), + entropy_source: RandomBytes::new(entropy_source.get_secure_random_bytes()), }) } } @@ -1190,13 +1817,12 @@ pub struct KeysManager { node_secret: SecretKey, node_id: PublicKey, inbound_payment_key: KeyMaterial, - destination_script: Script, + destination_script: ScriptBuf, shutdown_pubkey: PublicKey, channel_master_key: ExtendedPrivKey, channel_child_index: AtomicUsize, - rand_bytes_unique_start: [u8; 32], - rand_bytes_index: AtomicCounter, + entropy_source: RandomBytes, seed: [u8; 32], starting_time_secs: u64, @@ -1226,23 +1852,42 @@ impl KeysManager { // Note that when we aren't serializing the key, network doesn't matter match ExtendedPrivKey::new_master(Network::Testnet, seed) { Ok(master_key) => { - let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key; + let node_secret = master_key + .ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()) + .expect("Your RNG is busted") + .private_key; let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret); - let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) { + let destination_script = match master_key + .ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) + { Ok(destination_key) => { - let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes()); - Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0) - .push_slice(&wpubkey_hash.into_inner()) + let wpubkey_hash = WPubkeyHash::hash( + &ExtendedPubKey::from_priv(&secp_ctx, &destination_key) + .to_pub() + .to_bytes(), + ); + Builder::new() + .push_opcode(opcodes::all::OP_PUSHBYTES_0) + .push_slice(&wpubkey_hash.to_byte_array()) .into_script() }, Err(_) => panic!("Your RNG is busted"), }; - let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) { - Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key, + let shutdown_pubkey = match master_key + .ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) + { + Ok(shutdown_key) => { + ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key + }, Err(_) => panic!("Your RNG is busted"), }; - let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted"); - let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key; + let channel_master_key = master_key + .ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()) + .expect("Your RNG is busted"); + let inbound_payment_key: SecretKey = master_key + .ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()) + .expect("Your RNG is busted") + .private_key; let mut inbound_pmt_key_bytes = [0; 32]; inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]); @@ -1251,7 +1896,8 @@ impl KeysManager { rand_bytes_engine.input(&starting_time_nanos.to_be_bytes()); rand_bytes_engine.input(seed); rand_bytes_engine.input(b"LDK PRNG Seed"); - let rand_bytes_unique_start = Sha256::from_engine(rand_bytes_engine).into_inner(); + let rand_bytes_unique_start = + Sha256::from_engine(rand_bytes_engine).to_byte_array(); let mut res = KeysManager { secp_ctx, @@ -1265,8 +1911,7 @@ impl KeysManager { channel_master_key, channel_child_index: AtomicUsize::new(0), - rand_bytes_unique_start, - rand_bytes_index: AtomicCounter::new(), + entropy_source: RandomBytes::new(rand_bytes_unique_start), seed: *seed, starting_time_secs, @@ -1286,7 +1931,9 @@ impl KeysManager { } /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters. - pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner { + pub fn derive_channel_keys( + &self, channel_value_satoshis: u64, params: &[u8; 32], + ) -> InMemorySigner { let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap()); let mut unique_start = Sha256::engine(); unique_start.input(params); @@ -1295,18 +1942,23 @@ impl KeysManager { // We only seriously intend to rely on the channel_master_key for true secure // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie // starting_time provided in the constructor) to be unique. - let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, - ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted") - ).expect("Your RNG is busted"); + let child_privkey = self + .channel_master_key + .ckd_priv( + &self.secp_ctx, + ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)) + .expect("key space exhausted"), + ) + .expect("Your RNG is busted"); unique_start.input(&child_privkey.private_key[..]); - let seed = Sha256::from_engine(unique_start).into_inner(); + let seed = Sha256::from_engine(unique_start).to_byte_array(); let commitment_seed = { let mut sha = Sha256::engine(); sha.input(&seed); sha.input(&b"commitment seed"[..]); - Sha256::from_engine(sha).into_inner() + Sha256::from_engine(sha).to_byte_array() }; macro_rules! key_step { ($info: expr, $prev_key: expr) => {{ @@ -1314,8 +1966,9 @@ impl KeysManager { sha.input(&seed); sha.input(&$prev_key[..]); sha.input(&$info[..]); - SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted") - }} + SecretKey::from_slice(&Sha256::from_engine(sha).to_byte_array()) + .expect("SHA-256 is busted") + }}; } let funding_key = key_step!(b"funding key", commitment_seed); let revocation_base_key = key_step!(b"revocation base key", funding_key); @@ -1346,46 +1999,82 @@ impl KeysManager { /// /// 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 sign_spendable_outputs_psbt(&self, descriptors: &[&SpendableOutputDescriptor], mut psbt: PartiallySignedTransaction, secp_ctx: &Secp256k1) -> Result { + pub fn sign_spendable_outputs_psbt( + &self, descriptors: &[&SpendableOutputDescriptor], mut psbt: PartiallySignedTransaction, + secp_ctx: &Secp256k1, + ) -> Result { let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None; for outp in descriptors { + let get_input_idx = |outpoint: &OutPoint| { + psbt.unsigned_tx + .input + .iter() + .position(|i| i.previous_output == outpoint.into_bitcoin_outpoint()) + .ok_or(()) + }; match outp { SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => { - let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?; - if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id { - keys_cache = Some(( - self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id), - descriptor.channel_keys_id)); + let input_idx = get_input_idx(&descriptor.outpoint)?; + if keys_cache.is_none() + || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id + { + let mut signer = self.derive_channel_keys( + descriptor.channel_value_satoshis, + &descriptor.channel_keys_id, + ); + if let Some(channel_params) = + descriptor.channel_transaction_parameters.as_ref() + { + signer.provide_channel_parameters(channel_params); + } + keys_cache = Some((signer, descriptor.channel_keys_id)); } - let witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?); + let witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input( + &psbt.unsigned_tx, + input_idx, + &descriptor, + &secp_ctx, + )?; psbt.inputs[input_idx].final_script_witness = Some(witness); }, SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => { - let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == descriptor.outpoint.into_bitcoin_outpoint()).ok_or(())?; - if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id { + let input_idx = get_input_idx(&descriptor.outpoint)?; + if keys_cache.is_none() + || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id + { keys_cache = Some(( - self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id), - descriptor.channel_keys_id)); + self.derive_channel_keys( + descriptor.channel_value_satoshis, + &descriptor.channel_keys_id, + ), + descriptor.channel_keys_id, + )); } - let witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&psbt.unsigned_tx, input_idx, &descriptor, &secp_ctx)?); + let witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input( + &psbt.unsigned_tx, + input_idx, + &descriptor, + &secp_ctx, + )?; psbt.inputs[input_idx].final_script_witness = Some(witness); }, - SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => { - let input_idx = psbt.unsigned_tx.input.iter().position(|i| i.previous_output == outpoint.into_bitcoin_outpoint()).ok_or(())?; - let derivation_idx = if output.script_pubkey == self.destination_script { - 1 - } else { - 2 - }; + SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output, .. } => { + let input_idx = get_input_idx(outpoint)?; + let derivation_idx = + if output.script_pubkey == self.destination_script { 1 } else { 2 }; let secret = { // Note that when we aren't serializing the key, network doesn't matter match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) { Ok(master_key) => { - match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) { + match master_key.ckd_priv( + &secp_ctx, + ChildNumber::from_hardened_idx(derivation_idx) + .expect("key space exhausted"), + ) { Ok(key) => key, Err(_) => panic!("Your RNG is busted"), } - } + }, Err(_) => panic!("Your rng is busted"), } }; @@ -1393,16 +2082,31 @@ impl KeysManager { if derivation_idx == 2 { assert_eq!(pubkey.inner, self.shutdown_pubkey); } - let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey(); - let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey(); - - if payment_script != output.script_pubkey { return Err(()); }; + let witness_script = + bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey(); + let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet) + .expect("uncompressed key found") + .script_pubkey(); + + if payment_script != output.script_pubkey { + return Err(()); + }; - let sighash = hash_to_message!(&sighash::SighashCache::new(&psbt.unsigned_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]); + let sighash = hash_to_message!( + &sighash::SighashCache::new(&psbt.unsigned_tx) + .segwit_signature_hash( + input_idx, + &witness_script, + output.value, + EcdsaSighashType::All + ) + .unwrap()[..] + ); let sig = sign_with_aux_rand(secp_ctx, &sighash, &secret.private_key, &self); let mut sig_ser = sig.serialize_der().to_vec(); sig_ser.push(EcdsaSighashType::All as u8); - let witness = Witness::from_vec(vec![sig_ser, pubkey.inner.serialize().to_vec()]); + let witness = + Witness::from_slice(&[&sig_ser, &pubkey.inner.serialize().to_vec()]); psbt.inputs[input_idx].final_script_witness = Some(witness); }, } @@ -1410,45 +2114,11 @@ impl KeysManager { 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(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option, secp_ctx: &Secp256k1) -> Result { - 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()); - // 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() + descriptors.len() * 3); - - Ok(spend_tx) - } } impl EntropySource for KeysManager { fn get_secure_random_bytes(&self) -> [u8; 32] { - let index = self.rand_bytes_index.get_increment(); - let mut nonce = [0u8; 16]; - nonce[..8].copy_from_slice(&index.to_be_bytes()); - ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce) + self.entropy_source.get_secure_random_bytes() } } @@ -1456,14 +2126,16 @@ impl NodeSigner for KeysManager { fn get_node_id(&self, recipient: Recipient) -> Result { match recipient { Recipient::Node => Ok(self.node_id.clone()), - Recipient::PhantomNode => Err(()) + Recipient::PhantomNode => Err(()), } } - fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result { + fn ecdh( + &self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>, + ) -> Result { let mut node_secret = match recipient { Recipient::Node => Ok(self.node_secret.clone()), - Recipient::PhantomNode => Err(()) + Recipient::PhantomNode => Err(()), }?; if let Some(tweak) = tweak { node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?; @@ -1475,17 +2147,22 @@ impl NodeSigner for KeysManager { self.inbound_payment_key.clone() } - fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result { + fn sign_invoice( + &self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient, + ) -> Result { let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data); let secret = match recipient { Recipient::Node => Ok(&self.node_secret), - Recipient::PhantomNode => Err(()) + Recipient::PhantomNode => Err(()), }?; - Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret)) + Ok(self.secp_ctx.sign_ecdsa_recoverable( + &hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), + secret, + )) } fn sign_bolt12_invoice_request( - &self, invoice_request: &UnsignedInvoiceRequest + &self, invoice_request: &UnsignedInvoiceRequest, ) -> Result { let message = invoice_request.tagged_hash().as_digest(); let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret); @@ -1494,7 +2171,7 @@ impl NodeSigner for KeysManager { } fn sign_bolt12_invoice( - &self, invoice: &UnsignedBolt12Invoice + &self, invoice: &UnsignedBolt12Invoice, ) -> Result { let message = invoice.tagged_hash().as_digest(); let keys = KeyPair::from_secret_key(&self.secp_ctx, &self.node_secret); @@ -1508,10 +2185,53 @@ impl NodeSigner 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( + &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, + change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, + locktime: Option, secp_ctx: &Secp256k1, + ) -> Result { + 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 Signer = InMemorySigner; + type EcdsaSigner = InMemorySigner; + #[cfg(taproot)] + type TaprootSigner = InMemorySigner; - fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] { + fn generate_channel_keys_id( + &self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128, + ) -> [u8; 32] { let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel); // `child_idx` is the only thing guaranteed to make each channel unique without a restart // (though `user_channel_id` should help, depending on user behavior). If it manages to @@ -1527,15 +2247,17 @@ impl SignerProvider for KeysManager { id } - fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer { + fn derive_channel_signer( + &self, channel_value_satoshis: u64, channel_keys_id: [u8; 32], + ) -> Self::EcdsaSigner { self.derive_channel_keys(channel_value_satoshis, &channel_keys_id) } - fn read_chan_signer(&self, reader: &[u8]) -> Result { + fn read_chan_signer(&self, reader: &[u8]) -> Result { InMemorySigner::read(&mut io::Cursor::new(reader), self) } - fn get_destination_script(&self) -> Result { + fn get_destination_script(&self, _channel_keys_id: [u8; 32]) -> Result { Ok(self.destination_script.clone()) } @@ -1586,7 +2308,9 @@ impl NodeSigner for PhantomKeysManager { } } - fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result { + fn ecdh( + &self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>, + ) -> Result { let mut node_secret = match recipient { Recipient::Node => self.inner.node_secret.clone(), Recipient::PhantomNode => self.phantom_secret.clone(), @@ -1601,23 +2325,28 @@ impl NodeSigner for PhantomKeysManager { self.inbound_payment_key.clone() } - fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result { + fn sign_invoice( + &self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient, + ) -> Result { let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data); let secret = match recipient { Recipient::Node => &self.inner.node_secret, Recipient::PhantomNode => &self.phantom_secret, }; - Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret)) + Ok(self.inner.secp_ctx.sign_ecdsa_recoverable( + &hash_to_message!(&Sha256::hash(&preimage).to_byte_array()), + secret, + )) } fn sign_bolt12_invoice_request( - &self, invoice_request: &UnsignedInvoiceRequest + &self, invoice_request: &UnsignedInvoiceRequest, ) -> Result { self.inner.sign_bolt12_invoice_request(invoice_request) } fn sign_bolt12_invoice( - &self, invoice: &UnsignedBolt12Invoice + &self, invoice: &UnsignedBolt12Invoice, ) -> Result { self.inner.sign_bolt12_invoice(invoice) } @@ -1627,23 +2356,48 @@ impl NodeSigner for PhantomKeysManager { } } +impl OutputSpender for PhantomKeysManager { + /// See [`OutputSpender::spend_spendable_outputs`] and [`KeysManager::spend_spendable_outputs`] + /// for documentation on this method. + fn spend_spendable_outputs( + &self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, + change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32, + locktime: Option, secp_ctx: &Secp256k1, + ) -> Result { + self.inner.spend_spendable_outputs( + descriptors, + outputs, + change_destination_script, + feerate_sat_per_1000_weight, + locktime, + secp_ctx, + ) + } +} + impl SignerProvider for PhantomKeysManager { - type Signer = InMemorySigner; + type EcdsaSigner = InMemorySigner; + #[cfg(taproot)] + type TaprootSigner = InMemorySigner; - fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] { + fn generate_channel_keys_id( + &self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128, + ) -> [u8; 32] { self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id) } - fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer { + fn derive_channel_signer( + &self, channel_value_satoshis: u64, channel_keys_id: [u8; 32], + ) -> Self::EcdsaSigner { self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id) } - fn read_chan_signer(&self, reader: &[u8]) -> Result { + fn read_chan_signer(&self, reader: &[u8]) -> Result { self.inner.read_chan_signer(reader) } - fn get_destination_script(&self) -> Result { - self.inner.get_destination_script() + fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result { + self.inner.get_destination_script(channel_keys_id) } fn get_shutdown_scriptpubkey(&self) -> Result { @@ -1663,9 +2417,15 @@ impl PhantomKeysManager { /// same across restarts, or else inbound payments may fail. /// /// [phantom node payments]: PhantomKeysManager - pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self { + pub fn new( + seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, + cross_node_seed: &[u8; 32], + ) -> Self { let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos); - let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed); + let (inbound_key, phantom_key) = hkdf_extract_expand_twice( + b"LDK Inbound and Phantom Payment Key Expansion", + cross_node_seed, + ); let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap(); let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret); Self { @@ -1676,13 +2436,10 @@ impl PhantomKeysManager { } } - /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method. - pub fn spend_spendable_outputs(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec, change_destination_script: Script, feerate_sat_per_1000_weight: u32, locktime: Option, secp_ctx: &Secp256k1) -> Result { - 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]) -> InMemorySigner { + pub fn derive_channel_keys( + &self, channel_value_satoshis: u64, params: &[u8; 32], + ) -> InMemorySigner { self.inner.derive_channel_keys(channel_value_satoshis, params) } @@ -1698,6 +2455,32 @@ impl PhantomKeysManager { } } +/// An implementation of [`EntropySource`] using ChaCha20. +#[derive(Debug)] +pub struct RandomBytes { + /// Seed from which all randomness produced is derived from. + seed: [u8; 32], + /// Tracks the number of times we've produced randomness to ensure we don't return the same + /// bytes twice. + index: AtomicCounter, +} + +impl RandomBytes { + /// Creates a new instance using the given seed. + pub fn new(seed: [u8; 32]) -> Self { + Self { seed, index: AtomicCounter::new() } + } +} + +impl EntropySource for RandomBytes { + fn get_secure_random_bytes(&self) -> [u8; 32] { + let index = self.index.get_increment(); + let mut nonce = [0u8; 16]; + nonce[..8].copy_from_slice(&index.to_be_bytes()); + ChaCha20::get_single_block(&self.seed, &nonce) + } +} + // Ensure that EcdsaChannelSigner can have a vtable #[test] pub fn dyn_sign() { @@ -1706,13 +2489,13 @@ pub fn dyn_sign() { #[cfg(ldk_bench)] pub mod benches { - use std::sync::{Arc, mpsc}; + use crate::sign::{EntropySource, KeysManager}; + use bitcoin::blockdata::constants::genesis_block; + use bitcoin::Network; use std::sync::mpsc::TryRecvError; + use std::sync::{mpsc, Arc}; use std::thread; use std::time::Duration; - use bitcoin::blockdata::constants::genesis_block; - use bitcoin::Network; - use crate::sign::{EntropySource, KeysManager}; use criterion::Criterion; @@ -1726,24 +2509,23 @@ pub mod benches { for _ in 1..5 { let keys_manager_clone = Arc::clone(&keys_manager); let (stop_sender, stop_receiver) = mpsc::channel(); - let handle = thread::spawn(move || { - loop { - keys_manager_clone.get_secure_random_bytes(); - match stop_receiver.try_recv() { - Ok(_) | Err(TryRecvError::Disconnected) => { - println!("Terminating."); - break; - } - Err(TryRecvError::Empty) => {} - } + let handle = thread::spawn(move || loop { + keys_manager_clone.get_secure_random_bytes(); + match stop_receiver.try_recv() { + Ok(_) | Err(TryRecvError::Disconnected) => { + println!("Terminating."); + break; + }, + Err(TryRecvError::Empty) => {}, } }); handles.push(handle); stops.push(stop_sender); } - bench.bench_function("get_secure_random_bytes", |b| b.iter(|| - keys_manager.get_secure_random_bytes())); + bench.bench_function("get_secure_random_bytes", |b| { + b.iter(|| keys_manager.get_secure_random_bytes()) + }); for stop in stops { let _ = stop.send(());