-//! keysinterface provides keys into rust-lightning and defines some useful enums which describe
-//! spendable on-chain outputs which the user owns and is responsible for using just as any other
-//! on-chain output which is theirs.
-
-use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut};
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! Provides keys to LDK and defines some useful objects describing spendable on-chain outputs.
+//!
+//! 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::blockdata::opcodes;
use bitcoin::network::constants::Network;
use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
-use bitcoin::util::bip143;
+use bitcoin::util::sighash;
+use bitcoin::bech32::u5;
use bitcoin::hashes::{Hash, HashEngine};
-use bitcoin::hashes::sha256::HashEngine as Sha256State;
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::sha256d::Hash as Sha256dHash;
use bitcoin::hash_types::WPubkeyHash;
-use bitcoin::secp256k1::key::{SecretKey, PublicKey};
-use bitcoin::secp256k1::{Secp256k1, Signature, Signing};
-use bitcoin::secp256k1;
-
-use util::byte_utils;
-use util::ser::{Writeable, Writer, Readable};
-
-use ln::chan_utils;
-use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction};
-use ln::msgs;
-use ln::channelmanager::PaymentPreimage;
+use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
+use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Signing};
+use bitcoin::secp256k1::ecdh::SharedSecret;
+use bitcoin::secp256k1::ecdsa::RecoverableSignature;
+use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
+
+use crate::util::transaction_utils;
+use crate::util::crypto::{hkdf_extract_expand_twice, sign};
+use crate::util::ser::{Writeable, Writer, Readable};
+#[cfg(anchors)]
+use crate::util::events::HTLCDescriptor;
+use crate::chain::transaction::OutPoint;
+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::msgs::{UnsignedChannelAnnouncement, UnsignedGossipMessage};
+use crate::ln::script::ShutdownScript;
+
+use crate::prelude::*;
+use core::convert::TryInto;
+use core::sync::atomic::{AtomicUsize, Ordering};
+use crate::io::{self, Error};
+use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
+use crate::util::atomic_counter::AtomicCounter;
+use crate::util::chacha20::ChaCha20;
+use crate::util::invoice::construct_invoice_preimage;
+
+/// 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.
+///
+/// (C-not exported) as we just use `[u8; 32]` directly
+#[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
+pub struct KeyMaterial(pub [u8; 32]);
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::io::Error;
-use ln::msgs::DecodeError;
+/// Information about a spendable output to a P2WSH script.
+///
+/// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct DelayedPaymentOutputDescriptor {
+ /// The outpoint which is spendable.
+ pub outpoint: OutPoint,
+ /// Per commitment point to derive the delayed payment key by key holder.
+ pub per_commitment_point: PublicKey,
+ /// The `nSequence` value which must be set in the spending input to satisfy the `OP_CSV` in
+ /// the witness_script.
+ pub to_self_delay: u16,
+ /// The output which is referenced by the given outpoint.
+ 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,
+ /// 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,
+}
+impl DelayedPaymentOutputDescriptor {
+ /// The maximum length a well-formed witness spending one of these should have.
+ // 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;
+}
-/// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
-/// claim at any point in the future) an event is generated which you must track and be able to
-/// spend on-chain. The information needed to do this is provided in this enum, including the
-/// outpoint describing which txid and output index is available, the full output which exists at
-/// that txid/index, and any keys or other information required to sign.
-#[derive(Clone, PartialEq)]
+impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
+ (0, outpoint, required),
+ (2, per_commitment_point, required),
+ (4, to_self_delay, required),
+ (6, output, required),
+ (8, revocation_pubkey, required),
+ (10, channel_keys_id, required),
+ (12, channel_value_satoshis, required),
+});
+
+/// Information about a spendable output to our "payment key".
+///
+/// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct StaticPaymentOutputDescriptor {
+ /// The outpoint which is spendable.
+ pub outpoint: OutPoint,
+ /// The output which is referenced by the given outpoint.
+ pub output: TxOut,
+ /// 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 transactions spends.
+ pub channel_value_satoshis: u64,
+}
+impl StaticPaymentOutputDescriptor {
+ /// The maximum length a well-formed witness spending one of these should have.
+ // 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;
+}
+impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
+ (0, outpoint, required),
+ (2, output, required),
+ (4, channel_keys_id, required),
+ (6, channel_value_satoshis, required),
+});
+
+/// Describes the necessary information to spend a spendable output.
+///
+/// When on-chain outputs are created by LDK (which our counterparty is not able to claim at any
+/// point in the future) a [`SpendableOutputs`] event is generated which you must track and be able
+/// to spend on-chain. The information needed to do this is provided in this enum, including the
+/// outpoint describing which `txid` and output `index` is available, the full output which exists
+/// at that `txid`/`index`, and any keys or other information required to sign.
+///
+/// [`SpendableOutputs`]: crate::util::events::Event::SpendableOutputs
+#[derive(Clone, Debug, PartialEq, Eq)]
pub enum SpendableOutputDescriptor {
- /// An output to a script which was provided via KeysInterface, thus you should already know
- /// how to spend it. No keys are provided as rust-lightning was never given any keys - only the
- /// script_pubkey as it appears in the output.
+ /// An output to a script which was provided via [`SignerProvider`] directly, either from
+ /// [`get_destination_script`] or [`get_shutdown_scriptpubkey`], thus you should already
+ /// know how to spend it. No secret keys are provided as LDK was never given any key.
/// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
/// on-chain using the payment preimage or after it has timed out.
+ ///
+ /// [`get_shutdown_scriptpubkey`]: SignerProvider::get_shutdown_scriptpubkey
+ /// [`get_destination_script`]: SignerProvider::get_shutdown_scriptpubkey
StaticOutput {
- /// The outpoint which is spendable
+ /// The outpoint which is spendable.
outpoint: OutPoint,
/// The output which is referenced by the given outpoint.
output: TxOut,
},
- /// An output to a P2WSH script which can be spent with a single signature after a CSV delay.
+ /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
+ /// delay.
///
/// The witness in the spending input should be:
+ /// ```bitcoin
/// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
+ /// ```
///
- /// Note that the nSequence field in the spending input must be set to to_self_delay
- /// (which means the transaction not being broadcastable until at least to_self_delay
- /// blocks after the outpoint confirms).
+ /// Note that the `nSequence` field in the spending input must be set to
+ /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
+ /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
+ /// the outpoint confirms, see [BIP
+ /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
+ /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
+ /// is reached.
///
/// These are generally the result of a "revocable" output to us, spendable only by us unless
- /// it is an output from us having broadcast an old state (which should never happen).
+ /// it is an output from an old state which we broadcast (which should never happen).
///
- /// WitnessScript may be regenerated by passing the revocation_pubkey, to_self_delay and
- /// delayed_payment_pubkey to chan_utils::get_revokeable_redeemscript.
+ /// 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
+ /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`].
+ ///
+ /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
+ /// used in the witness script generation), you must pass the counterparty
+ /// [`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`].
+ ///
+ /// The witness script which is hashed and included in the output `script_pubkey` may be
+ /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
+ /// as explained above), our delayed payment pubkey (derived as explained above), and the
+ /// [`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:
+ /// ```bitcoin
+ /// <BIP 143 signature> <payment key>
+ /// ```
///
- /// To derive the delayed_payment key corresponding to the channel state, you must pass the
- /// channel's delayed_payment_key and the provided per_commitment_point to
- /// chan_utils::derive_private_key. The resulting key should be used to sign the spending
- /// transaction.
- DynamicOutputP2WSH {
- /// The outpoint which is spendable
- outpoint: OutPoint,
- /// Per commitment point to derive delayed_payment_key by key holder
- per_commitment_point: PublicKey,
- /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
- /// the witness_script.
- to_self_delay: u16,
- /// The output which is referenced by the given outpoint
- output: TxOut,
- /// The channel keys state used to proceed to derivation of signing key. Must
- /// be pass to KeysInterface::derive_channel_keys.
- key_derivation_params: (u64, u64),
- /// The remote_revocation_pubkey used to derive witnessScript
- remote_revocation_pubkey: PublicKey
- },
- // TODO: Note that because key is now static and exactly what is provided by us, we should drop
- // this in favor of StaticOutput:
- /// An output to a P2WPKH, spendable exclusively by the given private key.
- /// The witness in the spending input, is, thus, simply:
- /// <BIP 143 signature generated with the given key> <public key derived from the given key>
/// These are generally the result of our counterparty having broadcast the current state,
/// allowing us to claim the non-HTLC-encumbered outputs immediately.
- DynamicOutputP2WPKH {
- /// The outpoint which is spendable
- outpoint: OutPoint,
- /// The secret key which must be used to sign the spending transaction
- key: SecretKey,
- /// The output which is reference by the given outpoint
- output: TxOut,
- }
+ StaticPaymentOutput(StaticPaymentOutputDescriptor),
}
-impl Writeable for SpendableOutputDescriptor {
- fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
- match self {
- &SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
- 0u8.write(writer)?;
- outpoint.write(writer)?;
- output.write(writer)?;
- },
- &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref per_commitment_point, ref to_self_delay, ref output, ref key_derivation_params, ref remote_revocation_pubkey } => {
- 1u8.write(writer)?;
- outpoint.write(writer)?;
- per_commitment_point.write(writer)?;
- to_self_delay.write(writer)?;
- output.write(writer)?;
- key_derivation_params.0.write(writer)?;
- key_derivation_params.1.write(writer)?;
- remote_revocation_pubkey.write(writer)?;
- },
- &SpendableOutputDescriptor::DynamicOutputP2WPKH { ref outpoint, ref key, ref output } => {
- 2u8.write(writer)?;
- outpoint.write(writer)?;
- key.write(writer)?;
- output.write(writer)?;
- },
- }
- Ok(())
- }
-}
+impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
+ (0, StaticOutput) => {
+ (0, outpoint, required),
+ (2, output, required),
+ },
+;
+ (1, DelayedPaymentOutput),
+ (2, StaticPaymentOutput),
+);
+
+/// 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<secp256k1::All>) -> PublicKey;
-impl Readable for SpendableOutputDescriptor {
- fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
- match Readable::read(reader)? {
- 0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
- outpoint: Readable::read(reader)?,
- output: Readable::read(reader)?,
- }),
- 1u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WSH {
- outpoint: Readable::read(reader)?,
- per_commitment_point: Readable::read(reader)?,
- to_self_delay: Readable::read(reader)?,
- output: Readable::read(reader)?,
- key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?),
- remote_revocation_pubkey: Readable::read(reader)?,
- }),
- 2u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WPKH {
- outpoint: Readable::read(reader)?,
- key: Readable::read(reader)?,
- output: Readable::read(reader)?,
- }),
- _ => Err(DecodeError::InvalidValue),
- }
- }
-}
+ /// Gets the commitment secret for a specific commitment number as part of the revocation process
+ ///
+ /// An external signer implementation should error here if the commitment was already signed
+ /// and should refuse to sign it in the future.
+ ///
+ /// May be called more than once for the same index.
+ ///
+ /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
+ // TODO: return a Result so we can signal a validation error
+ fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
-/// A trait to describe an object which can get user secrets and key material.
-pub trait KeysInterface: Send + Sync {
- /// A type which implements ChannelKeys which will be returned by get_channel_keys.
- type ChanKeySigner : ChannelKeys;
+ /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
+ ///
+ /// This is required in order for the signer to make sure that releasing a commitment
+ /// secret won't leave us without a broadcastable holder transaction.
+ /// 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.
+ fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
+ preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
- /// Get node secret key (aka node_id or network_key)
- fn get_node_secret(&self) -> SecretKey;
- /// Get destination redeemScript to encumber static protocol exit points.
- fn get_destination_script(&self) -> Script;
- /// Get shutdown_pubkey to use as PublicKey at channel closure
- fn get_shutdown_pubkey(&self) -> PublicKey;
- /// Get a new set of ChannelKeys for per-channel secrets. These MUST be unique even if you
- /// restarted with some stale data!
- fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner;
- /// Get a secret and PRNG seed for construting an onion packet
- fn get_onion_rand(&self) -> (SecretKey, [u8; 32]);
- /// Get a unique temporary channel id. Channels will be referred to by this until the funding
- /// transaction is created, at which point they will use the outpoint in the funding
- /// transaction.
- fn get_channel_id(&self) -> [u8; 32];
+ /// Returns the holder's channel public keys and basepoints.
+ fn pubkeys(&self) -> &ChannelPublicKeys;
+
+ /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
+ /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
+ /// [`EcdsaChannelSigner`] object uniquely and lookup or re-derive its keys.
+ fn channel_keys_id(&self) -> [u8; 32];
+
+ /// Set the counterparty static channel data, including basepoints,
+ /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint.
+ ///
+ /// This data is static, and will never change for a channel once set. For a given [`ChannelSigner`]
+ /// instance, LDK will call this method exactly once - either immediately after construction
+ /// (not including if done via [`SignerProvider::read_chan_signer`]) or when the funding
+ /// information has been generated.
+ ///
+ /// channel_parameters.is_populated() MUST be true.
+ fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
}
-/// Set of lightning keys needed to operate a channel as described in BOLT 3.
-///
-/// Signing services could be implemented on a hardware wallet. In this case,
-/// the current ChannelKeys would be a front-end on top of a communication
-/// channel connected to your secure device and lightning key material wouldn't
-/// reside on a hot server. Nevertheless, a this deployment would still need
-/// to trust the ChannelManager to avoid loss of funds as this latest component
-/// could ask to sign commitment transaction with HTLCs paying to attacker pubkeys.
-///
-/// A more secure iteration would be to use hashlock (or payment points) to pair
-/// invoice/incoming HTLCs with outgoing HTLCs to implement a no-trust-ChannelManager
-/// at the price of more state and computation on the hardware wallet side. In the future,
-/// we are looking forward to design such interface.
-///
-/// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
-/// to act, as liveness and breach reply correctness are always going to be hard requirements
-/// of LN security model, orthogonal of key management issues.
-///
-/// If you're implementing a custom signer, you almost certainly want to implement
-/// Readable/Writable to serialize out a unique reference to this set of keys so
-/// that you can serialize the full ChannelManager object.
+/// A trait to sign Lightning channel transactions as described in
+/// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
///
-// (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly
-// to the possibility of reentrancy issues by calling the user's code during our deserialization
-// routine).
-// TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
-// ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
-pub trait ChannelKeys : Send+Clone {
- /// Gets the private key for the anchor tx
- fn funding_key<'a>(&'a self) -> &'a SecretKey;
- /// Gets the local secret key for blinded revocation pubkey
- fn revocation_base_key<'a>(&'a self) -> &'a SecretKey;
- /// Gets the local secret key used in the to_remote output of remote commitment tx (ie the
- /// output to us in transactions our counterparty broadcasts).
- /// Also as part of obscured commitment number.
- fn payment_key<'a>(&'a self) -> &'a SecretKey;
- /// Gets the local secret key used in HTLC-Success/HTLC-Timeout txn and to_local output
- fn delayed_payment_base_key<'a>(&'a self) -> &'a SecretKey;
- /// Gets the local htlc secret key used in commitment tx htlc outputs
- fn htlc_base_key<'a>(&'a self) -> &'a SecretKey;
- /// Gets the commitment seed
- fn commitment_seed<'a>(&'a self) -> &'a [u8; 32];
- /// Gets the local channel public keys and basepoints
- fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys;
- /// Gets arbitrary identifiers describing the set of keys which are provided back to you in
- /// some SpendableOutputDescriptor types. These should be sufficient to identify this
- /// ChannelKeys object uniquely and lookup or re-derive its keys.
- fn key_derivation_params(&self) -> (u64, u64);
-
- /// Create a signature for a remote commitment transaction and associated HTLC transactions.
+/// 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.
- // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and
- // making the callee generate it via some util function we expose)!
- fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
-
- /// Create a signature for a local commitment transaction. This will only ever be called with
- /// the same local_commitment_tx (or a copy thereof), though there are currently no guarantees
- /// that it will not be called multiple times.
- //
+ fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
+ preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
+ ) -> Result<(Signature, Vec<Signature>), ()>;
+ /// 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.
- // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and
- fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
-
- /// Same as sign_local_commitment, but exists only for tests to get access to local commitment
- /// transactions which will be broadcasted later, after the channel has moved on to a newer
- /// state. Thus, needs its own method as sign_local_commitment may enforce that we only ever
- /// get called once.
- #[cfg(test)]
- fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
-
- /// Create a signature for each HTLC transaction spending a local commitment transaction.
- ///
- /// Unlike sign_local_commitment, this may be called multiple times with *different*
- /// local_commitment_tx values. While this will never be called with a revoked
- /// local_commitment_tx, it is possible that it is called with the second-latest
- /// local_commitment_tx (only if we haven't yet revoked it) if some watchtower/secondary
- /// ChannelMonitor decided to broadcast before it had been updated to the latest.
- ///
- /// Either an Err should be returned, or a Vec with one entry for each HTLC which exists in
- /// local_commitment_tx. For those HTLCs which have transaction_output_index set to None
- /// (implying they were considered dust at the time the commitment transaction was negotiated),
- /// a corresponding None should be included in the return value. All other positions in the
- /// return value must contain a signature.
- fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()>;
-
- /// Create a signature for a transaction spending an HTLC or commitment transaction output
- /// when our counterparty broadcast an old state.
- ///
- /// Justice transaction may claim multiples outputs at same time if timelock are similar.
- /// It may be called multiples time for same output(s) if a fee-bump is needed with regards
+ fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction,
+ secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
+ /// 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<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
+ /// 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.
///
- /// Witness_script is a revokable witness script as defined in BOLT3 for `to_local`/HTLC
- /// outputs.
+ /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
///
- /// Input index is a pointer towards outpoint spent, commited by sigs (BIP 143).
+ /// `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<secp256k1::All>
+ ) -> Result<Signature, ()>;
+ /// Create a signature for the given input in a transaction spending a commitment transaction
+ /// HTLC output when our counterparty broadcasts an old state.
///
- /// Amount is value of the output spent by this input, committed by sigs (BIP 143).
+ /// 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.
///
- /// Per_commitment key is revocation secret such as provided by remote party while
- /// revocating detected onchain transaction. It's not a _local_ secret key, therefore
- /// it may cross interfaces, a node compromise won't allow to spend revoked output without
- /// also compromissing revocation key.
- //TODO: dry-up witness_script and pass pubkeys
- fn sign_justice_transaction<T: secp256k1::Signing>(&self, justice_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_key: &SecretKey, revocation_pubkey: &PublicKey, is_htlc: bool, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
-
- /// Create a signature for a claiming transaction for a HTLC output on a remote commitment
+ /// `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<secp256k1::All>) -> Result<Signature, ()>;
+ #[cfg(anchors)]
+ /// 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<secp256k1::All>
+ ) -> Result<Signature, ()>;
+ /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
/// transaction, either offered or received.
///
- /// HTLC transaction may claim multiples offered outputs at same time if we know preimage
- /// for each at detection. It may be called multtiples time for same output(s) if a fee-bump
- /// is needed with regards to an upcoming timelock expiration.
+ /// 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 a offered or received script as defined in BOLT3 for HTLC
+ /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
/// outputs.
///
- /// Input index is a pointer towards outpoint spent, commited by sigs (BIP 143).
- ///
- /// Amount is value of the output spent by this input, committed by sigs (BIP 143).
+ /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
///
- /// Preimage is solution for an offered HTLC haslock. A preimage sets to None hints this
- /// htlc_tx as timing-out funds back to us on a received output.
- //TODO: dry-up witness_script and pass pubkeys
- fn sign_remote_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_point: &PublicKey, preimage: &Option<PaymentPreimage>, secp_ctx: &Secp256k1<T>) -> Result<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<secp256k1::All>) -> Result<Signature, ()>;
/// 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<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
-
- /// Signs a channel announcement message with our funding key, proving it comes from one
- /// of the channel participants.
+ fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
+ secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
+ /// 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<secp256k1::All>,
+ ) -> Result<Signature, ()>;
+ /// 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<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+ fn sign_channel_announcement_with_funding_key(
+ &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
+ ) -> Result<Signature, ()>;
+}
+
+/// 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
+/// the invoice.
+pub enum Recipient {
+ /// The invoice should be signed with the local node secret key.
+ Node,
+ /// The invoice should be signed with the phantom node secret key. This secret key must be the
+ /// same for all nodes participating in the [phantom node payment].
+ ///
+ /// [phantom node payment]: PhantomKeysManager
+ PhantomNode,
+}
+
+/// A trait that describes a source of entropy.
+pub trait EntropySource {
+ /// Gets a unique, cryptographically-secure, random 32-byte value. This method must return a
+ /// different value each time it is called.
+ fn get_secure_random_bytes(&self) -> [u8; 32];
+}
+
+/// A trait that can handle cryptographic operations at the scope level of a node.
+pub trait NodeSigner {
+ /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
+ ///
+ /// If the implementor of this trait supports [phantom node payments], then every node that is
+ /// intended to be included in the phantom invoice route hints must return the same value from
+ /// this method.
+ // This is because LDK avoids storing inbound payment data by encrypting payment data in the
+ // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
+ // nodes, they must share the key that encrypts this payment data.
+ ///
+ /// This method must return the same value each time it is called.
+ ///
+ /// [phantom node payments]: PhantomKeysManager
+ fn get_inbound_payment_key_material(&self) -> KeyMaterial;
+
+ /// Get node id based on the provided [`Recipient`].
+ ///
+ /// This method must return the same value each time it is called with a given [`Recipient`]
+ /// parameter.
+ ///
+ /// Errors if the [`Recipient`] variant is not supported by the implementation.
+ fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
+
+ /// Gets the ECDH shared secret of our node secret and `other_key`, multiplying by `tweak` if
+ /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
+ /// secret, though this is less efficient.
+ ///
+ /// Note that if this fails while attempting to forward an HTLC, LDK will panic. The error
+ /// 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<SharedSecret, ()>;
+
+ /// Sign an invoice.
+ ///
+ /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
+ /// this trait to parse the invoice and make sure they're signing what they expect, rather than
+ /// blindly signing the hash.
+ ///
+ /// The `hrp_bytes` are ASCII bytes, while the `invoice_data` is base32.
+ ///
+ /// 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<RecoverableSignature, ()>;
- /// Set the remote channel basepoints. This is done immediately on incoming channels
- /// and as soon as the channel is accepted on outgoing channels.
+ /// Sign a gossip message.
///
- /// Will be called before any signatures are applied.
- fn set_remote_channel_pubkeys(&mut self, channel_points: &ChannelPublicKeys);
+ /// Note that if this fails, LDK may panic and the message will not be broadcast to the network
+ /// or a possible channel counterparty. If LDK panics, the error should be resolved to allow the
+ /// message to be broadcast, as otherwise it may prevent one from receiving funds over the
+ /// corresponding channel.
+ fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
+}
+
+/// 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;
+
+ /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::Signer`] 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];
+
+ /// Derives the private key material backing a `Signer`.
+ ///
+ /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
+ /// [`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;
+
+ /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream.
+ /// This is only called during deserialization of other objects which contain
+ /// [`WriteableEcdsaChannelSigner`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
+ /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
+ /// contain no versioning scheme. You may wish to include your own version prefix and ensure
+ /// you've read all of the provided bytes to ensure no corruption occurred.
+ ///
+ /// 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
+ /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
+
+ /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
+ ///
+ /// 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) -> Script;
+
+ /// Get a script pubkey which we will send funds to when closing a channel.
+ ///
+ /// 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_shutdown_scriptpubkey(&self) -> ShutdownScript;
}
#[derive(Clone)]
-/// A simple implementation of ChannelKeys that just keeps the private keys in memory.
-pub struct InMemoryChannelKeys {
- /// Private key of anchor tx
- funding_key: SecretKey,
- /// Local secret key for blinded revocation pubkey
- revocation_base_key: SecretKey,
- /// Local secret key used for our balance in remote-broadcasted commitment transactions
- payment_key: SecretKey,
- /// Local secret key used in HTLC tx
- delayed_payment_base_key: SecretKey,
- /// Local htlc secret key used in commitment tx htlc outputs
- htlc_base_key: SecretKey,
- /// Commitment seed
- commitment_seed: [u8; 32],
- /// Local public keys and basepoints
- pub(crate) local_channel_pubkeys: ChannelPublicKeys,
- /// Remote public keys and base points
- pub(crate) remote_channel_pubkeys: Option<ChannelPublicKeys>,
- /// The total value of this channel
+/// 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
+/// a secure external signer.
+pub struct InMemorySigner {
+ /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
+ /// holder's anchor output in a commitment transaction, if one is present.
+ pub funding_key: SecretKey,
+ /// Holder secret key for blinded revocation pubkey.
+ pub revocation_base_key: SecretKey,
+ /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
+ pub payment_key: SecretKey,
+ /// Holder secret key used in an HTLC transaction.
+ pub delayed_payment_base_key: SecretKey,
+ /// Holder HTLC secret key used in commitment transaction HTLC outputs.
+ pub htlc_base_key: SecretKey,
+ /// Commitment seed.
+ pub commitment_seed: [u8; 32],
+ /// Holder public keys and basepoints.
+ pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
+ /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
+ channel_parameters: Option<ChannelTransactionParameters>,
+ /// The total value of this channel.
channel_value_satoshis: u64,
- /// Key derivation parameters
- key_derivation_params: (u64, u64),
+ /// Key derivation parameters.
+ channel_keys_id: [u8; 32],
}
-impl InMemoryChannelKeys {
- /// Create a new InMemoryChannelKeys
+impl InMemorySigner {
+ /// Creates a new [`InMemorySigner`].
pub fn new<C: Signing>(
secp_ctx: &Secp256k1<C>,
funding_key: SecretKey,
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
channel_value_satoshis: u64,
- key_derivation_params: (u64, u64)) -> InMemoryChannelKeys {
- let local_channel_pubkeys =
- InMemoryChannelKeys::make_local_keys(secp_ctx, &funding_key, &revocation_base_key,
- &payment_key, &delayed_payment_base_key,
- &htlc_base_key);
- InMemoryChannelKeys {
+ channel_keys_id: [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);
+ InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
- local_channel_pubkeys,
- remote_channel_pubkeys: None,
- key_derivation_params,
+ holder_channel_pubkeys,
+ channel_parameters: None,
+ channel_keys_id,
}
}
- fn make_local_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
- funding_key: &SecretKey,
- revocation_base_key: &SecretKey,
- payment_key: &SecretKey,
- delayed_payment_base_key: &SecretKey,
- htlc_base_key: &SecretKey) -> ChannelPublicKeys {
+ fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
+ 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),
htlc_basepoint: 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 }
+ /// 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 }
+ /// 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 }
+ /// 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 }
+ /// 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() }
+ /// 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()
+ }
+ /// Returns whether anchors should be used.
+ ///
+ /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
+ pub fn opt_anchors(&self) -> bool {
+ self.get_channel_parameters().opt_anchors.is_some()
+ }
+ /// 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.
+ ///
+ /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
+ /// is not spending the outpoint described by [`descriptor.outpoint`],
+ /// 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<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
+ // 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(()); }
+
+ 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 remotesig = sign(secp_ctx, &sighash, &self.payment_key);
+ let payment_script = bitcoin::Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Bitcoin).unwrap().script_pubkey();
+
+ 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)
+ }
+
+ /// 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.
+ ///
+ /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
+ /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
+ /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
+ /// `script_pubkey` does not match the one we can spend.
+ ///
+ /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
+ /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
+ pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
+ // 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(secp_ctx, &sighash, &delayed_payment_key);
+ 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)
+ }
}
-impl ChannelKeys for InMemoryChannelKeys {
- fn funding_key(&self) -> &SecretKey { &self.funding_key }
- fn revocation_base_key(&self) -> &SecretKey { &self.revocation_base_key }
- fn payment_key(&self) -> &SecretKey { &self.payment_key }
- fn delayed_payment_base_key(&self) -> &SecretKey { &self.delayed_payment_base_key }
- fn htlc_base_key(&self) -> &SecretKey { &self.htlc_base_key }
- fn commitment_seed(&self) -> &[u8; 32] { &self.commitment_seed }
- fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { &self.local_channel_pubkeys }
- fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params }
+impl ChannelSigner for InMemorySigner {
+ fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> 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)
+ }
+
+ fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
+ chan_utils::build_commitment_secret(&self.commitment_seed, idx)
+ }
+
+ fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
+ Ok(())
+ }
+
+ 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);
+ if self.channel_parameters.is_some() {
+ // The channel parameters were already set and they match, return early.
+ return;
+ }
+ assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
+ self.channel_parameters = Some(channel_parameters.clone());
+ }
+}
- fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
- if commitment_tx.input.len() != 1 { return Err(()); }
+impl EcdsaChannelSigner for InMemorySigner {
+ fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
+ let trusted_tx = commitment_tx.trust();
+ let keys = trusted_tx.keys();
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
-
- let commitment_sighash = hash_to_message!(&bip143::SighashComponents::new(&commitment_tx).sighash_all(&commitment_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]);
- let commitment_sig = secp_ctx.sign(&commitment_sighash, &self.funding_key);
-
- let commitment_txid = commitment_tx.txid();
-
- let mut htlc_sigs = Vec::with_capacity(htlcs.len());
- for ref htlc in htlcs {
- if let Some(_) = htlc.transaction_output_index {
- let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw, to_self_delay, htlc, &keys.a_delayed_payment_key, &keys.revocation_key);
- let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
- let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
- let our_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) {
- Ok(s) => s,
- Err(_) => return Err(()),
- };
- htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &our_htlc_key));
- }
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+
+ let built_tx = trusted_tx.built_transaction();
+ let commitment_sig = built_tx.sign(&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, self.opt_anchors(), channel_parameters.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+ let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
+ let htlc_sighashtype = if self.opt_anchors() { 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 sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
-
- Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
+ fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
+ Ok(())
}
- #[cfg(test)]
- fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
+ let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+ let trusted_tx = commitment_tx.trust();
+ let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, 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(), secp_ctx)?;
+ Ok((sig, htlc_sigs))
+ }
- Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
+ #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
+ fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
+ 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 trusted_tx = commitment_tx.trust();
+ let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, 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(), secp_ctx)?;
+ Ok((sig, htlc_sigs))
}
- fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
- local_commitment_tx.get_htlc_sigs(&self.htlc_base_key, local_csv, secp_ctx)
+ fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
+ 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 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 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(secp_ctx, &sighash, &revocation_key))
}
- fn sign_justice_transaction<T: secp256k1::Signing>(&self, justice_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_key: &SecretKey, revocation_pubkey: &PublicKey, is_htlc: bool, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- if let Ok(revocation_key) = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
- let sighash_parts = bip143::SighashComponents::new(&justice_tx);
- let sighash = hash_to_message!(&sighash_parts.sighash_all(&justice_tx.input[input], &witness_script, amount)[..]);
- return Ok(secp_ctx.sign(&sighash, &revocation_key))
- }
- Err(())
+ fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
+ 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 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.opt_anchors(), &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(secp_ctx, &sighash, &revocation_key))
}
- fn sign_remote_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_point: &PublicKey, preimage: &Option<PaymentPreimage>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
- let sighash_parts = bip143::SighashComponents::new(&htlc_tx);
- let sighash = hash_to_message!(&sighash_parts.sighash_all(&htlc_tx.input[input], &witness_script, amount)[..]);
- return Ok(secp_ctx.sign(&sighash, &htlc_key))
- }
- Err(())
+ #[cfg(anchors)]
+ fn sign_holder_htlc_transaction(
+ &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
+ secp_ctx: &Secp256k1<secp256k1::All>
+ ) -> Result<Signature, ()> {
+ let per_commitment_point = self.get_per_commitment_point(
+ htlc_descriptor.per_commitment_number, &secp_ctx
+ );
+ let witness_script = htlc_descriptor.witness_script(&per_commitment_point, 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 our_htlc_private_key = chan_utils::derive_private_key(
+ &secp_ctx, &per_commitment_point, &self.htlc_base_key
+ );
+ Ok(sign(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key))
}
- fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- if closing_tx.input.len() != 1 { return Err(()); }
- if closing_tx.input[0].witness.len() != 0 { return Err(()); }
- if closing_tx.output.len() > 2 { return Err(()); }
+ fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
+ 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.opt_anchors(), &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()[..]);
+ Ok(sign(secp_ctx, &sighash, &htlc_key))
+ }
- let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
+ fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
-
- let sighash = hash_to_message!(&bip143::SighashComponents::new(closing_tx)
- .sighash_all(&closing_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]);
- Ok(secp_ctx.sign(&sighash, &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))
}
- fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
- Ok(secp_ctx.sign(&msghash, &self.funding_key))
+ fn sign_holder_anchor_input(
+ &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
+ ) -> Result<Signature, ()> {
+ 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(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key))
}
- fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) {
- assert!(self.remote_channel_pubkeys.is_none(), "Already set remote channel pubkeys");
- self.remote_channel_pubkeys = Some(channel_pubkeys.clone());
+ fn sign_channel_announcement_with_funding_key(
+ &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
+ ) -> Result<Signature, ()> {
+ let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
+ Ok(sign(secp_ctx, &msghash, &self.funding_key))
}
}
-impl Writeable for InMemoryChannelKeys {
+const SERIALIZATION_VERSION: u8 = 1;
+
+const MIN_SERIALIZATION_VERSION: u8 = 1;
+
+impl WriteableEcdsaChannelSigner for InMemorySigner {}
+
+impl Writeable for InMemorySigner {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+ write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
+
self.funding_key.write(writer)?;
self.revocation_base_key.write(writer)?;
self.payment_key.write(writer)?;
self.delayed_payment_base_key.write(writer)?;
self.htlc_base_key.write(writer)?;
self.commitment_seed.write(writer)?;
- self.remote_channel_pubkeys.write(writer)?;
+ self.channel_parameters.write(writer)?;
self.channel_value_satoshis.write(writer)?;
- self.key_derivation_params.0.write(writer)?;
- self.key_derivation_params.1.write(writer)?;
+ self.channel_keys_id.write(writer)?;
+
+ write_tlv_fields!(writer, {});
Ok(())
}
}
-impl Readable for InMemoryChannelKeys {
- fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+impl Readable for InMemorySigner {
+ fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+ let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
+
let funding_key = Readable::read(reader)?;
let revocation_base_key = Readable::read(reader)?;
let payment_key = Readable::read(reader)?;
let delayed_payment_base_key = Readable::read(reader)?;
let htlc_base_key = Readable::read(reader)?;
let commitment_seed = Readable::read(reader)?;
- let remote_channel_pubkeys = Readable::read(reader)?;
+ let counterparty_channel_data = Readable::read(reader)?;
let channel_value_satoshis = Readable::read(reader)?;
let secp_ctx = Secp256k1::signing_only();
- let local_channel_pubkeys =
- InMemoryChannelKeys::make_local_keys(&secp_ctx, &funding_key, &revocation_base_key,
- &payment_key, &delayed_payment_base_key,
- &htlc_base_key);
- let params_1 = Readable::read(reader)?;
- let params_2 = Readable::read(reader)?;
-
- Ok(InMemoryChannelKeys {
+ 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, {});
+
+ Ok(InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
- local_channel_pubkeys,
- remote_channel_pubkeys,
- key_derivation_params: (params_1, params_2),
+ holder_channel_pubkeys,
+ channel_parameters: counterparty_channel_data,
+ channel_keys_id: keys_id,
})
}
}
-/// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
-/// and derives keys from that.
+/// Simple implementation of [`EntropySource`], [`NodeSigner`], and [`SignerProvider`] that takes a
+/// 32-byte seed for use as a BIP 32 extended key and derives keys from that.
///
-/// Your node_id is seed/0'
-/// ChannelMonitor closes may use seed/1'
-/// Cooperative closes may use seed/2'
+/// Your `node_id` is seed/0'.
+/// Unilateral closes may use seed/1'.
+/// Cooperative closes may use seed/2'.
/// The two close keys may be needed to claim on-chain funds!
+///
+/// This struct cannot be used for nodes that wish to support receiving phantom payments;
+/// [`PhantomKeysManager`] must be used instead.
+///
+/// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
+/// previously issued invoices and attempts to pay previous invoices will fail.
pub struct KeysManager {
- secp_ctx: Secp256k1<secp256k1::SignOnly>,
+ secp_ctx: Secp256k1<secp256k1::All>,
node_secret: SecretKey,
+ node_id: PublicKey,
+ inbound_payment_key: KeyMaterial,
destination_script: Script,
shutdown_pubkey: PublicKey,
channel_master_key: ExtendedPrivKey,
channel_child_index: AtomicUsize,
- session_master_key: ExtendedPrivKey,
- session_child_index: AtomicUsize,
- channel_id_master_key: ExtendedPrivKey,
- channel_id_child_index: AtomicUsize,
+
+ rand_bytes_unique_start: [u8; 32],
+ rand_bytes_index: AtomicCounter,
seed: [u8; 32],
starting_time_secs: u64,
}
impl KeysManager {
- /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your
- /// RNG is busted) this may panic (but more importantly, you will possibly lose funds).
- /// starting_time isn't strictly required to actually be a time, but it must absolutely,
+ /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
+ /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
+ /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
/// without a doubt, be unique to this instance. ie if you start multiple times with the same
- /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to
- /// simply use the current time (with very high precision).
+ /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
+ /// is to simply use the current time (with very high precision).
///
- /// The seed MUST be backed up safely prior to use so that the keys can be re-created, however,
- /// obviously, starting_time should be unique every time you reload the library - it is only
+ /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
+ /// obviously, `starting_time` should be unique every time you reload the library - it is only
/// used to generate new ephemeral key data (which will be stored by the individual channel if
/// necessary).
///
/// Note that the seed is required to recover certain on-chain funds independent of
- /// ChannelMonitor data, though a current copy of ChannelMonitor data is also required for any
- /// channel, and some on-chain during-closing funds.
+ /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
+ /// for any channel, and some on-chain during-closing funds.
///
- /// Note that until the 0.1 release there is no guarantee of backward compatibility between
- /// versions. Once the library is more fully supported, the docs will be updated to include a
- /// detailed description of the guarantee.
- pub fn new(seed: &[u8; 32], network: Network, starting_time_secs: u64, starting_time_nanos: u32) -> KeysManager {
- let secp_ctx = Secp256k1::signing_only();
- match ExtendedPrivKey::new_master(network.clone(), seed) {
+ /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
+ pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
+ let secp_ctx = Secp256k1::new();
+ // 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.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()) {
Ok(destination_key) => {
- let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
+ 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())
- .into_script()
+ .push_slice(&wpubkey_hash.into_inner())
+ .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_private(&secp_ctx, &shutdown_key).public_key.key,
+ 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 session_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
- let channel_id_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted");
-
- KeysManager {
+ 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[..]);
+
+ let mut rand_bytes_engine = Sha256::engine();
+ rand_bytes_engine.input(&starting_time_secs.to_be_bytes());
+ 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 mut res = KeysManager {
secp_ctx,
node_secret,
+ node_id,
+ inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
+
destination_script,
shutdown_pubkey,
+
channel_master_key,
channel_child_index: AtomicUsize::new(0),
- session_master_key,
- session_child_index: AtomicUsize::new(0),
- channel_id_master_key,
- channel_id_child_index: AtomicUsize::new(0),
+
+ rand_bytes_unique_start,
+ rand_bytes_index: AtomicCounter::new(),
seed: *seed,
starting_time_secs,
starting_time_nanos,
- }
+ };
+ let secp_seed = res.get_secure_random_bytes();
+ res.secp_ctx.seeded_randomize(&secp_seed);
+ res
},
Err(_) => panic!("Your rng is busted"),
}
}
- fn derive_unique_start(&self) -> Sha256State {
- let mut unique_start = Sha256::engine();
- unique_start.input(&byte_utils::be64_to_array(self.starting_time_secs));
- unique_start.input(&byte_utils::be32_to_array(self.starting_time_nanos));
- unique_start.input(&self.seed);
- unique_start
- }
- /// Derive an old set of ChannelKeys for per-channel secrets based on a key derivation
- /// parameters.
- /// Key derivation parameters are accessible through a per-channel secrets
- /// ChannelKeys::key_derivation_params and is provided inside DynamicOuputP2WSH in case of
- /// onchain output detection for which a corresponding delayed_payment_key must be derived.
- pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params_1: u64, params_2: u64) -> InMemoryChannelKeys {
- let chan_id = ((params_1 & 0xFFFF_FFFF_0000_0000) >> 32) as u32;
+ /// 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 {
+ let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
let mut unique_start = Sha256::engine();
- unique_start.input(&byte_utils::be64_to_array(params_2));
- unique_start.input(&byte_utils::be32_to_array(params_1 as u32));
+ unique_start.input(params);
unique_start.input(&self.seed);
// 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).expect("key space exhausted")).expect("Your RNG is busted");
- unique_start.input(&child_privkey.private_key.key[..]);
+ 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 delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
- InMemoryChannelKeys::new(
+ InMemorySigner::new(
&self.secp_ctx,
funding_key,
revocation_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
- (params_1, params_2),
+ params.clone(),
)
}
+
+ /// 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.
+ ///
+ /// Returns `Err(())` if the output value is greater than the input value minus required fee,
+ /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
+ /// does not match the one we can spend.
+ ///
+ /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
+ ///
+ /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
+ /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
+ pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
+ let mut input = Vec::new();
+ let mut input_value = 0;
+ let mut witness_weight = 0;
+ let mut output_set = HashSet::with_capacity(descriptors.len());
+ for outp in descriptors {
+ match outp {
+ SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
+ input.push(TxIn {
+ previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: Sequence::ZERO,
+ witness: Witness::new(),
+ });
+ witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+ input_value += descriptor.output.value;
+ if !output_set.insert(descriptor.outpoint) { return Err(()); }
+ },
+ SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
+ input.push(TxIn {
+ previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: Sequence(descriptor.to_self_delay as u32),
+ witness: Witness::new(),
+ });
+ witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+ input_value += descriptor.output.value;
+ if !output_set.insert(descriptor.outpoint) { return Err(()); }
+ },
+ SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
+ input.push(TxIn {
+ previous_output: outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: Sequence::ZERO,
+ witness: Witness::new(),
+ });
+ witness_weight += 1 + 73 + 34;
+ input_value += output.value;
+ if !output_set.insert(*outpoint) { return Err(()); }
+ }
+ }
+ if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
+ }
+ let mut spend_tx = Transaction {
+ version: 2,
+ lock_time: PackedLockTime(0),
+ input,
+ output: outputs,
+ };
+ let expected_max_weight =
+ transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
+
+ let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
+ let mut input_idx = 0;
+ for outp in descriptors {
+ match outp {
+ SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
+ 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));
+ }
+ spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
+ },
+ SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
+ 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));
+ }
+ spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
+ },
+ SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
+ 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")) {
+ Ok(key) => key,
+ Err(_) => panic!("Your RNG is busted"),
+ }
+ }
+ Err(_) => panic!("Your rng is busted"),
+ }
+ };
+ let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
+ 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 sighash = hash_to_message!(&sighash::SighashCache::new(&spend_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
+ let sig = sign(secp_ctx, &sighash, &secret.private_key);
+ let mut sig_ser = sig.serialize_der().to_vec();
+ sig_ser.push(EcdsaSighashType::All as u8);
+ spend_tx.input[input_idx].witness.push(sig_ser);
+ spend_tx.input[input_idx].witness.push(pubkey.inner.serialize().to_vec());
+ },
+ }
+ input_idx += 1;
+ }
+
+ 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)
+ }
}
-impl KeysInterface for KeysManager {
- type ChanKeySigner = InMemoryChannelKeys;
+impl NodeSigner for KeysManager {
+ fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
+ match recipient {
+ Recipient::Node => Ok(self.node_id.clone()),
+ Recipient::PhantomNode => Err(())
+ }
+ }
- fn get_node_secret(&self) -> SecretKey {
- self.node_secret.clone()
+ fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
+ let mut node_secret = match recipient {
+ Recipient::Node => Ok(self.node_secret.clone()),
+ Recipient::PhantomNode => Err(())
+ }?;
+ if let Some(tweak) = tweak {
+ node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
+ }
+ Ok(SharedSecret::new(other_key, &node_secret))
+ }
+
+ fn get_inbound_payment_key_material(&self) -> KeyMaterial {
+ self.inbound_payment_key.clone()
+ }
+
+ fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
+ let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
+ let secret = match recipient {
+ Recipient::Node => Ok(&self.node_secret),
+ Recipient::PhantomNode => Err(())
+ }?;
+ Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret))
+ }
+
+ fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
+ let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
+ Ok(sign(&self.secp_ctx, &msg_hash, &self.node_secret))
+ }
+}
+
+impl SignerProvider for KeysManager {
+ type Signer = InMemorySigner;
+
+ 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
+ // roll over, we may generate duplicate keys for two different channels, which could result
+ // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
+ // doesn't reach `u32::MAX`.
+ assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
+ let mut id = [0; 32];
+ id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
+ id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
+ id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
+ id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
+ id
+ }
+
+ fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
+ self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
+ }
+
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
+ InMemorySigner::read(&mut io::Cursor::new(reader))
}
fn get_destination_script(&self) -> Script {
self.destination_script.clone()
}
- fn get_shutdown_pubkey(&self) -> PublicKey {
- self.shutdown_pubkey.clone()
+ fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
+ ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
+ }
+}
+
+/// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
+/// payments.
+///
+/// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
+/// paid to one of multiple nodes. This works because we encode the invoice route hints such that
+/// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
+/// itself without ever needing to forward to this fake node.
+///
+/// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
+/// provide some fault tolerance, because payers will automatically retry paying other provided
+/// nodes in the case that one node goes down.
+///
+/// Note that multi-path payments are not supported in phantom invoices for security reasons.
+// In the hypothetical case that we did support MPP phantom payments, there would be no way for
+// nodes to know when the full payment has been received (and the preimage can be released) without
+// significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
+// to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
+// is released too early.
+//
+/// Switching between this struct and [`KeysManager`] will invalidate any previously issued
+/// invoices and attempts to pay previous invoices will fail.
+pub struct PhantomKeysManager {
+ inner: KeysManager,
+ inbound_payment_key: KeyMaterial,
+ phantom_secret: SecretKey,
+ phantom_node_id: PublicKey,
+}
+
+impl EntropySource for PhantomKeysManager {
+ fn get_secure_random_bytes(&self) -> [u8; 32] {
+ self.inner.get_secure_random_bytes()
+ }
+}
+
+impl NodeSigner for PhantomKeysManager {
+ fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
+ match recipient {
+ Recipient::Node => self.inner.get_node_id(Recipient::Node),
+ Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
+ }
}
- fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys {
- let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
- let ix_and_nanos: u64 = (child_ix as u64) << 32 | (self.starting_time_nanos as u64);
- self.derive_channel_keys(channel_value_satoshis, ix_and_nanos, self.starting_time_secs)
+ fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
+ let mut node_secret = match recipient {
+ Recipient::Node => self.inner.node_secret.clone(),
+ Recipient::PhantomNode => self.phantom_secret.clone(),
+ };
+ if let Some(tweak) = tweak {
+ node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
+ }
+ Ok(SharedSecret::new(other_key, &node_secret))
}
- fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) {
- let mut sha = self.derive_unique_start();
+ fn get_inbound_payment_key_material(&self) -> KeyMaterial {
+ self.inbound_payment_key.clone()
+ }
- let child_ix = self.session_child_index.fetch_add(1, Ordering::AcqRel);
- let child_privkey = self.session_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
- sha.input(&child_privkey.private_key.key[..]);
+ fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
+ 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))
+ }
- let mut rng_seed = sha.clone();
- // Not exactly the most ideal construction, but the second value will get fed into
- // ChaCha so it is another step harder to break.
- rng_seed.input(b"RNG Seed Salt");
- sha.input(b"Session Key Salt");
- (SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("Your RNG is busted"),
- Sha256::from_engine(rng_seed).into_inner())
+ fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
+ self.inner.sign_gossip_message(msg)
}
+}
- fn get_channel_id(&self) -> [u8; 32] {
- let mut sha = self.derive_unique_start();
+impl SignerProvider for PhantomKeysManager {
+ type Signer = InMemorySigner;
- let child_ix = self.channel_id_child_index.fetch_add(1, Ordering::AcqRel);
- let child_privkey = self.channel_id_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
- sha.input(&child_privkey.private_key.key[..]);
+ 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)
+ }
- Sha256::from_engine(sha).into_inner()
+ fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
+ self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
}
+
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
+ self.inner.read_chan_signer(reader)
+ }
+
+ fn get_destination_script(&self) -> Script {
+ self.inner.get_destination_script()
+ }
+
+ fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
+ self.inner.get_shutdown_scriptpubkey()
+ }
+}
+
+impl PhantomKeysManager {
+ /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
+ /// that is shared across all nodes that intend to participate in [phantom node payments]
+ /// together.
+ ///
+ /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
+ /// `starting_time_nanos`.
+ ///
+ /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
+ /// 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 {
+ 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 phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
+ let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
+ Self {
+ inner,
+ inbound_payment_key: KeyMaterial(inbound_key),
+ phantom_secret,
+ phantom_node_id,
+ }
+ }
+
+ /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
+ pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
+ self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, 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 {
+ self.inner.derive_channel_keys(channel_value_satoshis, params)
+ }
+}
+
+// Ensure that EcdsaChannelSigner can have a vtable
+#[test]
+pub fn dyn_sign() {
+ let _signer: Box<dyn EcdsaChannelSigner>;
+}
+
+#[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
+mod benches {
+ use std::sync::{Arc, mpsc};
+ use std::sync::mpsc::TryRecvError;
+ use std::thread;
+ use std::time::Duration;
+ use bitcoin::blockdata::constants::genesis_block;
+ use bitcoin::Network;
+ use crate::chain::keysinterface::{EntropySource, KeysManager};
+
+ use test::Bencher;
+
+ #[bench]
+ fn bench_get_secure_random_bytes(bench: &mut Bencher) {
+ let seed = [0u8; 32];
+ let now = Duration::from_secs(genesis_block(Network::Testnet).header.time as u64);
+ let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_micros()));
+
+ let mut handles = Vec::new();
+ let mut stops = Vec::new();
+ 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) => {}
+ }
+ }
+ });
+ handles.push(handle);
+ stops.push(stop_sender);
+ }
+
+ bench.iter(|| {
+ for _ in 1..100 {
+ keys_manager.get_secure_random_bytes();
+ }
+ });
+
+ for stop in stops {
+ let _ = stop.send(());
+ }
+ for handle in handles {
+ handle.join().unwrap();
+ }
+ }
+
}