// You may not use this file except in accordance with one or both of these
// licenses.
-//! 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.
+//! 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};
/// 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
+///
+/// (C-not exported) as we just use `[u8; 32]` directly
#[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
pub struct KeyMaterial(pub [u8; 32]);
-/// Information about a spendable output to a P2WSH script. See
-/// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
+/// 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
+ /// The outpoint which is spendable.
pub outpoint: OutPoint,
- /// Per commitment point to derive delayed_payment_key by key holder
+ /// 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 `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
+ /// 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
- /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
- /// the channel to spend the output.
+ /// Arbitrary identification information returned by a call to [`BaseSign::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,
(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.
+/// 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
+ /// The outpoint which is spendable.
pub outpoint: OutPoint,
- /// The output which is referenced by the given outpoint
+ /// The output which is referenced by the given outpoint.
pub output: TxOut,
- /// Arbitrary identification information returned by a call to
- /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
- /// the channel to spend the output.
+ /// Arbitrary identification information returned by a call to [`BaseSign::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,
(6, channel_value_satoshis, required),
});
-/// 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.
+/// 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 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 rust-lightning was never given any key.
+ /// An output to a script which was provided via [`KeysInterface`] 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`]: KeysInterface::get_shutdown_scriptpubkey
+ /// [`get_destination_script`]: KeysInterface::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 is not 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 an old state which we broadcast (which should never happen).
///
- /// To derive the delayed_payment key which is used to sign for this input, you must pass the
- /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in
- /// Sign::pubkeys().delayed_payment_basepoint) and the provided 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 delayed_payment_basepoint which appears in
- /// Sign::pubkeys().
- ///
- /// To derive the revocation_pubkey provided here (which is used in the witness
- /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
- /// call to Sign::provide_channel_parameters) and the provided 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 revocation_pubkey (derived as above), our delayed_payment pubkey
- /// (derived as above), and the to_self_delay contained here 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 [`BaseSign::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 [`BaseSign::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
+ /// [`BaseSign::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 (ie the private key which
- /// corresponds to the public key in Sign::pubkeys().payment_point).
- /// The witness in the spending input, is, thus, simply:
+ /// An output to a P2WPKH, spendable exclusively by our payment key (i.e., the private key
+ /// which corresponds to the `payment_point` in [`BaseSign::pubkeys`]). The witness
+ /// in the spending input is, thus, simply:
+ /// ```bitcoin
/// <BIP 143 signature> <payment key>
+ /// ```
///
/// These are generally the result of our counterparty having broadcast the current state,
/// allowing us to claim the non-HTLC-encumbered outputs immediately.
(2, StaticPaymentOutput),
);
-/// A trait to sign lightning channel transactions as described in BOLT 3.
-///
-/// Signing services could be implemented on a hardware wallet. In this case,
-/// the current Sign 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 trait to sign Lightning channel transactions as described in
+/// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
///
-/// 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.
-// TODO: We should remove Clone by instead requesting a new Sign copy when we create
-// ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
+/// 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 BaseSign {
/// Gets the per-commitment point for a specific commitment number
///
- /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
+ /// 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;
/// Gets the commitment secret for a specific commitment number as part of the revocation process
///
///
/// May be called more than once for the same index.
///
- /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
+ /// 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];
/// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
/// 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: all the relevant preimages will be provided, but there may also be additional
+ /// 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<(), ()>;
- /// Gets the holder's channel public keys and basepoints
+ fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
+ preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
+ /// Returns the holder's channel public keys and basepoints.
fn pubkeys(&self) -> &ChannelPublicKeys;
- /// Gets 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
- /// Sign object uniquely and lookup or re-derive its keys.
+ /// 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
+ /// [`BaseSign`] object uniquely and lookup or re-derive its keys.
fn channel_keys_id(&self) -> [u8; 32];
-
/// 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.
/// 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: all the relevant preimages will be provided, but there may also be additional
+ /// Note that all the relevant preimages will be provided, but there may also be additional
/// irrelevant or duplicate preimages.
//
// TODO: Document the things someone using this interface should enforce before signing.
- fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
+ 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<(), ()>;
-
- /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions.
- /// This will only ever be called with a non-revoked commitment_tx. This will be called with the
- /// latest commitment_tx when we initiate a force-close.
- /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are
- /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to
- /// the latest.
+ /// 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.
///
- /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case.
- //
+ /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
// TODO: Document the things someone using this interface should enforce before signing.
- // TODO: Key derivation failure should panic rather than Err
- fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
-
- /// Same as sign_holder_commitment, 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 may enforce that we only ever
- /// get called once.
+ 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>), ()>;
-
+ 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.
///
///
/// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
///
- /// per_commitment_key is revocation secret which was provided by our counterparty when they
+ /// `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
+ /// 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, ()>;
-
+ 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.
///
/// It may be called multiple times for same output(s) if a fee-bump is needed with regards
/// to an upcoming timelock expiration.
///
- /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
+ /// `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
+ /// `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
+ /// `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, ()>;
-
+ 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
+ /// `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>
+ 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.
///
/// 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.
///
- /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
+ /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
///
- /// Per_commitment_point is the dynamic point corresponding to the channel state
+ /// `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, ()>;
-
+ 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(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
-
+ 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 and our node secret key (aka
/// node_id or network_key), proving it comes from one of the channel participants.
///
/// protocol.
fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>)
-> Result<(Signature, Signature), ()>;
-
/// Set the counterparty static channel data, including basepoints,
- /// counterparty_selected/holder_selected_contest_delay and funding outpoint. Since these are
- /// static channel data, they MUST NOT be allowed to change to different values once set, as LDK
- /// may call this method more than once.
+ /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint. Since these
+ /// are static channel data, they MUST NOT be allowed to change to different values once set,
+ /// as LDK may call this method more than once.
///
/// channel_parameters.is_populated() MUST be true.
fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
///
/// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
/// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
-pub trait Sign: BaseSign + Writeable {
-}
+pub trait Sign: BaseSign + Writeable {}
-/// Specifies the recipient of an invoice, to indicate to [`KeysInterface::sign_invoice`] what node
-/// secret key should be used to sign the invoice.
+/// Specifies the recipient of an invoice.
+///
+/// This indicates to [`KeysInterface::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,
/// A trait to describe an object which can get user secrets and key material.
pub trait KeysInterface {
- /// A type which implements Sign which will be returned by derive_channel_signer.
+ /// A type which implements [`Sign`] which will be returned by [`Self::derive_channel_signer`].
type Signer : Sign;
-
/// Get node secret key based on the provided [`Recipient`].
///
- /// The node_id/network_key is the public key that corresponds to this secret key.
+ /// The `node_id`/`network_key` is the public key that corresponds to this secret key.
///
- /// This method must return the same value each time it is called with a given `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.
+ /// Errors if the [`Recipient`] variant is not supported by the implementation.
fn get_node_secret(&self, recipient: Recipient) -> Result<SecretKey, ()>;
/// Get node id based on the provided [`Recipient`]. This public key corresponds to the secret in
/// [`get_node_secret`].
///
- /// This method must return the same value each time it is called with a given `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.
+ /// Errors if the [`Recipient`] variant is not supported by the implementation.
///
- /// [`get_node_secret`]: KeysInterface::get_node_secret
+ /// [`get_node_secret`]: Self::get_node_secret
fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
let secp_ctx = Secp256k1::signing_only();
Ok(PublicKey::from_secret_key(&secp_ctx, &self.get_node_secret(recipient)?))
/// one is provided. Note that this tweak can be applied to `other_key` instead of our node
/// secret, though this is less efficient.
///
- /// Errors if the `Recipient` variant is not supported by the implementation.
+ /// Errors if the [`Recipient`] variant is not supported by the implementation.
///
/// [`node secret`]: Self::get_node_secret
fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
/// 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;
- /// Generates a unique `channel_keys_id` that can be used to obtain a `Signer` through
- /// [`KeysInterface::derive_channel_signer`]. The `user_channel_id` is provided to allow
- /// implementations of `KeysInterface` to maintain a mapping between it and the generated
- /// `channel_keys_id`.
+ /// Get a new set of [`Sign`] for per-channel secrets. These MUST be unique even if you
+ /// restarted with some stale data!
///
/// 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];
///
/// This method must return a different value each time it is called.
fn get_secure_random_bytes(&self) -> [u8; 32];
-
- /// Reads a `Signer` for this `KeysInterface` from the given input stream.
+ /// Reads a [`Signer`] for this [`KeysInterface`] from the given input stream.
/// This is only called during deserialization of other objects which contain
- /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
+ /// [`Sign`]-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>;
-
/// 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 is ascii bytes, while the invoice data is base32.
+ /// The `hrp` is ASCII bytes, while the invoice data is base32-encoded.
///
/// The secret key used to sign the invoice is dependent on the [`Recipient`].
///
- /// Errors if the `Recipient` variant is not supported by the implementation.
+ /// Errors if the [`Recipient`] variant is not supported by the implementation.
fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], receipient: Recipient) -> Result<RecoverableSignature, ()>;
-
/// 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 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.
///
}
#[derive(Clone)]
-/// A simple implementation of Sign that just keeps the private keys in memory.
+/// A simple implementation of [`Sign`] 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 {
- /// Private key of anchor tx
+ /// 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
+ /// Holder secret key for blinded revocation pubkey.
pub revocation_base_key: SecretKey,
- /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions
+ /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
pub payment_key: SecretKey,
- /// Holder secret key used in HTLC tx
+ /// Holder secret key used in an HTLC transaction.
pub delayed_payment_base_key: SecretKey,
- /// Holder htlc secret key used in commitment tx htlc outputs
+ /// Holder HTLC secret key used in commitment transaction HTLC outputs.
pub htlc_base_key: SecretKey,
- /// Commitment seed
+ /// Commitment seed.
pub commitment_seed: [u8; 32],
- /// Holder public keys and basepoints
+ /// Holder public keys and basepoints.
pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
- /// Private key of our node secret, used for signing channel announcements
+ /// Private key of our node secret, used for signing channel announcements.
node_secret: SecretKey,
- /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance
+ /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
channel_parameters: Option<ChannelTransactionParameters>,
- /// The total value of this channel
+ /// The total value of this channel.
channel_value_satoshis: u64,
- /// Key derivation parameters
+ /// Key derivation parameters.
channel_keys_id: [u8; 32],
}
impl InMemorySigner {
- /// Create a new InMemorySigner
+ /// Creates a new [`InMemorySigner`].
pub fn new<C: Signing>(
secp_ctx: &Secp256k1<C>,
node_secret: SecretKey,
) -> 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);
+ &payment_key, &delayed_payment_base_key,
+ &htlc_base_key);
InMemorySigner {
funding_key,
revocation_base_key,
}
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 {
+ 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),
}
}
- /// Counterparty pubkeys.
- /// Will panic if provide_channel_parameters wasn't called.
+ /// Returns the counterparty's pubkeys.
+ ///
+ /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
-
- /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
- /// transactions, ie the amount of time that we have to wait to recover our funds if we
+ /// 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 provide_channel_parameters wasn't called.
+ ///
+ /// Will panic if [`BaseSign::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 }
-
- /// The contest_delay value specified by us and applied on transactions broadcastable
- /// by our counterparty, ie the amount of time that they have to wait to recover their funds
+ /// 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 provide_channel_parameters wasn't called.
+ ///
+ /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
-
- /// Whether the holder is the initiator
- /// Will panic if provide_channel_parameters wasn't called.
+ /// Returns whether the holder is the initiator.
+ ///
+ /// Will panic if [`BaseSign::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 provide_channel_parameters wasn't called.
+ ///
+ /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
-
- /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
+ /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
/// building transactions.
///
- /// Will panic if provide_channel_parameters wasn't called.
+ /// Will panic if [`BaseSign::provide_channel_parameters`] has not been called before.
pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
self.channel_parameters.as_ref().unwrap()
}
-
- /// Whether anchors should be used.
- /// Will panic if provide_channel_parameters wasn't called.
+ /// Returns whether anchors should be used.
+ ///
+ /// Will panic if [`BaseSign::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.
+ /// 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.
///
- /// Returns an Err 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
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(()); }
+ if payment_script != descriptor.output.script_pubkey { return Err(()); }
let mut witness = Vec::with_capacity(2);
witness.push(remotesig.serialize_der().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.
+ /// 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 Err 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.
+ /// 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
}
fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
+
fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
}
const SERIALIZATION_VERSION: u8 = 1;
+
const MIN_SERIALIZATION_VERSION: u8 = 1;
impl Sign for InMemorySigner {}
let secp_ctx = Secp256k1::signing_only();
let holder_channel_pubkeys =
InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
- &payment_key, &delayed_payment_base_key,
- &htlc_base_key);
+ &payment_key, &delayed_payment_base_key, &htlc_base_key);
let keys_id = Readable::read(reader)?;
read_tlv_fields!(reader, {});
}
}
-/// Simple KeysInterface implementor that takes a 32-byte seed for use as a BIP 32 extended key
-/// and derives keys from that.
+/// Simple [`KeysInterface`] implementation 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;
}
impl KeysManager {
- /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg 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,
+ /// 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.
+ /// [`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
Ok(destination_key) => {
let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
- .push_slice(&wpubkey_hash.into_inner())
- .into_script()
+ .push_slice(&wpubkey_hash.into_inner())
+ .into_script()
},
Err(_) => panic!("Your RNG is busted"),
};
Err(_) => panic!("Your rng is busted"),
}
}
- /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
+ /// Derive an old [`Sign`] 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();
)
}
- /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
+ /// 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.
///
///
/// 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.
+ /// 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;
/// 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.
+// 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.
}
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.
+ /// 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`.
projects / rust-lightning / commitdiff