use chain::transaction::OutPoint;
use ln::chan_utils;
-use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, PreCalculatedTxCreationKeys};
+use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
use ln::msgs::UnsignedChannelAnnouncement;
use std::sync::atomic::{AtomicUsize, Ordering};
/// 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)]
+#[derive(Clone, Debug, PartialEq)]
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
///
/// 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 ChannelKeys::on_accept) and the provided per_commitment point
+ /// call to ChannelKeys::ready_channel) 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
// 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 {
+pub trait ChannelKeys : Send+Clone + Writeable {
/// 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 if signing fails or is rejected, the channel will be force-closed.
//
// 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_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &PreCalculatedTxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
+ fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
/// Create a signature for a holder's commitment transaction. This will only ever be called with
- /// the same holder_commitment_tx (or a copy thereof), though there are currently no guarantees
+ /// the same commitment_tx (or a copy thereof), though there are currently no guarantees
/// that it will not be called multiple times.
/// An external signer implementation should check that the commitment has not been revoked.
//
// 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_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+ fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<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.
#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
- fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+ fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
/// Create a signature for each HTLC transaction spending a holder's commitment transaction.
///
/// Unlike sign_holder_commitment, this may be called multiple times with *different*
- /// holder_commitment_tx values. While this will never be called with a revoked
- /// holder_commitment_tx, it is possible that it is called with the second-latest
- /// holder_commitment_tx (only if we haven't yet revoked it) if some watchtower/secondary
+ /// commitment_tx values. While this will never be called with a revoked
+ /// commitment_tx, it is possible that it is called with the second-latest
+ /// 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
- /// holder_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_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()>;
+ /// commitment_tx.
+ fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()>;
/// Create a signature for the given input in a transaction spending an HTLC or commitment
/// transaction output when our counterparty broadcasts an old state.
/// protocol.
fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
- /// Set the counterparty channel basepoints and counterparty_selected/locally_selected_contest_delay.
- /// This is done immediately on incoming channels and as soon as the channel is accepted on outgoing channels.
+ /// Set the counterparty static channel data, including basepoints,
+ /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
+ /// This is done as soon as the funding outpoint is known. Since these are static channel data,
+ /// they MUST NOT be allowed to change to different values once set.
///
- /// We bind locally_selected_contest_delay late here for API convenience.
+ /// channel_parameters.is_populated() MUST be true.
+ ///
+ /// We bind holder_selected_contest_delay late here for API convenience.
///
/// Will be called before any signatures are applied.
- fn on_accept(&mut self, channel_points: &ChannelPublicKeys, counterparty_selected_contest_delay: u16, locally_selected_contest_delay: u16);
+ fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
}
/// A trait to describe an object which can get user secrets and key material.
/// onion packets and for temporary channel IDs. There is no requirement that these be
/// persisted anywhere, though they must be unique across restarts.
fn get_secure_random_bytes(&self) -> [u8; 32];
-}
-#[derive(Clone)]
-/// Holds late-bound channel data.
-/// This data is available after the channel is known to be accepted, either
-/// when receiving an open_channel for an inbound channel or when
-/// receiving accept_channel for an outbound channel.
-struct AcceptedChannelData {
- /// Counterparty public keys and base points
- counterparty_channel_pubkeys: ChannelPublicKeys,
- /// The contest_delay value specified by our counterparty and applied on locally-broadcastable
- /// transactions, ie the amount of time that we have to wait to recover our funds if we
- /// broadcast a transaction. You'll likely want to pass this to the
- /// ln::chan_utils::build*_transaction functions when signing holder's transactions.
- counterparty_selected_contest_delay: u16,
- /// 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
- /// if they broadcast a transaction.
- locally_selected_contest_delay: u16,
+ /// Reads a `ChanKeySigner` for this `KeysInterface` from the given input stream.
+ /// This is only called during deserialization of other objects which contain
+ /// `ChannelKeys`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
+ /// The bytes are exactly those which `<Self::ChanKeySigner 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.
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError>;
}
#[derive(Clone)]
/// A simple implementation of ChannelKeys 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 InMemoryChannelKeys {
/// Private key of anchor tx
pub funding_key: SecretKey,
pub commitment_seed: [u8; 32],
/// Holder public keys and basepoints
pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
- /// Counterparty public keys and counterparty/locally selected_contest_delay, populated on channel acceptance
- accepted_channel_data: Option<AcceptedChannelData>,
+ /// 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
commitment_seed,
channel_value_satoshis,
holder_channel_pubkeys,
- accepted_channel_data: None,
+ channel_parameters: None,
key_derivation_params,
}
}
}
/// Counterparty pubkeys.
- /// Will panic if on_accept wasn't called.
- pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.accepted_channel_data.as_ref().unwrap().counterparty_channel_pubkeys }
+ /// Will panic if ready_channel wasn't called.
+ 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 locally-broadcastable
+ /// 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
- /// broadcast a transaction. You'll likely want to pass this to the
- /// ln::chan_utils::build*_transaction functions when signing holder's transactions.
- /// Will panic if on_accept wasn't called.
- pub fn counterparty_selected_contest_delay(&self) -> u16 { self.accepted_channel_data.as_ref().unwrap().counterparty_selected_contest_delay }
+ /// broadcast a transaction.
+ /// Will panic if ready_channel wasn't called.
+ 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
/// if they broadcast a transaction.
- /// Will panic if on_accept wasn't called.
- pub fn locally_selected_contest_delay(&self) -> u16 { self.accepted_channel_data.as_ref().unwrap().locally_selected_contest_delay }
+ /// Will panic if ready_channel wasn't called.
+ 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 ready_channel wasn't called.
+ pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
+
+ /// Funding outpoint
+ /// Will panic if ready_channel wasn't called.
+ 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
+ /// building transactions.
+ ///
+ /// Will panic if ready_channel wasn't called.
+ pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
+ self.channel_parameters.as_ref().unwrap()
+ }
}
impl ChannelKeys for InMemoryChannelKeys {
fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params }
- fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u32, commitment_tx: &Transaction, pre_keys: &PreCalculatedTxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
- if commitment_tx.input.len() != 1 { return Err(()); }
- let keys = pre_keys.trust_key_derivation();
+ fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> 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 accepted_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &accepted_data.counterparty_channel_pubkeys.funding_pubkey);
-
- let commitment_sighash = hash_to_message!(&bip143::SigHashCache::new(commitment_tx).signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
- 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, accepted_data.locally_selected_contest_delay, htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
- let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
- let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
- 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 htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+ let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
+ let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
+ let holder_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, &holder_htlc_key));
}
Ok((commitment_sig, htlc_sigs))
}
- fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let counterparty_channel_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_channel_data.counterparty_channel_pubkeys.funding_pubkey);
-
- Ok(holder_commitment_tx.get_holder_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
+ let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+ let sig = commitment_tx.trust().built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
+ Ok(sig)
}
#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
- fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let counterparty_channel_pubkeys = &self.accepted_channel_data.as_ref().expect("must accept before signing").counterparty_channel_pubkeys;
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_channel_pubkeys.funding_pubkey);
-
- Ok(holder_commitment_tx.get_holder_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+ Ok(commitment_tx.trust().built_transaction().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
- fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, holder_commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
- let counterparty_selected_contest_delay = self.accepted_channel_data.as_ref().unwrap().counterparty_selected_contest_delay;
- holder_commitment_tx.get_htlc_sigs(&self.htlc_base_key, counterparty_selected_contest_delay, secp_ctx)
+ fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
+ let channel_parameters = self.get_channel_parameters();
+ let trusted_tx = commitment_tx.trust();
+ trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)
}
fn sign_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey,
Err(_) => return Err(())
};
- chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.locally_selected_contest_delay(), &counterparty_delayedpubkey)
+ chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
};
let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
if closing_tx.output.len() > 2 { return Err(()); }
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let counterparty_channel_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_channel_data.counterparty_channel_pubkeys.funding_pubkey);
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
.signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
Ok(secp_ctx.sign(&msghash, &self.funding_key))
}
- fn on_accept(&mut self, channel_pubkeys: &ChannelPublicKeys, counterparty_selected_contest_delay: u16, locally_selected_contest_delay: u16) {
- assert!(self.accepted_channel_data.is_none(), "Already accepted");
- self.accepted_channel_data = Some(AcceptedChannelData {
- counterparty_channel_pubkeys: channel_pubkeys.clone(),
- counterparty_selected_contest_delay,
- locally_selected_contest_delay,
- });
+ fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
+ assert!(self.channel_parameters.is_none(), "Acceptance already noted");
+ assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
+ self.channel_parameters = Some(channel_parameters.clone());
}
}
-impl_writeable!(AcceptedChannelData, 0,
- { counterparty_channel_pubkeys, counterparty_selected_contest_delay, locally_selected_contest_delay });
-
impl Writeable for InMemoryChannelKeys {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
self.funding_key.write(writer)?;
self.delayed_payment_base_key.write(writer)?;
self.htlc_base_key.write(writer)?;
self.commitment_seed.write(writer)?;
- self.accepted_channel_data.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)?;
commitment_seed,
channel_value_satoshis,
holder_channel_pubkeys,
- accepted_channel_data: counterparty_channel_data,
+ channel_parameters: counterparty_channel_data,
key_derivation_params: (params_1, params_2),
})
}
sha.input(b"Unique Secure Random Bytes Salt");
Sha256::from_engine(sha).into_inner()
}
+
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError> {
+ InMemoryChannelKeys::read(&mut std::io::Cursor::new(reader))
+ }
}