+// 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.
+
//! 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 util::ser::{Writeable, Writer, Readable};
use ln::chan_utils;
-use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction};
+use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction, PreCalculatedTxCreationKeys};
use ln::msgs;
use std::sync::atomic::{AtomicUsize, Ordering};
///
/// To derive the remote_revocation_pubkey provided here (which is used in the witness
/// script generation), you must pass the remote revocation_basepoint (which appears in the
- /// call to ChannelKeys::set_remote_channel_pubkeys) and the provided per_commitment point
+ /// call to ChannelKeys::on_accept) 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
// 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 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 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<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey;
+ /// 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];
/// Gets the local channel public keys and basepoints
- fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys;
+ fn pubkeys(&self) -> &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.
// 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>), ()>;
+ fn sign_remote_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>), ()>;
/// 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.
+ /// 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
/// (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>>, ()>;
+ fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<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.
/// htlc holds HTLC elements (hash, timelock) if the output being spent is a HTLC output, thus
/// changing the format of the witness script (which is committed to in the BIP 143
/// signatures).
- ///
- /// on_remote_tx_csv is the relative lock-time that that our counterparty would have to set on
- /// their transaction were they to spend the same output. It is included in the witness script
- /// and thus committed to in the BIP 143 signature.
- fn sign_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, on_remote_tx_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+ 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, ()>;
/// Create a signature for a claiming transaction for a HTLC output on a remote commitment
/// transaction, either offered or received.
/// protocol.
fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
- /// Set the remote channel basepoints. This is done immediately on incoming channels
- /// and as soon as the channel is accepted on outgoing channels.
+ /// Set the remote channel basepoints and remote/local to_self_delay.
+ /// This is done immediately on incoming channels and as soon as the channel is accepted on outgoing channels.
+ ///
+ /// We bind local_to_self_delay late here for API convenience.
///
/// Will be called before any signatures are applied.
- fn set_remote_channel_pubkeys(&mut self, channel_points: &ChannelPublicKeys);
+ fn on_accept(&mut self, channel_points: &ChannelPublicKeys, remote_to_self_delay: u16, local_to_self_delay: u16);
}
/// A trait to describe an object which can get user secrets and key material.
fn get_channel_id(&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 {
+ /// Remote public keys and base points
+ remote_channel_pubkeys: ChannelPublicKeys,
+ /// The to_self_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 local transactions.
+ remote_to_self_delay: u16,
+ /// The to_self_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.
+ local_to_self_delay: u16,
+}
+
#[derive(Clone)]
/// A simple implementation of ChannelKeys that just keeps the private keys in memory.
pub struct InMemoryChannelKeys {
pub 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>,
+ /// Remote public keys and remote/local to_self_delay, populated on channel acceptance
+ accepted_channel_data: Option<AcceptedChannelData>,
/// The total value of this channel
channel_value_satoshis: u64,
/// Key derivation parameters
commitment_seed,
channel_value_satoshis,
local_channel_pubkeys,
- remote_channel_pubkeys: None,
+ accepted_channel_data: None,
key_derivation_params,
}
}
}
}
- fn remote_pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { self.remote_channel_pubkeys.as_ref().unwrap() }
+ /// Remote pubkeys.
+ /// Will panic if on_accept wasn't called.
+ pub fn remote_pubkeys(&self) -> &ChannelPublicKeys { &self.accepted_channel_data.as_ref().unwrap().remote_channel_pubkeys }
+
+ /// The to_self_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 local transactions.
+ /// Will panic if on_accept wasn't called.
+ pub fn remote_to_self_delay(&self) -> u16 { self.accepted_channel_data.as_ref().unwrap().remote_to_self_delay }
+
+ /// The to_self_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 local_to_self_delay(&self) -> u16 { self.accepted_channel_data.as_ref().unwrap().local_to_self_delay }
}
impl ChannelKeys for InMemoryChannelKeys {
- 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 get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> 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 pubkeys(&self) -> &ChannelPublicKeys { &self.local_channel_pubkeys }
fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params }
- 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>), ()> {
+ fn sign_remote_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();
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 accepted_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &accepted_data.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 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_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw, accepted_data.local_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) {
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);
+ let remote_channel_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_data.remote_channel_pubkeys.funding_pubkey);
Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
#[cfg(test)]
fn unsafe_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 remote_channel_pubkeys = &self.accepted_channel_data.as_ref().expect("must accept before signing").remote_channel_pubkeys;
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 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>>, ()> {
+ fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
+ let local_csv = self.accepted_channel_data.as_ref().unwrap().remote_to_self_delay;
local_commitment_tx.get_htlc_sigs(&self.htlc_base_key, local_csv, 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>, on_remote_tx_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ 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, ()> {
let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
Ok(revocation_key) => revocation_key,
Err(_) => return Err(())
Ok(remote_delayedpubkey) => remote_delayedpubkey,
Err(_) => return Err(())
};
- chan_utils::get_revokeable_redeemscript(&revocation_pubkey, on_remote_tx_csv, &remote_delayedpubkey)
+ chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.local_to_self_delay(), &remote_delayedpubkey)
};
let sighash_parts = bip143::SighashComponents::new(&justice_tx);
let sighash = hash_to_message!(&sighash_parts.sighash_all(&justice_tx.input[input], &witness_script, amount)[..]);
if closing_tx.input[0].witness.len() != 0 { return Err(()); }
if closing_tx.output.len() > 2 { return Err(()); }
- let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
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 remote_channel_data = self.accepted_channel_data.as_ref().expect("must accept before signing");
+ let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_data.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(&msghash, &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 on_accept(&mut self, channel_pubkeys: &ChannelPublicKeys, remote_to_self_delay: u16, local_to_self_delay: u16) {
+ assert!(self.accepted_channel_data.is_none(), "Already accepted");
+ self.accepted_channel_data = Some(AcceptedChannelData {
+ remote_channel_pubkeys: channel_pubkeys.clone(),
+ remote_to_self_delay,
+ local_to_self_delay,
+ });
}
}
+impl_writeable!(AcceptedChannelData, 0,
+ { remote_channel_pubkeys, remote_to_self_delay, local_to_self_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.remote_channel_pubkeys.write(writer)?;
+ self.accepted_channel_data.write(writer)?;
self.channel_value_satoshis.write(writer)?;
self.key_derivation_params.0.write(writer)?;
self.key_derivation_params.1.write(writer)?;
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 remote_channel_data = Readable::read(reader)?;
let channel_value_satoshis = Readable::read(reader)?;
let secp_ctx = Secp256k1::signing_only();
let local_channel_pubkeys =
commitment_seed,
channel_value_satoshis,
local_channel_pubkeys,
- remote_channel_pubkeys,
+ accepted_channel_data: remote_channel_data,
key_derivation_params: (params_1, params_2),
})
}
projects / rust-lightning / blobdiff