use chain::transaction::OutPoint;
use ln::chan_utils;
-use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
+use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
use ln::msgs::UnsignedChannelAnnouncement;
use ln::script::ShutdownScript;
/// 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.
+ ///
+ /// This is required in order for the signer to make sure that releasing a commitment
+ /// secret won't leave us without a broadcastable holder transaction.
+ /// Policy checks should be implemented in this function, including checking the amount
+ /// sent to us and checking the HTLCs.
+ fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction) -> Result<(), ()>;
/// Gets 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
/// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
///
/// Note that if signing fails or is rejected, the channel will be force-closed.
+ ///
+ /// Policy checks should be implemented in this function, including checking the amount
+ /// sent to us and checking the HTLCs.
//
// TODO: Document the things someone using this interface should enforce before signing.
fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, 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
///
/// 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: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
+ fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
/// Signs a channel announcement message with our funding key, proving it comes from one
/// of the channel participants.
self.channel_parameters.as_ref().unwrap()
}
+ /// Whether anchors should be used.
+ /// Will panic if ready_channel wasn't called.
+ 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.
///
chan_utils::build_commitment_secret(&self.commitment_seed, idx)
}
+ fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction) -> Result<(), ()> {
+ Ok(())
+ }
+
fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
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_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+ let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &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 = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
Ok((commitment_sig, htlc_sigs))
}
+ fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
+ Ok(())
+ }
+
fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let witness_script = {
let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
- chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
+ chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
};
let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
- chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
+ chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
} else { return Err(()) }
} else { return Err(()) }
} else { return Err(()) };
Err(())
}
- fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
- if closing_tx.input.len() != 1 { return Err(()); }
- if closing_tx.input[0].witness.len() != 0 { return Err(()); }
- if closing_tx.output.len() > 2 { return Err(()); }
-
+ fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &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(&sighash, &self.funding_key))
+ Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
input,
output: outputs,
};
- transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
+ let expected_max_weight =
+ transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
let mut input_idx = 0;
}
input_idx += 1;
}
+
+ debug_assert!(expected_max_weight >= spend_tx.get_weight());
+ // Note that witnesses with a signature vary somewhat in size, so allow
+ // `expected_max_weight` to overshoot by up to 3 bytes per input.
+ debug_assert!(expected_max_weight <= spend_tx.get_weight() + descriptors.len() * 3);
+
Ok(spend_tx)
}
}