//! spendable on-chain outputs which the user owns and is responsible for using just as any other
//! on-chain output which is theirs.
-use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut, SigHashType};
+use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut};
use bitcoin::blockdata::script::{Script, Builder};
use bitcoin::blockdata::opcodes;
use bitcoin::network::constants::Network;
use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
use bitcoin::util::bip143;
-use bitcoin_hashes::{Hash, HashEngine};
-use bitcoin_hashes::sha256::HashEngine as Sha256State;
-use bitcoin_hashes::sha256::Hash as Sha256;
-use bitcoin_hashes::sha256d::Hash as Sha256dHash;
-use bitcoin_hashes::hash160::Hash as Hash160;
+use bitcoin::hashes::{Hash, HashEngine};
+use bitcoin::hashes::sha256::HashEngine as Sha256State;
+use bitcoin::hashes::sha256::Hash as Sha256;
+use bitcoin::hashes::sha256d::Hash as Sha256dHash;
+use bitcoin::hashes::hash160::Hash as Hash160;
use secp256k1::key::{SecretKey, PublicKey};
use secp256k1::{Secp256k1, Signature, Signing};
use ln::chan_utils;
use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction};
-use ln::channelmanager::PaymentPreimage;
use ln::msgs;
use std::sync::Arc;
/// Readable/Writable to serialize out a unique reference to this set of keys so
/// that you can serialize the full ChannelManager object.
///
-/// (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly
-/// to the possibility of reentrancy issues by calling the user's code during our deserialization
-/// routine).
-/// TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
-/// ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
+// (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly
+// to the possibility of reentrancy issues by calling the user's code during our deserialization
+// routine).
+// TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
+// ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
pub trait ChannelKeys : Send+Clone {
/// Gets the private key for the anchor tx
fn funding_key<'a>(&'a self) -> &'a SecretKey;
/// Create a signature for a remote commitment transaction and associated HTLC transactions.
///
/// 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)!
+ //
+ // TODO: Document the things someone using this interface should enforce before signing.
+ // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and
+ // making the callee generate it via some util function we expose)!
fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
- /// Create a signature for a local commitment transaction
- ///
- /// 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
- /// TODO: Ensure test-only version doesn't enforce uniqueness of signature when it's enforced in this method
- /// making the callee generate it via some util function we expose)!
- fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>);
-
- /// Create a signature for a local commitment transaction without enforcing one-time signing.
- ///
- /// Testing revocation logic by our test framework needs to sign multiple local commitment
- /// transactions. This unsafe test-only version doesn't enforce one-time signing security
- /// requirement.
+ /// 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.
+ //
+ // TODO: Document the things someone using this interface should enforce before signing.
+ // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and
+ fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+
+ /// Same as sign_local_commitment, but exists only for tests to get access to local commitment
+ /// transactions which will be broadcasted later, after the channel has moved on to a newer
+ /// state. Thus, needs its own method as sign_local_commitment may enforce that we only ever
+ /// get called once.
#[cfg(test)]
- fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>);
+ fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
- /// Signs a transaction created by build_htlc_transaction. If the transaction is an
- /// HTLC-Success transaction, preimage must be set!
- /// TODO: should be merged with sign_local_commitment as a slice of HTLC transactions to sign
- fn sign_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &mut Transaction, their_sig: &Signature, preimage: &Option<PaymentPreimage>, htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey, per_commitment_point: &PublicKey, secp_ctx: &Secp256k1<T>);
+ /// Create a signature for each HTLC transaction spending a local commitment transaction.
+ ///
+ /// Unlike sign_local_commitment, this may be called multiple times with *different*
+ /// local_commitment_tx values. While this will never be called with a revoked
+ /// local_commitment_tx, it is possible that it is called with the second-latest
+ /// local_commitment_tx (only if we haven't yet revoked it) if some watchtower/secondary
+ /// ChannelMonitor decided to broadcast before it had been updated to the latest.
+ ///
+ /// Either an Err should be returned, or a Vec with one entry for each HTLC which exists in
+ /// local_commitment_tx. For those HTLCs which have transaction_output_index set to None
+ /// (implying they were considered dust at the time the commitment transaction was negotiated),
+ /// a corresponding None should be included in the return value. All other positions in the
+ /// return value must contain a signature.
+ fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()>;
/// Create a signature for a (proposed) closing transaction.
///
Ok((commitment_sig, htlc_sigs))
}
- fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) {
- local_commitment_tx.add_local_sig(&self.funding_key, funding_redeemscript, channel_value_satoshis, secp_ctx);
- }
+ 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);
- #[cfg(test)]
- fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) {
- local_commitment_tx.add_local_sig(&self.funding_key, funding_redeemscript, channel_value_satoshis, secp_ctx);
+ Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
- fn sign_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &mut Transaction, their_sig: &Signature, preimage: &Option<PaymentPreimage>, htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey, per_commitment_point: &PublicKey, secp_ctx: &Secp256k1<T>) {
- if htlc_tx.input.len() != 1 { return; }
- if htlc_tx.input[0].witness.len() != 0 { return; }
-
- let htlc_redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, a_htlc_key, b_htlc_key, revocation_key);
-
- if let Ok(our_htlc_key) = chan_utils::derive_private_key(secp_ctx, per_commitment_point, &self.htlc_base_key) {
- let sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
- let local_tx = PublicKey::from_secret_key(&secp_ctx, &our_htlc_key) == *a_htlc_key;
- let our_sig = secp_ctx.sign(&sighash, &our_htlc_key);
-
- htlc_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
+ #[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 channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
- if local_tx { // b, then a
- htlc_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
- htlc_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
- } else {
- htlc_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
- htlc_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
- }
- htlc_tx.input[0].witness[1].push(SigHashType::All as u8);
- htlc_tx.input[0].witness[2].push(SigHashType::All as u8);
-
- if htlc.offered {
- htlc_tx.input[0].witness.push(Vec::new());
- assert!(preimage.is_none());
- } else {
- htlc_tx.input[0].witness.push(preimage.unwrap().0.to_vec());
- }
+ Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
+ }
- htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
- } else { return; }
+ fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
+ local_commitment_tx.get_htlc_sigs(&self.htlc_base_key, local_csv, secp_ctx)
}
fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let child_privkey = self.channel_id_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
sha.input(&child_privkey.private_key.key[..]);
- (Sha256::from_engine(sha).into_inner())
+ Sha256::from_engine(sha).into_inner()
}
}