use bitcoin_hashes::hash160::Hash as Hash160;
use bitcoin_hashes::sha256d::Hash as Sha256dHash;
-use ln::channelmanager::PaymentHash;
+use ln::channelmanager::{PaymentHash, PaymentPreimage};
use ln::msgs::DecodeError;
use util::ser::{Readable, Writeable, Writer, WriterWriteAdaptor};
use util::byte_utils;
use secp256k1::{Secp256k1, Signature};
use secp256k1;
+use std::{cmp, mem};
+
+const MAX_ALLOC_SIZE: usize = 64*1024;
+
pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
pub(super) const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
/// to broadcast. Eventually this will require a signer which is possibly external, but for now we
/// just pass in the SecretKeys required.
pub struct LocalCommitmentTransaction {
- tx: Transaction
+ tx: Transaction,
+ //TODO: modify Channel methods to integrate HTLC material at LocalCommitmentTransaction generation to drop Option here
+ local_keys: Option<TxCreationKeys>,
+ feerate_per_kw: Option<u64>,
+ per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<Transaction>)>
}
impl LocalCommitmentTransaction {
#[cfg(test)]
input: vec![dummy_input],
output: Vec::new(),
lock_time: 0,
- } }
+ },
+ local_keys: None,
+ feerate_per_kw: None,
+ per_htlc: Vec::new()
+ }
}
/// Generate a new LocalCommitmentTransaction based on a raw commitment transaction,
tx.input[0].witness.push(Vec::new());
}
- Self { tx }
+ Self { tx,
+ local_keys: None,
+ feerate_per_kw: None,
+ per_htlc: Vec::new()
+ }
}
/// Get the txid of the local commitment transaction contained in this
assert!(self.has_local_sig());
&self.tx
}
+
+ /// Set HTLC cache to generate any local HTLC transaction spending one of htlc ouput
+ /// from this local commitment transaction
+ pub(crate) fn set_htlc_cache(&mut self, local_keys: TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<Transaction>)>) {
+ self.local_keys = Some(local_keys);
+ self.feerate_per_kw = Some(feerate_per_kw);
+ self.per_htlc = htlc_outputs;
+ }
+
+ /// Add local signature for a htlc transaction, do nothing if a cached signed transaction is
+ /// already present
+ pub fn add_htlc_sig<T: secp256k1::Signing>(&mut self, htlc_base_key: &SecretKey, htlc_index: u32, preimage: Option<PaymentPreimage>, local_csv: u16, secp_ctx: &Secp256k1<T>) {
+ if self.local_keys.is_none() || self.feerate_per_kw.is_none() { return; }
+ let local_keys = self.local_keys.as_ref().unwrap();
+ let txid = self.txid();
+ for this_htlc in self.per_htlc.iter_mut() {
+ if this_htlc.0.transaction_output_index.unwrap() == htlc_index {
+ if this_htlc.2.is_some() { return; } // we already have a cached htlc transaction at provided index
+ let mut htlc_tx = build_htlc_transaction(&txid, self.feerate_per_kw.unwrap(), local_csv, &this_htlc.0, &local_keys.a_delayed_payment_key, &local_keys.revocation_key);
+ if !this_htlc.0.offered && preimage.is_none() { return; } // if we don't have preimage for HTLC-Success, don't try to generate
+ let htlc_secret = if !this_htlc.0.offered { preimage } else { None }; // if we have a preimage for HTLC-Timeout, don't use it that's likely a duplicate HTLC hash
+ if this_htlc.1.is_none() { return; } // we don't have any remote signature for this htlc
+ if htlc_tx.input.len() != 1 { return; }
+ if htlc_tx.input[0].witness.len() != 0 { return; }
+
+ let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc.0, &local_keys.a_htlc_key, &local_keys.b_htlc_key, &local_keys.revocation_key);
+
+ if let Ok(our_htlc_key) = derive_private_key(secp_ctx, &local_keys.per_commitment_point, htlc_base_key) {
+ let sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, this_htlc.0.amount_msat / 1000)[..]);
+ let our_sig = secp_ctx.sign(&sighash, &our_htlc_key);
+
+ htlc_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
+
+ htlc_tx.input[0].witness.push(this_htlc.1.unwrap().serialize_der().to_vec());
+ htlc_tx.input[0].witness.push(our_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 this_htlc.0.offered {
+ htlc_tx.input[0].witness.push(Vec::new());
+ assert!(htlc_secret.is_none());
+ } else {
+ htlc_tx.input[0].witness.push(htlc_secret.unwrap().0.to_vec());
+ }
+
+ htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
+
+ this_htlc.2 = Some(htlc_tx);
+ } else { return; }
+ }
+ }
+ }
+ /// Expose raw htlc transaction, guarante witness is complete if non-empty
+ pub fn htlc_with_valid_witness(&self, htlc_index: u32) -> &Option<Transaction> {
+ for this_htlc in self.per_htlc.iter() {
+ if this_htlc.0.transaction_output_index.unwrap() == htlc_index {
+ return &this_htlc.2;
+ }
+ }
+ &None
+ }
}
impl PartialEq for LocalCommitmentTransaction {
// We dont care whether we are signed in equality comparison
_ => panic!("local tx must have been well-formed!"),
}
}
+ self.local_keys.write(writer)?;
+ self.feerate_per_kw.write(writer)?;
+ writer.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
+ for &(ref htlc, ref sig, ref htlc_tx) in self.per_htlc.iter() {
+ htlc.write(writer)?;
+ sig.write(writer)?;
+ htlc_tx.write(writer)?;
+ }
Ok(())
}
}
_ => return Err(DecodeError::InvalidValue),
},
};
+ let local_keys = Readable::read(reader)?;
+ let feerate_per_kw = Readable::read(reader)?;
+ let htlcs_count: u64 = Readable::read(reader)?;
+ let mut per_htlc = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / mem::size_of::<(HTLCOutputInCommitment, Option<Signature>, Option<Transaction>)>()));
+ for _ in 0..htlcs_count {
+ let htlc: HTLCOutputInCommitment = Readable::read(reader)?;
+ let sigs = Readable::read(reader)?;
+ let htlc_tx = Readable::read(reader)?;
+ per_htlc.push((htlc, sigs, htlc_tx));
+ }
if tx.input.len() != 1 {
// Ensure tx didn't hit the 0-input ambiguity case.
return Err(DecodeError::InvalidValue);
}
- Ok(Self { tx })
+ Ok(Self {
+ tx,
+ local_keys,
+ feerate_per_kw,
+ per_htlc,
+ })
}
}
projects / rust-lightning / blobdiff