use bitcoin::blockdata::script::{Script,Builder};
use bitcoin::blockdata::opcodes;
-use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction};
+use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, SigHashType};
+use bitcoin::consensus::encode::{self, Decodable, Encodable};
+use bitcoin::util::bip143;
use bitcoin_hashes::{Hash, HashEngine};
use bitcoin_hashes::sha256::Hash as Sha256;
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 secp256k1::key::{PublicKey,SecretKey};
-use secp256k1::Secp256k1;
+use secp256k1::key::{SecretKey,PublicKey};
+use secp256k1::{Secp256k1, Signature};
use secp256k1;
pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
base_point.combine(&hashkey)
}
-/// Derives a revocation key from its constituent parts
+/// Derives a revocation key from its constituent parts.
+/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
+/// generated (ie our own).
pub(super) fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, revocation_base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
let revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &revocation_base_secret);
let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
output: txouts,
}
}
+
+/// Signs a transaction created by build_htlc_transaction. If the transaction is an
+/// HTLC-Success transaction (ie htlc.offered is false), preimage must be set!
+pub(crate) fn sign_htlc_transaction<T: secp256k1::Signing>(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, htlc_base_key: &SecretKey, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Script), ()> {
+ if tx.input.len() != 1 { return Err(()); }
+ if tx.input[0].witness.len() != 0 { return Err(()); }
+
+ let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&htlc, a_htlc_key, b_htlc_key, revocation_key);
+
+ let our_htlc_key = derive_private_key(secp_ctx, per_commitment_point, htlc_base_key).map_err(|_| ())?;
+ let sighash = hash_to_message!(&bip143::SighashComponents::new(&tx).sighash_all(&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);
+
+ tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
+
+ if local_tx { // b, then a
+ tx.input[0].witness.push(their_sig.serialize_der().to_vec());
+ tx.input[0].witness.push(our_sig.serialize_der().to_vec());
+ } else {
+ tx.input[0].witness.push(our_sig.serialize_der().to_vec());
+ tx.input[0].witness.push(their_sig.serialize_der().to_vec());
+ }
+ tx.input[0].witness[1].push(SigHashType::All as u8);
+ tx.input[0].witness[2].push(SigHashType::All as u8);
+
+ if htlc.offered {
+ tx.input[0].witness.push(Vec::new());
+ assert!(preimage.is_none());
+ } else {
+ tx.input[0].witness.push(preimage.unwrap().0.to_vec());
+ }
+
+ tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
+
+ Ok((our_sig, htlc_redeemscript))
+}
+
+#[derive(Clone)]
+/// We use this to track local commitment transactions and put off signing them until we are ready
+/// to broadcast. Eventually this will require a signer which is possibly external, but for now we
+/// just pass in the SecretKeys required.
+pub(crate) struct LocalCommitmentTransaction {
+ tx: Transaction
+}
+impl LocalCommitmentTransaction {
+ #[cfg(test)]
+ pub fn dummy() -> Self {
+ Self { tx: Transaction {
+ version: 2,
+ input: Vec::new(),
+ output: Vec::new(),
+ lock_time: 0,
+ } }
+ }
+
+ pub fn new_missing_local_sig(mut tx: Transaction, their_sig: &Signature, our_funding_key: &PublicKey, their_funding_key: &PublicKey) -> LocalCommitmentTransaction {
+ if tx.input.len() != 1 { panic!("Tried to store a commitment transaction that had input count != 1!"); }
+ if tx.input[0].witness.len() != 0 { panic!("Tried to store a signed commitment transaction?"); }
+
+ tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
+
+ if our_funding_key.serialize()[..] < their_funding_key.serialize()[..] {
+ tx.input[0].witness.push(Vec::new());
+ tx.input[0].witness.push(their_sig.serialize_der().to_vec());
+ tx.input[0].witness[2].push(SigHashType::All as u8);
+ } else {
+ tx.input[0].witness.push(their_sig.serialize_der().to_vec());
+ tx.input[0].witness[1].push(SigHashType::All as u8);
+ tx.input[0].witness.push(Vec::new());
+ }
+
+ Self { tx }
+ }
+
+ pub fn txid(&self) -> Sha256dHash {
+ self.tx.txid()
+ }
+
+ pub fn has_local_sig(&self) -> bool {
+ if self.tx.input.len() != 1 { panic!("Commitment transactions must have input count == 1!"); }
+ if self.tx.input[0].witness.len() == 4 {
+ assert!(!self.tx.input[0].witness[1].is_empty());
+ assert!(!self.tx.input[0].witness[2].is_empty());
+ true
+ } else {
+ assert_eq!(self.tx.input[0].witness.len(), 3);
+ assert!(self.tx.input[0].witness[0].is_empty());
+ assert!(self.tx.input[0].witness[1].is_empty() || self.tx.input[0].witness[2].is_empty());
+ false
+ }
+ }
+
+ pub fn add_local_sig<T: secp256k1::Signing>(&mut self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) {
+ if self.has_local_sig() { return; }
+ let sighash = hash_to_message!(&bip143::SighashComponents::new(&self.tx)
+ .sighash_all(&self.tx.input[0], funding_redeemscript, channel_value_satoshis)[..]);
+ let our_sig = secp_ctx.sign(&sighash, funding_key);
+
+ if self.tx.input[0].witness[1].is_empty() {
+ self.tx.input[0].witness[1] = our_sig.serialize_der().to_vec();
+ self.tx.input[0].witness[1].push(SigHashType::All as u8);
+ } else {
+ self.tx.input[0].witness[2] = our_sig.serialize_der().to_vec();
+ self.tx.input[0].witness[2].push(SigHashType::All as u8);
+ }
+
+ self.tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
+ }
+
+ pub fn without_valid_witness(&self) -> &Transaction { &self.tx }
+ pub fn with_valid_witness(&self) -> &Transaction {
+ assert!(self.has_local_sig());
+ &self.tx
+ }
+}
+impl PartialEq for LocalCommitmentTransaction {
+ // We dont care whether we are signed in equality comparison
+ fn eq(&self, o: &Self) -> bool {
+ self.txid() == o.txid()
+ }
+}
+impl Writeable for LocalCommitmentTransaction {
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ if let Err(e) = self.tx.consensus_encode(&mut WriterWriteAdaptor(writer)) {
+ match e {
+ encode::Error::Io(e) => return Err(e),
+ _ => panic!("local tx must have been well-formed!"),
+ }
+ }
+ Ok(())
+ }
+}
+impl<R: ::std::io::Read> Readable<R> for LocalCommitmentTransaction {
+ fn read(reader: &mut R) -> Result<Self, DecodeError> {
+ let tx = match Transaction::consensus_decode(reader.by_ref()) {
+ Ok(tx) => tx,
+ Err(e) => match e {
+ encode::Error::Io(ioe) => return Err(DecodeError::Io(ioe)),
+ _ => return Err(DecodeError::InvalidValue),
+ },
+ };
+
+ if tx.input.len() != 1 {
+ // Ensure tx didn't hit the 0-input ambiguity case.
+ return Err(DecodeError::InvalidValue);
+ }
+ Ok(Self { tx })
+ }
+}
projects / rust-lightning / blobdiff