mirrors/rust-lightning
1
0
Fork 0
mirror of https://github.com/lightningdevkit/rust-lightning.git synced 2025-02-24 23:08:36 +01:00
Code Issues Projects Releases Packages Wiki Activity

Dry-up witnessScript in sign_remote_htlc_transaction

Browse source 
Instead of blindly signing provided witnessScript, signer must derive
channel keys corresponding to the provided per-commitment-point and
regenerate templated witnessScript to ensure its syntax correctness.
This commit is contained in:
Antoine Riard 2020-05-04 02:35:54 -04:00
parent 479e1c8ddf
commit 06445b6189
3 changed files with 15 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
lightning/src/chain/keysinterface.rs
View file

@ -25,7 +25,6 @@ use util::ser::{Writeable, Writer, Readable};
use ln::chan_utils;
use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction};
use ln::msgs;
use ln::channelmanager::PaymentPreimage;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::io::Error;
@ -311,10 +310,10 @@ pub trait ChannelKeys : Send+Clone {
///
/// Amount is value of the output spent by this input, committed by sigs (BIP 143).
///
/// Preimage is solution for an offered HTLC haslock. A preimage sets to None hints this
/// htlc_tx as timing-out funds back to us on a received output.
//TODO: dry-up witness_script and pass pubkeys
fn sign_remote_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_point: &PublicKey, preimage: &Option<PaymentPreimage>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
/// Per_commitment_point is the dynamic point corresponding to the channel state
/// detected onchain. It has been generated by remote party and is used to derive
/// channel state keys, committed as part of witnessScript by sigs (BIP 143).
fn sign_remote_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
/// Create a signature for a (proposed) closing transaction.
///
@ -503,8 +502,15 @@ impl ChannelKeys for InMemoryChannelKeys {
return Ok(secp_ctx.sign(&sighash, &revocation_key))
}
fn sign_remote_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_point: &PublicKey, preimage: &Option<PaymentPreimage>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
fn sign_remote_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
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(remote_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.remote_pubkeys().htlc_basepoint) {
if let Ok(local_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &remote_htlcpubkey, &local_htlcpubkey, &revocation_pubkey)
} else { return Err(()) }
} else { return Err(()) }
} else { return Err(()) };
let sighash_parts = bip143::SighashComponents::new(&htlc_tx);
let sighash = hash_to_message!(&sighash_parts.sighash_all(&htlc_tx.input[input], &witness_script, amount)[..]);
return Ok(secp_ctx.sign(&sighash, &htlc_key))

2
lightning/src/ln/onchaintx.rs
View file

@ -602,7 +602,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key);
if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &witness_script, htlc.amount_msat / 1000, &per_commitment_point, preimage, &self.secp_ctx) {
if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx) {
bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
if let &Some(preimage) = preimage {

4
lightning/src/util/enforcing_trait_impls.rs
View file

@ -110,8 +110,8 @@ impl ChannelKeys for EnforcingChannelKeys {
Ok(self.inner.sign_justice_transaction(justice_tx, input, amount, per_commitment_key, htlc, on_remote_tx_csv, secp_ctx).unwrap())
}
fn sign_remote_htlc_transaction<T: secp256k1::Signing>(&self, htlc_tx: &Transaction, input: usize, witness_script: &Script, amount: u64, per_commitment_point: &PublicKey, preimage: &Option<PaymentPreimage>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
Ok(self.inner.sign_remote_htlc_transaction(htlc_tx, input, witness_script, amount, per_commitment_point, preimage, secp_ctx).unwrap())
fn sign_remote_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
Ok(self.inner.sign_remote_htlc_transaction(htlc_tx, input, amount, per_commitment_point, htlc, secp_ctx).unwrap())
}
fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {