Merge pull request #1887 from TheBlueMatt/2022-11-definitely-valid

Remove cryptographically unreachable error conditions
This commit is contained in:
Matt Corallo 2022-12-03 19:01:15 +00:00 committed by GitHub
commit 14d2e97965
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
6 changed files with 122 additions and 142 deletions

View file

@ -2443,8 +2443,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
let secret = self.get_secret(commitment_number).unwrap();
let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key));
let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
let delayed_key = chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
@ -2556,31 +2556,18 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
} else { return (claimable_outpoints, to_counterparty_output_info); };
if let Some(transaction) = tx {
let revokeable_p2wsh_opt =
if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(
&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint)
{
if let Ok(delayed_key) = chan_utils::derive_public_key(&self.secp_ctx,
&per_commitment_point,
&self.counterparty_commitment_params.counterparty_delayed_payment_base_key)
{
Some(chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
self.counterparty_commitment_params.on_counterparty_tx_csv,
&delayed_key).to_v0_p2wsh())
} else {
debug_assert!(false, "Failed to derive a delayed payment key for a commitment state we accepted");
None
}
} else {
debug_assert!(false, "Failed to derive a revocation pubkey key for a commitment state we accepted");
None
};
if let Some(revokeable_p2wsh) = revokeable_p2wsh_opt {
for (idx, outp) in transaction.output.iter().enumerate() {
if outp.script_pubkey == revokeable_p2wsh {
to_counterparty_output_info =
Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
}
let revocation_pubkey = chan_utils::derive_public_revocation_key(
&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
let delayed_key = chan_utils::derive_public_key(&self.secp_ctx,
&per_commitment_point,
&self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
self.counterparty_commitment_params.on_counterparty_tx_csv,
&delayed_key).to_v0_p2wsh();
for (idx, outp) in transaction.output.iter().enumerate() {
if outp.script_pubkey == revokeable_p2wsh {
to_counterparty_output_info =
Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
}
}
}

View file

@ -655,8 +655,7 @@ impl InMemorySigner {
if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
.expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
@ -710,7 +709,7 @@ impl BaseSign for InMemorySigner {
let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
let htlc_sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
}
@ -743,11 +742,11 @@ impl BaseSign for InMemorySigner {
}
fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
let witness_script = {
let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_err(|_| ())?;
let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint);
chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
};
let mut sighash_parts = sighash::SighashCache::new(justice_tx);
@ -756,12 +755,12 @@ impl BaseSign for InMemorySigner {
}
fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
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(|_| ())?;
let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
};
let mut sighash_parts = sighash::SighashCache::new(justice_tx);
@ -770,19 +769,14 @@ impl BaseSign for InMemorySigner {
}
fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> 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(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, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
} else { return Err(()) }
} else { return Err(()) }
} else { return Err(()) };
let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
return Ok(sign(secp_ctx, &sighash, &htlc_key))
}
Err(())
let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
Ok(sign(secp_ctx, &sighash, &htlc_key))
}
fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {

View file

@ -381,57 +381,53 @@ impl PackageSolvingData {
fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
match self {
PackageSolvingData::RevokedOutput(ref outp) => {
if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
//TODO: should we panic on signer failure ?
if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(vec!(1));
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
} else { return false; }
}
let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
//TODO: should we panic on signer failure ?
if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(vec!(1));
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
} else { return false; }
},
PackageSolvingData::RevokedHTLCOutput(ref outp) => {
if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
//TODO: should we panic on signer failure ?
if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_htlc(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
} else { return false; }
}
let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
//TODO: should we panic on signer failure ?
if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_htlc(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
} else { return false; }
},
PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
}
if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
}
},
PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
bumped_tx.lock_time = PackedLockTime(outp.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) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
// Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
bumped_tx.input[i].witness.push(vec![]);
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
}
bumped_tx.lock_time = PackedLockTime(outp.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) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
let mut ser_sig = sig.serialize_der().to_vec();
ser_sig.push(EcdsaSighashType::All as u8);
bumped_tx.input[i].witness.push(ser_sig);
// Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
bumped_tx.input[i].witness.push(vec![]);
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
}
},
_ => { panic!("API Error!"); }

View file

@ -28,7 +28,6 @@ use crate::util::{byte_utils, transaction_utils};
use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
use bitcoin::secp256k1::Error as SecpError;
use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
use bitcoin::PublicKey as BitcoinPublicKey;
@ -330,32 +329,29 @@ impl Readable for CounterpartyCommitmentSecrets {
/// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
/// from the base secret and the per_commitment_point.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, SecpError> {
pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> SecretKey {
let mut sha = Sha256::engine();
sha.input(&per_commitment_point.serialize());
sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
let res = Sha256::from_engine(sha).into_inner();
base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap())
.expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
}
/// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
/// from the base point and the per_commitment_key. This is the public equivalent of
/// derive_private_key - using only public keys to derive a public key instead of private keys.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, SecpError> {
pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> PublicKey {
let mut sha = Sha256::engine();
sha.input(&per_commitment_point.serialize());
sha.input(&base_point.serialize());
let res = Sha256::from_engine(sha).into_inner();
let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&res)?);
let hashkey = PublicKey::from_secret_key(&secp_ctx,
&SecretKey::from_slice(&res).expect("Hashes should always be valid keys unless SHA-256 is broken"));
base_point.combine(&hashkey)
.expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
}
/// Derives a per-commitment-transaction revocation key from its constituent parts.
@ -364,10 +360,9 @@ pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_com
/// commitment transaction, thus per_commitment_secret always come from cheater
/// and revocation_base_secret always come from punisher, which is the broadcaster
/// of the transaction spending with this key knowledge.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey) -> Result<SecretKey, SecpError> {
pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>,
per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey)
-> SecretKey {
let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret);
let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
@ -386,9 +381,12 @@ pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1
Sha256::from_engine(sha).into_inner()
};
let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
.expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
.expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap())
.expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
}
/// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
@ -402,7 +400,9 @@ pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey) -> Result<PublicKey, SecpError> {
pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>,
per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey)
-> PublicKey {
let rev_append_commit_hash_key = {
let mut sha = Sha256::engine();
sha.input(&countersignatory_revocation_base_point.serialize());
@ -418,9 +418,12 @@ pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp2
Sha256::from_engine(sha).into_inner()
};
let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
.expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
.expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
countersignatory_contrib.combine(&broadcaster_contrib)
.expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
}
/// The set of public keys which are used in the creation of one commitment transaction.
@ -493,19 +496,19 @@ impl_writeable_tlv_based!(ChannelPublicKeys, {
impl TxCreationKeys {
/// Create per-state keys from channel base points and the per-commitment point.
/// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
pub fn derive_new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, broadcaster_delayed_payment_base: &PublicKey, broadcaster_htlc_base: &PublicKey, countersignatory_revocation_base: &PublicKey, countersignatory_htlc_base: &PublicKey) -> Result<TxCreationKeys, SecpError> {
Ok(TxCreationKeys {
pub fn derive_new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, broadcaster_delayed_payment_base: &PublicKey, broadcaster_htlc_base: &PublicKey, countersignatory_revocation_base: &PublicKey, countersignatory_htlc_base: &PublicKey) -> TxCreationKeys {
TxCreationKeys {
per_commitment_point: per_commitment_point.clone(),
revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base)?,
broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base)?,
countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base)?,
broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base)?,
})
revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base),
broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base),
countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base),
broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base),
}
}
/// Generate per-state keys from channel static keys.
/// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
pub fn from_channel_static_keys<T: secp256k1::Signing + secp256k1::Verification>(per_commitment_point: &PublicKey, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TxCreationKeys, SecpError> {
pub fn from_channel_static_keys<T: secp256k1::Signing + secp256k1::Verification>(per_commitment_point: &PublicKey, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> TxCreationKeys {
TxCreationKeys::derive_new(
&secp_ctx,
&per_commitment_point,
@ -1460,7 +1463,7 @@ impl CommitmentTransaction {
pub fn verify<T: secp256k1::Signing + secp256k1::Verification>(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TrustedCommitmentTransaction, ()> {
// This is the only field of the key cache that we trust
let per_commitment_point = self.keys.per_commitment_point;
let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx).unwrap();
let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx);
if keys != self.keys {
return Err(());
}
@ -1520,7 +1523,7 @@ impl<'a> TrustedCommitmentTransaction<'a> {
let keys = &inner.keys;
let txid = inner.built.txid;
let mut ret = Vec::with_capacity(inner.htlcs.len());
let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key).map_err(|_| ())?;
let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key);
for this_htlc in inner.htlcs.iter() {
assert!(this_htlc.transaction_output_index.is_some());
@ -1635,7 +1638,7 @@ mod tests {
let htlc_basepoint = &signer.pubkeys().htlc_basepoint;
let holder_pubkeys = signer.pubkeys();
let counterparty_pubkeys = counterparty_signer.pubkeys();
let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();
let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint);
let mut channel_parameters = ChannelTransactionParameters {
holder_pubkeys: holder_pubkeys.clone(),
holder_selected_contest_delay: 0,

View file

@ -1749,27 +1749,27 @@ impl<Signer: Sign> Channel<Signer> {
/// our counterparty!)
/// The result is a transaction which we can revoke broadcastership of (ie a "local" transaction)
/// TODO Some magic rust shit to compile-time check this?
fn build_holder_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError> {
fn build_holder_transaction_keys(&self, commitment_number: u64) -> TxCreationKeys {
let per_commitment_point = self.holder_signer.get_per_commitment_point(commitment_number, &self.secp_ctx);
let delayed_payment_base = &self.get_holder_pubkeys().delayed_payment_basepoint;
let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
let counterparty_pubkeys = self.get_counterparty_pubkeys();
Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint), "Local tx keys generation got bogus keys".to_owned()))
TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint)
}
#[inline]
/// Creates a set of keys for build_commitment_transaction to generate a transaction which we
/// will sign and send to our counterparty.
/// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
fn build_remote_transaction_keys(&self) -> Result<TxCreationKeys, ChannelError> {
fn build_remote_transaction_keys(&self) -> TxCreationKeys {
//TODO: Ensure that the payment_key derived here ends up in the library users' wallet as we
//may see payments to it!
let revocation_basepoint = &self.get_holder_pubkeys().revocation_basepoint;
let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
let counterparty_pubkeys = self.get_counterparty_pubkeys();
Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &self.counterparty_cur_commitment_point.unwrap(), &counterparty_pubkeys.delayed_payment_basepoint, &counterparty_pubkeys.htlc_basepoint, revocation_basepoint, htlc_basepoint), "Remote tx keys generation got bogus keys".to_owned()))
TxCreationKeys::derive_new(&self.secp_ctx, &self.counterparty_cur_commitment_point.unwrap(), &counterparty_pubkeys.delayed_payment_basepoint, &counterparty_pubkeys.htlc_basepoint, revocation_basepoint, htlc_basepoint)
}
/// Gets the redeemscript for the funding transaction output (ie the funding transaction output
@ -2157,7 +2157,7 @@ impl<Signer: Sign> Channel<Signer> {
fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
let funding_script = self.get_funding_redeemscript();
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number);
let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
{
let trusted_tx = initial_commitment_tx.trust();
@ -2171,7 +2171,7 @@ impl<Signer: Sign> Channel<Signer> {
secp_check!(self.secp_ctx.verify_ecdsa(&sighash, &sig, self.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
}
let counterparty_keys = self.build_remote_transaction_keys()?;
let counterparty_keys = self.build_remote_transaction_keys();
let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
@ -2285,7 +2285,7 @@ impl<Signer: Sign> Channel<Signer> {
let funding_script = self.get_funding_redeemscript();
let counterparty_keys = self.build_remote_transaction_keys()?;
let counterparty_keys = self.build_remote_transaction_keys();
let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
@ -2293,7 +2293,7 @@ impl<Signer: Sign> Channel<Signer> {
log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
let holder_signer = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
let holder_signer = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number);
let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx;
{
let trusted_tx = initial_commitment_tx.trust();
@ -2959,7 +2959,7 @@ impl<Signer: Sign> Channel<Signer> {
let funding_script = self.get_funding_redeemscript();
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number).map_err(|e| (None, e))?;
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number);
let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
let commitment_txid = {
@ -3551,7 +3551,7 @@ impl<Signer: Sign> Channel<Signer> {
// Before proposing a feerate update, check that we can actually afford the new fee.
let inbound_stats = self.get_inbound_pending_htlc_stats(Some(feerate_per_kw));
let outbound_stats = self.get_outbound_pending_htlc_stats(Some(feerate_per_kw));
let keys = if let Ok(keys) = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number) { keys } else { return None; };
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number);
let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.opt_anchors()) * 1000;
let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
@ -5221,7 +5221,7 @@ impl<Signer: Sign> Channel<Signer> {
/// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
fn get_outbound_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
let counterparty_keys = self.build_remote_transaction_keys()?;
let counterparty_keys = self.build_remote_transaction_keys();
let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
Ok(self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.secp_ctx)
.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
@ -5522,7 +5522,7 @@ impl<Signer: Sign> Channel<Signer> {
return Err(ChannelError::Ignore(format!("Cannot send value that would put us over the max HTLC value in flight our peer will accept ({})", self.counterparty_max_htlc_value_in_flight_msat)));
}
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number);
let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
if !self.is_outbound() {
// Check that we won't violate the remote channel reserve by adding this HTLC.
@ -5714,7 +5714,7 @@ impl<Signer: Sign> Channel<Signer> {
/// Only fails in case of bad keys. Used for channel_reestablish commitment_signed generation
/// when we shouldn't change HTLC/channel state.
fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
let counterparty_keys = self.build_remote_transaction_keys()?;
let counterparty_keys = self.build_remote_transaction_keys();
let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
let (signature, htlc_signatures);
@ -7309,7 +7309,7 @@ mod tests {
let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
let htlc_basepoint = &chan.holder_signer.pubkeys().htlc_basepoint;
let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();
let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint);
macro_rules! test_commitment {
( $counterparty_sig_hex: expr, $sig_hex: expr, $tx_hex: expr, $($remain:tt)* ) => {
@ -7962,16 +7962,16 @@ mod tests {
let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
assert_eq!(per_commitment_point.serialize()[..], hex::decode("025f7117a78150fe2ef97db7cfc83bd57b2e2c0d0dd25eaf467a4a1c2a45ce1486").unwrap()[..]);
assert_eq!(chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
assert_eq!(chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &base_point).serialize()[..],
hex::decode("0235f2dbfaa89b57ec7b055afe29849ef7ddfeb1cefdb9ebdc43f5494984db29e5").unwrap()[..]);
assert_eq!(chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &base_secret).unwrap(),
assert_eq!(chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &base_secret),
SecretKey::from_slice(&hex::decode("cbced912d3b21bf196a766651e436aff192362621ce317704ea2f75d87e7be0f").unwrap()[..]).unwrap());
assert_eq!(chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
assert_eq!(chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &base_point).serialize()[..],
hex::decode("02916e326636d19c33f13e8c0c3a03dd157f332f3e99c317c141dd865eb01f8ff0").unwrap()[..]);
assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret).unwrap(),
assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret),
SecretKey::from_slice(&hex::decode("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
}

View file

@ -705,7 +705,7 @@ fn test_update_fee_that_funder_cannot_afford() {
// Assemble the set of keys we can use for signatures for our commitment_signed message.
let commit_tx_keys = chan_utils::TxCreationKeys::derive_new(&secp_ctx, &remote_point, &remote_delayed_payment_basepoint,
&remote_htlc_basepoint, &local_revocation_basepoint, &local_htlc_basepoint).unwrap();
&remote_htlc_basepoint, &local_revocation_basepoint, &local_htlc_basepoint);
let res = {
let local_chan_lock = nodes[0].node.channel_state.lock().unwrap();
@ -1412,7 +1412,7 @@ fn test_fee_spike_violation_fails_htlc() {
// Assemble the set of keys we can use for signatures for our commitment_signed message.
let commit_tx_keys = chan_utils::TxCreationKeys::derive_new(&secp_ctx, &remote_point, &remote_delayed_payment_basepoint,
&remote_htlc_basepoint, &local_revocation_basepoint, &local_htlc_basepoint).unwrap();
&remote_htlc_basepoint, &local_revocation_basepoint, &local_htlc_basepoint);
// Build the remote commitment transaction so we can sign it, and then later use the
// signature for the commitment_signed message.