// licenses.
//! Various utilities for building scripts and deriving keys related to channels. These are
-//! largely of interest for those implementing chain::keysinterface::Sign message signing by hand.
+//! largely of interest for those implementing the traits on [`chain::keysinterface`] by hand.
use bitcoin::blockdata::script::{Script,Builder};
use bitcoin::blockdata::opcodes;
use crate::ln::{PaymentHash, PaymentPreimage};
use crate::ln::msgs::DecodeError;
use crate::util::ser::{Readable, Writeable, Writer};
-use crate::util::{byte_utils, transaction_utils};
+use crate::util::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;
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
for &(ref secret, ref idx) in self.old_secrets.iter() {
writer.write_all(secret)?;
- writer.write_all(&byte_utils::be64_to_array(*idx))?;
+ writer.write_all(&idx.to_be_bytes())?;
}
write_tlv_fields!(writer, {});
Ok(())
/// 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.
/// 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);
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
///
/// 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());
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.
});
/// One counterparty's public keys which do not change over the life of a channel.
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelPublicKeys {
/// The public key which is used to sign all commitment transactions, as it appears in the
/// on-chain channel lock-in 2-of-2 multisig output.
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,
let broadcaster_funding_key = broadcaster.serialize();
let countersignatory_funding_key = countersignatory.serialize();
+ make_funding_redeemscript_from_slices(&broadcaster_funding_key, &countersignatory_funding_key)
+}
+
+pub(crate) fn make_funding_redeemscript_from_slices(broadcaster_funding_key: &[u8], countersignatory_funding_key: &[u8]) -> Script {
let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
if broadcaster_funding_key[..] < countersignatory_funding_key[..] {
- builder.push_slice(&broadcaster_funding_key)
- .push_slice(&countersignatory_funding_key)
+ builder.push_slice(broadcaster_funding_key)
+ .push_slice(countersignatory_funding_key)
} else {
- builder.push_slice(&countersignatory_funding_key)
- .push_slice(&broadcaster_funding_key)
+ builder.push_slice(countersignatory_funding_key)
+ .push_slice(broadcaster_funding_key)
}.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
}
/// commitment transaction).
pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool, use_non_zero_fee_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
let mut txins: Vec<TxIn> = Vec::new();
- txins.push(TxIn {
+ txins.push(build_htlc_input(commitment_txid, htlc, opt_anchors));
+
+ let mut txouts: Vec<TxOut> = Vec::new();
+ txouts.push(build_htlc_output(
+ feerate_per_kw, contest_delay, htlc, opt_anchors, use_non_zero_fee_anchors,
+ broadcaster_delayed_payment_key, revocation_key
+ ));
+
+ Transaction {
+ version: 2,
+ lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }),
+ input: txins,
+ output: txouts,
+ }
+}
+
+pub(crate) fn build_htlc_input(commitment_txid: &Txid, htlc: &HTLCOutputInCommitment, opt_anchors: bool) -> TxIn {
+ TxIn {
previous_output: OutPoint {
txid: commitment_txid.clone(),
vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
script_sig: Script::new(),
sequence: Sequence(if opt_anchors { 1 } else { 0 }),
witness: Witness::new(),
- });
+ }
+}
+pub(crate) fn build_htlc_output(
+ feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool,
+ use_non_zero_fee_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey
+) -> TxOut {
let weight = if htlc.offered {
htlc_timeout_tx_weight(opt_anchors)
} else {
htlc.amount_msat / 1000 - total_fee
};
- let mut txouts: Vec<TxOut> = Vec::new();
- txouts.push(TxOut {
+ TxOut {
script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
value: output_value,
- });
+ }
+}
- Transaction {
- version: 2,
- lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }),
- input: txins,
- output: txouts,
+/// Returns the witness required to satisfy and spend a HTLC input.
+pub fn build_htlc_input_witness(
+ local_sig: &Signature, remote_sig: &Signature, preimage: &Option<PaymentPreimage>,
+ redeem_script: &Script, opt_anchors: bool,
+) -> Witness {
+ let remote_sighash_type = if opt_anchors {
+ EcdsaSighashType::SinglePlusAnyoneCanPay
+ } else {
+ EcdsaSighashType::All
+ };
+
+ let mut witness = Witness::new();
+ // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
+ witness.push(vec![]);
+ witness.push_bitcoin_signature(&remote_sig.serialize_der(), remote_sighash_type);
+ witness.push_bitcoin_signature(&local_sig.serialize_der(), EcdsaSighashType::All);
+ if let Some(preimage) = preimage {
+ witness.push(preimage.0.to_vec());
+ } else {
+ // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
+ witness.push(vec![]);
}
+ witness.push(redeem_script.to_bytes());
+ witness
}
/// Gets the witnessScript for the to_remote output when anchors are enabled.
/// Returns the witness required to satisfy and spend an anchor input.
pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness {
let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key);
- let mut funding_sig = funding_sig.serialize_der().to_vec();
- funding_sig.push(EcdsaSighashType::All as u8);
- Witness::from_vec(vec![funding_sig, anchor_redeem_script.to_bytes()])
+ let mut ret = Witness::new();
+ ret.push_bitcoin_signature(&funding_sig.serialize_der(), EcdsaSighashType::All);
+ ret.push(anchor_redeem_script.as_bytes());
+ ret
}
/// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
///
/// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters
/// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelTransactionParameters {
/// Holder public keys
pub holder_pubkeys: ChannelPublicKeys,
}
/// Late-bound per-channel counterparty data used to build transactions.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
pub struct CounterpartyChannelTransactionParameters {
/// Counter-party public keys
pub pubkeys: ChannelPublicKeys,
// First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
let mut tx = self.inner.built.transaction.clone();
tx.input[0].witness.push(Vec::new());
- let mut ser_holder_sig = holder_sig.serialize_der().to_vec();
- ser_holder_sig.push(EcdsaSighashType::All as u8);
- let mut ser_cp_sig = self.counterparty_sig.serialize_der().to_vec();
- ser_cp_sig.push(EcdsaSighashType::All as u8);
if self.holder_sig_first {
- tx.input[0].witness.push(ser_holder_sig);
- tx.input[0].witness.push(ser_cp_sig);
+ tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
+ tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
} else {
- tx.input[0].witness.push(ser_cp_sig);
- tx.input[0].witness.push(ser_holder_sig);
+ tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
+ tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
}
tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
///
/// Only include HTLCs that are above the dust limit for the channel.
///
- /// (C-not exported) due to the generic though we likely should expose a version without
+ /// This is not exported to bindings users due to the generic though we likely should expose a version without
pub fn new_with_auxiliary_htlc_data<T>(commitment_number: u64, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, opt_anchors: bool, broadcaster_funding_key: PublicKey, countersignatory_funding_key: PublicKey, keys: TxCreationKeys, feerate_per_kw: u32, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters) -> CommitmentTransaction {
// Sort outputs and populate output indices while keeping track of the auxiliary data
let (outputs, htlcs) = Self::internal_build_outputs(&keys, to_broadcaster_value_sat, to_countersignatory_value_sat, htlcs_with_aux, channel_parameters, opt_anchors, &broadcaster_funding_key, &countersignatory_funding_key).unwrap();
/// Use non-zero fee anchors
///
- /// (C-not exported) due to move, and also not likely to be useful for binding users
+ /// This is not exported to bindings users due to move, and also not likely to be useful for binding users
pub fn with_non_zero_fee_anchors(mut self) -> Self {
self.opt_non_zero_fee_anchors = Some(());
self
/// which were included in this commitment transaction in output order.
/// The transaction index is always populated.
///
- /// (C-not exported) as we cannot currently convert Vec references to/from C, though we should
+ /// This is not exported to bindings users as we cannot currently convert Vec references to/from C, though we should
/// expose a less effecient version which creates a Vec of references in the future.
pub fn htlcs(&self) -> &Vec<HTLCOutputInCommitment> {
&self.htlcs
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(());
}
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());
let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
- let sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
-
- // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
- htlc_tx.input[0].witness.push(Vec::new());
-
- let mut cp_sig_ser = counterparty_signature.serialize_der().to_vec();
- cp_sig_ser.push(sighashtype as u8);
- htlc_tx.input[0].witness.push(cp_sig_ser);
- let mut holder_sig_ser = signature.serialize_der().to_vec();
- holder_sig_ser.push(EcdsaSighashType::All as u8);
- htlc_tx.input[0].witness.push(holder_sig_ser);
-
- if this_htlc.offered {
- // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
- htlc_tx.input[0].witness.push(Vec::new());
- } else {
- htlc_tx.input[0].witness.push(preimage.unwrap().0.to_vec());
- }
-
- htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
+ htlc_tx.input[0].witness = chan_utils::build_htlc_input_witness(
+ signature, counterparty_signature, preimage, &htlc_redeemscript, self.opt_anchors(),
+ );
htlc_tx
}
}
use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
use crate::util::test_utils;
- use crate::chain::keysinterface::{KeysInterface, BaseSign};
+ use crate::chain::keysinterface::{ChannelSigner, SignerProvider};
use bitcoin::{Network, Txid};
use bitcoin::hashes::Hash;
use crate::ln::PaymentHash;
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,
projects / rust-lightning / blobdiff