use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, SigHashType};
use bitcoin::blockdata::script::{Script, Builder};
use bitcoin::blockdata::opcodes;
use bitcoin::network::constants::Network;
use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
use bitcoin::util::bip143;
use bitcoin::hashes::{Hash, HashEngine};
use bitcoin::hashes::sha256::HashEngine as Sha256State;
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::sha256d::Hash as Sha256dHash;
use bitcoin::hash_types::WPubkeyHash;
use bitcoin::secp256k1::key::{SecretKey, PublicKey};
use bitcoin::secp256k1::{Secp256k1, Signature, Signing};
use bitcoin::secp256k1::recovery::RecoverableSignature;
use bitcoin::secp256k1;
use util::{byte_utils, transaction_utils};
use util::ser::{Writeable, Writer, Readable};
use chain::transaction::OutPoint;
use ln::chan_utils;
use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
use ln::msgs::UnsignedChannelAnnouncement;
use std::collections::HashSet;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::io::Error;
use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
#[derive(Clone, Debug, PartialEq)]
pub struct DelayedPaymentOutputDescriptor {
pub outpoint: OutPoint,
pub per_commitment_point: PublicKey,
pub to_self_delay: u16,
pub output: TxOut,
pub revocation_pubkey: PublicKey,
pub channel_keys_id: [u8; 32],
pub channel_value_satoshis: u64,
}
impl DelayedPaymentOutputDescriptor {
pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
}
#[derive(Clone, Debug, PartialEq)]
pub struct StaticPaymentOutputDescriptor {
pub outpoint: OutPoint,
pub output: TxOut,
pub channel_keys_id: [u8; 32],
pub channel_value_satoshis: u64,
}
impl StaticPaymentOutputDescriptor {
pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
}
#[derive(Clone, Debug, PartialEq)]
pub enum SpendableOutputDescriptor {
StaticOutput {
outpoint: OutPoint,
output: TxOut,
},
DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
StaticPaymentOutput(StaticPaymentOutputDescriptor),
}
impl Writeable for SpendableOutputDescriptor {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
match self {
&SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
0u8.write(writer)?;
outpoint.write(writer)?;
output.write(writer)?;
},
&SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) => {
1u8.write(writer)?;
descriptor.outpoint.write(writer)?;
descriptor.per_commitment_point.write(writer)?;
descriptor.to_self_delay.write(writer)?;
descriptor.output.write(writer)?;
descriptor.revocation_pubkey.write(writer)?;
descriptor.channel_keys_id.write(writer)?;
descriptor.channel_value_satoshis.write(writer)?;
},
&SpendableOutputDescriptor::StaticPaymentOutput(ref descriptor) => {
2u8.write(writer)?;
descriptor.outpoint.write(writer)?;
descriptor.output.write(writer)?;
descriptor.channel_keys_id.write(writer)?;
descriptor.channel_value_satoshis.write(writer)?;
},
}
Ok(())
}
}
impl Readable for SpendableOutputDescriptor {
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
match Readable::read(reader)? {
0u8 => Ok(SpendableOutputDescriptor::StaticOutput {
outpoint: Readable::read(reader)?,
output: Readable::read(reader)?,
}),
1u8 => Ok(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
outpoint: Readable::read(reader)?,
per_commitment_point: Readable::read(reader)?,
to_self_delay: Readable::read(reader)?,
output: Readable::read(reader)?,
revocation_pubkey: Readable::read(reader)?,
channel_keys_id: Readable::read(reader)?,
channel_value_satoshis: Readable::read(reader)?,
})),
2u8 => Ok(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
outpoint: Readable::read(reader)?,
output: Readable::read(reader)?,
channel_keys_id: Readable::read(reader)?,
channel_value_satoshis: Readable::read(reader)?,
})),
_ => Err(DecodeError::InvalidValue),
}
}
}
pub trait BaseSign {
fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
fn pubkeys(&self) -> &ChannelPublicKeys;
fn channel_keys_id(&self) -> [u8; 32];
fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
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, ()>;
fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
}
pub trait Sign: BaseSign + Writeable + Clone {
}
pub trait KeysInterface {
type Signer : Sign;
fn get_node_secret(&self) -> SecretKey;
fn get_destination_script(&self) -> Script;
fn get_shutdown_pubkey(&self) -> PublicKey;
fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
fn get_secure_random_bytes(&self) -> [u8; 32];
fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()>;
}
#[derive(Clone)]
pub struct InMemorySigner {
pub funding_key: SecretKey,
pub revocation_base_key: SecretKey,
pub payment_key: SecretKey,
pub delayed_payment_base_key: SecretKey,
pub htlc_base_key: SecretKey,
pub commitment_seed: [u8; 32],
pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
channel_parameters: Option<ChannelTransactionParameters>,
channel_value_satoshis: u64,
channel_keys_id: [u8; 32],
}
impl InMemorySigner {
pub fn new<C: Signing>(
secp_ctx: &Secp256k1<C>,
funding_key: SecretKey,
revocation_base_key: SecretKey,
payment_key: SecretKey,
delayed_payment_base_key: SecretKey,
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
channel_value_satoshis: u64,
channel_keys_id: [u8; 32]) -> InMemorySigner {
let holder_channel_pubkeys =
InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
&payment_key, &delayed_payment_base_key,
&htlc_base_key);
InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: None,
channel_keys_id,
}
}
fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
funding_key: &SecretKey,
revocation_base_key: &SecretKey,
payment_key: &SecretKey,
delayed_payment_base_key: &SecretKey,
htlc_base_key: &SecretKey) -> ChannelPublicKeys {
let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
ChannelPublicKeys {
funding_pubkey: from_secret(&funding_key),
revocation_basepoint: from_secret(&revocation_base_key),
payment_point: from_secret(&payment_key),
delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
htlc_basepoint: from_secret(&htlc_base_key),
}
}
pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
self.channel_parameters.as_ref().unwrap()
}
pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
if spend_tx.input.len() <= input_idx { return Err(()); }
if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
let remotepubkey = self.pubkeys().payment_point;
let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
let mut witness = Vec::with_capacity(2);
witness.push(remotesig.serialize_der().to_vec());
witness[0].push(SigHashType::All as u8);
witness.push(remotepubkey.serialize().to_vec());
Ok(witness)
}
pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
if spend_tx.input.len() <= input_idx { return Err(()); }
if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
if spend_tx.input[input_idx].sequence != 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_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!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
let mut witness = Vec::with_capacity(3);
witness.push(local_delayedsig.serialize_der().to_vec());
witness[0].push(SigHashType::All as u8);
witness.push(vec!());
witness.push(witness_script.clone().into_bytes());
Ok(witness)
}
}
impl BaseSign for InMemorySigner {
fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
PublicKey::from_secret_key(secp_ctx, &commitment_secret)
}
fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
chan_utils::build_commitment_secret(&self.commitment_seed, idx)
}
fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let trusted_tx = commitment_tx.trust();
let keys = trusted_tx.keys();
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let built_tx = trusted_tx.built_transaction();
let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
let commitment_txid = built_tx.txid;
let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
for htlc in commitment_tx.htlcs() {
let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
let holder_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) {
Ok(s) => s,
Err(_) => return Err(()),
};
htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key));
}
Ok((commitment_sig, htlc_sigs))
}
fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let trusted_tx = commitment_tx.trust();
let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
let channel_parameters = self.get_channel_parameters();
let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
Ok((sig, htlc_sigs))
}
#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let trusted_tx = commitment_tx.trust();
let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
let channel_parameters = self.get_channel_parameters();
let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
Ok((sig, htlc_sigs))
}
fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) {
Ok(revocation_key) => revocation_key,
Err(_) => return Err(())
};
let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
let revocation_pubkey = match chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
Ok(revocation_pubkey) => revocation_pubkey,
Err(_) => return Err(())
};
let witness_script = if let &Some(ref htlc) = htlc {
let counterparty_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
Ok(counterparty_htlcpubkey) => counterparty_htlcpubkey,
Err(_) => return Err(())
};
let holder_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
Ok(holder_htlcpubkey) => holder_htlcpubkey,
Err(_) => return Err(())
};
chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
} else {
let counterparty_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint) {
Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey,
Err(_) => return Err(())
};
chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
};
let mut sighash_parts = bip143::SigHashCache::new(justice_tx);
let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
return Ok(secp_ctx.sign(&sighash, &revocation_key))
}
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, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
} else { return Err(()) }
} else { return Err(()) }
} else { return Err(()) };
let mut sighash_parts = bip143::SigHashCache::new(htlc_tx);
let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]);
return Ok(secp_ctx.sign(&sighash, &htlc_key))
}
Err(())
}
fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
if closing_tx.input.len() != 1 { return Err(()); }
if closing_tx.input[0].witness.len() != 0 { return Err(()); }
if closing_tx.output.len() > 2 { return Err(()); }
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx)
.signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
Ok(secp_ctx.sign(&sighash, &self.funding_key))
}
fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
Ok(secp_ctx.sign(&msghash, &self.funding_key))
}
fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
assert!(self.channel_parameters.is_none(), "Acceptance already noted");
assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
self.channel_parameters = Some(channel_parameters.clone());
}
}
impl Sign for InMemorySigner {}
impl Writeable for InMemorySigner {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
self.funding_key.write(writer)?;
self.revocation_base_key.write(writer)?;
self.payment_key.write(writer)?;
self.delayed_payment_base_key.write(writer)?;
self.htlc_base_key.write(writer)?;
self.commitment_seed.write(writer)?;
self.channel_parameters.write(writer)?;
self.channel_value_satoshis.write(writer)?;
self.channel_keys_id.write(writer)?;
Ok(())
}
}
impl Readable for InMemorySigner {
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
let funding_key = Readable::read(reader)?;
let revocation_base_key = Readable::read(reader)?;
let payment_key = Readable::read(reader)?;
let delayed_payment_base_key = Readable::read(reader)?;
let htlc_base_key = Readable::read(reader)?;
let commitment_seed = Readable::read(reader)?;
let counterparty_channel_data = Readable::read(reader)?;
let channel_value_satoshis = Readable::read(reader)?;
let secp_ctx = Secp256k1::signing_only();
let holder_channel_pubkeys =
InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
&payment_key, &delayed_payment_base_key,
&htlc_base_key);
let keys_id = Readable::read(reader)?;
Ok(InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: counterparty_channel_data,
channel_keys_id: keys_id,
})
}
}
pub struct KeysManager {
secp_ctx: Secp256k1<secp256k1::All>,
node_secret: SecretKey,
destination_script: Script,
shutdown_pubkey: PublicKey,
channel_master_key: ExtendedPrivKey,
channel_child_index: AtomicUsize,
rand_bytes_master_key: ExtendedPrivKey,
rand_bytes_child_index: AtomicUsize,
rand_bytes_unique_start: Sha256State,
seed: [u8; 32],
starting_time_secs: u64,
starting_time_nanos: u32,
}
impl KeysManager {
pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
let secp_ctx = Secp256k1::new();
match ExtendedPrivKey::new_master(Network::Testnet, seed) {
Ok(master_key) => {
let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key;
let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
Ok(destination_key) => {
let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes());
Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
.push_slice(&wpubkey_hash.into_inner())
.into_script()
},
Err(_) => panic!("Your RNG is busted"),
};
let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
Ok(shutdown_key) => ExtendedPubKey::from_private(&secp_ctx, &shutdown_key).public_key.key,
Err(_) => panic!("Your RNG is busted"),
};
let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
let mut rand_bytes_unique_start = Sha256::engine();
rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
rand_bytes_unique_start.input(seed);
let mut res = KeysManager {
secp_ctx,
node_secret,
destination_script,
shutdown_pubkey,
channel_master_key,
channel_child_index: AtomicUsize::new(0),
rand_bytes_master_key,
rand_bytes_child_index: AtomicUsize::new(0),
rand_bytes_unique_start,
seed: *seed,
starting_time_secs,
starting_time_nanos,
};
let secp_seed = res.get_secure_random_bytes();
res.secp_ctx.seeded_randomize(&secp_seed);
res
},
Err(_) => panic!("Your rng is busted"),
}
}
pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
assert!(chan_id <= std::u32::MAX as u64);
let mut unique_start = Sha256::engine();
unique_start.input(params);
unique_start.input(&self.seed);
let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(chan_id as u32).expect("key space exhausted")).expect("Your RNG is busted");
unique_start.input(&child_privkey.private_key.key[..]);
let seed = Sha256::from_engine(unique_start).into_inner();
let commitment_seed = {
let mut sha = Sha256::engine();
sha.input(&seed);
sha.input(&b"commitment seed"[..]);
Sha256::from_engine(sha).into_inner()
};
macro_rules! key_step {
($info: expr, $prev_key: expr) => {{
let mut sha = Sha256::engine();
sha.input(&seed);
sha.input(&$prev_key[..]);
sha.input(&$info[..]);
SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
}}
}
let funding_key = key_step!(b"funding key", commitment_seed);
let revocation_base_key = key_step!(b"revocation base key", funding_key);
let payment_key = key_step!(b"payment key", revocation_base_key);
let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
InMemorySigner::new(
&self.secp_ctx,
funding_key,
revocation_base_key,
payment_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
params.clone()
)
}
pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
let mut input = Vec::new();
let mut input_value = 0;
let mut witness_weight = 0;
let mut output_set = HashSet::with_capacity(descriptors.len());
for outp in descriptors {
match outp {
SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
input.push(TxIn {
previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
script_sig: Script::new(),
sequence: 0,
witness: Vec::new(),
});
witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
input_value += descriptor.output.value;
if !output_set.insert(descriptor.outpoint) { return Err(()); }
},
SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
input.push(TxIn {
previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
script_sig: Script::new(),
sequence: descriptor.to_self_delay as u32,
witness: Vec::new(),
});
witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
input_value += descriptor.output.value;
if !output_set.insert(descriptor.outpoint) { return Err(()); }
},
SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
input.push(TxIn {
previous_output: outpoint.into_bitcoin_outpoint(),
script_sig: Script::new(),
sequence: 0,
witness: Vec::new(),
});
witness_weight += 1 + 73 + 34;
input_value += output.value;
if !output_set.insert(*outpoint) { return Err(()); }
}
}
if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
}
let mut spend_tx = Transaction {
version: 2,
lock_time: 0,
input,
output: outputs,
};
transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
let mut input_idx = 0;
for outp in descriptors {
match outp {
SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
keys_cache = Some((
self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
descriptor.channel_keys_id));
}
spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
},
SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
keys_cache = Some((
self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
descriptor.channel_keys_id));
}
spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
},
SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
let derivation_idx = if output.script_pubkey == self.destination_script {
1
} else {
2
};
let secret = {
match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
Ok(master_key) => {
match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
Ok(key) => key,
Err(_) => panic!("Your RNG is busted"),
}
}
Err(_) => panic!("Your rng is busted"),
}
};
let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
if derivation_idx == 2 {
assert_eq!(pubkey.key, self.shutdown_pubkey);
}
let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
},
}
input_idx += 1;
}
Ok(spend_tx)
}
}
impl KeysInterface for KeysManager {
type Signer = InMemorySigner;
fn get_node_secret(&self) -> SecretKey {
self.node_secret.clone()
}
fn get_destination_script(&self) -> Script {
self.destination_script.clone()
}
fn get_shutdown_pubkey(&self) -> PublicKey {
self.shutdown_pubkey.clone()
}
fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
assert!(child_ix <= std::u32::MAX as usize);
let mut id = [0; 32];
id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
self.derive_channel_keys(channel_value_satoshis, &id)
}
fn get_secure_random_bytes(&self) -> [u8; 32] {
let mut sha = self.rand_bytes_unique_start.clone();
let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
let child_privkey = self.rand_bytes_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
sha.input(&child_privkey.private_key.key[..]);
sha.input(b"Unique Secure Random Bytes Salt");
Sha256::from_engine(sha).into_inner()
}
fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
InMemorySigner::read(&mut std::io::Cursor::new(reader))
}
fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
}
}
#[test]
pub fn dyn_sign() {
let _signer: Box<dyn BaseSign>;
}