use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut};
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_hashes::hash160::Hash as Hash160;
use secp256k1::key::{SecretKey, PublicKey};
use secp256k1::{Secp256k1, Signature, Signing};
use secp256k1;
use util::byte_utils;
use util::logger::Logger;
use util::ser::{Writeable, Writer, Readable};
use ln::chan_utils;
use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction};
use ln::msgs;
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::io::Error;
use ln::msgs::DecodeError;
#[derive(Clone, PartialEq)]
pub enum SpendableOutputDescriptor {
StaticOutput {
outpoint: OutPoint,
output: TxOut,
},
DynamicOutputP2WSH {
outpoint: OutPoint,
key: SecretKey,
witness_script: Script,
to_self_delay: u16,
output: TxOut,
},
DynamicOutputP2WPKH {
outpoint: OutPoint,
key: SecretKey,
output: TxOut,
}
}
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::DynamicOutputP2WSH { ref outpoint, ref key, ref witness_script, ref to_self_delay, ref output } => {
1u8.write(writer)?;
outpoint.write(writer)?;
key.write(writer)?;
witness_script.write(writer)?;
to_self_delay.write(writer)?;
output.write(writer)?;
},
&SpendableOutputDescriptor::DynamicOutputP2WPKH { ref outpoint, ref key, ref output } => {
2u8.write(writer)?;
outpoint.write(writer)?;
key.write(writer)?;
output.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::DynamicOutputP2WSH {
outpoint: Readable::read(reader)?,
key: Readable::read(reader)?,
witness_script: Readable::read(reader)?,
to_self_delay: Readable::read(reader)?,
output: Readable::read(reader)?,
}),
2u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WPKH {
outpoint: Readable::read(reader)?,
key: Readable::read(reader)?,
output: Readable::read(reader)?,
}),
_ => Err(DecodeError::InvalidValue),
}
}
}
pub trait KeysInterface: Send + Sync {
type ChanKeySigner : ChannelKeys;
fn get_node_secret(&self) -> SecretKey;
fn get_destination_script(&self) -> Script;
fn get_shutdown_pubkey(&self) -> PublicKey;
fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner;
fn get_onion_rand(&self) -> (SecretKey, [u8; 32]);
fn get_channel_id(&self) -> [u8; 32];
}
pub trait ChannelKeys : Send+Clone {
fn funding_key<'a>(&'a self) -> &'a SecretKey;
fn revocation_base_key<'a>(&'a self) -> &'a SecretKey;
fn payment_base_key<'a>(&'a self) -> &'a SecretKey;
fn delayed_payment_base_key<'a>(&'a self) -> &'a SecretKey;
fn htlc_base_key<'a>(&'a self) -> &'a SecretKey;
fn commitment_seed<'a>(&'a self) -> &'a [u8; 32];
fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys;
fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
#[cfg(test)]
fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()>;
fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
fn set_remote_channel_pubkeys(&mut self, channel_points: &ChannelPublicKeys);
}
#[derive(Clone)]
pub struct InMemoryChannelKeys {
funding_key: SecretKey,
revocation_base_key: SecretKey,
payment_base_key: SecretKey,
delayed_payment_base_key: SecretKey,
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
pub(crate) local_channel_pubkeys: ChannelPublicKeys,
pub(crate) remote_channel_pubkeys: Option<ChannelPublicKeys>,
channel_value_satoshis: u64,
}
impl InMemoryChannelKeys {
pub fn new<C: Signing>(
secp_ctx: &Secp256k1<C>,
funding_key: SecretKey,
revocation_base_key: SecretKey,
payment_base_key: SecretKey,
delayed_payment_base_key: SecretKey,
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
channel_value_satoshis: u64) -> InMemoryChannelKeys {
let local_channel_pubkeys =
InMemoryChannelKeys::make_local_keys(secp_ctx, &funding_key, &revocation_base_key,
&payment_base_key, &delayed_payment_base_key,
&htlc_base_key);
InMemoryChannelKeys {
funding_key,
revocation_base_key,
payment_base_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
local_channel_pubkeys,
remote_channel_pubkeys: None,
}
}
fn make_local_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
funding_key: &SecretKey,
revocation_base_key: &SecretKey,
payment_base_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_basepoint: from_secret(&payment_base_key),
delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
htlc_basepoint: from_secret(&htlc_base_key),
}
}
}
impl ChannelKeys for InMemoryChannelKeys {
fn funding_key(&self) -> &SecretKey { &self.funding_key }
fn revocation_base_key(&self) -> &SecretKey { &self.revocation_base_key }
fn payment_base_key(&self) -> &SecretKey { &self.payment_base_key }
fn delayed_payment_base_key(&self) -> &SecretKey { &self.delayed_payment_base_key }
fn htlc_base_key(&self) -> &SecretKey { &self.htlc_base_key }
fn commitment_seed(&self) -> &[u8; 32] { &self.commitment_seed }
fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { &self.local_channel_pubkeys }
fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
if commitment_tx.input.len() != 1 { return Err(()); }
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
let commitment_sighash = hash_to_message!(&bip143::SighashComponents::new(&commitment_tx).sighash_all(&commitment_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]);
let commitment_sig = secp_ctx.sign(&commitment_sighash, &self.funding_key);
let commitment_txid = commitment_tx.txid();
let mut htlc_sigs = Vec::with_capacity(htlcs.len());
for ref htlc in htlcs {
if let Some(_) = htlc.transaction_output_index {
let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw, to_self_delay, htlc, &keys.a_delayed_payment_key, &keys.revocation_key);
let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
let our_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, &our_htlc_key));
}
}
Ok((commitment_sig, htlc_sigs))
}
fn sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
#[cfg(test)]
fn unsafe_sign_local_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
}
fn sign_local_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
local_commitment_tx.get_htlc_sigs(&self.htlc_base_key, local_csv, secp_ctx)
}
fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> 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 remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing");
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey);
let sighash = hash_to_message!(&bip143::SighashComponents::new(closing_tx)
.sighash_all(&closing_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]);
Ok(secp_ctx.sign(&sighash, &self.funding_key))
}
fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
Ok(secp_ctx.sign(&msghash, &self.funding_key))
}
fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) {
assert!(self.remote_channel_pubkeys.is_none(), "Already set remote channel pubkeys");
self.remote_channel_pubkeys = Some(channel_pubkeys.clone());
}
}
impl Writeable for InMemoryChannelKeys {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
self.funding_key.write(writer)?;
self.revocation_base_key.write(writer)?;
self.payment_base_key.write(writer)?;
self.delayed_payment_base_key.write(writer)?;
self.htlc_base_key.write(writer)?;
self.commitment_seed.write(writer)?;
self.remote_channel_pubkeys.write(writer)?;
self.channel_value_satoshis.write(writer)?;
Ok(())
}
}
impl Readable for InMemoryChannelKeys {
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_base_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 remote_channel_pubkeys = Readable::read(reader)?;
let channel_value_satoshis = Readable::read(reader)?;
let secp_ctx = Secp256k1::signing_only();
let local_channel_pubkeys =
InMemoryChannelKeys::make_local_keys(&secp_ctx, &funding_key, &revocation_base_key,
&payment_base_key, &delayed_payment_base_key,
&htlc_base_key);
Ok(InMemoryChannelKeys {
funding_key,
revocation_base_key,
payment_base_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
local_channel_pubkeys,
remote_channel_pubkeys
})
}
}
pub struct KeysManager {
secp_ctx: Secp256k1<secp256k1::SignOnly>,
node_secret: SecretKey,
destination_script: Script,
shutdown_pubkey: PublicKey,
channel_master_key: ExtendedPrivKey,
channel_child_index: AtomicUsize,
session_master_key: ExtendedPrivKey,
session_child_index: AtomicUsize,
channel_id_master_key: ExtendedPrivKey,
channel_id_child_index: AtomicUsize,
unique_start: Sha256State,
logger: Arc<Logger>,
}
impl KeysManager {
pub fn new(seed: &[u8; 32], network: Network, logger: Arc<Logger>, starting_time_secs: u64, starting_time_nanos: u32) -> KeysManager {
let secp_ctx = Secp256k1::signing_only();
match ExtendedPrivKey::new_master(network.clone(), 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 pubkey_hash160 = Hash160::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.key.serialize()[..]);
Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
.push_slice(&pubkey_hash160.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 session_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
let channel_id_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted");
let mut unique_start = Sha256::engine();
unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
unique_start.input(seed);
KeysManager {
secp_ctx,
node_secret,
destination_script,
shutdown_pubkey,
channel_master_key,
channel_child_index: AtomicUsize::new(0),
session_master_key,
session_child_index: AtomicUsize::new(0),
channel_id_master_key,
channel_id_child_index: AtomicUsize::new(0),
unique_start,
logger,
}
},
Err(_) => panic!("Your rng is busted"),
}
}
}
impl KeysInterface for KeysManager {
type ChanKeySigner = InMemoryChannelKeys;
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_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys {
let mut sha = self.unique_start.clone();
let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
let child_privkey = self.channel_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[..]);
let seed = Sha256::from_engine(sha).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_base_key = key_step!(b"payment base key", revocation_base_key);
let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_base_key);
let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
InMemoryChannelKeys::new(
&self.secp_ctx,
funding_key,
revocation_base_key,
payment_base_key,
delayed_payment_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis
)
}
fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) {
let mut sha = self.unique_start.clone();
let child_ix = self.session_child_index.fetch_add(1, Ordering::AcqRel);
let child_privkey = self.session_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[..]);
let mut rng_seed = sha.clone();
rng_seed.input(b"RNG Seed Salt");
sha.input(b"Session Key Salt");
(SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("Your RNG is busted"),
Sha256::from_engine(rng_seed).into_inner())
}
fn get_channel_id(&self) -> [u8; 32] {
let mut sha = self.unique_start.clone();
let child_ix = self.channel_id_child_index.fetch_add(1, Ordering::AcqRel);
let child_privkey = self.channel_id_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[..]);
Sha256::from_engine(sha).into_inner()
}
}