+//! The logic to monitor for on-chain transactions and create the relevant claim responses lives
+//! here.
+//!
+//! ChannelMonitor objects are generated by ChannelManager in response to relevant
+//! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
+//! be made in responding to certain messages, see ManyChannelMonitor for more.
+//!
+//! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
+//! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
+//! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
+//! security-domain-separated system design, you should consider having multiple paths for
+//! ChannelMonitors to get out of the HSM and onto monitoring devices.
+
use bitcoin::blockdata::block::BlockHeader;
use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction};
use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
use secp256k1::key::{SecretKey,PublicKey};
use secp256k1;
-use ln::msgs::HandleError;
+use ln::msgs::{DecodeError, HandleError};
use ln::chan_utils;
use ln::chan_utils::HTLCOutputInCommitment;
use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
use chain::transaction::OutPoint;
+use util::ser::{Readable, Writer};
use util::sha2::Sha256;
use util::byte_utils;
use std::sync::{Arc,Mutex};
use std::{hash,cmp};
+/// An error enum representing a failure to persist a channel monitor update.
pub enum ChannelMonitorUpdateErr {
/// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
/// to succeed at some point in the future).
+ ///
/// Such a failure will "freeze" a channel, preventing us from revoking old states or
/// submitting new commitment transactions to the remote party.
/// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
/// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
/// events to it, while also taking any add_update_monitor events and passing them to some remote
/// server(s).
+///
/// Note that any updates to a channel's monitor *must* be applied to each instance of the
/// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
/// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
/// which we have revoked, allowing our counterparty to claim all funds in the channel!
pub trait ManyChannelMonitor: Send + Sync {
/// Adds or updates a monitor for the given `funding_txo`.
+ ///
/// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
/// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
/// any spends of it.
/// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
/// watchtower or watch our own channels.
+///
/// Note that you must provide your own key by which to refer to channels.
+///
/// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
/// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
/// index by a PublicKey which is required to sign any updates.
+///
/// If you're using this for local monitoring of your own channels, you probably want to use
/// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
pub struct SimpleManyChannelMonitor<Key> {
+ #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
+ pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
+ #[cfg(not(test))]
monitors: Mutex<HashMap<Key, ChannelMonitor>>,
chain_monitor: Arc<ChainWatchInterface>,
broadcaster: Arc<BroadcasterInterface>
}
impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
+ /// Creates a new object which can be used to monitor several channels given the chain
+ /// interface with which to register to receive notifications.
pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
let res = Arc::new(SimpleManyChannelMonitor {
monitors: Mutex::new(HashMap::new()),
res
}
+ /// Adds or udpates the monitor which monitors the channel referred to by the given key.
pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
let mut monitors = self.monitors.lock().unwrap();
match monitors.get_mut(&key) {
const SERIALIZATION_VERSION: u8 = 1;
const MIN_SERIALIZATION_VERSION: u8 = 1;
+/// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
+/// on-chain transactions to ensure no loss of funds occurs.
+///
+/// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
+/// information and are actively monitoring the chain.
pub struct ChannelMonitor {
funding_txo: Option<(OutPoint, Script)>,
commitment_transaction_number_obscure_factor: u64,
key_storage: KeyStorage,
delayed_payment_base_key: PublicKey,
their_htlc_base_key: Option<PublicKey>,
+ their_delayed_payment_base_key: Option<PublicKey>,
// first is the idx of the first of the two revocation points
their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
key_storage: self.key_storage.clone(),
delayed_payment_base_key: self.delayed_payment_base_key.clone(),
their_htlc_base_key: self.their_htlc_base_key.clone(),
+ their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
their_cur_revocation_points: self.their_cur_revocation_points.clone(),
our_to_self_delay: self.our_to_self_delay,
self.key_storage != other.key_storage ||
self.delayed_payment_base_key != other.delayed_payment_base_key ||
self.their_htlc_base_key != other.their_htlc_base_key ||
+ self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
self.their_cur_revocation_points != other.their_cur_revocation_points ||
self.our_to_self_delay != other.our_to_self_delay ||
self.their_to_self_delay != other.their_to_self_delay ||
}
impl ChannelMonitor {
- pub fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
+ pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
ChannelMonitor {
funding_txo: None,
commitment_transaction_number_obscure_factor: 0,
},
delayed_payment_base_key: delayed_payment_base_key.clone(),
their_htlc_base_key: None,
+ their_delayed_payment_base_key: None,
their_cur_revocation_points: None,
our_to_self_delay: our_to_self_delay,
self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
}
+ /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
+ /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
+ /// chain for new blocks/transactions.
pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
if self.funding_txo.is_some() {
// We should be able to compare the entire funding_txo, but in fuzztarget its trivially
self.funding_txo = Some(funding_info);
}
- pub(super) fn set_their_htlc_base_key(&mut self, their_htlc_base_key: &PublicKey) {
+ /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
+ pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
self.their_htlc_base_key = Some(their_htlc_base_key.clone());
+ self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
}
pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
self.funding_txo = None;
}
+ /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
pub fn get_funding_txo(&self) -> Option<OutPoint> {
match self.funding_txo {
Some((outpoint, _)) => Some(outpoint),
}
/// Serializes into a vec, with various modes for the exposed pub fns
- fn serialize(&self, for_local_storage: bool) -> Vec<u8> {
- let mut res = Vec::new();
- res.push(SERIALIZATION_VERSION);
- res.push(MIN_SERIALIZATION_VERSION);
+ fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
+ //TODO: We still write out all the serialization here manually instead of using the fancy
+ //serialization framework we have, we should migrate things over to it.
+ writer.write_all(&[SERIALIZATION_VERSION; 1])?;
+ writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
match &self.funding_txo {
&Some((ref outpoint, ref script)) => {
- res.extend_from_slice(&outpoint.txid[..]);
- res.extend_from_slice(&byte_utils::be16_to_array(outpoint.index));
- res.extend_from_slice(&byte_utils::be64_to_array(script.len() as u64));
- res.extend_from_slice(&script[..]);
+ writer.write_all(&outpoint.txid[..])?;
+ writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
+ writer.write_all(&byte_utils::be64_to_array(script.len() as u64))?;
+ writer.write_all(&script[..])?;
},
&None => {
// We haven't even been initialized...not sure why anyone is serializing us, but
// not much to give them.
- return res;
+ return Ok(());
},
}
// Set in initial Channel-object creation, so should always be set by now:
- res.extend_from_slice(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor));
+ writer.write_all(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor))?;
match self.key_storage {
KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
- res.push(0);
- res.extend_from_slice(&revocation_base_key[..]);
- res.extend_from_slice(&htlc_base_key[..]);
+ writer.write_all(&[0; 1])?;
+ writer.write_all(&revocation_base_key[..])?;
+ writer.write_all(&htlc_base_key[..])?;
},
KeyStorage::SigsMode { .. } => unimplemented!(),
}
- res.extend_from_slice(&self.delayed_payment_base_key.serialize());
- res.extend_from_slice(&self.their_htlc_base_key.as_ref().unwrap().serialize());
+ writer.write_all(&self.delayed_payment_base_key.serialize())?;
+ writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
+ writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
match self.their_cur_revocation_points {
Some((idx, pubkey, second_option)) => {
- res.extend_from_slice(&byte_utils::be48_to_array(idx));
- res.extend_from_slice(&pubkey.serialize());
+ writer.write_all(&byte_utils::be48_to_array(idx))?;
+ writer.write_all(&pubkey.serialize())?;
match second_option {
Some(second_pubkey) => {
- res.extend_from_slice(&second_pubkey.serialize());
+ writer.write_all(&second_pubkey.serialize())?;
},
None => {
- res.extend_from_slice(&[0; 33]);
+ writer.write_all(&[0; 33])?;
},
}
},
None => {
- res.extend_from_slice(&byte_utils::be48_to_array(0));
+ writer.write_all(&byte_utils::be48_to_array(0))?;
},
}
- res.extend_from_slice(&byte_utils::be16_to_array(self.our_to_self_delay));
- res.extend_from_slice(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()));
+ writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
+ writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
for &(ref secret, ref idx) in self.old_secrets.iter() {
- res.extend_from_slice(secret);
- res.extend_from_slice(&byte_utils::be64_to_array(*idx));
+ writer.write_all(secret)?;
+ writer.write_all(&byte_utils::be64_to_array(*idx))?;
}
macro_rules! serialize_htlc_in_commitment {
($htlc_output: expr) => {
- res.push($htlc_output.offered as u8);
- res.extend_from_slice(&byte_utils::be64_to_array($htlc_output.amount_msat));
- res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.cltv_expiry));
- res.extend_from_slice(&$htlc_output.payment_hash);
- res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.transaction_output_index));
+ writer.write_all(&[$htlc_output.offered as u8; 1])?;
+ writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
+ writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
+ writer.write_all(&$htlc_output.payment_hash)?;
+ writer.write_all(&byte_utils::be32_to_array($htlc_output.transaction_output_index))?;
}
}
- res.extend_from_slice(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64));
+ writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
- res.extend_from_slice(&txid[..]);
- res.extend_from_slice(&byte_utils::be64_to_array(htlc_outputs.len() as u64));
+ writer.write_all(&txid[..])?;
+ writer.write_all(&byte_utils::be64_to_array(htlc_outputs.len() as u64))?;
for htlc_output in htlc_outputs.iter() {
serialize_htlc_in_commitment!(htlc_output);
}
{
let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
- res.extend_from_slice(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64));
+ writer.write_all(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64))?;
for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
- res.extend_from_slice(&txid[..]);
- res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
+ writer.write_all(&txid[..])?;
+ writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
}
}
if for_local_storage {
- res.extend_from_slice(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64));
+ writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
- res.extend_from_slice(payment_hash);
- res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
+ writer.write_all(payment_hash)?;
+ writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
}
} else {
- res.extend_from_slice(&byte_utils::be64_to_array(0));
+ writer.write_all(&byte_utils::be64_to_array(0))?;
}
macro_rules! serialize_local_tx {
($local_tx: expr) => {
let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
- res.extend_from_slice(&byte_utils::be64_to_array(tx_ser.len() as u64));
- res.extend_from_slice(&tx_ser);
+ writer.write_all(&byte_utils::be64_to_array(tx_ser.len() as u64))?;
+ writer.write_all(&tx_ser)?;
- res.extend_from_slice(&$local_tx.revocation_key.serialize());
- res.extend_from_slice(&$local_tx.a_htlc_key.serialize());
- res.extend_from_slice(&$local_tx.b_htlc_key.serialize());
- res.extend_from_slice(&$local_tx.delayed_payment_key.serialize());
+ writer.write_all(&$local_tx.revocation_key.serialize())?;
+ writer.write_all(&$local_tx.a_htlc_key.serialize())?;
+ writer.write_all(&$local_tx.b_htlc_key.serialize())?;
+ writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
- res.extend_from_slice(&byte_utils::be64_to_array($local_tx.feerate_per_kw));
- res.extend_from_slice(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64));
+ writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
+ writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
serialize_htlc_in_commitment!(htlc_output);
- res.extend_from_slice(&their_sig.serialize_compact(&self.secp_ctx));
- res.extend_from_slice(&our_sig.serialize_compact(&self.secp_ctx));
+ writer.write_all(&their_sig.serialize_compact(&self.secp_ctx))?;
+ writer.write_all(&our_sig.serialize_compact(&self.secp_ctx))?;
}
}
}
if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
- res.push(1);
+ writer.write_all(&[1; 1])?;
serialize_local_tx!(prev_local_tx);
} else {
- res.push(0);
+ writer.write_all(&[0; 1])?;
}
if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
- res.push(1);
+ writer.write_all(&[1; 1])?;
serialize_local_tx!(cur_local_tx);
} else {
- res.push(0);
+ writer.write_all(&[0; 1])?;
}
- res.extend_from_slice(&byte_utils::be64_to_array(self.payment_preimages.len() as u64));
+ writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
for payment_preimage in self.payment_preimages.values() {
- res.extend_from_slice(payment_preimage);
+ writer.write_all(payment_preimage)?;
}
- res.extend_from_slice(&byte_utils::be64_to_array(self.destination_script.len() as u64));
- res.extend_from_slice(&self.destination_script[..]);
+ writer.write_all(&byte_utils::be64_to_array(self.destination_script.len() as u64))?;
+ writer.write_all(&self.destination_script[..])?;
- res
+ Ok(())
}
- /// Encodes this monitor into a byte array, suitable for writing to disk.
- pub fn serialize_for_disk(&self) -> Vec<u8> {
- self.serialize(true)
+ /// Writes this monitor into the given writer, suitable for writing to disk.
+ pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ self.write(writer, true)
}
- /// Encodes this monitor into a byte array, suitable for sending to a remote watchtower
- pub fn serialize_for_watchtower(&self) -> Vec<u8> {
- self.serialize(false)
- }
-
- /// Attempts to decode a serialized monitor
- pub fn deserialize(data: &[u8]) -> Option<Self> {
- let mut read_pos = 0;
- macro_rules! read_bytes {
- ($byte_count: expr) => {
- {
- if ($byte_count as usize) > data.len() - read_pos {
- return None;
- }
- read_pos += $byte_count as usize;
- &data[read_pos - $byte_count as usize..read_pos]
- }
- }
- }
-
- let secp_ctx = Secp256k1::new();
- macro_rules! unwrap_obj {
- ($key: expr) => {
- match $key {
- Ok(res) => res,
- Err(_) => return None,
- }
- }
- }
-
- let _ver = read_bytes!(1)[0];
- let min_ver = read_bytes!(1)[0];
- if min_ver > SERIALIZATION_VERSION {
- return None;
- }
-
- // Technically this can fail and serialize fail a round-trip, but only for serialization of
- // barely-init'd ChannelMonitors that we can't do anything with.
- let outpoint = OutPoint {
- txid: Sha256dHash::from(read_bytes!(32)),
- index: byte_utils::slice_to_be16(read_bytes!(2)),
- };
- let script_len = byte_utils::slice_to_be64(read_bytes!(8));
- let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
- let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
-
- let key_storage = match read_bytes!(1)[0] {
- 0 => {
- KeyStorage::PrivMode {
- revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
- htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
- }
- },
- _ => return None,
- };
-
- let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
-
- let their_cur_revocation_points = {
- let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
- if first_idx == 0 {
- None
- } else {
- let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let second_point_slice = read_bytes!(33);
- if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
- Some((first_idx, first_point, None))
- } else {
- Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
- }
- }
- };
-
- let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
- let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
-
- let mut old_secrets = [([0; 32], 1 << 48); 49];
- for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
- secret.copy_from_slice(read_bytes!(32));
- *idx = byte_utils::slice_to_be64(read_bytes!(8));
- }
-
- macro_rules! read_htlc_in_commitment {
- () => {
- {
- let offered = match read_bytes!(1)[0] {
- 0 => false, 1 => true,
- _ => return None,
- };
- let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
- let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
- let mut payment_hash = [0; 32];
- payment_hash[..].copy_from_slice(read_bytes!(32));
- let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
-
- HTLCOutputInCommitment {
- offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
- }
- }
- }
- }
-
- let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
- if remote_claimable_outpoints_len > data.len() as u64 / 64 { return None; }
- let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
- for _ in 0..remote_claimable_outpoints_len {
- let txid = Sha256dHash::from(read_bytes!(32));
- let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
- if outputs_count > data.len() as u64 / 32 { return None; }
- let mut outputs = Vec::with_capacity(outputs_count as usize);
- for _ in 0..outputs_count {
- outputs.push(read_htlc_in_commitment!());
- }
- if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
- return None;
- }
- }
-
- let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
- if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return None; }
- let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
- for _ in 0..remote_commitment_txn_on_chain_len {
- let txid = Sha256dHash::from(read_bytes!(32));
- let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
- if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
- return None;
- }
- }
-
- let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
- if remote_hash_commitment_number_len > data.len() as u64 / 32 { return None; }
- let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
- for _ in 0..remote_hash_commitment_number_len {
- let mut txid = [0; 32];
- txid[..].copy_from_slice(read_bytes!(32));
- let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
- if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
- return None;
- }
- }
-
- macro_rules! read_local_tx {
- () => {
- {
- let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
- let tx_ser = read_bytes!(tx_len);
- let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
- if serialize::serialize(&tx).unwrap() != tx_ser {
- // We check that the tx re-serializes to the same form to ensure there is
- // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
- // all that well.
- return None;
- }
-
- let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
- let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
-
- let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
- if htlc_outputs_len > data.len() as u64 / 128 { return None; }
- let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
- for _ in 0..htlc_outputs_len {
- htlc_outputs.push((read_htlc_in_commitment!(),
- unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
- unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
- }
-
- LocalSignedTx {
- txid: tx.txid(),
- tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
- }
- }
- }
- }
-
- let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
- 0 => None,
- 1 => {
- Some(read_local_tx!())
- },
- _ => return None,
- };
-
- let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
- 0 => None,
- 1 => {
- Some(read_local_tx!())
- },
- _ => return None,
- };
-
- let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
- if payment_preimages_len > data.len() as u64 / 32 { return None; }
- let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
- let mut sha = Sha256::new();
- for _ in 0..payment_preimages_len {
- let mut preimage = [0; 32];
- preimage[..].copy_from_slice(read_bytes!(32));
- sha.reset();
- sha.input(&preimage);
- let mut hash = [0; 32];
- sha.result(&mut hash);
- if let Some(_) = payment_preimages.insert(hash, preimage) {
- return None;
- }
- }
-
- let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
- let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
-
- Some(ChannelMonitor {
- funding_txo,
- commitment_transaction_number_obscure_factor,
-
- key_storage,
- delayed_payment_base_key,
- their_htlc_base_key,
- their_cur_revocation_points,
-
- our_to_self_delay,
- their_to_self_delay,
-
- old_secrets,
- remote_claimable_outpoints,
- remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
- remote_hash_commitment_number,
-
- prev_local_signed_commitment_tx,
- current_local_signed_commitment_tx,
-
- payment_preimages,
-
- destination_script,
- secp_ctx,
- })
+ /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
+ pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ self.write(writer, false)
}
//TODO: Functions to serialize/deserialize (with different forms depending on which information
//we want to leave out (eg funding_txo, etc).
/// Can only fail if idx is < get_min_seen_secret
- pub fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
+ pub(super) fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
for i in 0..self.old_secrets.len() {
if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
Err(HandleError{err: "idx too low", action: None})
}
- pub fn get_min_seen_secret(&self) -> u64 {
+ pub(super) fn get_min_seen_secret(&self) -> u64 {
//TODO This can be optimized?
let mut min = 1 << 48;
for &(_, idx) in self.old_secrets.iter() {
/// Attempts to claim a remote commitment transaction's outputs using the revocation key and
/// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
/// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
- /// HTLC-Success/HTLC-Timeout transactions, and claim them using the revocation key (if
- /// applicable) as well.
+ /// HTLC-Success/HTLC-Timeout transactions.
fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
// Most secp and related errors trying to create keys means we have no hope of constructing
// a spend transaction...so we return no transactions to broadcast
ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
},
};
- let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.delayed_payment_base_key));
+ let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
let a_htlc_key = match self.their_htlc_base_key {
None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
};
let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
- txn_to_broadcast.push(single_htlc_tx); // TODO: This is not yet tested in ChannelManager!
+ txn_to_broadcast.push(single_htlc_tx);
}
}
}
txn_to_broadcast.push(spend_tx);
}
}
- } else {
- //TODO: For each input check if its in our remote_commitment_txn_on_chain map!
}
(txn_to_broadcast, (commitment_txid, watch_outputs))
}
+ /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
+ fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
+ if tx.input.len() != 1 || tx.output.len() != 1 {
+ return None;
+ }
+
+ macro_rules! ignore_error {
+ ( $thing : expr ) => {
+ match $thing {
+ Ok(a) => a,
+ Err(_) => return None
+ }
+ };
+ }
+
+ let secret = ignore_error!(self.get_secret(commitment_number));
+ let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
+ let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
+ let revocation_pubkey = match self.key_storage {
+ KeyStorage::PrivMode { ref revocation_base_key, .. } => {
+ ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
+ },
+ KeyStorage::SigsMode { ref revocation_base_key, .. } => {
+ ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
+ },
+ };
+ let delayed_key = match self.their_delayed_payment_base_key {
+ None => return None,
+ Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
+ };
+ let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
+ let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
+ let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
+
+ let mut inputs = Vec::new();
+ let mut amount = 0;
+
+ if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
+ inputs.push(TxIn {
+ previous_output: BitcoinOutPoint {
+ txid: htlc_txid,
+ vout: 0,
+ },
+ script_sig: Script::new(),
+ sequence: 0xfffffffd,
+ witness: Vec::new(),
+ });
+ amount = tx.output[0].value;
+ }
+
+ if !inputs.is_empty() {
+ let outputs = vec!(TxOut {
+ script_pubkey: self.destination_script.clone(),
+ value: amount, //TODO: - fee
+ });
+
+ let mut spend_tx = Transaction {
+ version: 2,
+ lock_time: 0,
+ input: inputs,
+ output: outputs,
+ };
+
+ let sighash_parts = bip143::SighashComponents::new(&spend_tx);
+
+ let sig = match self.key_storage {
+ KeyStorage::PrivMode { ref revocation_base_key, .. } => {
+ let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]));
+ let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
+ self.secp_ctx.sign(&sighash, &revocation_key)
+ }
+ KeyStorage::SigsMode { .. } => {
+ unimplemented!();
+ }
+ };
+ spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
+ spend_tx.input[0].witness[0].push(SigHashType::All as u8);
+ spend_tx.input[0].witness.push(vec!(1));
+ spend_tx.input[0].witness.push(redeemscript.into_bytes());
+
+ Some(spend_tx)
+ } else { None }
+ }
+
fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
let mut watch_outputs = Vec::new();
for tx in txn_matched {
- for txin in tx.input.iter() {
- if self.funding_txo.is_none() || (txin.previous_output.txid == self.funding_txo.as_ref().unwrap().0.txid && txin.previous_output.vout == self.funding_txo.as_ref().unwrap().0.index as u32) {
- let (mut txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
+ if tx.input.len() == 1 {
+ // Assuming our keys were not leaked (in which case we're screwed no matter what),
+ // commitment transactions and HTLC transactions will all only ever have one input,
+ // which is an easy way to filter out any potential non-matching txn for lazy
+ // filters.
+ let prevout = &tx.input[0].previous_output;
+ let mut txn: Vec<Transaction> = Vec::new();
+ if self.funding_txo.is_none() || (prevout.txid == self.funding_txo.as_ref().unwrap().0.txid && prevout.vout == self.funding_txo.as_ref().unwrap().0.index as u32) {
+ let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
+ txn = remote_txn;
if !new_outputs.1.is_empty() {
watch_outputs.push(new_outputs);
}
if txn.is_empty() {
txn = self.check_spend_local_transaction(tx, height);
}
- for tx in txn.iter() {
- broadcaster.broadcast_transaction(tx);
+ } else {
+ let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
+ if let Some(commitment_number) = remote_commitment_txn_on_chain.get(&prevout.txid) {
+ if let Some(tx) = self.check_spend_remote_htlc(tx, *commitment_number) {
+ txn.push(tx);
+ }
}
}
+ for tx in txn.iter() {
+ broadcaster.broadcast_transaction(tx);
+ }
}
}
if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
watch_outputs
}
- pub fn would_broadcast_at_height(&self, height: u32) -> bool {
+ pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
}
}
+impl<R: ::std::io::Read> Readable<R> for ChannelMonitor {
+ fn read(reader: &mut R) -> Result<Self, DecodeError> {
+ // TODO: read_to_end and then deserializing from that vector is really dumb, we should
+ // actually use the fancy serialization framework we have instead of hacking around it.
+ let mut datavec = Vec::new();
+ reader.read_to_end(&mut datavec)?;
+ let data = &datavec;
+
+ let mut read_pos = 0;
+ macro_rules! read_bytes {
+ ($byte_count: expr) => {
+ {
+ if ($byte_count as usize) > data.len() - read_pos {
+ return Err(DecodeError::ShortRead);
+ }
+ read_pos += $byte_count as usize;
+ &data[read_pos - $byte_count as usize..read_pos]
+ }
+ }
+ }
+
+ let secp_ctx = Secp256k1::new();
+ macro_rules! unwrap_obj {
+ ($key: expr) => {
+ match $key {
+ Ok(res) => res,
+ Err(_) => return Err(DecodeError::InvalidValue),
+ }
+ }
+ }
+
+ let _ver = read_bytes!(1)[0];
+ let min_ver = read_bytes!(1)[0];
+ if min_ver > SERIALIZATION_VERSION {
+ return Err(DecodeError::UnknownVersion);
+ }
+
+ // Technically this can fail and serialize fail a round-trip, but only for serialization of
+ // barely-init'd ChannelMonitors that we can't do anything with.
+ let outpoint = OutPoint {
+ txid: Sha256dHash::from(read_bytes!(32)),
+ index: byte_utils::slice_to_be16(read_bytes!(2)),
+ };
+ let script_len = byte_utils::slice_to_be64(read_bytes!(8));
+ let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
+ let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
+
+ let key_storage = match read_bytes!(1)[0] {
+ 0 => {
+ KeyStorage::PrivMode {
+ revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
+ htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
+ }
+ },
+ _ => return Err(DecodeError::InvalidValue),
+ };
+
+ let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
+ let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
+
+ let their_cur_revocation_points = {
+ let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
+ if first_idx == 0 {
+ None
+ } else {
+ let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let second_point_slice = read_bytes!(33);
+ if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
+ Some((first_idx, first_point, None))
+ } else {
+ Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
+ }
+ }
+ };
+
+ let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
+ let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
+
+ let mut old_secrets = [([0; 32], 1 << 48); 49];
+ for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
+ secret.copy_from_slice(read_bytes!(32));
+ *idx = byte_utils::slice_to_be64(read_bytes!(8));
+ }
+
+ macro_rules! read_htlc_in_commitment {
+ () => {
+ {
+ let offered = match read_bytes!(1)[0] {
+ 0 => false, 1 => true,
+ _ => return Err(DecodeError::InvalidValue),
+ };
+ let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
+ let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
+ let mut payment_hash = [0; 32];
+ payment_hash[..].copy_from_slice(read_bytes!(32));
+ let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
+
+ HTLCOutputInCommitment {
+ offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
+ }
+ }
+ }
+ }
+
+ let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
+ if remote_claimable_outpoints_len > data.len() as u64 / 64 { return Err(DecodeError::BadLengthDescriptor); }
+ let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
+ for _ in 0..remote_claimable_outpoints_len {
+ let txid = Sha256dHash::from(read_bytes!(32));
+ let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
+ if outputs_count > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
+ let mut outputs = Vec::with_capacity(outputs_count as usize);
+ for _ in 0..outputs_count {
+ outputs.push(read_htlc_in_commitment!());
+ }
+ if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
+ return Err(DecodeError::InvalidValue);
+ }
+ }
+
+ let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
+ if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
+ let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
+ for _ in 0..remote_commitment_txn_on_chain_len {
+ let txid = Sha256dHash::from(read_bytes!(32));
+ let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
+ if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
+ return Err(DecodeError::InvalidValue);
+ }
+ }
+
+ let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
+ if remote_hash_commitment_number_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
+ let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
+ for _ in 0..remote_hash_commitment_number_len {
+ let mut txid = [0; 32];
+ txid[..].copy_from_slice(read_bytes!(32));
+ let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
+ if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
+ return Err(DecodeError::InvalidValue);
+ }
+ }
+
+ macro_rules! read_local_tx {
+ () => {
+ {
+ let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
+ let tx_ser = read_bytes!(tx_len);
+ let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
+ if serialize::serialize(&tx).unwrap() != tx_ser {
+ // We check that the tx re-serializes to the same form to ensure there is
+ // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
+ // all that well.
+ return Err(DecodeError::InvalidValue);
+ }
+
+ let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
+ let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
+
+ let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
+ if htlc_outputs_len > data.len() as u64 / 128 { return Err(DecodeError::BadLengthDescriptor); }
+ let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
+ for _ in 0..htlc_outputs_len {
+ htlc_outputs.push((read_htlc_in_commitment!(),
+ unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
+ unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
+ }
+
+ LocalSignedTx {
+ txid: tx.txid(),
+ tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
+ }
+ }
+ }
+ }
+
+ let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
+ 0 => None,
+ 1 => {
+ Some(read_local_tx!())
+ },
+ _ => return Err(DecodeError::InvalidValue),
+ };
+
+ let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
+ 0 => None,
+ 1 => {
+ Some(read_local_tx!())
+ },
+ _ => return Err(DecodeError::InvalidValue),
+ };
+
+ let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
+ if payment_preimages_len > data.len() as u64 / 32 { return Err(DecodeError::InvalidValue); }
+ let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
+ let mut sha = Sha256::new();
+ for _ in 0..payment_preimages_len {
+ let mut preimage = [0; 32];
+ preimage[..].copy_from_slice(read_bytes!(32));
+ sha.reset();
+ sha.input(&preimage);
+ let mut hash = [0; 32];
+ sha.result(&mut hash);
+ if let Some(_) = payment_preimages.insert(hash, preimage) {
+ return Err(DecodeError::InvalidValue);
+ }
+ }
+
+ let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
+ let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
+
+ Ok(ChannelMonitor {
+ funding_txo,
+ commitment_transaction_number_obscure_factor,
+
+ key_storage,
+ delayed_payment_base_key,
+ their_htlc_base_key,
+ their_delayed_payment_base_key,
+ their_cur_revocation_points,
+
+ our_to_self_delay,
+ their_to_self_delay,
+
+ old_secrets,
+ remote_claimable_outpoints,
+ remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
+ remote_hash_commitment_number,
+
+ prev_local_signed_commitment_tx,
+ current_local_signed_commitment_tx,
+
+ payment_preimages,
+
+ destination_script,
+ secp_ctx,
+ })
+ }
+
+}
+
#[cfg(test)]
mod tests {
use bitcoin::blockdata::script::Script;