From: Matt Corallo Date: Mon, 9 Jul 2018 20:40:21 +0000 (-0400) Subject: Implement channelmonitor (de)serialization (fixes #45) X-Git-Tag: v0.0.12~392^2~1 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=0553945e21539f304bef16e8c5c8939e11ee1363;p=rust-lightning Implement channelmonitor (de)serialization (fixes #45) --- diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index 61b0f4557..891dac807 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -1,6 +1,7 @@ use bitcoin::blockdata::block::BlockHeader; use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction}; use bitcoin::blockdata::script::Script; +use bitcoin::network::serialize; use bitcoin::util::hash::Sha256dHash; use bitcoin::util::bip143; @@ -15,6 +16,7 @@ use ln::chan_utils::HTLCOutputInCommitment; use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface}; use chain::transaction::OutPoint; use util::sha2::Sha256; +use util::byte_utils; use std::collections::HashMap; use std::sync::{Arc,Mutex}; @@ -141,6 +143,9 @@ struct LocalSignedTx { htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>, } +const SERIALIZATION_VERSION: u8 = 1; +const MIN_SERIALIZATION_VERSION: u8 = 1; + pub struct ChannelMonitor { funding_txo: Option, commitment_transaction_number_obscure_factor: u64, @@ -439,6 +444,385 @@ impl ChannelMonitor { self.funding_txo } + /// Serializes into a vec, with various modes for the exposed pub fns + fn serialize(&self, for_local_storage: bool) -> Vec { + let mut res = Vec::new(); + res.push(SERIALIZATION_VERSION); + res.push(MIN_SERIALIZATION_VERSION); + + match self.funding_txo { + Some(outpoint) => { + res.extend_from_slice(&outpoint.txid[..]); + res.extend_from_slice(&byte_utils::be16_to_array(outpoint.index)); + }, + None => { + // We haven't even been initialized...not sure why anyone is serializing us, but + // not much to give them. + return res; + }, + } + + // 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)); + + 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[..]); + }, + 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()); + + 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()); + match second_option { + Some(second_pubkey) => { + res.extend_from_slice(&second_pubkey.serialize()); + }, + None => { + res.extend_from_slice(&[0; 33]); + }, + } + }, + None => { + res.extend_from_slice(&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())); + + 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)); + } + + 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)); + } + } + + res.extend_from_slice(&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)); + 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)); + 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)); + } + } + + if for_local_storage { + res.extend_from_slice(&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)); + } + } else { + res.extend_from_slice(&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); + + 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()); + + 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)); + for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() { + serialize_htlc_in_commitment!(htlc_output); + res.extend_from_slice(&their_sig.serialize_compact(&self.secp_ctx)); + res.extend_from_slice(&our_sig.serialize_compact(&self.secp_ctx)); + } + } + } + + if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx { + res.push(1); + serialize_local_tx!(prev_local_tx); + } else { + res.push(0); + } + + if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx { + res.push(1); + serialize_local_tx!(cur_local_tx); + } else { + res.push(0); + } + + res.extend_from_slice(&byte_utils::be64_to_array(self.payment_preimages.len() as u64)); + for payment_preimage in self.payment_preimages.values() { + res.extend_from_slice(payment_preimage); + } + + res.extend_from_slice(&byte_utils::be64_to_array(self.destination_script.len() as u64)); + res.extend_from_slice(&self.destination_script[..]); + + res + } + + /// Encodes this monitor into a byte array, suitable for writing to disk. + pub fn serialize_for_disk(&self) -> Vec { + self.serialize(true) + } + + /// Encodes this monitor into a byte array, suitable for sending to a remote watchtower + pub fn serialize_for_watchtower(&self) -> Vec { + self.serialize(false) + } + + /// Attempts to decode a serialized monitor + pub fn deserialize(data: &[u8]) -> Option { + let mut read_pos = 0; + macro_rules! read_bytes { + ($byte_count: expr) => { + { + if ($byte_count as usize) + read_pos > data.len() { + 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 funding_txo = Some(OutPoint { + txid: Sha256dHash::from(read_bytes!(32)), + index: byte_utils::slice_to_be16(read_bytes!(2)), + }); + 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: Transaction = unwrap_obj!(serialize::deserialize(read_bytes!(tx_len))); + + 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, + }) + } + //TODO: Functions to serialize/deserialize (with different forms depending on which information //we want to leave out (eg funding_txo, etc). diff --git a/src/util/byte_utils.rs b/src/util/byte_utils.rs index 74a01196f..b9ca3f6b6 100644 --- a/src/util/byte_utils.rs +++ b/src/util/byte_utils.rs @@ -11,6 +11,15 @@ pub fn slice_to_be32(v: &[u8]) -> u32 { ((v[3] as u32) << 8*0) } #[inline] +pub fn slice_to_be48(v: &[u8]) -> u64 { + ((v[0] as u64) << 8*5) | + ((v[1] as u64) << 8*4) | + ((v[2] as u64) << 8*3) | + ((v[3] as u64) << 8*2) | + ((v[4] as u64) << 8*1) | + ((v[5] as u64) << 8*0) +} +#[inline] pub fn slice_to_be64(v: &[u8]) -> u64 { ((v[0] as u64) << 8*7) | ((v[1] as u64) << 8*6) | @@ -39,6 +48,18 @@ pub fn be32_to_array(u: u32) -> [u8; 4] { v } #[inline] +pub fn be48_to_array(u: u64) -> [u8; 6] { + assert!(u & 0xffff_0000_0000_0000 == 0); + let mut v = [0; 6]; + v[0] = ((u >> 8*5) & 0xff) as u8; + v[1] = ((u >> 8*4) & 0xff) as u8; + v[2] = ((u >> 8*3) & 0xff) as u8; + v[3] = ((u >> 8*2) & 0xff) as u8; + v[4] = ((u >> 8*1) & 0xff) as u8; + v[5] = ((u >> 8*0) & 0xff) as u8; + v +} +#[inline] pub fn be64_to_array(u: u64) -> [u8; 8] { let mut v = [0; 8]; v[0] = ((u >> 8*7) & 0xff) as u8;