From b02176c86bfa991a7c4856e427355d6e034e1eaa Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Thu, 19 Jul 2018 17:17:06 -0400 Subject: [PATCH] Fix various spec bugs, can now open channels with real nodes! * commitment transaction number, as used in locktime/sequence fields is actually different from commitment transaction number, as used for revocation state. This is confusing and never stated in the spec, so we have to do the conversion. * max_htlc_value_in_flight is never constrained in the spec, but we were requiring it be <= channel size. Instead just clamp the values the peer sends us when storing. * channel_id calculation was incorrect, we now do some crazy conversion hops, which we shouldn't, but will need to change our types to fix. * Our channel_reserve_satoshis value was too low, just change the constant and leave the TODO to figure out what it really should be for now. --- src/chain/transaction.rs | 6 ++++-- src/ln/channel.rs | 20 +++++++++----------- src/ln/channelmonitor.rs | 2 +- 3 files changed, 14 insertions(+), 14 deletions(-) diff --git a/src/chain/transaction.rs b/src/chain/transaction.rs index dad3c127..42a4f952 100644 --- a/src/chain/transaction.rs +++ b/src/chain/transaction.rs @@ -20,7 +20,9 @@ impl OutPoint { /// Convert an `OutPoint` to a lightning channel id. pub fn to_channel_id(&self) -> Uint256 { - // TODO: or le? - self.txid.into_be() ^ Uint256::from_u64(self.index as u64).unwrap() + let mut index = [0; 32]; + index[30] = ((self.index >> 8) & 0xff) as u8; + index[31] = ((self.index >> 0) & 0xff) as u8; + self.txid.into_le() ^ Sha256dHash::from(&index[..]).into_le() } } diff --git a/src/ln/channel.rs b/src/ln/channel.rs index 93e4a2cf..f36ce1c5 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -245,6 +245,10 @@ pub struct Channel { local_keys: ChannelKeys, + // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction + // generation start at 0 and count up...this simplifies some parts of implementation at the + // cost of others, but should really just be changed. + cur_local_commitment_transaction_number: u64, cur_remote_commitment_transaction_number: u64, value_to_self_msat: u64, // Excluding all pending_htlcs, excluding fees @@ -343,7 +347,7 @@ impl Channel { /// Guaranteed to return a value no larger than channel_value_satoshis fn get_our_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 { - cmp::min(channel_value_satoshis, 10) //TODO + cmp::min(channel_value_satoshis, 1000) //TODO } fn derive_our_dust_limit_satoshis(at_open_background_feerate: u64) -> u64 { @@ -456,9 +460,6 @@ impl Channel { if msg.dust_limit_satoshis > msg.funding_satoshis { return Err(HandleError{err: "Peer never wants payout outputs?", msg: Some(msgs::ErrorAction::DisconnectPeer{})}); } - if msg.max_htlc_value_in_flight_msat > msg.funding_satoshis * 1000 { - return Err(HandleError{err: "Bogus max_htlc_value_in_flight_satoshis", msg: Some(msgs::ErrorAction::DisconnectPeer{})}); - } if msg.htlc_minimum_msat >= (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000 { return Err(HandleError{err: "Minimum htlc value is full channel value", msg: Some(msgs::ErrorAction::DisconnectPeer{})}); } @@ -521,7 +522,7 @@ impl Channel { channel_value_satoshis: msg.funding_satoshis, their_dust_limit_satoshis: msg.dust_limit_satoshis, our_dust_limit_satoshis: Channel::derive_our_dust_limit_satoshis(background_feerate), - their_max_htlc_value_in_flight_msat: msg.max_htlc_value_in_flight_msat, + their_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000), their_channel_reserve_satoshis: msg.channel_reserve_satoshis, their_htlc_minimum_msat: msg.htlc_minimum_msat, our_htlc_minimum_msat: Channel::derive_our_htlc_minimum_msat(msg.feerate_per_kw as u64), @@ -595,7 +596,7 @@ impl Channel { /// which peer generated this transaction and "to whom" this transaction flows. #[inline] fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool) -> (Transaction, Vec) { - let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ commitment_number; + let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (0xffffffffffff - commitment_number); let txins = { let mut ins: Vec = Vec::new(); @@ -1081,9 +1082,6 @@ impl Channel { if msg.dust_limit_satoshis > 21000000 * 100000000 { return Err(HandleError{err: "Peer never wants payout outputs?", msg: None}); } - if msg.max_htlc_value_in_flight_msat > self.channel_value_satoshis * 1000 { - return Err(HandleError{err: "Bogus max_htlc_value_in_flight_satoshis", msg: None}); - } if msg.channel_reserve_satoshis > self.channel_value_satoshis { return Err(HandleError{err: "Bogus channel_reserve_satoshis", msg: None}); } @@ -1101,7 +1099,7 @@ impl Channel { self.channel_monitor.set_their_htlc_base_key(&msg.htlc_basepoint); self.their_dust_limit_satoshis = msg.dust_limit_satoshis; - self.their_max_htlc_value_in_flight_msat = msg.max_htlc_value_in_flight_msat; + self.their_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000); self.their_channel_reserve_satoshis = msg.channel_reserve_satoshis; self.their_htlc_minimum_msat = msg.htlc_minimum_msat; self.their_to_self_delay = msg.to_self_delay; @@ -2407,7 +2405,7 @@ mod tests { macro_rules! test_commitment { ( $their_sig_hex: expr, $our_sig_hex: expr, $tx_hex: expr) => { - unsigned_tx = chan.build_commitment_transaction(42, &keys, true, false); + unsigned_tx = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false); let their_signature = Signature::from_der(&secp_ctx, &hex_bytes($their_sig_hex).unwrap()[..]).unwrap(); let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &chan.get_funding_redeemscript(), chan.channel_value_satoshis)[..]).unwrap(); secp_ctx.verify(&sighash, &their_signature, &chan.their_funding_pubkey).unwrap(); diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index 8c3fcc3f..00b34800 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -910,7 +910,7 @@ impl ChannelMonitor { let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers! let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid); - let commitment_number = (((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor; + let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor); if commitment_number >= self.get_min_seen_secret() { let secret = self.get_secret(commitment_number).unwrap(); let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret)); -- 2.30.2