From 90b0ed937e32c31efb219d4cb19a613aa104a412 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 19 Nov 2018 17:12:17 -0500 Subject: [PATCH] Provide commitment point to monitor with the remote txn update This extends 1b33064554ae48c9173acf8bf1e0052d33a855df by re-simplifying the ChannelMonitor <-> Channel interface a bit as we never have any use for the latest remote commitment point until we have knowledge of a remote transaction generated using it. --- src/ln/channel.rs | 10 +++---- src/ln/channelmonitor.rs | 57 ++++++++++++++++++---------------------- 2 files changed, 28 insertions(+), 39 deletions(-) diff --git a/src/ln/channel.rs b/src/ln/channel.rs index e60f5628e..e0fdcaf90 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -633,7 +633,6 @@ impl Channel { &chan_keys.htlc_base_key, &chan_keys.payment_base_key, &keys_provider.get_shutdown_pubkey(), BREAKDOWN_TIMEOUT, keys_provider.get_destination_script(), logger.clone()); channel_monitor.set_their_base_keys(&msg.htlc_basepoint, &msg.delayed_payment_basepoint); - channel_monitor.provide_their_next_revocation_point(Some((INITIAL_COMMITMENT_NUMBER, msg.first_per_commitment_point))); channel_monitor.set_their_to_self_delay(msg.to_self_delay); let mut chan = Channel { @@ -1358,7 +1357,6 @@ impl Channel { } self.channel_monitor.set_their_base_keys(&msg.htlc_basepoint, &msg.delayed_payment_basepoint); - self.channel_monitor.provide_their_next_revocation_point(Some((INITIAL_COMMITMENT_NUMBER, msg.first_per_commitment_point))); self.their_dust_limit_satoshis = msg.dust_limit_satoshis; self.their_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000); @@ -1434,7 +1432,7 @@ impl Channel { // Now that we're past error-generating stuff, update our local state: - self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number); + self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap()); self.last_local_commitment_txn = vec![local_initial_commitment_tx.clone()]; self.channel_monitor.provide_latest_local_commitment_tx_info(local_initial_commitment_tx, local_keys, self.feerate_per_kw, Vec::new()); self.channel_state = ChannelState::FundingSent as u32; @@ -1506,7 +1504,6 @@ impl Channel { return Err(ChannelError::Close("Peer sent a funding_locked at a strange time")); } - self.channel_monitor.provide_their_next_revocation_point(Some((INITIAL_COMMITMENT_NUMBER - 1 , msg.next_per_commitment_point))); self.their_prev_commitment_point = self.their_cur_commitment_point; self.their_cur_commitment_point = Some(msg.next_per_commitment_point); Ok(()) @@ -1901,7 +1898,6 @@ impl Channel { } self.channel_monitor.provide_secret(self.cur_remote_commitment_transaction_number + 1, msg.per_commitment_secret) .map_err(|e| ChannelError::Close(e.0))?; - self.channel_monitor.provide_their_next_revocation_point(Some((self.cur_remote_commitment_transaction_number - 1, msg.next_per_commitment_point))); // Update state now that we've passed all the can-fail calls... // (note that we may still fail to generate the new commitment_signed message, but that's @@ -3002,7 +2998,7 @@ impl Channel { let temporary_channel_id = self.channel_id; // Now that we're past error-generating stuff, update our local state: - self.channel_monitor.provide_latest_remote_commitment_tx_info(&commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number); + self.channel_monitor.provide_latest_remote_commitment_tx_info(&commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap()); self.channel_state = ChannelState::FundingCreated as u32; self.channel_id = funding_txo.to_channel_id(); self.cur_remote_commitment_transaction_number -= 1; @@ -3214,7 +3210,7 @@ impl Channel { match self.send_commitment_no_state_update() { Ok((res, remote_commitment_tx)) => { // Update state now that we've passed all the can-fail calls... - self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_commitment_tx.0, remote_commitment_tx.1, self.cur_remote_commitment_transaction_number); + self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_commitment_tx.0, remote_commitment_tx.1, self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap()); self.channel_state |= ChannelState::AwaitingRemoteRevoke as u32; Ok((res, self.channel_monitor.clone())) }, diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index d50c73f6d..39eba2198 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -461,37 +461,11 @@ impl ChannelMonitor { Ok(()) } - /// Tracks the next revocation point which may be required to claim HTLC outputs which we know - /// the preimage of in case the remote end force-closes using their latest state. When called at - /// channel opening revocation point is the CURRENT one used for first commitment tx. Needed in case of sizeable push_msat. - pub(super) fn provide_their_next_revocation_point(&mut self, their_next_revocation_point: Option<(u64, PublicKey)>) { - if let Some(new_revocation_point) = their_next_revocation_point { - match self.their_cur_revocation_points { - Some(old_points) => { - if old_points.0 == new_revocation_point.0 + 1 { - self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1))); - } else if old_points.0 == new_revocation_point.0 + 2 { - if let Some(old_second_point) = old_points.2 { - self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1))); - } else { - self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None)); - } - } else { - self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None)); - } - }, - None => { - self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None)); - } - } - } - } - /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction. /// The monitor watches for it to be broadcasted and then uses the HTLC information (and /// possibly future revocation/preimage information) to claim outputs where possible. /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers. - pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec, commitment_number: u64) { + pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec, commitment_number: u64, their_revocation_point: PublicKey) { // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction // so that a remote monitor doesn't learn anything unless there is a malicious close. // (only maybe, sadly we cant do the same for local info, as we need to be aware of @@ -501,6 +475,25 @@ impl ChannelMonitor { } self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs); self.current_remote_commitment_number = commitment_number; + //TODO: Merge this into the other per-remote-transaction output storage stuff + match self.their_cur_revocation_points { + Some(old_points) => { + if old_points.0 == commitment_number + 1 { + self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point))); + } else if old_points.0 == commitment_number + 2 { + if let Some(old_second_point) = old_points.2 { + self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point))); + } else { + self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None)); + } + } else { + self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None)); + } + }, + None => { + self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None)); + } + } } /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The @@ -2161,10 +2154,10 @@ mod tests { let logger = Arc::new(TestLogger::new()); let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap(); + let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap()); macro_rules! dummy_keys { () => { { - let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap()); TxCreationKeys { per_commitment_point: dummy_key.clone(), revocation_key: dummy_key.clone(), @@ -2233,10 +2226,10 @@ mod tests { monitor.set_their_to_self_delay(10); monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10])); - monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655); - monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654); - monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653); - monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652); + monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key); + monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key); + monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key); + monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key); for &(ref preimage, ref hash) in preimages.iter() { monitor.provide_payment_preimage(hash, preimage); } -- 2.39.5