X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannel.rs;h=b678f0f46d798522083dcb145636980899880374;hb=1d3861e5f6a543d882905ebda21656cc0ea231a7;hp=10641d0abbff75aeba310bcdffc1455db54dd18e;hpb=09e167019589dcfc5ee9675ad243b337659eafc7;p=rust-lightning diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 10641d0a..b678f0f4 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -9,15 +9,15 @@ use bitcoin::blockdata::script::{Script,Builder}; use bitcoin::blockdata::transaction::{TxIn, TxOut, Transaction, SigHashType}; -use bitcoin::blockdata::opcodes; use bitcoin::util::bip143; use bitcoin::consensus::encode; use bitcoin::hashes::Hash; use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::hashes::sha256d::Hash as Sha256d; -use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash}; +use bitcoin::hash_types::{Txid, BlockHash}; +use bitcoin::secp256k1::constants::PUBLIC_KEY_SIZE; use bitcoin::secp256k1::key::{PublicKey,SecretKey}; use bitcoin::secp256k1::{Secp256k1,Signature}; use bitcoin::secp256k1; @@ -26,6 +26,7 @@ use ln::{PaymentPreimage, PaymentHash}; use ln::features::{ChannelFeatures, InitFeatures}; use ln::msgs; use ln::msgs::{DecodeError, OptionalField, DataLossProtect}; +use ln::script::ShutdownScript; use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT}; use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor}; use ln::chan_utils; @@ -44,11 +45,11 @@ use util::scid_utils::scid_from_parts; use io; use prelude::*; use core::{cmp,mem,fmt}; +use core::convert::TryFrom; use core::ops::Deref; #[cfg(any(test, feature = "fuzztarget", debug_assertions))] use sync::Mutex; use bitcoin::hashes::hex::ToHex; -use bitcoin::blockdata::opcodes::all::OP_PUSHBYTES_0; #[cfg(test)] pub struct ChannelValueStat { @@ -307,6 +308,7 @@ pub struct CounterpartyForwardingInfo { enum UpdateFulfillFetch { NewClaim { monitor_update: ChannelMonitorUpdate, + htlc_value_msat: u64, msg: Option, }, DuplicateClaim {}, @@ -320,6 +322,8 @@ pub enum UpdateFulfillCommitFetch { NewClaim { /// The ChannelMonitorUpdate which places the new payment preimage in the channel monitor monitor_update: ChannelMonitorUpdate, + /// The value of the HTLC which was claimed, in msat. + htlc_value_msat: u64, /// The update_fulfill message and commitment_signed message (if the claim was not placed /// in the holding cell). msgs: Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, @@ -337,6 +341,9 @@ pub enum UpdateFulfillCommitFetch { // Holder designates channel data owned for the benefice of the user client. // Counterparty designates channel data owned by the another channel participant entity. pub(super) struct Channel { + #[cfg(any(test, feature = "_test_utils"))] + pub(crate) config: ChannelConfig, + #[cfg(not(any(test, feature = "_test_utils")))] config: ChannelConfig, user_id: u64, @@ -349,7 +356,7 @@ pub(super) struct Channel { latest_monitor_update_id: u64, holder_signer: Signer, - shutdown_pubkey: PublicKey, + shutdown_scriptpubkey: Option, destination_script: Script, // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction @@ -567,7 +574,7 @@ impl Channel { } // Constructors: - pub fn new_outbound(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig) -> Result, APIError> + pub fn new_outbound(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures, channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig) -> Result, APIError> where K::Target: KeysInterface, F::Target: FeeEstimator, { @@ -595,6 +602,16 @@ impl Channel { let mut secp_ctx = Secp256k1::new(); secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes()); + let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey { + Some(keys_provider.get_shutdown_scriptpubkey()) + } else { None }; + + if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey { + if !shutdown_scriptpubkey.is_compatible(&their_features) { + return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); + } + } + Ok(Channel { user_id, config: config.channel_options.clone(), @@ -607,7 +624,7 @@ impl Channel { latest_monitor_update_id: 0, holder_signer, - shutdown_pubkey: keys_provider.get_shutdown_pubkey(), + shutdown_scriptpubkey, destination_script: keys_provider.get_destination_script(), cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, @@ -703,7 +720,7 @@ impl Channel { /// Creates a new channel from a remote sides' request for one. /// Assumes chain_hash has already been checked and corresponds with what we expect! - pub fn new_from_req(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig) -> Result, ChannelError> + pub fn new_from_req(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures, msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig) -> Result, ChannelError> where K::Target: KeysInterface, F::Target: FeeEstimator { @@ -823,11 +840,11 @@ impl Channel { // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything if script.len() == 0 { None - // Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. Fail the channel - } else if is_unsupported_shutdown_script(&their_features, script) { - return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided a non-accepted scriptpubkey format. script: ({})", script.to_bytes().to_hex()))); } else { - Some(script.clone()) + match ShutdownScript::try_from((script.clone(), their_features)) { + Ok(shutdown_script) => Some(shutdown_script.into_inner()), + Err(_) => return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))), + } } }, // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel @@ -837,6 +854,16 @@ impl Channel { } } else { None }; + let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey { + Some(keys_provider.get_shutdown_scriptpubkey()) + } else { None }; + + if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey { + if !shutdown_scriptpubkey.is_compatible(&their_features) { + return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); + } + } + let mut secp_ctx = Secp256k1::new(); secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes()); @@ -851,7 +878,7 @@ impl Channel { latest_monitor_update_id: 0, holder_signer, - shutdown_pubkey: keys_provider.get_shutdown_pubkey(), + shutdown_scriptpubkey, destination_script: keys_provider.get_destination_script(), cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, @@ -1130,8 +1157,10 @@ impl Channel { #[inline] fn get_closing_scriptpubkey(&self) -> Script { - let channel_close_key_hash = WPubkeyHash::hash(&self.shutdown_pubkey.serialize()); - Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&channel_close_key_hash[..]).into_script() + // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script + // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method + // outside of those situations will fail. + self.shutdown_scriptpubkey.clone().unwrap().into_inner() } #[inline] @@ -1197,6 +1226,7 @@ impl Channel { }, ())); } + assert!(self.shutdown_scriptpubkey.is_some()); if value_to_self as u64 > self.holder_dust_limit_satoshis { txouts.push((TxOut { script_pubkey: self.get_closing_scriptpubkey(), @@ -1276,6 +1306,7 @@ impl Channel { // these, but for now we just have to treat them as normal. let mut pending_idx = core::usize::MAX; + let mut htlc_value_msat = 0; for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() { if htlc.htlc_id == htlc_id_arg { assert_eq!(htlc.payment_hash, payment_hash_calc); @@ -1295,6 +1326,7 @@ impl Channel { } } pending_idx = idx; + htlc_value_msat = htlc.amount_msat; break; } } @@ -1336,7 +1368,7 @@ impl Channel { // TODO: We may actually be able to switch to a fulfill here, though its // rare enough it may not be worth the complexity burden. debug_assert!(false, "Tried to fulfill an HTLC that was already failed"); - return UpdateFulfillFetch::NewClaim { monitor_update, msg: None }; + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; } }, _ => {} @@ -1348,7 +1380,7 @@ impl Channel { }); #[cfg(any(test, feature = "fuzztarget"))] self.historical_inbound_htlc_fulfills.insert(htlc_id_arg); - return UpdateFulfillFetch::NewClaim { monitor_update, msg: None }; + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; } #[cfg(any(test, feature = "fuzztarget"))] self.historical_inbound_htlc_fulfills.insert(htlc_id_arg); @@ -1358,7 +1390,7 @@ impl Channel { if let InboundHTLCState::Committed = htlc.state { } else { debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); - return UpdateFulfillFetch::NewClaim { monitor_update, msg: None }; + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; } log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id)); htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone())); @@ -1366,6 +1398,7 @@ impl Channel { UpdateFulfillFetch::NewClaim { monitor_update, + htlc_value_msat, msg: Some(msgs::UpdateFulfillHTLC { channel_id: self.channel_id(), htlc_id: htlc_id_arg, @@ -1376,7 +1409,7 @@ impl Channel { pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> Result where L::Target: Logger { match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) { - UpdateFulfillFetch::NewClaim { mut monitor_update, msg: Some(update_fulfill_htlc) } => { + UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg: Some(update_fulfill_htlc) } => { let (commitment, mut additional_update) = match self.send_commitment_no_status_check(logger) { Err(e) => return Err((e, monitor_update)), Ok(res) => res @@ -1385,9 +1418,10 @@ impl Channel { // strictly increasing by one, so decrement it here. self.latest_monitor_update_id = monitor_update.update_id; monitor_update.updates.append(&mut additional_update.updates); - Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, msgs: Some((update_fulfill_htlc, commitment)) }) + Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: Some((update_fulfill_htlc, commitment)) }) }, - UpdateFulfillFetch::NewClaim { monitor_update, msg: None } => Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, msgs: None }), + UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None } => + Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: None }), UpdateFulfillFetch::DuplicateClaim {} => Ok(UpdateFulfillCommitFetch::DuplicateClaim {}), } } @@ -1479,7 +1513,7 @@ impl Channel { // Message handlers: - pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: InitFeatures) -> Result<(), ChannelError> { + pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: &InitFeatures) -> Result<(), ChannelError> { // Check sanity of message fields: if !self.is_outbound() { return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned())); @@ -1550,11 +1584,11 @@ impl Channel { // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything if script.len() == 0 { None - // Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. Fail the channel - } else if is_unsupported_shutdown_script(&their_features, script) { - return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided a non-accepted scriptpubkey format. script: ({})", script.to_bytes().to_hex()))); } else { - Some(script.clone()) + match ShutdownScript::try_from((script.clone(), their_features)) { + Ok(shutdown_script) => Some(shutdown_script.into_inner()), + Err(_) => return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))), + } } }, // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel @@ -1676,8 +1710,9 @@ impl Channel { let funding_redeemscript = self.get_funding_redeemscript(); let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound()); + let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(), - &self.shutdown_pubkey, self.get_holder_selected_contest_delay(), + shutdown_script, self.get_holder_selected_contest_delay(), &self.destination_script, (funding_txo, funding_txo_script.clone()), &self.channel_transaction_parameters, funding_redeemscript.clone(), self.channel_value_satoshis, @@ -1749,8 +1784,9 @@ impl Channel { let funding_txo = self.get_funding_txo().unwrap(); let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound()); + let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(), - &self.shutdown_pubkey, self.get_holder_selected_contest_delay(), + shutdown_script, self.get_holder_selected_contest_delay(), &self.destination_script, (funding_txo, funding_txo_script), &self.channel_transaction_parameters, funding_redeemscript.clone(), self.channel_value_satoshis, @@ -2164,7 +2200,7 @@ impl Channel { /// Marks an outbound HTLC which we have received update_fail/fulfill/malformed #[inline] - fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option, fail_reason: Option) -> Result<&HTLCSource, ChannelError> { + fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option, fail_reason: Option) -> Result<&OutboundHTLCOutput, ChannelError> { for htlc in self.pending_outbound_htlcs.iter_mut() { if htlc.htlc_id == htlc_id { match check_preimage { @@ -2183,13 +2219,13 @@ impl Channel { OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) => return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))), } - return Ok(&htlc.source); + return Ok(htlc); } } Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned())) } - pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result { + pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned())); } @@ -2198,7 +2234,7 @@ impl Channel { } let payment_hash = PaymentHash(Sha256::hash(&msg.payment_preimage.0[..]).into_inner()); - self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|source| source.clone()) + self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat)) } pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> { @@ -2497,7 +2533,7 @@ impl Channel { // in it hitting the holding cell again and we cannot change the state of a // holding cell HTLC from fulfill to anything else. let (update_fulfill_msg_option, mut additional_monitor_update) = - if let UpdateFulfillFetch::NewClaim { msg, monitor_update } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) { + if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) { (msg, monitor_update) } else { unreachable!() }; update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap()); @@ -3081,6 +3117,7 @@ impl Channel { self.channel_state &= !(ChannelState::PeerDisconnected as u32); let shutdown_msg = if self.channel_state & (ChannelState::LocalShutdownSent as u32) != 0 { + assert!(self.shutdown_scriptpubkey.is_some()); Some(msgs::Shutdown { channel_id: self.channel_id, scriptpubkey: self.get_closing_scriptpubkey(), @@ -3192,6 +3229,7 @@ impl Channel { if self.feerate_per_kw > proposed_feerate { proposed_feerate = self.feerate_per_kw; } + assert!(self.shutdown_scriptpubkey.is_some()); let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.counterparty_shutdown_scriptpubkey.as_ref().unwrap())); let proposed_total_fee_satoshis = proposed_feerate as u64 * tx_weight / 1000; @@ -3210,8 +3248,12 @@ impl Channel { }) } - pub fn shutdown(&mut self, fee_estimator: &F, their_features: &InitFeatures, msg: &msgs::Shutdown) -> Result<(Option, Option, Vec<(HTLCSource, PaymentHash)>), ChannelError> - where F::Target: FeeEstimator + pub fn shutdown( + &mut self, fee_estimator: &F, keys_provider: &K, their_features: &InitFeatures, msg: &msgs::Shutdown + ) -> Result<(Option, Option, Option, Vec<(HTLCSource, PaymentHash)>), ChannelError> + where + F::Target: FeeEstimator, + K::Target: KeysInterface { if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish".to_owned())); @@ -3229,23 +3271,58 @@ impl Channel { } assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0); - if is_unsupported_shutdown_script(&their_features, &msg.scriptpubkey) { - return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex()))); - } + let shutdown_scriptpubkey = match ShutdownScript::try_from((msg.scriptpubkey.clone(), their_features)) { + Ok(script) => script.into_inner(), + Err(_) => return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex()))), + }; if self.counterparty_shutdown_scriptpubkey.is_some() { - if Some(&msg.scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() { - return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex()))); + if Some(&shutdown_scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() { + return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", shutdown_scriptpubkey.to_bytes().to_hex()))); } } else { - self.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone()); + self.counterparty_shutdown_scriptpubkey = Some(shutdown_scriptpubkey); } + // If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc + // immediately after the commitment dance, but we can send a Shutdown because we won't send + // any further commitment updates after we set LocalShutdownSent. + let send_shutdown = (self.channel_state & ChannelState::LocalShutdownSent as u32) != ChannelState::LocalShutdownSent as u32; + + let update_shutdown_script = match self.shutdown_scriptpubkey { + Some(_) => false, + None => { + assert!(send_shutdown); + let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey(); + if !shutdown_scriptpubkey.is_compatible(their_features) { + return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); + } + self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); + true + }, + }; + // From here on out, we may not fail! self.channel_state |= ChannelState::RemoteShutdownSent as u32; self.update_time_counter += 1; + let monitor_update = if update_shutdown_script { + self.latest_monitor_update_id += 1; + Some(ChannelMonitorUpdate { + update_id: self.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::ShutdownScript { + scriptpubkey: self.get_closing_scriptpubkey(), + }], + }) + } else { None }; + let shutdown = if send_shutdown { + Some(msgs::Shutdown { + channel_id: self.channel_id, + scriptpubkey: self.get_closing_scriptpubkey(), + }) + } else { None }; + // We can't send our shutdown until we've committed all of our pending HTLCs, but the // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding // cell HTLCs and return them to fail the payment. @@ -3260,23 +3337,11 @@ impl Channel { _ => true } }); - // If we have any LocalAnnounced updates we'll probably just get back a update_fail_htlc - // immediately after the commitment dance, but we can send a Shutdown cause we won't send - // any further commitment updates after we set LocalShutdownSent. - - let shutdown = if (self.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 { - None - } else { - Some(msgs::Shutdown { - channel_id: self.channel_id, - scriptpubkey: self.get_closing_scriptpubkey(), - }) - }; self.channel_state |= ChannelState::LocalShutdownSent as u32; self.update_time_counter += 1; - Ok((shutdown, self.maybe_propose_first_closing_signed(fee_estimator), dropped_outbound_htlcs)) + Ok((shutdown, self.maybe_propose_first_closing_signed(fee_estimator), monitor_update, dropped_outbound_htlcs)) } fn build_signed_closing_transaction(&self, tx: &mut Transaction, counterparty_sig: &Signature, sig: &Signature) { @@ -3351,6 +3416,7 @@ impl Channel { macro_rules! propose_new_feerate { ($new_feerate: expr) => { + assert!(self.shutdown_scriptpubkey.is_some()); let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.counterparty_shutdown_scriptpubkey.as_ref().unwrap())); let (closing_tx, used_total_fee) = self.build_closing_transaction($new_feerate as u64 * tx_weight / 1000, false); let sig = self.holder_signer @@ -3849,7 +3915,10 @@ impl Channel { htlc_basepoint: keys.htlc_basepoint, first_per_commitment_point, channel_flags: if self.config.announced_channel {1} else {0}, - shutdown_scriptpubkey: OptionalField::Present(if self.config.commit_upfront_shutdown_pubkey { self.get_closing_scriptpubkey() } else { Builder::new().into_script() }) + shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey { + Some(script) => script.clone().into_inner(), + None => Builder::new().into_script(), + }), } } @@ -3882,7 +3951,10 @@ impl Channel { delayed_payment_basepoint: keys.delayed_payment_basepoint, htlc_basepoint: keys.htlc_basepoint, first_per_commitment_point, - shutdown_scriptpubkey: OptionalField::Present(if self.config.commit_upfront_shutdown_pubkey { self.get_closing_scriptpubkey() } else { Builder::new().into_script() }) + shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey { + Some(script) => script.clone().into_inner(), + None => Builder::new().into_script(), + }), } } @@ -4390,7 +4462,8 @@ impl Channel { /// Begins the shutdown process, getting a message for the remote peer and returning all /// holding cell HTLCs for payment failure. - pub fn get_shutdown(&mut self) -> Result<(msgs::Shutdown, Vec<(HTLCSource, PaymentHash)>), APIError> { + pub fn get_shutdown(&mut self, keys_provider: &K, their_features: &InitFeatures) -> Result<(msgs::Shutdown, Option, Vec<(HTLCSource, PaymentHash)>), APIError> + where K::Target: KeysInterface { for htlc in self.pending_outbound_htlcs.iter() { if let OutboundHTLCState::LocalAnnounced(_) = htlc.state { return Err(APIError::APIMisuseError{err: "Cannot begin shutdown with pending HTLCs. Process pending events first".to_owned()}); @@ -4409,7 +4482,17 @@ impl Channel { return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()}); } - let closing_script = self.get_closing_scriptpubkey(); + let update_shutdown_script = match self.shutdown_scriptpubkey { + Some(_) => false, + None => { + let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey(); + if !shutdown_scriptpubkey.is_compatible(their_features) { + return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); + } + self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); + true + }, + }; // From here on out, we may not fail! if self.channel_state < ChannelState::FundingSent as u32 { @@ -4419,6 +4502,20 @@ impl Channel { } self.update_time_counter += 1; + let monitor_update = if update_shutdown_script { + self.latest_monitor_update_id += 1; + Some(ChannelMonitorUpdate { + update_id: self.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::ShutdownScript { + scriptpubkey: self.get_closing_scriptpubkey(), + }], + }) + } else { None }; + let shutdown = msgs::Shutdown { + channel_id: self.channel_id, + scriptpubkey: self.get_closing_scriptpubkey(), + }; + // Go ahead and drop holding cell updates as we'd rather fail payments than wait to send // our shutdown until we've committed all of the pending changes. self.holding_cell_update_fee = None; @@ -4433,10 +4530,7 @@ impl Channel { } }); - Ok((msgs::Shutdown { - channel_id: self.channel_id, - scriptpubkey: closing_script, - }, dropped_outbound_htlcs)) + Ok((shutdown, monitor_update, dropped_outbound_htlcs)) } /// Gets the latest commitment transaction and any dependent transactions for relay (forcing @@ -4485,24 +4579,6 @@ impl Channel { } } -fn is_unsupported_shutdown_script(their_features: &InitFeatures, script: &Script) -> bool { - // We restrain shutdown scripts to standards forms to avoid transactions not propagating on the p2p tx-relay network - - // BOLT 2 says we must only send a scriptpubkey of certain standard forms, - // which for a a BIP-141-compliant witness program is at max 42 bytes in length. - // So don't let the remote peer feed us some super fee-heavy script. - let is_script_too_long = script.len() > 42; - if is_script_too_long { - return true; - } - - if their_features.supports_shutdown_anysegwit() && script.is_witness_program() && script.as_bytes()[0] != OP_PUSHBYTES_0.into_u8() { - return false; - } - - return !script.is_p2pkh() && !script.is_p2sh() && !script.is_v0_p2wpkh() && !script.is_v0_p2wsh() -} - const SERIALIZATION_VERSION: u8 = 2; const MIN_SERIALIZATION_VERSION: u8 = 1; @@ -4566,7 +4642,12 @@ impl Writeable for Channel { (key_data.0.len() as u32).write(writer)?; writer.write_all(&key_data.0[..])?; - self.shutdown_pubkey.write(writer)?; + // Write out the old serialization for shutdown_pubkey for backwards compatibility, if + // deserialized from that format. + match self.shutdown_scriptpubkey.as_ref().and_then(|script| script.as_legacy_pubkey()) { + Some(shutdown_pubkey) => shutdown_pubkey.write(writer)?, + None => [0u8; PUBLIC_KEY_SIZE].write(writer)?, + } self.destination_script.write(writer)?; self.cur_holder_commitment_transaction_number.write(writer)?; @@ -4762,6 +4843,7 @@ impl Writeable for Channel { (1, self.minimum_depth, option), (3, self.counterparty_selected_channel_reserve_satoshis, option), (5, self.config, required), + (7, self.shutdown_scriptpubkey, option), }); Ok(()) @@ -4805,7 +4887,11 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel } let holder_signer = keys_source.read_chan_signer(&keys_data)?; - let shutdown_pubkey = Readable::read(reader)?; + // Read the old serialization for shutdown_pubkey, preferring the TLV field later if set. + let mut shutdown_scriptpubkey = match ::read(reader) { + Ok(pubkey) => Some(ShutdownScript::new_p2wpkh_from_pubkey(pubkey)), + Err(_) => None, + }; let destination_script = Readable::read(reader)?; let cur_holder_commitment_transaction_number = Readable::read(reader)?; @@ -4976,6 +5062,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel (1, minimum_depth, option), (3, counterparty_selected_channel_reserve_satoshis, option), (5, config, option), // Note that if none is provided we will *not* overwrite the existing one. + (7, shutdown_scriptpubkey, option), }); let mut secp_ctx = Secp256k1::new(); @@ -4993,7 +5080,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel latest_monitor_update_id, holder_signer, - shutdown_pubkey, + shutdown_scriptpubkey, destination_script, cur_holder_commitment_transaction_number, @@ -5086,6 +5173,7 @@ mod tests { use ln::channel::MAX_FUNDING_SATOSHIS; use ln::features::InitFeatures; use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate}; + use ln::script::ShutdownScript; use ln::chan_utils; use ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT}; use chain::BestBlock; @@ -5094,7 +5182,9 @@ mod tests { use chain::transaction::OutPoint; use util::config::UserConfig; use util::enforcing_trait_impls::EnforcingSigner; + use util::errors::APIError; use util::test_utils; + use util::test_utils::OnGetShutdownScriptpubkey; use util::logger::Logger; use bitcoin::secp256k1::{Secp256k1, Message, Signature, All}; use bitcoin::secp256k1::ffi::Signature as FFISignature; @@ -5103,6 +5193,7 @@ mod tests { use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::hashes::Hash; use bitcoin::hash_types::{Txid, WPubkeyHash}; + use core::num::NonZeroU8; use sync::Arc; use prelude::*; @@ -5135,10 +5226,10 @@ mod tests { Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&channel_monitor_claim_key_hash[..]).into_script() } - fn get_shutdown_pubkey(&self) -> PublicKey { + fn get_shutdown_scriptpubkey(&self) -> ShutdownScript { let secp_ctx = Secp256k1::signing_only(); let channel_close_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(); - PublicKey::from_secret_key(&secp_ctx, &channel_close_key) + ShutdownScript::new_p2wpkh_from_pubkey(PublicKey::from_secret_key(&secp_ctx, &channel_close_key)) } fn get_channel_signer(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemorySigner { @@ -5153,6 +5244,32 @@ mod tests { PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode(hex).unwrap()[..]).unwrap()) } + #[test] + fn upfront_shutdown_script_incompatibility() { + let features = InitFeatures::known().clear_shutdown_anysegwit(); + let non_v0_segwit_shutdown_script = + ShutdownScript::new_witness_program(NonZeroU8::new(16).unwrap(), &[0, 40]).unwrap(); + + let seed = [42; 32]; + let network = Network::Testnet; + let keys_provider = test_utils::TestKeysInterface::new(&seed, network); + keys_provider.expect(OnGetShutdownScriptpubkey { + returns: non_v0_segwit_shutdown_script.clone(), + }); + + let fee_estimator = TestFeeEstimator { fee_est: 253 }; + let secp_ctx = Secp256k1::new(); + let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); + let config = UserConfig::default(); + match Channel::::new_outbound(&&fee_estimator, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config) { + Err(APIError::IncompatibleShutdownScript { script }) => { + assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner()); + }, + Err(e) => panic!("Unexpected error: {:?}", e), + Ok(_) => panic!("Expected error"), + } + } + // Check that, during channel creation, we use the same feerate in the open channel message // as we do in the Channel object creation itself. #[test] @@ -5166,7 +5283,7 @@ mod tests { let node_a_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let config = UserConfig::default(); - let node_a_chan = Channel::::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, 10000000, 100000, 42, &config).unwrap(); + let node_a_chan = Channel::::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap(); // Now change the fee so we can check that the fee in the open_channel message is the // same as the old fee. @@ -5191,18 +5308,18 @@ mod tests { // Create Node A's channel pointing to Node B's pubkey let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let config = UserConfig::default(); - let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, 10000000, 100000, 42, &config).unwrap(); + let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap(); // Create Node B's channel by receiving Node A's open_channel message // Make sure A's dust limit is as we expect. let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash()); let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap()); - let node_b_chan = Channel::::new_from_req(&&feeest, &&keys_provider, node_b_node_id, InitFeatures::known(), &open_channel_msg, 7, &config).unwrap(); + let node_b_chan = Channel::::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config).unwrap(); // Node B --> Node A: accept channel, explicitly setting B's dust limit. let mut accept_channel_msg = node_b_chan.get_accept_channel(); accept_channel_msg.dust_limit_satoshis = 546; - node_a_chan.accept_channel(&accept_channel_msg, &config, InitFeatures::known()).unwrap(); + node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap(); node_a_chan.holder_dust_limit_satoshis = 1560; // Put some inbound and outbound HTLCs in A's channel. @@ -5258,7 +5375,7 @@ mod tests { let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let config = UserConfig::default(); - let mut chan = Channel::::new_outbound(&&fee_est, &&keys_provider, node_id, 10000000, 100000, 42, &config).unwrap(); + let mut chan = Channel::::new_outbound(&&fee_est, &&keys_provider, node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap(); let commitment_tx_fee_0_htlcs = chan.commit_tx_fee_msat(0); let commitment_tx_fee_1_htlc = chan.commit_tx_fee_msat(1); @@ -5307,16 +5424,16 @@ mod tests { // Create Node A's channel pointing to Node B's pubkey let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let config = UserConfig::default(); - let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, 10000000, 100000, 42, &config).unwrap(); + let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap(); // Create Node B's channel by receiving Node A's open_channel message let open_channel_msg = node_a_chan.get_open_channel(chain_hash); let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap()); - let mut node_b_chan = Channel::::new_from_req(&&feeest, &&keys_provider, node_b_node_id, InitFeatures::known(), &open_channel_msg, 7, &config).unwrap(); + let mut node_b_chan = Channel::::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config).unwrap(); // Node B --> Node A: accept channel let accept_channel_msg = node_b_chan.get_accept_channel(); - node_a_chan.accept_channel(&accept_channel_msg, &config, InitFeatures::known()).unwrap(); + node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap(); // Node A --> Node B: funding created let output_script = node_a_chan.get_funding_redeemscript(); @@ -5369,7 +5486,7 @@ mod tests { // Create a channel. let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let config = UserConfig::default(); - let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, 10000000, 100000, 42, &config).unwrap(); + let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap(); assert!(node_a_chan.counterparty_forwarding_info.is_none()); assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1); // the default assert!(node_a_chan.counterparty_forwarding_info().is_none()); @@ -5433,7 +5550,7 @@ mod tests { let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); let mut config = UserConfig::default(); config.channel_options.announced_channel = false; - let mut chan = Channel::::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, 10_000_000, 100000, 42, &config).unwrap(); // Nothing uses their network key in this test + let mut chan = Channel::::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config).unwrap(); // Nothing uses their network key in this test chan.holder_dust_limit_satoshis = 546; chan.counterparty_selected_channel_reserve_satoshis = Some(0); // Filled in in accept_channel