+
+ /// Marks an inbound channel as accepted and generates a [`msgs::AcceptChannel`] message which
+ /// should be sent back to the counterparty node.
+ ///
+ /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
+ pub fn accept_inbound_channel(&mut self) -> msgs::AcceptChannel {
+ if self.context.is_outbound() {
+ panic!("Tried to send accept_channel for an outbound channel?");
+ }
+ if self.context.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) {
+ panic!("Tried to send accept_channel after channel had moved forward");
+ }
+ if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+ panic!("Tried to send an accept_channel for a channel that has already advanced");
+ }
+
+ self.generate_accept_channel_message()
+ }
+
+ /// This function is used to explicitly generate a [`msgs::AcceptChannel`] message for an
+ /// inbound channel. If the intention is to accept an inbound channel, use
+ /// [`InboundV1Channel::accept_inbound_channel`] instead.
+ ///
+ /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
+ fn generate_accept_channel_message(&self) -> msgs::AcceptChannel {
+ let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx);
+ let keys = self.context.get_holder_pubkeys();
+
+ msgs::AcceptChannel {
+ temporary_channel_id: self.context.channel_id,
+ dust_limit_satoshis: self.context.holder_dust_limit_satoshis,
+ max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat,
+ channel_reserve_satoshis: self.context.holder_selected_channel_reserve_satoshis,
+ htlc_minimum_msat: self.context.holder_htlc_minimum_msat,
+ minimum_depth: self.context.minimum_depth.unwrap(),
+ to_self_delay: self.context.get_holder_selected_contest_delay(),
+ max_accepted_htlcs: self.context.holder_max_accepted_htlcs,
+ funding_pubkey: keys.funding_pubkey,
+ revocation_basepoint: keys.revocation_basepoint,
+ payment_point: keys.payment_point,
+ delayed_payment_basepoint: keys.delayed_payment_basepoint,
+ htlc_basepoint: keys.htlc_basepoint,
+ first_per_commitment_point,
+ shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey {
+ Some(script) => script.clone().into_inner(),
+ None => Builder::new().into_script(),
+ }),
+ channel_type: Some(self.context.channel_type.clone()),
+ #[cfg(taproot)]
+ next_local_nonce: None,
+ }
+ }
+
+ /// Enables the possibility for tests to extract a [`msgs::AcceptChannel`] message for an
+ /// inbound channel without accepting it.
+ ///
+ /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
+ #[cfg(test)]
+ pub fn get_accept_channel_message(&self) -> msgs::AcceptChannel {
+ self.generate_accept_channel_message()
+ }
+
+ fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(CommitmentTransaction, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
+ let funding_script = self.context.get_funding_redeemscript();
+
+ let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number);
+ let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
+ {
+ let trusted_tx = initial_commitment_tx.trust();
+ let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
+ let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis);
+ // They sign the holder commitment transaction...
+ log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
+ log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()),
+ encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
+ encode::serialize_hex(&funding_script), &self.context.channel_id());
+ secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
+ }
+
+ let counterparty_keys = self.context.build_remote_transaction_keys();
+ let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
+
+ let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
+ let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
+ log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
+ &self.context.channel_id(), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
+
+ match &self.context.holder_signer {
+ // TODO (arik): move match into calling method for Taproot
+ ChannelSignerType::Ecdsa(ecdsa) => {
+ let counterparty_signature = ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
+ .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0;
+
+ // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
+ Ok((counterparty_initial_commitment_tx, initial_commitment_tx, counterparty_signature))
+ }
+ }
+ }
+
+ pub fn funding_created<L: Deref>(
+ mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L
+ ) -> Result<(Channel<SP>, msgs::FundingSigned, ChannelMonitor<<SP::Target as SignerProvider>::Signer>), (Self, ChannelError)>
+ where
+ L::Target: Logger
+ {
+ if self.context.is_outbound() {
+ return Err((self, ChannelError::Close("Received funding_created for an outbound channel?".to_owned())));
+ }
+ if self.context.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
+ // BOLT 2 says that if we disconnect before we send funding_signed we SHOULD NOT
+ // remember the channel, so it's safe to just send an error_message here and drop the
+ // channel.
+ return Err((self, ChannelError::Close("Received funding_created after we got the channel!".to_owned())));
+ }
+ if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
+ self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
+ self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+ panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
+ }
+
+ let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index };
+ self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
+ // This is an externally observable change before we finish all our checks. In particular
+ // funding_created_signature may fail.
+ self.context.holder_signer.as_mut().provide_channel_parameters(&self.context.channel_transaction_parameters);
+
+ let (counterparty_initial_commitment_tx, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) {
+ Ok(res) => res,
+ Err(ChannelError::Close(e)) => {
+ self.context.channel_transaction_parameters.funding_outpoint = None;
+ return Err((self, ChannelError::Close(e)));
+ },
+ Err(e) => {
+ // The only error we know how to handle is ChannelError::Close, so we fall over here
+ // to make sure we don't continue with an inconsistent state.
+ panic!("unexpected error type from funding_created_signature {:?}", e);
+ }
+ };
+
+ let holder_commitment_tx = HolderCommitmentTransaction::new(
+ initial_commitment_tx,
+ msg.signature,
+ Vec::new(),
+ &self.context.get_holder_pubkeys().funding_pubkey,
+ self.context.counterparty_funding_pubkey()
+ );
+
+ if let Err(_) = self.context.holder_signer.as_ref().validate_holder_commitment(&holder_commitment_tx, Vec::new()) {
+ return Err((self, ChannelError::Close("Failed to validate our commitment".to_owned())));
+ }
+
+ // Now that we're past error-generating stuff, update our local state:
+
+ let funding_redeemscript = self.context.get_funding_redeemscript();
+ let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
+ let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound());
+ let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
+ let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id);
+ monitor_signer.provide_channel_parameters(&self.context.channel_transaction_parameters);
+ let channel_monitor = ChannelMonitor::new(self.context.secp_ctx.clone(), monitor_signer,
+ shutdown_script, self.context.get_holder_selected_contest_delay(),
+ &self.context.destination_script, (funding_txo, funding_txo_script.clone()),
+ &self.context.channel_transaction_parameters,
+ funding_redeemscript.clone(), self.context.channel_value_satoshis,
+ obscure_factor,
+ holder_commitment_tx, best_block, self.context.counterparty_node_id);
+
+ channel_monitor.provide_initial_counterparty_commitment_tx(
+ counterparty_initial_commitment_tx.trust().txid(), Vec::new(),
+ self.context.cur_counterparty_commitment_transaction_number,
+ self.context.counterparty_cur_commitment_point.unwrap(), self.context.feerate_per_kw,
+ counterparty_initial_commitment_tx.to_broadcaster_value_sat(),
+ counterparty_initial_commitment_tx.to_countersignatory_value_sat(), logger);
+
+ self.context.channel_state = ChannelState::FundingSent as u32;
+ self.context.channel_id = funding_txo.to_channel_id();
+ self.context.cur_counterparty_commitment_transaction_number -= 1;
+ self.context.cur_holder_commitment_transaction_number -= 1;
+
+ log_info!(logger, "Generated funding_signed for peer for channel {}", &self.context.channel_id());
+
+ // Promote the channel to a full-fledged one now that we have updated the state and have a
+ // `ChannelMonitor`.
+ let mut channel = Channel {
+ context: self.context,
+ };
+ let channel_id = channel.context.channel_id.clone();
+ let need_channel_ready = channel.check_get_channel_ready(0).is_some();
+ channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new());
+
+ Ok((channel, msgs::FundingSigned {
+ channel_id,
+ signature,
+ #[cfg(taproot)]
+ partial_signature_with_nonce: None,
+ }, channel_monitor))
+ }