X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fsign%2Fmod.rs;h=04c4446e2c0c8c75bd4f2f7e3b415b8f35296cf2;hb=34f8dd9a49060676da0cf4157613cfb5fd58cf1e;hp=04652166f05978b6dd8bb1ab0a4b4c2ed9c37d5f;hpb=fa2a2efef47b5da48ac7a239f3d8a835a7f28164;p=rust-lightning

diff --git a/lightning/src/sign/mod.rs b/lightning/src/sign/mod.rs
index 04652166..04c4446e 100644
--- a/lightning/src/sign/mod.rs
+++ b/lightning/src/sign/mod.rs
@@ -107,6 +107,12 @@ impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
 	(12, channel_value_satoshis, required),
 });
 
+pub(crate) const P2WPKH_WITNESS_WEIGHT: u64 = 1 /* num stack items */ +
+	1 /* sig length */ +
+	73 /* sig including sighash flag */ +
+	1 /* pubkey length */ +
+	33 /* pubkey */;
+
 /// Information about a spendable output to our "payment key".
 ///
 /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
@@ -128,6 +134,22 @@ pub struct StaticPaymentOutputDescriptor {
 	pub channel_transaction_parameters: Option<ChannelTransactionParameters>,
 }
 impl StaticPaymentOutputDescriptor {
+	/// Returns the `witness_script` of the spendable output.
+	///
+	/// Note that this will only return `Some` for [`StaticPaymentOutputDescriptor`]s that
+	/// originated from an anchor outputs channel, as they take the form of a P2WSH script.
+	pub fn witness_script(&self) -> Option<Script> {
+		self.channel_transaction_parameters.as_ref()
+			.and_then(|channel_params|
+				 if channel_params.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
+					let payment_point = channel_params.holder_pubkeys.payment_point;
+					Some(chan_utils::get_to_countersignatory_with_anchors_redeemscript(&payment_point))
+				 } else {
+					 None
+				 }
+			)
+	}
+
 	/// The maximum length a well-formed witness spending one of these should have.
 	/// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
 	/// shorter.
@@ -141,9 +163,7 @@ impl StaticPaymentOutputDescriptor {
 			1 /* num witness items */ + 1 /* sig push */ + 73 /* sig including sighash flag */ +
 				1 /* witness script push */ + witness_script_weight
 		} else {
-			// Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
-			// redeemscript push length.
-			1 + 73 + 34
+			P2WPKH_WITNESS_WEIGHT as usize
 		}
 	}
 }
@@ -255,6 +275,9 @@ impl SpendableOutputDescriptor {
 	///
 	/// Note that this does not include any signatures, just the information required to
 	/// construct the transaction and sign it.
+	///
+	/// This is not exported to bindings users as there is no standard serialization for an input.
+	/// See [`Self::create_spendable_outputs_psbt`] instead.
 	pub fn to_psbt_input(&self) -> bitcoin::psbt::Input {
 		match self {
 			SpendableOutputDescriptor::StaticOutput { output, .. } => {
@@ -873,42 +896,68 @@ impl InMemorySigner {
 
 	/// Returns the counterparty's pubkeys.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> {
+		self.get_channel_parameters()
+			.and_then(|params| params.counterparty_parameters.as_ref().map(|params| &params.pubkeys))
+	}
+
 	/// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
 	/// transactions, i.e., the amount of time that we have to wait to recover our funds if we
 	/// broadcast a transaction.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn counterparty_selected_contest_delay(&self) -> Option<u16> {
+		self.get_channel_parameters()
+			.and_then(|params| params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay))
+	}
+
 	/// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
 	/// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
 	/// if they broadcast a transaction.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn holder_selected_contest_delay(&self) -> Option<u16> {
+		self.get_channel_parameters().map(|params| params.holder_selected_contest_delay)
+	}
+
 	/// Returns whether the holder is the initiator.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn is_outbound(&self) -> Option<bool> {
+		self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
+	}
+
 	/// Funding outpoint
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn funding_outpoint(&self) -> Option<&OutPoint> {
+		self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
+	}
+
 	/// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
 	/// building transactions.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
-		self.channel_parameters.as_ref().unwrap()
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> {
+		self.channel_parameters.as_ref()
 	}
+
 	/// Returns the channel type features of the channel parameters. Should be helpful for
 	/// determining a channel's category, i. e. legacy/anchors/taproot/etc.
 	///
-	/// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
-	pub fn channel_type_features(&self) -> &ChannelTypeFeatures {
-		&self.get_channel_parameters().channel_type_features
+	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
+	pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> {
+		self.get_channel_parameters().map(|params| &params.channel_type_features)
 	}
+
 	/// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
 	/// by `descriptor`, returning the witness stack for the input.
 	///
@@ -927,14 +976,20 @@ impl InMemorySigner {
 		if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
 
 		let remotepubkey = bitcoin::PublicKey::new(self.pubkeys().payment_point);
-		let witness_script = if self.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
+		// We cannot always assume that `channel_parameters` is set, so can't just call
+		// `self.channel_parameters()` or anything that relies on it
+		let supports_anchors_zero_fee_htlc_tx = self.channel_type_features()
+			.map(|features| features.supports_anchors_zero_fee_htlc_tx())
+			.unwrap_or(false);
+
+		let witness_script = if supports_anchors_zero_fee_htlc_tx {
 			chan_utils::get_to_countersignatory_with_anchors_redeemscript(&remotepubkey.inner)
 		} else {
 			Script::new_p2pkh(&remotepubkey.pubkey_hash())
 		};
 		let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
 		let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self);
-		let payment_script = if self.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
+		let payment_script = if supports_anchors_zero_fee_htlc_tx {
 			witness_script.to_v0_p2wsh()
 		} else {
 			Script::new_v0_p2wpkh(&remotepubkey.wpubkey_hash().unwrap())
@@ -945,7 +1000,7 @@ impl InMemorySigner {
 		let mut witness = Vec::with_capacity(2);
 		witness.push(remotesig.serialize_der().to_vec());
 		witness[0].push(EcdsaSighashType::All as u8);
-		if self.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
+		if supports_anchors_zero_fee_htlc_tx {
 			witness.push(witness_script.to_bytes());
 		} else {
 			witness.push(remotepubkey.to_bytes());
@@ -1029,13 +1084,16 @@ impl ChannelSigner for InMemorySigner {
 	}
 }
 
+const MISSING_PARAMS_ERR: &'static str = "ChannelSigner::provide_channel_parameters must be called before signing operations";
+
 impl EcdsaChannelSigner for InMemorySigner {
 	fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
 		let trusted_tx = commitment_tx.trust();
 		let keys = trusted_tx.keys();
 
 		let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
-		let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+		let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+		let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
 
 		let built_tx = trusted_tx.built_transaction();
 		let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
@@ -1043,10 +1101,13 @@ impl EcdsaChannelSigner for InMemorySigner {
 
 		let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
 		for htlc in commitment_tx.htlcs() {
-			let channel_parameters = self.get_channel_parameters();
-			let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &channel_parameters.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
-			let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.channel_type_features(), &keys);
-			let htlc_sighashtype = if self.channel_type_features().supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
+			let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
+			let holder_selected_contest_delay =
+				self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
+			let chan_type = &channel_parameters.channel_type_features;
+			let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), holder_selected_contest_delay, htlc, chan_type, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+			let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, chan_type, &keys);
+			let htlc_sighashtype = if chan_type.supports_anchors_zero_fee_htlc_tx() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
 			let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
 			let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
 			htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
@@ -1061,10 +1122,11 @@ impl EcdsaChannelSigner for InMemorySigner {
 
 	fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
 		let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
-		let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+		let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+		let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
 		let trusted_tx = commitment_tx.trust();
 		let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx);
-		let channel_parameters = self.get_channel_parameters();
+		let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
 		let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?;
 		Ok((sig, htlc_sigs))
 	}
@@ -1072,10 +1134,11 @@ impl EcdsaChannelSigner for InMemorySigner {
 	#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
 	fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
 		let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
-		let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+		let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+		let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &counterparty_keys.funding_pubkey);
 		let trusted_tx = commitment_tx.trust();
 		let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx);
-		let channel_parameters = self.get_channel_parameters();
+		let channel_parameters = self.get_channel_parameters().expect(MISSING_PARAMS_ERR);
 		let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?;
 		Ok((sig, htlc_sigs))
 	}
@@ -1085,8 +1148,11 @@ impl EcdsaChannelSigner for InMemorySigner {
 		let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
 		let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
 		let witness_script = {
-			let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint);
-			chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
+			let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+			let holder_selected_contest_delay =
+				self.holder_selected_contest_delay().expect(MISSING_PARAMS_ERR);
+			let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.delayed_payment_basepoint);
+			chan_utils::get_revokeable_redeemscript(&revocation_pubkey, holder_selected_contest_delay, &counterparty_delayedpubkey)
 		};
 		let mut sighash_parts = sighash::SighashCache::new(justice_tx);
 		let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
@@ -1098,9 +1164,11 @@ impl EcdsaChannelSigner for InMemorySigner {
 		let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
 		let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
 		let witness_script = {
-			let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
+			let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+			let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.htlc_basepoint);
 			let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
-			chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.channel_type_features(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
+			let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
+			chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
 		};
 		let mut sighash_parts = sighash::SighashCache::new(justice_tx);
 		let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
@@ -1124,9 +1192,11 @@ impl EcdsaChannelSigner for InMemorySigner {
 	fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
 		let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
 		let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
-		let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
+		let counterparty_keys = self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR);
+		let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &counterparty_keys.htlc_basepoint);
 		let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
-		let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.channel_type_features(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
+		let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
+		let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
 		let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
 		let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
 		Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self))
@@ -1134,7 +1204,8 @@ impl EcdsaChannelSigner for InMemorySigner {
 
 	fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
 		let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
-		let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
+		let counterparty_funding_key = &self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
+		let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, counterparty_funding_key);
 		Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
 	}