fixup: Add method to derive Peer Storage encryption key

Author: adi2011

fuzz/src/chanmon_consistency.rs

@@ -37,6 +37,7 @@ use lightning::blinded_path::message::{BlindedMessagePath, MessageContext};
 use lightning::blinded_path::payment::{BlindedPaymentPath, ReceiveTlvs};
 use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
+use lightning::chain::chainmonitor::PeerStorageKey;
 use lightning::chain::channelmonitor::{ChannelMonitor, MonitorEvent};
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::{
@@ -338,8 +339,8 @@ impl NodeSigner for KeyProvider {
 		unreachable!()
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
-		SecretKey::from_slice(&[42; 32]).unwrap().secret_bytes()
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
+		PeerStorageKey::new(&[42; 32])
 	}
 
 	fn sign_bolt12_invoice(

fuzz/src/full_stack.rs

@@ -34,7 +34,7 @@ use lightning::blinded_path::message::{BlindedMessagePath, MessageContext};
 use lightning::blinded_path::payment::{BlindedPaymentPath, ReceiveTlvs};
 use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
-use lightning::chain::chainmonitor;
+use lightning::chain::chainmonitor::{self, PeerStorageKey};
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::{BestBlock, ChannelMonitorUpdateStatus, Confirm, Listen};
 use lightning::events::Event;
@@ -422,8 +422,8 @@ impl NodeSigner for KeyProvider {
 		Ok(secp_ctx.sign_ecdsa(&msg_hash, &self.node_secret))
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
-		SecretKey::from_slice(&[42; 32]).unwrap().secret_bytes()
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
+		PeerStorageKey::new(&[42; 32])
 	}
 }
 

fuzz/src/onion_message.rs

@@ -9,6 +9,7 @@ use lightning::blinded_path::message::{
 	AsyncPaymentsContext, BlindedMessagePath, MessageContext, OffersContext,
 };
 use lightning::blinded_path::EmptyNodeIdLookUp;
+use lightning::chain::chainmonitor::PeerStorageKey;
 use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::ln::msgs::{self, BaseMessageHandler, DecodeError, OnionMessageHandler};
 use lightning::ln::peer_handler::IgnoringMessageHandler;
@@ -250,7 +251,7 @@ impl NodeSigner for KeyProvider {
 		unreachable!()
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
 		unreachable!()
 	}
 }

lightning/src/chain/chainmonitor.rs

@@ -218,7 +218,21 @@ impl<ChannelSigner: EcdsaChannelSigner> Deref for LockedChannelMonitor<'_, Chann
 }
 
 /// Represents Secret Key used for encrypting Peer Storage.
-type PeerStorageKey = [u8; 32];
+#[derive(Clone, PartialEq, Eq)]
+pub struct PeerStorageKey ([u8; 32]);
+
+impl PeerStorageKey {
+	/// Creates a new `PeerStorageKey` from a `[u8; 32]` array.
+    pub fn new(key: [u8; 32]) -> Self {
+        PeerStorageKey(key)
+    }
+
+    /// Returns a reference to the inner `[u8; 32]` array.
+    pub fn as_bytes(&self) -> &[u8; 32] {
+        &self.0
+    }
+}
+
 
 /// An implementation of [`chain::Watch`] for monitoring channels.
 ///

lightning/src/ln/blinded_payment_tests.rs

@@ -18,6 +18,7 @@ use crate::blinded_path::utils::is_padded;
 use crate::events::{Event, HTLCDestination, PaymentFailureReason};
 use crate::ln::types::ChannelId;
 use crate::types::payment::{PaymentHash, PaymentSecret};
+use crate::chain::chainmonitor::PeerStorageKey;
 use crate::ln::channelmanager;
 use crate::ln::channelmanager::{HTLCFailureMsg, PaymentId, RecipientOnionFields};
 use crate::types::features::{BlindedHopFeatures, ChannelFeatures, NodeFeatures};
@@ -1609,7 +1610,7 @@ fn route_blinding_spec_test_vector() {
 		fn sign_invoice(
 			&self, _invoice: &RawBolt11Invoice, _recipient: Recipient,
 		) -> Result<RecoverableSignature, ()> { unreachable!() }
-		fn get_peer_storage_key(&self) -> [u8; 32] { unreachable!() }
+		fn get_peer_storage_key(&self) -> PeerStorageKey { unreachable!() }
 		fn sign_bolt12_invoice(
 			&self, _invoice: &UnsignedBolt12Invoice,
 		) -> Result<schnorr::Signature, ()> { unreachable!() }
@@ -1919,7 +1920,7 @@ fn test_trampoline_inbound_payment_decoding() {
 		fn sign_invoice(
 			&self, _invoice: &RawBolt11Invoice, _recipient: Recipient,
 		) -> Result<RecoverableSignature, ()> { unreachable!() }
-		fn get_peer_storage_key(&self) -> [u8; 32] { unreachable!() }
+		fn get_peer_storage_key(&self) -> PeerStorageKey { unreachable!() }
 		fn sign_bolt12_invoice(
 			&self, _invoice: &UnsignedBolt12Invoice,
 		) -> Result<schnorr::Signature, ()> { unreachable!() }

lightning/src/ln/channelmanager.rs

@@ -16362,7 +16362,7 @@ mod tests {
 #[cfg(ldk_bench)]
 pub mod bench {
 	use crate::chain::Listen;
-	use crate::chain::chainmonitor::{ChainMonitor, Persist};
+	use crate::chain::chainmonitor::{ChainMonitor, PeerStorageKey, Persist};
 	use crate::sign::{KeysManager, InMemorySigner, NodeSigner};
 	use crate::events::Event;
 	use crate::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, PaymentHash, PaymentPreimage, PaymentId, RecipientOnionFields, Retry};

lightning/src/sign/mod.rs

@@ -37,6 +37,7 @@ use bitcoin::{secp256k1, Psbt, Sequence, Txid, WPubkeyHash, Witness};
 
 use lightning_invoice::RawBolt11Invoice;
 
+use crate::chain::chainmonitor::PeerStorageKey;
 use crate::chain::transaction::OutPoint;
 use crate::crypto::utils::{hkdf_extract_expand_twice, sign, sign_with_aux_rand};
 use crate::ln::chan_utils;
@@ -839,7 +840,7 @@ pub trait NodeSigner {
 	///
 	/// Thus, if you wish to rely on recovery using this method, you should use a key which
 	/// can be re-derived from data which would be available after state loss (eg the wallet seed)
-	fn get_peer_storage_key(&self) -> [u8; 32];
+	fn get_peer_storage_key(&self) -> PeerStorageKey;
 
 	/// Get node id based on the provided [`Recipient`].
 	///
@@ -1780,7 +1781,7 @@ pub struct KeysManager {
 	shutdown_pubkey: PublicKey,
 	channel_master_key: Xpriv,
 	channel_child_index: AtomicUsize,
-	peer_storage_key: SecretKey,
+	peer_storage_key: PeerStorageKey,
 
 	#[cfg(test)]
 	pub(crate) entropy_source: RandomBytes,
@@ -1890,7 +1891,7 @@ impl KeysManager {
 					node_id,
 					inbound_payment_key: ExpandedKey::new(inbound_pmt_key_bytes),
 
-					peer_storage_key,
+					peer_storage_key: PeerStorageKey::new(peer_storage_key.secret_bytes()),
 
 					destination_script,
 					shutdown_pubkey,
@@ -2117,8 +2118,8 @@ impl NodeSigner for KeysManager {
 		self.inbound_payment_key.clone()
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
-		self.peer_storage_key.secret_bytes()
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
+		self.peer_storage_key.clone()
 	}
 
 	fn sign_invoice(
@@ -2282,8 +2283,8 @@ impl NodeSigner for PhantomKeysManager {
 		self.inbound_payment_key.clone()
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
-		self.inner.peer_storage_key.secret_bytes()
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
+		self.inner.peer_storage_key.clone()
 	}
 
 	fn sign_invoice(

lightning/src/util/dyn_signer.rs

@@ -4,6 +4,7 @@ use crate::prelude::*;
 
 use core::any::Any;
 
+use crate::chain::chainmonitor::PeerStorageKey;
 use crate::ln::chan_utils::{
 	ChannelPublicKeys, ChannelTransactionParameters, ClosingTransaction, CommitmentTransaction,
 	HTLCOutputInCommitment, HolderCommitmentTransaction,
@@ -215,7 +216,7 @@ inner,
 		invoice: &crate::offers::invoice::UnsignedBolt12Invoice
 	) -> Result<secp256k1::schnorr::Signature, ()>,
 	fn get_inbound_payment_key(,) -> ExpandedKey,
-	fn get_peer_storage_key(,) -> [u8; 32]
+	fn get_peer_storage_key(,) -> PeerStorageKey
 );
 
 delegate!(DynKeysInterface, SignerProvider,
@@ -284,7 +285,7 @@ delegate!(DynPhantomKeysInterface, NodeSigner,
 	fn sign_bolt12_invoice(, invoice: &crate::offers::invoice::UnsignedBolt12Invoice
 	) -> Result<secp256k1::schnorr::Signature, ()>,
 	fn get_inbound_payment_key(,) -> ExpandedKey,
-	fn get_peer_storage_key(,) -> [u8; 32]
+	fn get_peer_storage_key(,) -> PeerStorageKey
 );
 
 impl SignerProvider for DynPhantomKeysInterface {

lightning/src/util/test_utils.rs

@@ -15,7 +15,7 @@ use crate::chain::chaininterface;
 use crate::chain::chaininterface::ConfirmationTarget;
 #[cfg(any(test, feature = "_externalize_tests"))]
 use crate::chain::chaininterface::FEERATE_FLOOR_SATS_PER_KW;
-use crate::chain::chainmonitor::{ChainMonitor, Persist};
+use crate::chain::chainmonitor::{ChainMonitor, PeerStorageKey, Persist};
 use crate::chain::channelmonitor::{
 	ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, MonitorEvent,
 };
@@ -1452,7 +1452,7 @@ impl NodeSigner for TestNodeSigner {
 		unreachable!()
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
 		unreachable!()
 	}
 
@@ -1534,7 +1534,7 @@ impl NodeSigner for TestKeysInterface {
 		self.backing.sign_invoice(invoice, recipient)
 	}
 
-	fn get_peer_storage_key(&self) -> [u8; 32] {
+	fn get_peer_storage_key(&self) -> PeerStorageKey {
 		self.backing.get_peer_storage_key()
 	}