Let some tests try to sign a revoked commitment without panic

Return an Err instead so that the test can complete.

Author: devrandom

fuzz/src/chanmon_consistency.rs

@@ -182,7 +182,7 @@ impl KeysInterface for KeyProvider {
 			(0, 0),
 		);
 		let revoked_commitment = self.make_revoked_commitment_cell(keys.commitment_seed);
-		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment)
+		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment, false)
 	}
 
 	fn get_secure_random_bytes(&self) -> [u8; 32] {
@@ -202,6 +202,7 @@ impl KeysInterface for KeyProvider {
 			inner,
 			last_commitment_number: Arc::new(Mutex::new(last_commitment_number)),
 			revoked_commitment,
+			err_on_sign_revoked_holder_tx: false,
 		})
 	}
 }

lightning/src/ln/functional_tests.rs

@@ -7379,7 +7379,10 @@ fn test_data_loss_protect() {
 	let fee_estimator;
 	let tx_broadcaster;
 	let chain_source;
-	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let mut chanmon_cfgs = create_chanmon_cfgs(2);
+	// We broadcast during Drop because chanmon is out of sync with chanmgr, which would cause a panic
+	// during signing due to revoked tx
+	chanmon_cfgs[0].keys_manager.err_on_sign_revoked_holder_tx = true;
 	let keys_manager = &chanmon_cfgs[0].keys_manager;
 	let monitor;
 	let node_state_0;

lightning/src/util/enforcing_trait_impls.rs

@@ -36,22 +36,25 @@ pub struct EnforcingChannelKeys {
 	pub inner: InMemoryChannelKeys,
 	pub last_commitment_number: Arc<Mutex<Option<u64>>>,
 	pub revoked_commitment: Arc<Mutex<u64>>,
+	pub err_on_sign_revoked_holder_tx: bool,
 }
 
 impl EnforcingChannelKeys {
 	pub fn new(inner: InMemoryChannelKeys) -> Self {
 		Self {
 			inner,
 			last_commitment_number: Arc::new(Mutex::new(None)),
-			revoked_commitment: Arc::new(Mutex::new(INITIAL_REVOKED_COMMITMENT_NUMBER))
+			revoked_commitment: Arc::new(Mutex::new(INITIAL_REVOKED_COMMITMENT_NUMBER)),
+			err_on_sign_revoked_holder_tx: false
 		}
 	}
 
-	pub fn new_with_revoked(inner: InMemoryChannelKeys, revoked_commitment: Arc<Mutex<u64>>) -> Self {
+	pub fn new_with_revoked(inner: InMemoryChannelKeys, revoked_commitment: Arc<Mutex<u64>>, err_on_sign_revoked_holder_tx: bool) -> Self {
 		Self {
 			inner,
 			last_commitment_number: Arc::new(Mutex::new(None)),
-			revoked_commitment
+			revoked_commitment,
+			err_on_sign_revoked_holder_tx
 		}
 	}
 }
@@ -100,9 +103,12 @@ impl ChannelKeys for EnforcingChannelKeys {
 		let commitment_number = trusted_tx.commitment_number();
 		println!("XXX sign {} for {}", commitment_number, self.inner.commitment_seed[0]);
 		if *revoked - 1 != commitment_number && *revoked - 2 != commitment_number {
-			println!("can only sign the next two unrevoked commitment numbers, revoked={} vs requested={} for {}",
-			         *revoked, commitment_number, self.inner.commitment_seed[0]);
-			return Err(());
+			if self.err_on_sign_revoked_holder_tx {
+				return Err(());
+			} else {
+				panic!("can only sign the next two unrevoked commitment numbers, revoked={} vs requested={} for {}",
+				       *revoked, commitment_number, self.inner.commitment_seed[0])
+			}
 		}
 
 		for (this_htlc, sig) in trusted_tx.htlcs().iter().zip(&commitment_tx.counterparty_htlc_sigs) {
@@ -165,6 +171,7 @@ impl Readable for EnforcingChannelKeys {
 			inner,
 			last_commitment_number: Arc::new(Mutex::new(last_commitment_number)),
 			revoked_commitment: Arc::new(Mutex::new(INITIAL_REVOKED_COMMITMENT_NUMBER)),
+			err_on_sign_revoked_holder_tx: false,
 		})
 	}
 }

lightning/src/util/test_utils.rs

@@ -422,6 +422,7 @@ pub struct TestKeysInterface {
 	backing: keysinterface::KeysManager,
 	pub override_session_priv: Mutex<Option<[u8; 32]>>,
 	pub override_channel_id_priv: Mutex<Option<[u8; 32]>>,
+	pub err_on_sign_revoked_holder_tx: bool,
 	revoked_commitments: Mutex<HashMap<[u8;32], Arc<Mutex<u64>>>>,
 }
 
@@ -434,7 +435,7 @@ impl keysinterface::KeysInterface for TestKeysInterface {
 	fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> EnforcingChannelKeys {
 		let keys = self.backing.get_channel_keys(inbound, channel_value_satoshis);
 		let revoked_commitment = self.make_revoked_commitment_cell(keys.commitment_seed);
-		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment)
+		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment, self.err_on_sign_revoked_holder_tx)
 	}
 
 	fn get_secure_random_bytes(&self) -> [u8; 32] {
@@ -464,6 +465,7 @@ impl keysinterface::KeysInterface for TestKeysInterface {
 			inner,
 			last_commitment_number: Arc::new(Mutex::new(last_commitment_number)),
 			revoked_commitment,
+			err_on_sign_revoked_holder_tx: self.err_on_sign_revoked_holder_tx,
 		})
 	}
 }
@@ -476,13 +478,14 @@ impl TestKeysInterface {
 			backing: keysinterface::KeysManager::new(seed, network, now.as_secs(), now.subsec_nanos()),
 			override_session_priv: Mutex::new(None),
 			override_channel_id_priv: Mutex::new(None),
+			err_on_sign_revoked_holder_tx: false,
 			revoked_commitments: Mutex::new(HashMap::new()),
 		}
 	}
 	pub fn derive_channel_keys(&self, channel_value_satoshis: u64, user_id_1: u64, user_id_2: u64) -> EnforcingChannelKeys {
 		let keys = self.backing.derive_channel_keys(channel_value_satoshis, user_id_1, user_id_2);
 		let revoked_commitment = self.make_revoked_commitment_cell(keys.commitment_seed);
-		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment)
+		EnforcingChannelKeys::new_with_revoked(keys, revoked_commitment, self.err_on_sign_revoked_holder_tx)
 	}
 
 	fn make_revoked_commitment_cell(&self, commitment_seed: [u8; 32]) -> Arc<Mutex<u64>> {