Explcitely link commit tx changes to the actual commit tx outputs

We currently don't have a link between commitment specs and the resulting commit tx output, and instead we try and match pubkey scripts to find which commit tx output to attach to a spending tx. Instead here we create explicit links between commitment spec items and commit tx outputs (basically a list of (spec item, tx output) than we can then sort, and use to build the commit tx. We then know that the nth output in our commit tx was built from the nth element in our (spec item, tx output) sorted list.
ACINQ · Sep 30, 2019 · 2f97a5c · 2f97a5c
1 parent 19480e2
commit 2f97a5c
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Showing 5 changed files with 180 additions and 93 deletions.
diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/channel/Commitments.scala b/eclair-core/src/main/scala/fr/acinq/eclair/channel/Commitments.scala
@@ -536,27 +536,41 @@ object Commitments {
     }
   }
 
-  def makeLocalTxs(keyManager: KeyManager, channelVersion: ChannelVersion, commitTxNumber: Long, localParams: LocalParams, remoteParams: RemoteParams, commitmentInput: InputInfo, localPerCommitmentPoint: PublicKey, spec: CommitmentSpec): (CommitTx, Seq[HtlcTimeoutTx], Seq[HtlcSuccessTx]) = {
+  def makeLocalTxs(keyManager: KeyManager,
+                   channelVersion: ChannelVersion,
+                   commitTxNumber: Long,
+                   localParams: LocalParams,
+                   remoteParams: RemoteParams,
+                   commitmentInput: InputInfo,
+                   localPerCommitmentPoint: PublicKey,
+                   spec: CommitmentSpec): (CommitTx, Seq[HtlcTimeoutTx], Seq[HtlcSuccessTx]) = {
     val channelKeyPath = keyManager.channelKeyPath(localParams, channelVersion)
     val localDelayedPaymentPubkey = Generators.derivePubKey(keyManager.delayedPaymentPoint(channelKeyPath).publicKey, localPerCommitmentPoint)
     val localHtlcPubkey = Generators.derivePubKey(keyManager.htlcPoint(channelKeyPath).publicKey, localPerCommitmentPoint)
     val remotePaymentPubkey = Generators.derivePubKey(remoteParams.paymentBasepoint, localPerCommitmentPoint)
     val remoteHtlcPubkey = Generators.derivePubKey(remoteParams.htlcBasepoint, localPerCommitmentPoint)
     val localRevocationPubkey = Generators.revocationPubKey(remoteParams.revocationBasepoint, localPerCommitmentPoint)
-    val (commitTx, htlcOutputInfo) = Transactions.makeCommitTx(commitmentInput, commitTxNumber, keyManager.paymentPoint(channelKeyPath).publicKey, remoteParams.paymentBasepoint, localParams.isFunder, localParams.dustLimit, localRevocationPubkey, remoteParams.toSelfDelay, localDelayedPaymentPubkey, remotePaymentPubkey, localHtlcPubkey, remoteHtlcPubkey, spec)
-    val (htlcTimeoutTxs, htlcSuccessTxs) = Transactions.makeHtlcTxs(commitTx.tx, localParams.dustLimit, localRevocationPubkey, remoteParams.toSelfDelay, localDelayedPaymentPubkey, localHtlcPubkey, remoteHtlcPubkey, htlcOutputInfo, spec)
+    val outputs = makeCommitTxOutputs(localParams.isFunder, localParams.dustLimit, localRevocationPubkey, remoteParams.toSelfDelay, localDelayedPaymentPubkey, remotePaymentPubkey, localHtlcPubkey, remoteHtlcPubkey, spec)
+    val commitTx = Transactions.makeCommitTx(commitmentInput, commitTxNumber, keyManager.paymentPoint(channelKeyPath).publicKey, remoteParams.paymentBasepoint, localParams.isFunder, outputs)
+    val (htlcTimeoutTxs, htlcSuccessTxs) = Transactions.makeHtlcTxs(commitTx.tx, localParams.dustLimit, localRevocationPubkey, remoteParams.toSelfDelay, localDelayedPaymentPubkey, spec.feeratePerKw, outputs)
     (commitTx, htlcTimeoutTxs, htlcSuccessTxs)
   }
 
-  def makeRemoteTxs(keyManager: KeyManager, channelVersion: ChannelVersion, commitTxNumber: Long, localParams: LocalParams, remoteParams: RemoteParams, commitmentInput: InputInfo, remotePerCommitmentPoint: PublicKey, spec: CommitmentSpec): (CommitTx, Seq[HtlcTimeoutTx], Seq[HtlcSuccessTx]) = {
+  def makeRemoteTxs(keyManager: KeyManager,
+                    channelVersion: ChannelVersion,
+                    commitTxNumber: Long, localParams: LocalParams,
+                    remoteParams: RemoteParams, commitmentInput: InputInfo,
+                    remotePerCommitmentPoint: PublicKey,
+                    spec: CommitmentSpec): (CommitTx, Seq[HtlcTimeoutTx], Seq[HtlcSuccessTx]) = {
     val channelKeyPath = keyManager.channelKeyPath(localParams, channelVersion)
     val localPaymentPubkey = Generators.derivePubKey(keyManager.paymentPoint(channelKeyPath).publicKey, remotePerCommitmentPoint)
     val localHtlcPubkey = Generators.derivePubKey(keyManager.htlcPoint(channelKeyPath).publicKey, remotePerCommitmentPoint)
     val remoteDelayedPaymentPubkey = Generators.derivePubKey(remoteParams.delayedPaymentBasepoint, remotePerCommitmentPoint)
     val remoteHtlcPubkey = Generators.derivePubKey(remoteParams.htlcBasepoint, remotePerCommitmentPoint)
     val remoteRevocationPubkey = Generators.revocationPubKey(keyManager.revocationPoint(channelKeyPath).publicKey, remotePerCommitmentPoint)
-    val (commitTx, htlcOutputInfo) = Transactions.makeCommitTx(commitmentInput, commitTxNumber, remoteParams.paymentBasepoint, keyManager.paymentPoint(channelKeyPath).publicKey, !localParams.isFunder, remoteParams.dustLimit, remoteRevocationPubkey, localParams.toSelfDelay, remoteDelayedPaymentPubkey, localPaymentPubkey, remoteHtlcPubkey, localHtlcPubkey, spec)
-    val (htlcTimeoutTxs, htlcSuccessTxs) = Transactions.makeHtlcTxs(commitTx.tx, remoteParams.dustLimit, remoteRevocationPubkey, localParams.toSelfDelay, remoteDelayedPaymentPubkey, remoteHtlcPubkey, localHtlcPubkey, htlcOutputInfo, spec)
+    val outputs = makeCommitTxOutputs(!localParams.isFunder, remoteParams.dustLimit, remoteRevocationPubkey, localParams.toSelfDelay, remoteDelayedPaymentPubkey, localPaymentPubkey, remoteHtlcPubkey, localHtlcPubkey, spec)
+    val commitTx = Transactions.makeCommitTx(commitmentInput, commitTxNumber, remoteParams.paymentBasepoint, keyManager.paymentPoint(channelKeyPath).publicKey, !localParams.isFunder, outputs)
+    val (htlcTimeoutTxs, htlcSuccessTxs) = Transactions.makeHtlcTxs(commitTx.tx, remoteParams.dustLimit, remoteRevocationPubkey, localParams.toSelfDelay, remoteDelayedPaymentPubkey, spec.feeratePerKw, outputs)
     (commitTx, htlcTimeoutTxs, htlcSuccessTxs)
   }
 

diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/transactions/CommitmentSpec.scala b/eclair-core/src/main/scala/fr/acinq/eclair/transactions/CommitmentSpec.scala
@@ -29,7 +29,10 @@ case object IN extends Direction { def opposite = OUT }
 case object OUT extends Direction { def opposite = IN }
 // @formatter:on
 
-case class DirectedHtlc(direction: Direction, add: UpdateAddHtlc)
+sealed trait CommitmentSpecLink
+case object ToLocalLink extends CommitmentSpecLink
+case object ToRemoteLink extends CommitmentSpecLink
+case class DirectedHtlc(direction: Direction, add: UpdateAddHtlc) extends CommitmentSpecLink
 
 final case class CommitmentSpec(htlcs: Set[DirectedHtlc], feeratePerKw: Long, toLocal: MilliSatoshi, toRemote: MilliSatoshi) {
   val totalFunds = toLocal + toRemote + htlcs.toSeq.map(_.add.amountMsat).sum