Use new derivation scheme for fundee scenario

ACINQ · Jun 5, 2019 · 3b25ea5 · 3b25ea5
1 parent 2a329d6
commit 3b25ea5
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Showing 2 changed files with 26 additions and 12 deletions.
diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala b/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala
@@ -92,19 +92,37 @@ object Channel {
   case class RemoteError(e: Error) extends ChannelError
   // @formatter:on
 
-  def makeChannelKeyPathFromInput(fundingInput: TxIn): KeyPath = {
+  def fourByteGroupsFromSha(input: ByteVector): List[Long] = {
     // split the SHA into 8 groups of 4 bytes and convert to uint32
-    val List(h0, h1, h2, h3, h4, h5, h6, h7) = Crypto.sha256(fundingInput.outPoint.hash).toArray.grouped(4).map(ByteVector(_).toLong(signed = false)).toList
-    KeyPath(Seq(47, 2, h0, h1, h2, h3, h4, h5, h6, h7, 0))
+    Crypto.sha256(input).toArray.grouped(4).map(ByteVector(_).toLong(signed = false)).toList
   }
 
   def makeFunderChannelParams(nodeParams: NodeParams, defaultFinalScriptPubKey: ByteVector, isFunder: Boolean, fundingSatoshis: Long, fundingInput: TxIn): LocalParams = {
     require(isFunder, s"Wrong params for isFunder=$isFunder")
 
-    val channelKeyPath = makeChannelKeyPathFromInput(fundingInput)
+    val List(h0, h1, h2, h3, h4, h5, h6, h7) = fourByteGroupsFromSha(fundingInput.outPoint.hash)
+    val channelKeyPath = KeyPath(Seq(47, 2, h0, h1, h2, h3, h4, h5, h6, h7, 0))
+
     makeChannelParams(nodeParams, defaultFinalScriptPubKey, isFunder, fundingSatoshis, Left(channelKeyPath))
   }
 
+  def makeFundeeChannelParams(nodeParams: NodeParams, open: OpenChannel, defaultFinalScriptPubKey: ByteVector, fundingSatoshis: Long): LocalParams = {
+
+    val List(h0, h1, h2, h3, h4, h5, h6, h7) = fourByteGroupsFromSha(ByteVector.view(s"${Globals.blockCount} || 0".getBytes))
+    val publicKeyPath = KeyPath(Seq(47, 2, h0, h1, h2, h3, h4, h5, h6, h7, 2))
+
+    val localFundingPubkey = nodeParams.keyManager.fundingPublicKey(publicKeyPath).publicKey
+    val fundingPubkeyScript = Script.write(Script.pay2wsh(Scripts.multiSig2of2(localFundingPubkey, open.fundingPubkey)))
+
+    val List(s0, s1, s2, s3, s4, s5, s6, s7) = fourByteGroupsFromSha(fundingPubkeyScript)
+    val pointsKeyPath = KeyPath(Seq(47, 2, s0, s1, s2, s3, s4, s5, s6, s7, 1))
+
+    val channelKeyPaths = KeyPathFundee(publicKeyPath, pointsKeyPath)
+
+    makeChannelParams(nodeParams, defaultFinalScriptPubKey, isFunder = false, fundingSatoshis, Right(channelKeyPaths))
+  }
+
+
   def makeChannelParams(nodeParams: NodeParams, defaultFinalScriptPubKey: ByteVector, isFunder: Boolean, fundingSatoshis: Long, channelKeyPath: Either[DeterministicWallet.KeyPath, KeyPathFundee]): LocalParams = {
     LocalParams(
       nodeParams.nodeId,

diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala b/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala
@@ -271,7 +271,10 @@ class Peer(nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: Actor
       d.transport ! TransportHandler.ReadAck(msg)
       d.channels.get(TemporaryChannelId(msg.temporaryChannelId)) match {
         case None =>
-          val (channel, localParams) = createNewChannel(nodeParams, funder = false, fundingSatoshis = msg.fundingSatoshis, origin_opt = None)
+
+          val channel = spawnChannel(nodeParams, origin_opt = None)
+          val defaultFinalScriptPubkey = Helpers.getFinalScriptPubKey(wallet, nodeParams.chainHash)
+          val localParams = Channel.makeFundeeChannelParams(nodeParams, msg, defaultFinalScriptPubkey, msg.fundingSatoshis)
           val temporaryChannelId = msg.temporaryChannelId
           log.info(s"accepting a new channel to $remoteNodeId temporaryChannelId=$temporaryChannelId")
 
@@ -486,13 +489,6 @@ class Peer(nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: Actor
     case DISCONNECTED -> _ if nodeParams.autoReconnect && stateData.address_opt.isDefined => cancelTimer(RECONNECT_TIMER)
   }
 
-  def createNewChannel(nodeParams: NodeParams, funder: Boolean, fundingSatoshis: Long, origin_opt: Option[ActorRef]): (ActorRef, LocalParams) = {
-    val defaultFinalScriptPubKey = Helpers.getFinalScriptPubKey(wallet, nodeParams.chainHash)
-    val localParams = makeChannelParams(nodeParams, defaultFinalScriptPubKey, funder, fundingSatoshis)
-    val channel = spawnChannel(nodeParams, origin_opt)
-    (channel, localParams)
-  }
-
   def spawnChannel(nodeParams: NodeParams, origin_opt: Option[ActorRef]): ActorRef = {
     val channel = context.actorOf(Channel.props(nodeParams, wallet, remoteNodeId, watcher, router, relayer, origin_opt))
     context watch channel