Add tests from spec

eclair-core/src/main/scala/fr/acinq/eclair/wire/protocol/Onion.scala

@@ -470,7 +470,7 @@ object OnionCodecs {
 
   private val blindingKey: Codec[Blinding] = variableSizeBytesLong(varintoverflow, "blinding" | publicKey).as[Blinding]
 
-  val messageRelayNextCodec: Codec[MessageRelayNext] = TlvCodecs.lengthPrefixedTlvStream[OnionTlv](
+  val messageRelayNextCodec: Codec[MessageRelayNext] = TlvCodecs.tlvStream[OnionTlv](
     discriminated[OnionTlv].by(varint)
       .typecase(UInt64(4), outgoingNodeId)
       .typecase(UInt64(12), blindingKey)).complete

eclair-core/src/test/scala/fr/acinq/eclair/wire/protocol/OnionMessagesSpec.scala

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2021 ACINQ SAS
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package fr.acinq.eclair.wire.protocol
+
+import fr.acinq.bitcoin.Crypto.{PrivateKey, PublicKey}
+import fr.acinq.bitcoin.{ByteVector32, Crypto}
+import fr.acinq.eclair.crypto.Sphinx
+import org.scalatest.funsuite.AnyFunSuite
+import scodec.bits.{ByteVector, HexStringSyntax}
+import scodec.{Attempt, DecodeResult}
+
+import scala.util.{Failure, Success}
+
+/**
+ * Created by thomash on 23/09/2021.
+ */
+
+class OnionMessagesSpec extends AnyFunSuite {
+
+  test("Simple enctlv for Alice, next is Bob") {
+    val nodePrivateKey = PrivateKey(hex"414141414141414141414141414141414141414141414141414141414141414101")
+    val nodeId = PublicKey(hex"02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619")
+    assert(nodePrivateKey.publicKey == nodeId)
+    val blindingSecret = PrivateKey(hex"050505050505050505050505050505050505050505050505050505050505050501")
+    val blindingKey = PublicKey(hex"0362c0a046dacce86ddd0343c6d3c7c79c2208ba0d9c9cf24a6d046d21d21f90f7")
+    assert(blindingSecret.publicKey == blindingKey)
+    val sharedSecret = ByteVector32(hex"2e83e9bc7821d3f6cec7301fa8493aee407557624fb5745bede9084852430e3f")
+    assert(Sphinx.computeSharedSecret(nodeId, blindingSecret) == sharedSecret)
+    assert(Sphinx.computeSharedSecret(blindingKey, nodePrivateKey) == sharedSecret)
+    assert(Sphinx.mac(ByteVector("blinded_node_id".getBytes), sharedSecret) == ByteVector32(hex"7d846b3445621d49a665e5698c52141e9dda8fa2fe0c3da7e0f9008ccc588a38"))
+    val blindedNodeId = PublicKey(hex"02004b5662061e9db495a6ad112b6c4eba228a079e8e304d9df50d61043acbc014")
+    val nextNodeId = PublicKey(hex"0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c")
+    val encmsg = hex"04210324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c"
+    val Sphinx.RouteBlinding.BlindedRoute(_, blindedHops) = Sphinx.RouteBlinding.create(blindingSecret, nodeId :: Nil, encmsg :: Nil)
+    assert(blindedHops.head.blindedPublicKey == blindedNodeId)
+    assert(Crypto.sha256(blindingKey.value ++ sharedSecret.bytes) == ByteVector32(hex"bae3d9ea2b06efd1b7b9b49b6cdcaad0e789474a6939ffa54ff5ec9224d5b76c"))
+    val enctlv = hex"6970e870b473ddbc27e3098bfa45bb1aa54f1f637f803d957e6271d8ffeba89da2665d62123763d9b634e30714144a1c165ac9"
+    assert(blindedHops.head.encryptedPayload == enctlv)
+    OnionCodecs.messageRelayNextCodec.decode(encmsg.bits) match {
+      case Attempt.Successful(DecodeResult(relayNext, _)) => assert(relayNext.nextNodeId == nextNodeId)
+      case Attempt.Failure(err) => fail(err.toString)
+    }
+    Sphinx.RouteBlinding.decryptPayload(nodePrivateKey, blindingKey, enctlv) match {
+      case Success((decrypted, nextBlindingKey)) => assert(decrypted == encmsg)
+      case Failure(err) => fail(err.toString)
+    }
+  }
+
+}