encodeMessagePacket: expose haskey

encodeMessagePacket checks for session and behaves differently
based on that. Exposing this difference in behavior.

Signed-off-by: Csaba Kiraly <csaba.kiraly@gmail.com>

libp2pdht/private/eth/p2p/discoveryv5/encoding.nim

@@ -211,8 +211,9 @@ proc encodeStaticHeader*(flag: Flag, nonce: AESGCMNonce, authSize: int):
 
 proc encodeMessagePacket*(rng: var HmacDrbgContext, c: var Codec,
     toId: NodeId, toAddr: Address, message: openArray[byte]):
-    (seq[byte], AESGCMNonce) =
+    (seq[byte], AESGCMNonce, bool) =
   var nonce: AESGCMNonce
+  var haskey: bool
   hmacDrbgGenerate(rng, nonce) # Random AESGCM nonce
   var iv: array[ivSize, byte]
   hmacDrbgGenerate(rng, iv) # Random IV
@@ -230,6 +231,7 @@ proc encodeMessagePacket*(rng: var HmacDrbgContext, c: var Codec,
   var messageEncrypted: seq[byte]
   var initiatorKey, recipientKey: AesKey
   if c.sessions.load(toId, toAddr, recipientKey, initiatorKey):
+    haskey = true
     messageEncrypted = encryptGCM(initiatorKey, nonce, message, @iv & header)
     discovery_session_lru_cache_hits.inc()
   else:
@@ -240,6 +242,7 @@ proc encodeMessagePacket*(rng: var HmacDrbgContext, c: var Codec,
     # message. 16 bytes for the gcm tag and 4 bytes for ping with requestId of
     # 1 byte (e.g "01c20101"). Could increase to 27 for 8 bytes requestId in
     # case this must not look like a random packet.
+    haskey = false
     var randomData: array[gcmTagSize + 4, byte]
     hmacDrbgGenerate(rng, randomData)
     messageEncrypted.add(randomData)
@@ -252,7 +255,7 @@ proc encodeMessagePacket*(rng: var HmacDrbgContext, c: var Codec,
   packet.add(maskedHeader)
   packet.add(messageEncrypted)
 
-  return (packet, nonce)
+  return (packet, nonce, haskey)
 
 proc encodeWhoareyouPacket*(rng: var HmacDrbgContext, c: var Codec,
     toId: NodeId, toAddr: Address, requestNonce: AESGCMNonce, recordSeq: uint64,

libp2pdht/private/eth/p2p/discoveryv5/transport.nim

@@ -56,7 +56,7 @@ proc send(t: Transport, n: Node, data: seq[byte]) =
   t.sendToA(n.address.get(), data)
 
 proc sendMessage*(t: Transport, toId: NodeId, toAddr: Address, message: seq[byte]) =
-  let (data, _) = encodeMessagePacket(t.rng[], t.codec, toId, toAddr,
+  let (data, _, _) = encodeMessagePacket(t.rng[], t.codec, toId, toAddr,
     message)
   t.sendToA(toAddr, data)
 
@@ -74,7 +74,7 @@ proc registerRequest(t: Transport, n: Node, message: seq[byte],
 proc sendMessage*(t: Transport, toNode: Node, message: seq[byte]) =
   doAssert(toNode.address.isSome())
   let address = toNode.address.get()
-  let (data, nonce) = encodeMessagePacket(t.rng[], t.codec,
+  let (data, nonce, haskey) = encodeMessagePacket(t.rng[], t.codec,
     toNode.id, address, message)
 
   t.registerRequest(toNode, message, nonce)

tests/discv5/test_discoveryv5.nim

@@ -629,7 +629,7 @@ suite "Discovery v5 Tests":
         sendNode = newNode(enrRec).expect("Properly initialized record")
       var codec = Codec(localNode: sendNode, privKey: privKey, sessions: Sessions.init(5))
 
-      let (packet, _) = encodeMessagePacket(rng[], codec,
+      let (packet, _, _) = encodeMessagePacket(rng[], codec,
         receiveNode.localNode.id, receiveNode.localNode.address.get(), @[])
       receiveNode.transport.receive(a, packet)
 
@@ -659,7 +659,7 @@ suite "Discovery v5 Tests":
     var codec = Codec(localNode: sendNode, privKey: privKey, sessions: Sessions.init(5))
     for i in 0 ..< 5:
       let a = localAddress(20303 + i)
-      let (packet, _) = encodeMessagePacket(rng[], codec,
+      let (packet, _, _) = encodeMessagePacket(rng[], codec,
         receiveNode.localNode.id, receiveNode.localNode.address.get(), @[])
       receiveNode.transport.receive(a, packet)
 
@@ -691,7 +691,7 @@ suite "Discovery v5 Tests":
 
     var firstRequestNonce: AESGCMNonce
     for i in 0 ..< 5:
-      let (packet, requestNonce) = encodeMessagePacket(rng[], codec,
+      let (packet, requestNonce, _) = encodeMessagePacket(rng[], codec,
         receiveNode.localNode.id, receiveNode.localNode.address.get(), @[])
       receiveNode.transport.receive(a, packet)
       if i == 0:

tests/discv5/test_discoveryv5_encoding.nim

@@ -526,7 +526,7 @@ suite "Discovery v5.1 Additional Encode/Decode":
       reqId = RequestId.init(rng[])
       message = encodeMessage(m, reqId)
 
-    let (data, nonce) = encodeMessagePacket(rng[], codecA, nodeB.id,
+    let (data, nonce, _) = encodeMessagePacket(rng[], codecA, nodeB.id,
       nodeB.address.get(), message)
 
     let decoded = codecB.decodePacket(nodeA.address.get(), data)
@@ -642,7 +642,7 @@ suite "Discovery v5.1 Additional Encode/Decode":
     codecB.sessions.store(nodeA.id, nodeA.address.get(), secrets.initiatorKey,
       secrets.recipientKey)
 
-    let (data, nonce) = encodeMessagePacket(rng[], codecA, nodeB.id,
+    let (data, nonce, _) = encodeMessagePacket(rng[], codecA, nodeB.id,
       nodeB.address.get(), message)
 
     let decoded = codecB.decodePacket(nodeA.address.get(), data)