Check for more required fields

src/main/java/org/ethereum/beacon/discovery/pipeline/HandlerUtil.java

@@ -24,7 +24,7 @@ public static boolean requireField(Field<?> field, Envelope envelope) {
     }
   }
 
-  public static boolean requireNodeRecord(Envelope envelope) {
+  public static boolean requireSessionWithNodeRecord(Envelope envelope) {
     if (!requireField(Field.SESSION, envelope)) {
       return false;
     }

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/BadPacketHandler.java

@@ -23,7 +23,7 @@ public void handle(Envelope envelope) {
     LOG.trace(
         () ->
             String.format(
-                "Envelope %s in BadPacketLogger, requirements are satisfied!",
+                "Envelope %s in BadPacketHandler, requirements are satisfied!",
                 envelope.getIdString()));
 
     LOG.debug(

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/HandshakeMessagePacketHandler.java

@@ -58,7 +58,7 @@ public void handle(Envelope envelope) {
     LOG.trace(
         () ->
             String.format(
-                "Envelope %s in AuthHeaderMessagePacketHandler, requirements are satisfied!",
+                "Envelope %s in HandshakeMessagePacketHandler, requirements are satisfied!",
                 envelope.getIdString()));
 
     HandshakeMessagePacket packet = envelope.get(Field.PACKET_HANDSHAKE);

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/MessageHandler.java

@@ -40,7 +40,7 @@ public void handle(Envelope envelope) {
     if (!HandlerUtil.requireField(Field.MESSAGE, envelope)) {
       return;
     }
-    if (!HandlerUtil.requireNodeRecord(envelope)) {
+    if (!HandlerUtil.requireSessionWithNodeRecord(envelope)) {
       return;
     }
     LOG.trace(

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/NextTaskHandler.java

@@ -47,7 +47,7 @@ public static void tryToSendAwaitTaskIfAny(
 
   @Override
   public void handle(Envelope envelope) {
-    if (!HandlerUtil.requireNodeRecord(envelope)) {
+    if (!HandlerUtil.requireSessionWithNodeRecord(envelope)) {
       return;
     }
     LOG.trace(

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/NodeSessionManager.java

@@ -75,7 +75,7 @@ public void handle(final Envelope envelope) {
       return;
     }
     LOG.trace(
-        "Envelope {} in NodeIdToSession, requirements are satisfied!", envelope.getIdString());
+        "Envelope {} in NodeSessionManager, requirements are satisfied!", envelope.getIdString());
 
     SessionLookup sessionRequest = envelope.get(Field.SESSION_LOOKUP);
     envelope.remove(Field.SESSION_LOOKUP);

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/PacketDispatcherHandler.java

@@ -34,7 +34,7 @@ public void handle(Envelope envelope) {
     LOG.trace(
         () ->
             String.format(
-                "Envelope %s in UnknownPacketTypeByStatus, requirements are satisfied!",
+                "Envelope %s in PacketDispatcherHandler, requirements are satisfied!",
                 envelope.getIdString()));
 
     Packet<?> packet = envelope.get(Field.PACKET);

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/UnauthorizedMessagePacketHandler.java

@@ -37,7 +37,7 @@ public void handle(Envelope envelope) {
     LOG.trace(
         () ->
             String.format(
-                "Envelope %s in NotExpectedIncomingPacketHandler, requirements are satisfied!",
+                "Envelope %s in UnauthorizedMessagePacketHandler, requirements are satisfied!",
                 envelope.getIdString()));
 
     NodeSession session = envelope.get(Field.SESSION);

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/WhoAreYouPacketHandler.java

@@ -44,12 +44,15 @@ public WhoAreYouPacketHandler(final Pipeline outgoingPipeline, final Scheduler s
 
   @Override
   public void handle(final Envelope envelope) {
-    if (!HandlerUtil.requireNodeRecord(envelope)) {
+    if (!HandlerUtil.requireSessionWithNodeRecord(envelope)) {
       return;
     }
     if (!HandlerUtil.requireField(Field.PACKET_WHOAREYOU, envelope)) {
       return;
     }
+    if (!HandlerUtil.requireField(Field.MASKING_IV, envelope)) {
+      throw new IllegalStateException("Internal error: No MASKING_IV field for WhoAreYou packet");
+    }
     LOG.trace(
         () ->
             String.format(
@@ -82,9 +85,6 @@ public void handle(final Envelope envelope) {
 
       // The handshake uses the unmasked WHOAREYOU challenge as an input:
       // challenge-data     = masking-iv || static-header || authdata
-      if (!envelope.contains(Field.MASKING_IV)) {
-        throw new IllegalStateException("Internal error: No MASKING_IV field for WhoAreYou packet");
-      }
       Bytes16 whoAreYouMaskingIV = envelope.get(Field.MASKING_IV);
       Bytes challengeData =
           Bytes.wrap(