Fiddler 웹소켓 데이터 캡쳐

* fiddler script1
Handler 클래스 내에 아래 함수를 정의하면 웹 소켓 데이터 확인이 가능하다.

 static function OnWebSocketMessage(oMsg: WebSocketMessage) 
 {
         FiddlerApplication.Log.LogString(oMsg.ToString());
 }

* fiddler script2
Fiddler 로그 탭의 WebSocket 트래픽 프레임은 그룹화되지 않으므로 프레임 간에 탐색이 어렵고
연속 프레임은 디코딩되지 않아 바이너리로 표시되며 트래픽이 많은 경우 Fiddler가 중지될 수 있다.
Main 함수 및 Handler 클래스 내에 아래 스크립트를 추가하여 위 문제를 해결한다.

    static function Main() 
     {
         // ...
      
         //
         // Print Web Socket frame every 2 seconds
         //
         printSocketTimer =
             new System.Threading.Timer(PrintSocketMessage, null, 0, 2000);
     }
 
 static var socketMessages = new System.Collections.Queue();
 	static var printSocketTimer = null;
 	static var requestBodyBuilder = new System.Text.StringBuilder();
 	static var requestUrlBuilder = new System.Text.StringBuilder();
 	static var requestPayloadIsJson = false;
 	static var requestPartCount = 0;
        
 	//
 	// Listen to WebSocketMessage event, and add the socket messages
 	// to the static queue.
 	//
 	static function OnWebSocketMessage(oMsg: WebSocketMessage)
 	{       
 		// Monitor.Enter(socketMessages);
 		socketMessages.Enqueue(oMsg);
 		// Monitor.Exit(socketMessages);          
 	}
 	
 		
 	//
 	// Take socket messages from the static queue, and generate fake
 	// HTTP requests that will be caught by Fiddler. 
 	//
 	static function PrintSocketMessage(stateInfo: Object)
 	{
 		// Monitor.Enter(socketMessages);        
        
 		while (socketMessages.Count > 0)
 		{
 			var oMsg = socketMessages.Dequeue();
 
 			ExtractSocketMessage(oMsg);          
 		}
        
 		// Monitor.Exit(socketMessages);       
 	}
 		
 	//
 	// Build web socket message information in JSON format, and send this JSON
 	// information in a fake HTTP request that will be caught by Fiddler
 	//
 	// If a frame is split in multiple messages, following function will combine
 	// them into one 
 	//
 	static function ExtractSocketMessage(oMsg: WebSocketMessage)
 	{      
 		if (oMsg.FrameType != WebSocketFrameTypes.Continuation)
 		{               
 			var messageID = String.Format(
 				"{0}.{1}", oMsg.IsOutbound ? "Client" : "Server", oMsg.ID);
            
 			var wsSession = GetWsSession(oMsg);
 			requestUrlBuilder.AppendFormat("{0}.{1}", wsSession, messageID);
                
 			requestBodyBuilder.Append("{");
 			requestBodyBuilder.AppendFormat("\"doneTime\": \"{0}\",", 
 				oMsg.Timers.dtDoneRead.ToString("hh:mm:ss.fff"));
 			requestBodyBuilder.AppendFormat("\"messageType\": \"{0}\",", 
 				oMsg.FrameType);
 			requestBodyBuilder.AppendFormat("\"messageID\": \"{0}\",", messageID);
 			requestBodyBuilder.AppendFormat("\"wsSession\": \"{0}\",", wsSession);
 			requestBodyBuilder.Append("\"payload\": ");
                
                 
 			var payloadString = oMsg.PayloadAsString();
 
             
 			if (oMsg.FrameType == WebSocketFrameTypes.Binary)
 			{
 				payloadString = HexToString(payloadString); 
 			}
 
 			if (payloadString.StartsWith("{"))
 			{
 				requestPayloadIsJson = true;                   
 			}
 			else
 			{
 				requestBodyBuilder.Append("\"");
 			}
                
 			requestBodyBuilder.AppendFormat("{0}", payloadString);
                           
 		}
 		else
 		{
 			var payloadString = HexToString(oMsg.PayloadAsString());
 			requestBodyBuilder.AppendFormat("{0}", payloadString);
 		}
            
 		requestPartCount++;
            
 		if (oMsg.IsFinalFrame)
 		{
 			if (!requestPayloadIsJson)
 			{
 				requestBodyBuilder.Append("\"");
 			}
            
 			requestBodyBuilder.AppendFormat(", \"requestPartCount\": \"{0}\"", 
 				requestPartCount);
                
 			requestBodyBuilder.Append("}");      
             
                                 
             
 			SendRequest(requestUrlBuilder.ToString(), requestBodyBuilder.ToString()); 
                         
 			requestBodyBuilder.Clear();
 			requestUrlBuilder.Clear();
 			requestPayloadIsJson = false;
 			requestPartCount = 0;
 		}       
 	}
 	
 	//
 	// Generate fake HTTP request with JSON data that will be caught by Fiddler
 	// We can inspect this request in "Inspectors" tab -> "JSON" sub-tab
 	//
 	static function SendRequest(urlPath: String, message: String)
 	{       
 		var request = String.Format(
 			"POST http://fakewebsocket/{0} HTTP/1.1\n" +
 			"User-Agent: Fiddler\n" +
 			"Content-Type: application/json; charset=utf-8\n" +
 			"Host: fakewebsocket\n" +
 			"Content-Length: {1}\n\n{2}",
 			urlPath, message.Length, message);
            
 		FiddlerApplication.oProxy.SendRequest(request, null);
 	}
 	
 	//
 	// Unfortunately, WebSocketMessage class does not have a member for 
 	// Web Socket session number. Therefore, we are extracting session number
 	// from its string output.
 	//
 	static function GetWsSession(oMsg: WebSocketMessage)
 	{
 		var message = oMsg.ToString();
 		var index = message.IndexOf(".");
 		var wsSession = message.Substring(0, index);
        
 		return wsSession;
 	}
        
 	//
 	// Extract Hex to String.
 	// E.g., 7B-22-48-22-3A-22-54-72-61-6E to {"H":"TransportHub","M":"
 	//
 	static function HexToString(sourceHex: String)
 	{
 		sourceHex = sourceHex.Replace("-", "");
        
 		var sb = new System.Text.StringBuilder();
        
 		for (var i = 0; i < sourceHex.Length; i += 2)
 		{
 			var hs = sourceHex.Substring(i, 2);
 			sb.Append(Convert.ToChar(Convert.ToUInt32(hs, 16)));
 		}
        
 		var ascii = sb.ToString();
 		return ascii;
 
 	}

 

출처: https://www.codeproject.com/Articles/718660/Debug-Inspect-WebSocket-traffic-with-Fiddler