websocket与RPC

1、websocket

• new WebSocket() 是固定的语法，可以作为定位的关键词
• 常见用法
  • ws.send 用于向服务器发送数据
  • ws.onopen 用于指定连接成功后的回调函数
  • ws.onmessage 用于指定收到服务器数据后的回调函数
• 定位
  • 定位send
    • 可以先搜索new WebSocket()，找到相应代码位置，打上断点
    • 刷新页面，然后对该对象的send方法进行hook，并在hook代码中加入debugger，进行定位
    • 定位好以后，对于hook的send方法重新赋回原函数
  • 定位onmessage
    • 搜索onmessage 或者 addEventListener("message")

      ws.onmessage = function(event) {
        var data = event.data;
      };
       
      ws.addEventListener("message", function(event) {
        var data = event.data;
      });

2、RPC

• 服务端通用模板

  import asyncio
  import websockets
  
  async def main_logic(websocket, path):
      if path == '/douyin':
          data = [i for i in range(1,100)] # 模拟待处理数据，可以通过方法去实时获取
          for i in data:
              await websocket.send(str(i))
              recv_text = await websocket.recv()
              # 业务处理逻辑相关代码，对响应数据进行处理
              print(recv_text)
  
  start_server = websockets.serve(main_logic, '127.0.0.1', 9999)
  asyncio.get_event_loop().run_until_complete(start_server)
  asyncio.get_event_loop().run_forever()

  如果建立多个连接，会异步处理main_logic中的任务

• 某音直播数据RPC示例

  • 客户端client.js
    

    !function () {
        var res = s.toObject();
        if (window.flag_) {
            window.ws_.send(JSON.stringify(res));
        } else {
            var ws = new WebSocket("ws://127.0.0.1:9999");
            window.ws_ = ws;
            window.flag_ = true;
            ws.open = function (evt) {
            };
            ws.onmessage = function (evt) {
                ws.send(JSON.stringify(res));
            }
        }
    }();

  • 服务端server.py

    import asyncio
    import websockets
    
    async def check_permit(websocket):
        # 在这里可以编写相关业务代码逻辑，用于向客户端发送数据
        send_text = 'xxx'
        await websocket.send(send_text)
        return True
    
    async def recv_msg(websocket):
        while 1:
            recv_text = await websocket.recv()
            # 业务处理逻辑相关代码，对响应数据进行处理
            print(recv_text)
    
    
    async def main_logic(websocket, path):
        await check_permit(websocket)
        await recv_msg(websocket)
    
    start_server = websockets.serve(main_logic, '127.0.0.1', 9999)
    asyncio.get_event_loop().run_until_complete(start_server)
    asyncio.get_event_loop().run_forever()

• 某博登录参数RPC

  • client.js

    // 该代码放到makeRequest函数内部
    !function () {
        if (window.flag_) {
        } else {
            window.weibo_ = makeRequest;
            var ws = new WebSocket("ws://127.0.0.1:9999");
            window.flag_ = true;
            ws.onopen = function (evt) {
            };
            ws.onmessage = function (evt) {
                var data_ = evt.data;
                var result = data_.split(",");
                var res = window.weibo_(result[0], result[1], 7, false);
                ws.send(JSON.stringify(res));
            }
        }
    }();

  • server.py

    import asyncio
    import websockets
    
    async def check_permit(websocket):
        # 账号列表
        for send_text in [
            '11111111111,111',
            '11111111112,112',
            '11111111113,113',
            '11111111114,114'
        ]:
            await websocket.send(send_text)
        return True
    
    async def recv_msg(websocket):
        while 1:
            recv_text = await websocket.recv()
            # 拿到相关加密参数
            print(recv_text)
    
    async def main_logic(websocket, path):
        await check_permit(websocket)
        await recv_msg(websocket)
    
    start_server = websockets.serve(main_logic, '127.0.0.1', 9999)
    asyncio.get_event_loop().run_until_complete(start_server)
    asyncio.get_event_loop().run_forever()