尝试将 swift 客户端连接到 socket.io 服务器时收到 SSL 错误

Question

I am setting up a Socket.io server in Node.js and client in Swift to implement a real-time chat app.

On the server side, here is the code:

const express = require('express');
const app = express();
const port = process.env.PORT || 8080;
const server = app.listen(port, () => {
    console.log(`A Node Js API is listening on port: ${port}`);
});
const io = require("socket.io")(server, {
    rejectUnauthorized: false
});

//set socket.io listeners
io.on('connection', (socket) => {
  console.log('a user connected');

  socket.on('disconnect', () => {
    console.log('user disconnected');
  });

  socket.on("connect_error", (err) => {
    console.log(`connect_error due to ${err.message}`);
    });
});

On the client side, here is the code:

import SocketIO

class SocketIOManager: NSObject {
    static let sharedInstance = SocketIOManager()
    static let manager = SocketManager(socketURL: URL(string: "https://localhost:8080")!, config: [.log(true), .compress])
    let socket = manager.defaultSocket


    func establishConnection() {
        socket.on("test") { dataArray, ack in
            print(dataArray)
        }
        socket.connect()
    }

    func closeConnection() {
        socket.disconnect()
    }
}

I call establishConnection() in AppDelegate in the applicationDidBecomeActive() method. When establishConnection() is getting called, I receive the following SSL Error:

LOG SocketManager: Trying to reconnect
LOG SocketIOClient{/}: Handling event: reconnectAttempt with data: [-2]
LOG SocketManager: Scheduling reconnect in 25.7991450561197s
LOG SocketEngine: Starting engine. Server: https://localhost:8080
LOG SocketEngine: Handshaking
LOG SocketEnginePolling: Doing polling GET https://localhost:8080/socket.io/?transport=polling&b64=1 
...
finished with error [-1200] Error Domain=NSURLErrorDomain Code=-1200 "An SSL error has occurred and a secure connection to the server cannot be made." 
UserInfo={NSErrorFailingURLStringKey=https://localhost:8080/socket.io/?transport=polling&b64=1, NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFStreamErrorDomainKey=3, 
_NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <A81C6803-9CF8-4930-A6C8-0C633C165D25>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey

I've tried editing Info.plist to change the App Transport Security Settings, but I'm still receiving the error. What could be going wrong?

Answer 1

For anyone struggle that issue, here's a working solution. you should use the .secure(true), .selfSigned(true) options and the URLAuthenticationChallenge .

class ServerLiveDataSocket : NSObject
{
    
    static let shared = ServerLiveDataSocket()
    
    var manager : SocketManager!
    var socket : SocketIOClient!
    
    func initSocketService(symbols : [String], dataPovider : DataProvider)
    {
        manager = SocketManager(socketURL: URL(string: "YOUR_HTTPS_URL_ADDRESS")!, config: [.log(true),
        .compress, .secure(true), .selfSigned(true), .sessionDelegate(self)])
        socket = manager.defaultSocket
        socket.on("users", callback: { data,ack in
            print(data)
        })
        socket.on(clientEvent: .connect) { data, ack in
            self.socket.emit("userNew", userData)
        }
        socket.connect()
    }
    
    
}
extension ServerLiveDataSocket : URLSessionDelegate
{
    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        completionHandler(.useCredential, URLCredential(trust: challenge.protectionSpace.serverTrust!))
    }
}