Client running into ERR_SSL_PROTOCOL_ERROR

[y3pio]

Running into similar issue as #729 -- Tried the solution(?) posted on there to use file input stream:

File initialFile = new File("keystore.pfx");
InputStream is = new FileInputStream(initialFile);

Still no luck. Posted detailed description on Stackoverflow: https://stackoverflow.com/questions/79343476/need-help-setting-up-netty-socketio-ssl-on-spring-boot-application

My code below:

application.properties -

spring.application.name=feed-service

# SocketIO/Netty Config
socket.port=8081
socket.ssl.enabled=true
socket.ssl.key-store=/etc/letsencrypt/live/<my_server>/keystore.jks
socket.ssl.key-store-password=<redacted_password>

# SSL Config
server.port=8443
security.require-ssl=true
server.ssl.key-store=/etc/letsencrypt/live/<my_server>/keystore.p12
server.ssl.key-store-password=<redacted_password>
server.ssl.keyStoreType=PKCS12
server.ssl.keyAlias=tomcat

SocketIO config class on backend:

@Component
@RequiredArgsConstructor
@Slf4j
public class SocketIOConfig {

  @Value("${socket.port}")
  private int socketPort;

  @Value("${socket.ssl.enabled}")
  private Boolean isSslEnabled;

  @Value("${socket.ssl.key-store}")
  private String keyStore;

  @Value("${socket.ssl.key-store-password}")
  private String keyStorePassword;

  // SocketIOServer class is used to create a socket server
  private SocketIOServer server;

  @Bean
  public SocketIOServer socketIOServer() {
    // Configuration object holds the server settings
    Configuration config = new Configuration();

    config.setPort(socketPort);
    config.setEnableCors(true);

    if (isSslEnabled) {
      //SSL
      log.info("[IO] SSL Enabled for SocketIO.");
      config.setKeyStorePassword(keyStorePassword);
      InputStream stream = getClass().getClassLoader().getResourceAsStream(keyStore);
      config.setKeyStore(stream);
    }

    server = new SocketIOServer(config);
    server.start();

    server.addConnectListener(client -> log.info("\n[IO] Client connected: {}\n", client.getSessionId()));
    server.addDisconnectListener(client -> log.info("\n[IO] Client disconnected: {}\n", client.getSessionId()));

    return server;
  }

  @PreDestroy
  public void stopSocketServer() {
    this.server.stop();
  }
}

ReactJS frontend client:

import React, { useState, useContext, useEffect } from "react";
import io from 'socket.io-client';
import { EventType, FeedableEventTypes } from '../types/EventType';

const socket = io('https://<my_server>:8081'); // TODO: Figure out how to set SSL on server.

const SocketIOContext = React.createContext();

export const SocketIOProvider = ({ children }) => {
  const [connectedFeeds, setConnectedFeeds] = useState(FeedableEventTypes);
  const [isInitialized, setIsInitialized] = useState(false);
  const defaultContext = {
    socket,
    connectedFeeds,
    setConnectedFeeds,
    isInitialized,
    setIsInitialized
  }

...rest of the code