How to create Python secure websocket client request?

Question

My Python secure websocket client code giving me exception as follows:

[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:748)

I have created my private certificate and and sign certificate as well, but I am not able to connect to it using Python script as follows:

import json
from websocket import create_connection


class subscriber:
   def listenForever(self):
   try:
      # ws = create_connection("wss://localhost:9080/websocket")
      ws = create_connection("wss://nbtstaging.westeurope.cloudapp.azure.com:9090/websocket")
      ws.send("test message")
      while True:
          result = ws.recv()
          result = json.loads(result)
          print("Received '%s'" % result)

      ws.close()
  except Exception as ex:
      print("exception: ", format(ex))


try:
    subscriber().listenForever()
except:
    print("Exception occured: ")

My https/wss server script in python with tornado as follows:

import tornado.web
import tornado.websocket
import tornado.httpserver
import tornado.ioloop
import os
import ssl

ssl_root = os.path.join(os.path.dirname(__file__), 'ssl1_1020')


class WebSocketHandler(tornado.websocket.WebSocketHandler):
    def check_origin(self, origin):
        return True

    def open(self):
        pass

    def on_message(self, message):
        self.write_message("Your message was: " + message)
        print("message received: ", format(message))

    def on_close(self):
        pass


class IndexPageHandler(tornado.web.RequestHandler):
    def get(self):
        self.render("index.html")


class Application(tornado.web.Application):
    def __init__(self):
        handlers = [
           (r'/', IndexPageHandler),
           (r'/websocket', WebSocketHandler),
        ]

        settings = {
            'template_path': 'templates'
        }
        tornado.web.Application.__init__(self, handlers, **settings)


ssl_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
ssl_ctx.load_cert_chain(ssl_root+"/server.crt",
                    ssl_root + "/server.pem")


if __name__ == '__main__':
    ws_app = Application()
    server = tornado.httpserver.HTTPServer(ws_app, ssl_options=ssl_ctx,)
    server.listen(9081, "0.0.0.0")
    print("server started...")
    tornado.ioloop.IOLoop.instance().start()

steps used to create SSL signed certificates:

openssl genrsa -des3 -out server.key 1024
openssl rsa -in server.key -out server.pem
openssl req -new -nodes -key server.pem -out server.csr
openssl x509 -req -days 365 -in server.csr -signkey server.pem -out server.crt

Answer 1

Finally I found a solution, I updated python client script while making connection to secure web socket url to ignore cert request as follows:

 import ssl
 import websocket

 ws = websocket.WebSocket(sslopt={"cert_reqs": ssl.CERT_NONE})
 ws.connect("wss://xxx.com:9090/websocket")

Answer 2

For me, ignoring the errors is not an options, I had to use my self signed certificate because of SSL pinning in a complex IoT environment:

import asyncio
import pathlib
import ssl
import websockets

ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
localhost_pem = pathlib.Path(__file__).with_name("localhost.pem")
ssl_context.load_verify_locations(localhost_pem)

async def hello():
    uri = "wss://localhost:8765"
    async with websockets.connect(
        uri, ssl=ssl_context
    ) as websocket:
        name = input("What's your name? ")

        await websocket.send(name)
        print(f"> {name}")

        greeting = await websocket.recv()
        print(f"< {greeting}")

asyncio.get_event_loop().run_until_complete(hello())

Found it here on the websocket repo's examples folder.

P.S

I changed it from SSLContext(ssl.PROTOCOL_TLS_CLIENT) to SSLContext(ssl.PROTOCOL_TLSv1_2) to make it work

Answer 3

If anyone is curious in the future why wss python server fails is because of this right here in the tornado documentation:

When using a secure websocket connection (wss://) with a self-signed certificate, the connection from a browser may fail because it wants to show the “accept this certificate” dialog but has nowhere to show it. You must first visit a regular HTML page using the same certificate to accept it before the websocket connection will succeed.

Answer 4

Only try the below for testing purposes only. The below is a highly insecure kluge:

import asyncio, ssl, websockets

#todo kluge
#HIGHLY INSECURE
ssl_context = ssl.SSLContext()
ssl_context.check_hostname = False
ssl_context.verify_mode = ssl.CERT_NONE
#HIGHLY INSECURE
#todo kluge

uri = "wss://myAwesomeSSL.wss.kluge"

async with websockets.connect(uri, ssl=ssl_context) as websocket:
        greeting = await websocket.recv()
        print(f"< {greeting}")