TypeError: can't concat int to bytes

[jdavid]

I got this error:

  File "/usr/local/lib/python3.9/dist-packages/websockify/websocket.py", line 560, in close
    self.shutdown(socket.SHUT_RDWR, code, reason)
  File "/usr/local/lib/python3.9/dist-packages/websockify/websocket.py", line 547, in shutdown
    self._sendmsg(0x8, msg)
  File "/usr/local/lib/python3.9/dist-packages/websockify/websocket.py", line 734, in _sendmsg
    mask += random.randrange(256)
TypeError: can't concat int to bytes

https://github.com/novnc/websockify/blob/master/websockify/websocket.py#L732-L734

            mask = b''
            for i in range(4):
                mask += random.randrange(256)

Here it tries to concatenate an integer to a byte string, what raises a type error.

[CendioOssman]

Thanks for your report. I'm afraid the client code is rarely used, so it is likely to have more bugs.

Does this fix work:

diff --git a/websockify/websocket.py b/websockify/websocket.py
index dae93b4..af87d3e 100644
--- a/websockify/websocket.py
+++ b/websockify/websocket.py
@@ -731,7 +731,7 @@ class WebSocket(object):
         if self.client:
             mask = b''
             for i in range(4):
-                mask += random.randrange(256)
+                mask += random.randrange(256).to_bytes()
             frame = self._encode_hybi(opcode, msg, mask)
         else:
             frame = self._encode_hybi(opcode, msg)

[jdavid]

It should do, but we've moved to websocket-client

[CendioOssman]

Okay. I've pushed the above fix as a2362da. Hopefully it is sufficient to fix the client side.