Question

I’m trying to implement the new hybi-10 protocol in a python server and for now I succeeded in the handshake and receiving data from the client (JavaScript) but now I’m having problems with sending the data to the client.

I’m using a bit of a code from websockify (encode_hybi function) to encode the frames according to this protocol. But unfortunately the client doesn’t seem to receive the data, as the on message event never fires.

So the code I have is this:

def encode_hybi(self, buf, opcode = 0x01):

    buf = b64encode(buf)

    b1 = 0x80 | (opcode & 0x0f) 
    payload_len = len(buf)
    if payload_len <= 125:
        header = struct.pack('>BB', b1, payload_len)
    elif payload_len > 125 and payload_len < 65536:
        header = struct.pack('>BBH', b1, 126, payload_len)
    elif payload_len >= 65536:
        header = struct.pack('>BBQ', b1, 127, payload_len)

    print repr(header + buf)

    return header + buf

def send(self, data):
    logging.info("Message Sent: %s" % data)

    if (self.protocol == 'hixie-76'):
        self.client.send("\x00%s\xff" % data)
    elif (self.protocol =='hybi-10'):
        msg = self.encode_hybi(data)
        self.client.send(msg)

I’m sending a simple 'OK' through the socket. So after the encode_hybi function I get:
'\x81\x04T0s=' which is sent to JavaScript. I have no response from it, nor errors.

I tried to send other data, for example 'OKKK'. After the encode_hybi function I get: '\x81\x08T0tLSw=='. Don’t know if it helps, but with this data sent, the JavaScript presents an error:

Unrecognized frame opcode: 13.

This error appears every time the length of the data sent is bigger than 3 characters.

I really can’t understand the problem. Is something wrong in the encoding?

Answer 1

You used \n\r\n\r\n at the end of the handshake format, but it should be \r\n\r\n. Currently the \n is part of the key.

Although I don’t understand how you were still able to open a connection, it looks like removing the first \n solves the problem.