string ~ ubyte

[div0]

On 31/10/2010 11:36, Bob Cowdery wrote:
> Hi
> I'm implementing a web sockets server as part of the UI for my
> application. It's almost working but the connection closes on me just
> after the handshake. I'm pretty sure the handshake response I'm sending
> is incorrect.
>
> This is the last bit of the code (I've missed ot the bit that creates
> the parts as I think that is ok):
>
>          // Create the challenge response
>          // The response is formed by a concatenation of
>          // part_1 + part_2 + key (where parts are 32 bit integers and
> key is 8 bytes)
>          // The parts must be in big endian order and the whole forms a
> 128 bit value
>          // The response is then the MD5 hash of this value
>          writeln("Creating response");
>          auto response = new ubyte[16];
>          response[0] = part_1&  0xFF;
>          response[1] = (part_1>>  8)&  0xFF;
>          response[2] = (part_1>>  16)&  0xFF;
>          response[3] = (part_1>>  24)&  0xFF;
>          response[4] = part_2&  0xFF;
>          response[5] = (part_2>>  8)&  0xFF;
>          response[6] = (part_2>>  16)&  0xFF;
>          response[7] = (part_2>>  24)&  0xFF;
>          foreach(i, value; key) {
>              response[i+8] = value;
>          }
>
>          // Create an MD5 hash of the result.
>          ubyte digest[16];
>          sum(digest, response);
>
>          // Send the handshake
>          writeln("Handshake sending: ", handshake ~ digestToString(digest));
>          this.sock.send(handshake ~ digestToString(digest));
>
> The result of running gives me a handshake respose of:
>
>          Creating response
>          Handshake sending: HTTP/1.1 101 Web Socket Protocol Handshake
>          Upgrade: WebSocket
>          Connection: Upgrade
>          WebSocket-Origin: http://localhost:9000
>          WebSocket-Location: ws://localhost:9999/
>          Sec-Websocket-Origin: http://localhost:9000
>          Sec-Websocket-Location: ws://localhost:9999/
>
>          5C368EF0F874025639911E2BC5F01412
>
> This all looks good except the string at the end (the digest) which has
> 32 characters whereas I think the client is expecting 16. I'm guessing
> the string is created as UTF16. Is there a way to get this to be 16
> characters?
>
> bob

If the client is expecting 16 bytes, then it wants the response in 
binary. You're converting it to hex text which is why you've got twice 
as many characters as you are expecting. just remove the digestToString 
bit and send the raw ubyte array.

You may or may not need to reverse the md5 as well.
Not sure if Endianess applies to a md5.

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk