c# 4.0 - C# - Websocket - Sending Message Back To Client -

i've been working on c# web socket server 24 hours.

i've figured out how complete handshake , connection initialized.

also i've figured out how take byte[] data , decode it's original string.

but i'm stuck , looking help.

i can't seem figure out how put proper data structure , send client. if send original data received websocket on client-side tell data cannot masked (which why needs decoded).

so basically, i'm asking in short how structure response data send websocket client?

i've been using http://tools.ietf.org/html/rfc6455 resource research.

please keep in mind i'm using regular socket this.

here decode code:

if (databuffer.length > 0) {     if (databuffer[0] == 129)     {         int msg_length = databuffer[1] - 128;         if (msg_length <= 125)         {             // msg ready decode.             log.info("message length: " + msg_length);               byte[] decoded = new byte[databuffer.length];             byte[] encoded = new byte[databuffer.length - 6];              array.copy(databuffer, 6, encoded, 0, msg_length);              byte[] key = new byte[4] { databuffer[2], databuffer[3], databuffer[4], databuffer[5] };             (int = 0; < encoded.length; i++)             {                 decoded[i] = (byte)(encoded[i] ^ key[i % 4]);             }              log.info("msg: " + encoding.utf8.getstring(decoded));              byte[] return_msg = new byte[decoded.length + 8];              return_msg[0] = 1;             return_msg[1] = 0;             return_msg[2] = 0;             return_msg[3] = 0;             // op code             return_msg[4] = 0x1;             return_msg[5] = 0x0;             return_msg[6] = 0x0;             return_msg[7] = 0x0;              array.copy(decoded, 0, return_msg, 8, decoded.length);              socket.send(return_msg);         }         else if (msg_length == 126)         {             // longer message             msg_length = databuffer[2] + databuffer[3];              log.info("message length: " + msg_length);              byte[] key = new byte[4] { databuffer[4], databuffer[5], databuffer[6], databuffer[7] };              byte[] decoded = new byte[databuffer.length];             byte[] encoded = new byte[databuffer.length - 8];              array.copy(databuffer, 8, encoded, 0, msg_length);              (int = 0; < encoded.length; i++)             {                 decoded[i] = (byte)(encoded[i] ^ key[i % 4]);             }              log.info("msg: " + encoding.utf8.getstring(decoded));             byte[] return_msg = new byte[decoded.length + 4];              return_msg[0] = 129;             return_msg[1] = 0;             return_msg[2] = 0;             return_msg[3] = 0;              array.copy(decoded,0,return_msg,4,decoded.length);              socket.send(return_msg);         }         else if (msg_length == 127)         {             // huge message:             log.info("big message");         }     }  } 

take 2 articles writing c# websocket servers:

https://developer.mozilla.org/en-us/docs/websockets/writing_websocket_servers

https://developer.mozilla.org/en-us/docs/websockets/writing_websocket_server

it seems both same article, not! in this part of first link have explanation how build frames.

update

the first byte contains several information:

• fin :indicates frame contains complete message.
• rsv1: option 1
• rsv2: option 2
• rsv3: option 3
• optcode: indicates type of frame.

if want send text message smaller 125 bytes, lets message has 90 bytes, in first byte put bit 0 1(more significant), next 3 0, unless want enable options, , next 4 0001, indicating text frame. first bye 10000001, or 129.

now in second byte, first bit indicates if frame masked. don't mask frames server client, set 0. next 7 bits indicates rather length, or type of frame length. because sending small frame, can indicate value 125 in 7 bits. because frame length 90 bytes, second byte of header 01011010, or 90.

so when sending server client text frame of 90 byes, first 2 bytes conforming header 129 , 90. rest of message 90 bytes of utf8 encoded bytes.

if frame longer 125 bytes, length of header, check spec. if frame need masked (like frames client), first 4 bytes of body contain masking key. see there tidbits cope with, recommend read spec : https://tools.ietf.org/html/rfc6455