v/vlib/net/websocket/handshake.v

module websocket

fn (ws mut Client) read_handshake(seckey string){
	l.d("reading handshake...")
	mut bytes_read := 0
	max_buffer := 1024
	buffer_size := 1
	mut buffer := malloc(max_buffer)

	for bytes_read <= max_buffer {
		res := ws.read_from_server(buffer + bytes_read, buffer_size)
		if res == 0 || res == -1 { 
			l.f("read_handshake: Failed to read handshake.")
		}
		if buffer[bytes_read] == `\n` && buffer[bytes_read-1] == `\r` && buffer[bytes_read-2] == `\n` && buffer[bytes_read-3] == `\r` {
			break
		}
		bytes_read += buffer_size
	}
	buffer[max_buffer+1] = `\0`
	ws.handshake_handler(string(byteptr(buffer)), seckey)
}

fn (ws mut Client) handshake_handler(handshake_response, seckey string){
	l.d("handshake_handler:\r\n${handshake_response}")
	lines := handshake_response.split_into_lines()
	
	header := lines[0]
	if !header.starts_with("HTTP/1.1 101") && !header.starts_with("HTTP/1.0 101") {
		l.f("handshake_handler: invalid HTTP status response code")
	}

	for i in 1..lines.len {
		if lines[i].len <= 0 || lines[i] == "\r\n" {
			continue
		}
		keys := lines[i].split(":")

		match keys[0] {
			"Upgrade", "upgrade" {
				ws.flags << .has_upgrade
			}
			"Connection", "connection" {
				ws.flags << .has_connection
			}
			"Sec-WebSocket-Accept", "sec-websocket-accept" {
				l.d("comparing hashes")
				l.d("seckey: ${seckey}")
				challenge := create_key_challenge_response(seckey)
				l.d("challenge: ${challenge}")
				l.d("response: ${keys[1]}")
				if keys[1].trim_space() != challenge {
					l.e("handshake_handler: Sec-WebSocket-Accept header does not match computed sha1/base64 response.")
				}
				ws.flags << .has_accept
				unsafe {
					challenge.free()
				}
			} else {}
		}
		unsafe {
			keys.free()
		}
	}
	if ws.flags.len < 3 {
		ws.close(1002, "invalid websocket HTTP headers")
		l.e("invalid websocket HTTP headers")
	}
	l.i("handshake successful!")
	unsafe {
		handshake_response.free()
		lines.free()
		header.free()
	}
}