// Hixie 75 does not contain these headers while Hixie 76 does
boolean isHixie76 = req.containsHeader(SEC_WEBSOCKET_KEY1) && req.containsHeader(SEC_WEBSOCKET_KEY2);
// Create the WebSocket handshake response.
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, new HttpResponseStatus(101,
isHixie76 ? "WebSocket Protocol Handshake" : "Web Socket Protocol Handshake"));
res.addHeader(Names.UPGRADE, WEBSOCKET);
res.addHeader(CONNECTION, Values.UPGRADE);
// Fill in the headers and contents depending on handshake method.
if (isHixie76) {
// New handshake method with a challenge:
res.addHeader(SEC_WEBSOCKET_ORIGIN, req.getHeader(ORIGIN));
res.addHeader(SEC_WEBSOCKET_LOCATION, getWebSocketUrl());
String subprotocols = req.getHeader(SEC_WEBSOCKET_PROTOCOL);
if (subprotocols != null) {
String selectedSubprotocol = selectSubprotocol(subprotocols);
if (selectedSubprotocol == null) {
throw new WebSocketHandshakeException("Requested subprotocol(s) not supported: " + subprotocols);
} else {
res.addHeader(SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
setSelectedSubprotocol(selectedSubprotocol);
}
}
// Calculate the answer of the challenge.
String key1 = req.getHeader(SEC_WEBSOCKET_KEY1);
String key2 = req.getHeader(SEC_WEBSOCKET_KEY2);
int a = (int) (Long.parseLong(key1.replaceAll("[^0-9]", "")) / key1.replaceAll("[^ ]", "").length());
int b = (int) (Long.parseLong(key2.replaceAll("[^0-9]", "")) / key2.replaceAll("[^ ]", "").length());
long c = req.getContent().readLong();
ChannelBuffer input = ChannelBuffers.buffer(16);
input.writeInt(a);
input.writeInt(b);
input.writeLong(c);
res.setContent(WebSocketUtil.md5(input));
} else {
// Old Hixie 75 handshake method with no challenge:
res.addHeader(WEBSOCKET_ORIGIN, req.getHeader(ORIGIN));
res.addHeader(WEBSOCKET_LOCATION, getWebSocketUrl());
String protocol = req.getHeader(WEBSOCKET_PROTOCOL);
if (protocol != null) {
res.addHeader(WEBSOCKET_PROTOCOL, selectSubprotocol(protocol));
}
}
ChannelFuture future = channel.write(res);