Bug: 482187 - HTTP headers should be case-insensitive for websockets

Optimising the WebSocket headers case insensitivity fix by hardcoding the headers as lower case and removing the need for .toLowerCase() calls

Signed-off-by: James Sutton <james.sutton@uk.ibm.com>

Author: jpwsutton

org.eclipse.paho.client.mqttv3/src/main/java/org/eclipse/paho/client/mqttv3/internal/websocket/WebSocketHandshake.java

@@ -34,8 +34,8 @@ public class WebSocketHandshake {
 	// Do not change: https://tools.ietf.org/html/rfc6455#section-1.3
 	private static final String ACCEPT_SALT = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 	private static final String SHA1_PROTOCOL = "SHA1";
-	private static final String HTTP_HEADER_SEC_WEBSOCKET_ACCEPT = "Sec-WebSocket-Accept";
-	private static final String HTTP_HEADER_UPGRADE = "Upgrade";
+	private static final String HTTP_HEADER_SEC_WEBSOCKET_ACCEPT = "sec-websocket-accept";
+	private static final String HTTP_HEADER_UPGRADE = "upgrade";
 	private static final String HTTP_HEADER_UPGRADE_WEBSOCKET = "websocket";
 	private static final String EMPTY = "";
 	private static final String LINE_SEPARATOR = "\r\n";
@@ -100,16 +100,16 @@ private void receiveHandshakeResponse(String key) throws IOException {
 		}
 		Map headerMap = getHeaders(responseLines);
 		String upgradeHeader = (String) headerMap.get(HTTP_HEADER_UPGRADE);
-		if(!upgradeHeader.toLowerCase().contains(HTTP_HEADER_UPGRADE_WEBSOCKET.toLowerCase())){
+		if(!upgradeHeader.toLowerCase().contains(HTTP_HEADER_UPGRADE_WEBSOCKET)){
 			throw new IOException("WebSocket Response header: Incorrect upgrade.");
 		}
 
-		if(!headerMap.containsKey(HTTP_HEADER_SEC_WEBSOCKET_ACCEPT.toLowerCase())){
+		if(!headerMap.containsKey(HTTP_HEADER_SEC_WEBSOCKET_ACCEPT)){
 			throw new IOException("WebSocket Response header: Missing Sec-WebSocket-Accept");
 		}
 
 		try {
-			verifyWebSocketKey(key, (String)headerMap.get(HTTP_HEADER_SEC_WEBSOCKET_ACCEPT.toLowerCase()));
+			verifyWebSocketKey(key, (String)headerMap.get(HTTP_HEADER_SEC_WEBSOCKET_ACCEPT));
 		} catch (NoSuchAlgorithmException e) {
 			throw new IOException(e.getMessage());
 		} catch (HandshakeFailedException e) {