Remote input encryption changes for GFE 2.1.1

moonlight-common/src/com/limelight/nvstream/NvConnection.java

@@ -4,6 +4,7 @@ import java.io.IOException;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
@@ -47,6 +48,7 @@ public class NvConnection {
 	private AudioRenderer audioRenderer;
 	private String localDeviceName;
 	private SecretKey riKey;
+	private int riKeyId;
 	
 	private ThreadPoolExecutor threadPool;
 	
@@ -66,6 +68,8 @@ public class NvConnection {
 			e.printStackTrace();
 		}
 		
+		this.riKeyId = generateRiKeyId();
+		
 		this.threadPool = new ThreadPoolExecutor(1, 1, Long.MAX_VALUE, TimeUnit.DAYS,
 				new LinkedBlockingQueue<Runnable>(), new ThreadPoolExecutor.DiscardPolicy());
 	}
@@ -79,6 +83,10 @@ public class NvConnection {
 		return keyGen.generateKey();
 	}
 	
+	private static int generateRiKeyId() {
+		return new SecureRandom().nextInt();
+	}
+	
 	public void stop()
 	{
 		threadPool.shutdownNow();
@@ -104,8 +112,8 @@ public class NvConnection {
 	{
 		NvHTTP h = new NvHTTP(hostAddr, uniqueId, localDeviceName, cryptoProvider);
 		
-		if (h.getServerVersion().startsWith("1.")) {
+		if (!h.getServerVersion().startsWith("3.")) {
-			listener.displayMessage("Limelight now requires GeForce Experience 2.0.1 or later. Please upgrade GFE on your PC and try again.");
+			listener.displayMessage("Limelight now requires GeForce Experience 2.1.1 or later. Please upgrade GFE on your PC and try again.");
 			return false;
 		}
 		
@@ -123,7 +131,7 @@ public class NvConnection {
 		// If there's a game running, resume it
 		if (h.getCurrentGame() != 0) {
 			try {
-				if (h.getCurrentGame() == app.getAppId() && !h.resumeApp(riKey)) {
+				if (h.getCurrentGame() == app.getAppId() && !h.resumeApp(riKey, riKeyId)) {
 					listener.displayMessage("Failed to resume existing session");
 					return false;
 				} else if (h.getCurrentGame() != app.getAppId()) {
@@ -169,7 +177,8 @@ public class NvConnection {
 			throws IOException, XmlPullParserException {
 		// Launch the app since it's not running
 		int gameSessionId = h.launchApp(app.getAppId(), config.getWidth(),
-				config.getHeight(), config.getRefreshRate(), riKey, config.getSops());
+				config.getHeight(), config.getRefreshRate(), riKey, config.getSops(),
+				riKeyId);
 		if (gameSessionId == 0) {
 			listener.displayMessage("Failed to launch application");
 			return false;
@@ -213,7 +222,7 @@ public class NvConnection {
 		// it to the instance variable once the object is properly initialized.
 		// This avoids the race where inputStream != null but inputStream.initialize()
 		// has not returned yet.
-		NvController tempController = new NvController(hostAddr, riKey);
+		NvController tempController = new NvController(hostAddr, riKey, riKeyId);
 		tempController.initialize();
 		inputStream = tempController;
 		return true;

moonlight-common/src/com/limelight/nvstream/http/NvHTTP.java

@@ -27,7 +27,6 @@ import com.limelight.nvstream.http.PairingManager.PairState;
 public class NvHTTP {
 	private String uniqueId;
 	private PairingManager pm;
-	private LimelightCryptoProvider cryptoProvider;
 	private InetAddress address;
 
 	public static final int PORT = 47984;
@@ -39,7 +38,6 @@ public class NvHTTP {
 	
 	public NvHTTP(InetAddress host, String uniqueId, String deviceName, LimelightCryptoProvider cryptoProvider) {
 		this.uniqueId = uniqueId;
-		this.cryptoProvider = cryptoProvider;
 		this.address = host;
 		
 		String safeAddress;
@@ -252,20 +250,33 @@ public class NvHTTP {
 		openHttpConnection(baseUrl + "/unpair?uniqueid=" + uniqueId);
 	}
 
-	public int launchApp(int appId, int width, int height, int refreshRate, SecretKey inputKey, boolean sops) throws IOException, XmlPullParserException {
+	final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
+	private static String bytesToHex(byte[] bytes) {
+	    char[] hexChars = new char[bytes.length * 2];
+	    for ( int j = 0; j < bytes.length; j++ ) {
+	        int v = bytes[j] & 0xFF;
+	        hexChars[j * 2] = hexArray[v >>> 4];
+	        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+	    }
+	    return new String(hexChars);
+	}
+	
+	public int launchApp(int appId, int width, int height, int refreshRate, SecretKey inputKey, boolean sops, int riKeyId) throws IOException, XmlPullParserException {
 		InputStream in = openHttpConnection(baseUrl +
 			"/launch?uniqueid=" + uniqueId +
 			"&appid=" + appId +
 			"&mode=" + width + "x" + height + "x" + refreshRate +
 			"&additionalStates=1&sops=" + (sops ? 1 : 0) +
-			"&rikey="+cryptoProvider.encodeBase64String(inputKey.getEncoded()));
+			"&rikey="+bytesToHex(inputKey.getEncoded()) +
+			"&rikeyid="+riKeyId);
 		String gameSession = getXmlString(in, "gamesession");
 		return Integer.parseInt(gameSession);
 	}
 	
-	public boolean resumeApp(SecretKey inputKey) throws IOException, XmlPullParserException {
+	public boolean resumeApp(SecretKey inputKey, int riKeyId) throws IOException, XmlPullParserException {
 		InputStream in = openHttpConnection(baseUrl + "/resume?uniqueid=" + uniqueId +
-				"&rikey="+cryptoProvider.encodeBase64String(inputKey.getEncoded()));
+				"&rikey="+bytesToHex(inputKey.getEncoded()) +
+				"&rikeyid="+riKeyId);
 		String resume = getXmlString(in, "resume");
 		return Integer.parseInt(resume) != 0;
 	}

moonlight-common/src/com/limelight/nvstream/input/NvController.java

@@ -5,6 +5,7 @@ import java.io.OutputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.Socket;
+import java.nio.ByteBuffer;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
@@ -26,16 +27,17 @@ public class NvController {
 	private OutputStream out;
 	private Cipher riCipher;
 	
-	
+	public NvController(InetAddress host, SecretKey riKey, int riKeyId)
-	private final static byte[] ENCRYPTED_HEADER = new byte[] {0x00, 0x00, 0x00, 0x20};
-	
-	public NvController(InetAddress host, SecretKey riKey)
 	{
 		this.host = host;
 		try {
 			// This cipher is guaranteed to be supported
 			this.riCipher = Cipher.getInstance("AES/CBC/NoPadding");
-			this.riCipher.init(Cipher.ENCRYPT_MODE, riKey, new IvParameterSpec(new byte[16]));
+			
+			ByteBuffer bb = ByteBuffer.allocate(16);
+			bb.putInt(riKeyId);
+			
+			this.riCipher.init(Cipher.ENCRYPT_MODE, riKey, new IvParameterSpec(bb.array()));
 		} catch (NoSuchAlgorithmException e) {
 			e.printStackTrace();
 		} catch (NoSuchPaddingException e) {
@@ -62,23 +64,51 @@ public class NvController {
 		} catch (IOException e) {}
 	}
 	
+	private static int getPaddedSize(int length) {
+		return ((length + 15) / 16) * 16;
+	}
+	
+	private static byte[] padData(byte[] data) {
+		// This implements the PKCS7 padding algorithm
+		
+		if ((data.length % 16) == 0) {
+			// Already a multiple of 16
+			return data;
+		}
+		
+		byte[] padded = Arrays.copyOf(data, getPaddedSize(data.length));
+		byte paddingByte = (byte)(16 - (data.length % 16));
+		
+		for (int i = data.length; i < padded.length; i++) {
+			padded[i] = paddingByte;
+		}
+		
+		return padded;
+	}
+	
 	private byte[] encryptAesInputData(byte[] data) throws Exception {
-		// Input data is rounded to units of 32 bytes
+		return riCipher.update(padData(data));
-		byte[] blockRoundedData = Arrays.copyOf(data, 32);
-		return riCipher.update(blockRoundedData);
 	}
 	
 	private void sendPacket(InputPacket packet) throws IOException {
-		out.write(ENCRYPTED_HEADER);
+		byte[] toWire = packet.toWire();
-		byte[] encryptedInput;
+		
+		// Pad to 16 byte chunks
+		int paddedLength = getPaddedSize(toWire.length);
+		
+		// Allocate a byte buffer to represent the final packet
+		ByteBuffer bb = ByteBuffer.allocate(4 + paddedLength);
+		bb.putInt(paddedLength);
 		try {
-			encryptedInput = encryptAesInputData(packet.toWire());
+			bb.put(encryptAesInputData(toWire));
 		} catch (Exception e) {
 			// Should never happen
 			e.printStackTrace();
 			return;
 		}
-		out.write(encryptedInput);
+		
+		// Send the packet
+		out.write(bb.array());
 		out.flush();
 	}