Add cert pinning during pairing

moonlight-common/src/main/java/com/limelight/nvstream/ConnectionContext.java

@@ -1,9 +1,12 @@
 package com.limelight.nvstream;
 
+import java.security.cert.X509Certificate;
+
 import javax.crypto.SecretKey;
 
 public class ConnectionContext {
 	public String serverAddress;
+	public X509Certificate serverCert;
 	public StreamConfiguration streamConfig;
 	public NvConnectionListener connListener;
 	public SecretKey riKey;

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

@@ -6,6 +6,7 @@ import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
+import java.security.cert.X509Certificate;
 import java.util.concurrent.Semaphore;
 
 import javax.crypto.KeyGenerator;
@@ -33,14 +34,15 @@ public class NvConnection {
 	private static Semaphore connectionAllowed = new Semaphore(1);
 	private final boolean isMonkey;
 	
-	public NvConnection(String host, String uniqueId, StreamConfiguration config, LimelightCryptoProvider cryptoProvider)
+	public NvConnection(String host, String uniqueId, StreamConfiguration config, LimelightCryptoProvider cryptoProvider, X509Certificate serverCert)
 	{		
 		this.host = host;
 		this.cryptoProvider = cryptoProvider;
 		this.uniqueId = uniqueId;
-		
+
 		this.context = new ConnectionContext();
 		this.context.streamConfig = config;
+		this.context.serverCert = serverCert;
 		try {
 			// This is unique per connection
 			this.context.riKey = generateRiAesKey();
@@ -83,7 +85,7 @@ public class NvConnection {
 	
 	private boolean startApp() throws XmlPullParserException, IOException
 	{
-		NvHTTP h = new NvHTTP(context.serverAddress, uniqueId, null, cryptoProvider);
+		NvHTTP h = new NvHTTP(context.serverAddress, uniqueId, context.serverCert, cryptoProvider);
 
 		String serverInfo = h.getServerInfo();
 		

moonlight-common/src/main/java/com/limelight/nvstream/http/ComputerDetails.java

@@ -1,5 +1,6 @@
 package com.limelight.nvstream.http;
 
+import java.security.cert.X509Certificate;
 import java.util.UUID;
 
 
@@ -15,6 +16,7 @@ public class ComputerDetails {
 	public String remoteAddress;
 	public String manualAddress;
 	public String macAddress;
+	public X509Certificate serverCert;
 
 	// Transient attributes
 	public State state;
@@ -52,6 +54,9 @@ public class ComputerDetails {
 		if (details.macAddress != null && !details.macAddress.equals("00:00:00:00:00:00")) {
 			this.macAddress = details.macAddress;
 		}
+		if (details.serverCert != null) {
+			this.serverCert = details.serverCert;
+		}
 		this.pairState = details.pairState;
 		this.runningGameId = details.runningGameId;
 		this.rawAppList = details.rawAppList;

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

@@ -13,6 +13,7 @@ import java.net.URISyntaxException;
 import java.security.Principal;
 import java.security.PrivateKey;
 import java.security.SecureRandom;
+import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.util.LinkedList;
 import java.util.ListIterator;
@@ -24,6 +25,7 @@ import java.util.concurrent.TimeUnit;
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLHandshakeException;
 import javax.net.ssl.SSLSession;
 import javax.net.ssl.TrustManager;
 import javax.net.ssl.X509KeyManager;
@@ -47,7 +49,6 @@ import com.squareup.okhttp.ResponseBody;
 public class NvHTTP {
 	private String uniqueId;
 	private PairingManager pm;
-	private String address;
 
 	public static final int HTTPS_PORT = 47984;
 	public static final int HTTP_PORT = 47989;
@@ -63,20 +64,31 @@ public class NvHTTP {
 	private OkHttpClient httpClient = new OkHttpClient();
 	private OkHttpClient httpClientWithReadTimeout;
 		
-	private TrustManager[] trustAllCerts;
-	private KeyManager[] ourKeyman;
+	private TrustManager[] trustManager;
+	private KeyManager[] keyManager;
 	
-	private void initializeHttpState(final LimelightCryptoProvider cryptoProvider) {
-		trustAllCerts = new TrustManager[] { 
+	private void initializeHttpState(final X509Certificate serverCert, final LimelightCryptoProvider cryptoProvider) {
+		trustManager = new TrustManager[] {
 				new X509TrustManager() {
 					public X509Certificate[] getAcceptedIssuers() { 
 						return new X509Certificate[0]; 
 					}
-					public void checkClientTrusted(X509Certificate[] certs, String authType) {}
-					public void checkServerTrusted(X509Certificate[] certs, String authType) {}
+					public void checkClientTrusted(X509Certificate[] certs, String authType) {
+						throw new IllegalStateException("Should never be called");
+					}
+					public void checkServerTrusted(X509Certificate[] certs, String authType) throws CertificateException {
+						if (certs.length != 1) {
+							throw new CertificateException("Invalid certificate chain length: "+certs.length);
+						}
+
+						// Check the server certificate if we've paired to this host
+						if (serverCert != null && !certs[0].equals(serverCert)) {
+							throw new CertificateException("Certificate mismatch");
+						}
+					}
 				}};
 
-		ourKeyman = new KeyManager[] {
+		keyManager = new KeyManager[] {
 				new X509KeyManager() {
 					public String chooseClientAlias(String[] keyTypes,
 							Principal[] issuers, Socket socket) { return "Limelight-RSA"; }
@@ -107,11 +119,10 @@ public class NvHTTP {
 		httpClientWithReadTimeout.setReadTimeout(READ_TIMEOUT, TimeUnit.MILLISECONDS);
 	}
 	
-	public NvHTTP(String address, String uniqueId, String deviceName, LimelightCryptoProvider cryptoProvider) throws IOException {
+	public NvHTTP(String address, String uniqueId, X509Certificate serverCert, LimelightCryptoProvider cryptoProvider) throws IOException {
 		this.uniqueId = uniqueId;
-		this.address = address;
-		
-		initializeHttpState(cryptoProvider);
+
+		initializeHttpState(serverCert, cryptoProvider);
 
 		try {
 			// The URI constructor takes care of escaping IPv6 literals
@@ -186,8 +197,20 @@ public class NvHTTP {
 		//
 		
 		try {
-			resp = openHttpConnectionToString(baseUrlHttps + "/serverinfo?"+buildUniqueIdUuidString(), true);
-			
+			try {
+				resp = openHttpConnectionToString(baseUrlHttps + "/serverinfo?"+buildUniqueIdUuidString(), true);
+			} catch (SSLHandshakeException e) {
+			    // Detect if we failed due to a server cert mismatch
+				if (e.getCause() instanceof CertificateException) {
+                    // Jump to the GfeHttpResponseException exception handler to retry
+                    // over HTTP which will allow us to pair again to update the cert
+                    throw new GfeHttpResponseException(401, "Server certificate mismatch");
+                }
+                else {
+				    throw e;
+                }
+			}
+
 			// This will throw an exception if the request came back with a failure status.
 			// We want this because it will throw us into the HTTP case if the client is unpaired.
 			getServerVersion(resp);
@@ -246,7 +269,7 @@ public class NvHTTP {
 		// to avoid the SSLv3 fallback that causes connection failures
 		try {
 			SSLContext sc = SSLContext.getInstance("TLSv1");
-			sc.init(ourKeyman, trustAllCerts, new SecureRandom());
+			sc.init(keyManager, trustManager, new SecureRandom());
 			
 			client.setSslSocketFactory(sc.getSocketFactory());
 		} catch (Exception e) {
@@ -444,9 +467,9 @@ public class NvHTTP {
 		}
 		return null;
 	}
-	
-	public PairingManager.PairState pair(String serverInfo, String pin) throws Exception {
-		return pm.pair(serverInfo, pin);
+
+	public PairingManager getPairingManager() {
+		return pm;
 	}
 	
 	public static LinkedList<NvApp> getAppListByReader(Reader r) throws XmlPullParserException, IOException {

moonlight-common/src/main/java/com/limelight/nvstream/http/PairingManager.java

@@ -29,6 +29,8 @@ public class PairingManager {
 	private X509Certificate cert;
 	private SecretKey aesKey;
 	private byte[] pemCertBytes;
+
+	private X509Certificate serverCert;
 	
 	public enum PairState {
 		NOT_PAIRED,
@@ -160,10 +162,14 @@ public class PairingManager {
 		
 		return PairState.PAIRED;
 	}
+
+	public X509Certificate getPairedCert() {
+		return serverCert;
+	}
 	
 	public PairState pair(String serverInfo, String pin) throws MalformedURLException, IOException, XmlPullParserException, CertificateException, InvalidKeyException, NoSuchAlgorithmException, SignatureException, ShortBufferException, IllegalBlockSizeException, BadPaddingException, NoSuchPaddingException {
 		PairingHashAlgorithm hashAlgo;
-		
+
 		int serverMajorVersion = http.getServerMajorVersion(serverInfo);
 		LimeLog.info("Pairing with server generation: "+serverMajorVersion);
 		if (serverMajorVersion >= 7) {
@@ -191,7 +197,9 @@ public class PairingManager {
 		if (!NvHTTP.getXmlString(getCert, "paired").equals("1")) {
 			return PairState.FAILED;
 		}
-		X509Certificate serverCert = extractPlainCert(getCert);
+
+		// Save this cert for retrieval later for pinning
+		serverCert = extractPlainCert(getCert);
 		if (serverCert == null) {
 			// Attempting to pair while another device is pairing will cause GFE
 			// to give an empty cert in the response.
@@ -271,7 +279,7 @@ public class PairingManager {
 			http.openHttpConnectionToString(http.baseUrlHttp + "/unpair?"+http.buildUniqueIdUuidString(), true);
 			return PairState.FAILED;
 		}
-		
+
 		return PairState.PAIRED;
 	}