Add support for HostnameVerifier

SMACK-586

Conflicts:
	smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java
	smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java

smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java

@@ -23,6 +23,7 @@ import org.jivesoftware.smack.util.DNSUtil;
 import org.jivesoftware.smack.util.dns.HostAddress;
 
 import javax.net.SocketFactory;
+import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
 import javax.security.auth.callback.CallbackHandler;
 
@@ -80,6 +81,8 @@ public class ConnectionConfiguration implements Cloneable {
     private boolean useDnsSrvRr = true;
     private SecurityMode securityMode = SecurityMode.enabled;
 
+    private HostnameVerifier hostnameVerifier;
+
     /**
      * Permanent store for the Roster, needed for roster versioning
      */
@@ -310,6 +313,29 @@ public class ConnectionConfiguration implements Cloneable {
         this.customSSLContext = context;
     }
 
+    /**
+     * Set the HostnameVerifier used to verify the hostname of SSLSockets used by XMPP connections
+     * created with this ConnectionConfiguration.
+     * 
+     * @param verifier
+     */
+    public void setHostnameVerifier(HostnameVerifier verifier) {
+        hostnameVerifier = verifier;
+    }
+
+    /**
+     * Returns the configured HostnameVerifier of this ConnectionConfiguration or the Smack default
+     * HostnameVerifier configured with
+     * {@link SmackConfiguration#setDefaultHostnameVerifier(HostnameVerifier)}.
+     * 
+     * @return a configured HostnameVerifier or <code>null</code>
+     */
+    public HostnameVerifier getHostnameVerifier() {
+        if (hostnameVerifier != null)
+            return hostnameVerifier;
+        return SmackConfiguration.getDefaultHostnameVerifier();
+    }
+
     /**
      * Returns true if the connection is going to use stream compression. Stream compression
      * will be requested after TLS was established (if TLS was enabled) and only if the server

smack-core/src/main/java/org/jivesoftware/smack/SmackConfiguration.java

@@ -31,6 +31,8 @@ import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import javax.net.ssl.HostnameVerifier;
+
 import org.jivesoftware.smack.compression.Java7ZlibInputOutputStream;
 import org.jivesoftware.smack.compression.XMPPInputOutputStream;
 import org.jivesoftware.smack.initializer.SmackInitializer;
@@ -178,6 +180,8 @@ public final class SmackConfiguration {
      */
     private static ParsingExceptionCallback defaultCallback = new ExceptionThrowingCallback();
 
+    private static HostnameVerifier defaultHostnameVerififer;
+
     /**
      * Returns the Smack version information, eg "1.3.0".
      * 
@@ -319,6 +323,25 @@ public final class SmackConfiguration {
         return res;
     }
 
+    /**
+     * Set the default HostnameVerifier that will be used by XMPP connections to verify the hostname
+     * of a TLS certificate. XMPP connections are able to overwrite this settings by supplying a
+     * HostnameVerifier in their ConnecitonConfiguration with
+     * {@link ConnectionConfiguration#setHostnameVerifier(HostnameVerifier)}.
+     */
+    public static void setDefaultHostnameVerifier(HostnameVerifier verifier) {
+        defaultHostnameVerififer = verifier;
+    }
+
+    /**
+     * Get the default HostnameVerifier
+     *
+     * @return the default HostnameVerifier or <code>null</code> if none was set
+     */
+    static HostnameVerifier getDefaultHostnameVerifier() {
+        return defaultHostnameVerififer;
+    }
+
     public static void processConfigFile(InputStream cfgFileStream,
                     Collection<Exception> exceptions) throws Exception {
         processConfigFile(cfgFileStream, exceptions, SmackConfiguration.class.getClassLoader());

smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java

@@ -35,6 +35,7 @@ import org.jivesoftware.smack.parsing.ParsingExceptionCallback;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.dns.HostAddress;
 
+import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
@@ -61,6 +62,7 @@ import java.net.Socket;
 import java.security.KeyStore;
 import java.security.Provider;
 import java.security.Security;
+import java.security.cert.CertificateException;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedList;
@@ -647,14 +649,21 @@ public class XMPPTCPConnection extends XMPPConnection {
         // Initialize the reader and writer with the new secured version
         initReaderAndWriter();
 
+        final SSLSocket sslSocket = (SSLSocket) socket;
         try {
             // Proceed to do the handshake
-            ((SSLSocket) socket).startHandshake();
+            sslSocket.startHandshake();
         }
         catch (IOException e) {
             setConnectionException(e);
             throw e;
         }
+
+        final HostnameVerifier verifier = getConfiguration().getHostnameVerifier();
+        if (verifier != null && !verifier.verify(getServiceName(), sslSocket.getSession())) {
+            throw new CertificateException("Hostname verification of certificate failed. Certificate does not authenticate " + getServiceName());
+        }
+
         //if (((SSLSocket) socket).getWantClientAuth()) {
         //    System.err.println("XMPPConnection wants client auth");
         //}