oc_framework/src/com/owncloud/android/oc_framework/network/ServerNameIndicator.java

   1 /* ownCloud webDAV Library for Android is available under MIT license
   2  *   Copyright (C) 2014 ownCloud (http://www.owncloud.org/)
   3  *
   4  *   Permission is hereby granted, free of charge, to any person obtaining a copy
   5  *   of this software and associated documentation files (the "Software"), to deal
   6  *   in the Software without restriction, including without limitation the rights
   7  *   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  *   copies of the Software, and to permit persons to whom the Software is
   9  *   furnished to do so, subject to the following conditions:
  10  *
  11  *   The above copyright notice and this permission notice shall be included in
  12  *   all copies or substantial portions of the Software.
  13  *
  14  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16  *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  18  *   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  19  *   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  20  *   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21  *   THE SOFTWARE.
  22  *
  23  */
  24
  25 package com.owncloud.android.oc_framework.network;
  26
  27 import java.lang.ref.WeakReference;
  28 import java.lang.reflect.InvocationTargetException;
  29 import java.lang.reflect.Method;
  30 import java.util.concurrent.atomic.AtomicReference;
  31
  32 import javax.net.ssl.SSLSocket;
  33
  34 import android.util.Log;
  35
  36
  37 /**
  38  * Enables the support of Server Name Indication if existing
  39  * in the underlying network implementation.
  40  *
  41  * Build as a singleton.
  42  *
  43  * @author David A. Velasco
  44  */
  45 public class ServerNameIndicator {
  46
  47         private static final String TAG = ServerNameIndicator.class.getSimpleName();
  48
  49         private static final AtomicReference<ServerNameIndicator> mSingleInstance = new AtomicReference<ServerNameIndicator>();
  50
  51         private static final String METHOD_NAME = "setHostname";
  52
  53         private final WeakReference<Class<?>> mSSLSocketClassRef;
  54         private final WeakReference<Method> mSetHostnameMethodRef;
  55
  56
  57         /**
  58          * Private constructor, class is a singleton.
  59          *
  60          * @param sslSocketClass                Underlying implementation class of {@link SSLSocket} used to connect with the server.
  61          * @param setHostnameMethod             Name of the method to call to enable the SNI support.
  62          */
  63         private ServerNameIndicator(Class<?> sslSocketClass, Method setHostnameMethod) {
  64                 mSSLSocketClassRef = new WeakReference<Class<?>>(sslSocketClass);
  65                 mSetHostnameMethodRef = (setHostnameMethod == null) ? null : new WeakReference<Method>(setHostnameMethod);
  66         }
  67
  68
  69         /**
  70          * Calls the {@code #setHostname(String)} method of the underlying implementation
  71          * of {@link SSLSocket} if exists.
  72          *
  73          * Creates and initializes the single instance of the class when needed
  74          *
  75          * @param hostname              The name of the server host of interest.
  76          * @param sslSocket     Client socket to connect with the server.
  77          */
  78         public static void setServerNameIndication(String hostname, SSLSocket sslSocket) {
  79                 final Method setHostnameMethod = getMethod(sslSocket);
  80                 if (setHostnameMethod != null) {
  81                         try {
  82                                 setHostnameMethod.invoke(sslSocket, hostname);
  83                                 Log.i(TAG, "SNI done, hostname: " + hostname);
  84
  85                         } catch (IllegalArgumentException e) {
  86                                 Log.e(TAG, "Call to SSLSocket#setHost(String) failed ", e);
  87
  88                         } catch (IllegalAccessException e) {
  89                                 Log.e(TAG, "Call to SSLSocket#setHost(String) failed ", e);
  90
  91                         } catch (InvocationTargetException e) {
  92                                 Log.e(TAG, "Call to SSLSocket#setHost(String) failed ", e);
  93                         }
  94                 } else {
  95                         Log.i(TAG, "SNI not supported");
  96                 }
  97         }
  98
  99
 100         /**
 101          * Gets the method to invoke trying to minimize the effective
 102          * application of reflection.
 103          *
 104          * @param       sslSocket               Instance of the SSL socket to use in connection with server.
 105          * @return                                      Method to call to indicate the server name of interest to the server.
 106          */
 107         private static Method getMethod(SSLSocket sslSocket) {
 108                 final Class<?> sslSocketClass = sslSocket.getClass();
 109                 final ServerNameIndicator instance = mSingleInstance.get();
 110                 if (instance == null) {
 111                         return initFrom(sslSocketClass);
 112
 113                 } else if (instance.mSSLSocketClassRef.get() != sslSocketClass) {
 114                         // the underlying class changed
 115                         return initFrom(sslSocketClass);
 116
 117                 } else if (instance.mSetHostnameMethodRef == null) {
 118                         // SNI not supported
 119                         return null;
 120
 121                 } else {
 122                         final Method cachedSetHostnameMethod = instance.mSetHostnameMethodRef.get();
 123                         return (cachedSetHostnameMethod == null) ? initFrom(sslSocketClass) : cachedSetHostnameMethod;
 124                 }
 125         }
 126
 127
 128         /**
 129          * Singleton initializer.
 130          *
 131          * Uses reflection to extract and 'cache' the method to invoke to indicate the desited host name to the server side.
 132          *
 133          * @param       sslSocketClass          Underlying class providing the implementation of {@link SSLSocket}.
 134          * @return                                              Method to call to indicate the server name of interest to the server.
 135          */
 136         private static Method initFrom(Class<?> sslSocketClass) {
 137         Log.i(TAG, "SSLSocket implementation: " + sslSocketClass.getCanonicalName());
 138                 Method setHostnameMethod = null;
 139                 try {
 140                         setHostnameMethod = sslSocketClass.getMethod(METHOD_NAME, String.class);
 141                 } catch (SecurityException e) {
 142                         Log.e(TAG, "Could not access to SSLSocket#setHostname(String) method ", e);
 143
 144                 } catch (NoSuchMethodException e) {
 145                         Log.i(TAG, "Could not find SSLSocket#setHostname(String) method - SNI not supported");
 146                 }
 147                 mSingleInstance.set(new ServerNameIndicator(sslSocketClass, setHostnameMethod));
 148                 return setHostnameMethod;
 149         }
 150
 151 }