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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.net;
     18 
     19 import android.content.Context;
     20 import android.util.Log;
     21 
     22 import com.android.org.conscrypt.ClientSessionContext;
     23 import com.android.org.conscrypt.FileClientSessionCache;
     24 import com.android.org.conscrypt.SSLClientSessionCache;
     25 
     26 import java.io.File;
     27 import java.io.IOException;
     28 
     29 import javax.net.ssl.SSLContext;
     30 import javax.net.ssl.SSLSessionContext;
     31 
     32 /**
     33  * File-based cache of established SSL sessions.  When re-establishing a
     34  * connection to the same server, using an SSL session cache can save some time,
     35  * power, and bandwidth by skipping directly to an encrypted stream.
     36  * This is a persistent cache which can span executions of the application.
     37  *
     38  * @see SSLCertificateSocketFactory
     39  */
     40 public final class SSLSessionCache {
     41     private static final String TAG = "SSLSessionCache";
     42     /* package */ final SSLClientSessionCache mSessionCache;
     43 
     44     /**
     45      * Installs a {@link SSLSessionCache} on a {@link SSLContext}. The cache will
     46      * be used on all socket factories created by this context (including factories
     47      * created before this call).
     48      *
     49      * @param cache the cache instance to install, or {@code null} to uninstall any
     50      *         existing cache.
     51      * @param context the context to install it on.
     52      * @throws IllegalArgumentException if the context does not support a session
     53      *         cache.
     54      *
     55      * @hide candidate for public API
     56      */
     57     public static void install(SSLSessionCache cache, SSLContext context) {
     58         SSLSessionContext clientContext = context.getClientSessionContext();
     59         if (clientContext instanceof ClientSessionContext) {
     60             ((ClientSessionContext) clientContext).setPersistentCache(
     61                     cache == null ? null : cache.mSessionCache);
     62         } else {
     63             throw new IllegalArgumentException("Incompatible SSLContext: " + context);
     64         }
     65     }
     66 
     67     /**
     68      * NOTE: This needs to be Object (and not SSLClientSessionCache) because apps
     69      * that build directly against the framework (and not the SDK) might not declare
     70      * a dependency on conscrypt. Javac will then has fail while resolving constructors.
     71      *
     72      * @hide For unit test use only
     73      */
     74     public SSLSessionCache(Object cache) {
     75         mSessionCache = (SSLClientSessionCache) cache;
     76     }
     77 
     78     /**
     79      * Create a session cache using the specified directory.
     80      * Individual session entries will be files within the directory.
     81      * Multiple instances for the same directory share data internally.
     82      *
     83      * @param dir to store session files in (created if necessary)
     84      * @throws IOException if the cache can't be opened
     85      */
     86     public SSLSessionCache(File dir) throws IOException {
     87         mSessionCache = FileClientSessionCache.usingDirectory(dir);
     88     }
     89 
     90     /**
     91      * Create a session cache at the default location for this app.
     92      * Multiple instances share data internally.
     93      *
     94      * @param context for the application
     95      */
     96     public SSLSessionCache(Context context) {
     97         File dir = context.getDir("sslcache", Context.MODE_PRIVATE);
     98         SSLClientSessionCache cache = null;
     99         try {
    100             cache = FileClientSessionCache.usingDirectory(dir);
    101         } catch (IOException e) {
    102             Log.w(TAG, "Unable to create SSL session cache in " + dir, e);
    103         }
    104         mSessionCache = cache;
    105     }
    106 }
    107