1 /*
   2  * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.security.pkcs11;
  27 
  28 import java.util.*;
  29 import java.lang.ref.*;
  30 
  31 import java.security.Key;
  32 
  33 import sun.security.util.Cache;
  34 
  35 /**
  36  * Key to P11Key translation cache. The PKCS#11 token can only perform
  37  * operations on keys stored on the token (permanently or temporarily). That
  38  * means that in order to allow the PKCS#11 provider to use keys from other
  39  * providers, we need to transparently convert them to P11Keys. The engines
  40  * do that using (Secret)KeyFactories, which in turn use this class as a
  41  * cache.
  42  *
  43  * There are two KeyCache instances per provider, one for secret keys and
  44  * one for public and private keys.
  45  *
  46  * @author  Andreas Sterbenz
  47  * @since   1.5
  48  */
  49 final class KeyCache {
  50 
  51     private final Cache<IdentityWrapper, P11Key> strongCache;
  52 
  53     private WeakReference<Map<Key,P11Key>> cacheReference;
  54 
  55     KeyCache() {
  56         strongCache = Cache.newHardMemoryCache(16);
  57     }
  58 
  59     private static final class IdentityWrapper {
  60         final Object obj;
  61         IdentityWrapper(Object obj) {
  62             this.obj = obj;
  63         }
  64         public boolean equals(Object o) {
  65             if (this == o) {
  66                 return true;
  67             }
  68             if (o instanceof IdentityWrapper == false) {
  69                 return false;
  70             }
  71             IdentityWrapper other = (IdentityWrapper)o;
  72             return this.obj == other.obj;
  73         }
  74         public int hashCode() {
  75             return System.identityHashCode(obj);
  76         }
  77     }
  78 
  79     synchronized P11Key get(Key key) {
  80         P11Key p11Key = strongCache.get(new IdentityWrapper(key));
  81         if (p11Key != null) {
  82             return p11Key;
  83         }
  84         Map<Key,P11Key> map =
  85                 (cacheReference == null) ? null : cacheReference.get();
  86         if (map == null) {
  87             return null;
  88         }
  89         return map.get(key);
  90     }
  91 
  92     synchronized void put(Key key, P11Key p11Key) {
  93         strongCache.put(new IdentityWrapper(key), p11Key);
  94         Map<Key,P11Key> map =
  95                 (cacheReference == null) ? null : cacheReference.get();
  96         if (map == null) {
  97             map = new IdentityHashMap<>();
  98             cacheReference = new WeakReference<>(map);
  99         }
 100         map.put(key, p11Key);
 101     }
 102 
 103 }