1 /* 2 * Copyright (c) 2014, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 package java.util; 25 26 /** 27 * Implementation of SystemRandom for Windows Crypto API. 28 */ 29 final class SystemRandomImpl extends SystemRandom { 30 31 static { 32 staticInit0(); 33 } 34 35 /** 36 * Native code keeps a HCRYPTPROV cryptographic provider handle here. 37 * (see windows/native/libjava/SystemRandomImpl_md.c) 38 */ 39 @SuppressWarnings("UnusedDeclaration") 40 private long cryptProvider; 41 42 private boolean closed; 43 private final Object lock = new Object(); 44 45 SystemRandomImpl() { 46 synchronized (lock) { 47 if (!init0()) { 48 closed = true; 49 throw new UnsupportedOperationException("Cryptographic Provider not available."); 50 } 51 } 52 } 53 54 @Override 55 public void getBytes(byte[] bytes) { 56 if (bytes == null) throw new NullPointerException(); 57 synchronized (lock) { 58 if (closed) { 59 throw new IllegalStateException("Already closed."); 60 } 61 getBytes0(bytes); 62 } 63 } 64 65 @Override 66 public void close() { 67 synchronized (lock) { 68 if (!closed) { 69 close0(); 70 closed = true; 71 } 72 } 73 } 74 75 /** 76 * In case user fails to call close() explicitly, 77 * it is called when object is finalized. 78 */ 79 @Override 80 protected void finalize() { 81 close(); 82 } 83 84 // native methods (see windows/native/libjava/SystemRandomImpl_md.c) 85 86 private static native void staticInit0(); 87 88 private native boolean init0(); 89 90 private native void getBytes0(byte[] bytes); 91 92 private native void close0(); 93 }