| /* |
| * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.security.mscapi; |
| |
| import java.security.ProviderException; |
| import java.security.SecureRandomSpi; |
| |
| /** |
| * Native PRNG implementation for Windows using the Microsoft Crypto API. |
| * |
| * @since 1.6 |
| */ |
| |
| public final class PRNG extends SecureRandomSpi |
| implements java.io.Serializable { |
| |
| private static final long serialVersionUID = 4129268715132691532L; |
| |
| /* |
| * The CryptGenRandom function fills a buffer with cryptographically random |
| * bytes. |
| */ |
| private static native byte[] generateSeed(int length, byte[] seed); |
| |
| /** |
| * Creates a random number generator. |
| */ |
| public PRNG() { |
| } |
| |
| /** |
| * Reseeds this random object. The given seed supplements, rather than |
| * replaces, the existing seed. Thus, repeated calls are guaranteed |
| * never to reduce randomness. |
| * |
| * @param seed the seed. |
| */ |
| @Override |
| protected void engineSetSeed(byte[] seed) { |
| if (seed != null) { |
| generateSeed(-1, seed); |
| } |
| } |
| |
| /** |
| * Generates a user-specified number of random bytes. |
| * |
| * @param bytes the array to be filled in with random bytes. |
| */ |
| @Override |
| protected void engineNextBytes(byte[] bytes) { |
| if (bytes != null) { |
| if (generateSeed(0, bytes) == null) { |
| throw new ProviderException("Error generating random bytes"); |
| } |
| } |
| } |
| |
| /** |
| * Returns the given number of seed bytes. This call may be used to |
| * seed other random number generators. |
| * |
| * @param numBytes the number of seed bytes to generate. |
| * |
| * @return the seed bytes. |
| */ |
| @Override |
| protected byte[] engineGenerateSeed(int numBytes) { |
| byte[] seed = generateSeed(numBytes, null); |
| |
| if (seed == null) { |
| throw new ProviderException("Error generating seed bytes"); |
| } |
| return seed; |
| } |
| } |