1 /*
   2  * Copyright (c) 1998, 2003, 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 /**
  25  * @test
  26  * @bug 4168409
  27  * @summary SecureRandom forces all instances to self-seed, even if a seed is
  28  *                      provided
  29  */
  30 
  31 import java.security.SecureRandom;
  32 
  33 public class SelfSeed {
  34 
  35     private static final int NUM_BYTES = 5;
  36     private static byte seed[] = { (byte)0xaa, (byte)0x11, (byte)0xa1 };
  37 
  38     public static void main(String[] args) {
  39 
  40         try {
  41             SecureRandom sr1 = SecureRandom.getInstance("SHA1PRNG");
  42             sr1.setSeed(seed);
  43             byte randomBytes[] = new byte[NUM_BYTES];
  44             sr1.nextBytes(randomBytes);
  45 
  46             SecureRandom sr2 = new SecureRandom(seed);
  47             if (sr2.getAlgorithm().equals("SHA1PRNG") == false) {
  48                 System.out.println("Default PRNG is not SHA1PRNG, skipping test");
  49                 return;
  50             }
  51             byte otherRandomBytes[] = new byte[NUM_BYTES];
  52             sr2.nextBytes(otherRandomBytes);
  53 
  54             // make sure the random bytes generated are the same
  55             for (int i = 0; i < NUM_BYTES; i++) {
  56                 if (randomBytes[i] != otherRandomBytes[i])
  57                     throw new SecurityException("FAILURE: " +
  58                                         "Returned bytes not equal");
  59             }
  60 
  61             // success
  62         } catch (Exception e) {
  63             throw new SecurityException("FAILURE: " + e.toString());
  64         }
  65     }
  66 }