1 /*
   2  * Copyright (c) 1998, 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 /* @test
  25  * @bug 4102896
  26  * @summary Make sure that a SecureRandom object can be serialized
  27  */
  28 
  29 import java.security.*;
  30 import java.io.*;
  31 
  32 public class Serialize {
  33 
  34     public static void main(String args[]) throws Exception {
  35         for (String alg: new String[]{
  36                 "SHA1PRNG", "DRBG", "Hash_DRBG", "HMAC_DRBG", "CTR_DRBG"}) {
  37             System.out.println("Testing " + alg);
  38 
  39             // Even unseeded object can be serialized and deserialized
  40             SecureRandom s1 = getInstance(alg);
  41             revive(s1).nextInt();
  42             if (alg.contains("DRBG")) {
  43                 revive(s1).reseed();
  44             }
  45 
  46             // After seeded, deserialized object should emit same random data
  47             s1 = getInstance(alg);
  48             s1.nextInt();    // state set
  49             SecureRandom s2 = revive(s1);
  50             int n1 = s1.nextInt();
  51             int n2 = s2.nextInt();
  52             if (n1 != n2) {
  53                 throw new Exception();
  54             }
  55 
  56             // Or seeded with user-provided data
  57             s1.setSeed(42);
  58             s2.setSeed(42);
  59             n1 = s1.nextInt();
  60             n2 = s2.nextInt();
  61             if (n1 != n2) {
  62                 throw new Exception();
  63             }
  64 
  65             // But not after automatic reseed
  66             if (alg.contains("DRBG")) {
  67                 s1.reseed();
  68                 s2.reseed();
  69                 n1 = s1.nextInt();
  70                 n2 = s2.nextInt();
  71                 if (n1 == n2) {
  72                     throw new Exception();
  73                 }
  74             }
  75         }
  76     }
  77 
  78     private static SecureRandom getInstance(String alg) throws Exception {
  79         if (alg.equals("SHA1PRNG") || alg.equals("DRBG")) {
  80             return SecureRandom.getInstance(alg);
  81         } else {
  82             String old = Security.getProperty("drbg");
  83             try {
  84                 Security.setProperty("drbg", alg);
  85                 return SecureRandom.getInstance("DRBG");
  86             } finally {
  87                 Security.setProperty("drbg", old);
  88             }
  89         }
  90     }
  91 
  92     private static SecureRandom revive(SecureRandom sr) throws Exception {
  93         ByteArrayOutputStream bout = new ByteArrayOutputStream();
  94         new ObjectOutputStream(bout).writeObject(sr);
  95         return (SecureRandom) new ObjectInputStream(
  96                 new ByteArrayInputStream(bout.toByteArray())).readObject();
  97     }
  98 }