1 /*
   2  * Copyright (c) 2010, 2016, 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 6998583 8141039
  27  * @summary NativeSeedGenerator is making 8192 byte read requests from
  28  *             entropy pool on each init.
  29  * @run main/othervm -Djava.security.egd=file:/dev/random SeedGeneratorChoice
  30  * @run main/othervm -Djava.security.egd=file:filename  SeedGeneratorChoice
  31  */
  32 
  33 /*
  34  * Side testcase introduced to ensure changes for 6998583 will always
  35  * succeed in falling back to ThreadedSeedGenerator if issues are found
  36  * with the native OS generator request. We should never see an exception
  37  * causing exit.
  38  * We should always fall back to the ThreadedSeedGenerator if exceptions
  39  * are encountered with user defined source of entropy.
  40  */
  41 import java.security.SecureRandom;
  42 import java.security.Security;
  43 
  44 public class SeedGeneratorChoice {
  45 
  46     public static void main(String... arguments) throws Exception {
  47         for (String mech : new String[]{"SHA1PRNG", "Hash_DRBG", "HMAC_DRBG",
  48             "CTR_DRBG"}) {
  49 
  50             SecureRandom prng = null;
  51             if (!mech.contains("_DRBG")) {
  52                 prng = SecureRandom.getInstance(mech);
  53             } else {
  54                 Security.setProperty("securerandom.drbg.config", mech);
  55                 prng = SecureRandom.getInstance("DRBG");
  56             }
  57             prng.generateSeed(1);
  58         }
  59     }
  60 
  61 }