/*

 * Copyright (c) 2010, 2011, 2016, 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.

 *

 * 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

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 * questions.

 */

/*

 * @test

 * @bug 6998583 8141039

 * @summary NativeSeedGenerator is making 8192 byte read requests from

 *             entropy pool on each init.

 * @run main/othervm -Djava.security.egd=file:/dev/random SeedGeneratorChoice

 * @run main/othervm -Djava.security.egd=file:filename  SeedGeneratorChoice

 */

/*

 * Side testcase introduced to ensure changes for 6998583 will always

 * succeed in falling back to ThreadedSeedGenerator if issues are found

 * with the native OS generator request. We should never see an exception

 * causing exit.

 * We should always fall back to the ThreadedSeedGenerator if exceptions

 * are encountered with user defined source of entropy.

 */

import java.security.SecureRandom;

import java.security.Security;

public class SeedGeneratorChoice {

    public static void main(String... arguments) throws Exception {

        for (String mech : new String[]{"SHA1PRNG", "Hash_DRBG", "HMAC_DRBG",

            "CTR_DRBG"}) {

            SecureRandom prng = null;

            if (!mech.contains("_DRBG")) {

                prng = SecureRandom.getInstance(mech);

            } else {

                Security.setProperty("securerandom.drbg.config", mech);

                prng = SecureRandom.getInstance("DRBG");

            }

            prng.generateSeed(1);

        }

    }

}