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 * Copyright (c) 2003, 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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 */

/**

 * @test

 * @bug 4915392 8141039

 * @summary test that the getAlgorithm() method works correctly

 * @author Andreas Sterbenz

 * @run main GetAlgorithm

 */

import java.io.*;

import java.security.*;

import java.util.Arrays;

import java.util.List;

public class GetAlgorithm {

    private static final String BASE = System.getProperty("test.src", ".");

    private static final String DRBG_CONFIG = "securerandom.drbg.config";

    private static final String DRBG_CONFIG_VALUE

            = Security.getProperty(DRBG_CONFIG);

    public static void main(String[] args) throws Exception {

        SecureRandom sr = new SecureRandom();

        if (sr.getAlgorithm().equals("unknown")) {

            throw new Exception("Unknown: " + sr.getAlgorithm());

        }

        for (String mech : new String[]{supportedNativeAlgo(), "SHA1PRNG",

            "Hash_DRBG", "HMAC_DRBG", "CTR_DRBG"}) {

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

                check(mech, SecureRandom.getInstance(mech));

            } else {

                try {

                    Security.setProperty(DRBG_CONFIG, mech);

                    check("DRBG", SecureRandom.getInstance("DRBG"));

                } finally {

                    Security.setProperty(DRBG_CONFIG, DRBG_CONFIG_VALUE);

                }

            }

        }

        check("unknown", new MySecureRandom());

        InputStream in = new FileInputStream(

                new File(BASE, "sha1prng-old.bin"));

        ObjectInputStream oin = new ObjectInputStream(in);

        sr = (SecureRandom) oin.readObject();

        oin.close();

        check("unknown", sr);

        in = new FileInputStream(new File(BASE, "sha1prng-new.bin"));

        oin = new ObjectInputStream(in);

        sr = (SecureRandom) oin.readObject();

        oin.close();

        check("SHA1PRNG", sr);

        System.out.println("All tests passed");

    }

    private static void check(String s1, SecureRandom sr) throws Exception {

        String s2 = sr.getAlgorithm();

        if (s1.equals(s2) == false) {

            throw new Exception("Expected " + s1 + ", got " + s2);

        }

    }

    private static class MySecureRandom extends SecureRandom {

    }

    /**

     * Find the name of supported native mechanism name for current platform.

     */

    private static String supportedNativeAlgo() {

        String nativeSr = "Windows-PRNG";

        try {

            SecureRandom.getInstance(nativeSr);

        } catch (NoSuchAlgorithmException e) {

            nativeSr = "NativePRNG";

        }

        return nativeSr;

    }

}