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 * 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;
    }

}