org.codice.ddf.platform.util.RandomNumberGenerator.java Source code

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Here is the source code for org.codice.ddf.platform.util.RandomNumberGenerator.java

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/**
 * Copyright (c) Codice Foundation
 * <p>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p>
 * This program 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
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package org.codice.ddf.platform.util;

import java.security.SecureRandom;

import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.prng.BasicEntropySourceProvider;
import org.bouncycastle.crypto.prng.EntropySourceProvider;
import org.bouncycastle.crypto.prng.drbg.DualECSP800DRBG;

public class RandomNumberGenerator {

    public static SecureRandom create() {
        return new SecureRandom(createSeed());
    }

    public static byte[] createSeed() {
        EntropySourceProvider esp = new BasicEntropySourceProvider(new SecureRandom(), true);
        byte[] nonce = new byte[256];
        new SecureRandom().nextBytes(nonce);

        DualECSP800DRBG bcRbg = new DualECSP800DRBG(new SHA256Digest(), 256, esp.get(256), null, nonce);
        byte[] seed = new byte[256];
        bcRbg.generate(seed, null, true);
        return seed;
    }
}