PwmRandom.java

/*
 * Password Management Servlets (PWM)
 * http://www.pwm-project.org
 *
 * Copyright (c) 2006-2009 Novell, Inc.
 * Copyright (c) 2009-2017 The PWM Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package password.pwm.util.secure;

import java.security.SecureRandom;
import java.util.UUID;

public class PwmRandom {

    private final SecureRandom internalRand = new SecureRandom();

    private static final PwmRandom SINGLETON = new PwmRandom();

    private static final String ALPHANUMERIC_STRING = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

    private PwmRandom() {
    }

    public static PwmRandom getInstance() {
        return SINGLETON;
    }

    public long nextLong() {
        return internalRand.nextLong();
    }

    public int nextInt() {
        return internalRand.nextInt();
    }

    public int nextInt(final int n) {
        return internalRand.nextInt(n);
    }

    public boolean nextBoolean() {
        return internalRand.nextBoolean();
    }

    public String getAlgorithm() {
        return internalRand.getAlgorithm();
    }

    public String alphaNumericString(final int length) {
        return alphaNumericString(ALPHANUMERIC_STRING,length);
    }

    public String alphaNumericString(final String characters, final int length) {
        final StringBuilder sb = new StringBuilder();
        while (sb.length() < length) {
            sb.append(nextChar(characters));
        }
        return sb.toString();
    }

    public char nextChar() {
        return nextChar(ALPHANUMERIC_STRING);
    }

    public char nextChar(final String characters) {
        if (characters == null) {
            throw new NullPointerException("characters cannot be null");
        }
        return characters.charAt(nextInt(characters.length()));
    }

    public void nextBytes(final byte[] secArray)
    {
        internalRand.nextBytes(secArray);
    }

    public UUID randomUUID() {
        return UUID.randomUUID();
    }

    public byte[] newBytes(final int length) {
        final byte[] newBytes = new byte[length];
        nextBytes(newBytes);
        return newBytes;
    }
}