001 /** 002 * Copyright (c) 2000-2013 Liferay, Inc. All rights reserved. 003 * 004 * This library is free software; you can redistribute it and/or modify it under 005 * the terms of the GNU Lesser General Public License as published by the Free 006 * Software Foundation; either version 2.1 of the License, or (at your option) 007 * any later version. 008 * 009 * This library is distributed in the hope that it will be useful, but WITHOUT 010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 011 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 012 * details. 013 */ 014 015 package com.liferay.portal.kernel.security; 016 017 import java.util.Random; 018 019 /** 020 * @author Shuyang Zhou 021 */ 022 public class SecureRandom extends Random { 023 024 @Override 025 protected int next(int bits) { 026 int bytes = (bits + 7) / 8; 027 028 int result = SecureRandomUtil.nextByte(); 029 030 for (int i = 1; i < bytes; i++) { 031 result = (result << 8) + (SecureRandomUtil.nextByte() & 0xFF); 032 } 033 034 return result >>> (bytes * 8 - bits); 035 } 036 037 }