001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.core.random;
018
019import java.security.SecureRandom;
020import java.util.Base64;
021
022/**
023 * Supplies the Wicket application with random bytes.
024 * 
025 * @author papegaaij
026 */
027public interface ISecureRandomSupplier
028{
029        /**
030         * Returns the actual {@code SecureRandom} being used as source.
031         * 
032         * @return The {@code SecureRandom}.
033         */
034        SecureRandom getRandom();
035
036        /**
037         * Returns a byte array with random bytes of the given length.
038         * 
039         * @param length
040         *            The number of bytes to return.
041         * @return A byte array with random bytes of the given length.
042         */
043        default byte[] getRandomBytes(int length)
044        {
045                byte[] ret = new byte[length];
046                getRandom().nextBytes(ret);
047                return ret;
048        }
049        
050        /**
051         * Returns a url-base64 encoded string with random content, base on {@code length} bytes. The
052         * length of the returned string will be {@code length/3*4}.
053         * 
054         * @param length
055         *            The number of random bytes to use as input.
056         * @return A string with random base64 data.
057         */
058        default String getRandomBase64(int length)
059        {
060                return Base64.getUrlEncoder().encodeToString(getRandomBytes(length));
061        }
062}