1 /* 2 * Copyright (C) 2022 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server.locksettings; 18 19 import java.security.SecureRandom; 20 21 /** Utilities using a static SecureRandom */ 22 public class SecureRandomUtils { 23 private static final SecureRandom RNG = new SecureRandom(); 24 25 /** Use SecureRandom to generate `length` random bytes */ randomBytes(int length)26 public static byte[] randomBytes(int length) { 27 byte[] res = new byte[length]; 28 RNG.nextBytes(res); 29 return res; 30 } 31 32 /** Use SecureRandom to generate a random long */ randomLong()33 public static long randomLong() { 34 return RNG.nextLong(); 35 } 36 } 37