Java tutorial
/* * Copyright (C) 2015 The Workbench Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.cloudkit.enterprises.infrastructure.utilities; import org.apache.commons.lang3.Validate; import java.io.IOException; import java.io.InputStream; import java.security.GeneralSecurityException; import java.security.MessageDigest; import java.security.SecureRandom; /** * ?SHA-1/MD5??. * ByteSource??Hex, Base64UrlSafeBase64 * * @author hongquanli <hongquanli@qq.com> * @version 1.0 20131121 ?2:59:50 */ public class DigestsHelper { private static final String SHA1 = "SHA-1"; private static final String MD5 = "MD5"; private static SecureRandom random = new SecureRandom(); /** * sha1. */ public static byte[] sha1(byte[] input) { return digest(input, SHA1, null, 1); } public static byte[] sha1(byte[] input, byte[] salt) { return digest(input, SHA1, salt, 1); } public static byte[] sha1(byte[] input, byte[] salt, int iterations) { return digest(input, SHA1, salt, iterations); } /** * , ?md5sha1. */ private static byte[] digest(byte[] input, String algorithm, byte[] salt, int iterations) { try { MessageDigest digest = MessageDigest.getInstance(algorithm); if (salt != null) { digest.update(salt); } byte[] result = digest.digest(input); for (int i = 1; i < iterations; i++) { digest.reset(); result = digest.digest(result); } return result; } catch (GeneralSecurityException e) { throw ExceptionHelper.unchecked(e); } } /** * ??Byte[]salt. * * @param numBytes byte? */ public static byte[] generateSalt(int numBytes) { Validate.isTrue(numBytes > 0, "numBytes argument must be a positive integer (1 or larger)", numBytes); byte[] bytes = new byte[numBytes]; random.nextBytes(bytes); return bytes; } /** * md5. */ public static byte[] md5(InputStream input) throws IOException { return digest(input, MD5); } /** * sha1. */ public static byte[] sha1(InputStream input) throws IOException { return digest(input, SHA1); } private static byte[] digest(InputStream input, String algorithm) throws IOException { try { MessageDigest messageDigest = MessageDigest.getInstance(algorithm); int bufferLength = 8 * 1024; byte[] buffer = new byte[bufferLength]; int read = input.read(buffer, 0, bufferLength); while (read > -1) { messageDigest.update(buffer, 0, read); read = input.read(buffer, 0, bufferLength); } return messageDigest.digest(); } catch (GeneralSecurityException e) { throw ExceptionHelper.unchecked(e); } } }