| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.sqoop.util; |
| |
| import java.rmi.server.UID; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| |
| /** |
| * Securely generate random MD5 signatures for use as nonce values. |
| */ |
| public final class RandomHash { |
| |
| private RandomHash() { } |
| |
| /** |
| * Generate a new random md5 hash. |
| * @return a securely-generated random 16 byte sequence. |
| */ |
| public static byte [] generateMD5Bytes() { |
| try { |
| MessageDigest digester = MessageDigest.getInstance("MD5"); |
| long time = System.currentTimeMillis(); |
| digester.update((new UID() + "@" + time).getBytes()); |
| return digester.digest(); |
| } catch (NoSuchAlgorithmException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * Generate a new random md5 hash and convert it to a string. |
| * @return a securely-generated random string. |
| */ |
| public static String generateMD5String() { |
| byte [] bytes = generateMD5Bytes(); |
| StringBuilder sb = new StringBuilder(); |
| for (byte b : bytes) { |
| int x = ((int) b) & 0xFF; |
| sb.append(String.format("%02x", x)); |
| } |
| return sb.toString(); |
| } |
| } |
| |