2 * ============LICENSE_START==========================================
4 * ===================================================================
5 * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
6 * Copyright © 2017-2018 Amdocs
7 * ===================================================================
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
12 * http://www.apache.org/licenses/LICENSE-2.0
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 * ============LICENSE_END============================================
21 package org.onap.champ.util;
23 import java.io.ByteArrayOutputStream;
24 import java.io.IOException;
25 import java.io.ObjectOutput;
26 import java.io.ObjectOutputStream;
27 import java.security.MessageDigest;
28 import java.security.NoSuchAlgorithmException;
30 * Generates a sha 256 hash
32 public class HashGenerator {
33 private MessageDigest messageDigest;
35 public HashGenerator() throws NoSuchAlgorithmException {
36 this.messageDigest = MessageDigest.getInstance("SHA-256");
40 * Generates a SHA 256 hash as a hexadecimal string for the inputs.
41 * Calls toString on the input objects to convert into a byte stream.
43 * @return SHA 256 hash of the inputs as a hexadecimal string.
46 public String generateSHA256AsHex(Object... values) throws IOException {
47 byte[] bytes = convertToBytes(values);
48 byte[] digest = messageDigest.digest(bytes);
49 StringBuilder result = new StringBuilder();
50 for (byte byt : digest) result.append(Integer.toString((byt & 0xff) + 0x100, 16).substring(1));
51 return result.toString();
54 private byte[] convertToBytes(Object... values) throws IOException {
55 try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
56 ObjectOutput out = new ObjectOutputStream(bos)) {
57 for (Object object : values) {
58 out.writeObject(object.toString());
60 return bos.toByteArray();