1 /*
2 * Licensed to The Apereo Foundation under one or more contributor license
3 * agreements. See the NOTICE file distributed with this work for additional
4 * information regarding copyright ownership.
5 *
6 *
7 * The Apereo Foundation licenses this file to you under the Educational
8 * Community License, Version 2.0 (the "License"); you may not use this file
9 * except in compliance with the License. You may obtain a copy of the License
10 * at:
11 *
12 * http://opensource.org/licenses/ecl2.txt
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
17 * License for the specific language governing permissions and limitations under
18 * the License.
19 *
20 */
21 package org.opencastproject.urlsigning.utils;
22
23 import org.apache.commons.codec.binary.Hex;
24
25 import java.io.UnsupportedEncodingException;
26 import java.nio.charset.StandardCharsets;
27 import java.security.InvalidKeyException;
28 import java.security.NoSuchAlgorithmException;
29
30 import javax.crypto.Mac;
31 import javax.crypto.spec.SecretKeySpec;
32
33 /**
34 * A utility class to hash plain text with the SHA-256 algorithm.
35 */
36 public final class SHA256Util {
37 /** The algorithm to use to encode the HMAC. */
38 private static final String ALGORITHM = "HmacSHA256";
39
40 private SHA256Util() {
41 }
42
43 /**
44 * Create a SHA 256 digest string from a string and a secret key.
45 *
46 * @param plainText
47 * The plaintext string to hash.
48 * @param secretKey
49 * The key to use to create the hash.
50 * @return Returns a hash of the plain text hashed with the secret key.
51 * @throws NoSuchAlgorithmException
52 * Thrown if the algorithm is not supported on this platform.
53 * @throws InvalidKeyException
54 * Thrown if the secret key is invalid.
55 * @throws UnsupportedEncodingException
56 * Thrown if unable to convert bytes into a hex string.
57 */
58 public static String digest(String plainText, String secretKey) throws NoSuchAlgorithmException, InvalidKeyException,
59 UnsupportedEncodingException {
60 SecretKeySpec key = new SecretKeySpec((secretKey).getBytes(StandardCharsets.UTF_8), ALGORITHM);
61 Mac mac = Mac.getInstance(ALGORITHM);
62 mac.init(key);
63 byte[] bytes = mac.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
64
65 // Convert raw bytes to Hex
66 byte[] hexBytes = new Hex().encode(bytes);
67
68 // Covert array of Hex bytes to a String
69 return new String(hexBytes, "UTF-8");
70 }
71 }