1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.shiro.crypto;
20
21 /**
22 * {@code CipherService} using the {@code Blowfish} cipher algorithm for all encryption, decryption, and key operations.
23 * <p/>
24 * The Blowfish algorithm can support key sizes between {@code 32} and {@code 448} bits<b>*</b>, inclusive. However,
25 * modern cryptanalysis techniques render keys of 80 bits or less mostly worthless - use {@code 128} or more whenever
26 * possible.
27 * <p/>
28 * Note that this class retains the parent class's default {@link OperationMode#CBC CBC} mode of operation
29 * instead of the typical JDK default of {@link OperationMode#ECB ECB}. {@code ECB} should not be used in
30 * security-sensitive environments because {@code ECB} does not allow for initialization vectors, which are
31 * considered necessary for strong encryption. See the {@link DefaultBlockCipherService parent class}'s JavaDoc and the
32 * {@link JcaCipherService JcaCipherService} JavaDoc for more on why the JDK default should not be used and is not
33 * used in this implementation.
34 * <p/>
35 * <b>*</b> Generating and using Blowfish key sizes greater than 128 require installation of the
36 * <a href="http://java.sun.com/javase/downloads/index.jsp">Java Cryptography Extension (JCE) Unlimited Strength
37 * Jurisdiction Policy files</a>.
38 *
39 * @since 1.0
40 */
41 public class BlowfishCipherService extends DefaultBlockCipherService {
42
43 private static final String ALGORITHM_NAME = "Blowfish";
44 private static final int BLOCK_SIZE = 64;
45
46 /**
47 * Creates a new {@link CipherService} instance using the {@code Blowfish} cipher algorithm with the following
48 * important cipher default attributes:
49 * <table>
50 * <tr>
51 * <th>Attribute</th>
52 * <th>Value</th>
53 * </tr>
54 * <tr>
55 * <td>{@link #setKeySize keySize}</td>
56 * <td>{@code 128} bits</td>
57 * </tr>
58 * <tr>
59 * <td>{@link #setBlockSize blockSize}</td>
60 * <td>{@code 64} bits (required for {@code Blowfish})</td>
61 * </tr>
62 * <tr>
63 * <td>{@link #setMode mode}</td>
64 * <td>{@link OperationMode#CBC CBC}<b>*</b></td>
65 * </tr>
66 * <tr>
67 * <td>{@link #setPaddingScheme paddingScheme}</td>
68 * <td>{@link PaddingScheme#PKCS5 PKCS5}</td>
69 * </tr>
70 * <tr>
71 * <td>{@link #setInitializationVectorSize(int) initializationVectorSize}</td>
72 * <td>{@code 64} bits</td>
73 * </tr>
74 * <tr>
75 * <td>{@link #setGenerateInitializationVectors(boolean) generateInitializationVectors}</td>
76 * <td>{@code true}<b>**</b></td>
77 * </tr>
78 * </table>
79 * <p/>
80 * <b>*</b> The {@link OperationMode#CBC CBC} operation mode is used instead of the JDK default {@code ECB} to
81 * ensure strong encryption. {@code ECB} should not be used in security-sensitive environments - see the
82 * {@link DefaultBlockCipherService DefaultBlockCipherService} class JavaDoc's "Operation Mode" section
83 * for more.
84 * <p/>
85 * <b>**</b>In conjunction with the default {@code CBC} operation mode, initialization vectors are generated by
86 * default to ensure strong encryption. See the {@link JcaCipherService JcaCipherService} class JavaDoc for more.
87 */
88 public BlowfishCipherService() {
89 super(ALGORITHM_NAME);
90 setInitializationVectorSize(BLOCK_SIZE); //like most block ciphers, the IV size is the same as the block size
91 }
92 }