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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  import javax.crypto.KeyGenerator;
22  import java.security.Key;
23  import java.security.NoSuchAlgorithmException;
24  
25  /**
26   * Base abstract class for supporting symmetric key cipher algorithms.
27   *
28   * @since 1.0
29   */
30  public abstract class AbstractSymmetricCipherService extends JcaCipherService {
31  
32      protected AbstractSymmetricCipherService(String algorithmName) {
33          super(algorithmName);
34      }
35  
36      /**
37       * Generates a new {@link java.security.Key Key} suitable for this CipherService's {@link #getAlgorithmName() algorithm}
38       * by calling {@link #generateNewKey(int) generateNewKey(128)} (uses a 128 bit size by default).
39       *
40       * @return a new {@link java.security.Key Key}, 128 bits in length.
41       */
42      public Key generateNewKey() {
43          return generateNewKey(getKeySize());
44      }
45  
46      /**
47       * Generates a new {@link Key Key} of the specified size suitable for this CipherService
48       * (based on the {@link #getAlgorithmName() algorithmName} using the JDK {@link javax.crypto.KeyGenerator KeyGenerator}.
49       *
50       * @param keyBitSize the bit size of the key to create
51       * @return the created key suitable for use with this CipherService
52       */
53      public Key generateNewKey(int keyBitSize) {
54          KeyGenerator kg;
55          try {
56              kg = KeyGenerator.getInstance(getAlgorithmName());
57          } catch (NoSuchAlgorithmException e) {
58              String msg = "Unable to acquire " + getAlgorithmName() + " algorithm.  This is required to function.";
59              throw new IllegalStateException(msg, e);
60          }
61          kg.init(keyBitSize);
62          return kg.generateKey();
63      }
64  
65  }