/*

  * 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.shiro.crypto;

 import javax.crypto.KeyGenerator;

 import java.security.Key;

 import java.security.NoSuchAlgorithmException;

 /**

  * Base abstract class for supporting symmetric key cipher algorithms.

  *

  * @since 1.0

  */

 public abstract class AbstractSymmetricCipherService extends JcaCipherService {

     protected AbstractSymmetricCipherService(String algorithmName) {

         super(algorithmName);

     }

     /**

      * Generates a new {@link java.security.Key Key} suitable for this CipherService's {@link #getAlgorithmName() algorithm}

      * by calling {@link #generateNewKey(int) generateNewKey(128)} (uses a 128 bit size by default).

      *

      * @return a new {@link java.security.Key Key}, 128 bits in length.

      */

     public Key generateNewKey() {

         return generateNewKey(getKeySize());

     }

     /**

      * Generates a new {@link Key Key} of the specified size suitable for this CipherService

      * (based on the {@link #getAlgorithmName() algorithmName} using the JDK {@link javax.crypto.KeyGenerator KeyGenerator}.

      *

      * @param keyBitSize the bit size of the key to create

      * @return the created key suitable for use with this CipherService

      */

     public Key generateNewKey(int keyBitSize) {

         KeyGenerator kg;

         try {

             kg = KeyGenerator.getInstance(getAlgorithmName());

         } catch (NoSuchAlgorithmException e) {

             String msg = "Unable to acquire " + getAlgorithmName() + " algorithm.  This is required to function.";

             throw new IllegalStateException(msg, e);

         }

         kg.init(keyBitSize);

         return kg.generateKey();

     }

 }